UC-NRLF 
 
 C 3 D37 MOD 
 
MEDICAL SCH<S>L 
 LflTOAI&Y 
 
 EX 1 1BKIS ffi 
 
 MEMORIAM 
 DR. JOHN MARSHALL WILLIAMS! 
 
INCLUDING A SPECIAL SECTION ON THE 
 FUNDAMENTAL PRINCIPLES OF ANATOMY 
 
 EDITED HY 
 
 W. T. ECKLEY, M. D. 
 
 I'KOFESSOK OF ANATOMY IN THE COLLEGE OF PHYSICIANS AND SURGEONS, UNIVERSITY OF ILLINOIS ; PROFESSOR OF ANATOMY 
 IN THE NORTHWESTERN UNIVERSITY DENTAL SCHOOL; PROFESSOR OF ANATOMY IN THE CHICAGO CLINICAL 
 SCHOOL, AND DIRECTOR OF THE CHICAGO SCHOOL OF ANATOMY AND PHYSIOLOGY; MEMBER 
 OF THE AMERICAN MEDICAL ASSOCIATION, THE CHICAGO PATHOLOGICAL 
 SOCIETY, THE CHICAGO MEDICAL SOCIETY, THE MEDICO- 
 LEGAL SOCIETY OF CHICAGO, ETC. 
 
 AND 
 
 MRS. CORINNE BUFORD ECKLEY 
 
 INSTRUCTOR IN ANATOMY IN THE NORTHWESTERN UNIVERSITY DENTAL SCHOOL; PROFESSOR OF ANATOMY IN THE 
 
 NORTHWESTERN UNIVERSITY WOMAN'S MEDICAL SCHOOL; PROFESSOR OF ANATOMY IN THE 
 
 CHICAGO SCHOOL OF ANATOMY AND PHYSIOLOGY 
 
 WITH 347 ILLUSTRATIONS, MANY OF WHICH ARE IN COLORS 
 
 PHILADELPHIA 
 
 P. BLAKISTON'S SON & CO. 
 
 1012 WALNUT STREET 
 1899 
 
COPYRIGHT, 1899, BY P. BLAKISTON'S SON & Co. 
 
 PRESS OF WM. F. FELL & Co., 
 
 !22O-24 SANSOM ST., 
 
 PHILADELPHIA. 
 
PREFACE 
 
 We have the honor of submitting this little book as a dissecting-room guide 
 to " Morris' Human Anatomy." 
 
 The growing tendency to specialize in the practice of medicine has reacted 
 on the branch of medical science that continges every medical specialty anatomy ; 
 with the result that our schools are compelled to keep pace in teaching this 
 branch. 
 
 Those areas of the body that can not, under existing conditions, be profitably 
 studied in the dissecting-room are properly presented by the lecturer on anatomy. 
 Thus the student has the benefit of the professor's dissections and investigation, 
 and the additional opportunity for minute, detailed dissection and study, which 
 he could not enjoy in the dissecting-room, where gross anatomy is the main 
 topic. The minute and descriptive anatomy are, then, to be studied in Morris. 
 
 In this book the gross anatomy only will be considered. For instance, the 
 contents of the orbit, as the nerves, vessels, muscles, as found on the cadaver, 
 will be considered, but the anatomy of the eyeball will not be taken up. The 
 gross anatomy of the peritoneum and other abdominal contents will be con- 
 sidered, while the student will be referred to Morris for the special anatomy of 
 each individual organ. 
 
 Several pages have been devoted to the sympathetic nerve, which every 
 student should thoroughly dissect, for the purpose only of teaching the student 
 to find on the cadaver the relation between sympathetic and their parent somatic 
 nerves. 
 
 The method of studying structures in the normal order in which they are 
 exposed in dissection is followed, it is believed, as nearly as it is possible to 
 accomplish this very desirable end. 
 
 To aid the memory in fixing salient points seen in dissection, frequent review 
 quizzes are given. 
 
 In the introductory chapter are certain rules, principles, and generalizations 
 which underly, to greater or less extent, the science of anatomy. It may be 
 urged that matters of this nature are too elementary for medical students. How- 
 ever this may be, experience teaches that students, even after having studied the 
 subject for months, have a memory well stored with anatomical terms which are 
 mere abstract ideas ; they are too often ignorant of the fundamental principles 
 of our nomenclature. 
 
 If anatomy is a nomenclaturic science [Can any department of learning be a 
 science without a nomenclature?] then certainly the place for the student to 
 
 285 "'6 
 
iv PREFA CE. 
 
 learn this nomenclature is in school. The practice ot assuming too much knowl- 
 edge on the part of the student I believe to be wrong in principle. At any rate, 
 we must remember that this book is written, not for those who know anatomy, 
 but for beginners. 
 
 To impress on the student the necessity of tracing muscles to their exact 
 origin and insertion, illustrations of bones having such attachments indicated in 
 color have been introduced. These and nearly all other illustrations are from 
 the work to which the text most frequently refers " Morris' Anatomy." We 
 wish also to express our thanks to both author and publisher for the use of the 
 excellent diagrams from Potter's " Compend of Anatomy," and for the many 
 illustrations of the muscles taken from Gould's (Illustrated) " Medical Dic- 
 tionary." In addition to these we have contributed about sixty original draw- 
 ings, for the most part diagrammatic. We wish also to express our thanks to 
 Dr. Theodor Tieken, Dr. F. R. Sherwood, and Dr. D. Loring for valuable 
 suggestions and to Dr. W. A. Mansfield in particular, who read the original 
 copy and made timely corrections. 
 
 A book that would fail to give due consideration to those structures of the 
 body which can be easily demonstrated on the cadaver by any careful student 
 would fall short of the objects of this work. A book that would attempt in 
 approximately 400 pages to give the same that Morris devotes 1400 pages to, 
 would, to be charitable, be just 1000 pages too small. 
 
 The sequence of structures revealed by dissection, and the great number of 
 illustrations in the book, render an index almost superfluous. In fact, by the 
 aid of the description of the illustration a given muscle or vessel can be found 
 with certainty, even without an index. Still, to make the book as convenient 
 as possible, a brief index is appended. 
 
 W. T. ECKLEY. 
 
 C. B. ECKLEY. 
 5816 SOUTH PARK AVE., CHICAGO. 
 
CONTENTS. 
 
 PACK 
 
 FUNDAMENTAL PRINCIPLES OF ANATOMY, 9 
 
 Anatomical Nomenclature, , 9 
 
 Anatomical Tissues, The, 13 
 
 THE HEAD AND NECK, 27 
 
 Head, Bones of, 27 
 
 Nerves, 31 
 
 Muscles, 32 
 
 Arteries, 37 
 
 Veins, 39 
 
 Glands, 4 
 
 Neck, Superficial Dissection, 43 
 
 Deep Cervical Fascia, 47 
 
 Muscles, 49 
 
 Glands, 51 
 
 Second Layer of Deep Cervical Fascia, 53 
 
 Third Layer of Deep Cervical Fascia, 57 
 
 Veins, Arteries, and Nerves, 58 
 
 Mouth, The, 79 
 
 Structures Seen in Mouth, 79 
 
 Muscles of Mastication, 93 
 
 Soft Palate 98 
 
 Pharynx, 99 
 
 Larynx, 106 
 
 Nasal Fossae, The Internal Nose, m 
 
 Coverings of the Brain, 120 
 
 Tympanum, or Middle Ear, 13* 
 
 Blood-supply to the Brain, 135 
 
 Orbit and its Contents, 139 
 
 SHOULDER, ARM, FOREARM, AND HAND, 152 
 
 Hand, Bones of, 152 
 
 Veins, 154 
 
 Muscles, 160 
 
 Nerves, 162 
 
 Arteries, 166 
 
 Arm, Bones of, 168 
 
 Arteries, 173 
 
 Muscles, 174 
 
 Nerves, 181 
 
 Shoulder, Bones of, 186 
 
 Axillary Space, 188 
 
 Veins and Muscles, 189 
 
 Nerves, 195 
 
 Arteries, . 196 
 
 THE THORAX, 198 
 
 Muscles of, 200 
 
 Nerves, - 201 
 
 Arteries, 204 
 
 Interior of the Thorax, 204 
 
 Contents, 205 
 
 Arteries, 211 
 
 Veins, 212 
 
 Nerves, 214 
 
 THE ABDOMEN 225 
 
 The Walls, 225 
 
 Spermatic Cord, ... 231 
 
 Interior View of Abdominal Walls, 235 
 
 The Peritoneum, 238 
 
 Abdominal Contents, 246 
 
 The Sympathetic Nerve, 261 
 
 V 
 
vi CONTENTS. 
 
 THE PELVIS, CONTENTS OF, 274 
 
 The Diaphragm, 285 
 
 Female Generative Organs, 291 
 
 THIGH AND LEG, 297 
 
 Bones of, 297 
 
 Superficial Fascia, 302 
 
 Veins, Nerves, 305 
 
 Deep Fascia, 307 
 
 Anterior Region of the Leg, 310 
 
 Anterior and Internal Regions of the Thigh, 315 
 
 PELVIC OUTLET (MALE), 330 
 
 Muscles, 331 
 
 PELVIC OUTLET (FEMALE), 340 
 
 External and Internal Organs of Generation, 340 
 
 POSTERIOR PART OF SHOULDER, ARM, FOREARM, AND HAND, 345 
 
 Muscles, 353 
 
 Nerves 355 
 
 POSTERIOR PART OF LOWER EXTREMITY, 365 
 
 The Popliteal -Space, 366 
 
 Gluteal Region, .... 370 
 
 Arteries and Nerves, 372 
 
 Back Part of the Leg, 377 
 
 Sole of the Foot, 385 
 
 THE BACK, MUSCLES OF 394 
 
 Nerves, 397 
 
 Arteries, 398 
 
 SUMMARY OF CRANIAL NERVES, 398 
 
 ARTICULATIONS LIGAMENTS, 421 
 
 Table of Various Classes of Joints, 423 
 
 Pelvis Its Articulations and Ligaments, 453 
 
 Vertebral Column Its Articulations and Ligaments, 460 
 
 Thorax Its Articulations and Ligaments, 468 
 
 SOME INTERESTING FACTS ABOUT VF.INS 473 
 
 INDEX, 477 
 
LIST OF ILLUSTRATIONS. 
 
 1. Displacement of Cotton by Growing Plants, 16 
 
 2. Connective Tissue Displaced by the Artery, Nerve, and Vein, 16 
 
 3. Triangular Muscle, 18 
 
 4. Quadrangular Muscle, 18 
 
 5. fusiform Muscle, 18 
 
 6. Clubbed Muscle, 18 
 
 7. The Skull. (Norma lateralis.) {Coloured}, 27 
 
 8. The Mandible. (Outer view.) (Coloured}, 28 
 
 9. The Mandible. (Inner view.) (Coloured} 28 
 
 10. The Skull. (Norma facialis.) (Coloured}, 29 
 
 11. The Skull. (Norma basilaris.) (Coloured}, 30 
 
 12. Primary Incisions in Dissection of the Face, 3 2 
 
 13. The Deeper Layer of the Muscles of the Face and Neck, 33 
 
 14. The Superficial Muscles of the Head and Neck, 34 
 
 15. Scheme of Facial Nerve Communicating with the Fifth Cranial Nerve, .... After Potter 35 
 
 16. Superficial Distribution of the Facial and Other Nerves of the Head (Coloured}, 
 
 After Hirschfeld and Leveille 36 
 
 17. Scheme of the Facial Artery (Coloured}, 38 
 
 18. The Superficial Veins and Lymphatics of the Scalp, Face, and Neck (Coloured}, 39 
 
 19. Showing Schematically the Deep Part of the Parotid Gland Embracing the Styloid Process, . . 40 
 
 20. The Salivary Glands, 4 1 
 
 21. Cervical Triangles, 4 2 
 
 22. Superficial Branches of the Cervical Plexus (Coloured}, . . . After Hirschfeld and Leveille 46 
 
 23. Superficial Lymphatics, 47 
 
 24. Deep Cervical Fascia Transverse Section. Schematic, .' 48 
 
 25. Muscles of the Face and Neck, From Gould' s Illustrated Medical Dictionary 50 
 
 26. Scheme of Upper Attachments of and Special Names for Deep Cervical Fascia, 51 
 
 27. Thyroid Body, with Middle Lobe and Levator Muscle, 52 
 
 28. Scheme of Superior Thyroid Artery (Coloured}, 53 
 
 29. The Loop Formed by Communicating Branches, After Potter 54 
 
 30. The Muscles Attached to the Back of the Sternum, 54 
 
 31. Vessels and Nerves of Head and Neck, . . . From Gould's Illustrated Medical Dictionary 59 
 
 32. Scheme of the Lingual Artery (Coloured}, 60 
 
 33. Scheme of Occipital and Posterior Auricular Arteries (Coloured}, 61 
 
 34. The Common Carotid, the External and Internal Carotid, and the Subclavian Arteries of the 
 
 Right Side and Their Branches (Coloured}, 62 
 
 35. Anterior and Lateral Cervical Muscles, 64 
 
 36. Scheme for Head and Upper Extremity, After Potter 65 
 
 37. The Subclavian Vessels (Coloured}, 66 
 
 38. The Collateral Circulation after Ligature of the Common Carotid and Subclavian Arteries 
 
 (Coloured}, 67 
 
 39. Scheme of the Superior Intercostal Artery (Coloured}, 68 
 
 40. Scheme of the Vertebral Artery (Coloured}, 69 
 
 41. Scheme of the Cervical Plexus, After Potter 75 
 
 42. Scheme of the Brachial Plexus, After Potter 76 
 
 43. Superficial Branches of the Cervical Plexus (Coloured}, . . . . After Hirschfeld and Leveille 78 
 
 44. Side View of the Tongue with its Muscles, 80 
 
 45- Side of the Face and Mouth Cavity, showing the Three Salivary Glands, 8l 
 
 46. Transverse Section through the Left Half of the Tongue, 82 
 
 47. Scheme of the Right Lingual Artery (Coloured}, Walshatn 83 
 
 48. Side View of the Muscles of the Tongue, 83 
 
 49. The Pterygoid Muscles, 84 
 
 50. Distribution of the Mandibular Division of the Trigeminal Nerve, Henle 84 
 
 51. Scheme of Internal Maxillary Artery (Colotired}, 86 
 
 52. The Temporal Muscle, 88 
 
 53. Scheme of the Distribution of the Fifth Cranial or Trigeminal Nerve, ..... After Potter 89 
 
 54. Muscles, Vessels, and Nerves of the Tongue, 90 
 
 55- The Maxillary Nerve Seen from Without (Colotired} Beaunis 91 
 
 56. The Deeper Layer of the Muscles of the Face and Neck, 94 
 
 57. The Pterygoid Muscles, 95 
 
 58. Temporo-mandibular Articulation. Schematic, 96 
 
 vii 
 
viii LIST OF ILLUSTRATIONS. 
 
 59. Temporo-mandibular Articulation. Schematic, 97 
 
 60. Temporo-mandibular Articulation. Schematic, 97 
 
 61. Distribution of the Pneumogastric Nerve Viewed from Behind (Coloured), .... Krause loo 
 
 62. The Muscles of the Pharynx, . 101 
 
 63. The Muscles of the Pharynx, from Gould's Illustrated Medical Dictionary 102 
 
 64. Median Section of Mouth, Pharynx, and Larynx, 103 
 
 From Gould's Illustrated Medical Dictionary 
 
 65. View of Muscles of Soft Palate, as Seen from Within the Pharynx, . Modified from Bourgery 104 
 
 66. The Muscles of the Front of the Neck 105 
 
 67. Front View of the Cartilages of the Larynx, Modified from Bourgery and Jacob 106 
 
 68. Back View of the Cricoid and Arytenoid Cartilages ( Coloured ), 106 
 
 Modified from Bourgery and Jacob 
 
 69. Posterior View of Thyroid Cartilage with Epiglottis, 107 
 
 70. Front View of the Cricoid and Arytenoid Cartilages (Coloured], 107 
 
 Modified from Bourgery and Jacob 
 
 71. Nerves of the Larynx. (Posterior view.) (Coloured], 108 
 
 72. Side View of the Muscles and Ligaments of the Larynx (Coloured), 109 
 
 73. The Posterior Nares, 112 
 
 74. Section showing Bony and Cartilaginous Septum, 112 
 
 75. Nerves of the Nasal Cavity (Coloured], 113 
 
 76. Transverse Section Passing through the Nasal Fossae and Antra at the Posterior Extremity of 
 
 the Middle Turbinal Bone, 114 
 
 77. Section of the Nose, showing the Turbinal Bones and Meatuses, with the Openings in Dotted 
 
 Outline "5 
 
 78. The Left Maxilla. (Inner view.), 116 
 
 79. The Left Maxilla. (Outer view.), 117 
 
 80. A Section of the Skull, showing the Inner Wall of the Orbit, the Base of the Antrum, and the 
 
 Spheno-maxillary Fossa, 118- 
 
 81. The Skull in Sagittal Section, 121 
 
 82. The Cranium Opened to Show the Falx Cerebri, the Tentorium Cerebelli, and the Places 
 
 where the Cranial Nerves Pierce the Dura Mater (Coloured], Sappey 122 
 
 83. Coronal Section of the Head Passing through the Mastoid Process 123 
 
 84. Schematic, 124 
 
 85. Coronal Section through the Great Longitudinal Fissure, showing the Meninges, 1^5 
 
 Key and Retzius 
 
 86. The Venous Sinuses (Coloured} 127 
 
 87. Schematic, . 129 
 
 88. Relation of the Various Structures Passing through the Cavernous Sinus, 129 
 
 89. Ear and Tympanum, From Gould's Illustrated Medical Dictionary 133 
 
 90. Scheme of Facial Nerve Communicating with Fifth Cranial Nerve, After Potter 134 
 
 91. The Arteries of the Brain (Coloured}, 136 
 
 92. Surface Origin of the Cranial Nerves (Coloured}, After Allen Thomson. Qiiain 
 
 93. Tendo Oculi and Tarsal Cartilages, 14 
 
 94. Relations of the Eye and the Lachrymal Excretory Apparatus, 14 
 
 From Gould's Illustrated Medical Dictionarv 
 
 95. Schematic Representation to Show Relation of Periosteum to Tarsal Cartilages and Tarsal 
 
 Ligaments, I4 1 
 
 96. View of Left Orbit from Above, showing the Ocular Muscles, . From Hirschfeld and Lernlle 142 
 
 97. Muscles of the Eye From Gould's Illustrated Medical Dictionary 142 
 
 98. Nerves of the Orbit, from the Outer Side (Coloured), 143 
 
 From Sappey, after Hirschfeld and Leveille 
 
 99. Left Eyeball Seen in its Normal Position in the Orbit, with View of the Ocular Muscles, . . 144 
 
 After Merkel, modified 
 
 100. Muscles of the Eye. Tendon or Ligament of Zinn, 144 
 
 From Gould's Illustrated Medical Dictionary 
 
 101. Diagrammatic Representation of Origins of Ocular Muscles at the Apex of the Right Orbit, 145 
 
 After Schwalbe, slightly altered 
 
 102. Vertical Section through the Eyeball and Orbit in the Direction of the Orbital Axis, with 
 
 Closed Eyelids (Coloured}, ', . . . After Schwalbe, modified 146 
 
 103. The Ophthalmic Artery and Vein (Coloured) 14 
 
 104. Lachrymal Apparatus, After Schwalbe 147 
 
 105. Superficial Veins and Lymphatics of the Forearm and Arm (Coloured}, 153 
 
 106. Distribution of Cutaneous Nerves on the Anterior and Posterior Aspects of the Superior Ex- 
 
 tremity 154 
 
 107. Diagram of the Great Palmar Bursa, '55 
 
 108. The Left Hand. (Dorsal surface.) (Coloured}, 156 
 
 109. The Left Hand. (Palmar surface.) (Coloured}, 157 
 
 no. The Superficial Muscles of the Palm of the Hand, 158 
 
 111. Superficial Nerves of the Palm (Coloured}, Ellis 159 
 
 112. The Deeper Muscles of the Palm of the Hand, 160 
 
 113. Anastomoses and Distribution of the Arteries of the Hand (Coloured) 161 
 
 114. The Pronator Quad rat us and Deep View of the Palm, 163 
 
 115. The Palmar Interossei, 164 
 
LIST OF ILLUSTRATIONS. ix 
 
 
 
 FK... PAGE 
 
 116. Anastomoses and Distribution of the Arteries of the Hand (Coloured], 165 
 
 117. The Arteries of the Forearm with the Deep Palmar Arch (Coloured'], 172 
 
 118. The Bend of the Elbow with the Superficial Veins (Coloured ), 173 
 
 119. The Brachial Artery at the Bend of the Elbow (Coloured], 174 
 
 120. Front of the Forearm : First Layer of Muscles, 175 
 
 121. Superficial Muscles of Palmar Aspect of Forearm, 176 
 
 From Gould'' 's Illustrated Medical Dictionary 
 
 122. Front of the Forearm : Second Layer of Muscles, 177 
 
 123. The Lower Part of the Axillary, the Brachial, and the Radial and Ulnar Arteries (Coloured}, 178 
 
 124. The Left Ulna and Radius. (Antero-internal view.) (Coloured), 179 
 
 125. Front of the Forearm: Third Layer of Muscles, 180 
 
 126. Superficial View of the Front of the Upper Arm, 181 
 
 127. Deep View of the Front of the Upper Arm, 182 
 
 128. Deep Muscles of Palmar Aspect of Forearm, . From Gould' 's Illustrated 'Medical Dictionary 183 
 
 129. The Left Humerus with a Supracondyloid Process and some Irregular Muscle Attachments. 
 
 (Anterior view.) (Coloured), 184 
 
 130. The Pectoralis Major and Deltoid, 188 
 
 131. The Left Clavicle. (Superior surface.) (Coloured), 188 
 
 132. The Clavi-pectoral Fascia, 189 
 
 133. To Show Schematically the* Distribution of the Deep Cervical Fascia Above and Below the 
 
 Clavicle, 190 
 
 134. The Left Clavicle. (Inferior surface.) (Coloured), 191 
 
 135. Serratus Magnus. The Inner Wall of the Axilla, 192 
 
 136. Front View of the Scapular Muscles. The Posterior Wall of the Axilla, 193 
 
 137. The Lower Part of the Axillary, the Brachial, and the Radial and Ulnar Arteries (Coloured), 194 
 
 138. First and Second Ribs (Coloured), 198 
 
 139. The Sternum, 199 
 
 140. The Intercostal Muscles, 200 
 
 141. The Intercostal Nerves, 201 
 
 142. The Muscles Attached to the Back of the Sternum, 202 
 
 143. Scheme of the Internal Mammary Artery (Coloured), 203 
 
 144. Anterior View of the Lungs: Pericardium, Modified from Bourgery 205 
 
 145. Anterior View of the Thorax with Chest Wall Removed, showing the Lungs, 206 
 
 Modified front Bonrgery 
 
 146. Invagination of Pleura, 207 
 
 147. Thymus Gland in a Child at Birth, 209 
 
 148. Scheme of the Fcetal Circulation, 210 
 
 149. Anterior View of Fcetal Heart, Vessels, and Lungs, 211 
 
 150. The Arch of the Aorta, the Thoracic Aorta, and the Abdominal Aorta, with the Superior and 
 
 Inferior Vena Cava and the Innominate and Azygos Veins (Coloured), 212 
 
 151. The Heart and Great Vessels, with the Root of the Lungs, Seen from Behind (Coloured), . 214 
 
 152. The Sympathetic System of Nerves, After Potter 215 
 
 153. The Arch of the Aorta, with the Pulmonary Artery and Chief Branches of the Aorta 
 
 (Coloured), 217 
 
 154. Anterior View of the Right Chambers of the Heart, with the Great Vessels, 219 
 
 155- I he Heart, with the Arch of the Aorta, the Pulmonary Artery, the Ductus Arteriosus, and 
 
 the Vessels Concerned in the F(etal Circulation (Coloured), 220 
 
 156. Anterior View of the Heart, showing its Arteries and Veins (Coloured), 222 
 
 157. Posterior View of the Heart, showing its Arteries and Veins (Coloured), 223 
 
 158. Cutaneous Nerves of the Thorax and Abdomen, Viewed from the Side, .... After Hcnle 226 
 
 159. External Oblique and Ilio-tibial Band, 227 
 
 160. The Pectoralis Minor, Obliquus Internus, Pyramidalis, and Rectus Abdominis, 228 
 
 161. Obliquus Externus and Fascia Lata, 229 
 
 162. Transversalis Abdominis and Sheath of Rectus, 230 
 
 163. Internal Oblique and Transversalis Abdominis Muscles, 232 
 
 From Gould's Illustrated Medical Dictionary 
 
 164. Dissection of the Lower Part of the Abdominal Wall from Within, the Peritoneum having 
 
 been Removed, , . Wood 235 
 
 165. Irregularities of the Obturator Artery, After Gray 237 
 
 166. Vessels of the Small Intestine, 238 
 
 167. Showing Partial and Complete Investment of Organs by Peritoneum, 239 
 
 168. Showing Retro-peritoneal Locality, 239 
 
 169. Showing Aorta and Primitive Mesentery, 240 
 
 170. Showing Loss of Endothelium at Contact Point of Visceral and Parietal Peritoneum, .... 240 
 
 171. Showing Simple Visceral and Parietal Layers of Peritoneum with Cavity Between Them, . . 241 
 
 172. Diagram of the Primitive Alimentary Canal, 243 
 
 173. Diagrams showing (A) the Formation of the Great Omentum, and (E) the Rotation of the 
 
 Intestinal Canal, 244 
 
 174. The Cceliac Artery and its Branches (Coloured), 247 
 
 175. The Viscera as Seen on Fully Opening the Abdomen without Disarrangement of the Internal 
 
 Parts, After Sarazin 247 
 
 176. The Viscera of the Foetus, Riidinger 249 
 
 177. Relation of Structures at and below the Transverse Fissure, Thane 251 
 
x L/ST OF ILLUSTRATIONS. 
 
 
 
 FIG. ru.K 
 
 178. The Inferior Surface of the Liver, 254 
 
 179. Posterior Surface of the Liver, 254 
 
 180. The Superior Mesenteric Artery and Vein (Coloured ), 257 
 
 181. The Inferior Mesenteric Artery and Vein (Coloured), 258 
 
 182. Diagram showing Anterior Relations of Kidneys and Suprarenal Bodies 259 
 
 183. The Abdominal Aorta and its Branches, with the Inferior Vena Cava and its Tributaries, . . 260 
 
 184. The Sympathetic System of Nerves, After Potter 262 
 
 185. The Sympathetic System of Nerves, After Potter 264 
 
 l8b. Showing Schematically a Sensory Reflex Circuit, 269 
 
 187. Showing Schematically a Motor Reflex Circuit, 270 
 
 188. To Show Relation of Abdominal Sympathetic Nerves to (l) Solar Plexus, and (2) to the 
 
 Ganglion at the Root of the Artery, 271 
 
 189. Lumbar Portion of the Gangliated Cord, with the Solar and Hypogastric Plexuses (Coloured), 272 
 
 (After ilenle) 
 
 190. Branches of the Lumbar and Sacral Plexus, Viewed from Before (Coloured}, 276 
 
 After Hirschfeld and Leveillc 
 
 191. Side View of Pelvis and Upper Third of Thigh, with the External Iliac, Internal Iliac, and 
 
 Femoral Arteries and their Branches (Coloured), 277 
 
 192. Muscles of the Floor of the Pelvis . . 278 
 
 193. Diagram of the Lumbar and Sacral Plexuses, Modified from Paterson 280 
 
 194. A Dissection of the Lumbar and Sacral Plexuses, from Behind (Coloured), 281 
 
 195. Diaphragm, 286 
 
 196. The Left Hip-bone. (Internal surface.) (Coloured), 287 
 
 197. Psoas, Iliacus, and Quadratus Lumborum, 288 
 
 198. Arrangements of Lumbar Aponeurosis at Level of Third Lumbar Vertebra, 289 
 
 199. The Sacrum and Coccyx. (Anterior view.) (Coloured), 290 
 
 200. Muscles of the Floor of the Pelvis, 290 
 
 201. The Broad Ligament and its Contents, seen from the Front, After Sappey 291 
 
 202. Representing Schematically the Relation of the Ureter to the Broad Ligament of the Uterus, 292 
 
 203. Frontal Section of the Virgin Uterus, After Sappey 292 
 
 204. Scheme of the Ovarian and Uterine and Vaginal Arteries (Coloured),- 293 
 
 205. The P'emale Organs of Generation, Modified from Sappey 293 
 
 206. Sagittal Section of the Virgin Uterus, ' After Sappey 294 
 
 207. The Left Tibia and Fibula. (Anterior view.) (Coloured), 300 
 
 208. The Left Tibia and Fibula. (Posterior view.) (Coloured), 301 
 
 209. Distribution of Cutaneous Nerves on the Anterior Aspect of the Inferior Extremity, .... 303 
 
 210. The Superficial Veins and Lymphatics of the Lower Limb (Coloured), 304 
 
 211. Superficial Dissection of the Front of the Thigh, Hirschfeld and Lerei/le 305 
 
 212. The Femoral Ring and Saphenous Opening, After Holden 309 
 
 213. The Muscles of the Front of the Leg, 311 
 
 214. The Anterior Tibial Artery, Dorsal Artery of the Foot, and Anterior Peroneal' Artery, and 
 
 their Branches (Coloured), 312 
 
 215. The Left Foot. (Dorsal surface.) (Coloitred), 313 
 
 216. The Left Tibia and Fibula. (Anterior View.) (Coloured), 314 
 
 217. Branches of the External Popliteal Nerve (Coloured), 3*6 
 
 218. Muscles of the Front of the Thigh, 317 
 
 219. Anterior Crural and Obturator Nerves, 318 
 
 220. The Deep Muscles of the Front of the Thigh, 319 
 
 221. Pectineus and Adductor Longus, 3 2 
 
 222. Adductor Brevis and Adductor Magnus, 320 
 
 223. The Femoral Artery in Scarpa's Triangle (Coloured), 3 22 
 
 224. Obliquus Externus and Fascia Lata, 323 
 
 225. Muscles of the Anterior Aspect of the Body, . From Gould 1 s Illusti ated Medical Dictionary 324 
 
 226. The Left Hip-bone. (Posterior view.) (Coloured) 325 
 
 227. The Left Femur. (Posterior view.) (Coloured), 326 
 
 228. The Left Femur. (Anterior view.) (Coloured), 327 
 
 229. The Male Perineum (Coloured), Modified from Hirschfeld unif Lcreill,'- 331 
 
 230. The Arteries of the Perineum (Coloured), 332 
 
 231. Transverse Section through the Body of the Penis (Coloured), 333 
 
 232. The Male Urethra, cleft dorsally t<> Show Ventral Mucous Wall, .... 335 
 
 233. Diagram of the Superficial and 1 )eep Triangular Ligaments (Coloured), 330 
 
 234. Muscle of Guthrie 3.^7 
 
 235. Muscle of Guthrie and Wilson, 337 
 
 236. V:isa I h-feientia and Vesiculae Seminales, (fter Sappey 338 
 
 237. Diagrammatic Representation of the Peiineal Structures in the Female 341 
 
 238. External Genitals of the Virgin, with Diaphragmatic Hymen, -{flcr Sappey 342 
 
 239. Sri lion of the Female Pelvis, ... After Henle 343 
 
 240. The Left Scapula. (Dorsal surface.) (Coloured), 345 
 
 241. Distribution of Cutaneous Nerves on the Anterior and Posterior Aspects of the Superior Y.\ 
 
 tremity, 34^ 
 
 242. A Dissection of the Cutaneous Nerves on the Dorsal Aspect of the Hand and Fingers 
 
 H.St.J.B. 347 
 
 243. Muscles of the Radial Side and the Back of the Forearm 349 
 
LIST OF ILLUSTRATIONS, xi 
 
 FIG. PAGE 
 
 244. Tendons upon the Dorsum of the Hand, 350 
 
 245. The Deep Layer of the Back of the Forearm, 351 
 
 246. The Left Ulna and Radius. (Postero-external view.) (Coloured), 352 
 
 247. The Back of the Forearm, with the Posterior Interosseous Artery and Branches of the Radial 
 
 at the Back of the Wrist (Coloured), 353 
 
 248. The Dorsal Interossei, 354 
 
 249. The Posterior Circumflex Artery (Coloured), 356 
 
 250. First Layer of the Muscles of the Back, 357 
 
 251. Back View of the Scapular Muscles and Triceps, 358 
 
 252. Posterior View of the Shoulder-joint, showing also the Acromio-clavicular Joint and the Proper 
 
 Ligaments of the Scapula, 359 
 
 253. Triceps Brachialis, Posterior Aspect, from Gould's Illustrated Medical Dictionary 360 
 
 254. The Dorsal Scapular Artery (Coloured), 361 
 
 255. Distribution of Cutaneous Nerves on the Posterior Aspect of the Inferior Extremity 367 
 
 256. Superficial Muscles of the Back of the Thigh and Leg, 368 
 
 257. Gluteus Maximus Muscle, From Gould ' s Illustratea Medical Dictionary 370 
 
 258. A Dissection of the Nerves in the Gluteal Region (Coloured), 371 
 
 259. The External Rotators and the Hamstring Muscles, 373 
 
 260. Deep Dissection of the Gluteal Region, 374 
 
 261. Horizontal Section of the Knee-joint. (One-half.), 375 
 
 262. Short Head of Biceps and Semimembranosus, . From Gould's Illustrated Medical Dictionary 376 
 
 263. Long Head of Biceps and Semitendinosus, . . From Gould's Illustrated Medical Dictionary 376 
 
 264. Deep View of the Popliteal Space, Hirschfeld and Leveille 378 
 
 265. The Deep Muscles of the Hack of the Leg 379 
 
 266. Relations of the Popliteal Artery to Bones and Muscles (Coloured,) 380 
 
 267. The Left Tibia and Fibula. (Posterior view.) (Coloured), 381 
 
 268. The Left Foot. (Plantar surface.) (Coloured), 382 
 
 269. Muscles of the Leg, External Aspect, .... Front Gould's Illustrated Medical Dictionary 383 
 
 270. Second Layer of the Muscles of the Sole, 385 
 
 271. First Layer of the Muscles of the Sole, 386 
 
 272. Superficial Nerves in the Sole of the Foot (Coloured), Ellis 387 
 
 273. The Plantar Arteries (Coloured), 388 
 
 274. Third Layer of the Muscles of the Sole, 389 
 
 275. Fourth Layer of the Muscles of the Sole, 591 
 
 276. Horizontal Section through the Intervertebral Disc and Ribs, 396 
 
 277. Showing the Anterior Common Ligament of the Spine, and the Connection of the Ribs with 
 
 the Vertebne, 396 
 
 278. The Occipital. (External view.) (Coloured), 397 
 
 279. Distribution of the Posterior Primary Divisions of the Spinal Nerves, .... 399 
 
 280. First Layer of Muscles of the Back, 401 
 
 281. The Levator Anguli Scapulas and Rhomboidei, 402 
 
 282. The Third and Fourth Layers of the Muscles of the Back, ... 403 
 
 283. The Fifth Layer of the Muscles of the Back, 404 
 
 284. The Fifth Layer of the Muscles of the Back, after Separating the Outer and Middle Divisions, 406 
 
 285. The Sixth Layer of the Muscles of the Back, 408 
 
 286. First Cranial Nerve, Olfactory Afttr Potter 412 
 
 287. Second Cranial Nerve, Optic, ..',...... After Potter 412 
 
 288. Third Cranial Nerve, Motor Oculi, After Potter 413 
 
 289. Fourth Cranial Nerve, Trochlear, After Potter 413 
 
 290. Fifth Cranial Nerve After Potter 414 
 
 291. Seventh Cranial Nerve, Facial, or Portia Dura, After Potter 415 
 
 292. Box Illustration of Seventh Cranial Nerve in Relation to the Middle Ear or Tympanum, . . 416 
 
 293. Eighth Pair of Cranial Nerves, After Potter 418 
 
 294. Vertical Section through the Condyle of Jaw to Show the Two Synovial Sacs and the Inter- 
 
 articular Fibro-cartilage, . 425 
 
 295. External View of Temporo mandibular Joint, 427 
 
 296. Internal View of Temporo-mandibular Joint, 427 
 
 297. Outer View of the Shoulder-joint, showing the Coraco-humeral and Transverse Humeral 
 
 Ligaments, 428 
 
 298. Posterior View of the Shoulder-joint, showing also the Acromio-clavicular Joint and the 
 
 Proper Ligaments of the Scapula, 429 
 
 299. Anterior View of Shoulder, showing also Coraco-clavicular and Coraco-acromial Ligaments, 430 
 
 300. Anterior View of Sterno-clavicular Joint, 431 
 
 301. Orbicular Ligament, 433 
 
 302. External View of the Elbow-joint, 433 
 
 303. Internal View of the Elbow-joint, 434 
 
 304. Anterior View of Wrist, 434 
 
 305. Posterior View of Wrist 435 
 
 306. Synovial Membranes of Wrist, Hnnd, and Fingers, 436 
 
 307. Posterior View of the Capsule of the Hip-joint, 438 
 
 308. Anterior View of the Capsule of the Hip-joint, 439 
 
 309. Hip-joint after Dividing the Capsular Ligament and Disarticulating the Femur, 441 
 
 310. Anterior View of the Internal Ligaments of the Knee-joint, 441 
 
xii LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 311. Posterior View of the Knee-joint, 442 
 
 312. Structures Lying on the Head of the Tibia. (Right knee.), 442 
 
 313. Anterior View of the Knee-joint, showing the Synovial Ligaments, 443 
 
 314. The Left Foot. (Plantar surface.) (Coloured), 446 
 
 315. The Left Foot. ( Dorsal surface. ) (Coloured), 447 
 
 316. Section to Show^ the Synovial Cavities of the Foot, 448 
 
 317. External View of the Ligaments of the Foot and Ankle, 449 
 
 318. Inner View of the Ankle and the Tarsus, showing the Groove for the Tendon of the Tibialis 
 
 Posticus, 450 
 
 319. Ligaments of the Sole of the Left Foot, 450 
 
 320. Ligaments seen from the Back of the Ankle-joint, 452 
 
 321. Right Innominate Bone, External Aspect, . .From Gould 's Illustrated Medical Dictionary 453 
 
 322. Pelvis, Antero-superior View, Superior Strait, . From Gould 's Illustrated Medical Dictionary 453 
 
 323. Femur, Posterior Aspect, From Gould'' s Illustrated Medical Dictionary 454 
 
 324. Anterior View of the Symphysis Pubis (Female, showing Greater Width between the Bones), 455 
 
 325. Posterior View of the Symphysis Pubis, showing the Backward Projection of the Symphysial 
 
 Substance and the Decussation of the Fibres from the Inferior Pubic Ligament, 455 
 
 326. Anterior View of the Symphysis Pubis (Male) showing Decussation of the Fibres of the 
 
 Anterior Ligament, 455 
 
 327. Anterior View of the Pelvis, 456 
 
 328. Sacro-sciatic Ligaments. (Posterior view.), 457 
 
 329. Vertical Antero-posterior Section of the Pelvis, 458 
 
 330. Coccyx, Anterior Aspect, From Gould' 1 s Illustrated Medical Dictionarv 459 
 
 331. Vertebral Column, Lateral Aspect, From Gould's Illustrated Medical Dictionary 459 
 
 332. Posterior Common Ligament of the Spine. (Thoracic region.), 460 
 
 333- Ligamenta Subflava in the Lumbar Region, 461 
 
 334. Morphology of the Transverse and Articular Processes, 462 
 
 335. The Interspinous and Supraspinous Ligaments in the Lumbar Region, 463 
 
 336. Vertical Transverse Section of the Spinal Column and the Occipital Bone to Show Ligaments, 464 
 
 337. Seventh Cervical Vertebra, Postero- superior View ; Dorsal Vertebra, Antero-superior View ; 
 
 First Dorsal Vertebra, Lateral View ; Eleventh Dorsal Vertebra, Lateral View ; Twelfth 
 
 Dorsal Vertebra, Lateral View, From Gould' 1 s Illustrated Medical Dictionary 465 
 
 338. Occipital Bone, Postero-inferior View, . . . . From Gould' 1 s Illustrated Medical Dictionary 465 
 
 339. Anterior View of the Upper End of the Spine, 466 
 
 340. Showing the Anterior Common Ligament of the Spine, and the Connection of the Ribs with 
 
 the Vertebrae 466 
 
 341. Vertical Antero-posterior Section of Spinal Column through Median Line, showing Ligaments, 467 
 
 342. The Superficial Layer of the Posterior Common Vertebral Ligament has been Removed to 
 
 Show its Deep or Short Fibres, 468 
 
 343. Ribs of Left Side, Posterior Aspect, From Gould 's Illustrated Medical Dictionary 469 
 
 344. Thorax, Anterior View, From Gould's Illustrated Medical Dictionary 469 
 
 345. The Capsular Ligaments of the Costo-vertebral Joints, 470 
 
 346. Horizontal Section through the Intervertebral Disc and Ribs, 471 
 
 347. The Sternum, 47 2 
 
PRACTICAL ANATOMY. 
 
 FUNDAMENTAL PRINCIPLES OF ANATOMY. 
 
 In the following introductory pages will be found some rules and observations 
 on anatomical study which the student must learn, if he would become master 
 of dissecting-room technique. Under the above heading are considered : 
 
 1. Anatomical nomenclature. 
 
 2. Anatomical tissues applied. 
 
 3. Functions of periosteum. 
 
 4. Eminences and depressions of bone. 
 
 5. Anatomical weak points. 
 
 6. Anatomical visceral roots. 
 
 7. Anatomical antagonism in muscles and nerves. 
 
 8. Shape of muscle an index to the nerve-supply. 
 
 9. Hilton's law regarding articular nerves. 
 
 10. Non-apposition of anatomical structures. 
 
 1 1. Anatomical sheaths ; rationale of their formation. 
 
 12. Dissection defined. 
 
 13. Fanciful names for muscles. 
 
 14. Sphincters and orbiculars distinguished. 
 
 15. Geometrical usage in anatomy. 
 
 1 6. Substantive adjectives : use of. 
 
 17. Law of projectiles : its application to grooves. 
 
 1 8. Application of law of projectiles to reflex pain. 
 
 19. Fasciae, superficial and deep. 
 
 20. Aponeuroses : varieties of. 
 
 21. Origin and insertion of muscle. 
 
 22. Synovial membranes. 
 
 23. Serous and mucous membranes. 
 
 24. Anatomical fibrous arches. 
 
 ANATOMICAL NOMENCLATURE. 
 
 This chapter is intended to explain in advance some of the features of 
 anatomical nomenclature, a knowledge of which will facilitate an understanding 
 of what is seen, read, and heard. 
 
 Anatomical nomenclature is the technical language of anatomy. Chemistry, 
 music, law, all the arts and sciences, have their nomenclature. One of the 
 surest indications of thorough system in any science is the nomenclature of that 
 science, if, indeed, a department can be called scientific without a nomenclature. 
 
 9 
 
io PRACTICAL ANATOMY. 
 
 Compound words are used to express the collective sense arising from 
 anatomical union, conjunction, and relation. Words of this class are met many 
 times daily, not only in anatomy, but in every branch of the medical sciences. 
 Sterno-hyoid, omo-hyoid, musculo-aponeurotic, temporo-mandibular, express 
 relations in anatomy that are thoroughly understood by the physician. 
 
 The principle in compound words is clearly in the nature of a copartner- 
 ship. In the expression, radio-ulnar articulation, radius and ulna are both 
 concerned in the formation of this joint ; each bone has an anatomical interest in 
 the joint, hence a physiological responsibility. The name of an articulation, 
 then, to represent fully the copartnership, must include all the parties to 
 the contract. The number of partners must be two ; it may be any number : 
 (i) Sterno-cleido-mastoid ; (2)fronto-malo-spheno-ethmo-lachrymo-maxillo-nasal 
 articulation. 
 
 RULE FOR WRITING MINIMAL COMPOUND WORDS. Place the shorter word 
 first in the ablative, o ; the larger word second, in some euphonious adjective ; 
 connect the two words by a hyphen. The rule for writing maximal compound 
 words is the same. Here the shortest word is placed first ; it and all succeeding 
 words end in o except the last. 
 
 Exceptions to the rule are (i) to indicate direction of motion ; (2) to conform 
 to national or individual ideas of euphony. We may express the direction taken 
 by a missile passing from the radial to the ulnar side thus : radio-ulnarly, or the 
 opposite by ulno-radially. In many cases euphony demands the larger word 
 first. Where exceptions are as important as these, they seem to acquire the 
 dignity of law ; hence remember in writing compound words either word may 
 be placed first. 
 
 Anatomical Opposites in Location or Function. The fundamental idea in 
 each is antagonism ; of location in the former, of function in the latter. An under- 
 standing of one opposite implies the necessity of the other's presence : anterior 
 surface of the scapula is positive evidence of the existence of a posterior surface 
 of the scapula. The principle is sometimes abused e. g., internal iliac muscle is 
 referred to in some texts ; there is no external iliac muscle ; etc. These redun- 
 dancies, while undesirable, since they are misleading, are nevertheless tolerated 
 in some good works on anatomy by a sort of license that characterizes the 
 unique redundancy in legal and scientific phraseology. Musculus flexor carpi 
 radialis and musculus extensor carpi radialis are anatomical examples of ana- 
 tomical structures opposite in function. Remember, too, that structures opposite 
 in function are usually also opposites in point of location on the part of the 
 body in which found. 
 
 EXAMPLES OF COMMON OPPOSITES. 
 
 Superior extremity. Inferior extremity. 
 
 Anterior surface. Posterior surface. 
 
 Ventral mesentery. Dorsal mesentery. 
 
 Central organ. Peripheral organ. 
 
 Somatic nerves. Sympathetic nerve?. 
 
 Proximal end. Distal end. 
 
 Tendinous origin. Tendinous insertion. 
 
 Flexor muscles. Extensor muscles. 
 
 Pronator agents. Supinator agents. 
 
 Greater trochanter. Lesser trochanter. 
 
 Base of lung. Apex of lung. 
 
 Levator muscle. Depressor muscle. 
 
 Gluteus maximus. Gluteus minimus. 
 
 Pectoralis major. Pectoralis minor. 
 
 Peroneus longus. Peroneus brevis. 
 
 Colica dextra. Colica sinistra. 
 
 Centripetal vessels. Centrifugal vessels. 
 
 Compact tissue. Cancellous tissue. 
 
 Longitudinal axis. Transverse axis. 
 
FUNDAMENTAL PRINCIPLES OF ANA TOMY. 
 
 1 1 
 
 CLASSICAL WORDS IN COMMON USE IN ANATOMY. 
 
 A'anu'. Gen. Sing. Plural. Gen. Plural. English. 
 
 Fascia, ... se, .... Fasciae. Fasciarum. Sash. 
 
 Glandula, . . ae, . . . . Glandulas. Glandularum. Gland. 
 
 Vena, . . . ae Venae. Venarum. Vein. 
 
 Artena, . . . ae Arteriae. Arteriarum. Artery. 
 
 Cartilage, . . inis, . . . Cartilagines. Cartilaginum. Cartilage. 
 
 Chondrum, . i, .... Chondra. Chondrium. Cartilage. 
 
 Tendo, ... is, .... Tendines. Tendinium. Tendon. 
 
 Musculus, . i Musculi. Musculorum. Muscle. 
 
 Nervus, . . i Nervi. Nervorum. Nerve. 
 
 Vas is, .... Vasa. Vasorum. Vessel. 
 
 Os, sis, . . . Ossa. Ossium. Bone. 
 
 Os ris, . . . Ores. Orium. Mouth. 
 
 Aponeurosis, is, .... Aponeuroses. Aponeurosium. Band. 
 
 Costa, ... ae, .... Costae. Costarum. Rib. 
 
 Viscus, ... us, ... Viscera. Organ. 
 
 Pons, . . . tis, . . . Pontes. Pentium. Bridge. 
 
 Trochlea, . . ae Trochleae. Trocharum. Pulley. 
 
 Gaster, Stomach. 
 
 Intestinum, . i Intestini. Intestinorum. Intestine. 
 
 Many adjectives are in use, as magnus, longus, brevis, latus, profundus, sub- 
 limis, orbicularis ; they are declined and used as the nature of the case would 
 indicate. 
 
 Rationale of Naming of Certain Muscles. It is important that the student 
 should, early in his course of dissection, understand why certain muscles are 
 named as they are named in the books. In fact, the student should have a 
 knowledge of the principle involved in this part of the nomenclature. To one 
 unfamiliar with this principle the names tibialis antictts, pronator quadratics, 
 extensor minimi, may seem perfect and complete designations. The impression, 
 however, is erroneous, as the above terms are incomplete. In other words, the 
 terms above given are only abbreviations, and are properly used when the 
 manner by which usage sanctions them is understood. The principle is this : 
 The complete technical name of a muscle contemplates : (i) The structure ; (2) the 
 structure in the capacity of an agent ; (3) an agent of something ; (4) an agent 
 adjectively qualified in such a manner as to distinguish it from others of a syner- 
 gistic class. 
 
 STRUCTURE. AGENT. AGENT OF WHAT. DESCRIPTIVE ADJECTIVES. 
 
 Mttsculus 
 
 flexor 
 
 carpi 
 
 Musculus 
 
 flexor 
 
 carpi 
 
 Musculus 
 
 flexor 
 
 cubiti 
 
 Musculus 
 
 extensor 
 
 carpi 
 
 Musculus 
 
 extensor 
 
 carpi 
 
 Musculus 
 
 extensor 
 
 digitorum 
 
 Musculus 
 
 extensor 
 
 digiti 
 
 Musculus 
 
 levator 
 
 labii 
 
 radialis 
 
 ulnaris 
 
 bicipitalis 
 
 radialis 
 
 radialis 
 
 communis 
 
 minimi 
 
 superioris 
 
 longior 
 brevior 
 
 We unconsciously acquire a habit of using the abbreviated name, and this 
 explains in part the lamentable fact that so many students leave school with a 
 memory well stored with words words numerous, ponderous, classical words 
 which, by virtue of their abbreviational arrangement, leave on the memory no 
 notion of the physiological function of the muscle. At times the habit of thinking 
 of names of muscles almost makes us fail to recognize the full name. The 
 following table will illustrate this point : 
 
 ANATOMICAL NAME. 
 
 TECHNICAL NAME. 
 
 Tibialis anticus Musculus flexor tarsi tibialis anticus. 
 
 Tibialis posticus Musculus extensor tarsi tibialis posticus. 
 
 Peroneus longus Musculus extensor tarsi peroneus longus. 
 
12 PRACTICAL ANATOMY. 
 
 ANATOMICAL NAME. TECHNICAL NAME. 
 
 Peroneus brevis, Musculus extensor tarsi peroneus brevis. 
 
 Peroneus tertius Musculus flexor tarsi peroneus tertius. 
 
 Triceps, . . . ' Musculus extensor cubiti tricipitalis. 
 
 Biceps, Musculus flexor cubiti bicipitalis. 
 
 Supinator longus Musculus supinator brachio-radialis longior. 
 
 Supinator brevis Musculus supinator brachio-radialis brevior. 
 
 Pronator quadratus, Musculus pronator radii quadratus. 
 
 Grammatical Xotc. In constructing technical names of muscles, note (i) the 
 agent, and (2) the descriptive adjectives are in apposition with musculus. The 
 thing or part of which another part is the agent is in the genitive case. The 
 student will note that adjectives are mainly of the first and second declensions, 
 some of the third ; sublimis belongs to the third, so do not write it sublimits. 
 
 TECHNICAL USE OF PREPOSITIONS. 
 
 An almost unlimited number of words designative of relation are formed by the 
 judicious use of classical prepositions. It will be noted that these words, while 
 governing case in the language from which they are taken, cease to be 
 prepositional in anatomical nomenclature in the great majority of instances. 
 Still they may be so used; and upon the distinction now about to be made depends 
 the proper construction of the new words which come into being by thousands 
 by the simple process of incorporating classical prepositions. In the following 
 cases the words are used prepositionally, and written thus : 
 
 1. Iter e tertio ad quartum ventriculum. 
 
 2. Processus e cerebello ad testes. 
 
 3. Portio inter duram et mollem. 
 
 4. Musculus accessorius ad flexorem, etc. 
 
 5. Musculus accessorius ad musculum, etc. 
 
 In the majority of cases the word is absorbed to form a new word, bearing a 
 close relation in location, and not in structure ; to the word into which it was incor- 
 porated. The following examples will illustrate the process of forming new- 
 words and their proper writing : Subcostal, intermaxillary, infraorbital, supra- 
 orbital, intraabdominal, extrauterine. Remember, then, this rule for writing 
 these words : Where they are prepositionally used, the preposition governs the 
 accusative ; where they are used in a corporate capacity, the preposition and the 
 qualified word, or its adjective representative, are written as one word. 
 
 Inter is used to express relation between anatomical structures having the 
 same name. Not only does it express relation in this sense, but it also names 
 every structure in the locality : Intercostal space, muscle, fasciae, vessels, and 
 nerves. 
 
 Intra as intrauterine, intrapelvic, intracranial, intrathoracic, intraabdominal, 
 intratympanic, intramural, intraintestinal, intramuscular, means inside of or in 
 the substance of. Its verbal opposite is extra. 
 
 Sub implies location under, in the sense of occupying a deeper plane : Sub- 
 cutaneous, subserous, submucous, subperitoneal, subpleural, subsynovial, subcon- 
 junctival. It has no opposite, none being necessary to make descriptions of this 
 nature more definite. Its legitimate field of usefulness in our nomenclature 
 seems to be in expressing relations in the concrete rather than in the abstract. 
 Submucous means a territory under all mucous membrane ; subcutaneous, under 
 the skin everywhere, regardless of location of skin or kind of animal. How 
 such expressions as submuscular, subosseous, or subgastric would shock our 
 conception of the proper use of this word ! Still, such barbarisms as sub- 
 maxillary, submcntal, and sublingual are sanctioned by usage and good usage, 
 too. 
 
FUNDAMENTAL PRINCIPLES OF ANATOMY. 13 
 
 Supra is limited in its application to a few areas, for the reason that it does 
 not combine well to form euphonious words, and euphony, you will observe, is 
 a potent factor in determining the volume of our anatomical vocabulary. The 
 chief use of the term is in physical diagnosis, where regions requiring no definite 
 limitations are indicated by supra in combination with the name of the locality 
 under consideration : Supraorbital, suprasternal, supraclavicular, suprascapular, 
 suprapubic, supratrochlear, supratrochanteric, supracondylar, supragluteal, supra- 
 hyoid, supraacetabular. Infra is the opposite, but can not with propriety be used 
 in some cases, as infracondylar ridge, since no such ridge exists. 
 
 Juxta has the specific meaning of one above another with parallelism of 
 parts. Its use is confined to osteology almost wholly, with no good reason. In 
 the vertebral column we have juxtaposition of bodies, transverse, spinous, and 
 articular processes ; juxtaposition of laminae, pedicles, and intervertebral notches. 
 Still, for practical purposes, the biceps and brachialis are in juxtaposition. Usage 
 determines the scope of legitimate nomenclature. 
 
 Pre, as in preaxial, the opposite of post-axial ; in presystolic ; in pre- 
 vertebral, in speaking of the three great prevertebral gangliated plexuses of the 
 sympathetic nervous system. The use of this word is limited. 
 
 Peri. The prepositional excellence of anatomical nomenclature seems to 
 culminate in the word now under consideration. For this there is good reason : 
 its euphonious nature combines with everything of an anatomical kind, either 
 in substantive or adjective form, and besides it expresses a relation comprehending 
 all other relations around. Every visible anatomical structure possesses a 
 protective coat or sheath, which surrounds and protects the same. Many of 
 these are expressed by peri in combination, as the following will show : Peri- 
 osteum, perimysium, periuterine, pericardium, peritendineum, peridontium, peri- 
 pulmonum, perichondrium, perineurium, peritoneum, perinaeum, periglottis, 
 periorbita, perivenal, periproctic, peristaltic, perivisceral. 
 
 In the course of your dissection make a study of each technical word used, 
 and you will soon acquire a habit of thinking in anatomical terms when doing 
 anatomical work. Remember every anatomical region is occupied by structures, 
 and these structures have names and relations. If you learn the principles on 
 which the technical language of anatomy is founded, then you shall have passed 
 the first milestone on your way to a medical education.* 
 
 THE ANATOMICAL TISSUES. 
 
 In the dissecting-room you meet normal tissues, as muscle, nerve, and skin, 
 in all their various forms and combinations. It is here you should apply 
 practically those things you have learned in such thorough detail in the histo- 
 logical laboratory. It is true you deal here with these tissues, not with the 
 microscope, but with the unaided eye and the sense of touch. In the laboratory 
 you learned to recognize epithelial tissue in general and special, and you classified 
 the same according to the shape and strata of the cell. Here it is enough for 
 you to remember that the epithelial tissues cover the free surface of the skin and 
 mucous membrane. 
 
 The Bulky Portion of Your Work is Made Up of Muscles. Of these you 
 learn origin, insertion, relation, nerve-supply, blood-supply, investment, and func- 
 tion. This is gross anatomy. You must also remember histologically that 
 all muscles belong' to the muscular tissues, that the characteristic of these tissues is 
 
 *The technical terms used in anatomy are chiefly of Latin derivation ; the grammatical construction 
 is purely so. In view of the importance of being familiar with our nomenclature, I would recommend 
 Robinson's Latin Grammar, both for those who have given but little lime to classical study and also for 
 those who wish to review the same. 
 
14 PRACTICAL ANATOMY. 
 
 contractility, and that muscles occur, (i) in the voluntary form ; (2) the involuntary 
 form. You will be expected to classify each muscle according to the above 
 forms. To aid you in this, the following table is inserted : 
 
 TABLE SHOWING WHERE INVOLUNTARY MUSCLES ARE FOUND. 
 
 Character of fibre : Smooth, non-striated. 
 
 1. In the alimentary canal (oesophagus, stomach, intestines, large and small), and 
 
 in the embryological offspring of the duodenum (the common bile duct, the 
 hepatic ducts, the gall-bladder, and the pancreatic duct) and salivary glands. 
 
 2. In the genito-urinary tract of the male and female: the muscular part of the 
 
 vas, the seminal vesicles, Cowper's glands, the corpora spongiosa and 
 cavernosa, and the prostate in the male ; in the uterus, vagina, Fallopian 
 tubes, round and broad ligaments, and in the erectile tissue of the nipple 
 and external genitals of the female. In the bladder, urethra, and all parts 
 of the urethra in botJi male and female. 
 
 3. In the trachea, bronchi, and pleura ; in all arteries, veins, and lymphatics ; 
 
 in the iris, ciliary body, and eyelids ; in the skin of the scrotum ; in the 
 hair follicles and sebaceous glands. 
 
 4. You will see later that the territory where you are to locate the involuntary 
 
 form of muscular tissue coincides with the distribution of the sympathetic 
 nerve, or the nerve of organic life. 
 
 You Will Find Brain and Nerves. The structural part of these is purely 
 histological ; still, you will be expected to remember that nerve-tissue consists of 
 cells, fibres, and neuroglia, and a connective-tissue framework. You will find 
 nerves, called sympathetic^ supplying the viscera and all others ; the ccrcbro-spinal, 
 supplying the skin, joints, muscles, and organs of special sense. You sJiould 
 remember that all brain and nerve matter belong to the nervous tissues. 
 
 The connective tissues, in their many forms, will be found everywhere. I 
 wish thus, in advance, to teach you where to find and how to classify the same. 
 All the peristructures mentioned in the chapter on nomenclature are forms of 
 connective tissue. This is the most widely distributed of all the tissues. Your 
 task now is to learn to recognize its forms as you meet them. 
 
 FORMS OF CONNECTIVE TISSUE You WILL MEET IN THE DISSECTING-ROOM. 
 
 1. Mucous Form. This is a clear, jelly-like substance surrounding the umbilical 
 
 cord. Ligate this and see how easily a thread cuts through the same. 
 This is the jelly of Wharton you will hear about. // is one form of con- 
 nective tissue. 
 
 2. Areolar Form. Immediately on removing the skin you will notice the areolar 
 
 form of connective tissue. It is also called superficial fascia in this 
 locality. It contains a variable amount of fat.. It is called areolar mem- 
 brane in some of the older text-books. On separating one muscle from 
 another, you will see this areolar tissue. Its specific name, in this locality, 
 is intermuscular fascia. 
 
 3. Cartilage forms of connective tissue occur in the trachea, larynx, and external 
 
 ear, where the presence of this tissue gives these structures their strength 
 and elasticity. You will find it completing the space between the ribs and 
 sternum ; you will find it covering the articular surfaces of bone in 
 movable joints. 
 
 4. Bone l ; onn. This is coextensive with the osseous skeleton. Every bone, be 
 
 it long, short, flat, irregular, is connective tissue in this form. Each bone 
 is covered, at its articular surface, when it moves upon another bone, by 
 
FUNDAMENTAL PRINCIPLES OF ANATOMY. 15 
 
 cartilage : this cartilage is one form of connective tissue. Each bone is 
 covered by periosteum, except at the articular surfaces ; this periosteum 
 is connective tissue. 
 
 5. Elastic Form. In the interlaminar ligaments, or ligamenta subflava, you will 
 
 find a form of connective tissue, yellowish in color, and also dense, elastic, 
 and strong. You will find this as well in the epiglottis. Wherever you 
 find structures possessing (i) elasticity, (2) yellowisJi color, as the aorta and 
 structures above mentioned, they owe these qualities to the elastic form 
 of connective tissue. 
 
 6. Adipose Form. You will find this in the superficial fascia or areolar tissue 
 
 under the skin ; in the great omentum, about the heart, in the iliac region 
 of the pelvis, and in the ischio-rectal fossa. Remember, fat is the adipose 
 form of connective tissue. This tissue represents the great storehouse 
 for potential energy. The student who desires to see the human body 
 in possession of this potential energy will select a fat subject for dissec- 
 tion ; while the student who desires to keep his hands clean will continue 
 to clamor for lean material. If you intend to do surgical operations, 
 remember this : The emaciated patient is seldom operated on. Only 
 those possessing fat and vitality are considered good risks. If you dissect 
 a fat cadaver, then you may expect to see man as he is in health. A lean 
 man is man minus fat not a fair sample. 
 
 7. Supporting Form. Dissect any organ, and you will find it covered by a layer 
 
 of connective tissue, and the parts making up the interior supported by 
 the same. Boil a muscle, and you will see the connective tissue interior. 
 Macerate thoroughly a spleen, and by gentle compression in warm water 
 remove the spleen-pulp, and you will have remaining the connective tisstie 
 of this organ the supporting form of connective tissue. The nerve-cells and 
 nerve-fibres are likewise supported by connective tissue, called neuroglia. 
 
 8. Dense Form. This form you will find in tendons and fasciae ; in the cornea 
 
 and sclera ; in the dense aponeuroses ; in the strong intermuscular septa. 
 
 QUERY. How can a tissue appear in so many forms ? How is it possible to 
 recognize in the dentine of the teeth and in the areolar tissue between muscles one 
 and the same tissue ? How can you classify bone and the jelly of Wharton in 
 the same category ? 
 
 EXPLANATION. Each tissue consists of two constituents: (i) Cells, (2) inter- 
 cellular substances. The former are products of the ovum ; the latter of the cells 
 themselves. Each constituent has a certain part to perform in the organ in which 
 the tissue is found. Upon the cell depends the life of the tissue ; upon the inter- 
 cellular substance depend the jelly-like condition, the dentine hardness, the fascial 
 strength, the areolae of intermuscular connective tissue and superficial fascia, the 
 resistance of muscle, the elasticity of the ligamentum subflavum, the cement sub- 
 stance of the epithelial tissues covering the surfaces of the integument and the 
 various mucous membranes. 
 
 Homely illustration of how a tissue can appear under so many different forms 
 and still remain connective tissue : (i) Permit water to represent the intercellular 
 substance ; (2) permit plastcr-of -Paris to represent the cellular element. As you 
 mix the two, the water will become more and more condensed, until you have 
 finally obtained a substance of bony hardness. The plaster remains plaster, 
 having undergone no changes. In the tissue under consideration the cellular 
 element remains the same : The bone-cell is morphologically the same as the 
 jelly-cell, the tendon-cell, and the fascia-cell. Condensation of the intercellular 
 substance is when the changes have really taken place. 
 
 In your dissections, when you find fascia, tendon, bone, cartilage, sclera, 
 
i6 
 
 PR A CTICAL ANA TOM \ '. 
 
 cornea, peristructures, supporting structures, dentine, and Wharton's jelly, you 
 are to remember, these structures, while widely varying in form, all belong to 
 the greater connective tissue family. 
 
 RESUME OF ANATOMICAL TISSUES. 
 
 1. Muscular tissue, for voluntary and involuntary contraction, upon which 
 
 depend the aggressive and defensive attitudes of the body, as well as 
 the movements of hollow conduits and certain viscera. 
 
 2. Nervous tissue, upon which depends intellection, reception of impression from 
 
 an environment, and transmission of brain impulses, whether voluntary 
 or involuntary. 
 
 3. Connective tissue, on which depends strength, framework, and various invest- 
 
 ing structures. Common forms specialized are tendon, ligament, capsule, 
 bone, cartilage, dentine, cementum, etc. 
 
 4. Epithelial tissue, upon which depend external and internal protection, giving 
 
 as these tissues do a certain resiliency and stability to the areas which 
 they cover, as the skin and mucous membranes. 
 
 /$W ofcompressed 
 cotfon reareseafint 
 
 sheath. 
 
 Nerve 
 
 Artery 
 
 Vein 
 
 FIG. i. DISPLACEMENT OF COTTON BY GROW- 
 ING PLANTS. 
 
 Meuro venous septum 
 Neuro arterial septum- . 
 
 FIG. 2. CONNECTIVE TISSUE DISPLACED BY 
 THE ARTERY, NERVE, AND VEIN; THE 
 CONNECTIVE TISSUE LEFT BETWEEN THE 
 ARTERY AND NERVE AND BETWEEN THE 
 NERVE AND VEIN ARE Two SEPTA. 
 
 Rationale of the formation of anatomical sheaths, tunics, togas, cap- 
 sules, and all the peristructures referred to and enumerated in the section on 
 anatomical nomenclature. 
 
 In your dissections you will meet the capsules of glands and the sheaths of 
 vessels. Where an artery, vein, and nerve are in the same sheath, they will be 
 separated from each other by a. septum. In your first dissection you will be dis- 
 appointed at the frail condition of these sheaths at their lack of organization. 
 You will expect to find the sheath of an artery resemble a piece of heavy cloth 
 sewed tightly about the trunk of a tree ; your chagrin will be manifest when 
 you find it resembles more the investment of straw given tender shrubs to pre- 
 vent depredations of rodents in our parks. As any attempt to remove the pro- 
 tective from the tree would result in the complete destruction of the protective, as 
 you removed straw after straw, so, likewise, when you attempt to disen- 
 sheath a vessel you arrive at the vessel, but the sheath has disappeared. Re- 
 member, then, sheaths arc actual entities, and their architecture is adapted to the 
 needs and requirements of the vessel ensheathed, just as the cobweb is architect- 
 urally suited to the needs of the spider; still, when you molest the latter or 
 attempt to dissect the former, the result is the same each almost completely 
 disappears, such is the delicacy of their respective material. 
 
FUNDAMENTAL PRINCIPLES OF ANATOMY. 17 
 
 For the sake of gaining a conception of the architecture of sheaths and the 
 rationale of their formation by displacement of connective tissue, let the follow- 
 ing explanation be studied : Figure I represents a pot of earth in which various 
 seeds have been planted ; the pot is covered with a layer of absorbent 
 cotton, and exposed to the sun and rain. In time the cotyledons begin to 
 peep through the cotton ; as each becomes larger in diameter, it displaces 
 more cotton. As the cotton displaced by the growing plant may represent the 
 sheath of the plant, so, in like manner, to aid the memory, let us compare a 
 growing artery, bone, muscle, nerve, or gland surrounded by connective tissue 
 (which represents the cotton in the simile of the growing plant) to the plant. 
 The connective tissue would be displaced as the anatomical structure became 
 thicker, and this displaced tissue we call the sheath, capsule, tunic, toga, or 
 peristructure. 
 
 Now, by the same process account for periosteum, perimysium, perineurium, 
 and all peristructures and capsules. 
 
 PERIOSTEUM AND ITS FUNCTIONS. Periosteum is the anatomical investment 
 of bone. It covers all the bone except the articular surfaces. It is, as you 
 must demonstrate on your dissection, most intimately adherent to those parts of 
 the bone having the greatest number of irregularities. Its functions are as 
 follows : 
 
 1 . Osteogenetic, for it makes bone grow in thickness. 
 
 2. Protective, since it hinders progress of contiguous inflammation. 
 
 3. Attaclnnental, since it gives attachment to muscles. 
 
 4. Nutritive, since it feeds the bone with blood. 
 
 5. LAgamentous, since it forms all capsular ligaments. 
 
 6. Retentive, since it tends to retain ends of broken bones. 
 
 EMINENCES, DEPRESSIONS, AND SURFACES OF BONE are determined in shape 
 by the muscles associated therewith, and take the name of the muscle. You are 
 to look on muscular traction as the factor that determines the size of an eminence 
 or the depth of a fossa. In fact, the surfaces of bone are named according to 
 the occupant. In a given bone, as the humerus, name the articular surfaces 
 according to the occupants: (i) Scapular; (2) radial; (3) ulnar. Name the 
 surfaces according to the muscles. The posterior surface has an upper and a 
 lower tricipital surface, corresponding to the humeral heads of the triceps, etc. 
 Bicipital tuberosity, iliac fossa, gluteal ridge, deltoid impression, are instances. 
 You will observe that this rule is not always observed ; still the value of the rule 
 is no less. 
 
 ANATOMICAL WEAK POINTS comply with two conditions: (i) A location in 
 the continuity of the structure where there is a sudden abrupt cJiange in the 
 direction. (2) A functional area, as between skin and mucous membrane, as 
 where the small intestine opens into the large. In these localities fractures occur 
 in bone, aneurisms in arteries, morbid growths at muco-cutaneous areas. In 
 your dissection bear these areas in mind. Look for intussusceptions at the 
 weak points in the colon ; for fractures at the necks of bones, etc. 
 
 ANATOMICAL ROOTS are places uncovered by serous membrane, in connection 
 with viscera, where the vessels, nerves, and conduits enter to carry on (i) the 
 functional activity and (2) the nutritive activity of the organ. In your dissection 
 you will give special study to the root-structures of the heart, lung, liver, spleen, 
 kidney, intestine, ovary, testicle, etc. The functional activity is represented by 
 
i8 
 
 PRACTICAL ANATOMY. 
 
 what the organ does for the body in general ; the nutritive activity by what the 
 organ does for its own nutrition. The nutrient artery to organs is accompanied by 
 sympathetic nerves, which regulate the supply of blood each organ shall receive. 
 
 ANATOMICAL ANTAGONISM IN MUSCLES necessitates a consequent antagonism in 
 the nerves that supply these muscles, hence you will understand the meaning of 
 flexor, extensor, abductor, and adductor nerves. The very nature of logical 
 antagonism implies a degree of equality in length, weight, strength, and vantage 
 for origin and insertion. At the hip, flexors, extensors, abductors, and adductors 
 are seen. The antagonistic nerves are the anterior crural, the great sciatic, the 
 obturator, and the gluteal. 
 
 SHAPE OF MUSCLES AN INDEX TO THE PLACE WHERE THE MUSCLE RECEIVES 
 ITS NERVE-SUPPLY. I desire you to study carefully the following drawings, and 
 in your dissection you must faithfully determine the general shape of the muscle 
 and trace out the nerve thereto. 
 
 i. Triangular Muscles. The pectorales major and minor, the supra- and infra - 
 spinati, the subscapularis, the deltoid, the gluteals, the pyriformis, and 
 the obturators are examples ; take their nerve-supply near the apex. 
 
 FIG. 3. TRIANGULAR. FIG. 4. QUADRANGULAR. FIG. 5. FUSIFORM. FIG. 6. Ci.ri;i:i i>. 
 
 2. Quadrate Muscles. The pronator quadratus, the brachialis anticus, and 
 
 multifidus spinae are good examples ; take their nerve-supply near the 
 centre. 
 
 3. Fusiform Muscles. Take their nerve-supply near the middle. This, as the 
 
 biceps, is the same as No. 2, compressed at the ends. 
 
 4. Clubbed Muscles. This includes a large number, as those taking origin from 
 
 the outer and inner humeral condyles take their nerve-supply early. In 
 your work notice how very early the median gives off branches to supply 
 muscles of this type. 
 
 5. Scrrati muscles and those arising by more or less pronounced digitations, as 
 
 the serrati superior and inferior posticus, the diaphragm and the planiform 
 muscles of the abdominal walls, seem to conform to the type of triangu- 
 lar muscles, taking their nerve-supply near the apices of the digitate 
 origins ; still, if the nerves are traced out, they will be found to approach 
 the centre and conform to the quadrate type. 
 
 Remember, this tracing out of nerves belongs to macroscopic anatomy. To 
 gain an idea of the manner in which the ultimate tissue is innervated, you must 
 study up motorial end plates in physiology and histology. The only object in 
 
FUNDAMENTAL PRINCIPLES OF ANATOMY. 19 
 
 introducing the subject of shape of a muscle as an index to the nerve-supply 
 entrance is to impress the necessity of tracing out, as far as possible, in your dis- 
 section the branches of the nerves ; possibly the scheme introduced may aid the 
 memory. 
 
 HILTON'S LAW : Nerve trunks that supply muscles that move a joint supply 
 the joint acted upon with articular brandies ; they also supply the skin, covering 
 the fullest insertion of the muscle. Given, then, the number of antagonistic 
 groups of muscles, you are by this rule able to know the source from which the 
 joint is innervated. 
 
 ANATOMICAL APPOSITION Is NOWHERE FOUND. In dissecting in any region of 
 the body bear this in mind. Structures arc a fa ays disjunctively connected by a 
 layer of connective tissue. Found between muscles, it is called areolar or inter- 
 muscular connective ; beneath the pleura, subpleural ; beneath the peritoneum, 
 subperitoneal ; beneath mucous membrane, submucous ; beneath the periosteum, 
 subperiosteal. Notice the mortar between the bricks in a wall ; this corresponds 
 to connective tissue in anatomy. 
 
 DISSECTING Is THE ART OF DIVIDING THE CONNECTIVE TISSUE THAT INTER- 
 VENES BETWEEN ADJACENT STRUCTURES, and the division must be made in such a 
 manner as to do no violence to anatomical compounds, their nerve-supply, their 
 blood-supply, their excretory ducts, their capsules, and their anatomical relations. 
 
 FANCIFUL NAMES FOR MUSCLES, names founded on some one dominant idea, are 
 frequently met. It is to be regretted that our nomenclature could not have been 
 founded on the idea of function throughout. Note here that the substantive, 
 imtscitlns, while seldom expressed in our texts, is afaars implied. The following 
 will show you some of the names of muscles founded on fanciful ideas, and also 
 the full name as it should appear if founded on the idea of function : 
 
 FANCIFUL NAMES. PHYSIOLOGICAL NAMES. 
 
 Sartorius (tailor), .... Musculus extensor tibialis et adductor femoris. 
 Rhomboideus (geom.), . . Musculus levator scapulas rhomboideus. 
 Transversals (direct.), . . Musculus compressor abdominis transversalis. 
 
 Recius (geom.) Musculus flexor thoracis rectus. 
 
 Pyramida/is(geom.). . . . Musculus tensor lineas albae pyramidalis. 
 
 Vastus Externus, .... Musculus extensor vastus externus. 
 
 External Oblique, .... Musculus compressor abdominis obliquus externus. 
 
 Serratus Magnus, .... Musculus depressor scapulae serratus magnus. 
 
 Quadratus Lumborum, . Musculus flexor spins lateralis quadratus lumborum. 
 
 Latissimus Dorsi, .... Musculus abductor brachii latissimus dorsi. 
 
 Longissinms Dorsi, . . . Musculus extensor spinse longissimus dorsi. 
 
 ORBICULAR MUSCLES AND SPHINCTER MUSCLES. You will find the above 
 terms often used interchangeably. The important areas occupied by these 
 muscles make the majority of the same of prime interest to the general surgeon, 
 the genitp-urinaiy specialist, the gynaecologist, the obstetrician, the oculist, 
 the laryngologist, the rectal specialist, the patient. Still, no rational classification 
 of these muscles exists. At the present all orbiculars are sphincters, but not all 
 sphincters are orbiculars, as the following table, founded on usage, will show : 
 
 SYNONYMOUS USAGE. 
 
 Orbicularis oris Sphincter oris. 
 
 Orbicularis ani External sphincter ani. 
 
 Orbicularis palpebrarum, Sphincter palpebrarum. 
 
2 o PRACTICAL ANATOMY. 
 
 UNIVERSAL USE OF SPHINCTER. 
 
 Musculus sphincter vaginae. Musculus sphincter iridis. 
 
 Musculus sphincter urethrae. Musculus sphincter ilei. 
 
 Musculus sphincter prostatas. Musculus sphincter gulae. 
 
 Musculus sphincter cesophagei. Musculus sphincter vesicae. 
 Musculus sphincter laryngis. 
 
 As the following comparison will show, there is no good reason for confusion 
 of terms and an annoying interchange between orbicular muscles and sphincter 
 muscles. Such is usage. 
 
 Summary of Differences Between Orbiculars and Sphincters : 
 
 Orbicular s. 
 
 1. The orbiculars are supplied by spinal nerves. 
 
 2. The orbiculars are all voluntary. 
 
 3. The orbiculars are all dermal muscles. 
 
 4. The orbiculars are at muco-cutaneous margins. 
 
 5. The orbiculars move rapidly. 
 
 6. The orbiculars have parietal blood-supply. 
 
 7. The orbiculars are very sensitive to pain. 
 
 8. They refer their pain to place of irritation. 
 
 9. They report pain foudroyantly. 
 
 10. Their nerve-supply is somatic never sympathetic. 
 
 11. When lacerated, they repair slowly. 
 
 12. They are synonymous for sphincters in three cases only. 
 
 Sphincters. 
 
 1. Sphincters are supplied by the sympathetic. 
 
 2. They are all involuntary unstriped fibre. 
 
 3. They are not dermals, but viscerals. 
 
 4. They are never at muco-cutaneous areas. 
 
 5. They always move slowly. 
 
 6. They have visceral blood-supply. 
 
 7. They are not very sensitive to pain. 
 
 8. They refer pain to somatic areas. 
 
 9. Their own report of pain is dull and slow. 
 
 10. Their nerve-supply is sympathetic. 
 
 1 1. When lacerated, they repair readily. 
 
 The reader is referred to reflexes along somatic and sympathetic lines in the 
 dissection of the female pelvis. 
 
 TIic ('tents. 
 
 This would seem to be the most fully grown and fully developed structure 
 among the organs having sphincteric openings. Its proper sphincters aie 
 known as the os intcnntm and os cxternum. It complies in every way to eleven 
 points characteristic of sphincters. 
 
 GEOMETRICAL TERMS AND FIGURES. You will have much descriptive usage 
 along mathematical lines. This always aids the memory, for it appeals to the 
 basis of every one's education. 
 
 The axilla has base, apex, angles, and boundaries. 
 
 The neck has roof, floor, boundaries, and triangles. 
 
 Tlic nasal fossa has roof, floor, walls, and openings. 
 
 The orbit has roof, floor, base, apex, angles, and walls. 
 
FUNDAMENTAL PRINCIPLES OF ANATOMY. 21 
 
 77/6' mouth has roof, floor, sides, openings, dental arches. 
 
 The tympanum has roof, floor, and four walls. 
 
 Hunter's canal has roof, floor, boundaries, and extremities. 
 
 Scarpds triangle has roof, floor, base, apex, boundaries. 
 
 The iscldo-rcctal fossa has base, apex, walls, sacral and pubic ends. 
 
 The thorax has apex, base, anterior, posterior, and lateral walls. 
 
 Inguinal canal has rings, roof, floor, and two walls. 
 
 Popliteal space has roof, floor, extremities, and boundaries. 
 
 SUBSTANTIVE ADJECTIVES. These are so frequently used that I wish the 
 student early to learn to supply the missing substantive, not only in the case of 
 muscles, as referred to in nomenclature, but also in the case of arteries, veins, 
 nerves, and lymphatic glands. In social life, after long and thorough acquaintance 
 with your fellows, you justifiably dub your friends John, James, and the like, the 
 while mindful of the full baptismal name ; these liberties of address you would 
 consider improper in addressing comparative strangers. Likewise in anatomy 
 you speak of structures as follows : 
 
 i. A FRIEND. 2. A STRANGER. 
 
 The radial artery or vein Arteria radialis or vena radialis. 
 
 The ulnar artery or vein, Arteria ulnaris or vena ulnaris. 
 
 The brachial artery or vein, Arteria brachialis or vena brachialis. 
 
 The femoral artery or vein Arteria femoralis or vena femoralis. 
 
 The hepatic artery or vein, Arteria hepatica or vena hepatica. 
 
 The splenic artery or vein, Arteria splenica or vena splenica. 
 
 The vertebral artery or vein, .... Arteria vertebralis or vena vertebralis. 
 The mesenteric artery or vein, .... Arteria mesenterica or vena mesenterica. 
 
 The lingual artery or vein Arteria lingualis or vena lingualis. 
 
 The facial artery or vein, Arteria facialis or vena facialis. 
 
 Lymphatic Glands. 
 
 Cervical gland, Glandula lymphatica cervicalis. 
 
 Mesenteric gland, Glandula lymphatica mesenterica. 
 
 Inguinal gland, Glandula lymphatica inguinalis. 
 
 Axillary gland, Glandula lymphatica axillaria. 
 
 Epitrochlear gland, Glandula lymphatica epitrochlearis. 
 
 Nerves. 
 
 Radial, Nervus radialis. 
 
 Ulnar Nervus ulnaris. 
 
 Femoral, Nervus femoralis. 
 
 Lingual, Nervus lingualis. 
 
 Facial, Nervus facialis. 
 
 Circumflex Nervus circumflexus. 
 
 Great sciatic, Nervus sciaticus magnus. 
 
 Sympathetic, Nervus sympatheticus. 
 
 Remember, arteries, nerves, veins, lymphatics, and muscles are spoken of, 
 the country over, in the adjective abbreviated form by those who know what 
 they are talking about ; you, however, are not to speak of these structures in 
 the abbreviated form until you are familiar with the classical name. After such 
 knowledge has been acquired, then ahvays be governed by usage. 
 
 LAW OF PROJECTILES. In anatomy and physiology, in obstetrics and surgery, 
 in therapeutics and chemistry, we must frequently invoke a reason for the location 
 of a nerve or vessel ; for the direction taken by pus or a bullet ; for a misplaced 
 foetal head in utero ; or for the tracts pursued by pain and motion, when these 
 manifestations are far removed from their logical locality. The above pain, pus, 
 
22 PRACTICAL ANATOMY. 
 
 foetal, ovoid, bullet, and motion are all projectiles, and act in accordance with this 
 law : A projectile follows 
 
 1 . The point of least resistance. 
 
 2. The line of greatest traction. 
 
 3. The resultant of the two. 
 
 Grooves Transmitting Vessels and Nerves, and an Application of the 
 Law of Projectiles. You may be surprised, in your subsequent dissection 
 work on the cadaver, to find arteries and nerves, as a rule, in grooves. This, 
 however, is the case, and you are to name the groove according to the name of the 
 artery, except in those cases where the channel so expands as to be of great 
 surgical importance, in which case the space would seem rather to give its name 
 to the vessel. You are to learn and study these grooves according to roof, floor, 
 boundaries, and contents. If you can do this on the cadaver, then you will be 
 competent to do the same thing on a patient. You ask, Why do these structures 
 occupy grooves ? Philosophy answers, projectiles folloiv the line of least resistance. 
 
 APPLICATION OF THE LAW OF PROJECTILES IN THE CASE OF PAIN REMOTE 
 FROM PLACE OF INJURY. The cranio-spinal nerves are called somatic. Nerves 
 that supply the thoracic, abdominal, and pelvic viscera are called sympatJietic or 
 visceral. 
 
 A burn on the surface of the body is painful. The pain is violent and quickly 
 reported to the brain. No one, not even the physician, is in doubt as to the 
 location of the pain. The individual nerve-fibres of somatic nerves are of large 
 calibre, and the course of the same is not interrupted by ganglia. These condi- 
 tions would seem to favor rapid, direct transmission of both pain and motion. 
 
 In cancer of the stomach the pain is in the abdominal walls. In entcralgia the 
 pain is in the region of the umbilicus. In renal colic the pain is in the end of the 
 penis. In ovaritis the pain is in the back, chest, scalp, and upper or lower extremities. 
 In each instance above cited the pain is referred to a territory supplied by cerebro- 
 spinal and not by sympathetic nerves. In each instance the pain originates in 
 a territory supplied by sympathetics. In each instance pain is a projectile, 
 and must obey the universal law of projectiles. It is, then, the duty of physician 
 and student alike to trace out the anatomical tracks by which the pain rationally 
 travels. You will note, further, that in each case above cited the pain was referred 
 or reflected to the skin via those somatic nerves which had their origin nearest 
 the sympathetic plexuses from which the affected organs drew their sympathetic 
 nerve-supply. The only rational conclusion then is, it would seem, this : Pain 
 is referred to somatic areas because these nerves are so constructed as to offer 
 minimal resistance to the transmission of pain. In other words, projectiles follow 
 the line of least resistance. In your dissections you will be expected to find the 
 communications betiveen somatic and sympatJietic nerves. 
 
 FASCIA (PLURAL); FASCIA (SINGULAR). 
 
 The word "fascia" will probably occur more frequently in your anatomical 
 reading than any other word. The term means a sack or bundle, but any 
 amount of derivation, any amount of description in books, will give no adequate 
 idea of the application of the word fascia in all its various forms as met in dissect- 
 ing. The structure, to be understood and appreciated, must be seen and studied 
 on the cadaver. I submit this little outline on fascia, hoping thereby to give the 
 student a working basis for intelligent dissection. 
 
 There are two grand divisions of fasci;u : 
 
FUNDAMENTAL PRINCIPLES OF ANATOMY. 23 
 
 1. The superficial fascia, found under the skin in every region of the body. 
 This is also called in histology the areolar form of connective tissue. 
 
 2. The deep fascia or fascia profunda has the following characters : 
 
 (1) It is dense, heavy, and strong in some places ; weak in other places. 
 
 (2) It is attached to bone in subcutaneous areas. 
 
 (3) It has perforations for cutaneous vessels and nerves. 
 
 (4) It is attached to all eminences of bone in the vicinity of joints. 
 
 (5) It is a dense form of connective tissue. 
 
 (6) It receives many different names in different localities. 
 
 You will study the following description, and, if necessary, refer to it frequently 
 in your dissections. 
 
 SPECIAL NAMES AND SPECIAL FUNCTIONS OF FASCIA PROFUNDA. (i) In the 
 upper extremity ; (2) in the lower extremity ; (3) in association with muscles ; (4) 
 in surgical areas ; (5) forming intemnuscular septa. 
 
 In tlie upper extremity the deep fascia occurs as : 
 
 1. Anterior annular ligament lies in front of the carpus. Under this pass the 
 median nerve, flexor sublimis digitorum, flexor profundus digitorum, flexor longus 
 hallucis. This is ^ of an inch thick, extending from the os trapezium on thumb 
 side to the pisiform bone and unciform process of the unciform bone on ulnar 
 side. It is continuous below with the palmar fascia, and above with the deep 
 fascia covering the muscles. Its function is to bind down the structure under it. 
 
 2. Posterior annular ligament is behind the carpus. Under it pass the three 
 extensors of the thumb, the three carpal extensors, the extensor indicis, the 
 extensor minimi digiti, the extensor communis digitorum. It is continuous 
 above with the deep fascia covering the muscles, below with the fascia of the 
 back of the hand. It has seven synovial compartments. 
 
 3. Palmar fascia has an outer part, the thenar, covering the thenar eminence ; 
 an inner part, covering the hypothenar eminence ; a middle part, covering the 
 great distributing area to the fingers ; a neuro-vasal area, in which are the median 
 nerve, the ulnar nerve, and the superficial palmar arch. It is continuous above 
 with the annular ligament, below with the ligamenta vaginales ; laterally, with 
 the fascia dorsalis. 
 
 4. Dorsal fascia is on the dorsum of the hand. It binds the tendons down 
 and holds them together. It is continuous above with the annular ligament ; 
 below, with the extensor tendons. It is called fascia dorsalis mantis, in contra- 
 distinction to the fascia dorsalis pedis. 
 
 Ligamenta Taginales form dense sheaths for the flexor tendons of the fingers. 
 They are lined with synovial membrane called theca. The thecne terminate in 
 thecal culs-de-sac for all the fingers between the thumb and little finger op- 
 posite the metatarso-phalangeal articulation. The theca; for the little finger 
 and thumb terminate above in the general synovial sac under the anterior annular 
 ligament. Very often the thecae for the little finger and thumb terminate as do 
 the other three digits. 
 
 SPECIAL NAMES AND SPECIAL FUNCTIONS FOR THE DEEP FASCIA OF THE 
 LOWER EXTREMITY : 
 
 Fascia lata, the deep fascia on the front of the thigh. It has an iliac and 
 a pubic part, separated by the saphenous opening. It is continuous above with 
 Poupart's ligament ; below, with eminences about the knee. It is very dense 
 and strong. 
 
 Ilio-tibial band is in reality the aponeurotic insertion of the tensor vaginae 
 femoris muscle. The fascia or band is inserted into the eminences about the 
 outer part of knee. 
 
 Anterior annular ligament extends from malleolus to malleolus. Under it are 
 found the tibialis anticus, the extensor proprius hallucis, the extensor longus digi- 
 
24 PRACTICAL ANATOMY. 
 
 torum, the peroneus tertius, the anterior tibial artery and nerve. It is continu- 
 ous above with the deep fascia ; below, with the dorsal fascia. 
 
 External annular ligament extends from outer malleolus to os calcis. Under 
 it are the peroneus longus and peroneus brevis. On it rest the short saphenous 
 vein and nerve. 
 
 Internal annular ligament extends from inner malleolus to os calcis. Under 
 it are the tibialis posticus, the flexor longus digitorum, a sheath containing the 
 posterior tibial nerve, artery, and veins ; behind this sheath is the tendon of the 
 flexor longus hallucis. 
 
 Dorsal fascia fascia dorsalis pedis is on the back of the foot. It covers 
 the extensor muscles and the dorsalis pedis artery. It is continuous above with 
 the annular ligament ; below, with the extensor tendons to the toes. 
 
 Plantar fascia is on the sole of the foot. It has three parts, an outer or 
 hypothenar, an inner or thenar portion, a central portion. These cover three 
 muscles, forming the first layer. Behind, it is attached to the os calcis ; in front, it 
 is continuous with the ligamenta vaginales. 
 
 Liganicnta vaginales are strong sheaths for the flexor tendons. They are 
 lined by synovial membrane. These thecae all terminate in thecal culs-de-sac 
 i . 5 inches above the toe-clefts. 
 
 DEEP FASCIA ASSOCIATED WITH MUSCLES. The location of some muscles is 
 such that their action extraordinarily develops the fascial investment on one 
 surface of the muscle. This is always at the expense of the fascia on the other 
 side of the muscle. The fascia then takes the name of the muscle, as follows : 
 
 1 . Masseter muscle, masseteric fascia. 
 
 2. Temporal muscle, temporal fascia. 
 
 3. Deltoid muscle, deltoid fascia. 
 
 4. Supraspinous muscle, supraspinous fascia. 
 
 5. Infraspinous muscle, infraspinous fascia. 
 
 6. Obturator interims muscle, obturator fascia. 
 
 7. Iliac muscle, iliac fascia. 
 
 8. Transversalis muscle, transversalis fascia. 
 
 9. Pectoralis major muscle, pectoral fascia. 
 10. Biceps muscle, bicipital fascia. 
 
 DEEP FASCIA IN SURGICAL AREAS. I. The deep fascia helping to form the 
 base of the axilla is called axillary, suspensory. It is strong, continuous in front 
 with the pectoral ; externally, with the brachial ; posteriorly, with the fascia of 
 the latissimus dorsi. 
 
 2. Pelvic fascia has the following names according to muscle, function, etc. : 
 Iliac, iliac muscle ; psoas, psoas muscle ; obturator, obturator internus muscle ; 
 anal fascia, levator ani muscle ; pubo-prostatic, anterior ligament of bladder ; 
 recto-vesical ; pelvic white line ; inner layer of the triangular ligament. 
 
 3. Popliteal fascia helps to form the roof of the popliteal space. It possesses 
 some transverse muscular fibres, by which the resiliency of the fascia is kept up 
 in forced extension of the leg. It is perforated by the short saphenous vein and 
 nerve. 
 
 4. Cubital fascia covers the cubital fossa in the retiring angle of the elbou . 
 It covers the median nerve, the tendon of the biceps, the brachial artery and its 
 terminals, the radial and ulnar, and some of their branches. It is also called 
 bicipital fascia, semi lunar fascia, and falciform fascia. 
 
 DEEP FASCIA FORMING INTERMUSCULAR SEPTA. i. The group of muscles on 
 the front of the thigh is separated from the adductor group internally, and from 
 the flexor group posteriorly ; also, the flexor group is separated from the 
 adductor group. 
 
 2. The pcrotici muscles are separated from the flexors behind and the group 
 
FUNDAMENTAL PRINCIPLES OF ANATOMY. 25 
 
 on the anterior surface of the tibia and fibula in front. The superficial group 
 behind is separated from the deep group. 
 
 3. The radial group of the forearm is separated from the flexors in front and 
 the extensors behind. The superficial is separated from the deep group on the 
 anterior part of the forearm. 
 
 4. Groups of muscles, acting in harmony to discharge some one physiological 
 function, form a musculature. Adjacent musculatures are always separated by 
 septa of deep fascia. Each musculature has its own nerve-supply. Fascial septa 
 are always attached to the bone, being continuous there with the periosteum. 
 
 APONEUROSIS. The term aponeurosis, in the plural, aponeuroses, applies to 
 dense, strong fascia, in localities where the action of the fascia is intimately asso- 
 ciated in more than a secondary manner with that of a muscle. You will find 
 the aponeurosis of the diaphragm, of the internal and external oblique and trans- 
 versalis muscles of the abdomen, the occipito-frontal aponeurosis, the lumbar, 
 pharyngeal, and vertebral aponeuroses. In these places this structure forms 
 either an integral part of the muscle itself, or constitutes the main structure in 
 the region in which it is found. The terms aponeurosis of investment and inser- 
 tion refer to the structure as forming either a cover for a muscle or its insertion. 
 A single aponeurosis may do both of these. For instance, the aponeurosis of 
 investment for the glutens maximus muscle continues downward, and the 
 muscle is aponeurotically inserted thereby into the deep fascia of the thigh. 
 
 ORIGIN AND INSERTION OF MUSCLES. These are very arbitrary terms. 
 Usually the more fixed of two points is called the origin, the less fixed point, the 
 insertion. Insertion may be by tendon or by aponeuroses. Notice that many 
 muscles take a large part of their origin from the deep fascia investing them. 
 Attachment applies to both origin and insertion. 
 
 ANATOMICAL FIBROUS ARCHES. You will, in the course of your reading, see 
 the above expression. The two heads of muscles are always connected by a 
 fibrous arch. The following will illustrate the point : The gastrocnemius, 
 soleus, biceps, flexor sublimis digitorum, pronator radii teres, flexor longus 
 pollicis, the biceps of the thigh. Vessels and nerves are frequently described as 
 passing under the fibrous arch of a muscle. 
 
 THE SUPERFICIAL FASCIA 
 
 1. Is found immediately under the skin ; 
 
 2. It has two strata an upper and a lower ; 
 
 3. The upper stratum contains fat the panniculus adiposus ; 
 
 4. The lower stratum contains the cutaneous vessels and nerves ; 
 
 5. It has no fat in the eyelids, penis, and scrotum ; 
 
 6. It is not attached to bony eminences ; 
 
 7. It has some muscles, called dermals ; 
 
 8. Its local special names are cribriform and colles ; 
 
 9. Its fat in the palms and soles is called granular fat. 
 
 THE SEROUS MEMBRANES. You will be able to demonstrate on the cadaver 
 
 1 . They are all related to the lymphatic system ; 
 
 2. They form air-tight cavities, except the female peritoneum ; 
 
 3. They are all thin and transparent ; 
 
 4. They completely or partially invest organs ; 
 
 5. Peritoneum, pleura, and pericardium are proper serous membranes ; 
 
 6. The linings of blood-vessels and joints are subdivisions. 
 
 3 
 
26 PRACTICAL ANATOMY, 
 
 SYNOVIAL MEMBRANES. In your practical work on the cadaver you will find : 
 (i) Articular synovial membrane lining the capsules of movable joints; (2) 
 vaginal synovial membrane lining the ligamenta vaginales, surrounding the 
 tendons to the fingers and toes, and also in other places where a tendon would 
 be exposed to friction ; (3) bursal synovial membrane between an eminence of bone 
 and a muscle playing thereover. The secretion of these synovial membranes is, 
 by virtue of its viscidity, fitted to resist friction. Synovial membranes belong to 
 the class of serous membranes. 
 
 THE Mucous MEMBRANES. These communicate with the air. You will 
 demonstrate them lining the digestive tract, the genito-urinary passages, and the 
 respiratory tract. The margin between skin and mucous membrane is called a 
 muco-cutaneous margin. You must demonstrate this margin in all regions of 
 the body. The specific name of any muco-cutaneous margin is determined by 
 the name of the region, as : (i) The nasal ; (2) ocular ; (3) oral ; (4) anal ; and (5) 
 vaginal muco-cutaneous margin. These are all anatomical weak points, because 
 they are junctional areas. 
 
 NERVE-ENDINGS. You should remember that muscles receive both sensory 
 and motor nerves ; that nerve-endings are in tendon, blood-vessel, all the mem- 
 branes, and skin ; that you are not supposed to dissect out these nerve-endings 
 this belongs to histological and physiological research. You are to note where 
 the muscle receives its nerve-supply, usually on the under surface, and then 
 trace the same as far as possible. 
 
THE HEAD AND NECK. 
 
 Any attempt to dissect the general or special regions of the head -and, neck 
 must be preceded by a thorough review of those osteological parts associated (i) 
 with the attachment of muscles ; (2) with the limitation of surgical or physio- 
 logical areas ; (3) with the transmission of vessels and nerves ; (4) with junctional 
 areas, whether the union is fixed, as between the teeth and alveolus, or movable., 
 
 FIG. 7. THE SKULL. (Norma lateralis. ) 
 
 as between the mandible and the temporal bone. To accomplish this interesting 
 review let the illustrations in the book, the skull, and the cadaver all be used. 
 
 (Fig. 7-) 
 
 I. The complete temporal ridge has (i) a frontal portion ; (2) a parietal 
 portion; (3) a temporal portion. From it arises the temporal muscle and its 
 aponeurosis. The greater p^art of the temporal fossa is limited by it. It begins 
 
 27 ; 
 
28 
 
 PR A CTICAL ANA TOMY. 
 
 at the external angular process of the frontal bone and ends in the posterior root 
 of the zygomatic process of the temporal bone. The two ends are connected 
 by the zygomatic arcJi. 
 
 MENTAL 
 FORAMEN 
 Levator 
 menti 
 Depressor 
 labii inf. 
 THE CHIN OR 
 MENTAL PRO- 
 TUBERANCE 
 
 Temporal CORONOID PROCESS SIQMOID NOTCH External pterygoid 
 
 CONDYLE 
 
 Platysma 
 
 Depressor anguli oris 
 
 EXTERNAL OBLIQUE LINE 
 
 GROOVE FOR FACIAL ARTERY 
 
 ANGLE 
 
 FIG. 8. THE MANDIBLE. (Outer view.) 
 
 External 
 pterygoid 
 
 Capsule 
 
 MANDIBULAR 
 SPINE 
 
 MANDIBULAR 
 
 FORAMEN 
 
 Spheno-mandi- 
 
 bular ligament 
 
 Superior 
 
 constrictor 
 
 Mylo-hyoid 
 
 groove 
 
 Internal 
 pterygoid 
 
 Stylo- 
 
 mandibular 
 
 ligament 
 
 Temporal 
 
 GROOVE FOR SUB- 
 LINGUAL GLAND 
 Genio-hyo- 
 
 glOSBUS 
 
 Qeiiio-hyoid 
 
 Digastric 
 
 Mylo-hyoid 
 
 INTERNAL OBLIQUE LINE 
 
 GROOVE FOR SUBMAXILLARY GLAND 
 
 FIG. 9. THE MANDIIU.K. (Inner view.) 
 
 2. The zygomatic arch has (i)*a malar and (2) a temporal portion. It is 
 formed by the zygomatic process of the malar and the zygomatic process of 
 the temporal bone. The arch has an upper and a hwr border ; an outer and an 
 inner surface. 
 
THE HEAD AND NECK. 
 
 29 
 
 3. The mandible has a body and a ramus. On the body find : (i) The 
 mental foramen ; (2) the external oblique line ; (3) the alveolar process ; (4) the 
 symphysis menti ; (5) the mental tubercles ; (6) the incisive fossa ; (7) an internal 
 oblique line or mylo-hyoid ridge ; (8) a mandibular spine ; (9) a mandibular 
 foramen ; (10) superior and inferior genial tubercles ; (i i) a digastric fossa ; (12) 
 a submaxillary groove for the submaxillary gland. 
 
 Zygomaticuo 
 major 
 
 Zygomaticus 
 minor 
 
 SURFACE COVERED BY 
 oocipito-frontalis 
 
 Corrugator 
 superoilii 
 
 Tendo oculi 
 Crbicularia 
 
 palpebrarum 
 Levator labii supe- 
 
 rioris alaeque nasi 
 
 Levator labii 
 auperioria 
 
 Levator anguli oris 
 
 Compressor naris 
 
 Depressor alee nasi 
 Orbicularis oris 
 
 FIG. 10. THE SKULL. (Norma facialis.) 
 
 The ramus has (i) a coronoid process ; (2) a sigmoid notch ; (3) a condylar 
 process. The condylar process consists of a condyle and a neck. 
 
 ON THE FACE LOCATE (Fig. 10) : (i) The anterior nares ; (2) the nasal bones ; 
 (3) the temporal, frontal, orbital, and maxillary processes of the malar bone ; (4) 
 the supraorbital and infraorbital arches ; (5) the internal and external angular 
 processes of the frontal bone ; (6) the floor of the orbit, and in it the infraorbital 
 canal, containing an artery, nerve, and vein of the same name ; (7) the infra- 
 orbital foramen, the terminus of the infraorbital canal ; (8) the supraorbital 
 
3 
 
 PRACTICAL ANATOMY. 
 
 Maseeter 
 
 Tensor palati 
 Azygos uvulae 
 
 Superior constrictor 
 Internal pterygoid 
 
 Tensor palati 
 
 Tensor tympanl 
 
 Levator palati 
 
 Rectus capitis anticus major 
 
 Rectus capitis anticus minor 
 
 Anterior common ligament of spine 
 Vertical part of crucial ligament 
 
 Check ligament 
 Capsular ligament 
 
 Posterior oeeipito-atlantal ligament 
 Superior oblique 
 
 Rectus capitis posticus major 
 Rectus capitis postious minor 
 
 Iiigamentum nuchse 
 _ Trapezius 
 
 1 i<;. ii. -Tin SK.UI.L. (Nonna hasilaris.) 
 
THE HEAD AND NECK. 31 
 
 foramen in the frontal bone ; (9) the intermaxillary suture ; (10) the naso-frontal 
 suture ; (i i) the superciliary ridge ; (12) the interfrontal or metopic suture or its 
 remains. 
 
 ON THE BASE OF THE SKULL (Fig. 1 1) LOCATE: (i) The foramen magnum ; (2) 
 the occipital condyles ; (3) the digastric groove for the posterior belly of the digas- 
 tric muscle ; (4) the jugular process for the rectus capitis lateralis ; (5) the styloid 
 process of the temporal bone ; (6) the glenoid fossa with the Glaserian fissure 
 dividing the articular from the non-articular part of the same ; (7) the internal and 
 external pterygoid plates of the pterygoid process of the sphenoid bone ; (8) the 
 pterygoid fossa for the internal pterygoid muscle ; (9) the jugular foramen for 
 the ninth, tenth, eleventh nerves and jugular vein ; (10) the carotid canal in the 
 petrosa for the internal carotid artery and sympathetic nerve ; (i i) the foramen 
 spinosum for the great meningeal artery ; (12) the posterior nares 1(13) the hard 
 palate ; (14) the hamular process, around which plays the circumflexus palati. 
 
 LOCATE THE ATTACHMENT OF THESE MUSCLES (Figs. 7-10): (i) Temporal ; 
 (2) masseter ; (3) pterygoid, internal and external ; (4) buccinator ; (5) platysma ; 
 (6) digastric ; (7) orbicularis oris ; (8) depressor labii inferioris ; (9) levator menti ; 
 (10) levator labii superioris ; (i i) levator anguli oris ; (12) corrugator supercilii ; 
 (13) zygomaticus, major and minor ; (14) compressor naris ; (15) depressor alae 
 nasi ; (i 6) levator labii superioris alaeque nasi ; (17) the rectus capitis anticus, 
 major and minor; (18) the tensor palati; (19) the azygos uvulae; (20) levator 
 palati ; (21) tensor tympani ; (22) depressor anguli oris. 
 
 LOCATE THE FOLLOWING FISSURES : (i) The fronto-parietal ; (2) the temporo- 
 parietal ; (3) the interparietal or sagittal ; (4) the occipito-parietal ; (5) the 
 interfrontal ; (6) the fronto-nasal ; (7) the fronto-maxillary ; (8) the malo-frontal ; 
 (9) the malo-zygomatic ; (10) the malo-maxillary ; (11) the naso-maxillary ; 
 (12) the intermaxillary ; (13) the symphysis menti ; (14) the spheno-maxillary ; 
 (15) the petro-occipital ; (16) the palato-maxillary ; (17) temporo-mandibular 
 and occipito-atloid articulations are the only movable joints in this region. 
 
 INCISIONS FOR LOCATING THE FOLLOWING STRUCTURES : 
 
 1. The supraorbital nerve, artery, and vein (fifth nerve and seventh nerve). 
 
 2. The infraorbital nerve, artery, and vein (fifth nerve and seventh nerve). 
 
 3. The mental nerve, artery, and vein (fifth nerve and seventh nerve). 
 
 4. The facial artery and vein and their branches. 
 
 5. The facial nerve and its facial branches and communications. 
 
 6. The duct of Stenson and transverse facial artery. 
 
 The Mental Nerve. Turn the skin aside from the intersectional point indi- 
 cated in figure 1 2. With the forceps dissect out the leash of mental nerves, anp 
 find them continuous with branches of the facial nerve, or seventh cranial. (Fig. 
 1 6.) Find also the mental branch of the inferior dental artery coming through 
 the same foramen the mental. 
 
 The Supraorbital Nerve. Turn the skin back, beginning at the intersectional 
 point in the figure. Find with the forceps the leash of the supraorbital nerve 
 (Fig. 1 6) anastomosing with the supraorbital part of the facial portion of the 
 seventh nerve. 
 
 The Infraorbital Nerve. Turn the skin back, beginning at the intersectional 
 point in the figure. Here, with the forceps, you will find a large leash of nerves, 
 the terminus of the infraorbital nerve. You will see that its branches are con- 
 tinuous with the infraorbital portion of the seventh cranial nerve. Find also the 
 branches of the infraorbital artery accompanying the nerve. 
 
 Stenson' S duct is the excretory duct for the parotid gland. Turn the skin 
 back from the intersectional point indicated. Above the duct you will find the 
 transverse facial artery, a small branch of the temporal. Below the duct you 
 will find branches of the facial nerve. 
 
 
32 PRACTICAL ANATOMY. 
 
 The levator labii superioris covers the infraorbital nerve and artery. This 
 muscle arises from the margin of bone below the orbit. (Fig. 10.) It is inserted 
 into the orbicularis oris. 
 
 The levator anguli oris arises from the canine fossa below the infraorbital 
 foramen. It is inserted into the angle of the mouth. It may be seen by pulling 
 the leash of nerves to one side. The leash of nerves lies between the above two 
 muscles. (Fig. 10.) 
 
 The Depressor Labii Inferioris. Remove the skin a little further in the 
 region of the mental nerves, and find the depressor of the lower lip. This 
 muscle is quadrangular in form. Fully one-half of its outer surface lies under 
 
 \ 
 
 \ 
 
 FIG. 12. PRIMARY INCISIONS IN DISSKCTION 01 THE KACK. 
 
 the depressor anguli oris (Fig. 13). The muscle arises from the upper part of the 
 external oblique line of the mandible, and is inserted into the lower lip. 
 
 The depressor anguli oris (Fig. 13) will be found arising from the lower part 
 of the external oblique line of the mandible. It is triangular in form. It over- 
 laps the outer one-half of the depressor labii inferioris. Now cut the origin of 
 this muscle, and pull the same aside and expose the whole of the muscle that 
 it overlaps. (Fig. 17.) 
 
 CAUTION. In all dissections about the face care must be taken to cut close 
 to the skin. The branches of the seventh nerve lie beneath the muscles and 
 can not be injured if you take the precaution just given. 
 
THE HEAD AND NECK. 
 
 33 
 
 The Orbicularis Oris. Remove the skin around the mouth and expose this 
 muscle. (Fig. 14.) This muscle has a rather strong'fascial attachment to the 
 alveolus of the superior maxilla. ^ 
 
 The zygomatici major and minor (Fig. 14) arise from the malar bone, and 
 are inserted into the outer part of the upper lip. 
 
 The levator labii superioris alaeque nasi is inserted into the wing of the 
 nose and the upper lip. It arises from the nasal process of the superior maxilla, 
 on the margin of the orbit. 
 
 Corrugatpr 
 supercilii 
 
 Pyramidalis 
 
 Levator labii 
 
 superioris 
 
 alaeque naai 
 
 Levator labii 
 
 superioris 
 
 Compressor 
 
 narium 
 Levator anguli 
 
 oris 
 
 Naso-labialis 
 Depressor alae 
 
 nasi 
 Orbicularis oris 
 
 Buccinator 
 
 Depressor 
 
 anguli oris 
 
 Depressor labii 
 
 inferioris 
 Levator inenti 
 Mylo-hyoid 
 
 Anterior belly of 
 digastric 
 
 Temporal 
 
 Zygomaticua 
 major 
 
 Posterior belly 
 of digastric 
 
 Splenius capitis 
 
 Stylo-hyoid 
 
 Sterno-maatoid 
 
 Levator anguli 
 scapulae 
 
 Scalenus 
 medius 
 
 Scalenus anticus 
 
 FIG 13 THE DEEPER LAYER OK THE MUSCLES OF THE FACE AND NECK. 
 
 The Orbicularis palpebrarum surrounds the base of the orbit. It consists 
 of two sets of fibres. One, called the palpebral, covers the palpebra> or lids ; the 
 other is external to this, and blends above with the occipto-frontalis muscle. It 
 has, internally, a firm, triple attachment to the internal angular process of the 
 frontal bone, and to the nasal process of the superior maxilla. Between these 
 two you will find a short, stout tendon that can be mistaken for nothing else 
 the tendo oculi or tendo palpebrarum. Figure 10 shows its origin from the nasal 
 process of the superior maxilla in front of the lachrymal groove. Trace the 
 tendon toward the upper and lower lids and observe how it divides. 
 
34 
 
 PRACTICAL ANATOMY. 
 
 The Levator Menti, or Levator Labii Inferioris (Fig. 13). This is the 
 muscle by which the low"er lip is protruded and elevated at the same time. Cut 
 th/ough the mucous membrane and you will come to the muscular fibres. This 
 muscle arises from the incisive fossa, and is inserted into the integument of the 
 chin, on a plane lower than the origin of the muscle. 
 
 The compressor narium (Fig. 14), a small muscle, arises from the superior 
 maxilla. (Fig. 10.) It is inserted, by an aponeurosis across the bridge of the 
 nose, into its fellow of the opposite side. This is a small muscle at best, and 
 very hard to demonstrate on prepared material. 
 
 Epicranial 
 aponeuroais 
 
 Orbicularis palpebrarun 
 
 Fyramidalis 
 
 Levator labii superior-is 
 
 alscque na3i 
 Compressor narium 
 
 Dilatator naris anterior 
 Dilatator uaris posterior 
 
 Levator labii superioris 
 Zygomaticus minor 
 
 Levator anguli or is 
 Orbicularis oris 
 
 Depressor labii inferioris 
 Depressor anguli oris 
 
 FIG. 14. THE SUPERFICIAL MUSCLES OK THE HEAD AND NECK. 
 
 The corrugator supercilii (Fig. 13) is seen by cutting in the mid-line 
 above the nose through the skin and fasciae. It arises from the superciliary 
 ridge (Fig. 10), and is inserted into the under part of the orbicularis palpebrarum. 
 In action it produces the deep vertical furrows of the forehead. 
 
 The pyramidalis nasi (Fig. 14) is a part of the occipito-frontalis, continued 
 on to the nose, and inserted into the compressor narium. 
 
 The dilator naris anterior arises from the lateral cartilage of the nose, and 
 is inserted into the skin near the margin of the nose, well in front. 
 
THE HEAD AND NECK. 
 
 35 
 
 The dilator naris posterior arises from the superior maxillary bone, from 
 the nasal notch, and is inserted into the skin of the margin of the nostril, well 
 back. These two dilator muscles antagonize the compressor nariinu. Remove 
 the skin from the forehead, and expose the anterior belly of the occipito-frontalis. 
 We are at present concerned only with the insertion of this muscle. Its anterior 
 fibres are continued on to the nose as the pyramidalis nasi ; its middle and outer 
 blend with the outer portion of the orbicularis palpebrarum. 
 
 The muscles of facial expression, those which you have just dissected, 
 are called dermal muscles, on account of their insertion, being of such a nature 
 as to move the skin, in a most unique manner. These muscles are innervated by 
 the facial or seventh cranial nerve. (Fig. 16.) They are in the superficial fascia 
 in fact, they occupy the fascia to such a degree that some good authors speak of 
 the absence of facial superficial fascia. By their action they confer on the human 
 face facial expression in its broadest sense. 
 
 Is not the facial nerve more than an ordinary motor nerve ? In other words, 
 
 FIG. 15. SCHEME OF FACIAL NERVE COMMUNICATING WITH THE FIFTH CRANIAL NERVE. 
 
 is not this nerve eligible to promotion from the rank and file of ordinary motor 
 nerves to a place among those nerves which are designated special sense nerves ? 
 For the sake of arousing your interest in the difficult dissection of this nerve, 
 you will pardon a digression for the purpose of answering the above questions. 
 
 A slight blow on the ligamentum patellae produces reflex extension of the 
 leg on the thigh. The steps were (i) conduction of pain, by a sensory nerve, to 
 a cortical motor area, and (2) an almost simultaneous contraction of the extensor 
 quadriceps femoris ; (3) a record of the blow was recorded as memory. A com- 
 plete moto-sensory cycle was the result. The nerve that conveyed the sensation 
 of pain to the brain is called a nerve of common sensation ; the one that produced 
 motion in the extensor muscles is called a motor nerve. 
 
 The retina responds to light, the auditory nerve to sound, the olfactory, to 
 odors. Each nerve records its experience in the brain. Now, see what the 
 facial nerve does ! It produces motion of a reflex character, as do ordinary 
 motor nerves. It is the only nerve by which vision, audition, olfaction, and 
 
36 PRACTICAL ANATOMY. 
 
 gustation manifest themselves in the primitive state. The sight of cruelty, the 
 sound of martial music, the odor of Limburger cheese, the taste of some extra- 
 ordinary viand, are facially expressed, and read off by the world as disapproval, 
 patriotic enthusiasm, repulsion, satisfaction. If, then, auditory, optic, and 
 gustatory nerves are capable of conveying an impression to the brain for record, 
 are they entitled to the designation " special sense " any more than is the facial, 
 which does its own work, and facially expresses to the world the recorded 
 experiences of all the so-called nerves of special sense ? Is not this nerve a 
 special sense nerve of facial pantomime ? 
 
 SUPRA-ORBITAL 
 
 PALPEBRAL TWIG 
 
 OF" LACHRYMAL 
 
 INFRA TROCHLEAR 
 
 TEMPORAL 
 
 BRANCH OF 
 
 SEVENTH 
 
 MALAR BR. 
 OF SEVENTH 
 MAXILLARY 
 1)1 V. OF FIFTH 
 INFRA- 
 ORBITAL 
 BR. OF SEVENTH 
 
 BUCCAL BRANCH 
 OF SEVENTH 
 
 MENTAL BRANCH 
 OF MANDIBULAR 
 
 S UPRA -MA NDIB ULA R 
 BRASCH OF SEVENTH 
 
 INFRA -MA NDIB t Y, .1 K 
 BRANCH Of SEVENTH 
 
 POSTERIOR 
 
 AURIC I "I. Ml 
 
 A URICULO- 
 TEUPORAL 
 
 GREAT 
 OCCIPITAL 
 
 FACIAL 
 
 LESSER OCCIPITAL 
 GREAT A URICULAR 
 
 SUPERFICIAL 
 
 CERVICAL 
 
 FIG. 16. SUPERFICIAL DISTRIBUTION OF THE FACIAL AND OTHKK NKRVKS OF TIIK HKAD. 
 
 (After Hirschfeld and Leveille.) 
 
 The Facial Nerve (Fig. 16): Its Dissection on the Face. Remove the 
 skin. Cut down through the parotid gland in the direction of the vertical line in 
 figure 1 2. It is necessary to go through about one-half of an inch of gland sub- 
 stance. Take the forceps, and find a nerve trunk about the size of a knitting- 
 needle. This will be the inferior division of the nerve the cennco-facial part. 
 Follow this branch up a little further, and, very deeply located, you will find the 
 main tnin/c of the nerve. From this you can trace out all the facial branches, 
 in this manner : Put a small piece of tape around the main trunk. Pull on this, 
 
THE HEAD AND NECK. 37 
 
 and at the same time cut the skin, fascia, and gland substance, in the direction 
 of the branches, with scissors. You will find dissection of this nerve somewhat 
 difficult the first time you make the trial. Any amount of advice, added to 
 what has previously been said, will not help you. Just be careful, and expose 
 one branch at a time. 
 
 Communications of the Facial Nerve on the Face with other Nerves 
 
 (Fig. 15): 
 
 1. The seventh nerve -f- mental branch of the fifth nerve at mental foramen. 
 
 2. The seventh nerve + infraorbital branch of the v fifth nerve at infraorbital 
 foramen. 
 
 3. The seventh nerve + supraorbital branch of the fifth nerve at supraorbital 
 foramen. 
 
 4. The seventh nerve -f- auriculo-temporal branch of fifth on temporal muscle. 
 
 5. The seventh nerve + malar branch of temporo-malar of fifth nerve on 
 malar bone. 
 
 6. The seventh nerve + temporal branch of temporo-malar of fifth nerve 
 above zygoma. 
 
 7. The seventh nerve -f- great auricular nerve of cervical plexus behind the 
 ear. 
 
 8. The seventh nerve -j- small occipital nerve of cervical plexus behind the 
 ear. 
 
 9. The seventh nerve -f- lachrymal and infratrochlear branches of the fifth 
 nerve. 
 
 10. The seventh nerve -J- great occipital. Posterior division of second cer- 
 vical nerve. 
 
 It will appear from the foregoing that the nerve-supply of the face is a very 
 complicated proposition. Such, however, is not the case, since the whole nerve- 
 distribution can be reduced to : 
 
 1. Motor nerves to the muscles of expression = seventh nerve. 
 
 2. Sensory nerves to the skin over the muscles = fifth nerve. 
 
 3. Sympathetic nerves the nervi molles on facial artery. 
 
 4. Communicating branches to adjacent areas. 
 
 Divisions and Facial Branches of the Facial Nerve. The nerve divides 
 into two branches : (i) An upper division that supplies the upper half of the 
 face and the temporal region ; (2) a lower division that supplies the lower 
 half of the face and the neck. (Fig. 16.) 
 
 The temporo-facial division gives off : 
 
 1. Temporal branches to the temple and forehead. 
 
 2. Infraorbital branches below the orbit. 
 
 3. Malar branches to the zygomatic muscles. 
 The cervico-facial division gives off : 
 
 1. A buccal branch to the buccinator muscle. 
 
 2. A supramandibular branch above the jaw. 
 
 3. An inframandibular branch below the jaw. 
 
 The name pes anscrinus is applied to the divergence of these six nerves from 
 the two primary divisions of the seventh nerve. 
 
 The auriculo-temporal nerve will be found in front of the ear just behind 
 the temporal artery. It is a sensory branch of the fifth, and supplies the side of 
 the scalp and the external in front with sensation. 
 
 Find these arteries on the face (Fig. 1 7) : 
 
 1. The frontal in the inner angle of the orbit. 
 
 2. The nasal above the tendo oculi. 
 
 3. The lachrymal in the outer angle to the upper lid. 
 
 4. The transverse facial on the malar bone. 
 
3 8 PRACTICAL ANATOMY. 
 
 5. The supraorbital, with the supraorbital nerve. 
 
 6. The infraorbital, with the infraorbital nerve. 
 
 7. The mental, with the mental nerve. 
 
 8. The facial artery (Fig. 17) crosses the mandible in front oi the 
 masseter muscle. It is surrounded by some very delicate sympathetic nerves, 
 
 Orbicularia palpebrarum 
 muscle 
 
 Transverse facial artery 
 Zygomatious minor 
 muscle 
 
 Zygomatious major 
 muscle 
 
 Buccinator muscle 
 Masseterie branch 
 Masseter muscle 
 
 Stylo-pharyngeus 
 
 muscle 
 
 Stylo-glossus muscle 
 Ascending palatine 
 
 branch 
 Tonsillar branch 
 
 Facial artery 
 External carotid 
 artery 
 
 Posterior belly of 
 digastric muscle 
 
 Lingual artery 
 
 Frontal branch of ophthalmic 
 
 artery 
 
 Nasal branch of ophthalmic 
 artery 
 
 Angular artery 
 Levator labii super- 
 ior is et alas nasi 
 muscle 
 
 Infraorbital artery 
 Le'vator labii super- 
 ioris proprius 
 Lateralis nasi ar. 
 Levator anguli oris 
 muscle 
 
 Artery of septum 
 
 Superior coronary 
 
 artery 
 
 Risorius muscle 
 
 Inferior coronary artery 
 
 Mental branch of inferior 
 
 dental artery 
 Depressor labii inferioris 
 
 muscle 
 
 Inferior labial arlrrti 
 
 Depressor anguli oris 
 
 muscle 
 
 Submental artery 
 Branches to sitbmaxillary 
 gland 
 
 Anterior belly of digastric muscle 
 Mylo-hyoid muscle 
 
 Hyo-glossus muscle 
 
 HYl'OtiLOSSAL NERVE 
 
 Kic. 17. SCIIKMK OK TIIK FACIAL ARTKRY. 
 
 which can be demonstrated, if you remove all the fat, with ether, and permit the 
 ether to evaporate. These nerves are the ncri'i uiolles. They regulate blushing. 
 H miidics of the /'*iifid/ Artery on the Face : 
 
 1. The inferior coronary, between mucous membrane and orbicularis oris. 
 
 2. The superior coronary, between mucous membrane and orbicularis oris. 
 
 3. The inferior labial, under the muscles of the chin. 
 
THE HEAD AND NECK. 
 
 39 
 
 4. The lateralis nasi, to the side of the nose. 
 
 5. The angular, to the inner angle of the orbit. 
 
 6. Muscular branches to the various muscles. 
 
 Anastomosis takes place between the facial and all the arteries on the face 
 above enumerated. 
 
 The veins of the face (Fig. 18) accompany the arteries, and take the same 
 names, as a rule. (Fig. 17.) They must be dissected with the arteries and 
 
 Frontal 
 
 Stipraorbital vein 
 Communication with 
 
 ophthalmic vein 
 Transverse nasal vei> 
 
 Angular vein 
 Lateral nasal veins 
 
 Transverse facia 
 
 vein 
 Superior labial or 
 
 coronary vein 
 
 Anterior pterygoid 
 
 or deep facial vein 
 
 Inferior coronary 
 
 vein 
 
 Facial vein 
 
 Inferior labial vein 
 
 Submental vein 
 Lingual vein 
 
 Superior thyroid 
 vein 
 
 Middle thyroid 
 vein 
 
 Sterno-mastoid 
 
 Anterior jugular 
 
 vein 
 
 Communication 
 between anterior 
 jugular veins 
 
 Platysma 
 
 Anterior temporal vein 
 Posterior temporal rein 
 
 Deep temporal vein 
 Parotid lymphatic glands 
 Common temporal vein 
 Internal maxillary vein 
 Occipital vein 
 Temporo-maiillary vein 
 Posterior auricular vein 
 
 Occipital lymphatic glands 
 Sterno-masloid lymphatic 
 
 glands 
 
 Communication between 
 facial and external 
 jugular veins 
 Svbmaxillary lymphatic 
 
 glands 
 
 Internal jugular vein 
 Posterior external jugular 
 
 vein 
 External jugular vein 
 
 Superficial cervical chain 
 of glands 
 
 - Transverse 
 
 cervical vein 
 
 ^- Suprascapular 
 vein 
 
 Jugido-cephalic 
 vein 
 
 m 
 
 FIG. 18. THE SUPERFICIAL VEINS AND LYMPHATICS OF THE SCALP, FACE, AND NECK. 
 
 nerves. These veins must be handled very carefully, not to be injured, as they 
 are very easily ruptured. 
 
 Observe the deep temporal vein piercing the temporal fascia, above the 
 zygoma. This returns blood from the temporal muscle. Observe the confluence 
 of the internal maxillary vein, in front of the ear, in the substance of the parotid 
 gland, with the temporal vein, and the result of their confluence the temporo- 
 inaxillary vein. Observe the communication between the facial vein and the 
 external jugular; also the communication between the angular, supraorbital, 
 and ophthalmic veins. Erysipelas of the face may reach the meninges through 
 this communication. The ophthalmic vein opens into the cavernous sinus. 
 
40 PRACTICAL ANATOMY. 
 
 The parotid gland (Fig. 20) is located by limitation : 
 
 1. Superiorly, limited by the zygomatic arch. 
 
 2. Inferiorly, limited by the angle of the mandible. 
 
 3. Anteriorly, limited by the mid-line of the masseter. 
 
 4. Posteriorly, limited by the mastoid process and sterno-mastoid. 
 
 5. It sends in prolongations as follows (Fig. 19) : 
 
 The inner surface is irregular, sending (i) a large process of gland tissue, in 
 front of the styloid process of the temporal bone, the same also occupying the 
 non-articular part of the glenoid cavity ; (2) a large process behind the styloid 
 and under the mastoid process and sterno-cleido-mastoid muscle. 
 
 Parotid fascia is the name given to the deep fascia covering the outer sur- 
 
 PALATINE PROCESS OF SUPERIOR 
 MAXILLA 
 
 ZYGOMATIC ARCH 
 
 HORIZONTAL PLATE OF PALATE BONE 
 
 GLENOID FOSSA 
 
 rrnlid Gland 
 
 STVLOID PROCESS 
 Parotid Gland 
 
 MASTOID PROCESS 
 
 FIG. 19. SHOWING SCHEMATICALLY THE DEEP PART OK THE PAROTID GLAND EMBRACING 
 
 THE STYLOID PROCKSS. 
 
 face of this gland. You have already cut through the gland vertically to find 
 the seventh nerve. 
 
 Contents of the Parotid Gland : 
 
 1. The facial nerve and pes anserinus. 
 
 2. The auricula-temporal branch of the fifth nerve. 
 
 3. The external carotid artery and its three terminals. 
 
 4. The posterior auricular, temporal, and transverse facial arteries. 
 
 5. The internal maxillary artery and vein. 
 
 6. The temporo-inaxillary vein. 
 
 7. A branch of the great auricular nerve to the seventh. 
 
 Excretory Duct of the Parotid (Fig. 20). Stenson's duct crosses the 
 masseter muscle on a line from the centre of the upper lip to the lobule of the 
 ear. It perforates the buccinator muscle, and opens into the vestibule of the 
 oral cavity, opposite the second upper molar tooth. 
 
THE HEAD AND NECK. 41 
 
 1 . Hozv may the dermal muscles be grouped ? 
 
 They may be grouped about the four apertures : the orbit, the ear, the nose, 
 and the mouth. Their action seems to be secondary to the special senses of 
 hearing, smell, sight, and taste, since they open and close these openings to a 
 variable extent. 
 
 2 . Give the bony attachments of the orbiculans oris. 
 
 This muscle is attached to the upper and also to the lower incisive fossa, and 
 to the alveolar processes. 
 
 3. Has the orbiculans oris any antagonists? If so, name them. 
 
 Yes ; superiorly, levator labii superioris, levator anguli oris, zygomaticus 
 minor, zygomaticus major ; inferiorly, depressor labii inferioris, depressor anguli 
 oris, levator menti, risorius. 
 
 SOCIA PAROTIDIS 
 
 SUBLINGUAL GLAND 
 
 DUCT OF SUBMAXILLARY 
 
 GLAND 
 Mylo-hyoid muscle 
 
 Anterior belly of 
 digastric muscle 
 
 DEEP PORTION OF SUBMAXILLARY GLAND 
 
 FIG. 20. THE SALIVARY GLANDS. 
 
 PAROTID GLAND 
 
 Massetcr muscle 
 
 Ster no -m astoid 
 muscle 
 
 Posterior belly of 
 digastric muscle 
 
 SUBMAXILLARY GLAND. 
 DRAWN BACKWARDS 
 
 Loop of fascia 
 
 4. Name the foramen between the origins of the levator labii superioris and the 
 levator anguli oris. 
 
 The infraorbital, transmitting the infraorbital vessels and nerves. 
 
 5. Locate on a patient the foramen mental c t and tell what it transmits. 
 
 This foramen is located at the junction of the mento-Meckelian and dentary 
 parts of the mandible, one-half of an inch below the gingiva of the second bicuspid 
 tooth ; it transmits the mental branches of the inferior dental vessels and nerves. 
 
 6. What is the function of the mental nerves and with what do they communi- 
 cate ? 
 
 The function is to supply the skin of the lower lip and chin ; they communi- 
 cate with mental branches of the facial nerve. 
 
 7. Name the aural group of dermal muscles, and give their function. 
 Attrahens aurem, attolens aurem, retrahens aurem. These muscles are mere 
 
 vestiges in man, often incapable of demonstration. They are best studied on 
 domestic animals, as the dog and rabbit. Their function is, first, to enlarge the 
 4 
 
42 PRACTICAL ANATOMY. 
 
 auditory canal by rendering tense the cartilaginous parts ; and, second, to direct 
 the external ear toward a given noise. These muscles are supplied by the 
 seventh cranial nerve. 
 
 8. Describe the rationale of a complete frown. 
 
 A proper frown consists of vertical and horizontal corrugations. The verti- 
 cals are produced by the action of the corrugator supercilii on the anterior belly 
 of the occipito-frontalis muscle, acting on this so as to deflect inward its muscular 
 belly and the skin covering the same. The horizontal ridges are the result of 
 the same force, intensified to some extent by gravity. 
 
 9. Locate the infraorbital plexus and give its formation. 
 
 It is located one-half of an inch external to the wing of the nose. It lies 
 
 
 Submaxillary 
 
 Superior carotid 
 
 Occipital 
 
 Inferior carotid 
 
 Fir,. 21. CERVICAL TRIANGI.KS. 
 
 under cover of the levator labii superioris, and is formed by a. communication 
 between the infraorbital branch of the fifth and the infraorbital branches of the 
 seventh nerve. 
 
 10. Name and locate the great anastomotic blood areas on the face and tell limv 
 they are formed, 
 
 The facial branch of the external carotid, the ophthalmic branch of the 
 internal carotid artery, the internal maxillary branch of the external carotid, and 
 the temporal branches of the external carotid are the branches of arterial trunks 
 concerned in the rich blood-supply to the face. 
 
 Anastomotic areas: (Fig. 17) (i) The ophthalmic anastomoses with the tem- 
 poral, forming the supraorbital anastomosis, and with the angular branch of 
 the facial artery at the iniu-r base of the orbit, forming the angular anastomosis. 
 ( 2) The transverse facial artery anastomoses with the masseteric branch of the 
 
THE HEAD AND NECK. 43 
 
 facial artery on the outer surface of the masseter muscle, forming the masseteric 
 anastomosis. (3) The infraorbital anastomoses with the facial, below the orbit, 
 to form the infraorbital anastomosis. (4) The mental branch of the inferior 
 dental artery anastomoses with the inferior labial branch of the facial artery, 
 forming the mental anastomosis. (5) In the facial mid-line the corresponding 
 arteries of opposite sides of the face anastomose. At the aural, ocular, nasal, 
 and oral muco-cutaneous junctions capillary anastomosis takes place. (6) The 
 arterial anastomoses above referred to are attended by venous anastomoses. 
 The mental, infraorbital, and supraorbital may be compressed at their respective 
 exit foramina. The facial may be compressed on the mandible just in front of the 
 masseter muscle. (7) The important communication on the face is between the 
 ophthalmic and angular, by which route facial erysipelas may reach the meninges, 
 since the ophthalmic vein opens into the cavernous sinus of the dura mater. 
 
 1 1 . Explain briefly the parotid gland. 
 
 The gland is located in a depression having the following limitations : above, 
 the zygomatic arch ; below, the angle of the mandible and the masto-mandibular 
 line; behind, the external ear and sterno-mastoid muscle; in front, by the masseter 
 muscle ; deeply, it embraces the styloid processes and internal carotid artery. 
 The gland contains the seventh nerve and the auriculo-temporal branch of the 
 fifth nerve, both of which furnish it with nerve -filaments. It contains the external 
 carotid artery, which here breaks up into the temporal, internal maxillary, and 
 transverse facial branches ; these supply the gland with blood. It contains the 
 temporo-maxillary vein. The fascial covering of the gland is called the parotid 
 fascia. The gland is the largest of the salivary glands, and has an excretory 
 duct called Stenson's. 
 
 12. Trace Stenson's duct. 
 
 It crosses the masseter muscle in a line from the lobule of the ear to the 
 upper lip. It perforates the buccinator muscle, and opens into the vestibule of 
 the cavum oris opposite the second upper molar tooth. 
 
 13. Where does the facial nerve escape from the cranium ? 
 
 It escapes through the stylo-mastoid foramen, in the petrosa of the temporal 
 bone. On its escape it gives off the posterior auricular, the digastric, and stylo- 
 hyoid branches. It subsequently forms the pes anserinus, from which the 
 muscles of expression are innervated. The facial is a motor nerve. 
 
 NOTE. Many a good dentist has been heard to tell his patient, "All this 
 toothache is caused by the facial nerve." The facial nerve makes you smile when 
 you hear such things ; it is the fifth nerve that is concerned in toothache. 
 
 THE NECK. SUPERFICIAL DISSECTION. 
 
 Locate on the cadaver : 
 
 1. The lower border of the mandible and its angle. 
 
 2. The mastoid process of the temporal bone, behind the ear. 
 
 3. The sterno-clavicular articulation. Does it move? 
 
 4. The interclavicular or suprasternal notch. How deep? 
 
 5. The acromio-clavicular articulation. Does it move? 
 
 6. An imaginary line from the angle of the jaw to the mastoid. 
 
 7. The sterno-cleido-mastoid muscle and its double origin. 
 
 8. The exact anterior border of sterno-cleido-mastoid. 
 
 9. The exact posterior border of sterno-cleido-mastoid. 
 10. The cervical mid-line mento-sternal line. 
 
44 PRACTICAL ANATOMY. 
 
 1 1. The hyoid bone in the mid mento-sternal line. 
 
 1 2. The body of the hyoid bone, one-half of an inch long to touch. 
 
 13. The greater horn of the hyoid -{- lingual artery above same. 
 
 14. The thyroid cartilage Adam's apple and notch above, 
 i 5 . The thyro-hyoid space + thyro-hyoid membrane. 
 
 1 6. The thyroid notch -f- mid-part of thyro-hyoid membrane. 
 
 17. The crico-thyroid membrane in crico-thyroid space. 
 
 18. The cricoid cartilage and trachea. (Fig. 27.) 
 
 INCISIONS. 
 
 1 . Through the mid mento-sternal line. 
 
 2. From symphysis menti to mastoid process. 
 
 3. From sternum to acromion process. 
 
 BOUNDARIES OF THE NECK. 
 
 1 . Anterior. -The mid mento-sternal line. 
 
 2. Posterior. The anterior border of the trapezius. 
 
 3. Inferior. The clavicle and manubrium sterni. 
 
 4. Superior. Lower border of mandible and masto-mandibular line. 
 
 TRIANGLES OF THE NECK. (Fig. 21.) 
 
 1 . Submaxillary or digastric. 
 
 2. Superior carotid or triangle of election. 
 
 3. Inferior carotid, tracheal, or triangle of necessity. 
 
 4. Occipital not suboccipital. 
 
 5. Subclavian or brachial triangle. 
 
 BOUNDARY STRUCTURES OF CERVICAL TRIANGLES. (Fig. 23.) 
 
 1 . The sterno-cleido-mastoid muscle. 
 
 2. The mid mento-sternal line. 
 
 3. The lower border of the mandible. 
 
 4. The masto-mandibular line. 
 
 5. The omo-hyoid muscle. 
 
 6. The digastric muscle. 
 
 7. The stylo-hyoid muscle. 
 
 8. The manubrium sterni and clavicle. 
 
 SURGICAL AND MEDICAL AREAS OF THE NECK. 
 
 Larynx intubation and laryngotomy. 
 
 Trachea tracheotomy, high and low. 
 
 Thyroid gland operations on. 
 
 The contents of the carotid sheath. 
 
 The subclavian artery and its branches. 
 
 The brachial and cervical plexuses. 
 
 The apex of the lung, one and one-half inches above the first rib. 
 
 Traclical and bronchial respiration. 
 
 The superficial lymphatic glands. (Fig. 23.) 
 
 The upper set of deep lymphatic glands. 
 
 The low i- sc/ of deep 'lymphatic glands. 
 

 THE HEAD AND NECK. 45 
 
 SPECIFIC BOUNDARIES OF CERVICAL TRIANGLES. (Fig. 23.) 
 
 1. Digastric Triangle. Mandible and masto-mandibular line ; anterior belly 
 of digastric muscle ; posterior belly of digastric muscle and stylo-hyoid muscle. 
 
 2. Superior Carotid Triangle. Sterno-cleido-mastoid muscle ; anterior belly 
 of omo-hyoid muscle ; stylo-hyoid muscle and posterior belly of digastric muscle. 
 
 3. Inferior Carotid or Traclieal Triangle. Mid mento-sternal line ; sterno- 
 cleido-mastoid muscle ; anterior belly of omo-hyoid muscle. 
 
 4. The Occipital Triangle. The trapezius muscle; the posterior belly of the 
 omo-hyoid muscle ; the sterno-mastoid muscle. 
 
 5. 'The Subclaman Triangle. The clavicle ; the posterior belly of the omo- 
 hyoid muscle ; the sterno-cleido-mastoid muscle. 
 
 Note that the sterno-mastoid divides the neck into two triangles. Of these 
 two the anterior contains three, the posterior two, smaller triangles. 
 
 Dissection to sJwiv superficial structures in the superficial fascia of tJie neck, 
 as follou'S : 
 
 1 . The platysma myoides muscle a dermal. 
 
 2. The anterior jugular vein is in front of sterno-mastoid. 
 
 3. The posterior jugular vein is behind the sterno-mastoid. 
 
 4. External jugular vein crosses the sterno-mastoid. 
 
 5. The superficial lymphatics vertical group. (Fig. 23.) 
 
 6. The superficial lymphatics transverse group. (Fig. 23.) 
 
 7. The inframandibular branch of the seventh nerve. (Fig. 22.) 
 
 8. The superficial cervical nerve, of cervical plexus. (Fig. 22.) 
 
 9. The great auricular nerve, of cervical plexus. (Fig. 22.) 
 
 10. The small occipital nerve, of cervical plexus. (Fig. 22.) 
 
 11. The suprasternal nerve, of cervical plexus. (Fig. 22.) 
 
 12. The supraclavicular nerve, of cervical plexus. (Fig. 22.) 
 
 13. The supraacromial nerve, of the cervical plexus. (Fig. 22.) 
 
 The platysma myoides (Fig. 14) is a dermal muscle. It is allied to the 
 muscles of expression and to the three dermal aural muscles ; they are all rem- 
 nants in man of the great panniculus carnosus. To expose this muscle it will 
 be necessary to exercise the greatest care in removing the skin. Usually the 
 fibres of origin of this muscle extend two .inches below the clavicle. They are 
 continued obliquely upward and forward onto the face. In some persons this 
 muscle is very heavy ; in others it is almost absent. 
 
 The Superficial Nerves of the Cervical Plexus and the Spinal Accessory 
 Nerve. Dissection. Locate the posterior border of the sterno-cleido-mastoid 
 muscle. Very carefully cut the platysma along this posterior border, using the 
 forceps for a director. Next cut through the deep fascia along the posterior border 
 of the muscle. Now look first for a small nerve that parallels the posterior border 
 of the sterno-cleido-mastoid muscle. (Fig. '22. ) This is the lesser occipital. 
 Trace it upward, as in the figure. 
 
 Three nerves cross the sterno-cleido-mastoid: (i) The mastoid branch, or 
 second small occipital ; (2) the great occipital ; (3) the superficial cervical. 
 
 Follow their branches out, taking care to harm no veins. These are the 
 three ascending branches of the plexus. 
 
 The spinal accessory nerve is sometimes the subject of surgical procedure. 
 On the living, if you are in doubt as to whether you have the spinal accessory 
 or some other nerve, remember this rule : Pinch the nerve with the forceps, and 
 if it is the spinal accessory you have, the trapezius muscle will elevate the 
 shoulder-blade. The other nerves that this one is sometimes mistaken for are 
 all sensory, and will, if pinched, produce no muscular contraction. 
 
46 PRACTICAL ANATOMY. 
 
 The descending branches of the cervical plexus are (i) the suprasternal, 
 (2) the supraclavicular, (3) the supraacromial. Trace these out, as in figure 22. 
 
 Note that the superficial cervical branch passes behind the external jugular 
 vein ; that it is distributed to almost the entire front of the neck ; that it anasto- 
 moses above with the inframandibular branch of the seventh nerve and below 
 with the suprasternal. 
 
 Note the spinal accessory nerve pierces the tapezius muscle, and has many 
 communications with the other nerves in the occipital triangle. To this fact is 
 
 POSTERIOR 
 A URICULAR 
 
 NERVE 
 
 FACIAL NERVE 
 
 AURICULAR BR. OF 
 
 ORE A T A URICULAR 
 
 INFRAHANVIBULAR 
 
 SUPERFICIAL CERVICAL 
 BRANCHES OF SUPER- 
 FICIAL CERVICAL 
 NER VE 
 
 SUPRASTERNAL 
 
 ) BRANCHES OF 
 }- GREA T 
 \ AURICULAR 
 
 C RE AT OCCIPITAL 
 
 LESSER OCCIPITAL 
 
 GREAT AURICULAR 
 MASTOID BR. OH 2nd 
 
 SMALL OCCIPITAL 
 SPI.VAL ACCESSORY 
 
 TWIGS FROM THE 
 .VASTOID BRANCU 
 
 BR. TO LKVATOR 
 
 A\<;ri.i si-AWLji 
 
 SI' PR A- A CROMIAL 
 Sl'PRACLAVICCLAR 
 
 BRANCHES TO 
 
 TR APEX I US 
 
 si 8OPBACU.rtC1tLAM 
 
 FIG. 22. SUPERFICIAL BRANCHES OF THE CERVICAL PLEXUS. (After Hirschfeld and Leveille.) 
 
 possibly due the twitching of the shoulder in frostbitten ears ; purely a reflex 
 movement. (Fig. 22.) 
 
 The Superficial Lymphatic T. This will enable you to remember the 
 general distribution of the superficial lymphatic glands in the neck. (Fig. 23.) 
 In the main the lymphatics follow the veins. They are readily seen win 11 
 enlarged by disease ; they are scarcely recognizable in cadavers when not diseased. 
 
 The jugular veins (Fig. 18) in the superficial fascia are : (i) The anterior, 
 near the mid inento-sternal line. It opens into the *iibela:>ian rein or into the 
 external jugular under the stcrno-cleido-mastoid muscle. (2) The posterior jugular 
 
THE HEAD AND NECK. 
 
 47 
 
 vein parallels the posterior border of the sterno-cleido-mastoid muscle. It opens 
 into the external jugular vein. (3) The external jugular 'vein crosses the sterno- 
 cleido-mastoid muscle. It is formed, as you must show, by the confluence of 
 (i) the temporo-maxillary, (2) the posterior auricular and facial communicating 
 branch. 
 
 THE DEEP CERVICAL FASCIA. 
 
 I desire the student to have a conception of the deep fascia of the neck, in 
 advance of his work. The following scheme will greatly assist him both in 
 review and during the dissection. 
 
 i . The deep fascia ensheathes the contents of the neck in four strata. The 
 
 Horizontal ramus of 
 lymphatic T 
 
 Vertical ramus of 
 lymphatic T 
 
 , 
 
 FIG. 23. SUPERFICIAL LYMPHATICS. 
 
 student is expected to learn just what structures are ensheathed by each layer 
 of fascia. 
 
 2. The deep fascia has superior attachments, relations, and specializations ; 
 it also has inferior attachments and continuations, thoracic and maxillary, which 
 the student must learn if he ever expects to dissect the neck and thorax under- 
 standingly. 
 
 3. The deep fascia forms septa and sheaths, the rationale of which must be 
 read and studied in the introductory chapter of this book. The deep fascia 
 here, as in every region of the body, belongs to the dense compact variety of 
 connective tissue. 
 
48 PRACTICAL ANATOMY. 
 
 4. The deep fascia determines the course taken by pus and missiles, hence a 
 thorough knowledge of the architecture of the deep fascial envelopes of the 
 neck is just as important as any fascial area in the body. 
 
 Figure 24 represents schematically a transverse section of the neck. From 
 this it will be seen there are two spaces: (i) Those formed by delamina- 
 tion of the four layers, including certain structures and their nerve-supply and 
 blood-supply. (2) The interfascial spaces containing fat and connective tissue. 
 It will be seen that the first layer delaminates to unsheath the sterno-rnastoid 
 muscle. The second layer delaminates to enclose the omo-hyoid, sterno-hyoid, 
 sterno-thyroid, and thyro-hyoid muscles, with their nerve -supply and blood- 
 supply. The third layer delaminates to enclose the larynx and trachea and 
 thyroid, the pharynx and oesophagus, the carotid sheath and its contents. The 
 fourth layer delaminates to ensheath the rectus capitis anticus major and minor 
 and longus colli muscles. 
 
 First layer 
 
 Second layer 
 
 Third layer 
 
 Fourth layer 
 
 FIG. 24. DEEP CERVICAL FASCIA TRANSVERSE SECTION. (Schematic.) 
 
 Dissection : 
 
 1. The temporal muscle and its aponeurosis or fascia. 
 
 2. The masseter muscle and its aponeurosis or fascia. 
 
 3. The sterno-cleido-mastoid and its fascial covering. 
 
 4. The trapezius muscle and its aponeurosis. 
 
 5. The zygoma, and its relations. 
 
 6. The temporal fossa and its contents. 
 
 7. The temporal ridge, its formation of three parts. 
 
 Examine your work and answer this quiz : 
 
 1. Name the deep fascia covering the temporal muscle and give all its attach- 
 ments. 
 
 It is called the temporal fascia. It is attached to the linea suprema of the 
 complete temporal ridge, and to the superior border of the zygomatic arch. 
 
 2. What does the complete temporal ridge consist of Y 
 
 It consists of two parallel lines, having a frontal, a parietal, and a temporal 
 portion. The aponeurosis of the muscle arises from the upper, the muscle itself 
 from the lower line. 
 
 3. \Vhat structures occupy the superficial fascia, covering the temporal muscle / 
 The superficial temporal arteries and their veins ; the auriculo-temporal nerve, a 
 
 branch of the fifth cranial ; some temporal brandies of the seventh or facial nerve, 
 and the lesser occipital nerve. 
 
THE HEAD AND NECK. 49 
 
 4. Wliat is the massctcric fascia ? 
 
 The deep fascia covering the masseter muscle. It is of cervical derivation, 
 being, with the parotid fascia, the upward continuation of the first layer of the 
 deep cervical fascia. 
 
 5. Name the structures on tlie masseter muscle . 
 
 The parotid gland in part; the pes anserinus of the seventh nerve ; Stenson's 
 duct. In front of and under the anterior part of the muscle is some fat, called in 
 the child the sucking pad. 
 
 6. Explain the relations and composition of the zygomatic arch. 
 
 The arch is composed of a malar and a temporal portion. It has a superior 
 border into which is inserted the temporal fascia ; an outer surface that is 
 subcutaneous ; an inner surface and a lower border from which arises the 
 masseter muscle. Under the arch' are found the coracoid process of the 
 temporal bone, into which is inserted the temporal muscle ; the sigmoid notch, 
 through which pass the arteries and nerves to the masseter muscle. 
 
 7. What structures lie on, and posterior to, the sterno-cleido-mastoid muscle ? 
 The muscle is ensheathed by the first layer of the deep cervical fascia. 
 
 (Fig. 24.) On the muscle lie the auricularis magnus and the superficial cervical 
 nerves. The muscle is crossed by the external jugular vein. The spinal 
 accessory nerve and all the superficial branches of the cervical plexus pierce the 
 deep fascia at the posterior border of the muscle. These nerves are all in the 
 occipital triangle. 
 
 8. Describe the superficial branches of the cervical plexus. (Fig. 22.) 
 
 They are seven in number. The four ascending branches supply the neck 
 and side of the head with sensation. The three descending branches supply the 
 shoulder and upper third of the thorax. Their names are : 
 
 1. Lesser occipital parallels the sterno-cleido-mastoid muscle. It supplies 
 the skin over the temporal muscle and the upper posterior part of the ear. 
 
 2. The mastoid branch, or second small occipital, supplies the skin over the 
 insertion of the sterno-mastoid muscle into the mastoid process of the temporal 
 bone. 
 
 3. The great auricular crosses the sterno-mastoid muscle to the ear, to which 
 and to the skin over the the parotid it is distributed. 
 
 4. The superficial cervical nerve crosses horizontally the sterno-mastoid 
 muscle. It supplies with sensation the whole front of the neck. It passes be- 
 hind the external jugular vein. 
 
 5. Suprasternal. This nerve supplies the skin over the origin of the sterno- 
 mastoid and over the manubrium sterni. 
 
 6. The supraclavicular supplies the skin over the pectoralis major to the 
 nipple. It probably is this nerve that may account for the very diffuse pain over 
 the head, neck, and shoulders in sore nipples of nursing mothers. 
 
 7. The supraacromial supplies the skin over the deltoid and clavicular por- 
 tion of the trapezius muscles. 
 
 The Masseter Muscle (Fig. 25). Cut this muscle at its origin from the 
 malar process of the maxilla and the inner surface and lower border of the 
 zygoma. As you turn the same down, notice the nerve- and blood-supply 
 coming through the sigmoid notch. A little work with the forceps will remove 
 the fat and develop the insertion of the temporal muscle into the coracoid 
 process. Find the masseter inserted into the outer surface of the ramus of the 
 mandible. 
 
So PRACTICAL ANATOMY. 
 
 The Temporal Muscle (Fig. 25). Cut the aponeurosis of this muscle around 
 the whole circumference of the temporal fossa. The aponeurosis will be attached 
 to the zygoma in t\vo layers. Find between these two layers a small branch of 
 the temporo-malar nerve. The nerve will do you no good ; but finding the 
 same will be evidence of careful work. Turn the muscle itself down, after hav- 
 ing removed the fascia, and see the deep temporal arteries. These supply the 
 muscle with blood. They lie on the bone. They are branches of the internal 
 maxillary. Find the deep temporal vein (Fig. 18) piercing the fascia above the 
 zygoma, to join the superficial temporal. 
 
 The sterno-cleido-mastoid muscle (Fig. 25) has two origins : (i) A sternal ; 
 
 FIG. 25. MUSCLES OF THE FACE AND NECK. 
 
 I. Frontal muscle. 2. Occipital muscle. 3, 3. Epicranial aponeurosis. 4. Temporal muscle. 5. Ketra- 
 hens aurem. 6. Orbicularis palpebrarum. 7. Levator labii superioris et abeque nasi. 8. Dilator 
 naris. 9. Compressor naris. 9'. Pyramidalis nasi. lo. Zygomatic minor, i-i. Zygomatic major. 
 12. Masseter. 13. Levator anguli oris. 14. Levator labii superioris. 15. Orbicularis oris. 16. 
 Buccinator. i6 / . Depressor anguli oris. 17. Depressor labii inferioris. 18. Levator labii inferi- 
 oris. 19. Sterno-mastoid. 20. Trapezius. 21. Digastric and stylo-hyoid. 22. Anterior belly of 
 digastric. 23. Pulley for tendon of digastric. 24, 24. Omo-hyoid. 25. Sterno-hyoid. 26. Thyro- 
 hyoid. 27. Mylo-hyoid. 28. Splenius capitis. 29. Splenius colli. 30. Levator anguli scapula'. 
 31. Scalenus posticus. 32. Scalenus anticus. 
 
 (2) a clavicular. Its size, location, and extensive nerve-supply make it the most 
 important muscle in the neck. These origins vary in size. In some cases you 
 will find the clavicular part very small, in other cases very large. The sternal 
 origin corresponds to the mastoid insertion ; the clavicular origin corresponds to 
 the occipital insertion. If you will follow the cleft between the two heads, it 
 will lead you to the junction between the occipital and mastoid. (Fig. 23.) 
 
 Stemo-mastoid slicatli ( Fig. 24) is formed by a delamination of the first layer 
 of deep cervical fascia. Cut through this sheath from end to end, just as you 
 would separate two muscles. In fact, as. pointed out in the preceding paragraph, 
 there are two muscles here, coalesced to form one. 
 
THE HEAD AND NECK. 
 
 5 1 
 
 NERVE-SUPPLY OF THE STERNO-MASTOID. This muscle, as you may now see, 
 receives numerous twigs from the spinal accessory nerve as this nerve is passing 
 through the muscle. It also receives nerves from the cervical plexus. Lift the 
 muscle very carefully, and demonstrate these nerves on your own work. 
 
 The Upper Attachments and Special Structures Formed by the First 
 Layer of Deep Cervical Fascia (Fig. 26). The same fascia that covers the 
 sterno-mastoid muscle is continued upward and forms special structures. You 
 will now dissect and study these. Cut along the lower margin of the jaw to the 
 symphysis rnenti. Avoid the facial artery and vein in front of the masseter 
 muscle. 
 
 Distribution of the Deep Cervical Fascia Above (Fig. 26). You now 
 see this fascia extending from the sterno-mastoid muscle to the masseter muscle 
 
 Capsule for 
 submaxil- 
 lary gland 
 
 Sheath for di- 
 gastric muscle 
 
 
 Sheath for the de- 
 pressors of the 
 hyoid bone 
 
 Mandibular attachment 
 
 Masseteric fascia 
 
 Parotid fascia 
 
 Stylo-mandibular 
 ligament 
 
 Sheath for the 
 sterno-mastoid 
 
 The carotid 
 sheath 
 
 Sterno-mastoid, 
 cut 
 
 Trapezius 
 
 Scalenus posticus 
 
 Scalenus medius 
 
 Scalenus anticus 
 
 Fi<;. 26. SCHEME OF UPPKR ATTACHMENTS OF AND SPECIAL NAMKS FOR DEEP CERVICAL FASCIA. 
 
 and parotid gland, forming their specific fasciae. You see it extending from the 
 styloid process to the jaw as the stylo-maxillary ligament ; you see it forming a 
 capsule for the submaxillary gland, and continuing forward to invest the anterior 
 belly of the digastric muscle. 
 
 The submaxillary gland is ensheathed by the first layer of deep cervical 
 fascia. Observe the facial vein passing in front of the gland ; and the facial 
 artery, perforating the deep fascia and passing behind the gland, or even through 
 the same. 
 
 WJiat nerves accompany the facial artery in its distribution to the face ? 
 
 Sympathetic branches the nervi molles. They produce blushing and pallor 
 of the face. 
 
52 PRACTICAL ANATOMY. 
 
 Are any other arteries accompanied by sympathetic nerves, in like manner, in this 
 region / 
 
 Yes, branches of the sympathetic accompany every branch of the external 
 carotid artery. Hyperaemia then may occur in the distribution of the temporal, 
 internal maxillary, and lingual arteries. The specific name for this physiological 
 hyperaemia on the face is " blushing." 
 
 Relations of the Sterno-cleido-mastoid Muscle. Review now carefully 
 your dissection, and learn the relations of this muscle thus far exposed. See if 
 your work shows the following points : 
 
 1. Did you demonstrate a sternal and clavicular origin and a mastoid and 
 occipital insertion of the muscle ? 
 
 2. Did you find crossing or lying upon the sheath of the muscle the external 
 jugular vein, the superficial cervical nerve, the great auricular nerve, and the 
 
 Stylo-hyoid ligament 
 
 BODY OF HYOID BONE 
 Thyro-hyoid ligament 
 
 Sterno-hyoid muscle 
 
 Omo-hyoid 
 
 Thyro-hyoid 
 
 Crioo-thyroid 
 Sterno-thyroid 
 
 ISTHMUS 
 
 TRACHEA 
 
 Thyro-hyoid membrane 
 
 Levator glandulee thyroide 
 
 THYROID CARTILAGE 
 
 PYRAMIDAL PROCESS OF THYROID BODY 
 
 LEFT LATERAL LOBE 
 
 FIG. 27. THYROID BODY, WITH MIDDLE LOBE AND LEVATOR MUSCLE. 
 
 mastoid branch or second small occipital nerve ? Did you see emerging through 
 the deep fascia, between the muscle and the trapezius, in the occipital triangle, 
 the spinal accessory nerve and all the superficial branches of the cervical plexus ? 
 Did you find the sheath of the muscle attached to the clavicle below ? Did you 
 find the same derived from the first layer of the deep cervical fascia and continu- 
 ous above with the masseteric and parotid fasciae ? with the stylo-maxillary liga- 
 ment? with the submaxillary and digastric fasciae? 
 
 Having done this, you may lift the muscle, observe its nerve-supply again, 
 from the spinal accessory and cervical plexus, and study the posterior relations. 
 
 Interior relations of t lie stcrno-clcido- mastoid muscle are : 
 
 1. The contents of the second layer of the deep cervical fascia. 
 
 2. The carotid sheath and its contents. This latter, you will remember, 
 belongs to the third layer of deep cervical fascia. 
 
THE HEAD AND NECK. 
 
 53 
 
 THE MUSCLES AND NERVES IN THE SECOND LAYER OF DEEP CERVICAL FASCIA. 
 
 1 . The sterno-hyoid and omo-Jiyoid. 
 
 2. The sterno-thyroid and thyro-hyoid. 
 
 3. The nerve-supply of these the ansa liypoglossal loop. (Figs. 23 and 29.) 
 Having turned the sterno-mastoid muscle and the fascia extending from it to 
 
 the mid-line of the neck aside, you expose the sterno-hyoid and the omo-hyoid 
 of this group. Figure 27 shows you the insertion of these two muscles con- 
 jointly into the lower border of the body of the hyoid bone. Cut these two 
 muscles one inch below this insertion, turn the lower part of the same forward 
 carefully, and note the nerve-supply. These muscles must be handled very care- 
 fully, in order to preserve them and also their nerves. The omo-hyoid arises 
 from the superior border of the scapula for one inch. The sterno-hyoid arises 
 
 Facial artery 
 
 Lingual artery 
 
 Supra-hyoid branch 
 Infra-hyoid branch 
 
 Superior laryngeal branch 
 
 Crico-thyroid branch 
 
 External carotid artery 
 
 Ascending pharyngeal artery 
 
 Internal carotid artery 
 
 Sterno-mastoid branch 
 
 Superior thyroid artery 
 
 Common carotid artery 
 
 Inferior thyroid artery 
 
 FIG. 28. SCHEME OF SUPERIOR THYROID ARTERY. 
 
 from the manubrium sterni. Trace out these origins at a later stage of your 
 work. 
 
 The sterno-cleido-thyroid is commonly called sterno-thyroid. This is inserted 
 into the oblique line of the ala of the thyroid cartilage. (Fig. 27.) From here 
 it is continued to the lower border of the outer third body, and the inner half of 
 the greater horn of the hyoid bone as the thyro-hyoid muscle. 
 
 The sterno-thyroid arises from the manubrium low down, and also from the 
 clavicle. (Fig. 30.) Detach this muscle from its insertion and turn it down 
 very carefully, and you will see the thyroid gland and its isthmus. 
 
 The thyro-hyoid removed by detaching it at its origin, you expose the thyro- 
 hyoid membrane, and see entering the same the superior laryngeal nerve and 
 artery. (Fig. 28.) 
 
lOkvury Body 
 
 12 Nerve, - 
 
 HypoglossaJ 
 
 (Nonus or9' K ofWUis.) 
 
 foSterno tljroul, Sthynut 
 ma-lyout . 
 
 FIG. 29. THE LOOP FORMED BY COMMUNICATING BRANCHES. 
 
 Sterno-thyroid 
 
 Triangularis 
 sterni 
 
 Sternal origin 
 of diaphragm 
 
 Costal origin 
 of diaphragm 
 
 Sterno-hyoid 
 
 Triangular!* 
 Bterni 
 
 Transveraalis abdominis 
 
 FIG. 30. 'I'm MTSCI.KS ATTACIIKD TO mi. HACK. 01 THE SIKRMM. 
 
 54 
 
THE HEAD AND NECK. 55 
 
 THE NERVE-SUPPLY TO THE DEPRESSOR MUSCLES OF THE HYOID BONE. The 
 group you have just dissected comes from a loop called the ansa hypoglossal. 
 The expression cervico-Jiypoglossal would be a better term, as it would seem, as 
 it expresses the derivation of the two elements composing the loop. (Fig. 29.) 
 
 The loop is formed by the descendens hypoglossi, anastomosing with two 
 communicating branches from the deep part of the cervical plexus. This loop 
 is formed on the front part of the carotid sheath. From it branches are given off 
 to the depressors of the hyoid bone. 
 
 1 . Give the boundaries of tJiat part of the neck most frequently operated on by 
 the surgeon. 
 
 Anteriorly, the mid- or mento-sternal line. Posteriorly, the anterior border 
 of the trapezius muscle. Superiorly, the mandible and masto-mandibular line. 
 Inferiorly, the clavicle and interclaviculaf ligament. 
 
 2. Name the cervical triangles and indicate tlieir importance. 
 
 The submaxillary or supra-hyoid triangle is bounded above by the mandible 
 and masto-mandibular line ; below, by the digastric and stylo-hyoid muscles ; 
 in front, by the mento-sternal line. It contains : (i) The facial vessels and their 
 sympathetic nerves ; (2) the submaxillary gland, its blood-vessels, nerves, and 
 capsule ; (3) the submental and mylo-hyoid vessels and nerves ; (4) the stylo- 
 mandibular ligament ; (5) the parotid gland and its contents ; (6) the vagus 
 nerve, internal jugular vein, internal and external carotid arteries. 
 
 The superior carotid triangle is bounded above by the digastric ; below, by 
 the omo-hyoid ; behind, by the sterno-mastoid muscle. It contains: (i) The 
 common carotid artery ; (2) the external carotid artery ; (3) the internal jugular 
 vein ; (4) the vagus ; (5) spinal accessory, and (6) sympathetic nerves. 
 
 3. The inferior carotid or tracheal triangle is bounded above by the omo- 
 hyoid, behind by the sterno-mastoid, in front by the mento-sternal line. It 
 contains : (i) The thyroid gland and its blood-supply ; (2) the trachea; (3) the 
 carotid sheath and contents ; (4) the inferior laryngeal nerve and inferior thyroid 
 vessels. 
 
 The three foregoing triangles lie anterior to the sterno-mastoid muscle. The 
 two following ones lie posterior to the sterno-mastoid muscle. 
 
 4. The occipital triangle is bounded in front by the sterno-mastoid, behind by 
 the trapezius, below by the omo-hyoid muscle. It contains: (i) The spinal 
 accessory nerve; (2) the descending branches of the cervical plexus; (3) the 
 transversalis colli vessels ; (4) a chain of lymphatic glands. 
 
 5. The subclavian triangle is bounded in front by the sterno-mastoid, above 
 by the omo-hyoid, below by the clavicle. It contains: (i) The subclavian 
 artery and vein ; (2) the brachial plexus ; (3) the external jugular vein ; (4) the 
 nerve to the subclavian muscle. 
 
 The student will please note that any arbitrary classification of contents is 
 impossible. Structures are found to form partial contents of several triangles. 
 The surgical triangles are to the modern surgeon about what totem poles would 
 be to the city council. 
 
 6. Name the structures in the superficial fascia of the neck. 
 
 (i) The platysma myoides muscle ; (2) the anterior, external, and posterior 
 jugular veins ; (3) the inframandibular branch of the seventh nerve, and (4) the 
 superficialis colli branch of the cervical plexus. 
 
 7. Name the layers of deep cervical fascia and give the contents of each. 
 The first layer surrounds the sterno-mastoid muscle. 
 
56 PRACTICAL ANATOMY. 
 
 The second layer surrounds the hyoid depressors and their vessels and. 
 nerves. 
 
 The third layer surrounds the larynx, trachea, thyroid, oesophagus, common 
 carotid artery, internal jugular vein, and vagus nerve. 
 
 The fourth layer covers the rectus capitis anticus major and minor muscles 
 and the longus colli. 
 
 8. What becomes of the first and second layers below? 
 They are attached to the clavicle and sternum. 
 
 9. Give the origin and insertion of the temporal muscle. 
 
 This muscle arises from the complete temporal ridge, from the temporal 
 aponeurosis, from the temporal fossa, and is inserted into the coronoid process 
 of the mandible. 
 
 10. Analyze the coronoid process. 
 
 This has an outer and an inner surface, an anterior and a posterior border, a 
 base, and an apex. 
 
 11. Of what does the complete temporal ridge consist ? 
 
 It consists of frontal, parietal, and temporal portions. The ridge has a 
 superior part for the attachment of the temporal fascia ; an inferior part for origin 
 of the muscle. 
 
 1 2. What do you find in grooves on the deep surface of the muscle next the bone ? 
 The deep temporal arteries branches of the internal maxillary artery for 
 
 the supply of the muscle. 
 
 1 3. Analyse the zygomatic arch and tell what you find under fke same. 
 
 The arcus zygomaticus is made up of the zygomatic processes of the malar 
 and temporal bones. It has a superior border, into which is inserted the tem- 
 poral fascia ; an outer surface, which is subcutaneous ; an inferior border and an 
 inner surface, which are occupied by the origin of the masseter muscle. Under 
 the arch are the coronoid and condylar processes of the mandible ; the sigmoid 
 notch, transmitting the masseteric vessels and nerves ; the external pterygoid 
 muscle ; and a considerable quantity of fatty connective tissue. 
 
 1 4. Describe the masseter muscle. 
 
 This muscle arises ( i ) from the inferior border, anterior two-thirds, and (2) from 
 the inner surface and posterior one-third of the lower border of the zygomatic 
 arch. It is inserted into the external surface of the ramus. It is covered on its 
 outer surface by the masseteric fascia, on which lie the pes anserinus, the parotid 
 gland in part, and Stenson's duct. 
 
 1 5 . Describe the stcrno-clcido-mastoid muscle. 
 
 This muscle has two origins a clavicular and a sternal ; and two insertions 
 a mastoid and an occipital. It extends obliquely across the neck, dividing this 
 region into an anterior and a posterior part. Its nerve-supply is from the spinal 
 accessory and deep branches from the cervical plexus. It lies on the carotid 
 sheath in part of its course, and along its posterior margin emerge the superficial 
 branches of the cervical plexus. (Fig. 22.) 
 
 1 6. Name t/ic superficial brandies of tlic cervical plexus. 
 
 The descending branches are the suprasternal, supraacromial, supra- 
 clavicular ; the ascending branches are the great auricular, the small occipital, 
 the lesser occipital, and the superficialis colli. 
 
 Quiz on the Structures in the Second Layer of Deep Cervical Fascia. 
 
 1. Name the depressor muscles of t/ic liyoid. 
 
 (i) The sterno-hyoid. (2) The omo-hyoid. (3) The sterno-thyroid. (4) The 
 thyro-hyoid. 
 
 2. /fo:,< are tlicsc muscles cnshcathcd and from elicit are they separated in front 
 and behind ? 
 
 They are ensheathed by a delamination of the second layer of deep cer- 
 
THE HEAD AND NECK. 57 
 
 vical fascia. In front of them is the first layer of deep cervical fascia, which 
 delaminates on the side of the neck to enclose the sterno-cleido-mastoid muscle. 
 Behind these structures are the members making up a group ensheathed by the 
 third layer of deep cervical fascia. 
 
 3. To what did you find the second layer of deep cervical fascia attached supe- 
 riorly and inferiorly ? 
 
 Superiorly it was attached to the hyoid bone ; inferiorly to the posterior 
 part of the clavicle and manubrium. 
 
 4. From what source do the depressors of the hyoid bone receive their nerve- 
 supply / 
 
 From the ansa hypoglossal loop, descendens, and communicans noni. 
 
 5 . Hoiv is the ansa liypoglossal loop formed ? 
 
 It is formed by the union of two branches from the deep cervical plexus 
 with one branch from the hypoglossal nerve. 
 
 6. What are these communicating nerves called ? 
 
 The one from the hypoglossal nerve is called the descendens Jiypoglossi ; the 
 two from the cervical plexus are called the communicantes hypoglossi, and the 
 loop formed by their union is the hypoglossal loop. 
 
 j. Have these communicating nerves any synonyms in anatomical literature ? 
 
 Yes, in the older texts they are called the descendens noni and communi- 
 cantes noni. Under the classification of cranial nerves by Willis, there were nine 
 pairs. The hypoglossal belonged to this ninth pair, hence the expressions nervus 
 nonus, nervus descendens noni, and nervi communicantes noni. 
 
 8. Can you think of a compound word that would be more specific, and at the 
 same time a more rational name than ansa hypoglossal ? 
 
 Yes, the compound cervico-hypoglossal would express the anatomical parties 
 to the compound, and would harmonize with our rules for writing compound 
 words, by which such relations should always be expressed. 
 
 9. Where did you find this loop ? 
 
 On the sheath containing the common carotid artery, pneumogastric nerve, 
 and internal jugular vein. (Fig. 31.) 
 
 The third layer of deep cervical fascia contains (Fig. 24) : 
 
 1. The thyroid body its nerve-supply and vessels. 
 
 2. The larynx and trachea, nerves and vessels. 
 
 3. The common carotid artery, vagus and internal jugular vein. 
 
 4. The external carotid artery and its branches in the neck. 
 
 5. The cervical stage of the internal carotid artery. 
 
 6. The hypoglossal nerve and its descending branch. 
 
 7. The cervical sympathetic cord and ganglia. 
 
 8. The arteries from the transverse aorta and their branches. 
 
 9. The phrenic nerve and anterior scalenus muscle. 
 
 10. The cervical plexus and its branches of origin. 
 
 1 1 . The bracldal plexus and its sheath. 
 
 12. The scaleni muscles anticus, medius, posticus. 
 
 Dissection. Remove the group of muscles in the second layer of the cervical 
 fascia, and examine the structures in the following order : 
 
 i. Thyroid Gland (Figs. 27 and 28). This derives its capsule from the con- 
 nective tissue in which it is developed. It has two lobes, connected by an isthmus. 
 Its arteries are a superior thyroid, which you will take to its origin, the external 
 carotid. This artery is attended by a vein. Note the anastomosis between the 
 5 
 
58 PRACTICAL ANATOMY. 
 
 superior thyroid and the inferior thyroid in the substance of the gland. The 
 inferior thyroid artery is a branch of the thyroid axis of the subclavian. Note 
 the crico-thyroid branch on the crico-thyroid membrane. Note also the superior 
 laryngeal artery, the same artery you found when you removed the thyro-hyoid 
 muscle : it accompanies the superior laryngeal nerve. The thyroid gland belongs 
 to the class of ductless structures, as the spleen, thymus, and suprarenal capsules. 
 An enlargement of this gland is called bronchocele ; in which case the isthmus 
 may be divided or one-half of the gland removed. The nerves to the thyroid 
 are of sympathetic derivation, from the middle and inferior cervical ganglia. The 
 inferior thyroid veins you will trace to the left brachio-cephalic vein. -The 
 superior and middle veins open into the internal jugular vein. These veins take 
 their origin in a plexus of veins especially large on the posterior part of the gland. 
 
 The carotid sheath is situated by the side of the trachea and larynx. In 
 this sheath are the common carotid artery internally, the internal jugular vein 
 externally, and the pneumogastric or vagus nerve between the two. 
 
 The internal jugular vein is formed by the confluence of the dural sinuses. 
 These sinuses receive their blood from the brain. The internal jugular veins are 
 made up at the jugular foramina at the base of the skull. The ninth, tenth, 
 and eleventh cranial nerves leave the cranial cavity with' the veins. In its course 
 down the neck the jugular vein receives the superior and middle thyroid 
 veins; and near their termination, they receive the external jugular veins. 
 Behind the clavicle, you will see the internal jugular vein on each side unite with 
 the subclavian vein. The result of this union is a large vein, called the 
 innominate or brachio-cephalic vein. These latter of each side unite with the 
 vena azygos major to form the descending vena cava. 
 
 The right common carotid artery begins on the right side, at the bifurcation 
 of the innominate artery. (Fig. 36.) This division occurs opposite the upper 
 margin of the thyroid cartilage. The result of the division gives us an internal 
 and an external carotid artery. Find to the inner side of the common carotid 
 artery the larynx, trachea, thyroid gland, inferior thyroid artery, and recurrent 
 laryngeal nerve. 
 
 The left common carotid artery on the left side differs from that on the 
 right as follows : It is given off in the thorax from the highest part of the arch of 
 the aorta. (Fig. 36.) It has the same relations in the neck as the right common 
 carotid. In the thorax the left common carotid artery is behind the manubrium 
 sterni, the origins of the sterno-thyroid and sterno-hyoid muscles, the left brachio- 
 cephalic or innominate vein, and the remains of the thymus gland. Behind the 
 artery are the trachea, oesophagus, and thoracic duct. Internal to the artery are 
 the innominate artery, the inferior thyroid veins, and remains of the thymus gland. 
 External to the artery are the vagus nerve, the left lung, and pleura. 
 
 The Glandulae Concatenatse. If the subject be tubercular, you may find 
 the deep cervical lymphatics enlarged. They lie with the internal jugular vein, 
 and may have contracted firm adhesions to the vein or artery or both. This 
 seems to be the tendency of glandular tissue : (i) to penetrate or (2) to embrace. 
 Instance the deep part of the parotid gland, penetrating the glenoid cavity and 
 embracing the styloid process too ; the anterior part of the same gland embraces. 
 in a V shape, the posterior border of the ramus of the mandible. Likewise, 
 these lymphatics, when enlarged, embrace vessels, a circumstance which makes 
 their removal often a very dangerous procedure. These glands you will find 
 forming a continuous chain from the base of the skull to the apex of the thorax, 
 where they are continuous with the mediastinai gland-chains. 
 
 The pneumogastric nerve, also called the vagus, or par vagum, lies between 
 I lie common carotid artery and internal jugular vein. Separate the connective 
 tissue between the vessels and find the nerve, deeply located. This n r\e gives 
 
77//1 HEAD AND NECK. 
 
 59 
 
 off in the neck (i) the superior laryngeal nerve to the larynx ; (2) the cervical 
 cardiac branches ; (3) the pharyngeal branches ; (4) the recurrent laryngeal 
 nerve. 
 
 For the present remember this : The pneumogastric supplies the organs of 
 voice and respiration with motion and sensation ; the organs of circulation and 
 digestion with motion only. 
 
 The internal carotid artery on each side begins at the bifurcation of the 
 common carotid. Find this bifurcation and see whether it is opposite the thyroid 
 cartilage or the hyoid bone. The internal carotid has four stages : 
 
 i. The ccrrical to the base of the skull, from the bifurcation. 
 
 Fiu. 31. VESSELS ANIJ NERVES OF THE HEAD AND NECK. 
 
 I. Subclavian artery. 2. Subclavian vein. 3, 3. Common carotid artery. 4. internal jugular vein. 
 5. Anterior jugular vein. 6. Omo-hyoid muscle. 7. Sterno-hyoid muscle. 8. Trunk of pneumo- 
 gastric nerve. 9. Hypo-glossal nerve. 10. Its terminal portion. if. Its descending branch. 
 12. Internal descending branch of cervical plexus. 13. Plexus formed by last two branches. 
 14. External carotid artery. 15. Superior thyroid artery and vein. 16. Lingual and facial arteries. 
 17. Facial artery and vein. 18. Occipital artery. 19. Anterior branches of the first four cervical 
 nerves. 20. Superior laryngeal nerve. 
 
 2. The petrosal in the carotid canal in the petrosa. 
 
 3. The cavernous in the cavernous sinus on the lingula. 
 
 4. The cci'cbral at the base of the brain in the cranium. 
 
 The cervical stage gives off no branches in the neck. The function of this 
 artery is to take blood to the brain, eye, and nose. It assists the vertebral in 
 forming the circle of Willis, by which circle the brain receives all its blood. 
 Blood returns from the brain by the internal jugular vein. 
 
 External Carotid Artery. This vessel begins at the bifurcation of the 
 common carotid artery just mentioned. In some tubercular cases you will find 
 
6o 
 
 PRACTICAL ANATOMY. 
 
 a large nest of enlarged glands here at the bifurcation. The following are the 
 branches of the external carotid artery and their attendants : 
 
 1. The superior thyroid artery, vein, nerve, lymphatic. 
 
 2. The lingual artery, vein, nerve, lymphatic. 
 
 3. "\\e facial artery , vein, nerve, lymphatic. 
 
 4. The occipital artery, vein, nerve, lymphatic. 
 
 5. The posterior auricular artery, vein, nerve, lymphatic. 
 
 6. The ascending pharyngeal artery, vein, nerve, lymphatic. 
 
 7. The temporal artery, vein, nerve, lymphatic. 
 
 8. The internal maxillary artery, vein, nerve, lymphatic. 
 
 NOTE. It has been pointed out in a foregoing paragraph that sympathetic 
 nerves accompany every branch of the external carotid artery. Morris shows 
 that the deep lymphatics of the head and neck roughly follow the course ot 
 the deep arteries, and finally terminate in the glandular concatenatae previously 
 described. Hence in vour dissection of the branches of the external carotid, 
 
 Falato-gloasus 
 
 Descending palatine arteri, 
 Palato-pharyngeus 
 
 TONSIL 
 
 Ascending palatine branch 
 
 of facial 
 Tonsillar branch of dorsalis 
 
 linguae 
 
 Tonsillar branch of facial 
 Stylo-glossuB - 
 
 Dorsalis lingua artery 
 
 Middle constrictor 
 HYPOGLOSSAL NERVE 
 
 Facial artery 
 
 Posterior belly of digastric 
 and stylo-hyoid 
 Supra-hyoid branch 
 
 SUP. LARYNGEAL K. 
 
 Infra-hyoid branch 
 
 Internal carotid artery 
 
 Ronnie artery 
 
 Q-enio-hyoid 
 Anterior belly 
 of digastric 
 
 ur /rry 
 Superior thyroid artery 
 
 External carotid artery 
 Common carotid arlrry 
 
 FlG. 32. SCH KM K OK TI1K LlNCJUAI. ARTKRY. 
 
 ,,: 
 
 you will remember you can always find the vein corresponding to the artc 
 the sympathetics may be found by treating the artery with ether and formaline ; 
 the lymphatic glands can only be demonstrated when enlarged by disease. As t<> 
 the lymphatic, I would urgently request the student to study carefully t 
 schematic drawings of these vessels by Professor F. R. Sherwood, in Mor 
 " Anatomy." 
 
 Caution. Never use a cutting instrument in dissecting arteries. The fore 
 or dissecting hook is all you need to divide the connective tissue. Handle veins 
 with gentle touch ; they are very easily ruptured. 
 
 Specific ] Dissection. The lingual artery: (i) find this vessel above the 
 greater horn of the hyoid bone ; (2) a little below, and running parallel with, the 
 hypoglossal nerve ; (3) passing behind the free margin of the hyo-glossus muscle 
 to the tongue. (Fig. 32.) 
 
 The Superior Thyroid Artery. (i) It is the first branch given off by the 
 external carotid ; (2) it goes to the upper part of the thyroid gland ; (3) it gives 
 off the superior laryngeal branch, which always accompanies the superior laryn- 
 
THE HI:, in AND XECK. 
 
 61 
 
 geal nerve ; (4) these structures, the superior laryngeal nerve and artery, pierce 
 the thyro-hyoid membrane ; (5) the anastomosis is feeble with the opposite side ; 
 free with the inferior laryngeal artery, and the distribution is to the gland and to 
 the depressor muscles of the hyoid bone that cover the gland. (Fig. 28.) 
 
 The facial artery: (i) often given off with the lingual; (2) note its deep 
 course behind the hypoglossal nerve, the stylo-hyoid muscle, the digastric 
 muscle, the parotid gland. It crosses the mandible in front of the masseter 
 muscle. Its specific sympathetic nerves are called nervi molles. (Fig. 17.) 
 
 The facial vein (Fig. 18), you will note, takes a superficial course. It lies in 
 
 Anterior branch of pos- 
 terior auricular 
 
 I'osterior branch of pos- 
 terior auricular 
 
 PAROTID GLAND- L_, 
 
 Sterno-mastoid, cut 
 
 Auricular branch of 
 occipital 
 
 Rectus capitis lateralia 
 
 Sl'IXAL ACCESSORY 
 
 NER VE 
 Posterior auricular 
 
 Internal jttfjit/itr n'in 
 Facial artery 
 
 J/Y/'OflLOSXAL y. 
 
 J.int/iirtl nrferi/ 
 
 PNEUMOOASTRIC 
 
 rio/' Itiiiroi'l 
 
 Common carotid 
 
 External branch of 
 occipital 
 
 Internal branch of 
 occipital 
 
 ComplexuB 
 
 Priceps cervicis 
 
 Superior oblique 
 Trachelo-mastoid, cut 
 Splenius capitis, cut 
 Meningeal brancln'x 
 
 Sterno-mastoid branch oj 
 occipital 
 
 Internal carotid 
 
 Sterno-mastoid 
 
 External carotid 
 Trapeziua 
 
 FIG. 33. SCHEME OF OCCIPITAL AND POSTERIOR AURICULAR ARTERIES. 
 
 front of the structures behind which the facial artery passes. It opens into the 
 external jugular vein. In your dissection show all the structures by which the 
 facial artery and vein are separated in their cervical stage. 
 Branches of the facial artery in the neck are : 
 
 1. To the stylo-hyoid, internal pterygoid, masseter, and buccinator. 
 
 2. Submaxillary branches four, to the submaxillary gland. 
 
 3. Submental artery to structures under the chin. 
 
 4. Tonsillar branches to the tonsil and tongue. 
 
 5. Ascending palatine branches to the soft palate. 
 
 The Occipital Artery (Fig. 33). (i) Find the hypoglossal nerve passing 
 
 
62 
 
 /'A' A CTICAL ANA TOM ) '. 
 
 under and behind and external to it, to gain its place in front of the internal and 
 external carotids ; (2) it passes behind the digastric, sterno-mastoid, splenius 
 capitis ; (3) it gives off the arteria princeps cervicis, which anastomoses with the 
 
 Stylo-, 
 
 INFERIOR DENTAL NERVE 
 CHORDA TYMPANI I / 
 FACIAL NERVE j / / 
 Internal maxillary artery 
 Stylo-hyoid, turned up 
 Digastricus, turned up 
 Temporal artery 
 
 glossus 
 
 S'lliinental artery 
 I Facial artery 
 
 MYLO-HYOID NERVE 
 
 LOWER JAW, TURNED UP 
 
 Posterior auricular artern 
 Internal jugular rein \ 
 
 SECOND CERVICAL 
 
 NERVE 
 
 SPINAL ACCESSORY 
 NERVE 
 
 Eectus capitis auticua major 
 Stylo-pharyngeus muscle 
 SUP. CER. GANGL. OF SYMPATHETIC 
 GLOSSO-PHAR. NERVE 
 Sterno-mastoid, reflected 
 Occipital artery 
 Internal carotid 
 Levator anguli scapulae 
 THIRD CERVIC. NERVE 
 DESCENDED HYPO- 
 GLOSS I NER VE 
 
 External carotid 
 Inferior constrictor 
 
 COMMl'N. HYPOGLOSS1 
 
 FOURTH CERV. NERVE 
 
 Ascending cervical artery 
 
 SPINAL ACCESSORY f 
 
 PHRENIC NER VE 
 
 Scalenus anticus 
 
 Levator anguli scapula: 
 
 FIFTH CERV. NER VE 
 Scalenus medius 
 CERVICAL I' LEX US 
 DESCJSNDENS BRA NCH 
 PNEVMOGA3TRIC / 
 
 NER VE 
 
 BRACHI.iL PLEXUS 
 
 (SIXTH CERVICAL) 
 
 Internal ja/jnlar rein 
 
 Superficial ceii'ical artery 
 
 Suprasca pnlar artery 
 
 Serratus magnus 
 
 Coraco-brachialis t \ 
 
 Suprascapular artery given uff front ttiiril 
 part nf snbclai inn 
 
 Posterior scapular artery 
 SUPRASCA PULA R NER VE 
 
 Humeral thoracic artery 
 
 SUB MA XI L LA R Y GA NGL10N 
 G USTA TOR Y NER VE 
 
 SUBMAXILLARY DUCT 
 SUBMAXILLARY GLAND 
 TONGUE 
 
 HYPOGLOS. NERVE 
 Rmiiite artery 
 
 Qenio-hyo-glossus 
 Sublinyual arteiy 
 
 Lingual artery 
 Artery affrcenitm 
 
 LOWER JAW 
 
 Genio-hyoid 
 
 Hyo-glossus 
 Liniinal artery 
 Ifyoid branch 
 Mylo-hyoid muscle 
 Thyro-hyoid membrane 
 SUPERIOR LARYN- 
 
 GEAL NERVE 
 Superior laryiigeal artery 
 Thyro-hyoid 
 Superior l/ii/njii! artery 
 Omo-hyoid 
 EX TERN A L LA R YN- 
 
 GEAL NERVE 
 THYROID GLAND 
 
 Sterno-hyoid 
 Coiiiiiitin carotid 
 Sterno-thyroid 
 Vertilnal artery 
 Inferior thyroid artery 
 . I nterinr j nyiilar vein 
 
 CLAVICLE 
 Verttbral rein 
 
 KRACIIIAL PLEXl 
 
 (SEVENTH CERVIC.) 
 
 Siilic/nrinii artery 
 
 Pectoralia major, 
 reflected 
 
 
 V Transverse cervical artery 
 Subclavius, reflected 
 
 BRACIIIAL I'LEXfS (EIGHTH CERVK'M.) 
 Pectoral branch of acromial thoracic arteiy 
 
 Posterior belly of omo-hyoid, drawn down 
 
 Pectoral a minor 
 
 Fic. 34. THE COMMON CAROTID, TIIK EXTKRNAI. AND I.MKKNAI. CAROTID, AND mi. Sruci \\i 
 
 AKIKRIKS OK TIIK RICHT SIDE AND THEIR BRANCHES. 
 (From a dissection by Dr. Alder Smith in the Museum of St. Bartholomew's Hospital.) 
 
 deep cervical, a branch of the superior intercostal, and the vertebral artery. 
 This anastomosis keeps up the collateral circulation, after ligation of the common 
 carotid artery. 
 
'/'//A' HI 'I. ID AND NECK. 63 
 
 The posterior auricular artery arises high. You will find it behind the 
 parotid gland. Trace it very close to the ear ; between the ear and the mastoid 
 process of the temporal bone. 
 
 The superficial temporal arteries are in the superficial fascia covering the 
 temporal muscle. They are attended by the sensory auriculo-temporal branches 
 of the fifth cranial nerve. Note the deep temporal vein piercing the temporal 
 fascia above the zygoma. (Fig. 18.) 
 
 The ascending pharyngeal you will find buried in connective tissue, lying 
 between the internal and external carotid arteries. It arises from the external 
 carotid near the bifurcation. It is the smallest branch of the external carotid. 
 It is distributed to the pharynx and meninges. 
 
 The internal maxillary will be dissected with the muscles of mastication 
 and the fifth cranial nerve. (Fig. 51.) 
 
 The Hypoglossal Nerve (Fig. 31). Find this nerve crossing the internal 
 and external carotid arteries a little above the bifurcation of the common carotid 
 artery. Note that this nerve lies a little distance above the lingual artery ; that 
 the artery crosses behind the hyo-glossus muscle, the nerve in front of the 
 muscle. The nerve gives off the following branches : 
 
 1. To the thyro-hyoid muscle. 
 
 2. To the stylo-glossus muscle. 
 
 3. To the hyo-glossus muscle. 
 
 4. To the genio-hyoid muscle. 
 
 5. To the genio-hyo-glossus muscle. 
 
 6. To the sterno-hyoid muscle. 
 
 7. To the omo-hyoid muscle. 
 
 8. To the sterno-thyroid muscle. 
 
 9. To the meninges ; recurrent branches. 
 
 All these branches, except the meningeals, you can readily trace out. This 
 nerve must not be mistaken for the superior laryngeal branch of the pneumo- 
 gastric. Now compare the two nerves in their relation to the carotid arteries on 
 your dissection. The result of section of this nerve will be considered when 
 you dissect the tongue and outline its complete nerve-supply. 
 
 Dissect the following muscles (Fig. 35) : 
 
 1. The digastric and its intermediary tendon. 
 
 2. The stylo-hyoid muscle. 
 
 3. The mylo-hyoid muscle. 
 
 4. The hyo-glossus muscle. 
 
 I. Find the insertion of the stylo-hyoid muscle into the lower border of the 
 body of the hyoid bone at the junction of the greater cornu and body of the 
 hyoid bone. Study the relation of the intermediary tendon of the digastric to 
 the aponeurosis of the stylo-hyoid muscle. Trace the origin of the stylo-hyoid 
 muscle to the base and outer surface of the styloid process of the temporal bone. 
 
 The Digastric has an anterior belly, that lies on the mylo-hyoid muscle, a 
 posterior belly, that lies under the stylo-hyoid muscle just found, an intermediary 
 tendon, and a suprahyoid aponeurosis. Carefully detach the anterior belly of 
 the digastric muscle from the digastric fossa of the mandible, and as you pull 
 this detached belly down, divide the connective tissue between this and the mylo- 
 hyoid muscle. Notice the nerve-supply to the anterior belly of the digastric 
 the mylo-hyoid branch of the inferior dental. The mylo-hyoid muscle is now 
 in full view since you removed the anterior belly of the digastric muscle. It 
 forms the floor of the mouth. It arises from the internal oblique line or mylo- 
 hyoid ridge on the inner surface of the body of the inferior maxilla. It is in- 
 serted into the mid-line of the neck into its fellow of the opposite side. This 
 muscle will be studied when you dissect the mouth and tongue. 
 
6 4 
 
 PR A CTICA L ANA TO. U ) . 
 
 The Hyo-glossus Muscle (Pig. 32). This is the muscle that separates 
 the hypoglossal nerve from the lingual artery. It arises from the body and 
 greater and lesser cornua of the hyoid bone. It passes to the tongue. It is the 
 most deeply located muscle in this region. 
 
 The great branches from the transverse part of the arch of the aorta may be 
 reviewed. In fact, you can not study them and their relations too much. The 
 innominate has been seen dividing into the right subclavian and right common 
 carotid. You may now dissect the branches of the subclavian artery and vein. 
 
 The Subclavian Artery and Vein. The subclavian artery has three stages : 
 
 1. From its beginning to the inner border of the scalenus anticus. 
 
 2. The artery behind the scalenus anticus. (Fig. 36.) 
 
 3. From the scalenus anticus to the lower border of first rib. 
 
 Stylo-glossus 
 
 Hyo-glossus 
 
 Mylo-hyoid 
 
 Anterior belly _ 
 of digastric 
 
 Raplie of mylo- - 
 byoid 
 
 Thyro-hyoid 
 Inferior constrictor 
 
 Anterior belly of 
 omo-hyoid 
 
 Sterno-hyoid 
 
 Sterno-thyroid - 
 
 Scalenus posticus 
 
 mft Posterior belly of 
 omo-hyoid 
 
 I.'K;. 3$. ANTKRIOR ANI> LATKKAI. CKKVICAJ. Mus< i i -. 
 
 Find the scalenus anticus muscle inserted into the scalene tubercle of the first 
 rib. In a groove in front of this tubercle find the ntbclavian vein ; behind the 
 tubercle find the subclavian artery. Behind the artery find the scalcnns incdius 
 muscle inserted into the first rib. Above the artery observe the anterior primary 
 divisions of the fifth, sixth, seventh, and eighth cervical nerves and first dorsal 
 nerve between the scalenus anticus and scalenus medius forming the brachial 
 plexus, 
 
 The subclavian arteries differ on the two sides ; the stages and branches, how- 
 ever, are the same in each as to name. The first stage of the left subclavian is 
 longer than the first stage of the right. 
 
 The right subclavian artery begins behind the right sterno-clavicular articula- 
 tion, at the bifurcation of the innominate artery. The artery lies very deeply. In 
 
THE HEAD AND NECK. 65 
 
 front of it are the skin, superficial fascia containing the platysma myoides, the 
 clavicular head of the sterno-cleido-mastoid muscle, the sterno-hyoid and sterno- 
 thyroid muscles. The phrenic nerve, the cardiac branches of the sympathetic 
 nerve, the vagus nerve, the vertebral and internal jugular veins, cross this artery. 
 Behind the artery is the neck of the first rib and the longus colli muscle and the 
 recurrent laryngeal nerve ; below the artery is the pleura, against wounding which 
 the greatest precautions should be taken in operations in this locality. 
 
 The left subclavian artery is longer than the right ; it does not arch outward 
 like the artery of the opposite side, but ascends vertically to the inner border of 
 the scalenus anticus muscle and is situated more deeply in the thorax. In front 
 
 PostSfu.ntii 
 AnlSfunai 
 
 FIG. 36. SCHEME FOR HEAD AND UPPER EXTREMITY. 
 
 of the artery are the lung and pleura, the vagus, phrenic, and cardiac nerves, the 
 left common carotid artery, internal jugular and vertebral veins, and left brachio- 
 cephalic vein, the sterno-hyoid, sterno-thyroid, and sterno-cleido-mastoid mus- 
 cles Behind the artery are the oesophagus, thoracic duct, inferior cervical gang- 
 lion, longus colli muscle, anH vertebral column. To the outer side of the artery 
 is the pleura ; to the inner side are the trachea, thoracic duct, and oesophagus. 
 
 Branches of the subclavian artery : 
 
 The internal mammary to anterior thoracic and abdominal walls. 
 
 The vertebral to the brain and spinal cord and vertebrae. 
 
 The superior intercostal to the first and second intercostal spaces. 
 
66 
 
 PR A CTICAL ANA TO. M ) . 
 
 The suprascatpular to the shoulder. 
 
 The inferior tliyroid to the thyroid gland. 
 
 The transvcrsalis colli. 
 
 1. The internal mammary (Fig. 36) is given off from the under part of 
 the first stage of the subclavian artery. Its course, branches, anastomoses, and 
 important relations are in the anterior thoracic walls, where you will find its 
 description when you dissect that part. 
 
 2. The suprascapular artery (Fig. 37) is attended by a vein and nerve of 
 the same name. It crosses the trunks of the brachial plexus, and is distributed 
 to the supra- and infraspinati muscles. 
 
 3. The Inferior Thyroid Artery. Trace this artery behind the common 
 carotid artery and sympathetic nerve. Very often the middle cervical ganglion 
 of the sympathetic nerve rests on the inferior thyroid artery. Usually the artery 
 
 Scalenus medius 
 
 Scale-ius anticua and 
 
 on it phrenic nerve 
 
 Transverse CITI ifal 
 artery 
 
 Suprascn/inlnr nrtf.ry 
 
 Sitbcliiiian artery 
 
 conn OF BRA CIHA L 
 
 f'LK.YUX, GIVING 
 OFF MUSCULO- 
 CUTAXEOUS ANT) 
 OUTER HEAD OF 
 MEDIAN NERVES 
 
 Axillary artery 
 
 IfUSCULO-SPIRA L 
 
 NKR \'E 
 
 T/ii/roitl mix 
 Internal j ugii/ar vein 
 
 Right common carotid 
 
 artery 
 
 PNEUMOGA8TR1C 
 NERVE 
 
 ieiK-fnirnt of 
 iniiominatf, vein 
 
 FIG. 37. THE SUBCLAVIAN VKSSKI.S. 
 (From a dissection in the Hunterian Museum.) 
 
 lies in front of the recurrent laryngeal nerve ; sometimes you will find the reverse 
 is true. In operations on the thyroid gland isolate (i) the recurrent laryngeal 
 nerve, (2) the sympathetic. 
 
 The branches of the inferior thyroid artery : 
 
 1. The inferior laryngcal to the larynx. 
 
 2. Trachcal branches to the trachea. 
 
 3. Utsopltagcal branches to the oesophagus. 
 
 4. Jtram/ies to the depressor muscles of the hyoid bone. 
 
 5. Ascending cervical brandies to the muscles of the neck. 
 
 The Superior Intercostal Artery (Fig. 39). This is given off from th< 
 second stage of the subclavian artery. It gives off a communicating branch t( 
 the first aortic intercostal, which you will find high in the thorax, when yoi 
 
THE HEAD AND NECK. 67 
 
 remove the pleura. The artery gives off its deep cervical branch, which inos- 
 culates with the arteria princcps cervicis, a branch of the occipital. The anasto- 
 mosis takes place between the complexus and semispinalis colli muscles. By 
 
 Right anterior cerebral 
 
 Internal carotid 
 Right posterior cerebral 
 
 Occipital 
 Princeps cervicis 
 
 External carotid 
 
 Superficial branch of princeps cervicis 
 Deep branch 
 
 Ascending cervical 
 
 Transverse cerrinil 
 Posterior scapular 
 Acromial branch 
 Subscapular brunch ,- 
 
 Supraspinous ^ 
 
 branch 
 
 Anterior circumflex 
 Infraspimrtii 
 
 branch 
 
 Posterior circumflex 
 
 Long thoracic 
 
 Subicapulai 
 
 Dorsal scapular 
 fnfraieapttlar 
 
 Subscapular 
 
 Left anterior cerebral 
 Anterior cotlMnunicutilig 
 
 Posterior comma n icatiny 
 Left posterior cerebral 
 
 Basilar 
 
 Anterior spinal 
 
 Superior thyroid 
 
 Inferinr (lit/mid 
 
 Common carotid 
 
 Thyroid axis 
 Superior inten-ostai 
 
 Illin>ltliliat<! 
 
 '<>! intrrriis'iil 
 I.H't ennnnon carotid 
 LfJ't subclavinn 
 tjhiirt thoracic 
 
 lii/ernal mammary 
 
 Anterior intercostal 
 
 I-'irxt aortic inter- 
 costal 
 
 Second aor/ic inter- 
 com tal 
 
 A n lerior in tcrcosla I 
 
 Third aortic inter- 
 costal 
 
 FIG. 38. THE COLLATERAL CIRCULATION AFTER LIGATURE OF THE COMMON CAROTID AND 
 
 Si ix I.AVIAN ARTERIES. 
 (A ligature is placed on the common carotid and on the third portion of the subclavian artery.) 
 
 this anastomosis the collateral circulation is carried on after ligature of the 
 common carotid artery. (Figs. 38, 39, and 40.) 
 
 The vertebral artery (Fig. 40) is given off from the second stage of the 
 
68 
 
 PRACTICAL ANATOMY. 
 
 subclavian. It passes through the foramina in the transverse processes of the 
 cervical vertebrae, except the lower two, and through the foramen magnum, in 
 the occipital bone, to assist the internal carotid artery in forming, by anasto- 
 mosis, the circle of Willis. The artery is attended by a sympathetic plexus of 
 nerves from the inferior cervical ganglion. The artery is found lying in the 
 vertebral groove, at the junction of the lateral mass and posterior arch of the 
 atlas in the suboccipital triangle, at the base of the skull. This triangle is 
 bounded by the superior and inferior oblique and rectus capitis posticus major 
 muscles. The roof of the triangle is the complexus muscle. 
 Branches of the vertebral artery are as follows : 
 
 1. Muscular branches to the deep muscles of the neck. 
 
 2. Lateral spinal arteries to the spinal cord and meninges ; the bodies of the 
 vertebrae also receive blood from these branches. 
 
 Scalenus anticus muscle 
 
 Deep cervical branch 
 
 FIRST DORSAL NERVE 
 
 FIRST INTERCOSTAL 
 NER VE 
 
 Subclavian artery 
 
 SECONH I \TKRCOSTAL 
 
 Anterior intercostal 
 
 artery 
 
 THIRD INTER- 
 COSTAL NERVE 
 
 Anterior intercostal 
 artery 
 
 Intercostal vessels qf 
 third space 
 
 SYMPA THE TIC 
 SER VE 
 
 INFERIOR CERVI- 
 CAL GANGLION 
 
 } Superior intercostal 
 artery 
 
 Arter ia aberrant 
 
 Branch from first aortic 
 intercostal 
 
 Arteria aberrant 
 
 Fint aortic intercostal 
 
 artery 
 
 Second aortic intercostal 
 artery 
 
 Intei costal vessels of fourth space 
 
 FIG. 39. SCHEME OF THE SUPERIOR INTERCOSTAL ARTERY. 
 
 3. Anterior and posterior spinal branches that may be well seen when y( 
 dissect the cord. 
 
 4. Posterior inferior ccrcbellar arteries. These are the largest arteries given off 
 from the vertebral. They will be studied when we consider the structures seen 
 on removing the brain. The two vertebral arteries unite, within the cranium, to 
 form the basilar artery. This artery will be studied when you remove the 
 brain. 
 
 The transversalis colli is a branch of the thyroid axis. It gives off the 
 posterior scapular artery, by which collateral circulation is established with the 
 subscapular branch of the axillary artery in cases of ligation of the third stage 
 of the subclavian artery. (Figs. 38, 39, and 40.) 
 
 The scaleni muscles are three in number. You have already studied their 
 insertion into the first and second ribs. You will now review the relation be- 
 
 
THE HEAD AND NECK. 
 
 69 
 
 tween the subclavian vein and artery on the outer surface of the first rib. You 
 will again see the nerves that are to form the brachial plexus coming through 
 between the scalenus anticus and scalenus medius muscles above the subclavian 
 artery. You will find the phrenic nerve lying on the anterior surface of the 
 scalenus anticus muscle. You will in time trace it between the subclavian vein 
 and artery into the thorax, down in front of the root of the lung, to the diaphragm, 
 and all the serous membranes continging the diaphragm, for distribution. 
 
 Origin of the Scaleni Muscles. To aid the memory, remember the num- 
 erals 3, 6, 3. The scalenus anticus arises from the anterior tubercles of the lower 
 three transverse processes ; the scalenus medius from the lower six ; the scale- 
 nus posticus from the lower three. The last two arise from posterior tubercles. 
 Remember, scarcely any two dissections will show exactly the same origin ; 
 
 I!i</ht posterior cerebral artery 
 
 Left posterior cerebral artery 
 
 Basilar artery 
 
 BASILAR PROCESS, OCCIPITAL BONE 
 
 Intracranial portion of vertebral artery 
 Reetus capitis lateralis muscle 
 
 FIRST CER VIC A L NER VE 
 
 Commencement of vertebral vein 
 
 SECOND CERVICAL NERVE 
 
 Vertebral plexus of reins 
 
 THIRD CERVICAL NERVE 
 
 Vertebral portion of vertebral artery 
 FOURTH CERVICAL NERVE 
 
 Vertebral plexus of veins 
 FIFTH CERVICAL NERVE 
 
 SIXTH CERVICAL NERVE 
 
 Inferior thyroid artery 
 
 Longus colli muBde 
 
 Cervical portion of vertebral artery 
 
 Internal jugular vein, hooked a little 
 aside 
 
 Vertebral vein, cut 
 Subclavian artery 
 
 Right and left svpe- 
 
 * rior cerebellur 
 
 arteries 
 
 OCCIPITAL BONE 
 
 Bectus capUis pos- 
 ticus minor mus- 
 cle 
 
 Occipital portion of vertebral artery 
 
 Arleria princejm cerrlcis 
 
 Semispiualis colli muscle 
 
 Deep cervical artery 
 
 Scalenus anticus muscle, cut 
 Thyroid axis, hooked a little aside 
 Subclarian vein 
 
 FIG. 40. SCI! KM K OK THK YKRTKUKA1, ARTKRY. 
 
 The internal jugular and vertebral veins are hooked aside to expose the artery. 
 
 hence it is, scarcely any two authors will give the origin of these muscles alike. 
 The foregoing is a general average and easily remembered 3, 6, 3. 
 
 The Levator Anguli Scapulae Muscle. It is necessary to have exact 
 knowledge of this muscle, to understand your dissection of the plexuses. This 
 muscle arises from the posterior tubercles of the transverse processes of the 
 upper three. You will find the tendons of origin of this muscle becoming fleshy. 
 They will unite to form a flat muscle, two inches broad. This muscle will be 
 inserted into the middle lip of the vertebral border of the scapula, from the 
 superior angle to the vertebral end of the scapular spine. Find its nerve-supply 
 coming from the cervical plexus. 
 
70 PRACTICAL ANATOMY. 
 
 1. Locate tlie thyroid gland. 
 
 It is in the third layer of deep cervical fascia. It embraces the cricoid car- 
 tilage of the larynx and the upper part of the trachea. 
 
 2. From illicit source docs the tJiyroid gland receive its blood / 
 
 From the superior thyroid artery, a branch of the external carotid, and from 
 the inferior thyroid, a branch of the thyroid axis of the subclavian artery. 
 
 3. Does anastomosis occur between tlie right and left thvroid arteries / 
 Yes ; this occurs, but very scantily, in the isthmus. 
 
 4. Does the thyroid ever receive blood from any other source / 
 
 Yes ; it may receive an artery either from the arch of the aorta or from the 
 innominate artery, called the thyroidea ima. 
 
 5. From what source does the thyroid gland derive its nerve-stepply ? 
 From the middle cervical ganglion of the sympathetic. 
 
 6. By ivhat structures is the thyroid gland covered ? 
 
 By the skin, superficial fascia, first and second layers of deep fascia, the latter 
 containing the depressor muscles of the hyoid bone. 
 
 7. Give contents of the carotid sheath and locate the same. 
 
 It contains the common carotid artery, the pneumogastric or vagus nerve, and 
 the internal jugular vein. On the sheath lies the ansa-hypoglossal loop, from 
 which the depressor muscles of the hyoid bone are innervated. The sheath is 
 in the third layer of deep cervical fascia, and crossed near its middle third by the 
 omo-hyoid muscle. 
 
 8. Explain the common carotid artery. 
 
 It lies to the inner side of the sheath, very near the larynx and trachea. To 
 its outer side is the internal jugular vein. It is crossed by the ansa-hypoglossal 
 loop and omo-hyoid muscle. On the right side it begins at the bifurcation of the 
 innominate artery, behind the sterno-clavicular joint ; on the left side it begins 
 at the arch of the aorta. The common carotid arteries end near the hyoid bone 
 by dividing into the external and internal carotids, having given off no branches 
 in their course. 
 
 9. Describe the internal carotid artery. 
 
 It begins at the bifurcation of the common carotid, and has four stages : 
 
 (1) The cervical stage to the base of the skull, where it enters the temporal bone ; 
 
 (2) the petrosal stage, where it passes through the carotid canal in the petrosal 
 part of the temporal bone ; (3) the cavernous stage, where it lies in the caver- 
 nous sinus of the dura mater, by the side of the body of the sphenoid bone ; 
 (4) the cerebral stage, where it comes through the dura mater to give off its 
 terminal branches to the brain. 
 
 10. Name the branches given off from tJie intracranial portion of tJie internal 
 carotid. 
 
 (i) It contributes the anterior cerebral, the middle cerebral, and the posterior 
 communicating to the circle of Willis. (2) It gives off the ophthalmic artery 
 for the supply of the orbit and its contents, the ethmoidal cells and the inner and 
 outer nose in part. (3) It gives off the anterior meningeal arteries to the dura 
 of the anterior fossa of the base of the skull. (4) It supplies the Gasserian 
 ganglion. 
 
 1 1. \Vliat brandies are given off from the petrosal stage ? 
 
 (i) The Vidian, which is said to anastomose with the Vidian branch of the 
 internal maxillary. (2) The tympanic, which goes to the middle ear and anas- 
 tomoses with the tympanic branches of the internal maxillary and stylo-mastoid 
 arteries. 
 
 12. Name all the structures between the sh'/i and the internal carotid one-half 
 of an incJi below flic base of tlie skull. 
 
 (i) The parotid gland ; (2) posterior belly of the digastric muscle ; (3) stylo- 
 
THE HEAD AND NECK. 7 , 
 
 hyoid muscle ; (4) hypoglossal nerve ; (5) posterior auricular and occipital 
 arteries ; (6) external carotid artery ; (7) stylo-glossus and stylo-pharyngeus 
 muscles ; (8) stylo-hyoid ligament and pharyngeal branch of the pneumogastric 
 nerve. 
 
 13. Name the branches of the external carotid artery and indicate the territorv 
 its brandies supply. 
 
 By the posterior auricular, occipital, and temporal branches it supplies the 
 scalp ; by the superior thyroid it supplies the thyroid gland and the structures 
 covering the same ; by the facial it supplies the dermal muscles of expression 
 and the skin covering them ; by the lingual it supplies the tongue ; by the 
 internal maxillary it supplies the teeth, the muscles of mastication, the palate, 
 the antrum of Highmore, the nasal fossae, and the dura mater ; by its ascending 
 pharyngeal branch it supplies the pharynx. 
 
 14. Where may you compress the facial artery? 
 
 In front of the masseter muscle on the body of the mandible, 
 i 5 . Where may you find the lingual artery for ligation ? 
 Above the greater cornu of the hyoid bone. 
 
 1 6. Give names of four important structures in front of the facial artery. 
 
 (i) Hypoglossal nerve; (2) digastric muscle; (3) stylo-hyoid muscle; (4) 
 submaxillary gland. The fascia and skin lie in front of these four structures. 
 
 1 7. Name an important branch of the superior thyroid artery found in your 
 dissection. 
 
 The superior laryngeal, which, in company with the superior laryngeal branch 
 of the pneumogastric nerve, piercing the thyro-hyoid membrane to supply the 
 larynx. 
 
 1 8. Where is the internal jugular vein made up ? 
 
 In the jugular foramen, by the confluence directly and indirectly of the dural 
 sinuses. The ninth, tenth, and eleventh nerves also pass out through this 
 foramen. 
 
 19. Does the internal jugular vein receive any tributaries in its course? 
 
 Yes ; the lingual, facial, superior and middle thyroid, and pharyngeal. This 
 vein unites with the subclavian to form the innominate or brachio-cephalic vein. 
 
 20. What branches does the pneumogastric nerve give off in the neck ? 
 
 (i) The pharyngeal, to help form the pharyngeal plexus; (2) the superior 
 and recurrent laryngeal for the supply of the larynx ; (3) the cervical cardiac 
 branches to assist in forming the cardiac plexus. 
 
 2 1 . Where did you find the superior laryngeal nerve, and in company with 
 zvhat was it ? 
 
 Piercing and lying on the thyro-hyoid membrane with the superior laryngeal 
 branch of the superior thyroid artery. 
 
 22. What does the superior laryngeal nerve supply ? 
 
 The mucous membrane of the larynx and trachea by its internal branch ; 
 the crico-thyroid muscle by its external branch. 
 
 23. Where did you find the recurrent given off and distributed / 
 
 It was given off from the vagus on the right side, just after this nerve crossed 
 the subclavian artery. The nerve then passed upward and inward, behind the 
 subclavian artery, gained the space next the trachea, and followed the same to 
 the larynx. It supplies branches to all the muscles of the larynx except the 
 crico-thyroid ; it supplies, also, branches to the trachea and oesophagus. 
 
 24. What are the glandules concatenates and what is their surgical importance f 
 The deep cervical glands accompanying the internal jugular vein ; they extend 
 
 from the base of the skull to the root of the neck. Their importance surgically 
 is the operation for their removal. 
 
 25. Name the structures a surgeon should avoid injuring in (his operation. 
 
72 PRACTICAL ANATOMY. 
 
 (i) The carotid artery; (2) the internal jugular vein ; (3) the vagus nerve ; 
 (4) the cervical sympathetic, behind the carotid sheath ; (5) the recurrent 
 laryngeal nerve ; (6) the apex of the parietal pleura. 
 
 26. Name the branches of the hypoglossal nerve. 
 
 (i) A communicating branch to the cervical plexus to form the ansa hypo- 
 glossal loop. (2) Muscular branches to the sterno-hyoid, omo-hyoid, sterno- 
 thyroid, thyro-hyoid, stylo-glossus, hyo-glossus, and genio-hyo-glossus. 
 
 27. Explain the digastric muscle. 
 
 It has an anterior belly, a posterior belly, an intermediary tendon. The 
 attachments are the digastric groove of the temporal bone and the digastric fossa 
 of the mandible, the body of the hyoid bone. The action of the muscle depends 
 on its fixed point. When the depressor muscles of the hyoid bone fix this bone, 
 then the digastric depresses the mandible. In the act of swallowing, the hyoid 
 bone is elevated by the digastric and its probably dismembered synergist, the 
 stylo-hyoid. The seventh nerve supplies the posterior belly ; the mylo-hyoid 
 branch of the inferior dental of the fifth nerve, the anterior belly of the digastric. 
 
 28. What important nerve did you find on the outer part of the liyo-glossus 
 muscle ? 
 
 The hypoglossal, the motor nerve of the tongue. The lingual artery passes 
 behind the muscle. 
 
 29. Explain fidly the Jiyo-glossus muscle. 
 
 The action of the muscle is to make the back of the tongue convex, and to 
 retract the tongue. The origin is from the outer third of the anterior part of 
 the body of the hyoid bone and from both the greater and lesser cornua. The 
 muscle is inserted into the side of the tongue. 
 
 30. Name the arteries you found arising from the transverse part of the aortic- 
 arch. 
 
 The innominate artery on the right side ; the left common carotid and left 
 subclavian on the left side. 
 
 3 1 . Name the stages of the subclavian artery. 
 
 The first stage is internal to the scalenus anticus muscle ; the second stage 
 is behind the muscle ; the third stage is from the outer margin of the muscle to 
 the lower border of the first rib. 
 
 32. Name the branches of the subclavian artery. 
 
 (i) The internal mammary ; (2) the vertebral ; (3) the suprascapular ; (4) the 
 superior intercostal ; (5) the transversalis colli. 
 
 33. Where would you find for ligation the internal mammary artery / 
 
 A finger's breadth to the right or left of the sternum, in the third or fourth 
 intercostal space. 
 
 34. How does the vertebral artery get to the base of the brain / 
 
 It passes through foramina in the transverse processes of the cervic 
 vertebrae, and through the foramen magnum. 
 
 35. If the common carotid artery were ligated, by w/iat tivo collateral channels 
 ivould the blood circulate f 
 
 First, through the thyroid arch. Second, through the occipito-intercostal 
 arch. 
 
 36. Hoiv is the thyroid areJi formed ? 
 
 By anastomosis between the superior thyroid branch of the external carotid 
 artery and the inferior thyroid branch of the subclavian artery. (Fig. 38.) 
 
 37. Hoiv is the occipito-intercostal arch formed / 
 
 By an anastomosis between the princeps cervicis of the occipital, and the deep 
 cervical branch of the superior intercostal artery. 
 
 38. WJiat, if any, changes occur in these collateral arches / 
 
 They become much larger, since growth is the correlative of function. 
 
THE HEAD AND NECK. 73 
 
 39. In dissection, where do you find the occipito-intercostal air/i / 
 Between the semi-spinalis colli and complexus muscles. (Fig. 40.) 
 
 40. Define the word scalene and name the scalene muscles. 
 
 A triangular figure of unequal sides. The scalenus anticus, medius, and pos- 
 ticus. 
 
 41. Where are these muscles inserted ? 
 
 The anticus is inserted into the scalene tubercle of the first rib ; the medius 
 into the first rib ; the posticus into the second rib. The two are separated by 
 the subclavian groove for the subclavian artery. 
 
 42. Give the origin of the scalene muscles according to j, 6, j. 
 
 The scalenus anticus arises from the anterior tubercles of the transverse pro- 
 cesses of the lower three ( j) ; the medius from the posterior tubercles of the 
 lower six (6) ; the posticus from the posterior tubercles of the lower three ( j) 
 cervical vertebrae. 
 
 The cervical plexus, to be of technical as well as practical value to the 
 student, should be studied in the following analytical manner, by question and 
 answer, before dissection : 
 
 1 . Why is this plexus called cervical ? 
 
 On account of its derivation from cervical nerves, its location and major 
 distribution in the neck. 
 
 2. Where is this plexus situated ? 
 
 It is situated opposite the four upper cervical vertebrae. It is covered by the 
 sterno-cleido-mastoid muscle. It lies on or is supported by two muscles whose 
 origin we have just seen the scalenus medius and levator anguli scapulae. 
 
 3. Is this plexus deeply located? 
 
 No, it is the most superficially located of all the somatic plexuses. It 
 emerges from under the posterior border of the sterno-cleido-mastoid muscle 
 midway between the origin and insertion of this muscle, regardless of length of 
 neck, into the occipital triangle. 
 
 4. What seems to be the predominating' function or physiological importance of 
 the cervical plexus f 
 
 To aid primarily and secondarily in respiration, as follows : It furnishes the 
 phrenic nerve. This nerve supplies the diaphragm with motor influence ; it 
 supplies the serous membranes investing the diaphragm with sensation ; through 
 its relation to the sympathetic it reaches all the abdominal organs that contihge 
 the diaphragm. It communicates with the nerve to the subclavius muscle, and, 
 according to Hilton's law, must send articular branches to the sterno-clavicular 
 articulation. (See Hilton's law.) It communicates with the intercostals, by which 
 the ribs are moved in re'spiration. It communicates with the ansa hypoglossal 
 loop, by which the depressor muscles of the hyoid bone are innervated. 
 
 The cervical plexus furnishes communicating branches to the formation of 
 the hypoglossal loop. The hypoglossal nerve is the motor nerve to the tongue. 
 This nerve unites, by its descendens hypoglossi, with the two communicantes 
 hypoglossi, previously referred to, and in this way harmony is established 
 between the nerve that moves the tongue and the nerve that moves the muscles 
 that depress the hyoid bone, on which the tongue rests. 
 
 The cervical plexus sends motor nerves to the following muscles : sterno- 
 cleido-mastoid, scaleni, the trapezius, the levator anguli scapulae ; through its 
 descending cutaneous branches it supplies the skin over the insertion of these 
 muscles. These muscles all are accessory to respiration in asthma and other 
 diseased conditions requiring more than ordinary tranquil respiration. 
 
 The cervical plexus communicates with the pneumogastric, and this nerve 
 supplies the organs of voice and respiration with motion and sensation. In fine, 
 the function of the cervical plexus very clearly is to innervate the muscles of 
 6 
 
74 PRACTICAL ANATOMY. 
 
 respiration, and to supply the serous membranes associated with the respiratory 
 movement. 
 
 5 . How is the cervical plexus fanned / 
 
 It is formed by the union of the anterior primary divisions of the first, 
 second, third, and fourth cervical nerves. The communications of the upper 
 two nerves of this plexus are with nerves whose function has to do with 
 respiration, with expenditure of air, or with movement of the tongue the 
 sympathetic, the pneumogastric, the hypoglossal. The communications of the 
 lower two nerves are with the. brachial plexus. 
 
 6. Explain the distribution of the branches of the cervical plexus. 
 
 This is rational, and must be studied in a philosophical light to be remem- 
 bered and appreciated. Remember, it is one thing to commit to memory a 
 statistical table of the branches of distribution of this plexus, as is often done ; 
 and quite another thing to understand the rationale of a distribution. I desire 
 you to learn the latter first. 
 
 1 . This plexus has muscular branches which supply muscles that, without a 
 single exception, have two well-defined actions. 
 
 2. This plexus has branches that supply the skin or serous membrane, as 
 the case may be, covering these muscles. This is in accordance with Hilton's 
 law, and applies to the articulations, and also to the skin covering the most 
 extensive origin or insertion of the muscle. 
 
 3. This plexus has communicating branches, like any other plexus. One 
 set of communicating branches is to those muscles which act synergistically to 
 produce the muscular movements of respiration directly. Another set is to 
 communicate with nerves that supply parts dependent on respiration. 
 
 The muscles supplied are as follows : 
 
 1 . The platysma myoides acts toward clavicle or toward mandible. 
 
 2. The sterno-cleido-mastoid acts on the head or the thorax. 
 
 3. The scaleni act on the ribs or on the neck. 
 
 4. The levator anguli scapulae acts on scapula or neck. 
 
 5. The recti capitis antici major and minor act on head or neck. 
 
 6. The trapezius acts on head or shoulder girdle. 
 
 7. The diaphragm acts on ribs and on cervical fascia. 
 
 8. Sterno-hyoid acts toward sternum or toward hyoid bone. 
 
 9. Omo-hyoid acts toward scapula or to the hyoid bone. 
 
 10. Thyro-hyoid and sterno-thyroid toward sternum or hyoid. 
 
 1 1. Genio-hyoid acts toward mandible or toward hyoid. 
 
 12. Genio-hyo-glossus acts forward and backward. 
 
 13. Stylo-glossus acts to or from the tongue. 
 
 14. Hyo-glossus acts to or from the hyoid. 
 
 The serous membranes and integument supplied in these areas : 
 
 1. The pleura;, pericardium, peritoneum. 
 
 2. Skin over the pectoralis major and acromion and clavicle. 
 
 3. Skin over the depressors of the hyoid bone. 
 
 4. Skin over the genial muscles. 
 
 5. Skin over the upper ends of sterno-mastoid, trapezius, and scaleni. 
 
 The phrenic supplies all the serous membranes. The descending branches of 
 the plexus supply the skin over the anterior part of the upper thorax and over 
 the shoulder. The lesser and second occipital supply the skin over the sterno- 
 mastoid and trapezius. (Fig. 43.) The superficial cervical supplies the whole 
 front of the neck and the region under the chin. 
 
 The ascending and descending branches, then, of the cutaneous, sensory, or 
 superficial nerves of the plexus are thus accounted for. The supraclavicular, 
 suprasternal, and supraacromial are the descending ; the superficial cervical is a 
 
THE HEAD AND NECK. 
 
 75 
 
 transverse branch ; the great auricular, small occipital, and lesser or second 
 occipital are ascending. These branches had to undergo this very distribution 
 to carry out the scheme of distribution of the cervical nerves a scheme we 
 everywhere invoke when we would account for sensory nerve distribution. 
 
 The communicating branches are : 
 
 i. Extrinsic, as your dissection should show, with the auriculo-temporal, 
 the facial, the intercostals, the circumflex, and the great occipital. 
 
 FIG. 41. SCHEME OF THE CERVICAL PLEXUS. 
 Note the loops by which one nerve communicates with the next. 
 
 2. Intrinsic : with the hypoglossal, sympathetic, pneumogastric, spinal acces- 
 sory, and brachial plexus, for reasons set forth in a foregoing paragraph. 
 
 External and Internal Series of Muscular Branches of the Cervical 
 Plexus. The scalenus medius, trapezius, levator anguli scapulae, and sterno- 
 cleido-mastoid are, according to the time-honored classification, given as the 
 external series, while all the remaining muscles would naturally fall to the internal 
 
7 6 
 
 PRACTICAL ANATOMY. 
 
 series. It may be said, with all deference, that this classification is categorical only. 
 It rests on no basis of physiology, philosophy, rationalism, or even sense ; it is 
 categorical only. It belongs to that part of our nomenclature that had its origin 
 in fanciful creations, and in location only, like sphenoid, ethmoid, and external 
 iliac. It is tolerated in anatomy and revered on account of its antiquity. 
 
 The branches of the cervical plexus, tabulated according to the prevailing- 
 custom, but carried out to their distribution to show that these nerves are 
 physiologically associated, directly or indirectly, with respiration : 
 
 Filament 
 fCtrv. 
 
 J.Ttiree Sub -scapular J\/erves. 
 2. Internal JTnt.T'horacu: 
 
 Mufculo-cutaneeus 
 
 Median. 
 
 at 
 
 Internal -cutarwoiif 
 Lesser Internal cutaneous 
 
 ffom fitter's CombenclofJnatomu 
 
 FIG. 42. SCHEME OF THE BRACHIAL PLEXUS. 
 Note the acute angles characterizing the union of nerves. 
 
 SUPERFICIAL BRANCHES. (Fie. 43.) 
 
 ASCENDING. (i) Second occipital supplies the skin over the mastoid insertion of 
 the sterno-cleido-mastoid. (2) Lesser occipital supplies the skin of the scalp 
 over the occipital origin of the trapezius, and over the greater insertion of 
 the sterno-mastoid. (3) Great auricular supplies the skin over the facial 
 part of the platysma and parotid gland, and over the insertions of the 
 three dermal muscles inserted into the external ear. (4) Superficial cervical 
 supplies the skin over the origin of the muscles arising from the genial 
 tubercles, and over the muscles inserted into the hyoid bone. 
 
THE HEAD AND NECK. 77 
 
 DESCENDING. (i) Suprasternal supplies the skin over the origins of the sterno- 
 mastoid, sterno-hyoid, sterno-thyroid. (2) Supraclavicular supplies the 
 skin over the thoracic part of the platysma, and over the costal attachments 
 of the scaleni. (3) Supraacromial supplies the skin over the omo-hyoid and 
 over the clavicular and scapular insertions of the trapezius. 
 
 DEEP BRANCHES. 
 
 INTERNAL. (i) Communicating branches to the pneumogastric, hypoglossal, 
 sympathetic. (2) Muscular branches to the rectus capitis anticus major and 
 minor, and rectus capitis lateralis, and longus colli. (3) Commumcans 
 hypoglossi, two cervical branches that unite with the descendens hypoglossi 
 to form the ansa hypoglossal loop, for the supply of the depressor muscles 
 of the hyoid bone. (4) The phrenic a mixed nerve that supplies the 
 diaphragm and the diaphragmatic parts of the pericardium, pleurae, and 
 peritoneum. 
 
 EXTERNAL. (i) Communicating branches to the spinal accessory nerve, in the 
 
 trapezius and under the sterno-cleido-mastoid muscle. (2) Muscular to the 
 
 trapezius, levator anguli scapulae, scalenus medius, and sterno-cleido-mastoid. 
 
 The Brachial or Axillary Plexus. A comprehensive knowledge of this 
 
 plexus, for dissecting-room purposes, must include the following points : 
 
 1. The formation by the union of the anterior primary divisions of the fifth, 
 sixth, seventh, and eighth cervical nerves, and the greater part of the first dorsal 
 or thoracic nerve. 
 
 2. The location of emergence of the above between the scalenus anticus and 
 scalenus medius muscles. 
 
 3. The communications which are with the fourth cervical ; with the second 
 and third thoracic nerves ; with the phrenic nerve ; with the inferior cervical 
 ganglion of the sympathetic. 
 
 4. The relations with the subclavian artery below ; with the clavicle and 
 subclavius muscle in front ; with the serratus magnus and subscapular muscles 
 behind. 
 
 5. The sheath formed by the axillary prolongation of the third layer of deep 
 cervical fascia, investing the plexus and axillary vessels, and finally forming the 
 suspensory or axillary fascia proper. 
 
 6. The formation of three brachial trunks : upper, middle, and lower. The 
 upper by the fusion of the fifth and sixth ; the middle by the seventh ; and the 
 lower trunk by the eighth cervical and the greater part of the anterior primary 
 division of the first dorsal nerve. 
 
 7. The splitting of the brachial trunks into anterior and posterior brachial 
 divisions. 
 
 8. The formation of the posterior cord by the union of the three posterior 
 brachial divisions. 
 
 9. The formation of the outer cord by the union of the anterior brachial 
 divisions of the upper and middle trunks. 
 
 10. The formation of the inner cord by the anterior brachial division of the 
 lower trunk. 
 
 1 1 . The branches of distribution to muscles ; to the skin covering these 
 muscles in general ; to the skin covering the insertions of these muscles in 
 particular ; to articulations where there is motion produced by muscles supplied 
 by the brachial plexus. 
 
 12. The inosculation between sensory nerves and motor nerves peripherally. 
 
 13. Branches given off above the clavicle; branches thrown off below the 
 clavicle, or from the plexus proper. 
 
7 8 PRACTICAL ANATOMY. 
 
 The branches you will find given off above the clavicle : 
 
 1. Muscular branches to the subclavius, scaleni, longus colli, rhomboidei, 
 as indicated in figure 42. 
 
 2. A communicating branch to the phrenic nerve. Follow the phrenic 
 nerve up, on the scalenus anticus muscle, and you will find a delicate nerve 
 coming through the muscle. 
 
 3. The posterior thoracic nerve, also called the long thoracic, the external 
 
 FACIAL NERVE 
 
 AURICULAR BR. OF 
 
 GREAT AURICULAR 
 
 IfiFRAMANDIB ULAR 
 
 SUPERFICIAL CERVICAL 
 BRANCHES OF SUPER- ( 
 FICIAL CERVICAL { 
 NERVE 
 
 SUPRASTERNAL 
 
 ) BRANCHES OF 
 V GREA T 
 ) AURICULAR 
 
 (IRE AT OCCIPITAL 
 
 I.K.1SER OCCIPITAL 
 
 HREAT AUSICCLAR 
 MASTOID BR. OR and 
 
 SMALL OCCIPITAL 
 SPINAL ACCESSOR F 
 
 TWIGS FROM THE 
 MASTOID BRAXCB 
 
 BR. TO LKVATOR 
 
 AffGULI SCAPULA 
 Sl'PRA- A CR OMIAL 
 
 S CPRA CLA VICL' LA R 
 
 BRANCHES TO 
 
 TRAPEZim 
 
 SL'PRAULA VICl'LAX 
 
 FIG. 43. SUPERFICIAL BRANCHES OF THE CERVICAL PLEXUS. (After Hirschfeld and Leveille.) 
 
 phrenic, and external respiratory nerve of Bell, supplies the serratus magnus 
 muscle. You will find this nerve in the axillary space. 
 
 4. The suprascapular nerve (Fig. 42) arises from the upper trunk. It passes 
 through the suprascapular foramen, in the superior costa of the scapula and 
 supplies the supra- and infraspinati muscles. 
 
 Branches from t/ic UnicJiial Plexus /'refer. Outer cord: External anterior 
 thoracic nerve to pectoralis major ; outer head of the median nerve fuses with 
 inner head from the inner cord of the plexus ; musculo-cutaneous nerve to 
 flexors of the forearm and coraco-brachialis. 
 
 Inner cord : Internal anterior thoracic to pectoralis minor ; inner head of the 
 
THE HEAD AND NECK. 79 
 
 median nerve fuses with the outer head from the outer cord ; internal cutaneous 
 nerve, to inner forearm ; lesser internal cutaneous, to inner arm ; ulnar nerve, 
 to forearm and hand. 
 
 Posterior cord : Three subscapular nerves to posterior wall of axilla ; 
 musculo-spiral to the muscles of the posterior part of arm and forearm ; circum- 
 flex to the deltoid and teres minor. 
 
 THE MOUTH. 
 
 The structures seen in the mouth of a patient are : 
 
 1. The tongue-tip, dorsum, and sides. 
 
 2. The dental arches and the teeth. 
 
 3. The vestibule the space outside the dental arches. 
 
 4. The frsenum linguae. 
 
 5. The uvula in mid-line of the soft palate. 
 
 6. Tonsil in the tonsillar recess. (Fig. 47.) 
 
 7. The palato-glossal fold of mucous membrane. (Fig. 47.) 
 
 8. The palato-pharyngeal fold of mucous membrane. (Fig. 47.) 
 
 9. The posterior pharyngeal wall. 
 
 10. The orifice of Stenson's duct, opposite second upper molar. 
 
 1 1. The general oral mucous membrane. 
 
 12. The soft palate and its subdivisions. 
 
 The fold of mucous membrane, the palato-glossal fold, is supported by a 
 muscle the palato-glossal muscle. Also a muscle, the palato-pharyngeal, is 
 under the palato-pharyngeal fold of mucous membrane. These two muscles 
 form the anterior and posterior boundaries of the tonsillar recess, in which is 
 found the tonsil. Having made yourself familiar with the physical appearances 
 of the above structures on the living, find on the cadaver the following : 
 
 1. The genio-hyoid muscle. (Fig. 47.) 
 
 2. The genio-hyo-glossus muscle. (Fig. 47.) 
 
 3. The stylo-hyoid muscle. (Fig. 35.) 
 
 4. The stylo-glossus muscle. 
 
 5. The stylo-pharyngeus muscle. 
 
 6. The Eustachtan orifices and pharyngeal tonsil. 
 
 7. The lingualis muscle. (Fig. 46.) 
 
 8. The tonsil in its recess ; between what two muscles ? 
 
 9. The palato-pharyngeal fold and muscle. 
 
 10. The palato-glossal fold and muscle. 
 
 1 1. The hypoglossal nerve (twelfth cranial). (Fig. 31.) 
 
 1 2. The gustatory nerve (lingual of fifth cranial nerve). 
 
 13. The glossal branch of glosso-pharyngeal nerve. (Fig. 34.) 
 
 14. The chorda tympani of the seventh cranial nerve. 
 
 15. The lingual artery and vein. (Figs. 31 and 47.) 
 
 16. The salivary apparatus and blood-supply. (Fig. 45.) 
 
 17. The mylo-hyoid muscle the floor of the mouth. (Fig. 35.) 
 
 1 8. The isthmus of the fauces. 
 
 19. The anterior pillar = palato-glossus muscle. (Fig. 47.) 
 
 20. The posterior pillar == palato-pharyngeus muscle. (Fig. 47.) 
 
 21. The azygos uvula,' muscle. 
 
 22. The levator palati muscle. 
 
 23. The circumflexus palati (tensor palati). 
 
 How to Dissect the Tongue. The dissection of the neck, you will recall by 
 
8o 
 
 PRACTICAL ANATOMY. 
 
 examining your work, has exposed the anterior belly of the digastric muscle, 
 the hyo-glossus muscle, the mylo-hyoid muscle, the branches of the external 
 carotid artery, the hypoglossal nerve, and, to some extent, the muscles and liga- 
 ments attached to the styloid process of the temporal bone. To dissect the 
 tongue and mouth you proceed as follows : Retract the chin, saw through the sym- 
 physis menti ; then, with a sharp knife, cut through the center of the tongue from 
 tip to hyoid bone. You will then see, separated by connective tissue areas, the 
 mylo-hyoid, the genio-hyoid, and the genio-hyo-glossus muscles as in figure 44. 
 24. The boundary between the mouth and the pharynx. Examine a patient 
 and you will see the soft palate hanging down between the mouth and pharynx. 
 
 Stylo-glOBSua 
 
 DORSUM OF TONGUE 
 
 Genio-hyo-glossus 
 Genio-hyoid 
 
 STYLOID PROCESS 
 Stylo-hyoid 
 
 POSTERIOR PORTION 
 OF TONGUE 
 
 Cut edge of mylo-hyoid 
 / 
 
 BODY OF HYOID BONE 
 
 11 
 
 
 /i 
 
 EPIGLOTTIS 
 
 V 
 
 (indicated by dotted Una) 
 
 \\ 
 
 GREATER CORNU OF HYOID BONE 
 
 Stylo-phary ngeun 
 
 CARTILAGO TRITICEA 
 
 Thyro-hyoid 
 membrane 
 
 THYROID CARTILAGE 
 
 Median portion of 
 crico-thyroid 
 membrane 
 
 CRICOID CARTILAGE 
 FIRST RING OF TRACHU 
 
 FIG. 44. SIDE VIEW OK THE TONGUE, WITH ITS Mt SCI.KS. 
 
 The passage between the two cavities, bounded by the tongue, anterior pillar of 
 fauces, and uvula is called the isthmus of the fauces. The student should early 
 become familiar with the soft palate, as its function is complex and of a very 
 interesting and practical nature. 
 
 Study the movements of the hyoid bone : 
 
 1. Elevated by the stylo-hyoid and digastric behind and the genio-hyoid 
 and mylo-hyoid in front. These muscles are clearly antagonistic. The former 
 are supplied by the seventh, the latter by the twelfth and fifth nerves. 
 
 2. Forward. The genio-hyoid, when not antagonized by the stylo-hyoid, 
 pulls the tongue forward. 
 
THE HEAD AND NECK. 
 
 81 
 
 3. Backward. The stylo-hyoid and digastric, when not antagonized by the 
 mylo-hyoid and genio-hyoid, pull the hyoid bone backward. 
 
 4. Downward. The depressor muscles of the hyoid bone, when not antag- 
 onized, pull the hyoid bone down, and with it the tongue. The depressors of the 
 hyoid bone are the sterno-hyoid, omo-hyoid, sterno-thyroid, and thyro-hyoid 
 muscles. Their nerve-supply is from the ansa hypoglossal loop. 
 
 Study the simple movements of the tongue and the muscles that produce 
 them. 
 
 1 . Protrusion beyond the teeth = deep part of genio-hyo-glossus. 
 
 2. Retraction = superficial part of genio-hyo-glossus. 
 
 3. Convex dorsurn = hyo-glossi. 
 
 4. Concave dorsum = inferior part of lingualis and stylo-glossus. 
 
 5. Shorten tongue = the lingualis. 
 
 SOCIA PAROTIDIS 
 
 DUCT OF SOCIA 
 PAROTIDIS 
 
 DUCT OF PAROTID 
 
 Bristle inserted 
 into duct 
 
 Fraenum linguae 
 DUCT OF RIVINI 
 
 SUBLINGUAL GLAND 
 
 DUCT OF SUBMAXILLARY 
 
 GLAND 
 Mylo-hyoid muscle 
 
 Anterior belly of 
 digastric muscle 
 
 PAROTID GLAND 
 
 Masseter muscle 
 
 Sterno-mastoid 
 muscle 
 
 Posterior belly of 
 digastric muscle 
 
 SUBMAXILLARY GLAND, 
 DRAWN BACKWARDS 
 
 Loop of fascia 
 
 DESP PORTION OF SUBMAXILLARY GLAND 
 FIG. 45. SIDE OF THE FACE AND MOUTH CAVITY, SHOWING THE THREE SALIVARY GLANDS. 
 
 There may be a great number of compound movements. Thus, the tongue 
 may be concave-dorsum, in protrusion or retraction ; convex-dorsum, the same. 
 In any of the foregoing positions the whole organ may be turned to either side, 
 or the base may be elevated. 
 
 Divide the connective tissue between the genio-hyoid and genio-hyo-glossus. 
 (Fig. 44.) The genio-hyoid arises from the inferior genial .tubercle of the 
 mandible. (Fig. 9.) It is inserted into the body of the hyoid bone. 
 
 The genio-hyo-glossus arises from the superior genial tubercle. (Fig. 9.) 
 It has a superficial insertion into the anterior part of the tongue ; a deep inser- 
 tion into the body of the hyoid ; above the preceding, of course. This muscle 
 produces the rapid protrusion and retraction of the tongue. 
 
 The mylo-hyoid muscle forms the floor of the mouth. Divide the con- 
 nective tissue between it and the genio-hyoid. (Fig. 44.) This muscle arises 
 from the oblique line of the mandible the mylo-hyoid ridge. (Fig. 9.) A 
 
82 PRACTICAL ANATOMY. 
 
 small part of the posterior part of the muscle is inserted into the body of the 
 hyoid bone ; the greater part of the muscle is inserted into the median line with 
 its fellow of the opposite side. (Fig. 35.) 
 
 Relations of the Mylo-hyoid Muscle. Cut through the mucous mem- 
 brane, between the border of the tongue and the alveolar process of the 
 mandible, and you will see the superior surface of the mylo-hyoid muscle. On 
 this surface find : 
 
 1. The gustatory nerve, the sensory (a branch of the fifth cranial), anasto- 
 mosing, in the substance of the tongue, with the hypoglossal, the motor nerve 
 of the tongue. (Fig. 45.) 
 
 2. Find the sublingual salivary gland, communicating, around the posterior 
 margin of the mylo-hyoid, with the submaxillary salivary gland. (Fig. 45.) 
 
 3. Find the anterior belly of the digastric muscle (Fig. 35) under resting 
 upon the under surface of the mylo-hyoid muscle. Note a branch of the mylo- 
 hyoid nerve to this muscle. This muscle arises from the digastric fossa of 
 mandible. (Fig. 9.) 
 
 4. The hyo-glossus muscle arises from the body and both horns of the 
 
 Transverse muscular fibres 
 
 PAPILLA 
 
 Superior lingual 
 muscle 
 
 Septum 
 
 Submueous 
 
 ^^ tissue 
 
 Inferior lingual 
 muscle, mixed 
 with extrinsic 
 fibre* 
 
 Vertical muscular fibres 
 
 FIG. 46. TRANSVKRSB SECTION THROUGH THE LEFT HALF OF THE TONGUE. 
 
 (Magnified.) 
 (From a preparation by Mr. J. Pollard, Middlesex Hospital Museum.) 
 
 hyoid bone. (Fig. 48.) It is inserted into the tongue. On its outer surface find 
 the hypoglossal nerve. (Fig. 34.) On its inner surface see the lingual artery 
 (Fig. 47) dividing in (i) the dorsalis linguae; (2) the ranine artery. (Fig. 36.) 
 
 The Stylo-glossus and Stylo-hyoid. Trace the former to the side of the 
 tongue, the latter to the side of the body of the hyoid bone. Their origins will 
 be seen at a later stage of the dissection. (Fig. 48.) 
 
 The musculi linguales, or proper intrinsic muscles of the tongue, may be 
 studied in the longitudinal section (Fig. 46) to a limited extent on your work. 
 
 Deep Dissection of the Pterygo-styloid Region. In this region you will find 
 the following : 
 
 1 . The stylo-maxillary or stylo-mandibular ligament, a derivative of the 
 first layer of cervical fascia, extending from the styloid process of the temporal 
 bone to the ramus and angle of the mandible. It is between the masseter muscle 
 and the internal pterygoid muscle. 
 
 2. The temporo-mandibular articulation, with its interarticular fibro-car- 
 tilage dividing the glenoid cavity into an anterior and a posterior synovial cavity. 
 
THE HEAD AND NECK. 83 
 
 3. The external pterygoid muscle, with one insertion into the depression 
 in front of the condyle, and another into the interarticular fibro-cartilage. 
 
 4. The internal pterygoid muscle, inserted into the inner surface of the 
 ramus. See this muscle coming down from the pterygoid fossa. 
 
 Descending palatine artery 
 Palato-pharyngeus 
 
 TONSIL 
 
 Ascending palatine branch 
 
 of facial 
 Tonsillar branch of dorsalis 
 
 lingual 
 
 Tonsillar branch of facial 
 Stylo-gloBsus 
 
 Dorsalis linguae artery 
 
 Middle constrictor 
 HYPOGLOSSAL NERVE 
 
 Facial artery 
 
 Posterior belly of digastric 
 and stylo-hyoid 
 Supra-hyoid branch 
 
 SUP. LARYNOEALN. 
 
 Infra-hyoid branch 
 Internal carotid artery 
 
 Falato-glossus 
 
 Ranine artery 
 
 Common carotid artery 
 
 FIG. 47. SCHEME OF THE RIGHT LINGUAL ARTERY. (Walsham.) 
 
 a inferior / I 
 
 Lingual! 
 
 Qenio-hyo-glOBBUB 
 
 Genio-hyoid 
 
 Anterior belly of 
 
 digastric 
 
 Hyo-glosBus 
 
 Mylo-hyoid 
 
 FIG. 48. SIDE VIEW OF THE MUSCLES OF THE TONGUE. 
 
 5. The inferior dental nerve and artery, between the neck of the mandible 
 and the internal lateral ligament of the joint. This ligament you will see 
 extending from the spine of the sphenoid to the lingula of the mandible ; under 
 it are the above structures, the inferior dental nerve and vessels. 
 
 6. The internal maxillary artery (Fig. 51), between the neck of the jaw 
 
PRACTICAL ANATOMY. 
 
 External pterygoid 
 
 Internal pterygoid 
 
 FIG. 49. THE PTERYGOID MUSCI.KS. 
 
 LONG BUCCAL 
 NERVE 
 
 SUB- 
 
 ttANDIBULAR 
 GANGLION 
 
 MENTAL 
 
 BRANCH 
 
 ANTERIOR TEM- 
 PORAL NEB VE 
 
 A URICULO-TEM- 
 PORAL NERVE 
 
 POSTERIOR TEM- 
 PORAL NERVE 
 
 NERVE TO MAS- 
 SETER 
 
 CHORDA TYM- 
 PANI 
 
 MYLO-HYOID 
 
 NERVE 
 LINGUAL 
 NERVE 
 
 DENTAL XERVB 
 
 l,;. 50. DlSTRlHHl'ION OK TIIK MAN 1)1 IHII.AR DIVISION OK TIIK TRIGKMINAI. \KRVK. (Henle.) 
 
THE HEAD AND NECK. 85 
 
 and the spheno-mandibular ligament. You will see it on the outer surface of the 
 external pterygoid muscle. 
 
 7. The styloid process, muscles and ligaments attached. 
 
 1. The stylo-hyoid muscle. 
 
 2. The stylo-pharyngeus muscle. 
 
 3. The stylo-glossus muscle. 
 
 4. The stylo-mandibular ligament. 
 
 5. The stylo-hyoid ligament. 
 
 Trace each from its styloid origin to its specific insertion. 
 
 Dissection. The above deep structures will be readily found on dividing the 
 temporo-mandibular ligament. As you do this, notice the interarticular fibro- 
 cartilage. Between the neck of the jaw and the internal lateral ligament find 
 the first stage of the internal maxillary artery. 
 
 The external pterygoid muscle (Fig. 49) originates by two heads : (i) From 
 the outer surface of the external pterygoid plate. (2) From the pterygoid ridge 
 on the outer surface of the greater wing of the sphenoid bone. It has two 
 insertions: (i) Into the interarticular fibro-cartilage of the temporo-mandibular 
 articulation ; (2) into a depression in front of the condyle of the jaw. 
 
 The inferior dental nerve (Fig. 51) is a branch of the inferior maxillary 
 division of the fifth cranial. It passes between the ramus of the jaw and the 
 spheno-mandibular ligament, in company with an artery of the same name, 
 and enters the inferior dental canal. (Fig. 50.) It throws off in its course 
 dental branches to the teeth ; a large cutaneous branch, the mental, to the 
 skin of the chin. The mental branch comes to the surface through the mental 
 foramen. (Fig. 8.) The inferior dental artery takes the same course and has a 
 similar distribution. (Fig. 51.) 
 
 The mylo-hyoid nerve is given off from the inferior dental as the latter is 
 entering the mandibular canal in the mandible. It lies in a groove on the inner 
 surface of the lower jaw, and is covered by the periosteum. It supplies the 
 mylo-hyoid muscle and the anterior belly of the digastric muscle with motion. 
 
 1 . What is the buccal orifice ? 
 
 A transverse slit, bounded by the lips, and terminating laterally in the 
 angles ; by it the mouth communicates with the external world. 
 
 2. What is the isthmus of the fauces? 
 
 It is the buccal opening of the pharynx. It is bounded by the tongue below, 
 soft palate above, and pillars of the fauces laterally, and by it the mouth com- 
 municates with the pharynx. 
 
 3 . Hcnv is the soft palate made up, and to what is it attached ? 
 
 Its special parts are : (i) The uvula ; (2) the anterior and posterior pillars of 
 the fauces ; (3) the tonsillar recess between the pillars. This should be studied 
 on the living subject. 
 
 4. What is the vestibule ? 
 
 The part of the oral cavity bounded by the cheeks and lips externally and 
 the dental arches internally. 
 
 5. What muscle lies under the anterior pillar of the fauces and helps form the 
 
 same . 
 
 The palato-glossus muscle, very readily seen. 
 6. What is the action of this muscle f 
 
 In the act of swallowing it draws the tongue upward and the anterior pillars 
 downward, hood-like, over the back of the tongue; this closes the buccal orifice 
 
86 
 
 PRACTICAL ANATOMY. 
 
 of the pharynx and prevents regurgitation of ingesta into the mouth, thereby 
 enabling the constrictors of the pharynx to grasp the bolus to be swallowed. 
 
 7. What muscle lies under tJie fold of mucous membrane of the posterior pillar 
 of the fauces ? 
 
 The palato-pharyngeus. This muscle is inserted into the superior cornu of 
 the thyroid cartilage, and also into the fibrous part of the pharynx. The action 
 of this muscle is to assist deglutition by elevating the pharynx by stretching 
 the pharynx over the bolus, as it were. 
 
 The act of swallowing may be compared to a most delicately acting cylinder 
 and piston : The tongue is the piston ; the isthmus of the fauces, the cylinder 
 in which the piston plays ; the junction between the pharynx and the oesophagus 
 
 Infraorbital artery and nerve 
 
 Orbital branch. 
 
 Nasal branch 
 Anterior 
 dental branch I 
 
 Labial branch \ 
 Posterior dental 
 branch 
 
 Incisive branch 
 Mental branch 
 
 Submental branch 
 
 Spheno-palatine branch 
 
 Posterior, or descending palatine branch 
 Naso-palatine branch 
 
 Vidian branch 
 
 A nterior deep temporal artery 
 External pterygoid branch 
 
 I Posterior deep temporal artery 
 
 Small meningeal 
 artery 
 
 Middle meningeal 
 artery 
 
 Temporal artery 
 Tympanic branch 
 
 Deep auricular 
 
 branch 
 
 AriiH'ULO-TEM- 
 PORAL XEKVK 
 Masseteric branch 
 
 External carotid 
 artery 
 
 Internal lateral or 
 spheno-mandibu- 
 lar ligament 
 
 Afandibular or 
 inferior dental 
 artery and nerve 
 
 Succal branch with Internal pterygoid branch 
 portion of buccal nerve 
 
 Mylo-hyoidean branch 
 
 FIG. 51. SCHEME OF INTERNAL MAXILLARY AKTI.KY. 
 
 is the escape. The digastric and stylo-hyoid muscles elevate the tongue ; at the 
 same time the palato-glossus draws the tongue backward, piston-like, through 
 the isthmus, thereby preventing regurgitation and at the same time pressing 
 onward the food. At this juncture the palato-pharyngeus muscle depresses the 
 soft palate, thereby aiding the preceding muscle, and at the same time pulls up 
 the pharynx, just as one pulls a stocking on. 
 
 S. \VIiat would be tlie result were the poloto-pkaryngfUS muscle paralyzed, and 
 do such circumstances arise in the practice of medicine / 
 
 The result would be loss of the delicate part of the act of swallowing. 
 Solids would find their way to the stomach, but fluids, more difficult to grasp, 
 l>y the constriction of the pharynx would regurgitate through the nose, under 
 
THE HEAD AND NECK. 87 
 
 these conditions, this being the line of least resistance. Such cases of regurgita- 
 tion are met as sequels of diphtheria. 
 
 9. Locate the tonsil. 
 
 It is between the anterior and posterior pillars of the fauces ; it corresponds 
 in position to the angle of the jaw ; the superior constrictor of the pharynx is 
 external to it, while the internal carotid artery is fully one inch from it. It is 
 the ascending pharyngeal artery, between the tonsil and the superior constrictor, 
 and not the internal carotid artery that is in danger of being wounded in tonsil- 
 lotomy. 
 
 i o. Explain the mylo-hyoid nerve. 
 
 It is a branch of the inferior dental, being given off while this nerve is 
 between the ramus and spheno-mandibular ligament. It pierces the spheno- 
 mandibular ligament, passes along the mylo-hyoid groove, and supplies the 
 anterior belly of the digastric and the mylo-hyoid muscle. This nerve is a part 
 of the motor root of the fifth, ensconsed in the sheath of the (sensory) inferior 
 dental part of the fifth, given off from the Gasserian ganglion. (Fig. 53.) 
 
 1 1 . Name and explain fully the structures attacked to the styloid process of the 
 temporal bone. (Fig. 44.) 
 
 There are three muscles and two ligaments: (i) The stylo-hyoid muscle. 
 This muscle arises from the back and outer surface of the styloid process, near the 
 base. It lies above the posterior belly of the digastric muscle. Near its inser- 
 tion into the body of the hyoid, at the junction of the body and greater horn, 
 it bridges the intermediary tendon of the digastric. In its action it is synergistic 
 with the posterior belly of the digastric, the two being supplied with motion by 
 the seventh nerve. (2) The stylo-glossus muscle arises from the front and tip of 
 the styloid process, also from the upper part of the stylo-mandibular ligament. 
 It is inserted into the side and under surface of the tongue. Its action is to draw 
 the sides of the tongue up to make the dorsum of this organ concave from side 
 to side. (3) The stylo-pharyngeus arises from the base of the styloid process, 
 opposite the stylo-hyoid. It is inserted, with the palato-pharyngeus, into the thy- 
 roid cartilage, and also into and with the constrictors of the pharynx. (4) The 
 stylo-maxillary or stylo-mandibular ligament will be seen in your dissection as a 
 process of deep cervical fascia, a derivative of the third layer, between the 
 masseter and internal pterygoid muscles. It separates the parotid from the 
 submaxillary gland. It gives origin to one head of the stylo-glossus muscle. 
 (5) The stylo-hyoid ligament extends, as a small elastic fibrous cord, from the 
 tip of the styloid process of the temporal bone to the lesser cornu of the hyoid 
 bone. It frequently becomes ossified. Occasionally it is of enormous size. 
 
 12. Describe tJie external pterygoid muscle. (Fig. 49.) 
 
 This muscle has two origins and two insertions. The upper head arises from 
 the under surface of the greater wing of the sphenoid bone, limited internally by 
 the foramen ovale, transmitting the third division of the fifth nerve, and the fora- 
 men spinosum, transmitting the great meningeal artery ; externally, the origin of 
 this head is limited by the pterygoid ridge. The lower head arises from the 
 greater part of the outer surface of the external pterygoid plate. The upper 
 head is inserted into the interarticular fibro-cartilage ; the lower into the front of 
 the condyle. The action of the muscle is to draw the condyle well forward, 
 and with it also the interarticular cartilage. It also moves the jaw to the oppo- 
 site side, and assists to some extent in opening the mouth. 
 
 13. Describe tlic internal pterygoid muscle. (Fig. 49.) 
 
 It arises from the inner surface of the external pterygoid plate, and from the 
 tuberosity of the palate bone. It is inserted into the inner surface of the ramus 
 of the mandible, limited above by the mylo-hyoid ridge and inferior dental foramen. 
 The action is to close the mouth and draw the jaw forward and to the mid-line. 
 
88 
 
 PRACTICAL ANATOMY. 
 
 The nerves to the pterygoid muscles are from the third division of the fifth 
 nerve. (Fig. 53.) The blood-supply comes from the internal maxillary artery, 
 second stage. (Fig. 51.) 
 
 Describe the internal maxillary artery. (Fig. 51.) 
 
 First Stage. Behind the neck of the mandible. In this stage it gives off: 
 
 1. The inferior dental artery to the inferior teeth. 
 
 2. The great meningeal artery to the dura and calvarium. 
 
 3. The small meningeal artery to the dura mater. 
 
 4. The deep auricular branch to external canal. 
 
 5. Tympanic, to the membrana tympani. 
 
 Temporal 
 
 Buccinator 
 
 FIG. 52. THE TEMPORAL MUSCLE. 
 
 The second stage of the artery gives off branches to muscles of mastication 
 
 1. Deep temporal branches to temporal muscles. 
 
 2. Buccal branch to the buccinator muscle. 
 
 3. Internal pterygoid branch to internal pterygoid muscle. 
 
 4. External pterygoid branch to external pterygoid muscle. 
 
 5. Masseteric branch, to the masseter. 
 
 The second or pterygoid stage lies on the outer surface of the external ptery- 
 goid muscle, under cover of the temporal muscle and the ramus of the mandible. 
 
 The third stage of the artery gives off these branches : 
 
 i. The posterior superior dental artery. This is confusing, and requires an 
 explanation. The dental branches supply the teeth. They enter the posterior 
 superior dental canals, through foramina on the posterior surface of the body of 
 the superior maxilla. The alveolar branches supply the gums. Some branches 
 supply the mucous membrane of the antrum ; these might be called antral 
 branches. 
 
THE HEAD AND NECK. 
 
 89 
 
 2. The infraorbital artery enters the infraorbital canal in the floor of the orbit. 
 It appears on the face as the infraorbital. It gives branches to the anterior teeth. 
 These latter pass through the anterior superior dental canals in the anterior wall 
 of the antrum. 
 
 3. Descending palatine passes through the posterior palatine canal, along 
 the roof of the mouth, to the foramen of Stenson, where it anastomoses with the 
 naso-palatine artery. It accompanies the anterior branch of Meckel's ganglion. 
 
 4. The spheno-palatine passes through the spheno-palatine foramen into the 
 cavity of the nose. It divides into the naso-palatine branch to the septum, 
 
 FIG. 53. SCHEME OF THE DISTRIBUTION OF THE FIFTH CRANIAL OR TRK;F.MINAL NERVE. 
 Notice especially: (l) The recurrent branch from the Gasserian ganglion to the dura of the middle fossa 
 and tentorium. (2) Filaments from the carotid plexus. (3) The motor root of the fifth nerve behind 
 the ganglion, but independent thereof. (4) The formation of the otic, submaxillary, Meckel's, and 
 the ciliary ganglion. 
 
 which anastomoses with the descending palatine artery, and some external 
 branches to the lateral walls of the nose. 
 
 5. The Vidian nerve passes through the Vidian canal with the Yidian nerve. 
 It is distributed to the pharynx and Eustachian tube. 
 
 6. The pterygo-palatine passes through the pterygo-palatine canal. It is 
 distributed to the upper part of the pharynx and Eustachian tube. 
 
 Describe tJie inferior maxillary division of t/te fifth cranial nerve. 
 It passes through the foramen ovale with the small meningeal artery. It 
 gives off the following branches : 
 
 i. Muscular branches to all the muscles of mastication. These accompany 
 7 
 
9 
 
 PRACTICAL ANATOMY. 
 
 muscular branches of the internal maxillary artery and take the name of the 
 muscles. 
 
 2. The auriculo-temporal nerve. (Fig. 53.) The middle meningeal artery 
 passes between the two roots of this nerve. This nerve gives an articular 
 branch to the temporo-mandibular articulation. It does this in accordance with 
 Hilton's law. It gives branches to the external auditory meatus and the 
 membrana tympani, and is often responsible for ear-ache in children. It sends 
 branches to the scalp, with the temporal arteries, and may be the terminus of 
 visceral reflexes in the scalp. 
 
 3. The inferior dental nerve to (i) the teeth of the mandible ; (2) to the skin 
 of the chin (mental nerve) ; (3) to the anterior belly of the digastric ; and (4) to 
 the mylo-hyoid muscle, through the mylo-hyoid nerve. 
 
 4. The gustatory or lingual nerve, the great sensory nerve to the tongue. 
 It anastomoses in the tongue with the hypoglossal and the glossal branch of the 
 glosso-pharyngeal nerve. Special notice must be given this nerve, on account 
 
 STYLOID PROCESS 
 
 (i LOSSO-PHA R YN- 
 GEAL NERVE 
 
 HYPOOLOS8AL 
 
 .v /;/. i '!: 
 
 Occipital artery 
 
 HUB MAXILLARY 
 GANGLION 
 
 DUCT OF SUBMAXILLARY GLAND 
 
 Middle constrictor 
 muscle 
 
 l.ini/iKil iir/i'rt/ 
 
 /-:.sr/.;.v/>/-;.y,s .\o.\j 
 NERVB 
 
 Fir.. 54. MUSCLES, VKSSKLS, AND NERVKS OK THK TON<;I ; K. 
 
 of (i) the chorda tympani nerve; (2) the submaxillary ganglion ; (3) the ot 
 ganglion. 
 
 The chorda tympani nerve (Fig. 54) is a branch of the seventh cranial 
 nerve. It passes through the tympanum. It leaves this cavity by the canal 
 of Huguier in the petrous portion of the temporal bone. It passes between the 
 two pterygoid muscles. It meets the lingual nerve, and accompanies this to 
 the submaxillary gland. This nerve gives branches to the sublingual gland, the 
 lingualis muscle, and the submaxillary ganglion. 
 
 The Submaxillary Ganglion. (Fig. 54.) 
 
 (rii'C location of the subma.villary ganglion. 
 
 It is on the outer surface of the hyo-glossus muscle, attached to the gustatory 
 or lingual nerve. The ganglion is about the si/e of a pin's head. 
 
 Name the roots of the ganglion nn<1 give their source. 
 
 1 . Scnsorv root is from the gustatory nerve, a branch of the fifth nervr. 
 
 2. Motor root is from the chorda tympani, a branch of the seventh nerve. 
 
 3. Svmfwtltetic root is from the nervi molles the facial sympathetics. 
 
THE HEAD AND NECK. 
 
 9 1 
 
 Its branches are distributed to the mucous membrane of the floor of the 
 mouth and to the submaxillary gland and its duct. 
 
 The otic ganglion (Fig. 53) is on the inferior maxillary division of the fifth 
 nerve. Its roots are : 
 
 1. Motor, from the inferior maxillary division of the fifth nerve. 
 
 2. Sensory, from the auriculo-temporal branch of the fifth nerve. 
 
 3. Sympathetic > from a plexus on the middle meningeal artery. 
 Give tJie location and relations of the otic ganglion. 
 
 (i) External to it is the inferior maxillary nerve ; (2) Internal to it is the circum- 
 flexus (tensor) palati muscle ; (3) posterior to it is the middle meningeal artery. 
 
 Aside from the three root communications previously given, has the otic 
 ganglion any other communications ? 
 
 Yes ; it communicates with the seventh or facial nerve and with the glosso- 
 pharyngeal by the lesser petrosal nerve. 
 
 ANTERIOR DENTAL MAXILLARY NERVE ORBITAL BRANCH 
 
 MA X1LLA R Y NER I 'E 
 
 MECKEUS GANGLION 
 
 POSTERIOR DENTAL 
 
 LOOP FORMED BY MIDDLE AND ANTERIOR DENTAL NERVES 
 FIG. 55. THK MAXILLARY NERVE SEEN FROM WITHOUT. (Beaunis. ) 
 
 To what muscles are the branches of the otic ganglion distributed ? 
 To the tensor palati and tensor tympani. 
 
 Describe the superior maxillary division of the fifth cranial nerve. (Fig. 55.) 
 This nerve, a branch of the Gasserian ganglion, leaves the cranium by the 
 foramen rotundum in the greater wing of the sphenoid bone. The nerve crosses 
 the spheno-maxillary fossa, enters the orbit by the spheno-maxillary fissure, 
 traverses the infraorbital canal in the floor of the orbit, appears on the face at 
 the infraorbital foramen, and here communicates with the infraorbital branch of 
 the seventh nerve to form the infraorbital plexus. 
 Its branches are both numerous and important : 
 i. The nasal, labial, and palpebral on the face. (Fig. 53.) 
 Anterior superior dentals to incisor teeth. (Fig. 53.) 
 Posterior superior dentals to molar teeth. (Fig. 53.) 
 
 4. Spheno-palatine branches to Meckel's ganglion. (Fig. 53.) 
 
 5. Temporo-malar are cutaneous to the cheek and temple. 
 A recurrent meningeal branch to the dura. (Fig. 53.) 
 
 2. 
 
 3- 
 
 6. 
 
92 PRACTICAL ANATOMY. 
 
 Two CASES OF REFLEX PAIN. 
 
 A Patient has Pain in tJic Auditory Canal On examination you find no 
 local objective symptoms. Where may the real seat of the trouble be located ? 
 The auditory canal is supplied by the auriculo-temporal branch of the fifth 
 cranial nerve. The irritation may be sought for anywhere in the distribution of 
 this nerve, but, logically, those parts of the fifth nerve which experience has 
 proved are most liable to disease and injury should be interrogated first. We 
 may venture the assertion that the teeth, nose, eye, tongue, and antruin of High- 
 more represent about the order, in point of frequency. Here, then, is the 
 specialist invoked, since a carious tooth, an irritated gum, a septal spur, eye 
 strain, a lingual ulcer, or pus in the antrum of Highmore may be the immediate 
 exciting cause of the pain in the auditory canal. Conversely, a patient may have 
 a violent toothache, and examination may reveal neither exposed pulp nor irri- 
 tated gum. Conservative dentistry in this case would refer a patient to other 
 specialists, whose field of usefulness lies in the distribution of the fifth pair of 
 cranial nerves, primarily or secondarily, since reflex pain may be primary and 
 secondary. 
 
 What is meant by primary and secondary reflex pain f 
 
 The expression is a coinage, explained as follows : Where a carious tooth 
 manifests pain in the ear, eye, nose, anywhere in organs supplied by the same 
 nerve direct, this is called primary ; where, however, a carious tooth manifests 
 pain in distant regions, not supplied by the fifth nerve, but connected therewith 
 by communicating branches, this is called secondary. Let the following cases 
 illustrate the point and apologize for the coinage : 
 
 1. A patient consulted a prominent dentist in this city for intractable pain in 
 a molar tooth. Examination revealed no objective symptoms of disease. The 
 patient was advised to consult other specialists in the primary radius of the fifth 
 pair of nerves viz., the eye, nose, ear, or throat man. The patient disregarded 
 the specific character of the advice, and consulted a specialist in the secondary 
 radius of the fifth nerve, the gynaecologist, who removed an ovarian tumor. The 
 pain in the molar did not return. 
 
 2. Hilton reports a case from Romberg of cough and vomiting which ceased 
 only after a pruritus of the external auditory meatus was cured. The nerves 
 concerned in this case were the vagus and the trigeminus. 
 
 The general practitioner of medicine who facetiously disclaims confidence in 
 reports of " toothache in the ear, and earache in an ovary," as he is wont to call 
 such cases, is placing himself on record with those who a few years ago hooted 
 at asepsis. Pain is a projectile, and specialists in medicine to-day are doing more 
 than any one else to harmonize physiological speculations and anatomical nerve- 
 distributions and nerve-communications, by furnishing clinical evidence of that line 
 of least resistance which pain, as a projectile, must follow. The student of prac- 
 tical anatomy is urged to give special attention to those parts of nerve-trunks 
 recorded in the text-books as communicating branches, for upon these depends 
 the rationale of reflexes, on which so much is said and written. 
 
 The Glosso-pharyngeal Nerve (Fig. 54). You will find this nerve between 
 the jugular vein and internal carotid artery. It lies above the superior laryngeal 
 nerve, on the stylo-pharyngeus muscle and superior constrictor of the pharynx. 
 It is distributed to the back of the tongue and to the pharynx. This nerve is 
 deeply located. It can not be mistaken. It is the ninth cranial nerve. It 
 leaves the base of the cranium by the jugular foramen with the tenth and eleventh 
 nerves and the jugular vein. 
 
THE HEAD AND NECK. 93 
 
 THE MUSCLES OF MASTICATION. 
 
 TJic muscles of mastication are the temporal, buccinator, the internal and 
 external pterygoids, and the masseter. (Figs. 56 and 57.) These are the power- 
 ful muscles that act on the mandible, by whose action the food is cut by the 
 incisors, torn by the canines, and triturated by the molars. It would seem that 
 the muscles that depress the jaw belong to the same category; hence we will 
 consider them incidentally here, in detail in another section. 
 
 The temporal muscle (Fig. 52) arises from the complete temporal ridge, 
 from the temporal fossa, and from the under surface of the temporal fascia. It 
 is inserted into the coronoid process of the mandible, as far forward as the last 
 molar tooth. The muscle is triangular ; hence, according to rule, it will be found 
 taking its nerve-supply near the apex. It derives its nerve-supply from the 
 third division of the trigeminus. (Fig. 53.) In your dissection you find this 
 muscle related superficially to the arcus zygomaticus, the temporal fascia, the 
 temporal branches of the seventh nerve, the superficial temporal arteries and 
 veins, and the auriculo-temporal branch of the fifth nerve. (Figs. 15-17.) 
 Deeply the muscle is related to the temporal fossa and the external pterygoid 
 muscle. 
 
 The buccinator muscle (Fig. 62) arises from the alveolar processes above 
 the upper and below the lower molar teeth of the upper and lower jaws respec- 
 tively ; and from the pterygo-maxillary ligament. It is inserted into the outer 
 part of the orbicularis oris. Its function is (i) to draw the corners of the mouth 
 outward and backward against the teeth ; (2) to antagonize the tongue by per- 
 mitting no food to be pushed by this organ beyond the dental arches, into the 
 vestibule during mastication. 
 
 The internal pterygoid muscle (Fig. '57) arises from the inner surface of the 
 external pterygoid plate, from the tuberosity of the palate bone. It is inserted 
 into the inner surface of the ramus of the mandible, as high as the inferior dental 
 foramen and mylo-hyoid groove. The muscle is quadrangular ; hence, according 
 to rule, it takes its nerve-supply in the centre. The action of the muscle is to 
 close the mouth and draw the jaw forward and to the mid-line. 
 
 Name the agents thai depress the lower jatv. 
 
 The digastric muscle, the platysma myoides, and gravity. 
 
 / ? 'liicJi muscles act on the mandible, to protrude the lower ja^iv ? 
 
 The external pterygoid muscle and the superficial part of the masseter 
 muscle. 
 
 Hoiv is the mandible returned to its original position in the glcnoid ? 
 
 It is drawn back by the posterior fibres of the temporal muscle, and by the 
 deep fibres of the masseter muscle. 
 
 \ \ liat are the ifiuscles of trituration ? 
 
 The external pterygoids. They act alternately, drawing the mandible 
 forward and to the opposite side : this movement produces trituration. 
 
 WJiat is the function of the temporal, masseter, and internal pterygoid muscles ? 
 
 They raise the mandible against the upper jaw with great force. 
 
 Has the temporal muscle an independent, specific action ? 
 
 Yes, its specific action is to accentuate incision. The quick snapping move- 
 ment of the jaw is done by this muscle. 
 
 What is meant by superficial and deep part of the masseter muscle / 
 
 Your knowledge of the action of the masseter muscle on the mandible is 
 imperfect without an understanding of these two parts : In reality each masseter 
 is two muscles. Each part of the masseter muscle has a separate origin, separate 
 function, separate insertion. One the superficial is strong, tendinous, and 
 
94 
 
 PRACTICAL ANATOMY. 
 
 active in assisting the external pterygoid muscle, in drawing the lower molars 
 across the upper molars, in trituration of food ; the other the deep portion 
 is weak, broad, muscular, and almost passive in assisting the posterior segment 
 of the temporal muscle in bringing the mandible back to its position, preparatory 
 to another movement of trituration. 
 
 The specific origins and insertions of these separate parts of the masseter 
 muscle make possible the separate physiological functions, as above indicated. 
 Study them separately, as follows : 
 
 The superficial part of the masseter (Fig. 56) muscle arises: (i) From 
 
 Corrugatpr 
 supercilii 
 
 Fyramidalis 
 
 Levator labii 
 
 Buperioris 
 
 alaequc nasi 
 
 Levator labii 
 
 Buperioris 
 
 Compressor 
 
 uarium 
 Levator anguli 
 
 oria 
 
 Naso-labialis 
 Depressor alae 
 
 nasi 
 Orbicularis oris 
 
 Buccinator 
 
 Depressor 
 
 anguli oris 
 
 Depressor labii 
 
 inferioris 
 Levator menti 
 Mylo-hyoid 
 
 Anterior belly of 
 digastric 
 
 Temporal 
 
 Zygomaticus 
 major 
 
 Posterior belly 
 of digastric 
 
 Splenius capitis 
 
 Stylo-hyoid 
 
 Sterno-mastoid 
 
 Levator anguli 
 scapulae 
 
 Scalenus anticus 
 
 IMC. 56 '1'iiK. DKH-F.K LAYKK 01 nil-. Mr-ri.Ks 01 TMK FACE AND NKCK. 
 
 the malar process of the superior maxilla by a strong tendon ; (2) from the 
 anterior two-thirds of the lower border of the /.ygomatic arch. From this strong 
 origin the fibres pass backward and downward to their insertion into the lower 
 half and angle of the outer surface of the ramus. (Fig. 58.) The action is to 
 draw the mandible forward. The synergist of this segment of the masseter is 
 the external pterygoid. 
 
 The deep portion of the masseter (Fig. 56) muscle arises : (i) From the 
 inner surface of the /.ysj,omatic arch ; (2) from the lower border of the posterior 
 
THE HEAD AND NECK. 
 
 95 
 
 third of the zygoma. This portion is inserted into the upper half of the outer 
 surface of the ramus. (Fig. 58.) Its action is to assist the posterior segment 
 of the temporal muscle in drawing the mandible backward. 
 
 The external pterygoid muscle (Fig. 57) originates when- and is hcnv 
 inserted ? 
 
 The function of this muscle is second to none, hence its bony and cartil- 
 aginous attachments merit special notice. Here, as in the preceding case, there 
 are in reality two muscles. They are, however, described as upper and lower 
 heads of one muscle. 
 
 The upper head arises from the pterygoid ridge on the outer and under surface 
 of the greater ala of the sphenoid bone. Its specific insertion is, according to my 
 experience, confined to the interarticular fibre-cartilage of the temporo-mandibular 
 articulation. The function would seem to be to regulate the movements of this 
 
 External ptefygoid 
 
 Internal pterygoid 
 
 FIG, 57. THE PTEKVCOID MTSCI.KS. 
 
 cartilage to the sliding of the condyle forward on to the eminentia articularis 
 when the mouth is opened. The only apparent use of the interarticular cartilage 
 is, when the mouth is opened, to furnish a cup concavity for the condyle while 
 this latter is gliding over the convex eminentia articularis. (Fig. 58.) 
 
 A cracking noise on opening the mouth is frequently both a subjective and 
 an objective symptom. This noise is beyond doubt produced by temporary 
 paralysis of this part of the external pterygoid, the condyle overriding the margin 
 of cartilage that normally should precede tire same. The rational treatment 
 would seem to be fixation of the cartilage in the position it occupies when the 
 mouth is open. 
 
 Conclusion : The function of the upper head of the external pterygoid is to 
 make tense and carry forward the interarticular fibre-cartilage. The function 
 of the lower head is to most powerfully draw the jaw forward. 
 
 The loiter /icad of the external pterygoid muscle arises from the outer surface 
 
96 PRACTICAL ANATOMY. 
 
 of the external pterygoid plate, except a small strip at its lower and front part 
 It is inserted into the depression in front of the neck of the condyle. (Fig. 58.) 
 The action of this head is to draw the condyle forward ; at the same time the 
 upper head draws the cartilage forward. 
 
 Concerning the noise patients frequently hear on opening the mouth, I would 
 say I can not now recall ever having read or heard a rational explanation of its 
 occurrence. The theory I advance above is more for the purpose of getting the 
 student aroused to the necessity of learning the origins and insertions of the 
 pterygoids than for mere theorizing. If I succeed even in this, the object of this 
 paragraph will have been accomplished. I found a cadaver in which the crack- 
 ing noise attended every time the mouth was passively opened. On dissection 
 I found the cartilage had contracted inflammatory adhesions to the dome of the 
 glenoid cavity. It was on this single case I founded the theory above advanced, 
 in lieu of an explanation for those noises in the temporo-mandibular articulation 
 concerning which every physician and dentist has been consulted by solicitous 
 
 EMINENTIA ARTICULARIS 
 
 POSTERIOR GLENOID TUBERCLE 
 
 CORONOID PROCESS 
 
 GLENOIO SYNOVIAL CAVITIES 
 
 Interarticular flbro-cartil- 
 age into which is in- 
 serted the upper head of 
 the external pterygoid 
 
 Insertion of the lower head 
 of the external pterygoid 
 
 Insertion of the deep layer 
 of the masseter muscle 
 
 Insertion of the superficial 
 layer of the masseter mus- 
 cle 
 
 FIG. 58. SCHEMATIC. TEMPORO-MANDIBULAR ARTICULATION. 
 
 This is assumed to represent the normal relation of condyle of mandible, and interarticular cartilage to the 
 * eminentia articularis when the mouth is closed. 
 
 patients. A single case, however, is a mere bagatelle ; numerous cases by 
 different observers will be necessary to give the theory scientific sanction. 
 
 /// dislocation of the condyle of the mandible, what muscles must be overcome / 
 
 Practically all. Theoretically, the posterior part of the temporal and the deep 
 portion of the masseter. As a matter of philosophy, however, malposition of 
 the head of a bone immediately sets up tonic contraction in all the muscles of 
 the group, since pain in the joint is reported to the brain and contraction follows 
 in all the muscles in the articular nerve circuit. See Hilton's law in the intro- 
 ductory chapter. 
 
 The temporal muscle has practically two portions : an anterior and a pos- 
 terior. The latter pulls the jaw backward ; the former, acting alone, would pull 
 the jaw forward. 
 
 What are tJie propositions in tlic nerve -supply to the mitsc/cs of mastication f 
 
 They are : 
 
 i. Nerve-supply, sensory, both to the pulp of the teeth and to the gum 
 
 
THE HEAD AND NECK. 
 
 97 
 
 EMINENTIA ARTICULARIS 
 
 Interarticular flbro- 
 cartilage 
 
 MANOIBULAR CONDYLE 
 
 FIG. 59. SCHEMATIC. TEMPORO-MANDIBULAR ARTICULATION. 
 
 This is assumed to represent relation of condyle and cartilage to eminentia articularis when the mouth is 
 open. Here both condyle and cartilage slide forward on to the eminentia articularis ; the former 
 by action of the lower, the latter by action of the upper, head. 
 
 EMINENTIA ARTICULARIS 
 
 Upper head of external 
 pterygoid 
 
 Lower head of external 
 pterygoid 
 
 GLENOID SYNOVIAL CAVITY 
 
 CONDYLE UNATTENDED BY THE CARTILAGE ON 
 THE EMINENTIA ARTICULARIS 
 
 FIG. 60. SCHEMATIC. TEMPORO-MANDIBULAR ARTICULATION. 
 
 This is assumed to' represent abnormal relation of condyle and cartilage to eminentia articularis in those 
 cases where the nerve-twig that supplies the upper head of the external pterygoid muscle is paralyzed. 
 A cracking noise on opening the mouth is a symptom. Here the cartilage remains back in the 
 glenoid, there being nothing to pull it forward. The condyle slips over the thick margin and pro- 
 duces the noise. 
 
98 PRACTICAL ANATOMY. 
 
 covering the same. This comes from the fifth cranial nerve, through dental and 
 gingival branches respectively. 
 
 2. Nerve-supply, motor, to the muscles that elevate the jaw, and sensory, to 
 the skin covering these muscles. This is from the fifth cranial nerve. 
 
 3. Nerve-supply, sensory, to the articulation moved by the muscles of 
 mastication the temporo-mandibular articulation. This is from the auriculo- 
 temporal branch of the fifth cranial nerve. This is explained by Hilton's law. 
 
 4. Nerve-supply, sensory, to the roof of the mouth. This is from the fifth 
 through Meckel's ganglion. Also the sensory nerve-supply to the tongue. 
 The greater part of this is from the fifth nerve through the lingual branch. 
 
 5. Nerve-supply to the inner nose, or that part of the system that selects 
 food by the sense of smell. The sensory part of this is in great part from the 
 fifth nerve, through Meckel's ganglion. The special sense of smell is from the 
 olfactory or first cranial nerve. 
 
 6. Nerve-supply concerned in deglutition. Here a separate system, the 
 digestive, begins, as is evidenced by a radical change in the nerve-supply. The 
 muscles of the soft palate and pharynx are supplied by the pharyngeal plexus, 
 the principal factors in which are the sympathetic and vagus nerves ; these 
 nerves supply all the other organs of the digestive tract. 
 
 What is the salivary system ? 
 
 This system consists of the salivary glands, the parotid, the submaxillary, 
 the sublingual, and their capsules, their nerve-supply, principally sympathetic, 
 and their blood-supply. The latter is derived from the main artery of the 
 region in which the glands are found. 
 
 THE SOFT PALATE. 
 
 1. Prevents rcgurgitation of food into the mouth. (Fig. 64.) 
 
 2. Prevents passage of ingesta into the posterior nares. 
 The structures concerned are the following : 
 
 1. The palato-glossus muscle. Nerve-supply, pharyngeal plexus. 
 
 2. The palato-pharyngeus muscle. Nerve-supply, pharyngeal plexus. 
 
 3. The levator palati muscle. Nerve-supply, pharyngeal plexus. 
 
 4. The tensor palati muscle. Nerve-supply, otic ganglion. 
 
 5. The azygos uvulae. Nerve-supply, pharyngeal plexus. 
 
 To see the action of the palato-glossus muscle on the living subject, make 
 prolonged effort to depress the tongue. When the patient is on the verge ot 
 nausea, you will see the anterior pillars of the fauces spread out and draw the 
 tongue closely under the palatine arch. This is, then, their action : during 
 swallowing, after the bolus passes the initial part of the faucial passage, the 
 tongue is forced under this arch to prevent regurgitation, while the constrictors 
 of the pharynx are contracting on the food. During the same act the palato- 
 pharyngei spread in such a way as to protect the upper pharynx and posterior 
 nares, acting with the levator palati ; the circumflexus tightens the soft palate. 
 
 The levator palati (Fig. 65) arises from the cartilage of the Eustachian tube, 
 and from the under surface of the petrous portion of the temporal bone. It is 
 inserted into the soft palate near the mid-line. 
 
 The circumflexus (Fig. 65), or tensor palati, arises from the scaphoid fossa 
 of the sphenoid bone. (Fig. i i.) The tendon passes around the hamular pro- 
 cess of the internal pterygoid plate and is inserted into the median rap he of the 
 soli palate. Some of its fibres are also inserted into the posterior margin of the 
 hard palate. 
 
 The azygos uvulae (Fig. 65) consists of some muscular fibres extending 
 from the posterior nasal spine to the end of the a/ygos uvulae. (Fig. 1 1.) 
 
THE HI'. AH AND NECK. 
 
 99 
 
 //6>7t.' is the pharyngecU plexus formed and wJiat docs it supply f 
 
 Tliis plexus is formed by the union of branches from 
 
 1. The superior cervical ganglion of the sympathetic. 
 
 2. The glosso-pharyngeal nerve, the ninth cranial nerve. 
 
 3. The pneumogastric or vagus nerve, the tenth cranial nerve. 
 
 4. The superior laryngeal nerve, a branch of the vagus. 
 
 This plexus supplies the mucous membrane and muscles of the pharynx and 
 all the muscles of the soft palate except the tensor palati, which receives its 
 nerve-supply from the otic ganglion. 
 
 The pharyngeal plexus may be seen on your dissection on the outer surface 
 of the middle and inferior constrictors of the pharynx. 
 
 What functions may be rationally attributed to the soft palate as a ivlwlc ? 
 
 Its principal function seems to be to direct food to the stomach and protect 
 the other cavities communicating with the pharynx from invasion by the food, 
 (i) The anterior pillars of the fauces and the tongue prevent regurgitation into 
 the mouth. (2) The posterior pillars of the fauces prevent regurgitation into 
 the nose through the posterior nares. (3) The epiglottis protects the larynx. 
 (4) The levator palati forms a temporary roof over the pharynx during deglu- 
 tition, and thereby protects the Eustachian tube. (5) The tensor palati opens 
 the Eustachian tube during deglutition. 
 
 THE PHARYNX. 
 
 This cavity is situated behind the nose, mouth, and larynx. It connects the 
 mouth with the oesophagus. It is in communication with : 
 
 1. The larynx, which is guarded by the epiglottis. 
 
 2. The oesophagus, its downward continuation to the stomach. 
 
 3. The tympanum, through the Eustachian tube. 
 
 4. The nose, by the posterior nares. 
 
 5. The mouth, being partially shut off by the fauces. The proper muscles 
 of the pharynx are: (i) The superior constrictor pharyngis. (2) The middle 
 constrictor pharyngis. (3) The inferior constrictor pharyngis. (4) The stylo- 
 pharyngis muscle. (5) The palato-pharyngeus muscle. 
 
 The inferior constrictor you will find arising from (i) the cricoid cartilage ; 
 (2) the oblique line of the thyroid; (3) the inferior cornu of the thyroid. It 
 is inserted into the fibrous raphe. (Fig. 62.) 
 
 The middle constrictor arises from the cornua of the hyoid bone, and from 
 the stylo-hyoid ligament. (Fig. 62.) It is inserted into the median raphe, the 
 fibres being disposed as follows : (i) The inferior fibres extend downward and 
 are overlapped by the inferior constrictor ; (2) the superior fibres extend upward 
 and overlap the superior constrictor in part ; (3) the middle fibres extend hori- 
 zontally. (Fig. 62.) 
 
 The superior constrictor muscle of the pharynx (Fig. 62) is pale and 
 thin in comparison with the inferior constrictor. The reason of this will be 
 appreciated when you understand the mechanism of deglutition. Growth is the 
 correlative of function : the function of the inferior constrictor is vigorous con- 
 traction, hence its roborous fibres ; on the other hand, the function of the superior 
 constrictor is a retaining bag, hence its predominance of connective over muscular 
 tissue. 
 
 This muscle has the following origins, u;hk:U ae ,\vcl ; sl)<-un>iri figure. 62 : (i) 
 From the internal pterygoid plate, lovcr tluVd, and .its ha.rii'.lar process; (2) 
 
IOO 
 
 PRACTICAL ANATOMY. 
 
 from the pterygo-mandibular ligament ; (3) from the posterior fifth of the mylo- 
 hyoid ridge (Fig. 9) ; (4) from the side of the tongue. The muscle is inserted 
 into the pharyngeal spine of the occipital bone and into the median raphe. 
 
 Stylo-hyoid 
 
 Ligament urn pharyngeum 
 
 XI 
 
 Posterior belly of 
 digastric 
 
 Sterno-mastoid 
 
 Rectus capitis 
 anticus major 
 
 Etylo-pharyngeus 
 
 Stylo-glossus 
 
 Internal pterygoid 
 
 SUPERIOR 
 CERVICAL 
 GANGLION 
 
 Middle constrictor 
 
 Cummon carotid 
 artery 
 
 Inferior constrictor 
 
 GANGLION 
 THYROIDEUM 
 (VARIETY) 
 
 THYROID GLAND 
 
 Inferior thyroid 
 
 artery 
 Subclavian artery 
 
 RECURRENT 
 LARYNGEAL 
 NER VE 
 
 Internal carotid' 
 
 artery 
 
 RIGHT 
 
 SYMPATHETIC 
 
 Oceiii Hal artery 
 
 Posterior belly of 
 digastric 
 
 DESCENDENS 
 HYI'OGLOSSI 
 
 Common carotid 
 artery 
 
 Sterno-mastoid 
 
 TWIG OF 
 RECURRENT 
 
 LARYNGKAL TO 
 
 PHARYNGEAL 
 
 PLEXUS 
 
 Thyroid axis 
 
 INFERIOR 
 CERVICAL 
 
 GANGLION 
 
 RECURRENT 
 LARYNGEAL 
 
 PLEXUS GULJE 
 
 RIGHT 
 PNEVMOGASTRIC 
 
 Thoracic aorta 
 
 Crus of diaphragm . 
 
 FlG. 6l. DlSTRIHUTION OF THE PNEUMOGASTRIC Xl.KVK, VI K\VKI > 1 ROM 11K1IIND. (Krause.) 
 
 What can you say of tlic structure of tlic pliaryn.v f 
 
 It has three- coats : ;i ;,V/Y,VW.V,, vb.idi is continuous with the mucous membrane 
 of the cavities-with which the ^haCrya>: communicates ; a muscular coat, special- 
 
THE HEAD AND NECK. 
 
 101 
 
 ized as constrictors and elevators of the pharynx to facilitate deglutition ; a fibrous 
 coat, the pharyngeal aponeurosis, situated between the mucous and muscular 
 coats, for strength and support. This is also called the pharyngeal aponeurosis. 
 
 Between what two points docs the pharynx extend ? 
 
 From the base of the skull to the cricoid cartilage. 
 
 What is the pliaryngeal tonsil, and where is it located ? 
 
 It consists of a mass of lymphoid tissue similar to that found in the tonsil. 
 It is located on the back part of the pharynx, between the Eustachian orifices. 
 
 INTERNAL PTERYGOID PLATE 
 Superior constrictor 
 
 Pterygo-mandibular 
 
 ligament 
 Stylo-hyoid ligament 
 
 Middle constrictor 
 
 Stylo-pharyngeua 
 
 Inferior constrictor 
 
 Thyroid cartilage 
 
 Crioo-thyroid 
 Crieoid cartilage 
 
 FIG. 62. THE MUSCLES OF THE PHARYNX. 
 
 Distinguish between pJiaryngeal fascia and pharyngeal aponeurosis. 
 
 The fascia is behind the pharynx. It is the fourth layer of deep cervical 
 fascia continued upward. The aponeurosis is one of the proper coats of the 
 pharynx, located between the mucous and the muscular coats. 
 
 What important structures do yon find between the superior and middle constric- 
 tors of the pharynx ? 
 
 The glosso-pharyngeal nerve and the stylo-pharyngeal muscle. (Fig. 63.) 
 
 What do you find between the middle and inferior constrictors of the pharynx ? 
 
 The superior laryngeal branch of the pneumogastric nerve, and the superior 
 laryngeal branch of the superior thyroid artery. (Fig. 63.) 
 
102 
 
 PR A (. 'TICAL ANA TOMY. 
 
 Describe the /-'iistac/iia/t tube. 
 
 It conveys air from the pharynx to the middle ear. You may see the 
 pharyngeal orifice on the posterior wall of the pharynx, in line with the inferior 
 turbinated bone. You will find the tympanic orifice in the anterior wall of the 
 tympanum, forming the lower of the two compartments of the canalis musculo- 
 tubarius. This you will understand when you dissect the middle ear and the 
 petrous stage of the seventh nerve. The tube is an inch and a half long from 
 the posterior wall of the pharynx to the anterior wall of the tympanum. The tube 
 
 Fn;. 63. MUSCLES OF THE PHARYNX. 
 
 I. Orbicularis oris. 2. Pterygo-maxillary ligament. 3. Mylo-hyoideus. 4. Os hyoides. 5. Thyro- 
 hyoicl ligament. 6. Pomum Adami. 7. Cricoid cartilage. 8. Trachea. 9. Tensor palati. 10. Levator 
 palati. II. Glosso-pharyngeal nerve. 12. Stylo-pharyngeus. 13. Superior laryn<*eal nerve and 
 artery. 14. External laryngeal nerve. 15. Crico thyroideus. 16. Inferior laryngeal nerve. 17. 
 Esophagus. 
 
 has a bony part in the petrous portion of the temporal bone one-half of an inch 
 long ; it has a fibro-cartilaginous part one inch long. 
 
 Has the cartilaginous tube any practical importance as a guide in dissection f 
 
 Yes ; it projects between the origins of the levator palati and tensor palati. 
 
 Give the origins of t/ic levator palati and tlie tensor palati, and show their re- 
 lation to tlic I'.iistac/iian tube. 
 
 (i) The levator palati (Fig. 1 1) arises from the petrous part of the temporal 
 bone and from the lower margin of the Kustachian tube. This muscle you 
 find, then, behind the tube in dissecting, to the inner side. The tensor palati 
 (Fig. 1 1 ) arises from the spine of the greater ala of the sphenoid, from the 
 scaphoid fossa, and from the cartilage of the F.ustachian tube, and is in relation 
 
THE HEAD AND NECK. 
 
 103 
 
 with the external surface of the internal pterygoid plate internally, and with the 
 internal pterygoid muscle externally ; the tendon turns inward around the 
 hamular process, and is inserted into the aponeurosis of the soft palate and into 
 the under surface of the horizontal plate of the palate bone. This muscle you 
 will find in front of and to the outer side of the cartilaginous part of the 
 Eustachian tube. 
 
 Wliat is tlic salpingo-pJiaryngcus muscle ? 
 
 A name by which those fibres of the palato-pharyngeus muscle are desig- 
 nated that arise from the cartilaginous part of the Eustachian tube. 
 
 Name all the muscles attached to the Eustachian tube. 
 
 (i) The levator palati ; (2) the tensor palati ; (3) the salpingo-pharyngeus, 
 or the Eustachian part of the palato-pharyngeus ; (4) the tensor tympani. 
 
 FIG. 64. MEDIAN SECTION OK MOUTH, PHARYNX, AND LARYNX. 
 
 Left nostril. 2. Upper lateral cartilage. 3. Inner portion of lower cartilage. 4. Superior turbinated 
 bone and meatus. 5. Middle turbinated bone and meatus. 6. Inferior turbinated bone and meatus. 
 7. Sphenoid sinus. 8. Posterior nasal fossa. 9. Internal orifice or pavilion of Eustachian tube. 
 10. Velum palati. II, II. Vestibule of mouth. 12. Palatine vault. 13. Genio-glossus muscle. 
 14. Genio-hyoid. 15. Mylo-hyoid. 16. Anterior pillar of velum palati. 17. Posterior pillar. 18. 
 Tonsil. 19. Circum vail ate papillse of tongue. 20. Cavity of larynx. 21. Ventricle. 22. Epiglottis. 
 23. Ilyoid bone. 24. Thyroid cartilage. 25. Thyro-hyoid membrane. 26. Posterior portion of 
 cricoid cartilage. 27. Anterior portion. 28. Crico-thyroid membrane. 
 
 Ho a' is the pharynx innervated ? 
 
 From the pharyngeal plexus, located on the outer surface of the middle and 
 inferior constrictor muscles and formed by the vagus, glosso-pharyngeal, and 
 by branches from the superior cervical ganglion of the sympathetic. 
 
 Give the attachments of the pharynx. 
 
 The sphenoid (Eig. 11), the pharyngeal spine of the occipital, the petrous 
 portion of the temporal, the Eustachian tube, internal pterygoid plate, posterior 
 nares, mouth and larynx, prevertebral fascia, and oesophagus. 
 
 The rectus capitis anticus major arises from the anterior tubercles of the 
 transverse processes of the third, fourth, fifth, and sixth cervical vertebrae. It is 
 inserted into the under surface of the basi-occipital part of the occipital bone. 
 
104 PRACTICAL ANATOMY. 
 
 The muscle flexes the head. Its nerve-supply is from the first and second 
 cervical. 
 
 The rectus capitis anticus minor, a small muscle, arises from the upper 
 part of the lateral mass in front of the articular process of the atlas. It is 
 
 Fharyngeal 
 apoueurosis 
 
 Levator palati 
 
 Tensor palati 
 
 Azygos uvulae 
 Hamular process 
 
 TONGUE 
 
 EUSTACHIAN TUBE 
 Levator palati 
 
 Palato-pharyngeus 
 
 Superior constrictor 
 
 Crico-arytenoideu 
 posticua 
 
 EPIGLOTTIS 
 
 Thyroid cartilage 
 
 Cricoic" cartilage 
 
 TRACHEA 
 
 ISOPHAGUS 
 
 FIG. 65. VIKW OF MUSCLES OF SOFT PALATE, AS SKEN FROM WITHIN THE PHARYNX. 
 
 (Modified from Bourgcry.) 
 
 inserted into the basilar process of the occipital bone, posterior to the preceding 
 muscle. The muscle acts synergistically with the rectus capitis anticus major. 
 
 The rectus capitis lateralis arises from the lateral mass of the atlas. It is 
 inserted into the jugular process of the occipital bone. Its action is to flex the 
 head laterally. This and the preceding muscle are supplied by the first cervical 
 nerve. 
 
 
THE HEAD AND NECK. 
 
 The longus colli. 
 
 Origin. i. From bodies of sixth and seventh cervical and first, second, 
 
 and third dorsal. 
 
 Insertion. 2. Into the bodies of the second, third, and fourth cer- 
 vical. 
 
 w ( Origin. I. Anterior tubercles of transverse processes of third, fourth, 
 
 and fifth cervical. 
 " I Insertion. 2. Tubercle on anterior arch of the atlas. 
 
 Rsetus capitis lateralis 
 
 Rectus capitis anticus 
 major 
 
 Origin of rectus capitis 
 anticus major 
 
 Scalenus medius 
 
 Scalenus antlous 
 
 Scalenua posticus 
 
 Rectus capitis later- 
 alis 
 
 Rectus capitis anti- 
 cus minor 
 
 Intertransyersalis 
 anterior 
 
 Intertransversalis 
 posterior 
 
 Longus colli 
 
 Insertion of scalenus 
 anticus 
 
 Scalenus medius 
 
 Scalenus posticus 
 
 FIG. 66. THK MUSCLES OF THE FRONT OF THE NECK. 
 
 '* S f Origin. i. Bodies of first, second, and third dorsal vertebrae. 
 . 2* < Insertion. 2. Anterior tubercles of transverse processes of fifth and 
 
 C iJ I . , 
 
 J Q i. sixth cervical. 
 
 These muscles are supplied by the anterior divisions of the cervical nerves. 
 The action is evident : flexion direct, lateral, or combined in rotation. 
 
io6 
 
 PRACTICAL ANA TOM}. 
 
 THE LARYNX. 
 
 The upper part of the respiratory tract is called the larynx. Its downward 
 continuation into the neck and thorax is the trachea. The essential organ of 
 voice is a vocal cord on each side of a chink called the rima glottidis. The 
 greater part of the larynx is set aside as a protective for the delicate vocal cords. 
 
 BODY OF HYOID BONE 
 Thyro-hyoid ligament 
 
 Cartilage triticea 
 Foramen for superior 
 
 laryngeal nerve 
 Median portion of thyro- 
 
 hyoid membrane 
 
 SUPERIOR CORNU OF THYROID 
 
 CARTILAGE 
 
 MEDIAN NOTCH OF THYROID 
 CARTILAGE 
 
 Fomum Adami 
 
 OBLIQUE LINE OF THYROID 
 CARTILAGE 
 
 Crico-thyroid membrane 
 
 INFERIOR CORNU OF THYROID 
 CARTILAGE 
 
 THIRD RING OF TRACHEA 
 
 OBLIQUE LINE BELOW SUPERIOR 
 
 TUBERCLE 
 WING OF CARTILAGE BEHIND 
 
 OBLIQUE LINE 
 
 OBLIQUE LINE ABOVE INFERIOR 
 TUBERCLE 
 
 ANTERIOR BORDER OF INFERIOR 
 CORNU 
 
 FIG. 67. FRONT VIEW OF THE CARTILAGES OK THE LARYNX. (Modified from Bourgery and Jacob.) 
 
 POSTERIOR SURFACE OF ARYTENOID 
 
 MUSCULAR EXTERNAL ANGLE 
 Crioo-arytenoid joint 
 
 POSTERIOR SURFACE OF CRICOID 
 CARTILAGE 
 
 Longitudinal fibres of oesophagus 
 
 CORNICULUM LARYNCIS 
 
 Arytenoideus muscle 
 
 Crieo-arytenoideus posticus muscle 
 
 Crioo-arytenoideus posticus muscle 
 
 ARTICULAR SURFACE FOR INFERIOR CORNU 
 OF THYROID CARTILAGE 
 
 FIG. 68. BACK VIEW OF THE CRICOID AND AKYTKNOID CARTII.ACKS. (Modified from Bourgery 
 
 and Jacob.) 
 
 A minor part of the larynx is set aside to move the vocal cords. To gain a 
 comprehensive idea of the larynx in your dissection, you must find on your 
 dissection the following structures : 
 
 1. The thyroid cartilage and hyoid bone. (Fig. 67.) 
 
 2. The thyro-hyoid membrane and median notch of thyroid cartilage. 
 
THE HEAD AND NECK. 
 
 107 
 
 3. The cricoid cartilage and crico-thyroid membrane. (Fig. 67.) 
 
 4. The arytenoid cartilages surmounting the cricoid cartilages. 
 
 5. The epiglottis in the retiring angle of the thyroid cartilage. (Fig. 69.) 
 
 6. The mucous membrane of the larynx. 
 
 7. The superior laryngeal nerve of the vagus nerve. (Figs. 63 and 71.) 
 
 8. The inferior laryngeal nerve (the recurrent branch figure 71) of the 
 
 vaeus. 
 
 GREATER CORNU OF HYOID 
 
 BONE 
 BODY OF HYOID BONE 
 
 Thyro-hyoid ligament 
 
 EPIGLOTTIS 
 
 Median notch 
 
 Origin of thyro-epiglottic 
 
 ligament 
 POSTERIOR EDGE OF THYROID 
 
 CARTILAGE 
 
 Origin of thyro-aryte- 
 noideus muscle 
 
 INFERIOR CORNU 
 
 SMALLER CORNU OF HYOID 
 BONE 
 
 CARTILAGO TRITICEA 
 
 SUPERIOR CORNU OF THYROID 
 CARTILAGE 
 
 RIGHT ALA OF THYROID 
 CARTILAGE 
 
 False vocal cord 
 True vocal cord 
 
 Origin of thyro-epiglot- 
 tideus muscle 
 
 FIG. 69. POSTERIOR VIEW OF THYROID CARTILAGE WITH EPIGLOTTIS. 
 
 9. The superior laryngeal artery, a branch of the superior thyroid artery. 
 (Fig. 28.) 
 
 10. The sympathetic nerve with the laryngeal arteries. 
 
 1 1. The inferior laryngeal artery, a branch of the inferior thyroid. (Fig. 28.) 
 
 1 2. The vocal cords true and false. 
 
 13. The ventricle, the space between true and false cords. 
 
 Thyro-arytenoideus muscle 
 
 Attachment of erico-thyroid muscle 
 
 ANTERIOR SURFACE OF ARYTENOID CARTILAGE 
 
 Cut edge of eapsular ligament 
 Lateral crico-arytenoid muscle 
 
 MUSCULAR EXTERNAL ANGLE OF ARYTENOID 
 CARTILAGE 
 
 Lateral crico-aryteuoid muscle 
 CRICOID CARTILAGE 
 
 FIG. 70. FRONT VIEW OF THE CRICOID AND ARYTENOID CARTILAGES. 
 
 and Jacob.) 
 
 (Modified from Bourgery 
 
 14. The intrinsic muscles of the larynx. 
 
 15. The relation of the epiglottis to the tongue. 
 
 The thyroid cartilage (Fig. 67) has two alae united in the mid-thyroid line. 
 The result of this union gives us the pomum Adami in front, and the retiring or 
 receding angle of the thyroid cartilage behind. (Fig. 69.) The former is a 
 guide in surgical operations on the larynx and trachea ; the latter is of great im- 
 portance in learning the anatpmy and physiology of the vocal cords. Along the 
 
io8 
 
 PRACTICAL ANATOMY. 
 
 superior border of the thyroid cartilage, in the mid-line, you will see the thyroid 
 median notch. Each thyroid ala has a superior cornu and an inferior cornu. 
 The inferior cornu articulates with the cricoid cartilage, forming the crico-thyroid 
 articulation. (Fig. 67.) The superior cornu gives attachment to the lateral 
 thyro-hyoid ligament. The outer surface of the ala has an oblique line, limited 
 above and below by a superior and inferior tubercle respectively. (Fig. 67.) 
 
 The retiring angle of the thyroid cartilage (Fig. 69) gives origin to: (i) 
 The epiglottis ; (2) the false vocal cords ; (3) the true vocal cords ; (4) the 
 thyro-arytenoid muscle ; (5) the thyro-epiglottideus muscle. 
 
 The cricoid cartilage (Figs. 68 and 70) forms, as you will see, a complete 
 ring. It is very narrow in front ; quite wide behind. The arytenoid cartilages 
 
 GREATER CORNU OF 
 
 HYOID BONE 
 CARTILAOO TRITICEA 
 
 SUPERIOR CORNU OF 
 THYROID CARTILAGE 
 
 BRANCH TO LATERAL 
 CRICO ARYTENOID 
 AND TBYRO-ARYTE- 
 .VOID MUSCLES 
 BKANCB JOINING THE 
 SUPERIOR LARYN- 
 GEALKERVR 
 Crico-arytenoldeu* 
 posticus muscle 
 INFERIOR CORNU OF 
 THYROID CARTILAGE 
 
 FORAMEN C/EOUM 
 BASE OF TONGUE 
 
 EXTERNAL LARYN- 
 GJKAL NERVE 
 
 INTERN A L LA R YN- 
 <;I:AL NERVE 
 
 Cut edge of thyro- 
 hyoid membrane 
 
 AryteuoideuB muacle 
 
 RECURRENT 
 LARYNOEAL 
 NER VJ 
 
 FIG. 71. NERVES OF THE LARYNX. (Posterior view.) 
 
 rest upon the superior border of the cricoid, behind, forming a movable articula- 
 tion, called the crico-arylenoid. 
 
 The arytenoids are small. You must learn the following geometrical de- 
 scription of the arytenoids before you can dissect the larynx understandingly, 
 much less understand the action of the arytenoids : 
 Apex, obtruncate and points backward and inward. 
 Base, articulates with the cricoid cartilage. (Fig. 68.) 
 Posterior surface is occupied by the arytenoicleus muscle. (Fig. 68.) 
 Anterior surface for attachment of false cords and thyro-arytenoideus. (Fig. 
 
 /o.) 
 
 Internal surface is covered by mucous membrane. 
 
 Anterior angle, processus vocalis for insertion of true vocal cord. (Fig. 68.) 
 
THE HEAD AND NECK. 
 
 109 
 
 External angle for insertion of posterior and lateral crico-arytenoid muscles. 
 The intrinsic muscles are as follows : 
 
 1. The thyro-arytenoideus. (Fig. 70.) 
 
 2. The crico-arytenoideus lateralis. (Fig. 70.) 
 
 3. The crico-arytenoideus posticus. (Fig. 69.) 
 
 4. The arytenoideus. (Fig. 69.) 
 
 5. The crico-thyroid. (Fig. 27.) 
 
 The intrinsic muscles and the mucous membrane are supplied by (i) the 
 superior laryngcal branch of the pneumogastric ; (2) the inferior laryngeal 
 branch of the pneumogastric ; (3) the sympathetic nerves accompanying the 
 superior and inferior laryngeal arteries ; they take the name of the arteries. 
 
 The superior laryngeal nerve (Fig. 71) supplies the mucous membrane and 
 the crico-thyroid muscle. 
 
 Epiglottis 
 
 Cut edge of hyo-epiglottidean 
 
 ligament 
 
 SECTION THROUGH BODY OF HYOID 
 BONE 
 
 Peri glottis 
 
 Cut edge of thyro-hyoid 
 membrane 
 
 Thyro-epiglottideus muscle 
 
 SECTION OF THYROID CARTILAGE 
 Thyro-arytenoideuB muscle 
 
 Crioo - arytenoideua lateralis 
 muscle (the pointer crosses 
 erieo-thyroid membrane) 
 
 CRICOID CARTILAGE 
 
 Aryteno-epiglottidean fold 
 Aryteno-epiglottideus muscle 
 
 Arytenoideus muscle 
 
 Crleo-arytenoideus postious 
 
 Recurrent laryngeal nerve 
 
 FIG. 72. SIDE VIEW OF THE MUSCLES AND LIGAMENTS OF THE LARYNX. 
 
 The inferior laryngeal supplies the remaining muscles. 
 
 The false vocal cord extends from the retiring angle of the thyroid cartilage 
 (Fig. 69) to the anterior surface of the arytenoid cartilage. (Fig. 70.) 
 
 The true vocal cord extends from the retiring angle of the thyroid cartilage 
 (Fig. 69) to the anterior angle of the arytenoid cartilage. (Fig. 70.) 
 
 The chink, or rima glottidis, is the space between the two true vocal cords. 
 This chink consists of two parts a respiratory or posterior and a vocalizing or 
 anterior. 
 
 The thyro-arytenoid muscle (Fig. 69) extends from the retiring angle of 
 the thyroid cartilage to the anterior surface of the arytenoid cartilage. (Fig. 70.) 
 The action of this muscle is to pull the arytenoid cartilage forward and thereby 
 relax the vocal cords. 
 
 The arytenoid muscle (Fig. 71) extends from the posterior surface of one 
 
no PRACTICAL ANATOMY. 
 
 to that of the other arytenoid cartilage. It approximates the vocal cords by 
 drawing the arytenoids together. 
 
 The crico-arytenoideus lateralis (Fig. 72) arises from the upper border 
 of the side of the cricoid cartilage. It is inserted into the external angle of the 
 base of the arytenoid cartilage. The action is to draw the vocal cords together 
 and close the glottis. 
 
 The crico-arytenoideus posticus arises on the posterior part of the cricoid. 
 It is inserted into the outer angle of the base of the arytenoid cartilage. This 
 muscle draws the vocal cords apart, and thereby opens the glottis. 
 
 The crico-thyroid muscle arises from the side of the cricoid cartilage. It 
 is inserted into the lower corner of the thyroid cartilage. It tightens the vocal 
 cords. 
 
 Describe the superior laryngeal nerve. (Fig. 71.) 
 
 It is a branch of the ganglion of the trunk of the pneumogastric nerve. It 
 passes behind the internal and external carotid arteries. It is joined by com- 
 municating branches from the sympathetic nerve and the pharyngeal plexus. It 
 divides into an internal and an external branch. The external branch pierces the 
 inferior constrictor of the pharynx near the lower border of the thyroid cartilage 
 (Fig. 63), and is distributed principally to the crico-thyroid muscle ; some few 
 filaments are distributed to the mucous membrane. The internal division, in 
 company with the superior laryngeal artery, passes under the thyro-hyoid 
 muscle (Figs. 27 and 71), pierces the thyro-hyoid membrane, and is distributed 
 to the mucous membrane, communicating here with the recurrent laryngeal 
 nerve. (Fig. 71.) 
 
 Describe the course of the recurrent laryngeal nerves. (Fig. 71.) 
 
 The nerve of the right side is given off from the pneumogastric in front of 
 the first stage of the subclavian artery. It passes upward, under, and behind 
 the subclavian artery, then behind the common carotid to the side of the trachea. 
 It lies in a fatty groove between the trachea and oesophagus, and, in company 
 with the inferior laryngeal artery, passes upward, under the inferior constrictor 
 of the pharynx, to the larynx. It is distributed to all the intrinsic muscles of 
 the larynx except the crico-thyroid. The recurrent laryngeal nerve of the left 
 side is given off from the pneumogastric in front of the transverse part of the 
 aortic arch, passes under this vessel behind the obliterated ductus arteriosus, and 
 gains the fatty space between the trachea and oesophagus, and has the same sub- 
 sequent course and distribution as the nerve on the right side. In their course 
 between the oesophagus and trachea these nerves give off branches to these 
 conduits. 
 
 Describe the blood-supply of the larynx. (Fig. 28.) 
 
 The superior laryngeal artery is a branch of the superior thyroid. It accom- 
 panies the superior laryngeal nerve, piercing with this nerve the thyro-hyoid 
 membrane. The inferior laryngeal artery is a branch of the inferior thyroid. It 
 passes behind the inferior constrictor of the pharynx with its accompanying 
 nerves. 
 
 Describe the trachea. 
 
 It is an air conduit, extending from the larynx to the tracheal bifurcation, 
 where the bronchial tubes begin. Compared to the vertebral column, in front of 
 which the trachea lies, it extends from the fifth cervical to the fifth thoracic verte- 
 bra. It is one inch in width and five inches long. 
 
 The structure of 'the trachea fits it admirably for its specific double function 
 (i) of transmitting air inward and (2) of extruding both air and accumulated 
 mucus, bearing crude inhaled impurities. Imperfect rings of cartilage, held 
 together by fibro-elastic membrane possessing some muscular fibres, a rich nerve- 
 ami blood-supply, and a lining of mucous membrane, are the anatomical tissues 
 
THE HEAD AND NECK. in 
 
 that specially qualify the trachea for its important duty. The front part of the 
 trachea is round, the back part flat. The space between the ends of the imper- 
 fect rings of cartilage behind is filled by the musculus trachealis. This consists 
 of transverse and longitudinal unstriped fibres. The arrangement of these is 
 such as to set up a vermicular movement in the trachea when expectoration 
 occurs. 
 
 The nerve-supply of the trachea comes from the vagus and also from the 
 recurrent laryngeal, a branch of the vagus, as this latter nerve lies in the fatty 
 groove between the trachea and oesophagus ; and from the sympathetic, which 
 latter nerves accompany the tracheal arteries, and take the same name. 
 
 The blood-supply of the trachea comes from the inferior thyroid artery, a 
 branch of the thyroid axis of the subclavian artery. (Fig. 36.) The veins join 
 the thyroid plexus of veins. Of the thyroid veins, you will remember, the right 
 opens into the right innominate, the left into the left innominate vein. Each of 
 these has valves where it becomes tributary to the larger vessel. These thyroid 
 veins communicate on the trachea. These are the troublesome vessels in low 
 tracheotomy. 
 
 Relations of the Trachea. If you will review your dissection, you will find in 
 front of the cervical part of the trachea the isthmus of the thyroid gland (Fig. 27), 
 the inferior thyroid veins, the sterno-hyoid and sterno-thyroid muscles (Fig. 27), 
 the deep cervical fascia, superficial fascia, and skin. Behind, the trachea is in rela- 
 tion with the oesophagus. On each side are the common carotid arteries, the infe- 
 rior thyroid artery, the recurrent laryngeal nerve, and the lobes of the thyroid 
 gland. (Fig. 31.) The thoracic part of the trachea, as you will see at a later 
 stage of your work, is covered by the manubrium sterni, the remains of the thymus 
 gland, the left brachio-cephalic vein, the aortic arch, the innominate and left com- 
 mon carotid arteries, and the deep cardiac plexus. Posteriorly is the oesophagus, 
 and laterally the vagus nerves are on each side. 
 
 THE NASAL FOSS.E INTERNAL NOSE. 
 
 Dissection. With a sharp saw cut through (i) the symphysis of the mandible. 
 Then take a sharp knife and cut through the tongue from base to tip in the mid- 
 line, as far forward and downward as the hyoid bone. (2) Let an assistant hold 
 the divided halves of the mandible apart, while you saw through the mid-line of 
 the remainder of the face. (Fig. 64.) Precaution : Before you make the latter 
 cut, observe to which side the septum nasi is deflected ; cut on the opposite side, 
 so as to have the septum intact for study. The cuts have placed before you for 
 study the mouth and nasal fossae. Very little dissection in addition to that already 
 done is necessary. 
 
 The nasal fossae have the following geometrical parts : 
 
 1 . Roof, formed by the nasal bones, the nasal spine of the frontal bone, crib- 
 riform plate of the ethmoid, the under surface of the body of the sphenoid. 
 
 2. A floor (Fig. 74), formed by the hard and soft palate, covered by mucous 
 membrane. The hard palate is formed by the palatine process of the superior 
 maxilla and the horizontal part of the palate bone. 
 
 3. An inner wall (Fig. 74), formed by the septum nasi, covered by mucous 
 membrane. The septum nasi is composed of (i) thevomer ; (2) the vertical plate 
 of the ethmoid ; (3) the cartilaginous septum quadrangular in some, triangular 
 in other cases. 
 
 The outer surface is formed by the nasal bones, the nasal process of the 
 
112 
 
 PR A CTICAL ANA TO MY. 
 
 superior maxilla, the lachrymal, ethmoid, inner surface of superior maxilla, in- 
 ferior turbinated, vertical plate of palate bones, and inner surface of pterygoid 
 
 PTERYGO-PALATINE CANALS 
 
 VIOIAN CANAL 
 
 PTERYGOIO FOSSA 
 EXTERNAL PTERYGOID PLATE 
 
 TUBEROSITY OF PALATE BONE 
 
 FORAMEN OVALE 
 
 INTERNAL PTERYGOiD PLATE 
 
 HAMULAR PROCESS 
 
 SPINE OF PALATE OR POSTERIOR 
 NASAL SPINE 
 
 FIG. 73. THE POSTERIOR NARES. 
 
 NASAL BONE Frontal sinus 
 
 Sphenoidal sinus 
 
 UPPER LATERAL CARTILAGE 
 
 Groove between septa! 
 and upper lateral 
 cartilage 
 
 
 LOWER LATERAL 
 
 THICKENED BORDER OF CARTILAGE RESTING i \ Pouch at uprer 
 
 UPON ANTERIOR NASAL SPINE Incisive papilla \ extremity of Sten- 
 
 SEPTAL CARTILAGE 8on ' 8 canal 
 
 ORIFICE OF EUSTACHiAN 
 
 TUBE 
 SOFT PALATE 
 
 FIG. 74. SECTION SHOWING BONY AND (.'AIM -11 .ACINOI s SKITCM. 
 The dotted line indicates the course of the anterior palatine canal. 
 
 process of the sphenoid bone. This surface is covered by mucous membranr. 
 This must be studied on the dry skull. 
 
 The anterior narcs is the inlet to the nose from the external world. The 
 
THE HEAD AND NECK. 
 
 IT 3 
 
 posterior nares is the opening into the pharynx. (Fig. 73.) Notice: On the 
 outer wall, and even forming part of the same, are the three turbinated bones. 
 
 Study figure 74. Remove the mucous membrane from the septum, and find 
 (i) suture between the vomer and ethmoid ; (2) junction between cartilage and 
 ethmoid ; (3) the naso-palatinc groove on the vomer, containing a nerve and an 
 artery of the same name. The nerve, a branch of Meckel's ganglion, one on each 
 side, passes through the foramina of Scarpa, in the anterior palatine canal (Fig. 
 74), and anastomoses with the anterior palatine nerves, also branches of Meckel's 
 ganglion. (Figs. 53 and 75.) 
 
 The turbinated bones (Fig. 77) are three in number. They occupy the outer 
 wall, as follows fractionally : The superior turbinal, the posterior third ; the middle 
 turbinated, the posterior two-thirds ; the inferior turbinated extends the whole 
 length of the wall. 
 
 NA SA L OLFA CTOR Y 
 FRONTAL SINUS NERVE NERVE 
 
 OLFACTORY NERVE 
 TO SUPERIOR TL'R- 
 JilNA TE BONE 
 
 SPHENOIDAL SINUS 
 
 VIDIAN NERVE 
 
 MECKEL'S 
 
 GANGLION 
 DESCENDING 
 
 PALATINE 
 
 ORIFICE OF EUSTACHIAN 
 TUBE 
 
 NASAL BRANCHES 
 
 POSTERIOR 
 
 PALATINE 
 ANTERIOR 
 
 PA LA TINE 
 MIDDLE PALATINE 
 
 FIG. 75. NERVES OF THE NASAL CAVITY. 
 
 Tlie Etluno-turbinals (Fig. 77). This name is given to the superior and middle 
 turbinals. They belong to the lateral mass of the ethmoid bone. 
 
 The meatuses are three irregular cavities on the outer wall of the nasal 
 fossae. Into them open the nasal duct and the frontal, ethmoidal, maxillary, and 
 sphenoidal sinuses : 
 
 Inferior, receives the nasal duct conveying the tears. 
 
 Middle, receives the openings the antrum, frontal, and anterior ethmoidal cells. 
 
 Superior, the opening of the sphenoidal and posterior ethmoidal cells. 
 
 Describe the nasal mucous membrane. 
 
 It is called pituitary membrane, from an erroneous idea entertained by the 
 ancients that the nasal deflections had their origin in the pituitary body. It is 
 also called the Schneiderian mucous membrane. In the regions of the turbinals 
 and septum it is thick, vascular, and loosely attached to the bone ; in the bottom 
 of the meatuses and in the intramural sinuses communicating with the nasal 
 
H4 PRACTICAL ANATOMY. 
 
 fossae it is thin. It is continuous with the mucous membrane of all the cavities 
 with the nasal fossae communicante. 
 
 Name the arteries that supply the nasal fossa. 
 
 1. The anterior and posterior ethmoidal supply the roof, outer wall, and 
 upper half of the septum. These are branches of the ophthalmic, and leave the 
 orbital cavity by the anterior and posterior ethmoidal foramina. The companion 
 veins have like name, and are tributary to the ophthalmic vein. Infection in this 
 region, then, might extend along the ophthalmic vein to the cavernous sinus, 
 since this vein has no valves. 
 
 2. The spheno-palatine supplies the lower half of the septum, the turbinals, 
 the meatuses, the frontal sinuses, and the antra. The companion veins of these 
 arteries are confluent to the pterygoid plexus on the inner side of the internal 
 pterygoid muscle ; the veins take the same name as the arteries. The pterygoid 
 
 Frontal sinusec 
 
 MIDDLE TURBINAL 
 BONE 
 
 NASAL SEPTUM 
 
 RIGHT ANTRUM 
 
 INFERIOR TURBINAL 
 BONE 
 
 FIG. 76. TRANSVERSE SECTION PASSING THROUGH THE NASAL Foss^: AND ANTRA AT THE 
 POSTERIOR EXTREMITY OF THE MIDDLE TURBINAL BONE. (Seen from the front.) 
 
 plexus communicates with the cavernous sinus by the Vesalian vein. Infection 
 from this region may reach the sinus, since the Vesalian has no valves. 
 
 3. The descending palatine and Vidian arteries, branches of the internal max- 
 illary, supply the nasal fossae. 
 
 What can you say of the nasal mucous membrane in relation to nose bleeding , 
 and in what way may a violent hemorrhage from the nose abort cerebral apoplexy ? 
 
 The venous blood in the mucous membrane of the nose communicates with 
 the superior longitudinal sinus, in the falx cerebri, by an emissary vein which 
 passes through the foramen caecum in front of the crista galli. The nasal mucous 
 membrane is very vascular and quite loosely attached, a condition favoring easy 
 rupture of its vessels. In cerebral congestion of the face the ocular and nasal 
 mucous membranes become engorged, on account of their communication with 
 the sinuses. On account of its lax attachment the vessels of the nasal mucous 
 
THE HEAD AND NECK. 115 
 
 membrane frequently give way, and hemorrhage results. This occurs more fre- 
 quently in children than in adults. 
 
 Describe the nerve-supply to the mucous membrane of the nose. 
 
 1. The olfactory nerves are distributed to the Schneiderian membrane of the 
 upper third of the septum, and to the superior and middle turbinals. 
 
 2. The nasal nerve, a branch of the ophthalmic division of the fifth nerve, 
 supplies the anterior half of the roof, outer wall, and inner wall of the nasal 
 fossae with common sensation. 
 
 3. The upper branches of Meckel's ganglion and the Vidian nerve supply 
 the posterior half of the roof, outer wall and inner wall, and the superior tur- 
 binal. 
 
 4. The anterior palatine branch of Meckel's ganglion on its way down to the 
 roof of the mouth supplies the middle and inferior turbinals. 
 
 Frontal sinus 
 
 Orifice of middle ethmoidal cells 
 
 SUPERIOR TURBINAL BONE 
 Orifice of the posterior ethmoidal cells 
 Orifice of the sphenoidal sinus 
 Sphenoidal sinus 
 
 Orifloe of frontal sinus 
 
 UPPER ORIFICE OF 
 NASAL DUCT 
 
 ORIFICE OF EUSTAOHIAN 
 TUBE 
 
 LOVvER ORIFICE OF NASAL DUCT 
 
 MIDDLE TURBINAL BONE 
 
 INFERIOR TURBINAL BONE ORIFICE OF THE ANTRUM ORIFICE OF INFUNDIBULUM 
 
 FIG. 77. SECTION OF THE NOSE, SHOWING THE TURBINAL BONES AND MEATUSES, 
 WITH THE OPENINGS IN DOTTED OUTLINE. 
 
 5. The naso-palatine branch of Meckel's ganglion supplies the lower and 
 posterior part of the septum. The anterior superior dental nerves supply the 
 inferior turbinated bone, hence a disease of this bone may cause pain in the ear 
 or in any of the teeth. 
 
 The Intramural Sinuses. This is a convenient term by which to distinguish 
 the air-containing cells, in connection with some of the bones of the skull and face, 
 from the dural sinuses in the dura mater, whose use is to contain and convey blood 
 away from the brain. These sinuses are the ethmoid, the sphenoidal, the mastoid, 
 the maxillary or antrum of Highmore, the frontal, mastoid antrum, and mastoid 
 cells. As they all communicate directly or indirectly with the nasal fossae, we 
 will consider them in this place. The mastoid cells communicate with the middle 
 ear, and this with the pharynx by the Eustachian tube. The others communi- 
 cate with the nasal fossae as indicated in figure 77. 
 
 Formation. The intramural cells are formed by absorption of the middle 
 
 
n6 
 
 PRACTICAL ANATOMY. 
 
 or diploic plate of bone. They are lined by mucous membrane. Infection is 
 very liable to occur in these sinuses. The difference between the mucous mem- 
 brane of the sinuses and that of the mouth is this : the latter is more vascular, 
 more hardy, more resisting, both to infection and traumatic causes, on account 
 of its location being such that exposes it to friction. Structure being the 
 correlative of function, an increased blood-supply would logically account for the 
 superior hardihood and less vulnerable character of the mucous membrane of 
 the mouth, and all other regions where friction is a consideration inseparable 
 from the environment. 
 
 Take special notice that 
 
 1. The orifice of the Eustachian tube is on a direct line with the inferior 
 meatus. 
 
 2. A fine straw or bristle can be passed through the infundibulum (Fig. 77) 
 of the frontal sinus, into the middle meatus. 
 
 3. A straw can be passed through the nasal duct into the inferior meatus ; 
 by turning the inferior turbinated bone up, you can easily see the orifice for the 
 nasal duct. 
 
 4. The inferior meatus is located between the floor of the nasal fossae and 
 the inferior turbinated bone, and receives the end of the nasal duct. (Fig. 77.) 
 
 ANTRUM 
 
 POSTERIOR PALATINE GROOVE 
 PALATINE PROCESS 
 
 NASAL PROCESS 
 
 RIDGE FOR MIDDLE TURBINAL 
 
 LACHRYMAL GROOVE 
 
 RIDGE FOR INFERIOR TURBINAL 
 
 NASAL SPINE 
 
 CREST 
 
 ANTERIOR PALATINE GROOVE 
 
 FIG. 78. THE LEFT MANILLA. (Inner view.) 
 
 5. The middle meatus is situated between the inferior and middle turbi- 
 nated bones. It receives the opening for the antrum, frontal sinus, and anterior 
 ethmoidal cells. (Fig. 77.) 
 
 6. The superior meatus is located between the middle and superior turbi- 
 nated bones, and receives the openings for the sphenoidal sinus and for the 
 posterior ethmoidal cells. (Fig. 77.) 
 
 The antrum of Highmore (maxillary sinus] (Figs. 68 and 76) occupies the 
 interior of the body of the superior maxilla. Its medical and surgical importance 
 entitle it to the following analytical consideration : 
 
 1. It has a roof, a thin plate of bone that forms the floor of the orbit. In 
 this roof is the infraorbital nerve and vessels. (Fig. 51.) 
 
 2. A floor formed by the alveolar process of the upper jaw. The fangs of 
 the teeth may produce irregularities of this floor. (Fig. 76.) The surgeon may 
 gain access to the cavity by extracting a first or second molar tooth. 
 
 3. Inner ivall. The importance of this wall is the presence of the normal 
 opening, by which the antrum communicates with the nasal fossae. (Fig. 77.) 
 The surgeon may gain access to the antrum for drainage by this wall. 
 
 4. Anterior wall. On the inner surface of this wall are the anterior superior 
 
THE HEAD AND NECK. 117 
 
 dental canals, containing vessels and nerves for the teeth. (Fig. 51.) On the 
 outer surface of this wall is the infraorbital plexus of nerves, formed by the 
 infraorbital branches of the fifth and seventh nerves. Entrance to the antrum for 
 purpose of drainage is gained by going through this wall too. 
 
 5. Posterior ivall. On this you will find the posterior dental canals for 
 nerves and vessels to the posterior teeth of the superior maxilla. (Fig. 5 I.) The 
 apex of the antrum corresponds to the prominence of the cheek. 
 
 W hat can you say of the size of the antrum of Highmore, or maxillary sinus ? 
 
 It will contain about one ounce of fluid. It is variable in size in different 
 persons. It is longer in the male than in the female. A large bone may have a 
 very small antrum, and vice versa. 
 
 IV hat can you say of the floor of the ai/tniui / 
 
 The floor is the strongest wall. It is uneven on account of the roots of the 
 teeth, the first and second molars being usually those producing the uneven- 
 ness. These tooth-roots may even penetrate the floor of the antrum, and be the 
 exciting cause of disease of the antral mucous membrane. The antrum may be 
 divided into several compartments, or pockets, as they are called, by bony par- 
 titions of variable thickness and height, a circumstance which must always enter 
 
 INFRAORBITAL FORAMEN 
 
 NASAL NOTCH 
 
 CANINE FOSSA 
 
 NASAL SPINE 
 
 INCISIVE FOSSA 
 
 CANINE EMINENCE 
 
 BORDER OF SPHENO-MAX1LLARY 
 
 FISSURE 
 FOR SPHENOID 
 
 ZYGOMATIC SURFACE 
 MALAR PROCESS 
 POSTERIOR DENTAL CANALS 
 
 TUBEROSITY 
 
 FIG. 79. THE l.v.vv MAXILLA. (Outer view.) 
 
 as a prognostic factor in operations to establish drainage on the antrum. The 
 surgeon should ask himself after each operation, " Have I drained the antrum or 
 only a pocket of the antrum ? " A merchant had a wine-cellar flooded with water. 
 He employed a company to remove the water. A hose was thrust through a 
 dark window and the pump started. To the dismay of the merchant, the experts 
 had thrust the hose into a hogshead of wine, and drained the pocket, instead of 
 the cellar. 
 
 What cany 'ou say of the nerve -supply of the antrum ? 
 
 The nerve-supply of the mucous membrane of the antrum comes from the 
 anterior and posterior superior dental branches of the fifth nerve. You will 
 remember this : The dental nerves supply the teeth ; the skin of the lips and 
 cheeks covering these teeth outside ; the gums surrounding these teeth, through 
 small branches called the nervuli gingivales ; and, lastly, the mucous membrane 
 of the antrum. 
 
 Describe the blood-supply of the antrnin f 
 
 The internal maxillary artery gives off branches not only to the teeth (dental 
 branches), but also branches to the gums (gingival branches), and antral branches 
 to the mucous membrane of the antrum. These antral branches are accom- 
 panied by sympathetic nerves. 
 
u8 
 
 PRACTICAL ANATOM\. 
 
 To what is the nasal nerve distributed? 
 
 To the septum, to the outer part of the nose, and to the two lower turbinals. 
 This is a sensory nerve, a branch of the ophthalmic division of the fifth. It is 
 found in the cranial, orbital, and nasal cavities. It traverses the anterior eth- 
 moidal foramen and the nasal slit. 
 
 Where is the olfactory nerve distributed ? 
 
 To the roof of the fossa ; to the superior and middle turbinals ; to the upper 
 half of the septum nasi. (Fig. 75.) 
 
 Where is the spheno-palatine or Meckel 's ganglion ? 
 
 In the spheno-palatine fossa, under the second division of the fifth nerve. 
 It is the source from which the nose and mouth and palate derive their nerve- 
 supply in great part. (Fig. 75.) 
 
 Tlie sensory root of Meckel' s comes from the second division of the fifth, 
 called the spheno-palatine nerves. (Fig. 53.) 
 
 The motor root comes from the seventh or facial nerve, through the large 
 
 FRONTAL SINUS 
 
 NASAL PROCESS OF MAXILLA 
 LACHRYMAL 
 
 LACHRYMAL CANAL 
 
 ORIFICE OF ANTRUM 
 
 INFERIOR TURBINAL 
 
 PALATE BONE 
 
 ANTERIOR NASAL SPINE 
 
 ANTERIOR ETHMOID CANAL 
 POSTERIOR ETHMOID CANAL 
 OPTIC FORAMEN 
 
 OS PLANUM OF ETHMOID 
 
 SPHENO-PALATINE FORAMEN 
 VIDIAN CANAL, LEADING INTO THE 
 
 SPHENO-MAXILLARY FOSSA 
 SPHENOID 
 
 EXTERNAL PTERY60ID PLATE 
 PALATE BONE 
 
 FIG. 80. A SECTION OF THE SKULL, SHOWING THE INNER WALL OF THE ORBIT, THE BASE OF 
 THE ANTRUM, AND THE SPHENO-MAXILLARY FOSSA. 
 
 superficial petrosal. This you can see in a groove under the dura, on the 
 anterior surface of the petrous portion of the temporal bone. The nerve passes 
 behind the Gasserian ganglion, down through the sphenotic foramen. It joins 
 here, at the base of the skull, the large, deep petrosal branch of the carotid 
 plexus. The two now pass through the Vidian canal. The result of the union 
 of the large superficial petrosal of the seventh nerve and the large, deep petrosal 
 of the carotid plexus is the Vidian nerve. (Fig. 53.) The last is the sympathetic 
 root. 
 
 Name the brandies given off by Meckel' s ganglion. (Fig. 53.) 
 (i) Branches to the orbital periosteum; (2) branches to the mucous mem- 
 brane of the nose; (3) anterior palatine to the roof of the mouth (Fig. 55) ; 
 (4) naso-palatine in groove on nasal septum ; (5) branches to the upper pharynx 
 behind luistachian tube. 
 
 I introduce here, by consent of the author, some conclusions on the opening 
 of the infundibulum in relation to the opening for the antrum of Highmore. I 
 have given no special attention to the subject in the dissecting-room ; still, inci- 
 
THE HEAD AND NECK. 119 
 
 dentally, I have verified in seven cases the views of the author of the follow- 
 ing : 
 
 CONTINUED STUDY OF THE RELATIONS OF THE FRONTAL SINUS TO THE ANTRUM. 
 
 BY THOMAS FILLEBROWN, M.D., D.D.S., BOSTON, MASS. 
 PROFESSOR OF OPERATIVE DENTISTRY AND ORAL SURGERY, DENTAL SCHOOL OF HARVARD UNIVERSITY. 
 
 (Read before the American Dental Association, August j, 1897, and reprinted from the '''Dental Cosmos" for 
 
 December, 1897.) 
 
 " Last year I made a report of some observations I had made on the formation 
 of the infundibulum, showing that in many cases it continued directly to, and 
 terminated in the foramen of, the antrum, and that a fold of mucous membrane 
 mentioned by Merke, in 1834, extended above the foramen, forming a pocket, 
 from the bottom of which the opening into the antrum is situated, thus directing 
 any discharge coming down the infundibulum into the antrum, so that, under ordi- 
 nary circumstances, no abnormal discharge from the frontal sinus would escape 
 into the nasal passage until the antrum was filled so as to cause a backward 
 overflow. 
 
 " I mentioned the fact that Tilleaux, about 1840, noticed that of fluid injected 
 into the frontal sinus, a great part flowed into the antrum, and that Dr. Cryer, in 
 the same year, mentioned the same circumstance. He also showed that a probe 
 could be passed from the antrum into the frontal sinus. I also noticed that 
 Byran had mentioned the fact of occasional communications between the cavities, 
 but considered them anomalies, and that Professor Harrison Allen had discussed 
 the proliferation of empyema of the frontal sinus into the antrum. These obser- 
 vations were of isolated cases, and were not proved or considered indicative of 
 the normal anatomy of the parts. 
 
 " I reported that the examination of eight different subjects showed that the 
 infundibulum continued as a deep groove, or tube, open on one side down to the 
 foramen of the antrum, and terminated in it, in every one of the eight cases, and 
 that the pocket described was present in seven of the eight. This seemed to 
 imply that the continuation of the infundibulum to the antral foramen and the 
 presence of the pocket membrane was the normal formation. During the past 
 winter I had opportunity to examine fifteen heads in the Harvard dissecting- 
 room, and found the infundibulum continuing to the foramen of the antrum in 
 every case. The membranous fold was present in every case, except on the left 
 side of one subject. In this case the process was broad and flattened toward the 
 meatus, and, though the mucous fold was absent, the widened process served the 
 same purpose, as it formed a cup-shaped cavity quite as capacious as the pocket 
 on the other side. 
 
 " In another case the mucous fold was thickened and had considerable mus- 
 cular tissue intermingled in its substance. 
 
 " On the right side of this subject the infundibulum was very large, and in 
 place of the ordinary foramen there were two openings, both quite large, fully 
 one-fourth of an inch in diameter. 
 
 " In another case the pockets were large, irregular in form, and deep, the 
 mucous fold completely covering the infundibulum from the foramen of the 
 frontal sinus to the antrum. 
 
 " In one subject the mucous fold was considerably calcified. This condition 
 had obtained to a degree throughout the whole system. This subject was 
 advanced in years. This makes a total of twenty-three cases ; a number, I think, 
 sufficient to establish the fact of the normality of the anatomy of the parts. 
 
 " The very few variations only prove the rule. I hoped to secure the co-opera- 
 
i2o rRACTICAL AX ATOMY. 
 
 tion of others in making further examinations during the winter, but the reprints 
 of my paper were too long delayed, and the dissecting season was passed before 
 I could communicate with anatomists and make the necessary arrangements and 
 have the benefit of the results of the examinations of other subjects." 
 
 THE COVERINGS OF THE BRAIN. 
 
 Those structures intervening between the brain and the outside are brain pro- 
 tectives,and may be called coverings. In number they are three ; in a collective 
 sense, outer, middle, inner. The outer is called the scalp ; the middle, the cal- 
 varium ; the inner, the meninges. As above intimated, each of these three cov- 
 erings is a collective noun, and must be reduced, analytically, to its simplest 
 terms of individual structures. 
 
 The scalp consists of the following layers : 
 
 1. The skin, covered by a thick growth of hair in primitive man. 
 
 2. The superficial fascia, the distribution area where you are to find all the 
 arteries, veins, nerves, and dermal muscles of the scalp. 
 
 3. The occipito-frontalis muscle, consisting of an anterior and a posterior 
 belly, connected by a broad aponeurosis that takes the name of the muscle. 
 
 4. A subaponeurotic layer of connective tissue, which you can account 
 for by consulting a paragraph in the introductory chapter on the non-apposition 
 of anatomical structures. 
 
 There are, then, four layers. The scalp moves .freely. The fibrous covering 
 of the bone is periosteum, and its subperiosteal connective tissue does not differ 
 from like tissue found underlying periosteum everywhere. These two structures 
 do not form integral parts of the scalp because they do not move. 
 
 Dissection. Remove the skin having shaved the head by making cross- 
 incisions on the mid-top of the head, thus +. 
 
 In the superficial fascia of the scalp you are to find the following structures : 
 
 1. The supraorbital nerve and vessels. (Figs. 16 and 18.) 
 
 2. The temporal branches of the seventh nerve. (Fig. 16.) 
 
 3. The auriculo-temporal branch of the fifth nerve. (Fig. 16.) 
 
 4. The temporal arteries superficial and veins. (Fig. 18.) 
 
 5. The great occipital nerve second cervical, posterior division. (Fig. 22.) 
 
 6. The small occipital nerve cervical plexus. (Fig. 22.) 
 
 7. The great auricular nerve cervical plexus. (Fig. 22.) 
 
 8. The posterior auricular artery branch of the external carotid. 
 
 9. The posterior auricular nerve branch of seventh cranial. (Fig. 16.) 
 The above structures you have already found in your dissection of the face 
 
 and neck. 
 
 10. The dermal muscles are as follows (Fig. 14) : 
 
 1. Musculus attrahens aurem draws the ear forward. 
 
 2. Musculus attollens aurem draws the ear upward. 
 
 3. Musculus retrahens aurem draws the ear backward. 
 
 They have origin and insertion as indicated in the figure. They are insig- 
 nificant, and can only be demonstrated in some cases. The function of these 
 muscles is seen in some of the domestic animals the dog, horse, and mule. 
 
 The occipito-frontalis (Fig. 14) has a posterior attachment to the outer two- 
 thirds of the superior curved line of the occipital bone and to the mastoid process 
 of the temporal bone. This muscular belly terminates anteriorly in a broad epi- 
 
THE HEAD AND NECK. 
 
 121 
 
 cranial aponeurosis. Follow this forward to the anterior belly. The anterior 
 belly was described with the face. 
 
 The calvarium (Fig. 8 1 ) or second covering of the brain has three layers called 
 tables. They are named and distinguished as follows : (i) an outer, tough and 
 resisting ; (2) a middle table which is porous or spongy, called diploe. This is 
 very porous and contains many diploic veins that bleed rather freely during trephin- 
 ing. The characteristic of this table of some of the bones of the cranium is to 
 become absorbed. The intramural sinuses (see p. 1 13), as the frontal, ethmoid, 
 sphenoid, mastoid, may be considered as owing their formation to this process of 
 absorption. (3) The inner or vitreous table is hard and brittle. The inner surface 
 is grooved for the accommodation of the meningeal arteries (Fig. 81), the nutrient 
 arteries to the dura mater and calvarium. 
 
 The meninges form the third or innermost of the three grand protectives of 
 the brain. This covering consists of a dura mater, an arachnoid, and a pia 
 
 GONION 
 
 OB EXTERNAL 
 OCCIPITAL PRO- 
 TUBERANCE 
 
 BASION 
 
 FIG. 81. THE SKULL IN SAGITTAL SECTION. 
 
 mater. The arrangement they bear to each other makes two physiological 
 lymph spaces: (i) a subdural ; (2) a subarachnoid. These terms are self- 
 explanatory, and conform to the rule of subs in the introduction. 
 
 The dura mater is adherent to the bony walls of the calvarium and base of 
 the skull. Its attachments are firmer in those localities where (i) great numbers 
 of nerves are leaving ; (2) where there are numerous foramina ; (3) where there 
 are many sutures. The base of the skull possesses these three characters, hence 
 here the dura is most intimately adhered. 
 
 The dura mater has four double processes, called : (i) Falx cerebri ; (2) falx 
 cerebelli ; (3) tentorium cerebelli ; (4) diaphragma sellse. Each process possesses 
 (i) a free margin; (2) an attached margin; (3) sinuses for the reception of 
 venous blood from the brain. 
 
 The diaphragma sellae is an inconsiderable dural process attached to the 
 margin of the sella turcica, or pituitary fossa, qn the superior surface of the body 
 9 
 
122 
 
 PRACTICAL ANATOMY. 
 
 of the sphenoid bone. In its attached margin is the circular sinus. Under this 
 process of dura is the pituitary body. This body is connected to the tuber 
 cinerium on the floor of the third ventricle of the brain by the infundibulum, 
 which latter passes through an aperture in the diaphragma sellae. 
 
 The falx cerebri (Fig. 82) is between the cerebral hemispheres. It is attached 
 in front to the crista galli of the ethmoid bone ; behind, to the tcntorhnn cerebelli ; 
 above, to the inner surface of the caharium, in the mid-line, and extends from 
 the tentorium to the crista galli. It contains in its attached margin the superior 
 longitudinal sinus; in its free margin its inferior longitudinal sinus. The 
 superior sinus contains the chords Willisii, mechanical devices for strengthening 
 and holding its walls together. Blood in this sinus flows from before backward ; 
 the sinus is fed by veins which open into it from behind forward. 
 
 FOURTH NERVE 
 
 Fall oerebri 
 
 THIRD NERVE 
 
 SECOND NER VE 
 
 Tentorium 
 cerebeUi 
 
 Lateral sinus 
 
 Superior 
 petrusal sinus 
 
 Falx oerebelli 
 
 SEVENTH AND 
 EIGHTH 
 NERVES 
 
 NINTH, TENTH, AND 
 ELEVENTH NER VES 
 
 TWELFTH NER VE 
 
 SECOND CERVICAL NERVE 
 
 Ligamentum denticulatum 
 
 FIFTH 
 NER VE 
 
 FIRST 
 CERVICAL 
 
 NER \ 'E Inferior petrosal sinus 
 
 FIG. 82. THE CRANIUM OPENED TO SHOW THE FALX CEREKRI, THE TENTORIUM CEREBELLI, AI 
 THE PLACES WHERE THE CRANIAL NERVES PIERCE THE DURA MATER. (Sappey.) 
 
 The falx cerebelli is the smallest of the three large dural processes of th( 
 dura. It is between the cerebellar hemispheres. Its attached margin corresponds 
 to the internal occipital crest of the occipital bone. It contains the occipital sinus. 
 
 The tentorium cerebelli is midway, both in location and size, between the 
 two preceding processes. It is between the occipital lobes of the cerebrum and 
 the cerebellum. It protects the latter from the weight of the former. It is attached 
 to the horizontal part of the occipital crucial ridges posteriorly ; anteriorly and 
 laterally, to the superior border of the petrous portion of the temporal bone and 
 to the clinoid processes of the sphenoid bone. In the occipital attachment are 
 found the lateral sinuses ; in the temporal, the superior petrosal sinuses, 
 
 The dura mater has sinuses located as follows (Figs. 82 and 83) : 
 
 1. Superior longitudinal, in the attached margin of the falx cerebri. 
 
 2. Inferior longitudinal, in the free margin of the falx cerebri. 
 
 3. Lateral, in the occipital attached margin of the tentorium cerebelli. 
 
THE HEAD AND NECK. 
 
 123 
 
 4. Superior petrosal, in the petrosal margin of the tentorium cerebelli. 
 
 5. Inferior petrosal, at the inner posterior border of the petrosa. 
 
 6. Occipital, in the attached margin of the falx cerebelli. 
 
 7. Cavernous, external to body of the sphenoid bone. 
 
 8. Circular, in diaphragma sellae, around the pituitary body. 
 
 9. Sigmoid, on the inner part of the mastoid process. 
 
 10. Transverse, connecting the inferior petrosal ; also called basilar. 
 
 1 1. Straight, at junction of falx cerebri and tentorium cerebelli. 
 
 The arteries of the dura mater are the great, small, anterior, and posterior 
 meningeal ; the anterior and posterior ethmoidal ; and branches of the occipital 
 and ascending pharyngeal. The nerves to the dura mater are the sympathetic, 
 ophthalmic, hypoglossal, the pathetic, and the Gasserian ganglion. 
 
 As you have seen in your dissection, the dural sinuses are between the two 
 layers of the dura mater. They are for the reception and transmission of venous 
 
 Falx cerebri 
 
 Choroid plexus 
 Veins of Galen 
 
 Tentorium 
 cerebelli 
 
 Lateral sinus 
 
 CORPUS 
 DENTA TUM 
 
 CA UDA TE 
 
 NUCLEUS 
 LATERAL 
 VENTRICLE 
 
 Superior petrosal 
 
 sinus 
 MASTOID ANTRUM 
 
 Lateral sinus 
 MASTOID PROCESS 
 
 FIG. 83. CORONAL SECTION OF THE HEAD PASSING THROUGH THE MASTOID PROCESS. 
 (From a mounted specimen in the Anatomical Department of Trinity College, Dublin.) 
 
 blood from the brain. The sinuses are lined by endothelial cells, continuous 
 with the lining of the veins. 
 
 The arachnoid membrane you will know by the glistening appearance it 
 gives the brain. Externally it is in relation with the subdural space ; internally 
 with the subarachnoid space. 
 
 Where is the subdural space located and what does it contain / 
 
 It is located between the dura mater and the arachnoid membrane, and con- 
 tains a small amount of fluid. Call this fluid subdural. 
 
 The subaracJmoid space is wJicrc located and contains what / 
 
 It is located between the arachnoid membrane and the pia mater. It contains 
 the greater part of the cerebro-spinal fluid. Call this fluid subarachnoid. 
 
 Docs the subdural fluid communicate with the subarachnoid fluid ? 
 
 No ; the two are separated from each other by the arachnoid membrane. 
 
124 
 
 PR A CTICAL ANA TOM* . 
 
 h tlic pin j f later a/so intact, so as not to permit communication between the sub- 
 arachnoid fluid and the ventricular fluid in the ventricular cavities of the brain ? 
 
 No ; the pia mater has many slits, by which it permits the fluid in the sub- 
 arachnoid space to communicate with other lymph spaces. The main ones are 
 in the pia mater covering the fourth ventricle. They are three in number : Key, 
 Retzius, Magendie. (Fig. 84.) 
 
 The arachnoid is covered externally with endothelial cells. It is joined to 
 the pia by fibrous trabeculae, called the subarachnoid tissue. At the base of the 
 brain it is separated from the pia mater by the anterior and posterior subarach- 
 noid spaces. The anterior is between the temporo-sphenoidal lobes of the 
 cerebrum and in front of the pons Varolii ; the posterior subarachnoid space is 
 between the medulla and cerebellum. These two spaces contain the greater 
 
 HKLU'ATK aUBARACHNOID TIVSfK <'O.\.\Kt"ri.\<; THE Ml\< IIMill, 
 TO THK /'/.I MATKII OVKH Til/:' Cll.\ VKXl TY OP THK HKAIX 
 
 BRAIN 
 
 POSTER f (tit SI' HA KM' II- 
 HO ID SPACE 
 /'O/M.I/A'.V III-' KKY IX THK /'/.I .VATKIt 
 
 n>K.\MK\ 01-' MM1KMHK f\ THK 
 I>IA MATKK 
 
 /'ill. I.I/A'.V <>r KKT/.irs !\ THK 
 !/.( MATER 
 
 FIG. 84. SCHEMATIC. 
 
 To show the location of the foramina of Key and Retzius in the pia mater, whereby the subarachnoid 
 fluid in the subarachnoid space communicates with the fluid in the fourth ventricle. 
 
 part of the subarachnoid fluid. The posterior space communicates with the 
 fourth ventricle of the brain through the pia mater by the foramina of Key and 
 Retzius. (Fig. 84.) 
 
 Where is the cerebro-spinal fluid found and ivliat are its uses t 
 
 The subarachnoid or cerebro-spinal fluid is found in the subarachnoid spaces 
 of the brain and cord and in the ventricular cavities of the brain. Its use is to 
 mechanically protect the nerve centres from shock, and to fill up space, as fat 
 does in some other parts of the body. Its amount is estimated at less than 
 two ounces. The cerebro-spinal fluid of the brain and cord communicate. 
 
 Explain t/ie special features of the subarachnoid space. 
 
 As shown in figure 84, the greater part of the space between the arachnoid 
 membrane and the pia mater is occupied by delicate connective tissue. It is im- 
 
THE HEAD AND NECK. 125 
 
 possible to separate the two membranes whenever this is the case. At the base 
 of the brain you will see some well-defined spaces on removing the brain. 
 
 The Pacchionian glands will be seen as little stubby hairs or even delicate 
 enlargements on the arachnoid membrane, in the neighborhood of the superior 
 longitudinal sinus. They are enlarged villi of this membrane. They often per- 
 forate the dura mater. Occasionally they will be found to perforate the bones 
 of the skull. Their use is not positively known ; but they seem to transmit 
 subarachnoid fluid into the superior longitudinal sinus. 
 
 Of ivliat is the pia mater composed ? 
 
 It is composed of vessels and connective tissue. 
 
 Where is the pia mater found in practical dissection on the cadaver ? 
 
 The pia mater is found : (i) Covering the surface of the brain ; (2) in the 
 interior of the brain, in the third and lateral ventricles, as velum interpositum 
 and choroid plexus ; (3) forming the tela choroidea inferior along the roof of 
 the fourth ventricle. This latter is perforated by three foramina, by which fluid 
 in the ventricles communicates with fluid in the subarachnoid space. (Fig. 84.) 
 
 SUBARA CHNOID SPA CE Superior longitudinal sinus PA CCHIONTA N BODY 
 
 CORPUS CALLOSUM 
 
 FIG. 85. CORONAL SECTION THROUGH THE GREAT LONGITUDINAL FISSURE, SHOWING 
 THE MENINGES. (Key and Retzius.) 
 
 Distinguish between the dura mater surrounding the brain and the dura sur- 
 rounding the spinal cord as follows : 
 
 1. Attachment to bone, firmly and laxly periosteal function. 
 
 2. Dural processes, for supportive purposes. 
 
 3. Dural sinuses, for venous blood. 
 
 4. Pacchionian bodies ; Pacchionian villi. 
 
 These four conditions are found in the cranial dura mater ; the dura of the 
 cord has neither attachments, processes, sinuses, nor Pacchionian bodies. 
 
 To remove a brain take the following steps : If the case is a post-mortem, 
 then it is necessary to conduct your work so as to leave the subject in a present- 
 able form. In this case make (i) an incision from ear to ear through the scalp, 
 turn the front flap down over the face, the back one down onto the neck ; (2) 
 cut through the origin of the temporal muscle, along the complete temporal 
 ridge. Turn this muscle and its heavy fascia down over the zygoma. 
 
 To Mark the Calvarium. Make a line from one-half of an inch above the 
 supraorbital arch on each side, around the head, passing through the external 
 occipital protuberance. Caution : Avoid getting too low in front, lest your incision 
 pass under the roof of the orbit. If you fail to bring your incision to the level 
 
126 PRACTICAL ANATOMY. 
 
 of the external occipital protuberance you will have trouble in removing the cere- 
 bellum. 
 
 To Cut the Calvarium. Saw in the line as indicated in the preceding 
 paragraph. Avoid cutting too deeply in the temporal region. After you have 
 completed the incision with the saw, take a chisel and hammer and test your 
 work. If any places remain uncut, you can easily finish loosening the calvarium 
 with the chisel. The calvarium must be made loose without cutting through the 
 dura mater. Grasp the cut edge of bone above the orbits, and, while an assistant 
 presses down on the chin, pull the calvarium backward ; as it comes off you will 
 hear a noise, produced by the separation of the dura from the bone. On a 
 previous page you have learned that the dura has attachments to the interior of 
 the cranium. 
 
 Now make the following observations : 
 
 1. Note on the inner surface of the calvarium the meningeal grooves for the 
 meningeal arteries. These arteries are between the dura and bone. They furnish 
 blood to both dura and bone. They have nothing to do with the blood-supply 
 to the brain proper. 
 
 2. The Pacchionian bodies and villi (Fig. 82) will be seen on the outer sur- 
 face of the dura mater, in some cases where they have perforated this structure. 
 They produce, by pressure atrophy, the Pacchionian depressions in the inner table 
 of the calvarium. They are a villous product of the arachnoid. Their function 
 is not perfectly understood. They are found in great abundance in the region 
 of the superior longitudinal sinus, and even in the sinus itself. 
 
 3. You will note the great or middle meningeal artery. It consists of 
 several branches, which all spring from one parent stem in the middle fossa of 
 the skull. It lies in the connective tissue that held the dura to the bone. 
 
 4. The superior longitudinal sinus (Figs. 82 and 83) lies in the mid-line. 
 Cut this open from end to end. Take note of the large amount of clotted blood 
 it contains in its posterior half. Make note also of the chordae Willisii in the 
 bottom of the sinus. Clear out the clotted blood, and these cords of Willis will 
 come into view. 
 
 5. The Cerebral Veins. Cut through the dura, with scissors, one inch ex- 
 ternal to the sinus just opened, from before backward, parallel with the sinus. 
 Next make a lateral incision from the first incision to the ear. Do this on both 
 sides. Turn the flaps outward. Turn the. dura up over the median line, and 
 see the veins opening into the sinus from behind forward. 
 
 Origin of the Cerebral Veins. These veins take blood from the part of the 
 brain supplied by the cortical system given off from the circle of Willis. They 
 discharge the blood into the several dural sinuses. 
 
 6. The subdural space is exposed now. It is between the dura and arach- 
 noid. It contains a small amount of fluid for lubrication fluid derived from a 
 source explained in a previous paragraph. This space contains (i) the Pac- 
 chionian bodies ; (2) the veins to the sinuses ; (3) the cranial nerves prior to their 
 emergence. 
 
 7. The falx cerebri (Fig. 82) you will see occupying the great longitudinal 
 tissure between the cerebral hemispheres. Cut its attachment to the crista galli in 
 front, and as you pull it gently backward, cut the remaining veins opening into 
 the sinus. In the free margin of the falx cerebri is the inferior longitudinal 
 sinus. 
 
 8. The arachnoid membrane is the smooth, glistening, transparent structure 
 that you now see covering the brain. It is transparent, for you see the vessels 
 of the pia mater through it. It is smooth on its outer surface, for it is lubricated 
 by the subdural lymph. It is so very delicate you would scarcely suspect its 
 presence. Under it is the subarachnoid space, also containing fluid. 
 
THE HEAD AND NECK. 
 
 127 
 
 9. The Pia Mater. As you have just observed, you can not remove the 
 arachnoid from the pia ; still, you can see perfectly the vessels of the pia mater 
 through the arachnoid. The presence of the subarachnoid tissue prevents 
 separation of these two structures. (Fig. 84.) The pia mater is composed, as 
 you can see on your dissection, of (i) arteries from the circle of Willis, taking 
 blood to the brain ; (2) veins attending these arteries, and finally opening into 
 the dural sinuses ; (3) connective tissue holding these arteries and veins, as the 
 warp of a carpet holds the woof. 
 
 Remember, the individuality of the pia mater depends not on arteries alone, 
 not on veins alone, not on connective tissue alone ; but on all three woven 
 together, the connective tissue being the warp, the vessels the woof. 
 
 Meningeal branch, of 
 anterior ethmoidal artery 
 
 Jfeningfal branch of pos- 
 terior ethmoidal artery 
 
 Middle meningeal 
 
 artery 
 
 OPHTHALMIC 
 
 DIVISION OF 
 
 FIFTH NERVE 
 
 THIRD NER YE 
 
 Cavernous sinus 
 FOl'RTH NERVE 
 AUDITORY AND 
 FACIAL NERVES 
 
 Superior petrosal sinus 
 Inferior petrosal sin-as 
 Petro-sijiiamous sinus 
 SPINAL ACCES- 
 SOR Y NER VE 
 Sigmoid portion of 
 
 lateral sinus 
 Posterior menimjeal 
 bran ch of vertebral 
 artery 
 Left marginal sinus 
 
 Left lateral sinus 
 Superior longitudinal sinus 
 
 Circular sinus 
 Carotid artery 
 SIXTH NERVE 
 Basilar artery 
 Basilar plexus of veins 
 
 Auditory artery 
 Vertebral artery 
 GLOSSO-PHARYNGEAL 
 
 AND PNEUMOGASTRIO 
 Anterior spinal artery [N. 
 HYPOGLOSSAL 
 
 NER VE 
 SPIN A L A CCES- 
 
 SOR Y NER VE 
 
 Right marginal sinus 
 
 cipilal sinus 
 Right lateral sinus 
 
 FIG. 86. THE VENOUS SINUSKS. 
 (From a dissection by W. J. Walsham in St. Bartholomew's Hospital Museum.) 
 
 Structures You See on the Base. Place the cadaver so the head will hang 
 over the end of the table. This position will permit the brain to gravitate to a 
 slight degree out of its bed. Gently shake the brain by rocking the head from 
 side to side. Notice now the following structures : 
 
 1. The frontal lobe of the cerebrum in the anterior fossa. 
 
 2. The olfactory lobe, on the under surface of the frontal lobe. 
 
 3. The optic chiasm and optic nerves. 
 
 4. The internal carotid artery its cerebral stage. 
 
 5. The third cranial nerve motor oculi. 
 
 6. The tentorium cerebelli attached to the petrosa. 
 
 Hints on Dissection of the Foregoing Structures. Gently retract the 
 frontal lobes and you will see the optic nerves covered by their prolongation of 
 
128 PRACTICAL ANATOMY. 
 
 arachnoid. Remove this with one braimvard sweep of the forceps, and expose 
 the optic chiasm. Behind this see the infundibulum, attached above to the brain 
 and below to the pituitary body. See it passing through a hole in the dia- 
 phragma sellae. 
 
 The internal carotid artery will be seen to the outer side of the optic nerve. 
 Do not call this large artery the ophthalmic. Cut the optics behind the chiasm. 
 Cut the internal carotid artery close to the anterior clinoid process. You will 
 now expose the third nerve by breaking the prolongation of arachnoid about it. 
 
 The fourth cranial nerve lies under the free margin of the tentorium. You 
 will see the tentorium attached to the superior border of the petrosa in front. 
 Cut along this border on both sides. Now gently retract the brain. The fourth 
 nerve will pass to the outer side of the posterior clinoid process and disappear 
 under the dura into the cavernous sinus. 
 
 The fifth nerve will now be seen crossing the superior border of the petrosa, 
 near the apex. It also disappears under the dura through the trigeminal 
 notch. 
 
 The sixth nerve will be seen going through the dura one inch below the 
 dorsum sellae. It passes beneath the dura to gain the cavernous sinus with the 
 third and fourth nerves, and the ophthalmic branch of the fifth nerve. 
 
 Find now the seventh or facial nerve, the eighth or auditory nerve, 
 and the auditory artery passing through the internal auditory meatus on the 
 posterior surface of the petrosa. Note the funnel of arachnoid that accompanies 
 these structures to the foramen. The ninth, tenth, and eleventh nerves will 
 now be seen leaving the cranial cavity through the jugular foramen. The 
 twelfth nerve leaves as two twigs : after passing through the dura they unite 
 as one nerve, and leave the skull by the anterior condyloid foramen. 
 
 FORAMINA AT THE BASE OF THE SKULL AND THE STRUCTURES THEY TRANSMIT. 
 
 Foramen Caecum Transmits an emissary vein. 
 
 Nasal Slit Transmits the nasal branch of the ophthalmic 
 
 nerve. 
 
 Olfactory Foramina Twenty in number, transmit the olfactory nerves. 
 
 Optic Foramina, ...... Transmit the optic nerves and the ophthalmic 
 
 artery. 
 
 Sphenoidal Fissure Transmits third, fourth, sixth, and first divisions of 
 
 the fifth nerve, the ophthalmic vein, and sym- 
 pathetic nerves. 
 
 Foramen Rotundum, .... Transmits the second or superior maxillary divi- 
 sion of the fifth nerve. 
 
 Foramen Ovale, ...... Transmits the third division of fifth nerve and 
 
 small meningeal artery. 
 
 Foramen Spinosum, Transmits the great or middle meningeal artery. 
 
 Foramen, Sphenotic Transmits internal carotid and the facial and 
 
 carotid petrosals for Vidian nerve. 
 
 Hiatus Fallopii Transmits petrosal branch of the Vidian nerve. 
 
 Petrosal Foramen Transmits the smaller petrosal nerve. 
 
 Carotid Canal Transmits internal carotid artery and sympathetic 
 
 nerves. 
 
 Internal Auditory Meatus, . . Transmits seventh and eighth nerves and auditory 
 
 artery. 
 
 Jugular Foramen Transmits jugular vein, ninth, tenth, and eleventh 
 
 nerves. 
 
 Anterior Condyloid Foramen, Transmits the hypo-glossal nerve the twelfth 
 
 nerve. 
 
 Foramen Magnum, Transmits (i) spinal cord and its meninges; (2) 
 
 the vertebral arteries and their sympathetic 
 nerves ; (3) the spinal accessory nerve the 
 eleventh nerve. Note the eleventh nerve 
 coming up through the foramen, passing for- 
 ward, and leaving the cranium with the ninth 
 and tenth nerves by the jugular foramen. 
 
THE HEAD AND NECK. 
 
 129 
 
 The Cavernous Sinus. The sinus is located between the apex of the 
 petrous portion of the temporal bone and the sphenoidal fissure. Note that all 
 the nerves you have just seen in the table passing through the sphenoidal 
 fissure also pass through the cavernous sinus. 
 
 The sinus contains the following structures : 
 
 1. The venous blood common to dural sinuses. 
 
 2. The cavernous stage of the internal carotid artery. 
 
 KACH C/M.V/.IA 
 XEIi VE Off ITU 
 KXI'AI'R RE- 
 I'EIVEX A PSU- 
 TEVTIOS III-' 
 MATEH 
 
 FIG. 87. SCHEMATIC. 
 To show the dura mater forming sheaths for the nerves as they leave the cranium. 
 
 3. The sympathetic plexus of nerves on the common carotid artery. 
 
 4. The ophthalmic division of the fifth cranial nerve. 
 
 5. The motor oculi, the third cranial, nerve. 
 
 6. The patheticus, the fourth cranial, nerve. 
 
 7. The abducens, the sixth cranial, nerve. 
 
 Dissection. Remove the dura mater. Take hold of it in the region of the 
 frontal bone, and pull it back. It will come off quite readily. Locate the 
 
 CAVERNOUS SINUS 
 INT.CAROTIO ARTERY - 
 
 Fir,. 88. RELATION OF THE VARIOUS STRUCTURES PASSING THROUGH THE CAVERNOUS SINUS. 
 
 internal carotid artery next to the sphenoid wall of the sinus. The small nerve 
 on the artery is the sixth cranial. You will find the others on the outer wall, 
 from above downward : third, fourth, and fifth. 
 
 The Gasserian Ganglion. Remove in the same way the dura mater from 
 the middle fossa as you did from the anterior, and you will expose the Gasserian 
 ganglion in a depression on the anterior surface of the petrous portion of the 
 temporal bone near the apex. The ganglion lies between two layers of subdural 
 
1 3 o PRACTICAL ANATOMY. 
 
 connective tissue, called Meckel's fascia. The relation of the ganglion to the 
 internal carotid is of great importance in surgical operations on the ganglion. 
 
 In figure 86 the artery will be seen behind the Gasserian ganglion, the third, 
 fourth, sixth, and ophthalmic division of the fifth nerve, and Meckel's fascia. In 
 other words, turn all these nerves aside and you will see the Gasserian ganglion 
 between two layers of subdural connective tissue called Meckel's fascia. The space 
 between these two layers of fascia is called Meckel's space. The space through 
 which the fifth nerve passes, between the tentorium and the superior border of 
 the petrosa, near the apex of the bone, is called the trigeminal notch. Turn the 
 Gasserian ganglion out of its bed and cut through the lower layer of Meckel's 
 fascia, and you will find the internal carotid. In operations for removal of the 
 Gasserian ganglion, this relation of the ganglion to the artery must be borne in 
 mind, since the only protection to the artery is a thin layer of Meckel's fascia. 
 
 Find the superior maxillary division of the fifth nerve leaving by the foramen 
 rotundum in the greater iving of the sphenoid. 
 
 The inferior maxillary division you will find leaving by the foramen ovale in 
 the greater wing of the sphenoid. 
 
 Dissection and study of 
 
 1. The Gasserian ganglion, its branches and relations. 
 
 2. Meckel's fascia, anterior and posterior layers. 
 
 3. The middle, or great, and the other meningeal arteries. 
 
 4. The facial nerve, the seventh cranial in the petrosa. 
 
 5. The tympanic cavity, the tympanum or middle ear. 
 
 6. The petrosal stage of the internal carotid artery. 
 
 7. The cavernous stage of the internal carotid artery. 
 Locate ike following anatomical structures : 
 
 1. The middle meningeal groove and its artery. 
 
 2. The superior border of the petrosa. 
 
 3. The inferior border of the petrosa. 
 
 4. The posterior surface of the petrosa. 
 
 5. The anterior surface of the petrosa. 
 
 6. The internal auditory meatus with the seventh and eighth nerves. 
 
 7. The hiatus Fallopii and great petrosal nerve. 
 
 8. The tegmen tympani or roof of the tympanum. 
 
 9. The foramen lacerum medium. Sphenotic fissure. 
 
 10. The foramen spinosum in the alar spine of sphenoid bone. 
 
 1 1. The sphenoidal fissure in the sphenoid bone. 
 
 12. The foramen ovale for third division of the fifth nerve. 
 
 13. The foramen rotundum for the second division of the fifth nerve. 
 
 14. The anterior, middle, and posterior clinoid processes. 
 Describe the middle meningeal artery. 
 
 It is a branch of the first stage of the internal maxillary artery. External to 
 the cranium it lies behind the internal pterygoid muscle. It passes between the 
 two roots of origin of the auriculo-temporal nerve. It enters the cranium by the 
 foramen spinosum, in the great wing of the sphenoid bone, and ramifies between 
 the dura mater and the bone, both of which it supplies with blood. Its two 
 accompanying veins are tributary to the internal maxillary vein. The middle 
 meningeal artery divides in anterior and posterior branches which supply the 
 greater part of the bones of the cranium. (Fig. 81.) 
 
 This vessel gives off the following minor branches : 
 
 1 . Small branches to the Gasserian ganglion and its adjacent dura mater. 
 
 2. A branch through the hiatus Fallopii to the seventh nerve and tympanum. 
 
 3. Temporal branches perforating the bone to the temporal fossa. 
 
 4. Orbital branches passing through the sphenoid fissure to the orbit. 
 
THE HEAD AND NECK. 131 
 
 From what other sources does tJie dura receive its blood-supply ? 
 
 The anterior meningeal arteries are in the anterior fossa of the skull. They 
 are derived from the ethmoidal branches of the ophthalmic artery, and from the 
 cavernous stage of the internal carotid. The small meningeal is a branch of the 
 first stage of the internal maxillary. It enters the cranium by the foramen ovale 
 with the third division of the fifth nerve. The posterior meningeal arteries 
 come from the vertebral, occipital, and ascending pharyngeal. 
 
 Describe the cavernous stage of the internal carotid artery. 
 
 It is in the cavernous sinus, but covered by the endothelial lining of the sinus. 
 (Fig. 86.) From the inner end of its petrosal stage the artery ascends to the pos- 
 terior clinoid process ; it then lies by the side of the body of the sphenoid, and 
 then gently curves upward between the middle and anterior clinoid processes, and, 
 lastly, curves backward and perforates the roof of the sinus. (Fig. 86.) On the 
 outer side of the artery is the sixth nerve. It is surrounded by sympathetic 
 nerves. 
 
 In this stage the vessel gives off the following branches : 
 
 1. Branches to the walls of the cavernous sinus. 
 
 2. Branches to the Gasserian ganglion. 
 
 3. Anterior meningeal branches to the dura. 
 
 4. Branches to the pituitary body in the sella turcica. 
 Describe the petrosal stage of the internal carotid artery. 
 
 It has in this stage two parts : An ascending part, in front of the tympanum 
 and internal ear ; a horizontal part, which you will see on turning the Gasserian 
 ganglion backward. On the artery you will see numerous sympathetic nerves, 
 the carotid sympathetic plexus, which are ascending branches of the superior 
 cervical ganglion. The carotid, Vidian, and tympanic are its branches. 
 
 WJiat are Mcckel' s fascia, Meckel 's space, Meeker s cave, and the trigcminal 
 notc/i in the literature of the trigeminal nerve ? 
 
 Meckel's fascia is the subdural connective tissue on and under the Gasserian 
 ganglion. Meckel's space is between the two layers of dura, external to the 
 cavernous sinus. Meckel's cave is a depression on the anterior surface of the 
 petrosa for the Gasserian ganglion. The trigeminal notch is an osteological term ; 
 it is a depression in the upper border of the petrosa, near the apex, in which the 
 fifth nerve rests before expansion into the Gasserian ganglion. This notch is 
 converted into the trigeminal foramen by the tentorium cerebelli. 
 
 Describe the Gasserian ganglion. 
 
 This ganglion lies in Meckel's cave, on the anterior surface of the petrosa. 
 It is simply an enlargement on the anterior or sensory root, as it is called, of the 
 fifth cranial nerve. Its posterior relations are the foramen lacerum medium, 
 the great petrosal nerve, and the horizontal part of the petrosal portion of the 
 internal carotid artery. Anterior to it is the dura mater. The ganglion gives 
 off or receives the following branches : 
 
 1 . Filaments from the carotid plexus of the sympathetic. 
 
 2. Nerves to the dura of the middle fossa and tentorium. 
 
 3. The ophthalmic nerve to the orbit and nose. 
 
 4. The superior maxillary nerve to the upper jaw. 
 
 5. The inferior maxillary nerve to the mandibular region. 
 
 Wliat is the function of the ganglion and the branches given off therefrom / 
 It confers the quality of common sensation on all parts to which it is dis- 
 tributed. Behind the ganglion lies a nerve that supplies the muscles of mastica- 
 tion. This is the so-called motor root of the fifth nerve. This nerve has nothing 
 to do with the ganglion. It leaves the base of the skull through the foramen 
 ovale with the inferior maxillary sensory part of the ganglion. (Fig. 53.) 
 
 The tympanum or middle ear may be very satisfactorily dissected by the 
 
132 PRACTICAL ANATOMY. 
 
 student. Its small size is no argument against careful study of its medical and 
 surgical importance, its contents, and its relations, since it is of easy access for 
 dissection, and resolvable into the form of a geometrical cube for purposes of 
 aiding the memory and facilitating a comprehension of the relative position of 
 those anatomical structures that make the middle ear of such great importance. 
 The student should not undertake a dissection of this part until he has a clear- 
 cut idea of the position, relation, and importance of each wall of the cube. If 
 he begins his dissection knowing that the drum of the ear forms the outer wall 
 of the tympanum proper, that the Eustachian tube and mastoid antrum commu- 
 nicate with the tympanum by the anterior and posterior walls respectively, then 
 he will surely find these structures and think of them in relation to the walls of 
 a cube. To say nothing of the part played by the tympanum in hearing, this 
 region is of interest and importance for the following reasons : 
 
 1. The temporo-sphenoidal lobe of the brain lies on its roof. 
 
 2. The floor of the tympanum lies on the jugular fossa. 
 
 3. The drum of the ear and chorda tympani are on the external wall. 
 
 4. The mastoid antrum and cells are behind it. 
 
 5. The internal carotid artery is in front of it. 
 
 6. The facial nerve skirts two sides of it. 
 
 7. The internal ear is in close relation with it. 
 
 8. The drum of the ear may become ruptured. 
 
 9. The interossicular joints may become ankylosed. 
 10. Pus may form in the tympanum. 
 
 Size and Subdivisions of the Tympanum. The tympanum is about one-half 
 of an inch in height and one-sixth of an inch in width. It is prolonged forward 
 as the Eustachian tube and backward as the mastoid antrum, so its length is 
 difficult to determine : for practical purposes one-half of an inch is near enough. 
 The subdivisions are the attic and tympanic cavity proper. The latter is quite 
 narrow, and has the membrani tympani or drum as its outer wall ; the former is 
 broader, contains most of the bones of hearing, and has a part of the temporal 
 bone as its outer wall. Remember, the tympanum is not horizontal, but its 
 anterior end slopes downward, forward, and inward to the Eustachian tube ; its 
 posterior end slopes upward, backward, and outward to the mastoid antrum. 
 
 Study of the tympanum in which this cavity is compared to a box. (Fig. 91.) 
 
 1. The roof of the tympanum is a thin plate of bone, the tegmen tympani, 
 separating the tympanum from the middle fossa at the base of the skull. It is 
 perforated by foramina that transmit the petrosal branches of the seventh nerve. 
 
 2. The floor separates the tympanum from the jugular fossa, in which fossa 
 are the internal jugular vein, and the ninth, tenth, and eleventh cranial nerves. 
 In this floor is an aperture, through which Jacobson's nerve, the tympanic branch 
 of the glosso-pharyngeal, passes to form the tympanic plexus. 
 
 3. The outer wall of the tympanum is formed by the drum below and the 
 squamosa above, these two structures corresponding to the tympanum proper, 
 and the attic respectively. This outer wall is pierced by the following openings : 
 (i) The ifcr clionlie posterius, by which the chorda tympani nerve, a branch of the 
 seventh cranial nerve, enters the tympanum ; (2) the iter chordtc aiiterins, by 
 which the chorda tympani leaves the tympanum ; (3) the (i/aseriau Jissitre, 
 through which pass the tympatiic branch of the internal maxillary artery, the 
 processus gracilis of the malleus, and the laxator tympani muscle. 
 
 4. The inner isall, you will remember, is called the fourth surface of the 
 'petrosa, in Morris' analysis of this part of the temporal bone. This inner wall 
 
 contains: (i) A ridge of bone covering the seventh nerve in its passage 
 through the tympanum, as heretofore explained ; (2) the fenestra ovalis, leading 
 into the vestibule, and to which is attached the base of the stapes, through 
 
 
THE HEAD AND NECK. 133 
 
 the medium of a periosteal membrane ; (3) the promontory, formed by a turn 
 of the cochlea, and covered by the tympanic plexus ; the promontory is below 
 and in front of the fenestra ovalis ; (4) the fenestra rotunda, covered by the 
 membrana secundaria, and communicating with the scala tympani of the 
 cochlea ; (5) the pyramid, from whose summit emerges the tendon of the sta- 
 pedius. A special branch of the seventh nerve pierces the pyramid for the 
 supply of the stapedius muscle. 
 
 5. The posterior ivall commu\\\ca.tQS with the mastoid antrum. As indicated in 
 a previous paragraph, the mastoid antrum is the backward continuation of the 
 upper part of the tympanic cavity, which is called the attic. 
 
 6. The anterior wall of the tympanum presents but one thing for examination 
 the canalis musculo-tubarius. This canal is divided into an upper and a lower 
 compartment by a horizontal lamina of bone, called the processus cochleari- 
 formis. The upper compartment lodges the tensor tympani muscle ; the lower 
 
 FIG. 89. EAR AND TYMPANUM. 
 
 I. Pinna, or auricle. 2. Concha. 3. External auditory canal. 4. Membrana tympani. 5. Incus. 
 6. Malleus. 7. Manubrium mallei. 8. Tensor tympani. 9. Tympanic cavity. 10. Eustachian 
 tube. II. Superior semicircular canal. 12. Posterior semicircular canal. 13. External semi- 
 circular canal. 14. Cochlea. 15. Internal auditory canal. 16. Facial nerve. 17. Large petrosal 
 nerve. 18. Vestibular branch of auditory nerve. 19. Cochlear branch. 
 
 is the osseous part of the Eustachian tube. These structures can be readily seen 
 in dissection. A common broom straw or hairpin may be thrust through the 
 lower part of the canalis musculo-tubarius as a guide. 
 
 Before you attempt to dissect the seventh nerve in its tortuous canal through 
 the petrous portion of the temporal bone, study well the following branches this 
 nerve gives off between the internal auditory meatus and the stylo-mastoid fora- 
 men. In the auditory canal a short communicating branch, rather large and 
 fatty, extends from the seventh to the eighth nerve. This is called the portio 
 inter duram et mollem. The bony canal occupied by the seventh nerve, from the 
 time it leaves the eighth nerve until it emerges from the stylo-mastoid foramen, is 
 called the aqneductus Fallopii, or the facial canal. In this canal the following 
 branches are given off, as you may see by figure 90. 
 
 I. From the geniculate ganglion, the great superficial petrosal nerve ; this 
 passes through the cartilage in the foramen lacerum medium, and is joined by 
 
134 
 
 PRACTICAL ANATOMY. 
 
 some filaments from the carotid sympathetic plexus, called the great deep petro- 
 sal nerve. The union of these two makes a compound nerve called the Vidian 
 nerve. This Vidian, accompanied by vessels of like name, passes through the 
 Vidian canal and joins the ganglion of Meckel, conferring on the same motion 
 and sympathetic qualities. You will recall the fact of osteology that the Vidian 
 canal is at a junctional area formed by the greater ala of the sphenoid bone, its 
 lingula and pterygoid process. Meckel's ganglion derives its sensory root from 
 the spheno-palatine branches of the superior maxillary division of the fifth 
 cranial nerve. 
 
 2. From the geniculate ganglion, the small superficial pctrosal nerve. This 
 nerve receives a communicating branch from the glosso-pharyngeal nerve and 
 leaves the cranium by the canalis innominatus in the sphenoid bone, between the 
 foramen ovale and foramen spinosum, and joins the otic ganglion on the inner 
 surface of the third division of the fifth nerve, near the foramen ovale. 
 
 3. From the geniculate ganglion, the external pctrosal. This nerve joins the 
 
 Supraorbifal 5*.* 
 
 ,ir V-G: ::--; M; 
 
 Q(Uiic Ganij: *' 
 
 FIG. 90. SCHEME OF FACIAL NERVE COMMUNICATING WITH THE FIFTH CRANIAL NERVE. 
 
 sympathetic plexus on the great or middle meningeal artery, near the foramen 
 spinosum. 
 
 4. From the nerve-trunk, below the geniculate ganglion, the tympanic brancli 
 to the stapedius the smallest muscle in the body. This nerve pierces the pyra- 
 mid, on the inner surface of the tympanum. 
 
 5. A branch frcm the carotid sympathetic plexus joins the great superficial 
 pctrosal just outside the cranium, to form the Vidian nerve. 
 
 6. From the main trunk of the nerve (8 in Fig. 90) a branch is given oft", just 
 above the stylo-mastoid foramen, to communicate with the auricular branch 
 of the vagus nerve. 
 
 7. From the main nerve-trunk, just above the stylo-mastoid foramen, the cJwrda 
 tympaui nerve is given off". This nerve passes upward through a bony canal, the 
 iter chordae posterius, to the tympanum. It passes forward under the mucous 
 membrane of the drum of the ear internal to the manubrium of the malleus. The 
 nerve leaves the tympanum by the iter chordae anterius, or canal of Huguier. 
 It communicates with the otic ganglion, passes internal to the external pterygoid 
 
THE HEAD AND NECK. 135 
 
 muscle, and joins the gustatory nerve. It is distributed to the submaxillary and 
 sublingual glands and to the dorsum of the tongue. 
 
 Dissection of the Seventh Nerve in the Petrosa and of the Tympanum. Locate 
 
 the following anatomical structures : 
 
 
 
 1. The superior border of the petrosa. 
 
 2. Anterior and posterior surfaces of the petrosa. 
 
 3. The trigeminal notch near apex of petrosa. 
 
 4. The cave of Meckel on anterior surface of petrosa. 
 
 5. The horizontal part of the carotid canal and its artery. 
 
 6. The great petrosal nerve in the hiatus Fallopii. 
 
 7. The small petrosal nerve in its small canal. 
 
 8. The middle meningeal artery and foramen spinosum. 
 
 9. The tegmen tympani or tympanic roof. 
 
 10. The internal auditory meatus on posterior surface of the petrosa. 
 
 With a small chisel and mallet gently remove the tegmen in such a manner as 
 not to destroy the delicate petrosal nerves on the anterior surface of the petrosa, 
 and then you can look down into the tympanum, or middle ear, the roof now 
 having been removed (tegmen). Now draw a line from the internal auditory 
 meatus to where the great petrosal nerve is seen emerging. This line will locate 
 the course of the seventh nerve in its canal to the tympanum. Now begin at the 
 internal end of the line just drawn and chip off the bone until you have completely 
 exposed the seventh nerve to the tympanum, where you will see the geniculate 
 ganglion giving off petrosal nerves. 
 
 The tympanum may be represented as a box with an inner and an outer 
 wall, a roof and a floor, an anterior and a posterior end. The seventh nerve 
 approaches the tympanum, at a point corresponding to the junction between 
 the roof and inner wall, near the front end of the box. The seventh nerve 
 having gained this point, now passes backward in the angle between the roof 
 and inner wall to the corner of the box between the inner wall and posterior 
 end of the box. The nerve here makes a gentle turn and passes down this cor- 
 ner to the floor of the box, and subsequently emerges from the base of the skull 
 through the stylo-mastoid foramen. You may see the geniculate ganglion of the 
 nerve just where the nerve is making the bend to enter the tympanum. Now 
 locate the nerves as described previously, and consult figure 90. 
 
 BLOOD-SUPPLY TO THE BRAIN. 
 
 Examine the base of the brain. You notice very distinctly the arachnoid 
 membrane quite appreciably separate from the pia. In other words, here you 
 see the subarachnoid space. Now remove carefully the arachnoid and dissect 
 the circle of Willis. You will note the following : 
 
 1 . The vertebral arteries unite to form the basilar artery. 
 
 2. The basilar divides into the two posterior cerebral arteries. 
 
 3. The internal carotid artery gives off three large arteries (Fig. 91) : 
 (i) The anterior cerebral, in the great longitudinal fissure ; (2) the middle cerebral, 
 in the fissure of Sylvius on the central lobe ; (3) the posterior communicating, to 
 the posterior cerebral. 
 
 The arachnoid membrane, it will be observed, stretches across from frontal 
 to temporo-sphenoidal lobe, so as almost to obscure the fissure of Sylvius. Cut 
 this membrane with the scissors, gently part the lobes, and you will see the 
 island of Reil, on which is the middle cerebral artery with its vein. 
 
 The anterior communicating artery is very short, one-eighth of an inch 
 being an average length in a number of cases. You will find it extending from 
 one anterior cerebral artery to the other. 
 
i 3 6 
 
 PR A CTICAL ANA TO. M J . 
 
 The ganglionic or terminal end arteries will be seen in very great numbers 
 on lifting the middle, posterior, and anterior cerebral arteries. They are very 
 minute. Look closely, and you will see them passing through minute perfora- 
 tions to the interior of the brain through the perforated spaces. (Fig. 92.) 
 
 The interpeduncular space has (i) boundaries; (2) contents. The con- 
 tents form the floor of the third ventricle. The boundaries are important 
 structures on the base of the brain which I wish you to study carefully. 
 (Fig. 92.) 
 
 The Boundaries of the Interpeduncular Space. (i) Antero-laterally, optic 
 chiasm and optic tracts ; (2) postero-laterally , pons Varolii and crura cerebri. 
 
 Contents of Interpeduncular Space. (i) The tuber cinereum ; (2) infundibulum, 
 pituitary body ; (3) the corpora albicantia, part of the fornix ; (4) posterior 
 
 Anterior cerebral 
 artery 
 
 Middle cerebral 
 
 artery 
 Internal carotid 
 
 artery 
 Poslero-median 
 
 perforating 
 Posterior cerebral 
 
 artery 
 
 Superior cerebellar 
 artery 
 
 Anterior inferior 
 ccrebellar artery 
 
 Vertebral artery 
 
 Posterior inferior 
 cerebellar artery 
 
 A nterior com- 
 municating 
 artery 
 
 Antero-lateral 
 perforating 
 
 A nttrior clioroid 
 
 Posterior 
 communicating 
 artery 
 
 Posterior choroid 
 
 Basilar artery 
 Cfnis cerebelli, cut 
 
 Anterior spinal 
 artery 
 
 FIG. 91. THE ARTERIES OF THE BRAIN. 
 (From a preparation in the Museum of St. Bartholomew's Hospital.) 
 
 perforate space, for terminal end arteries ; (5) the third cranial nerve, mot 
 oculi nerve. 
 
 Notice in particular : 
 
 1. The optic tracts crossing the crura cerebri. 
 
 2. The third nerve, motor oculi, between the crura cerebri. 
 
 3. The terminal end arteries from the circle of Willis. (Fig. 91.) 
 
 4. The basilar artery on the body of the pons Varolii. (Fig. 91.) 
 
 5. The fourth nerve, coming out between the pons and crus cerebri. 
 
 6. The fifth nerve, coming from the side of the pons Varolii. 
 
 7. The sixth nerve, coming through between the pons and medulla. 
 
 8. The seventh and eighth nerves, between the olivary and restiform bodies. 
 
 9. The ninth, tenth, and eleventh nerves, between the olivary and restiform 
 bodies. 
 
 10. The twelfth nerve, between the pyramid and olive. 
 
THE HEAD AND NECK. 
 
 '37 
 
 Two systems of circulation are given off from the circle of Willis: (i) 
 Tlic ganglionic ; (2) tlie cortical. You have just seen the ganglionic or end 
 arteries entering the brain by the perforated spaces. The cortical arteries and 
 their veins form the woof of the pia mater, the warp of which is connective tissue. 
 
 i . From what source docs the brain receive its blood ? 
 The brain is supplied with blood by the circle of Willis. 
 
 OPTIC THALAMUS 
 
 OPTIC TRACT 
 TUBER CINEREUM 
 
 POSTERIOR PER- 
 FORATED SPACE 
 
 CORPUS GENICU- 
 LA TUM EXTKRNUM 
 
 CORPUS GENICU- 
 LA TUM INTERNUM 
 
 PYRAMIDAL BODY 
 OLIVARY BODY 
 
 ARCIFORM FIBRES 
 
 ISLAND OF REIL 
 PITUITARY BODY 
 
 CORPORA 
 ALBICANTIA 
 
 CRUS CEREBRI 
 
 PONS VAROLII 
 
 GREA T HORIZONTA L 
 
 FISSURE 
 FLOCCULUS 
 
 FORAMEN CAECUM 
 
 SPIN A L A CCESSOR Y 
 NERVE 
 
 FIRST CER VICAL NER VE 
 
 ANTERO-LATERAL GROOVE 
 
 OF SPINAL CORD 
 ANTERIOR COLUMN OF 
 SPINAL CORD 
 
 FIG. 92. SURFACE ORIGIN OF THE CRANIAL NERVES. (After Allen Thomson. Quain.) 
 
 2. How is this circle formed ? 
 
 It is formed by an anastomosis between branches of the internal carotid and 
 vertebral arteries. 
 
 3 . How does the internal carotid reach the brain ? 
 
 It comes through the carotid canal and sphenotic foramen, and gives off: (i) 
 The anterior cerebral ; (2) the middle cerebral ; (3) the posterior communi- 
 cating. 
 
 4. Hoiv docs the vertebral artery reach tJie brain ? 
 
 It passes through the foramina in the transverse processes of the cervical 
 vertebrae and the foramen magnum. It divides into the two posterior cerebral 
 arteries. 
 
 5 . How is the blood returned from the brain / 
 
 The blood from the ganglionic system is returned to the straight sinus by 
 
138 PRACTICAL ANATOMY. 
 
 the veins of Galen. (Fig. 82.) The blood from the cortical system is returned 
 by various veins to the several dural sinuses. 
 
 6. What becomes of the blood in the sinuses / 
 
 The sinuses converge to form the internal jugular vein. This vein is made 
 up at the jugular foramen, and leaves it in company with the ninth, tenth, and 
 eleventh cranial nerves. 
 
 7. Do the branches given off from the ganglia nic system communicate until one 
 another or with branches of the cortical system ? 
 
 No. 
 
 8. Where do the branches forming the ganglionic system take their origin, and 
 hoiv are they named? 
 
 They originate from the circle of Willis and from its primary branches for an 
 inch beyond the circle. They are named : 
 
 Antero-median, from the anterior communicating artery. 
 Antero-lateral, from the middle cerebral artery. 
 Postero-median, from the posterior cerebral artery. 
 Postero-lateral, from the posterior cerebral artery. 
 
 9. What is the most important function of this system of circulation / 
 
 To supply blood to the basal ganglia, the most important part of the 
 brain. 
 
 10. Name the most important branch of the ganglionic system, and give its 
 surgical importance. 
 
 The lenticulo-striate artery. It is the largest, and most frequently the seat 
 of embolism or hemorrhage. It passes through the internal capsule. 
 
 1 1 . Do all the branches of the ganglionic system supply basal ganglia / 
 
 No ; the anterior and posterior choroid branches supply the choroid plexuses 
 of the lateral ventricles and some minor adjacent parts. 
 
 1 2. Has any part of the ganglionic system anything to do with the formation 
 of the pia mater ? 
 
 As mentioned in a previous paragraph, the anterior and posterior choroid 
 arteries are branches of the ganglionic system, but they do not supply basal 
 ganglia ; they supply the choroid plexuses, in the lateral ventricles, and these 
 plexuses, with the velum interpositum, are extensions from the general pia 
 mater on the surface of the brain to equally superficial parts of the brain, 
 apparently, but not really, on the interior of the brain. 
 
 13. Arc the terms pia mater and cortical system of circulation, for practical 
 purposes, synonymous / 
 
 Yes ; the pia mater consists of vessels, arteries and veins, and connective 
 tissue ; the arteries, for the most part, originate beyond the confines of the gang- 
 lionic system. The pia mater is applied to every part of the outer surface of the 
 brain ; it reaches into the fissures and sulci. It forms the velum interpositum 
 and the choroid plexuses. 
 
 1 4. How are the cerebral veins classified / 
 
 They may be grouped as ganglionic, basilar, and cortical, (i) The central 
 or ganglionic veins come together to form the veins of Galen, having gathered 
 in their course the veins of the choroid plexuses and velum interpositum. 
 The veins of Galen, from the two hemispheres, unite to form the common vein 
 of Galen, a trunk about one-half of an inch in length ; this, as seen previously, 
 opens into the straight sinus. (2) The basilar veins collect the blood from the 
 under surface of the cerebrum, and feed the petrosal, cavernous, and lateral 
 sinuses. (3) The cortical veins gather the blood from the outer and inner 
 surfaces of the hemispheres and feed the superior and inferior longitudinal 
 sinuses in the attached and free margins of the falx cerebri respectively. 
 
 
THE HEAD AND NECK. 139 
 
 Find the following fissures and their contents : 
 
 1. Tlie great longitudinal fissure contains : (i) The falx cerebri with its 
 superior and inferior longitudinal sinuses ; (2) the corpus callosum, on which 
 you may see the anastomosis between the anterior and posterior cerebral 
 arteries. 
 
 2. The great transverse fissure, between the occipital cerebral lobes and the 
 cerebellum. It contains the tentorium cerebelli. 
 
 3. The fissure of Sylvius, bounded below by the temporo-sphenoidal lobe; 
 above by the frontal and parietal lobes. It contains : (i) The island of Reil, or 
 central lobe of the cerebrum ; (2) the middle cerebral artery and vein and their 
 numerous branches. 
 
 4. The fissure of Rolando is between the ascending convolutions of the frontal 
 and parietal lobes. Its surgical importance is due to the fact of the location of 
 the cortical motor areas about this fissure. 
 
 5. The occipito-parietal fissure is very imperfect. As its name implies, it is 
 between the parietal and occipital lobes. 
 
 Dissection of the brain does not belong to dissecting-room anatomy, hence 
 the reader is referred to Morris for this very interesting and instructive part of 
 anatomy. 
 
 THE ORBIT AND ITS CONTENTS. 
 
 For dissecting-room purposes, the following points seem of practical or 
 rather demonstrable importance : 
 
 i. Geometry of the Orbit. Roof, floor, outer wall, inner wall, base, apex, 
 angles, and cavity. 
 
 The roofis of importance, since it separates the cavity of the orbit from the 
 frontal lobes of the brain. A missile may reach the brain in this way, since this 
 roof is often very thin. 
 
 The floor is of importance (i) because it forms a partition between the orbit 
 and the antrum of Highmore, or maxillary sinus ; (2) because it is traversed by 
 the infraorbital canal, in which are the infraorbital nerve and vessels. 
 
 The inner wall is in close relation with the nasal fossae, and the ethmoid cells, 
 the os planum of the ethmoid, and the lachrymal bones form a large part of the 
 partition between these cavities. 
 
 The outer wall is formed by the orbital plates of the sphenoid and malar 
 bones, but is of no special importance. 
 
 The apex of the orbit transmits the optic nerve and the ophthalmic branch 
 of the internal carotid artery. The apex is occupied by the optic foramen, be- 
 tween the two pedicles of the lesser ala of the sphenoid bone. 
 
 The base of the orbit is of great importance on account (i) of its architectural 
 construction, combining beauty, strength, and protection ; (2) of the large num- 
 ber of anatomical structures in this region. 
 
 Note about the base of the orbit : 
 
 1. The laclirymal gland (Fig. 104), under the external angular process of 
 the frontal bone, in a fossa called the lachrymal fossa. This is called the orbital 
 part of the gland or the superior lachrymal gland ; the part of the gland that 
 protrudes below this is called the palpebral portion or the inferior lachrymal 
 gland. 
 
 2. The S2ipraorbital foramen (it may be double) transmits the supraorbital 
 nerve and vessels. (Figs. 98, 103.) The vessels are branches of the ophthalmic. 
 
140 
 
 PRACTICAL ANATOMY. 
 
 The nerve is a branch of the frontal part of the ophthalmic, itself a branch of 
 the fifth cranial nerve. 
 
 3. The trochlea is found on the inner wall, near the base of the orbit. 
 Around this trochlea plays the tendon of the superior oblique muscle of the 
 eyeball. (Fig. 100.) Here, too, occurs the anastomosis between the supra- 
 trochlear branch of the frontal and the infratrochlear branch of the nasal nerve. 
 
 The nasal duct has its beginning in the internal inferior angle of the orbital 
 base. (Fig. 104.) By this duct excessive tears reach the nasal fossae. 
 
 PALPEBRAL FISSURE 
 INNER CANTHUS 
 
 OUTER CANTHUS 
 
 TENDO OCULI DELAMINATES INTO SUPERIOR AND 
 INFERIOR PALPEBRAL RAMI 
 
 Tendo oouli or internal tarsal 
 ligament 
 
 INFERIOR TARSAL LIGAMENT 
 
 FIG. 93. TENDO OCULI AND TARSAL CARTILAGES. 
 
 The infraorbital nerve (Fig. 51), emerges from the orbit by the infraorbital 
 foramen just below the base of the orbit. This sends off anterior superior 
 branches to the teeth just prior to its emergence. 
 
 The tendo oculi crosses the lachrymal sac in front (Fig. 94), giving off an 
 aponeurosis to the same. Observe the caruncula lachrymalis between the t\vo 
 diverging rami of the tendo oculi. 
 
 The tendo oculi, or internal tarsal ligament, has its origin from the nasal 
 process of the superior maxilla. (Fig. 10.) The superior and inferior tarsal 
 
 1 1 15J 
 
 FIG. 94. RELATIONS OF THE EYE AND THE LACHRYMAL EXCRETORY APPARATUS. 
 I, I. Canalicirii. 2, 2. Puncta lachrymalia. 3, 3. Inner extremity of tarsal cartilage. 4, 4. Free 
 borders of lids. 5. Lachrymal sac. 6. Attachment to maxillary bone of superior tendon. 7. Bifur- 
 cation of lachrymal sac. 8, 8. Two branches. 
 
 ligaments, of periosteal derivation (Fig. 21), are attached to the margin of the 
 base of the orbit both above and below. The external tarsal ligament is not 
 divided. 
 
 The Angles of the Orbit. 
 
 1 . The superior internal. This contains the anterior and posterior etJnnoidal 
 foramina. The former transmits the anterior ethmoidal artery and nasal nerve ; 
 the latter, the posterior ethmoidal artery. 
 
 2. The superior external angle. This contains in front the lachrymal fossa 
 already described, and posteriorly the sphcnoichil fissure. This fissure transmits 
 
THE HEAD AND NECK. 
 
 141 
 
 the third, fourth, sixth, and the three divisions of the ophthalmic branch of the 
 fifth nerve, the ophthalmic vein, and some minor structures. 
 
 3. The inferior external angle. In this is the spheno-maxillary fissure. This 
 fissure transmits the superior maxillary nerve and its orbital branches, the ascend- 
 ing branches from Meckel's ganglion, the infraorbital branch of the internal max- 
 illary artery and its vein. 
 
 4. The inferior internal angle contains the beginning of the osseous part of 
 the lachrymal apparatus that conveys tears to the nasal fossae. This apparatus 
 will be considered under the head of orbital contents. (Fig. 104.) 
 
 The periosteum of the orbit (Fig. 95) lines the walls of the cavity, 
 delaminates at the orbital margin of the base, one layer uniting with the peri- 
 osteum externally, the other layer forming the tarsal ligaments and tarsal 
 cartilages above and below. The orbital fascia is to the contents of the orbit, 
 other things equal, what the deep fascia of the thigh is to the structures of the 
 thigh. Keep this in mind, for here, as in the thigh, you will find sheaths, 
 capsules, and septa derived from this fascia. 
 
 In your dissection you will find the following structures 
 
 1. The optic nerve the special nerve of the sense of sight. (Fig. 100.) 
 
 2. The motor oculi nerve, or third nerve. (Fig. 98.) 
 
 OPTIC FORAMEN 
 
 DELAMINATION OF THE ORBITAL 
 PERIOSTEUM 
 
 arsal ligament 
 
 Tarsal cartilage 
 
 PALPEBRAL FISSURE 
 
 ORBITAL PERIOSTEUM 
 
 OHBITAL PERIOSTEUM 
 
 FIG. 95. SCHEMATIC REPRESENTATION TO Snow RELATION OF PERIOSTEUM TO TARSAL CARTI- 
 LAGES AND TARSAL LIGAMENTS. 
 
 3. The patheticus, or fourth nerve. (Fig. 98.) 
 
 4. The abducens, or sixth nerve. (Fig. 98.) 
 
 5. Ophthalmic branch of the fifth nerve. (Fig. 98.) 
 
 6. The lachrymal gland and its capsule. (Fig. 103.) 
 
 7. The ophthalmic artery and its branches. (Fig. 103.) 
 
 8. The ophthalmic vein and its branches. (Fig. 103.) 
 
 9. The ciliary ganglion and its branches. (Fig. 98.) 
 
 10. The orbital connective tissue and fat. 
 
 11. The levator palpebrae muscle. (Fig. 100.) 
 
 12. The superior rectus muscle. (Fig. 100.) 
 
 13. The external rectus muscle. (Fig. 99.) 
 
 14. The inferior rectus muscle. (Fig. 99.) 
 
 15. The internal rectus muscle. (Fig. 99.) 
 
 1 6. The superior oblique muscle. (Fig. 100.) 
 
 17. The inferior oblique muscle. (Fig. 100.) 
 
 1 8. The capsule of Tenon. 
 
 19. The eyeball with sclerotica and iris. (Fig. 99.) 
 Dissection of the Orbital Contents Steps : 
 
 I. Remove the orbital plate and supraorbital arch by cutting through the 
 
142 
 
 PRACTICAL ANATOMY. 
 
 internal and external angular processes of the frontal bone. (Fig. 96.) Carefully 
 remove the bone without injuring the periosteum of the orbit. 
 
 2. Cut through the orbital periosteum and find, immediately under the peri- 
 osteum, the frontal nerve. The frontal nerve lies on the levator palpebrae with the 
 supraorbital artery and vein. It is a branch of the ophthalmic part of the fifth 
 
 Internal rectus muscle 
 
 Superior oblique muscle 
 
 Trochlea 
 
 Levator palpebrse superioris 
 muscle, cut 
 
 External rectus muscle 
 
 Inferior oblique muscle 
 Superior rectus muscle 
 
 Levator palpebrae superior-is 
 muscle, cut 
 
 FIG. 96. VIEW OF LEFT ORBIT FROM ABOVE, SHOWING THE OCULAR MUSCLES 
 (From Hirschfeld and Leveille. ) 
 
 FIG. 97. MUSCLES OF THE EYE. 
 I. Tendon of Zinn. 2. External rectus divided. 3. Internal rectus. 4. Inferior rectus. 5- Superior 
 rectus. 6. Superior oblique. 7. Pulley for superior oblique. 8. Inferior oblique. 9. Levator 
 palpebne superioris. 10, 10. Its anterior expansion. II. Optic nerve. 
 
 nerve. You will see it divide into two branches: (i) the supratrochlear and 
 (2) the supraorbital. The supratrochlear inosculates with the infratrochlear 
 branch of the nasal nerve. The supraorbital comes through the supraorbital 
 foramen, and is distributed to the forehead and inner part of the upper eyelid. 
 
 The levator palpebrae superioris muscle (Fig. 97) lies under the preceding 
 frontal nerve. It is inserted into the tarsal ligament of the upper lid. It lies orv 
 
THE HEAD AND NECK. 
 
 143 
 
 the superior rectus muscle. Cut the muscle in the middle, turn the ends out of 
 the way, and expose the superior rectus muscle. (Fig. 96.) 
 
 The Superior Rectus Muscle (Fig. 96). This muscle lies under the levator 
 palpebrae. It is inserted into the sclerotic coat of the eyeball. Cut it, and 
 turn the ends aside. You will see under this muscle a bed of fat. In the 
 centre of the bed of fat and connective tissue is the optic nerve. (Fig. 103.) 
 
 The Optic Nerve. To the outer side of this nerve you will see the external 
 rectus muscle. Between the nerve and this muscle you will see the ciliary ganglion. 
 
 Study the ciliary ganglion according to this outline (Fig. 98) : 
 
 1. Location between the optic nerve and external rectus muscle. 
 
 2. Size, about as large as a pin's head, but spider-like. 
 
 3. Roots : (i) A motor, from the branch of the third nerve to the inferior 
 oblique; (2) a sensory, from the nasal nerve; (3) a sympathetic, from the 
 cavernous plexus. 
 
 4. Distribution and function. Branches are given off from this ganglion, 
 called the short ciliary nerves. They go with the optic nerve surrounding the 
 
 LENTICULAR GANGLION 
 SUPERIOR DIVISION OF THE THIRD NERVE 
 
 NASAL H RANCH OF OPHTHALMIC 
 
 SUPRAORKITAL 
 NER VE 
 
 SHORT CILIARY 
 NER VES 
 
 BRANCH OF THIRD TO 
 INFER [OR OBLIQUE 
 
 LONG ROOT OF LENTICU- 
 LAR GANGLION 
 
 4 
 
 OPTIC NER VE 
 
 THIRD NERVE 
 SIXTH NERVE 
 GASSERIAN GANGLION 
 
 OPHTHALMIC DIVISION 
 OF FIFTH NERVE 
 
 SHORT ROOT OF SYMPA THETIC ROOT OF LENTICULAR 
 
 LENTICULAR GANGLION GANGLION 
 
 FIG. 98. NERVES OF THE ORBIT, FROM THE OUTER SIDE. 
 (From Sappey, after Hirschfeld and Leveille.) 
 
 same. On piercing the sclerotic coat they are joined by the long ciliary 
 branches from the nasal nerve. (Fig. 98.) These branches are distributed to 
 the iris and ciliary muscle. 
 
 From wliat source does the ciliary ganglion derive its sympathetic influence, and 
 hoi*.' docs the same enter the orbit ? 
 
 It derives it from the superior cervical ganglion. The ascending fibres enter 
 the cranium on the internal carotid artery. Here some fibres accompany the 
 branches of this artery to the brain. Other fibres leave the artery in its cavern- 
 ous stage, pass through the sphenoidal fissure to the orbit, and supply the ciliary 
 or lenticular ganglion. 
 
 Give the influence of paralysis of tlie third nerve on t/ie iris. 
 
 Since the iris derives its motor influence, through the ciliary ganglion, from 
 the third nerve, loss of power of contraction of the pupil would follow. 
 
 The Optic nerve, you will find, is surrounded by very small nerves and 
 arteries. (Figs. 98 and 103.) The nerves are: (i) Short ciliary, from the 
 ciliary ganglion ; (2) long ciliary, from the nasal nerve. The arteries are ciliary, 
 derived from the ophthalmic or some of its branches. The optic nerve derives 
 its sheath from the dura mater. 
 
144 
 
 PRACTICAL ANATOMY. 
 
 The external rectus muscle lies to the outer side of the optic nerve. It is 
 attended by the lachrymal nerve, a branch of the ophthalmic nerve, and the 
 lachrymal artery, a branch of the ophthalmic artery. You will dissect the 
 three together and associate them in your memory. The lachrymal structures 
 are on their way to the lachrymal gland. Turn the external rectus muscle 
 
 Tendon of superior oblique 
 
 Trochlea 
 
 Internal reotue 
 
 Inferior oblique muscle 
 
 Levator palpebrae super- 
 
 ioris, cut 
 Superior rectus 
 
 External rectus 
 
 Inferior rectu* 
 
 FIG. 99. LEFT EYEBALL SEEN IN ITS NORMAL POSITION IN THE ORBIT, WITH VIEW OF THE 
 OCULAR MUSCLES. (After Merkel, modified.) 
 
 FIG. loo. MUSCLES OF ini. \-.\\-.. TENDON OR LK;AMKM OF /INN. 
 I. Tendon of Zinn. 2. External rectus divided. 3. Internal rectus. 4. Inferior rectus. 5. Superior 
 rectus. 6. Superior oblique. 7. Pulley for superior oblique. 8. Inferior oblique. 9. Levator 
 palpebrse superioris. 10, 10. Its anterior expansion. II. Optic nerve. 
 
 outward, and on its inner surface you will see the fine filaments of the sixth 
 cranial nerve the abducens. 
 
 The Superior Oblique Muscle and the Fourth Nerve (Fig. 97). These 
 form a group by themselves. You will trace the tendon of this muscle around 
 the trochlea, where it turns at a right angle and passes outward under the 
 
THE HEAD AND NECK. 145 
 
 superior rectus to be inserted into the sclerotica. You will find its nerve, the fourth, 
 breaking up into a number of filaments on the ocular surface of the muscle. 
 
 The nasal nerve crosses the optic nerve, passes under the superior rectus 
 muscle, then passes between the superior oblique muscle and the internal oblique 
 muscle. Here it gives off its infratrochlear branch to meet the supratrochlear 
 branch of the frontal nerve. These two are sensory nerves. The nerve leaves 
 the orbit by the anterior ethmoid foramen with the anterior ethmoidal artery. In 
 the cranial cavity it lies under the dura, on the cribriform plate of the ethmoid 
 bone. It passes through the nasal slit to the nasal fossae. In the nasal fossae it 
 
 Superior reetus 
 FOURTH NERVE \ 
 
 Lsvator palpsbree superioris 
 
 Lachrymal and frontal vein __SjM|K (#^lL f^~ Su P erior oblique 
 
 . d f ge e ovfA a P hen C oi U d 8 al fr fls n sur i e brOU8 ~ T^S*1^~ PT1C F RA ^'^ A * D * Eli ' ' E 
 Naso-ciliary of fifth nerve jlS*$_^ ~ Internal rectus 
 
 SIXTH NERVED / \ 
 
 ' N Inferior reetus 
 
 External reotus THIRD NER VE 
 
 FIG. 101. DIAGRAMMATIC REPRESENTATION OF ORIGINS OF OCULAR MUSCLES AT THE APEX 
 
 OF THE RIGHT ORBIT. 
 (After Schwalbe, slightly altered.) 
 
 divides into branches : (i) Septal, to the mucous membrane of the septum ; (2) 
 turbinals, to the turbinated bones. A small twig from the latter passes between 
 the lower end of the nasal bone and its cartilage, and appears on the face as the 
 naso-lobular a nerve of sensation, of course, to the wing and tip of the nose. 
 
 TABLE OF ORIGIN OF OCULAR MUSCLES. 
 NAME. ORIGIN. 
 
 Levator palpebrae superioris, . Above optic foramen from lesser ala of sphenoid. 
 
 Superior rectus, Upper margin of optic foramen. 
 
 Inferior rectus, From ligament of Zinn. 
 
 Internal rectus, From ligament of Zinn. 
 
 External rectus, Upper head. Outer margin of optic foramen. 
 
 External rectus, Lower head. From ligament of Zinn. 
 
 Superior oblique, Above the optic foramen. 
 
 Inferior oblique, Orbital plate of superior maxilla. 
 
 The internal rectus and the inferior rectus may be brought into view by 
 cutting the optic nerve and pushing the eyeball and the fatty mass forward. 
 You will see these muscles taking their nerve-supply from the third nerve. 
 Trace each muscle to its insertion into the sclerotica. 
 
 The inferior oblique muscle arises from the orbital plate of the superior 
 maxilla just external to the lower end of the lachrymal groove. It is inserted 
 into the sclerotica, on the outer surface, in such a way as to antagonize the 
 superior oblique muscle. Its nerve, the long branch of the third cranial, is of 
 large size, and gives to. the ciliary ganglion its motor root. 
 
 The orbital fascia invests the muscles. It passes forward on the tendons. 
 In the vicinity of the globe it binds the tendons together by extending from one 
 to another, thus forming, posterior to the ball, a loose double capsule the 
 capsule of Tenon. This double layer forms a socket for the ball to move in. It 
 separates posteriorly the fatty contents of the orbit from the globe of the eye. 
 
 Describe the Ophthalmic Artery (Fig. 103). It is a branch of the inter- 
 nal carotid artery. It enters the orbit by the optic foramen with the optic nerve. 
 It is attended by the ophthalmic vein, which leaves the orbit by the sphenoidal 
 
146 
 
 SKIN OF LOWER LID 
 LOWER TARSUS 
 Palpebral fascia and 
 aat. lamina of muscle- 
 fascia 
 
 Orbicularis palpe- 
 
 brarum 
 
 Intension of sheath of 
 inferior root us to 
 lower eyelid 
 
 FORNIX CONJUNCTIV/C 
 
 Inferior oblique mu3ol3, 
 cut across 
 
 PERIORBITA 
 
 Posterior lamina of 
 muscle-fascia 
 
 SUPRAVAGINAL SPACE CONTINUOUS 
 
 WITH TENON'S SPACE 
 SPACE OCCUPIED BY ORBITAL FAT, PRO- 
 CESSES OF FASCIA SEPARATING THE 
 LOBULES AND ENCLOSING BLOOD- 
 VESSELS 
 
 Inferior rectus 
 
 PR A CTICAL ANA TO MY. 
 \ 
 
 SKIN OF UPPER LID 
 UPPER TARSUS 
 CORNEA 
 
 Orbicularis palpe- 
 
 brarum 
 
 UPPER RIM OF ORBIT, WITH 
 Splitting of periorbita 
 Upper or anterior insertion 
 
 of levator palpebrae 
 Superior palpebral muscle of 
 FORNIX CONJUNCTIV/E [Miiller 
 
 Connection between levator 
 palpebrae and sup. reetus, 
 and fibres to conjunctiva 
 
 PROCESS FROM PERIORBITA TO 
 CAPSULE OF LACHRYMAL GLAND 
 
 Superior rectus 
 
 Levator palpebrae 
 superioris 
 
 Posterior lamina of muscle- 
 fascia lined by prolongation of 
 Tenon's capsule 
 
 OPTIC NERVE 
 
 FIG. 102. VERTICAL SECTION THROUGH THE EYEBALL AND ORBIT IN THE DIRECTION OF THE 
 
 ORBITAL Axis, WITH CLOSED EYELIDS. 
 
 (Semi-diagrammatic. After Schwalbe, modified to show fasciae.) 
 Periorbita green ; muscle-fascia red; Tenon's capsule yellviv. 
 
 Snpraorbital artery 
 
 LACHRYMAL GLAND 
 
 Superior rectus, cut 
 
 EYEBALL 
 
 External rectus 
 Lachrymal artery 
 
 Superior rectus, out 
 Inferior ophthalmic vein 
 Superior ophthalmic vein 
 
 OPTIC NKR VI-: 
 Common ophthalmic vein 
 
 Commencement o/ superior 
 ophthalmic vein 
 
 Reflected tendon of superior 
 
 oblique 
 Ophthalmic artery 
 
 Anterior ethmoidal artery 
 
 Posterior ethmoidal artery 
 Ciliary arteries 
 
 Levator palpebrae, cut 
 Ligament of Zinn 
 iiilmic artery 
 
 OPTIC COMMISSURE 
 
 Internal carotid artery 
 
 FIG. 103. TIIK OPHTHALMIC ARTKKV AND VEIN. 
 
THE HEAD AND NECK. 147 
 
 fissure and expands behind the sphenoidal fissure to form the cavernous sinus. 
 Its branches are : 
 
 1. Lachrymal, with the external rectus, sixth nerve to lachrymal gland. 
 
 2. Supraorbital, with the frontal nerve, levator palpebrae, superior rectus. 
 
 3. Arteria centralis retinas, in centre of optic nerve to the retina. 
 
 4. Anterior ethmoidal, with the nasal nerve to ethmoid cells. 
 
 5. Posterior ethmoidal, to the posterior ethmoid cells. 
 
 6. Palpebral arteries, to the upper and lower lids. 
 
 7. Frontal artery, to the inner angle of the eye. 
 
 8. Nasal artery, to the lachrymal sac and caruncula. 
 
 9. Muscular branches, to the muscles of the eye. 
 10. Ciliary arteries, to the iris and choroid coat. 
 Hew would you classify the nerves? 
 
 1 . Special sense : The optic nerve special of vision. 
 
 ( Motor : Third, to all except two muscles. 
 
 2. < Motor : Fourth, to the superior oblique muscle. 
 
 ( Motor : Sixth, to the external rectus muscle. 
 
 T Sensory : Nasal branch of ophthalmic, to the nose and orbit. 
 
 3. < Sensory : Lachrymal branch of ophthalmic, to lachrymal gland. 
 
 ( Sensory : Frontal branch of ophthalmic, to forehead. 
 
 4. Sympathetic, from cavernous plexus, to the ciliary ganglion. 
 
 SUPERIOR LACHRYMAL GLAND 
 INFERIOR LACHRYMAL GLAND 
 
 DUCT FROM SUPERIOR 6LAND 
 
 UPPER EYELID PARTIALLY 
 DIVESTED OF SKIN 
 
 UPPER PUNCTUM 
 
 LACHRYMAL SAC, NEAR ITS FUNDt'S 
 
 COMMON DUCT FORMED BY JUNC- 
 TION OF CANALICULI 
 
 UPPER AND LOWER CANALICULI 
 LOWER PUNCTUM 
 
 FIG. 104. LACHRYMAL APPARATUS. (After Schwalbe. ) 
 
 The lachrymal gland you will find under the external angular process of 
 the frontal bone in the lachrymal fossa. (Fig. 103.) It has an orbital and a 
 palpebral part, a capsule, an artery, and a nerve. 
 
 Define the periorbita and give its functions. 
 
 This is the orbital periosteum. It forms the tarsal ligaments and the limbs of 
 the inner palpebral ligament, lines the floor of the lachrymal groove, forms the 
 trochleafor the superior oblique muscle of the eyeball, assists the orbital fascia in 
 forming a capsule for the lachrymal gland, and sustains the orbital fat. 
 
 Wliat is tJie first structiire you saw on removing the orbital plate of the 
 frontal bone ? 
 
 The periorbita or orbital periosteum, a continuation of the dura mater 
 through the sphenoidal fissure and the optic foramen. 
 
 On removing the periorbita, wliat did you sec f 
 
 1. In the middle we saw the frontal artery, a branch of the ophthalmic, and 
 the frontal nerve, a branch of the ophthalmic division of the fifth nerve, lying on 
 the levator palpebrae muscle. 
 
 2. To the outer side we saw the lachrymal artery, a branch of the ophthalmic 
 
i4 PRACTICAL ANATOMY. 
 
 artery, and the lachrymal nerve, a branch of the ophthalmic division of the fifth 
 nerve, lying on the external rectus muscle. 
 
 3. To the inner side we saw the fourth nerve, called also the patheticus, 
 lying on and supplying the superior oblique muscle with motion, in its course 
 having passed above the levator palpebrae muscle and the frontal nerve. 
 
 Describe the frontal nerve, which you found on t/ie levator palpebrce, and tell 
 what structure intervened bet'cvcen the periorbita and this nerve. 
 
 The intervening structure was the peripheral part of the orbital fascia. It was 
 so thin and translucent that we could see the nerve through the fascia. The 
 frontal nerve is a branch of the ophthalmic part of the fifth nerve. About midway 
 between the optic foramen and the supraorbital foramen it divides into a supra- 
 orbital and a supratrochlear branch. The supraorbital branch leaves the orbit 
 through the supraorbital foramen and supplies the skin of the upper lid, the 
 skin of the forehead, and the pericranium in this same region ; the supratroch- 
 lear branch communicates with the infratrochlear branch of the nasal nerve 
 around the pulley for the superior oblique muscle, branches being given off 
 from this loop to supply the upper lid, forehead, and nose. 
 
 Describe the lachrymal nerve, which you saw on the external rectus muscle. 
 
 It is a branch of the ophthalmic part of the fifth nerve. It gives branches to the 
 lachrymal gland, and to the skin and mucous membrane of the upper lid, and sends 
 a communicating branch to the orbital branch of the superior maxillary nerve. 
 
 Describe the nasal nerve. 
 
 It is a branch of the ophthalmic. It has a most complicated course, which 
 to be learned thoroughly must be studied according to these stages : 
 
 1. The nerve enters the orbital cavity by the sphenoidal fissure. 
 
 2. In its course through the orbit it passes : (i) Between the optic nerve and 
 superior rectus muscle ; (2) between the external rectus muscle and the superior 
 oblique muscle, and arrives at the anterior ethmoidal foramen. In this, its 
 orbital stage, the nerve gives off the long root to the ciliary ganglion, at the 
 sphenoidal fissure, and the long ciliary nerves to the eyeball, as it crosses the optic 
 nerve. At the anterior ethmoidal foramen the nerve gives off the infratrochlear 
 branch, to communicate with the supratrochlear branch of the frontal nerve. 
 
 3. In company with the anterior ethmoidal artery it enters the cranial cavity, 
 by the anterior ethmoidal foramen, crosses the cribriform plate of the ethmoid 
 bone, and leaves the cranial cavity and gains the nasal cavity by the nasal slit, by 
 the side of the crista galli. 
 
 4. The nerve divides in the nasal cavity into septal branches, which are dis- 
 tributed to the upper and front part of the septum nasi, and branches to the 
 outer wall and anterior ends of the two lower turbinals. The end branch of this 
 nerve passes between the cartilage and the end of the nasal bone, supplying the 
 tip and lobe of the nose. 
 
 Describe the motor oculi, or third cranial nerve. 
 
 This nerve is the most important motor nerve to the muscles of the orbit. 
 As the nerve emerges from the cavernous sinus it divides into a superior and 
 an inferior division, which enter the orbit by the sphenoidal fissure. The 
 superior division supplies the levator palpebrae and superior rectus muscles. 
 The inferior division supplies the internal rectus, the inferior rectus, and the 
 inferior oblique. The third nerve supplies with motion the circular fibres of the 
 iris and the ciliary muscle, through the ciliary ganglion. 
 
 Describe the fourth crania! nerve. 
 
 It is called patheticus and trochlear. It enters the orbit by the sphenoidal 
 fissure, passes above the frontal nerve and levator palpebras muscle, and is 
 distributed to the superior oblique muscle. This is the smallest of the cranial 
 nerves. 
 
THE HEAD AND NECK. 149 
 
 Describe the sixth cranial nerve. 
 
 It is called the abducent nerve. It enters the orbit by the sphenoidal fissure, 
 between the two heads of the external rectus, to which muscle it is distributed. 
 
 Describe the optic nerve. 
 
 This is the nerve of the special sense of sight. It is the second cranial nerve. 
 It enters the orbit by the optic foramen, internal to and above the ophthalmic 
 artery. It pierces the ball of the eye and forms the retina. It is surrounded by 
 the ciliary vessels and nerves. To its outer side is the ciliary ganglion. At the 
 optic foramen it is surrounded by the four recti muscles. The arteria centralis 
 retinae pierces its under surface and goes to the interior of the eyeball. The 
 process of dura that surrounds the nerve divides in such a manner as to form a 
 sheath for the nerve, and also the orbital periosteum, inside the orbit. The 
 optic sheath is continuous with the sclerotica. 
 
 Wliat is the orbital fascia? 
 
 It is a variety of connective tissue, being to the contents of the orbit what 
 the deep fascia is to the thigh. It forms a capsule, in conjunction with the peri- 
 orbita, for the lachrymal gland, and sheaths for the muscles, vessels, and nerves. 
 It is connected to the ocular conjunctiva close to the cornea. The muscular 
 sheaths are firmly adherent to the muscles. The insertions of the ocular muscles 
 into the sclerotica are connected together around the whole circumference of 
 the globe. From this attachment this fascial connecting medium is reflected 
 backward in a double layer, forming the fibrous basis of a serous membrane 
 the visceral layer covering the back part of the globe, the parietal lining the 
 postocular fat in the orbit. A layer of endothelial cells completes the serous 
 membrane. Here we have a visceral layer, a cavity, and a parietal layer, the 
 three cardinal points in any serous apparatus. This reflected part of the orbital 
 fascia permits free movement of the eyeball, as the head of a bone revolves in its 
 socket, and is known in anatomy as the capsule of Tenon. 
 
 By what is the orbital fascia on the posterior part of the eyeball pierced ? 
 
 It is pierced by the vessels and nerves that supply the globe. 
 
 What muscle did you find immediately under the levator palpebrce ? 
 
 The superior rectus, and under this we found the optic nerve, surrounded by 
 fat, vessels, and nerves. 
 
 Name the muscles of the eyeball and give their function. 
 
 The external rectus abducts the cornea. 
 
 The internal rectus adducts the cornea. 
 
 The superior rectus elevates, adducts, and rotates cornea inward. 
 
 The inferior rectus depresses, adducts, and rotates cornea outward. 
 
 The superior oblique depresses, abducts, and rotates cornea inward. 
 
 The inferior oblique elevates, abducts, and rotates cornea outward. 
 
 The levator palpebrae elevates the upper eyelid. 
 
 Name all the nerves that supply the orbital contents. 
 
 The optic, the nerve of special sense of sight. 
 
 The motor oculi, a motor nerve to all muscles except two. 
 
 The pathetic, a motor nerve to the superior oblique muscle. 
 
 The abducens, a motor nerve to the external rectus muscle. 
 
 The frontal, a branch of the ophthalmic of the fifth nerve. 
 
 The lachrymal, a branch of the ophthalmic of the fifth nerve. 
 
 The supratrochlear branch of the frontal. 
 
 The palpebral branches of the frontal. 
 
 The infratrochlear branch of the nasal. 
 
 The long ciliary branches of the nasal. 
 
 The short ciliary branches of the lenticular ganglion. 
 
 The cavernous sympathetic branches to lenticular ganglion. 
 
150 PRACTICAL ANATOMY. 
 
 The lenticular or ciliary ganglion. 
 
 \VIiere is tlic ciliary ganglion located, and how is it formed .' 
 
 It lies between the external rectus muscle and the optic nerve on the outer 
 
 side of the ophthalmic artery. It is the size of a pin's head. It has three 
 
 roots : 
 
 1 . A sensory root from the nasal nerve. 
 
 2. A motor root from the motor oculi nerve. 
 
 3. A sympathetic root from the cavernous sympathetic. 
 Hoiv do the nerves gain access to the orbit ? 
 
 The optic nerve passes through the optic foramen ; all the others pass through 
 the sphenoidal fissure with the ophthalmic vein. 
 
 Name all the structures seen on inspecting the eye of a patient. 
 
 1. The palpebral fissure, a slit between the lids. 
 
 2. The outer and inner canthi, the extremities of the fissure. 
 
 3. The tarsal cartilages, the free margins of the lids. 
 
 4. The cornea, behind, which is the iris. 
 
 5. The pupil, surrounded by the iris.- 
 
 6. The tendo oculi, or inner palpebral ligament. 
 
 7. The lachrymal caruncle, just within the inner can thus. 
 
 8. The superior palpebral fold when the eye is opened. 
 
 9. The inferior palpebral fold when the eye is opened. 
 10. The palpebral and ocular conjunctivae. 
 
 i i. The conjunctival cul-de-sac or fornix. 
 
 1 2. The sclerotica, or white of the eye. 
 
 13. The conjunctival sac. This is the space between the posterior surface of 
 the lid and the eyeball. It is completely covered by conjunctiva. 
 
 A patient gets a cinder in his eye : What nerve or nerves report the pain to the 
 brain f 
 
 The cornea and sclerotica are supplied by the ciliary nerves. The infra- 
 trochlear branch of the nasal nerve supplies the conjunctiva, the lachrymal sac, 
 and the caruncula lachrymalis. The lachrymal nerve sends conjunctival branches 
 to the upper lid. The palpebral branches of the superior maxillary send con- 
 junctival branches to the lower lid. While, then, a number of branches are con- 
 cerned locally, one nerve, the trigeminus or fifth, does terminal work for all, 
 since the lachrymal, nasal, superior maxillary, and the sensory root of the ciliary 
 ganglion are all derived from the fifth nerve. A reflex circuit is completed by 
 the seventh nerve, acting on the orbicularis palpebrarum to close the eye. 
 
 Emissary Foramina and Their Veins. 
 
 Define emissary foramina ami emissary veins. 
 
 Emissary foramina derive their importance from the veins they transmit ; 
 emissary veins are both physiologically and pathologically important. The emis- 
 sary veins are connected centrally to the sinuses in the dura mater ; peripherally 
 they communicate with veins both deep and superficial. From a physiological 
 standpoint these veins regulate indirectly the arterial pressure in the brain, since, 
 in cases of cerebral engorgement, when the internal jugular veins are unable to 
 convey the required amount of blood in the dural sinuses from the brain, the 
 emissary veins deliver large quantities of this venous blood to the superficial or 
 to the deep veins with which they communicate peripherally. This action of the 
 emissary veins has been compared to a safety-valve in mechanics. From a 
 pathological standpoint these veins are conveyers of septic material from areas 
 accessible to the surgeon and physician, to regions beyond the reach of either. 
 Infection in the orbit, posterior nares, and scalp over the forehead reaches the 
 cavernous sinus via the angular and ophthalmic veins. Infection in the face, 
 nose, and teeth reaches the cavernous sinus via the Vesalian vein and pterygoid 
 
THE HEAD AND NECK. 151 
 
 plexus. The conservatism of emissary veins is well illustrated in the profuse 
 epistaxis of children, incident to cerebral congestion. In this case an emissary 
 vein connects centrally the blood in the superior longitudinal sinus with the 
 blood in the mucous membrane of the nose ; the latter, being the weaker structure, 
 gives way, and the arterial pressure in the brain is relieved by a profuse hemor- 
 rhage. The emissary foramina seem to belong more especially to the physio- 
 logical needs of childhood. .The greater number of emissary veins and their 
 foramina disappear as adult years come on. By osteological classification these 
 foramina are inconstant. 
 
 The following table gives a list of the emissary foramina, the central sinuses, 
 and the peripheral veins, between which the emissary veins stand, holding the 
 two together like the handle connects the two globes of a dumb-bell : 
 
 TABULATED LIST OF EMISSARY STRUCTURES. 
 
 FORAMEN. CENTRAL SINUS. PERIPHERAL VEIN. 
 
 Caecum Superior longitudinal, Nasal mucous membrane. 
 
 Carotid canal, Cavernous, Internal jugular vein. 
 
 Parietal, Lateral, Occipital. 
 
 Vesalii, Cavernous, Internal jugular vein. 
 
 Posterior condylar, Lateral, Deep cervical. 
 
 Occipital, Torcular Herophili, Occipital veins. 
 
 Anterior condylar Occipital, Deep cervical. 
 
 Mastoid, Lateral, Occipital veins. 
 
 Sphenoidal fissure Cavernous, Angular and ophthalmic. 
 
 Ovale Cavernous, Pharyngeal and pterygoid. 
 
 How SEPTIC THROMBI REACH THE SINUSES. 
 
 How may a carbuncle of tJie face, or facial erysipelas, or infection of tJie scalp 
 over the forehead result in fatal blood-poisoning ? 
 
 Septic thrombi from these sources- may reach the cavernous sinus and get 
 beyond the reach of the surgeon. The frontal and supraorbital veins unite to 
 form the angular, and this is one of the large tributaries of the facial vein. 
 (Fig. 1 8.) Now, the angular vein communicates with the ophthalmic. The 
 ophthalmic vein passes through the sphenoidal fissure, and is tributary to the 
 cavernous sinus. The angular, facial, and ophthalmic veins contain no valves, 
 hence the blood can pass either forward or backward from the superficial seat of 
 infection to a region beyond the reach of surgical drainage and antisepsis. 
 
 Tell the course septic material from a carious tooth, alveolar abscess, or suppura- 
 tion of the antrum folloius in cases of fatal blood-poisoning- to reach the sinuses in 
 the dura mater beyond the reacli of operative procedure. 
 
 To appreciate an answer to this question you must recall the distribution of the 
 internal maxillary artery to the muscles of mastication, the teeth, the nasal fossae, 
 the meninges, and the palate. Now, the veins returning the blood from these areas 
 take the course of their companion arteries, and the same name as the arteries. 
 The veins from these regions, the small and great meningeal, the supraorbital 
 and posterior dental, the palatine and spheno-palatine, the deep temporal, ptery- 
 goid, and buccal, the lower ophthalmic and Vesalian, all come together on the 
 inner surface of the internal pterygoid muscle to form the pterygoid plexus. 
 This plexus communicates with the cavernous sinus by the Vesalian vein. As 
 these veins contain no valves, septic thrombi originating anywhere in the dental, 
 alveolar, antral, nasal, or palatine regions may spread backward to the cavernous 
 sinus via the Vesalian vein and pterygoid plexus. 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 I prefer to have my students begin a dissection of the upper extremity on 
 the fingers and hand. The liability of these parts to become dry, to say nothing 
 of the great practical importance of this region, is sufficient apology. Any dis- 
 section of the hand without a review of the salient osteological landmarks will 
 be, in a measure, a poor dissection, unsatisfactory alike to teacher and student. 
 The student should become master of the following points in osteology before 
 he begins work on the cadaver : 
 
 OSTEOLOGICAL POINTS ON THE HAND. 
 
 The Carpus and Hand (Figs. 108 and 109). 
 
 Name the points on the bones of the carpus and hand of importance in practical 
 anatomy. 
 
 The carpo-metacarpal articulations. 
 
 The base of the first or thumb metacarpal. 
 
 The base of the second metacarpal, radial side. 
 
 The base of the third metacarpal, radial side. 
 
 The base of the fifth metacarpal, ulnar side. 
 
 The pisiform bone of the carpus. 
 
 The groove in the os trapezium. 
 
 The unciform process of the unciform bone. 
 
 The base of the first thumb phalanx. 
 
 The base of the second thumb phalanx. 
 
 The dorsal bases of index, middle, and ring fingers. 
 
 The dorsal bases of second and third phalanges. 
 
 The palmar bases of second and third phalanges. 
 
 What is the importance of the groove in the os trapezium at the base of the 
 thumb f 
 
 It transmits the tendon of the flexor carpi radialis to its insertion into the 
 base of the index metacarpal bone. 
 
 What is the importance of the base of the fifth metacarpal ? 
 
 On its palmar side is inserted the flexor carpi ulnaris ; on its dorsal the ex- 
 tensor carpi ulnaris. These muscles are antagonized by radial and ulnar carpal 
 extensors. 
 
 Name the radial and ulnar extetisors of tJie carpus. 
 
 There are two radial extensors of the carpus : the extensor carpi radialis 
 longior and brevior, inserted into the bases of the second and third metacarpals 
 respectively, on the radial side. The extensor carpi ulnaris is inserted into the 
 base of the fifth metacarpal on the ulnar side. 
 
 Give the importance of the pisiform bone and the unciform process of the unciform 
 bone on the ulnar side of the carpus, in conjunction ~^ilh t/ic scaphoid and trapezium 
 on the radial side. 
 
 It is these bones that give attachment to the anterior annular ligament of tlu- 
 
 152 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 153 
 
 wrist, a band of deep fascia that binds down the strong flexor tendons of the 
 fingers and thumb, and also preserves the transverse carpal arch. 
 
 Pectoralis major, hooked up 
 
 External jugular vein 
 
 Pectoralis major 
 
 Lymphatics from side of chest 
 
 Pectoral glands 
 
 Basilic vein 
 
 ven r, 
 
 Epitrochlear gland 1 
 ial ulnar ' 
 
 Posterior superficia 
 
 vein 
 
 Median basilic vein 
 Inner set of superficial lym- 
 phatics of forearm 
 
 Deep median vein 
 
 INTERNA L CUTA NEO US 
 NER VE 
 
 Anterior superficial ulnar 
 vein 
 
 Median set of superficial lym- 
 phatics of forearm 
 
 Supraclavicular gland 
 Jugulo-cephalic vein 
 
 Deltoid muscle 
 
 Lymphatics accompanying 
 cephalic vein 
 
 Axillary glands 
 
 Cephalic vein 
 
 Lymphatic vessels of inner 
 side of arm 
 
 Biceps, exposed 
 
 MUSCULO-CUTANEO US 
 NER VE 
 
 Brachial artery 
 Bicipital fascia 
 Median cephalic vein 
 
 Superficial radial vein 
 Superficial median vein 
 
 Outer set of superficial lym- 
 phatic vessels of forearm 
 
 FIG. 105. SUPERFICIAL VEINS AND LYMPHATICS OF THE FOREARM AND ARM. 
 
 What is on the palmar surface of the phalanges ? 
 
 A groove limited laterally by a ridge of bone on each side. The groove is 
 converted into an osseo-aponeurotic canal by a strong covering of deep digital 
 
154 
 
 fascia, called the ligamentum vaginale. In this canal are found the flexor ten- 
 dons, invested by a synovia! membrane called theca. 
 
 ANTERIOR PART. 
 
 Locate on the cadaver : (i) The clavicle ; (2) the sternum ; (3) sterno-clavicu- 
 lar articulation ; (4) acromio-clavicular articulation ; (5) the acromion ; (6) the 
 coracoid process ; (7) the greater tuberosity of the humerus ; (8) the lesser 
 tuberosity of the humerus ; (9) the internal condyle ; (10) the external condyle ; 
 (i i) the radial head 5(12) the clefts of the fingers ; (13) the thenar eminence ; 
 
 INTERNAL 
 CUTANEOUS OF 
 MUSCULO- 
 SPIRAL 
 
 INTERNAL 
 CUTANEOUS 
 
 PALMAR 
 
 CUTANEOUS OF 
 
 MEDIAN 
 PALMAR 
 
 CUTANEOUS OF 
 
 ULNAR 
 
 SUPRA- 
 
 ACROMIAL 
 
 CIRCUMFLEX 
 
 INTERCOSTO- 
 HUMERAL 
 
 TWIG OF 
 INTERNAL 
 
 CUTANEOUS 
 
 CIRCUM-\ 
 FLEX 1 
 
 EXTERNAL 
 CUTANEOUS OF 
 
 MUSCULO- 
 
 SPIRAL 
 
 MUSCULO- 
 CUTANEOUS 
 
 EXTF.RNAL 
 CUTANEOUS 
 
 OF 
 
 MUSCULO- 
 SPIRAL 
 
 MUSCULO- 
 CUTANEOU* 
 
 RADIAL 
 
 PALMAR 
 CUTANEOUS 
 OF RADIAL 
 
 SUPRA- 
 ACROMIAL 
 
 INTERNAL 
 
 cr r TA\EOUS OF 
 
 MUSCULO- 
 SPIRAL 
 INTERCOSTO- 
 HL'MERAL 
 
 NERVE OF 
 WRISBERQ 
 
 INTERNA L 
 CUTANEOUS 
 
 ULNAR 
 
 FIG. 106. DISTRIBUTION OF CUTANEOUS NERVES ON THE ANTERIOR AND POSTERIOR .Asn-rrs 
 
 OF THE SUPERIOR EXTREMITY. 
 
 (14) the hypothenar eminence; (15) the metacarpo-phalangeal articulation; 
 (16) the phalangeal articulations; (17) the pisiform; (18) the unciform pro- 
 cess of the unciform bone. 
 
 Incisions. (i) From the acromion to the end of the middle finger ; (-2) from 
 the sterno-clavicular articulation to the acromion ; (3) from condyle to condyle ; 
 (4 through the metacarpo-phalangeal crease. 
 
 NOTE. In making these incisions care must be taken not to cut too deeply, 
 in order to avoid doing violence to the cutaneous vessels and nerves. Now 
 remove the skin very carefully and expose the following cutaneous nerves and 
 veins : 
 
 I. The ccpJialic vein a continuation of the radial above the elbow. (Fig. 105.) 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 155 
 
 2. The basilic vein a continuation of the ulnar above the elbow. 
 
 3. The superficial radial vein, on radial side of forearm. 
 
 4. The superficial median vein, on midfront of forearm. 
 
 5. The anterior superficial nlnar vein, on ulnar side of forearm. 
 
 6. The posterior superficial ulnar vein, on posterior part of forearm. 
 
 7. The deep median vein, a communicating vessel. 
 
 8. The external jugular vein, seen above the clavicle. 
 
 Cutaneous Nerves. 
 
 1. The palmar cutaneous branch of the ulnar nerve, supplying 1.5 fingers. 
 
 2. The palmar cutaneous branch of the median nerve, supplying 3.5 fingers. 
 
 3. The palmar cutaneous branch of the radial nerve, to ball of thumb. 
 
 THnar portion of palmar bursa 
 Radial portion of palmar buraa 
 
 Anterior annular ligament 
 
 Lumbricalis 
 
 Deep transverse 
 ligament 
 
 Superficial transverse ligament 
 
 FIG. 107. DIAGRAM OF THE GREAT PALMAR BURSA. 
 
 4., The cutaneous branch of the musculo-cutaneous nerve. 
 
 5. The internal cutaneous nerve on internal part of the forearm. 
 
 6. The intercosto-humeral nerve on internal part of the arm. 
 
 7. The cutaneous brancJi of 'the circumflex nerve over insertion of deltoid. 
 
 8. The internal cutaneous branch of the muscido-spiral nerve. 
 
 Directions for Dissecting the Cutaneous Vessels and Nerves. Consult figures 
 105 and 1 06. Plow through the upper fat-bearing strata of the superficial fascia 
 with the forceps never with the scalpel. You will find all the vessels and 
 nerves in the deep layer of the superficial fascia. Divide the fascia in the direction 
 of the vessels and nerves. 
 
 The radial veins converge to form the cephalic vein above the elbow. 
 
156 
 
 PRACTICAL ANATOMY. 
 
 (Fig. 105.) The ulnars converge to form the basilic vein above the elbow. 
 The medians converge to form one large vein. This vein breaks up into the 
 median ccpJialic and median basilic, which join respectively the cephalic and 
 basilic veins. (Fig. 105.) 
 
 Observe that the internal cutaneous nerve passes behind the median basilic 
 vein ; that the cutaneous branch of the musculo-cutaneous nerve passes behind the 
 median cephalic vein. (Fig. 105.) 
 
 Find the deep median vein, piercing the deep fascia near the bifurcation of 
 
 SEMILUNAR 
 
 ISIFORM 
 EIFORM 
 
 Extensor carpi 
 radialis longior 
 
 Extensor carpi 
 radialia brevier 
 
 Extensor carpi ulnarii 
 
 Extensor oommunis digitorum 
 
 Extensor oommunis digitorum 
 THIRD, UNGUAL, OR TERMINAL PHALANX 
 
 FIG. 108. THE LEFT HAND. (Dorsal surface.) 
 
 the superficial median vein. Trace it to the ulnar vein below the deep fascia. 
 (Fig. 105.) 
 
 Note that the median basilic vein crosses the lower part of the bracliial 
 artery. Notice also the bicipital fascia between these two structures. (Fig. 
 105.) This vein was formerly a favorite in bleeding. The basilic vein termin- 
 ates in the axillary ; the cephalic in the axillary vein also. Find the cephalic 
 vein in a groove between the pectoralis major and deltoid muscles with the 
 'Irscending branch of the acromio-thoracic artery below the clavicle. 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 157 
 
 The cutaneous branch of the musculo-cutaneous nerve supplies the skin over 
 the insertion of the biceps ; inasmuch as the supinator longus is also a flexor of 
 the forearm, and receives a part of its nerve-supply from the musculo-cutaneous 
 nerve, the skin over the insertion of this muscle is also supplied by the same 
 nerve. See Hilton's law in the introductory chapter. 
 
 Plexor brevis 
 
 pullieia 
 
 Abductor pollicis 
 
 Flexor carpi ulnaris 
 Abductor minimi 
 digiti 
 
 Flexor brevis and 
 opponens minimi 
 digiti 
 
 Flexor carpi 
 ulnaris 
 
 Adductor pollicis 
 
 Opponens minimi 
 
 digiti 
 
 Abductor and 
 flexor brevis 
 minimi digiti 
 
 Opponens pollicis 
 
 Occasional insertion into trapezium 
 Extensor oasis metacarpi pollicis 
 
 Flexor carpi radialis 
 Interosseus primus volaris 
 Opponens pollicis 
 
 Flexor brevis and 
 Abductor pollicis 
 
 Flexor brevis and 
 Adductor pollicis 
 
 Flexor longua 
 pollicis 
 
 Flexor sublimis digitorum 
 
 Flexor profundus digitorum 
 
 FIG. 109. THE LEFT HAND. (Palmar surface.} 
 
 DEEP FASCIA OF THE HAND. 
 
 The deep fascia fascia profunda lies immediately under the superficial 
 fascia, being in intimate trabecular relation with the deep layer of the superficial 
 fascia. In the palm of the hand it is very dense and heavy ; over the thenar and 
 hypothenar eminences it is very thin. 
 
 The deep fascia takes the following special names : 
 
 1. The anterior annular ligament in front of wrist. 
 
 2. The palmar fascia in palm of the hand. 
 
 3. The ligamenta vaginales on flexor side of the digits. 
 
158 
 
 PRACTICAL ANATOMY. 
 
 4. Internal and external intermuscular fascia. 
 
 5. The posterior annular ligament. 
 
 6. The dorsal fascia of the hand. 
 
 Flexor carpi radialis 
 
 Flexor 
 carpi ulnaris 
 
 Deep fascia of 
 forearm 
 
 Extensor oasis metacarpi pollicis 
 
 ^ Opponens pollicis 
 
 Abductor pollicis 
 
 Flexor brevis pollicis 
 Adductor Follicle 
 
 First lum- 
 
 bricalis 
 - First dorsal 
 interos- 
 
 seoua 
 
 Iiigamentum vaginale 
 
 Flexor sublimis digitorum 
 
 Flexor profundua digitorum 
 
 Flexor profundus 
 digitorum 
 
 FIG. no. THE SUPERFICIAL MUSCLES OK THE PALM OK THE HAND. 
 
 Dissection of the Jiand in which find the following : 
 
 1. The palmar fascia and palmaris brevis muscle. 
 
 2. The flexor tendons and their sheaths and vincula. 
 
 3. The digital nerves and arteries and digital veins. 
 
 4. The superficial palmar arch and its branches on flexor tendons. 
 
 5. The thecal culs-de-sac, synovial in the ligamenta va;^inalis. 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 *59 
 
 6. The anterior annular ligament on front of carpus. 
 
 7. The musculi lumbricales on flexor tendons. 
 
 8. The thenar and hypothenar muscles about thumb and little finger. 
 
 9. The deep palmar arch and branches below the flexor tendons. 
 
 10. The deep palmar branch of the ulnar nerve with deep arch. 
 
 1 1. The dorsal interossei muscles. 
 
 12. The ulnar nerve in the hand, supplying 1.5 fingers. 
 
 13. Deep palmar arch and branches of ulnar nerve in the hand. 
 
 14. The median nerve in the hand, supplying 3.5 fingers. 
 
 15. The radial and ulnar arteries in the hand, forming the arches. 
 
 1 6. The palmar interosseous muscles on the palmar surface. 
 
 Dissection. The palmar fascia is the deep fascia of the flexor surface of the 
 
 MEDIAN NERVE 
 
 BRANCH TO MUSCLES 
 OF THUMB 
 
 COLL A TERAL 
 BRANCHES OF 
 MEDIAN 
 
 ULNAR NERVE 
 
 COMMUNICA TION 
 BETWEEN MEDIAN 
 AND ULNAR 
 
 COLLATERAL 
 BRANCHES OF 
 ULNAR 
 
 FIG. in. SUPERFICIAL NERVES OF 'IHE PALM. (Ellis.) 
 
 hand from the annular ligament above to the clefts of the fingers below. Having 
 removed the skin of the palm, and noticed the granular fat in the superficial 
 fascia thereof, you are now ready to study the palmar fascia. This fascia has 
 three divisions : (i) An inner thin part that covers the muscles forming the ball 
 of the little finger ; (2) an outer thin part that covers the muscles forming the 
 bail of the thumb ; (3) a central strong portion, investing the central distributory 
 region of the hand, in such a way as to protect the vessels and nerves for the 
 supply of the fingers and adjacent structures. The palmar fascia is continuous 
 above with the anterior annular ligament, and below with the ligamenta vaginales 
 in the form of heavy protective sheaths for the flexor tendons of all the fingers. 
 Figure 1 10 shows this ligamentum vaginale still intact in the little finger. 
 
 The Flexor Tendons and Ligamenta Vaginales. Cut through the very 
 
i6o 
 
 PRACTICAL ANATOMY. 
 
 centre of the dense ligaincnta vagitialcs and you will come down on the two 
 flexor tendons. Notice that the tendon of the flexor profnndus digitontui passes 
 through a slit in the tendon of the flexor snbliinis digitornin. (Fig. 1 10.) The 
 former is inserted into the base of the third, the latter into the base and sides of 
 the second phalanx. Now gently separate these tendons and you will see (i) 
 the visceral layer of synovial membrane on the tendons, and (2) the vincula 
 delicate tendinous cords. 
 
 Flexor carpi 
 ulnaria 
 
 Abductor minimi 
 digiti 
 
 Flexor sublimis 
 digitorum 
 
 Flexor brevis 
 minimi digiti 
 
 Flexor prot'undus 
 digitorum 
 
 Extensor oasis metacarpi pollicis 
 Flexor carpi radialis 
 Extensor brevis pollicis 
 
 Abductor pollicis 
 
 Opponens pollicis 
 
 Abductor 
 pollicis 
 Flexor brevis 
 pollicis 
 
 
 FIG. 112. THE DEEPER MUSCLES OK THE PALM OK THE HAND. 
 
 These heavy, deep fascial sheaths you have just cut through are lined by 
 synovial vaginal membrane called the theca. In the thumb and little finger these 
 synovial cavities communicate with the ulnar and radial palmar bursae above the 
 annular ligament. (Fig. 107.) 
 
 The thecre for the remaining fingers terminate in thecal culs-de-sac opposite 
 the metacarpo-phalangeal articulations. (Fig. 107.) 
 
 Infection in the thumb and little finger thus is liable to travel beyond the 
 annular ligament, while in the other fingers it would be arrested at the culs-de-sac. 
 
SHOULDER, ARM, FOREARM, AND HAND, 
 
 161 
 
 A case of unusual interest, bearing on this point, reported by Dr. David Loring, 
 of Valparaiso, Indiana, is as follows : " Infection ensued where a patient thrust a 
 nail through the anterior annular ligament. One by one all the carpal bones, the 
 bones of the thumb and the little finger, and the greater part of the metacarpals 
 disappeared by suppuration. At the present time the patient is well, and has the 
 bones of all the fingers between the thumb and little firmer." This case is of 
 
 Anterior inlerosseous 
 
 Radial artery 
 
 Anterior radial carpal 
 
 Svperficial rolar 
 Posterior radial carpal 
 Radial artery at wrist 
 
 Dorsalis potUcis 
 
 MKtacar/nil or 
 
 first dorsal 
 
 inlerosseous 
 
 Princepspollicis 
 
 Dorsalis indicts 
 Jladialis indicis 
 
 First dorsal branch of collateral 
 digital 
 
 Second dorsal branch of collateral 
 digital 
 
 Anastomosis of collateral digital 
 arteries about matrix of nail 
 and pulp of finger 
 
 Ulnar artery 
 
 Anterior ulnar 
 carpal 
 
 Posterior ulnar 
 carpal 
 
 Deep ulnar 
 Superficial arch 
 
 Carpal recurrent 
 
 Posterior communi- 
 cating or perforat- 
 ing 
 
 Palmar interosseous 
 
 Second, third, and 
 fourth palmar 
 digital 
 
 Second and third 
 dorsal interosseous 
 
 First palmar digital 
 
 Anterior communi- 
 cating or perforat- 
 ing 
 
 FIG. 113. ANASTOMOSES AND DISTRIBUTION OF THE ARTERIES OF THE HAND. 
 
 interest because the pathological process followed to the letter the anatomical 
 rule. 
 
 The vincula will be seen between the flexor tendons. They are delicate, sil- 
 very, tendinous threads. They aid the capillaries in passing from -one tendon to 
 another. They are, then, mechanical devices for the support of the capillaries 
 that nourish the synovial membrane. In some cases the vessels which they 
 support are injected, and can be seen by the unaided eye. 
 
 The palmaris brevis muscle (Fig. 110) arises from the annular ligament 
 
1 62 PRACTICAL ANATOMY. 
 
 and palmar fascia, and is inserted into the skin of the hypothenar eminence. It 
 is a corrugator of the integument. 
 
 The anterior annular ligament (Fig. 1 1 1) has passing under it the follow- 
 ing structures : 
 
 1. The median nerve and its nutrient artery arteria comes nervi mediani. 
 
 2. The flexor sublimis digit or nm musculus perforatus. 
 
 3. The flexor prof undus digitorum musculus perforans. 
 
 4. The flexor longus po llicis between the heads of the flexor brevis. 
 
 To the inner side of the anterior annular ligament, and intimately related 
 thereto, you will find the flexor carpi ulnaris ; to the outer side, the flexor 
 carpi radialis. Inserted into the anterior annular ligament, and passing in 
 front of the same, is the palmaris longus muscle. (Fig. 1 10.) To the ulnar 
 side is the ulnar, and to the radial side is the radial, artery. (Fig. 117.) 
 This anterior annular ligament is a specialized part of the deep fascia. It is 
 attached internally to the pisiform bone and unciform process of the unciform 
 bone; externally, to the scaphoid tuberosity and os trapezium. (Fig. 109.) 
 Cut through the annular ligament ; pull the sides forcibly apart as far as pos- 
 sible. There are two portions of the palmar bursa : (i) The radial, correspond- 
 ing to the flexor longus hallucis ; (2) the ulnar, corresponding to the flexor 
 sublimis digitorum and flexor profundus digitorum. (Fig. 107.) 
 
 To Dissect the Median Nerve in the Hand (Fig. 1 1 1). You will now see the 
 median nerve, as large as a lead-pencil, lying on the flexor sublimis digitorum. 
 This nerve is involved in the synovial membrane, and it will require the aid of 
 the forceps to liberate the same. Place your left index finger under the nerve, 
 carefully lifting the same upward ; now begin to trace out the following branches 
 (Fig. in) : (i) To the thumb ; (2) to the index finger, the middle finger, and 
 radial side of the ring finger ; (3) a communicating branch to thje ulnar nerve. 
 You will see these branches given off from an enlargement. Trace the branches 
 downward and observe them passing behind the superficial palmar arch. (Figs. 
 1 1 1 and 1 13.) 
 
 The branches of the median nerve, after passing behind the superficial palmar 
 arch, accompany arterial branches of the superficial and deep palmar arches to 
 the fingers. (Fig. in.) These arteries and nerves are called digital branches. 
 Note that at the superficial palmar arch the nerves lie behind, but in the fingers 
 the nerves lie in front of, the arteries. Trace these digital arteries and nerves 
 to the ends of the finger, and see the distal digital anastomotic arterial arch. 
 (Fig. 1 13.) 
 
 The Ulnar Nerve in the Hand. Find the ulnar nerve crossing the annular 
 ligament (not under it). It lies to the ulnar side of the ulnar artery, and some- 
 what deeper. Trace it down and find it dividing into two branches : (i) The 
 superficial palmar ; (2) the deep palmar. The former gives off branches to the 
 skin, to the palmaris brevis muscle, and digital branches which accompany 
 arteries to the little finger and one-half of the ring finger. Trace these branches 
 to the finger end and observe the distal digital anastomotic nerve loop. ( Fig. 
 ill.) The deep palmar branch of the ulnar nerve accompanies the deep arch, 
 and will be described in its proper place on page 164. 
 
 The musculi lumbricales (Fig. 112) are four in number. Cut the tendons 
 of the flexor sublimis as shown in figure 112. These muscles arise from the 
 tendons of the flexor profundus digitorum muscle. Trace them on the thumb 
 side, to the extensor communis digitorum, where they are inserted. The ulnar 
 two interossei muscles are supplied by the ulnar, the radial two by the median, 
 nerve. 
 
 The thenar muscles, or muscles of the thumb (Figs. 109 and 114): 
 
 i. The abductor pollicis, abducts first phalanx. 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 163 
 
 2. The flexor brevis pollicis, flexes first phalanx. 
 
 3. The opponens pollicis, acts on metacarpal. 
 
 4. The adductor pollicis, adducts the first phalanx. 
 
 The abductor pollicis (Fig. iio)is easily isolated. Cut the same near its 
 insertion, and turn it aside so as to preserve the nerve-supply. (Figs. 109 and 
 114.) This muscle arises from the bone at the base of the thumb the os 
 trapezium and the annular ligament. It is inserted into the base of the thumb, 
 proximal phalanx. (Fig. 109.) 
 
 The opponens pollicis is inserted into the whole length of the thumb meta- 
 carpal bone. (Fig. 109.) It arises from the os trapezium and annular ligament. 
 (Fig. 114.) 
 
 Flexor carpi 
 ulnaris 
 
 Pronator quadratus 
 
 Abductor pollieis 
 
 Outer head of flexor 
 brevis pollicis 
 
 Inner head of flexor 
 
 breyis pollieis (first 
 
 division) 
 
 Opponens pollicis 
 Inner head of flexor 
 
 breyis pollicis (third 
 
 division) 
 
 Inner head of flexor 
 breyie pollicis (second 
 division) 
 
 Adductor pollicis 
 
 Dorsal interoaseous 
 
 Third palmar 
 interosseoua 
 
 Fourth dorsal 
 mterosseous 
 Second palmar iuterosseous 
 
 First palmar interoaseous 
 Third dorsal intsrosseous 
 
 Second dorsal interoaseous 
 
 FIG. 114. THE PRONATOR QUADRATUS AND DEEP VIEW OF THE PALM. 
 
 Tlie flexor brevis pollicis has two heads, and between these two heads lies the 
 tendon of the flexor longus pollicis muscle. The outer, or more superficial head 
 (Fig. 114), arises from the os trapezium and annular ligament, and is inserted 
 into the base of the first thumb phalanx on the outer side. (Fig. 109.) The 
 deep or inner head has two parts : (i) A small part that arises from the first 
 metacarpal bone ; (2) a large part that arises from the annular ligament, the os 
 magnum, and the second and third metacarpals. (Fig. 1 14.) 
 
 This latter is described by some authors as the oblique part of the adductor 
 pollicis. The deep part of the flexor brevis is inserted into the base of the first 
 thumb phalanx on the inner side. 
 
164 
 
 PRACTICAL ANATOMY. 
 
 The adductor pollicis is the remaining muscle. It arises from the mctacarpal 
 bone of the middle finger, the lower two-thirds. It is inserted into the base of 
 the first thumb phalanx on the inner side. (Fig. 1 14.) 
 
 Nerve-supply. The median nerve supplies the abductor pollicis, the opponens, 
 and the outer head of the flexor brevis pollicis. The ulnar nerve, by its deep 
 palmar branch, will supply all the remaining muscles of the hand, all the inter- 
 ossei muscles, the two ulnar lumbricals, the little finger group of small muscles, 
 the adductor pollicis, and the inner head of the flexor brevis pollicis. Now 
 trace out and review the branches of the median nerve to the thumb. 
 
 The hypothenar muscles, or muscles of the little finger (Fig. 114): 
 
 1. The abductor minimi digiti abducts the little finger. 
 
 2. The flexor brevis minimi digiti bends the first phalanx. 
 
 3. The opponens minimi digiti bends the metacarpal. 
 
 FIG. 115. THE PALMAR INTEROSSEI. 
 
 The abductor minimi digiti arises from the pisiform bone. (Fig. 109.) 
 inserted into the base of the first phalanx of the little finger. (Fig. 109.) 
 and turn aside, and expose the two remaining muscles the flexor brevis minimi 
 digiti and the opponens minimi digiti. 
 
 Note, as you turn this muscle aside, the abductor minimi digiti the d 
 palmar nerve going to join the deep palmar arterial arch from the radial arte 
 (Fig. 1 1 6), whose course it will now follow. 
 
 The flexor brci'is minimi digiti arises from the unciform process of the unci- 
 form bone and annular ligament. It is inserted into the base of the first phalan 
 of the little finger. (Fig. 109.) 
 
 The opponens minimi digiti arises from the unciform process of the uncifor 
 bone and annular ligament. It is inserted into the whole length of the met 
 carpal bone of the little finger. Trace branches from the deep palmar branch 
 the ulnar nerve to this group of muscles. (Fig. 1 1 1.) 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 165 
 
 The Palmar Interossei Muscles (Figs. 114 and 115). These are three in 
 number. They are physiological adductors. They arise from one side of the 
 metacarpal bone corresponding to the finger, into the base of whose proximal 
 phalanx they are inserted. They are inserted into the bases of the proximal 
 phalanges of the index, little, and ring fingers in such a way as to adduct these 
 fingers to the middle finger. Trace branches to them from the deep palmar 
 branch of the ulnar nerve. 
 
 The Deep Palmar Branch of the Ulnar Nerve. You have seen the ulnar 
 
 Anterior inter osseous 
 
 Radial artery 
 
 Anterior radial carpal 
 
 Superficial volar 
 
 Posterior radial carval 
 Radial artery at wrist 
 
 Dorsalis pollicia 
 
 Metacarpal or 
 
 first dorsal 
 
 iiiterosseorts 
 
 Pi-inceps pollici-s 
 
 Dorsalis indicis 
 Radialis indicis 
 
 Ulnar artery 
 
 Anterior ulnar 
 carpal 
 
 Posterior ulnar 
 carpal 
 
 Deep ulnar 
 Superficial arch 
 
 Carpal recurrent 
 
 Posterior communi- 
 cating or perforat- 
 ing 
 
 Palmar inlerosseous 
 
 Second, third, and 
 fourth palmar 
 digital 
 
 Second and third 
 dorsal interosseous 
 
 First palmar digital 
 
 A nterior communi- 
 cating or perforat- 
 ing 
 
 First dorsal branch of collateral 
 digital 
 
 Second dorsal branch of collateral 
 digital 
 
 Anastomosis of collateral digital 
 arteries about matrix of nail 
 and pulp of finger 
 
 FIG. 116. ANASTOMOSES AND DISTRIBUTION OF THE ARTERIES OF THE HAND. 
 
 nerve crossing the anterior annular ligament, and dividing, below the pisiform 
 bone, into superficial and deep palmar branches. (Fig. in.) You traced the 
 superficial branches to the palmaris brevis, the skin over the hypothenar emi- 
 nence, and to the little finger and half the ring finger. (Fig. 1 1 1.) You will now 
 trace in review the deep palmar branch, between the abductor minimi digiti and 
 flexor brevis minimi digiti, and see it join company with the deep palmar arterial 
 arch, and send off branches to these muscles : 
 
1 66 PRACTICAL ANATOMY. 
 
 1. The abductor minimi digiti muscle. 
 
 2. The flexor brevis minimi digiti muscle. 
 
 3. The opponens minimi digiti muscle. 
 
 4. The two ulnar lumbricales muscles. 
 
 5. The four dorsal interossei muscles. 
 
 6. The three palmar interossei muscles. 
 
 7. The adductor pollicis muscle. 
 
 8. The inner head of the flexor brevis pollicis. 
 
 THE RADIAL AND ULNAR ARTERIES IN THE HAND (Fig. 1 16). It now remains 
 to reduce to its simplest terms the blood-supply of the whole hand. 
 
 The ulnar artery crosses the anterior annular ligament. Below the pisiform 
 bone it divides into (i) the superficial arch and (2) the deep ulnar branch. The 
 superficial arch crosses the palm, resting on the flexor tendons under cover of the 
 palmar fascia, and terminating by anastomosis in the superficial volar branch ot 
 the radial artery. From the arch are given off the first, second, third, and fourth 
 palmar digital branches that supply the second, third, fourth, and fifth fingers 
 with blood. (Fig. 116.) 
 
 The radial artery passes to the back of the hand, under the three extensor 
 muscles of the thumb ; passes between the two heads of the first dorsal interos- 
 seous muscle ; crosses the palm beneath the flexor tendons, and terminates, by 
 anastomosis, in the deep ulnar artery. From this arch are given off five palmar 
 interosseous arteries. Three of these the three inner go to the clefts of the 
 fingers, where they unite with the palmar digital brandies from the superficial 
 palmar arch. The two outermost branches go to the thumb and index finger 
 under the special names of prince ps pollicis and radialis indicis. (Fig. 1 16.) 
 
 Carpal arteries are four in number: two from the radial artery the anterior 
 and posterior radial carpal ; two from the ulnar the anterior and posterior ulnar 
 carpal. 
 
 The anterior and posterior perforating arteries communicate, through the 
 hand, with the dorsal interosseous arteries. These are arteries from an arch 
 formed on the back of the carpus by anastomosis between the radial and ulnar 
 posterior carpals. 
 
 Where would yon look for tJic cephalic vein in the vicinity of the shoulder? 
 
 Between the deltoid and pectoralis major muscles ; the vein is in a groo\ 
 with a small artery the descending branch of the acromio-thoracic arter 
 (Fig. 105.) 
 
 How and where do the superficial, radial, median, and nlnar veins terminati 
 
 They terminate opposite the elbow by changing their names. 
 
 The radial above the elbow is called the cephalic vein. 
 
 The ulnar above the elbow is called the basilic vein. 
 
 The median breaks up near the elbow into the median basilic and cephalic. 
 
 What are the vend' coinites / 
 
 The two companion veins attending deep arteries in the extremities of 
 body, below the knee and below the elbow. 
 
 Hcnv do the superficial veins communicate with the vctne comites / 
 
 By perforations in the deep fascia. H\ these communicating veins the circ 
 ation internal to or below the deep fascia is equali/ed to the circulation cxtci 
 to the deep fascia. 
 
 If yon were going to draw blood from a patient's arm, wliy would yon select the 
 median cephalic vein in preference to the median basilic vein for venesection / 
 
SHOULDER, ARM, FOREARM, AND HAND. 167 
 
 The median basilic vein lies on the brachial artery, which latter would be 
 endangered were this vein selected. 
 
 Suppose you employ the median basilic vein in venesection, and accidentally cut 
 the brachial artery, and your patient dies from hemorrhage: In this case w mat 
 ground for action for damages would relatives of deceased liavc that you could not 
 possibly circumvent ? 
 
 The ground of want of ordinary care. The cephalic vein would have 
 answered the venesection purpose, and its employment would not have endan- 
 gered your patient's life. Under the law, a physician must possess ordinary skill 
 and exercise ordinary care. 
 
 Can you say anything regarding any cutaneous nerves liable to be injured in 
 phlebotomy of the median cephalic and median basilic veins f 
 
 The internal cutaneous nerve crosses the median basilic vein ; the musculo- 
 cutaneous nerve terminal crosses the median cephalic either may be injured. 
 
 Name the great nerve-trunks that supply the skin of the hand with sensation. 
 
 The median gives palmar and digital branches to 3.5 fingers, radial side. 
 
 The ulnar gives palmar and digital branches to 1.5 fingers, front and back. 
 
 The musculo-spiral, radial nerve, supplies 3.5 fingers dorsally. 
 
 Have the median, ulnar, and musculo-spiral nerves any articular distribution in 
 the joints of the hand ? 
 
 Yes ; they supply joints between the phalanges the metacarpo-phalangeal, 
 the carpo-metacarpal, the intermetacarpal, the medio-carpal, and the radio-carpal. 
 
 Is there any systematic distribution of articular nen>es f 
 
 Yes ; a nerve-trunk that supplies a muscle that moves a joint supplies the 
 joint as well. The inferior radio-ulnar joint is pronated by the pronator quad- 
 ratus, and supinated by the supinator longus. To determine the nerve-supply to 
 this joint, you ascertain the nerve-supply to the muscles that move the joint. In 
 this particular case the median and musculo-spiral nerve-trunks supply the 
 pronator quadratus and supinator longus muscles respectively ; these same nerves 
 supply the joint. 
 
 Give attachments of the anterior annular ligament and tell ivhat structures pass 
 under the same. 
 
 This ligament is a specialized part of the deep fascia. It is attached exter- 
 nally to the scaphoid bone and os trapezium ; internally to the pisiform bone and 
 the unciform process of the unciform bone. Under this ligament pass the 
 median nerve, with its median artery, the flexor longus pollicis, the flexor prp- 
 fundus digitorum, and the flexor sublimis digitorum. 
 
 Name, locate, and give importance of three surgical areas of the fingers. 
 
 (i) The central, in which are found the tendons of the flexors in their synovial 
 sheath, called theca. (2) On each side of this tendinous area is a neuro- vasal area, 
 in which are found the digital arteries and nerves that supply the fingers with 
 blood and sensation respectively. 
 
 Why is infection of the little finger or thumb more dangerous than infection of 
 the fingers between these two extremes. 
 
 The vaginal thecal sheaths of synovial membrane of these extremes are in 
 communication with the great palmar bursae under the anterior annular ligament. 
 Give the symptoms in paralysis of the ulnar nerve. 
 
 There would be loss of sensation and motion in those parts to which this 
 nerve is distributed, as follows : (i) Loss of sensation in the skin of the little 
 finger and the ulnar half of the ring finger and in the corresponding articulations ; 
 (2) loss of motion in the flexor carpi ulnaris and in half of the flexor profundus 
 digitorum muscles ; (3) loss of motion in all the interossei muscles and in the 
 two lumbricals on the ulnar side of the hand ; (4) loss of motion in the flexor brevis 
 minimi digiti, in the abductor minimi digiti, and in the opponens minimi digiti ; 
 
1 68 PRACTICAL ANATOMY. 
 
 (5) loss of motion in the adductor pollicis and in the ulnar head of the flexor 
 brevis pollicis ; (6) loss of sensation in all the intermetacarpal joints. 
 
 Give symptoms in paralysis of the median nerve. 
 
 (i) Loss of sensation in the thumb, index, middle, and half the ring finger, 
 on the palmar surface, and about the roots of the nails of the dorsal surface ; 
 (2) loss of motion in all the muscles of the anterior part of the forearm, except 
 the muscle and a half supplied by the ulnar nerve, as previously explained ; (3) 
 loss of motion in the two lumbrical muscles on the radial side of the hand, and 
 loss of motion in the outer head of the flexor brevis pollicis, in the opponens 
 pollicis, in the abductor pollicis. 
 
 Describe the blood-supply of the hand. 
 
 The ulnar and radial arteries terminate in the superficial and deep palmar 
 arches respectively. These arches give off branches to the hand and fingers. 
 (Fig. 1 1 6.) 
 
 Describe the superficial palmar arch. 
 
 This arch is a continuation of the ulnar artery across the hand. It anasto- 
 moses with the superficialis volae a branch of the radial artery to complete the 
 arch. The arch may be completed by anastomosis with the radialis indicis or 
 princeps pollicis, both branches of the radial artery also. The superficial arch 
 gives off four branches called first, second, third, and fourth palmar digital 
 branches when enumerated toward the thumb. The first palmar digital artery 
 supplies the ulnar side of the little finger ; each of the three others divides into two 
 collateral digital branches. The radial side of the index finger is supplied by the 
 radialis indicis ; the thumb by the princeps pollicis. The digital branches from 
 the superficial arch are joined, opposite the clefts of the fingers, by (i) the palmar 
 interosseous, branches of the deep palmar arch ; (2) by the inferior perforating 
 arteries from the dorsum of the hand. 
 
 Describe the deep palmar arch. 
 
 This arch is a continuation of the radial artery across the hand. It anasto- 
 moses with the deep branch of the ulnar artery. (Fig. 116.) It begins at the 
 first interosseous space, and rests on the metacarpal bones close to their carpal 
 ends. The arch is attended by the deep branch of the ulnar nerve as described 
 on page 164. The deep arch gives off three palmar interosseous arteries, which 
 inosculate with the digital branches of the superficial arch at the clefts of the 
 fingers. All the digital branches are attended by collateral nerve branches of the 
 median and ulnar nerves. 
 
 THE FOREARM. 
 
 In this region you must review the osteology of the radius and ulna, and 
 become familiar with eminences, depressions, that are associated with the origin, 
 insertion, and location of muscles. You must be able to name all the articular 
 surfaces, and give the rule of occupancy for their nmes. You must name tech- 
 nically all articulations, and give the rule for writing compound words. 
 
 The Radius (Fig. 124). 
 
 Name tlic important points on t/iis bone concerned in practical anatomy. 
 
 The radial head and its concave and convex articular surfaces. 
 
 The bicipital tuberosity for the tendon of the biceps and for a bursa. 
 
 The ulnar articular surface for the lesser sigmoid cavity of the ulna. 
 
 The humeral articular surface for articulation with the capitellum. 
 
 
SHOULDER, ARM, FOREARM, AND HAND. 169 
 
 The neck of the radius located above the bicipital tuberosity. 
 
 The oblique line of the radius a very important structure. 
 
 The styloid process, with base and apex for ligament and muscle. 
 
 The sigmoid cavity, for articulation with the head of the ulna. 
 
 The semilunar and scaphoid articular surfaces. 
 
 The nutrient foramen, directed upward according to rule. 
 
 The interosseous border, for the interosseous membrane. 
 
 The anterior surface, occupied by deep flexor muscles. 
 
 The posterior surface, occupied by deep extensor muscles. 
 
 The outer surface, occupied by muscles. 
 
 Describe tlie anterior surface of the radius. 
 
 The oblique line of the radius extends from the bicipital tuberosity to the 
 insertion of the pronator radii teres on the outer border of the bone. (Fig. 124.) 
 This line may be viewed as consisting of three lips : (i) An upper one, into which 
 the supinator brevis is inserted ; (2) a middle one, from which the radial head 
 of the flexor sublimis digitorum muscle takes its origin ; (3) an inferior one, from 
 which the flexor longus pollicis takes its origin. This surface gives origin 
 below the oblique line to the flexor longus pollicis and insertion to the pronator 
 quadratus. 
 
 Wliat can you say of the external surface of tJie radius ? 
 
 Its upper one-half is occupied by the supinator brevis and pronator radii teres ; 
 its lower one-half is overlapped by the radial extensors of the carpus, and crossed 
 by the extensor ossis metacarpi pollicis and extensor brevis pollicis ; this latter 
 muscle is also called extensor primi internodii pollicis. 
 
 What can you say of the posterior surface of the radius f 
 
 Its upper one-third gives origin to the radial part of the extensor ossis meta- 
 carpi pollicis and the extensor primi internodii pollicis ; the part of the bone 
 below this is covered by the tendons of the two preceding muscles. 
 
 The Ulna. (Fig. 124.) 
 
 Name the important bony parts of the ulna and give their importance in prac- 
 tical anatomy. 
 
 The olecranon process, for the insertion of the triceps muscle. 
 
 The coronoid process, for the insertion of brachialis anticus muscle. 
 
 The greater sigmoid fossa, for articulation with the humerus. 
 
 The lesser sigmoid fossa, for articulation with the radius. 
 
 The oblique line, for attachment of the supinator brevis muscle. 
 
 The interosseous ridge, for attachment of the interosseous membrane. 
 
 The styloid process (apex), for internal lateral ligament of wrist. 
 
 The head articulates with the ulnar sigmoid cavity of the radius. 
 
 The base of the styloid process, for the insertion of the supinator longus. 
 
 The anterior surface of the ulna is for muscular origin. 
 
 The inner surface of the ulna is for muscular origin. 
 
 The posterior surface of the ulna is for muscular origin. 
 
 Explain the anterior surface of the ulna. 
 
 It has the nutrient foramen, which, according to the rule, is directed toward 
 the elbow. It gives origin to the flexor profundus digitorum and pronator 
 quadratus muscles. This surface is limited by the anterior border, the interos- 
 seous border, and an oblique line. 
 
 What can you say of the internal surface of the ulna ? 
 
 It is occupied by the flexor profundus digitorum in its upper three-fourths ; 
 the remainder of this surface of the ulna is subcutaneous. 
 
 What can be said of the posterior surface of the ulna ? 
 
 This is the most difficult part of the bone, but must be mastered before you 
 can appreciate the attachment of certain muscles. This surface is subdivided by 
 
170 PRACTICAL ANATOMY. 
 
 two lines, an oblique and a vertical one, into three smaller surfaces. Above the 
 oblique line, which runs from the lesser sigmoid cavity to the posterior border of 
 the bone, is the anconeus muscle. To the oblique line the supinator brevis 
 muscle is attached. The surface below the oblique line is divided by a vertical 
 line into an internal and an external portion. 
 
 What can you say of the portion of the posterior surface of the ulna internal 
 to the vertical line ? 
 
 It gives origin to the extensor carpi ulnaris muscle. 
 
 What can you say of the portion of the posterior surface of the ulna external 
 to the vertical line ? 
 
 It gives attachment to the supinator brevis, the extensor ossis metacarpi pol- 
 licis, the extensor longus pollicis, and the extensor indicis muscles. 
 
 Does t/ie head of the ulna enter into the formation of the wrist-joint f 
 
 No ; the triangular fibro-cartilage intervenes. The head of the ulna articu- 
 lates with the sigmoid fossa in the lower end of the radius, forming the inferior 
 radio-ulnar articulation. 
 
 The Humerus. (Fig. 129.) 
 
 Locate, classify, and describe geometrically the humerus. 
 
 It is the arm bone, located between the shoulder and elbow, and long by clas- 
 sification. It has an outer, an inner, and a posterior surface. It has an anterior, 
 an external, and an internal border. It has a superior extremity or upper one- 
 third ; an inferior extremity or lower one-third ; a middle one-third. 
 
 Name the bony parts of the Jnimerus concerned in practical anatomy, and give 
 their practical importance. 
 
 The head of the humerus articulates with the head of the scapula. 
 
 The anatomical neck gives attachment to the capsule. 
 
 The surgical neck is very often the seat of fracture. 
 
 The bicipital groove lodges the long head of biceps muscle. 
 
 The bicipital lips surmount and deepen the bicipital groove. 
 
 The greater tuberosity gives tendinous insertion to three muscles. 
 
 The lesser tuberosity gives tendinous insertion to one muscle. 
 
 The internal condyle is developed by traction of flexors and pronators. 
 
 The internal condylar ridge has the internal intermuscular septum. 
 
 The external condyle is developed by extensors and supinators. 
 
 The external condylar ridge has the external intermuscular septum. 
 
 The capitellum articulates with the concave surface of the radius. 
 
 The trochlea articulates with the greater sigmoid of the ulna. 
 
 The coronoid fossa is produced mechanically by the coronoid process. 
 
 The olecranon fossa is produced mechanically by the olecranon process. 
 
 The radial depression is produced by the head of the radius. 
 
 Name the muscles inserted into the greater tuberosity of the liumerus. 
 
 The supraspinatus into the upper facet ; the infraspinatus into the middle 
 facet ; the teres minor into the lower facet. 
 
 HOT.V is the lesser tuberosity occupied f 
 
 By the tendinous insertion of the subscapularis muscle. It has one facet only. 
 
 Where is the transverse hum era/ ligament and what is its function f 
 
 It extends from the greater to the lesser tuberosity of the humerus, convert- 
 ing the bicipital groove into a canal for the lodgment of the long or scapular head 
 of the biceps muscle. 
 
 Hoiv would you locate the surgical neck of the humerus f 
 
 It is the constricted portion of the bone below the tuberosities. It is the 
 portion of the humerus most frequently fractured in the upper one-third. 
 
 H&iv do the three fossa of the liumerus, in the vicinity of the elbow enhance the 
 gravity of a fracture passing through them f 
 
SHOULDER, ARM, FOREARM, AND HAND. 171 
 
 They may become filled with provisional callus and bone, when a stiff joint 
 will be the result. 
 
 Hoiv is the posterior surface of the humcrus occupied / 
 
 By the long humeral head of the triceps above the musculo-spiral groove ; 
 by the short humeral head below the groove ; by the musculo-spiral groove, in 
 which are the musculo-spiral nerve and superior profunda artery. 
 
 How is the outer lip of the bicipital groove occupied ? 
 
 By the tendinous insertion of the pectoralis major muscle. 
 
 How are the outer and inner surfaces of tlic Juuneriis occupied ? 
 
 They are occupied by the pectoralis major, deltoid, and brachialis anticu 
 on the outer ; the teres major, latissimus dorsi, coraco-brachialis, and brachialis 
 anticus on the inner surface. 
 
 How is the external condylar ridge occupied ? 
 
 By the supinator longus and the extensor carpi radialis longior ; the former 
 occupies the upper two-thirds, the latter the lower one-third of the ridge. 
 
 Name all the muscles attached to the middle one-third of the Jiuinerus wliose 
 action would tend to displace the fragments in case of fracture in this locality. 
 
 The long and short humeral heads of the triceps, the deltoid, the coraco- 
 brachialis, the brachialis anticus muscles. 
 
 What might be the most serious complication of 'a fracture in the middle one- 
 tJiird of the liumerus? 
 
 Compression and paralysis of the musculo-spiral nerve, in which there would 
 be inability to extend the carpus and digits and to supinate the radius. 
 
 What is the direction taken by the nutrient foramen of the humcrus ? 
 
 It conforms to the rule governing the direction of these foramina in the long 
 bones of the extremities : to the elbow and from the knee being the rule. 
 
 Hoiv many muscles and ligaments are attached to the humerus ? 
 
 There are twenty-five muscles and eight ligaments attached. 
 
 In this region you will find the following arrangement of 
 
 Muscles Physiologically Grouped. 
 
 Carpal Flexors. Flexor carpi radialis. 
 
 Flexor carpi ulnaris. 
 
 Palmaris longus. 
 Digital Flexors. Flexor sublimis digitorum. 
 
 Flexor profundus digitorum. 
 
 Flexor longus pollicis. 
 Radial Pronators. Pronator radii teres. 
 
 Pronator radii quadratus. 
 Forearm Flexors. Flexor biceps cubiti. 
 
 Flexor cubiti brachialis anticus. 
 
 Flexor brachio-radialis. 
 Nerves. Median nerve and its branches. 
 
 Ulnar nerve and its branches. 
 
 Musculo-cutaneous nerve and its branches. 
 Arteries and Veins. Radial artery and the deep palmar arch. 
 
 Ulnar artery and the superficial palmar arch. 
 
 Common interosseous artery and vein. 
 
 Anterior interosseous artery and vein. 
 
 Posterior interosseous artery and vein. 
 Surgical Areas. The cubital fossa and its contents. 
 
 The radial groove and its contents. 
 
 The ulnar groove and its contents. 
 
172 PRACTICAL ANATOMY. 
 
 The cubital fossa has geometrically a 
 
 1. Roof, formed by the skin and fasciae superficial and deep. 
 
 2. Floor, formed by the brachialis anticus and supinator brevis. 
 
 3. Superior border, formed by an imaginary line from condyle to condyle. 
 
 4. Outer border, formed by the brachio-radialis muscle. 
 
 5. Inner border farmed the pronator radii teres muscle. 
 
 Inferior profunda artery 
 A iiastoiiio/icft magna artery 
 
 Braehiul artery 
 Radial recurrent artery . 
 
 Supinator longus 
 Radial artery. 
 
 Flexor longus pollicis muscle 
 
 
 Brachialia anticus muscle 
 
 Aiili-rior nhiiir rri'iirrenl 
 ' Posterior ulnar recurrent 
 
 -Ulnar artery 
 
 Anterior interosseous artery 
 Flexor carpi ulnaris 
 
 Flexor profundus digitorum muscle 
 Anterior interosseous artery 
 
 Anterior annular ligament, out - 
 
 Anterior branch of ulnar artery, cut 
 Deep pal mar arch 
 
 Palmar interosseous arteries 
 Palmar digital artery, oil short 
 
 Collateral branch of palmar digital artery 
 
 J 
 
 FIG. 117. TIIK AKTKRIKS OK Tin; FoRKAR] 
 
 ii MIK DKKI- P.M. MAR ARCH. 
 
 The fossa contains the following structures 
 
 (i) The brachial artery and veins ; (2) the radial artery ; (3) the ulnar artery ; 
 (4) the tendon of the biceps muscle ; (5) the median nerve ; (6) the musculo- 
 spiral nerve ; (7) the radial recurrent artery ; (8) the ulnar recurrent artery 
 (9) the common interosseous artery. 
 
 The radial groove has these geometrical parts : 
 
SHOULDER, ARM, FOREARM, AND HAND. 173 
 
 1. Roof, formed by skin and fasciae superficial and deep. 
 
 2. Floor, formed by flexor longus pollicis and pronator quadratus. 
 
 3. Outer border, formed by supinator longus or brachio-radialis muscle. 
 
 4. Inner border, formed by the flexor carpi radialis and pronator radii teres. 
 
 5. Contents, consisting of the radial artery and its venae comites. 
 The ulnar groove has these geometrical parts : 
 
 1 . Roof, formed by the skin and fasciae, superficial and deep. 
 
 2. Floor, formed by the flexor profundus digitorum muscle. 
 
 MEDIAN NERVE 
 
 Posterior branch of 
 
 anastomotica magna 
 
 BRANCHES OF ( 
 
 INTERNAL CUTA-J. 
 
 NEOUS NERVE (_ 
 
 Posterior ulnar vein 
 
 Brachialis anticus 
 
 Anterior branch of 
 anastomotica magna 
 Anterior ulnar ruin 
 
 Median basilic vein 
 
 MUSCULAR BRANCH 
 OF MEDIAN NER VE 
 
 Tendon of biceps 
 Bieipital fascia 
 
 Erachialis anticus 
 
 Deep median vein 
 
 Ulnar artery 
 
 Pronator teres 
 
 Radial artery 
 
 Biceps 
 
 Internal vena 
 comes of 
 brachial artery 
 Basilic vein 
 
 Brachialis 
 anticus 
 
 Cephalic vein 
 
 Brachial artery 
 EXTERNAL 
 
 CUTANEOUS 
 
 NER VE 
 Musculo-spiral 
 n. and ascending 
 branch of radial 
 recurrent artery 
 Radial vein 
 Median cephalic 
 
 vein 
 
 Ascending br. of 
 radial recurrent 
 RADIAL 
 
 NERVE 
 Radial recurrent 
 
 artery 
 Supinator 
 ' longus 
 
 Descending br. 
 
 of radial 
 
 recurrent 
 Median vein 
 
 RADIAL 
 NERVE 
 
 FIG. 118. THE BEND OF THE EI.HUW WITH THE SUPERFICIAL VEINS. 
 (From a dissection by Dr. Alder Smith in the Museum of St. Bartholomew's Hospital.) 
 
 3. Outer border, formed by the flexor sublimis digitorum muscle. 
 
 4. Inner border, formed by the flexor carpi ulnaris muscle. 
 
 5. Contents, which are : ulnar artery, vena? comites, and ulnar nerve. 
 Dissection (Fig. 117). The Radial Artery. Cut through the roof of the 
 
 groove. Then, with your scissors and forceps or director, follow the artery up 
 to the bifurcation of tlic brachial artery. Observe the numerous small muscular 
 branches that are given off by this artery both to muscles and skin. 
 
 The Ulnar Artery. Cut through the roof of its groove and follow it up as 
 far as you can without cutting into the flexor sublimis digitorum muscle. Note 
 
174 
 
 PRACTICAL ANATOMY. 
 
 the presence of the ulnar nerve on its inner or ulnar side. Find also where this 
 nerve gives off its dorsal ulnar cutaneous branch, to be distributed to the dorsum 
 of the little finger and half of the ring finger. 
 
 The Cubital Fossa. Figure 1 18 shows the superficial dissection of this area 
 you have already made. Now cut the bicipital fascia with scissors, and develop 
 the brachial artery and its branches, and make your dissection look like figure 
 1 19. Note (i) the brachial artery ; (2) to the inner side of this artery the median 
 nerve; (3) to the outer side of the artery the tendon of the biceps muscle; 
 (4) to the outer side of the tendon of the biceps, see the musculo-spiral nerve, 
 deeply located between the brachialis anticus muscle and the supinator longus 
 muscle, dividing into the radial and posterior interosseous nerves. Find also 
 
 POSTERIOR BRANCH 
 
 OF INTERNAL 
 
 CUTANEO US NER VE 
 ANTERIOR BRANCH 
 
 OF INTERNAL 
 
 CUTANEOUS NERVE 
 
 Brachial artery 
 
 BRANCH TO 
 PRONATOR TERES 
 
 Bicipital fascia, cut 
 
 Pronator radii tercs 
 muscle 
 
 MEDIAN NERVE 
 
 Ulnar artery 
 
 Biceps muscle 
 
 BRANCH OF MUSCULO- 
 SPIRA L NER VE TO 
 SUPINA TOR LONG US 
 
 RADIAL NERVE 
 
 Radial recurrent artery 
 ,i>,,l POSTERIOR 
 INTEROSSEO US 
 NERVK 
 
 Tendon of biceps 
 
 MUSCUL O- CUTA NEO US 
 NERVE 
 
 ' Supinator longus muscle 
 
 j Radial artery 
 
 FIG. 119. THE BKACHIAI. ARTERY AT TIN I'.KND OK THE Ku;\v. 
 
 the muscular branches to the pronator radii tores and supinator longus muscles, 
 from the median and musculo-spiral nerves respectively. 
 
 Carefully remove the deep fascia from the muscles and your dissection of the 
 cubital fossa will look like figure I 20. You will now find each tendon individual;}-, 
 as in figure 120, near the annular ligament; trace it up to the muscular mass 
 from which it comes ; then refer to the figure for the name of the structure. 
 Caution : As you thus in cleaning the muscles one by one remove the deep fasc ia 
 from the muscles, do not destroy the superficial vessels and nerves divide only 
 the connective tissue-. 
 
 For convenience of dissection develop the muscles of first group (Fig. 120): 
 I. Pronator radii tcrcs : origin, inner comlyle and coronoid process. 
 
SHOULDER, ARM, FOREARM, AND HAND. 175 
 
 2. Paliuaris longns ; origin, inner condyle by the common tendon. 
 
 3. Flexor carpi radialis ; origin, inner condyle by the common tendon. 
 
 4. Flexor carpi ulnaris; origin, inner condyle and olecranon. The flexor carpi 
 ulnaris has two heads, with the ulnar nerve between them. This muscle also 
 
 Triceps 
 
 Brachialis antieus 
 
 Pronator radii tares 
 
 Flexor carpi radialis 
 
 Palraaris longus 
 
 Flexor carpi ulnaris 
 
 sublimia digitorum 
 
 Biceps 
 
 Brachio-radialis 
 
 Flexor longus pollioia 
 
 FIG. 120. FRONT OF THE FOREARM: FIRST LAYER OF MUSCLES. 
 
 forms one of the boundaries for the ulnar groove. Notice carefully the extensive 
 insertion of the flexor carpi ulnaris muscle into (i) the pisiform bone, (2) the 
 unciform bone, (3) the anterior annular ligament, (4) the base of the fifth meta- 
 carpal bone. 
 
i 7 6 
 
 PRACTICAL ANATOMY. 
 
 The flexor carpi radialis muscle (Fig. 120) is seldom properly dissected by 
 the student to its specific insertion. Trace its tendon through two canals, and to 
 two bones for insertion ; one canal is on the outer side of the annular ligament, 
 the other is in the bone at the base of the thumb the OS trapezium. The 
 muscle is inserted into the bases of the second and third metacarpals. 
 
 lo 
 
 FIG. 121. SUPERFICIAL MUSCLES OK PALMAR Asn-.i i i FOKKAKM. 
 
 I. Lower portion of biceps. 2. Bicipital fascia. 3. Tendon of insertion into radius. 4, 4. Brachialis 
 aniicus. 5. Internal head of triceps 6. Pronator radii teres. 7. Flexor carpi radialis. 8. Pal- 
 maris longus. 9. Its termination in palmar ligament. 10. Flexor carpi ulnaris. II. Its attachment 
 to pisiform hone. 12. Supinator longus. 13. Its attachment to styloid process of radius. 14, 14. 
 Extensor carpi radialis longior. 15. Extensor carpi radialis brevior. 16. Extensor ossis metacarpi 
 pollicis. 17. Its tendon of insertion into base of first metacarpal hone. 18. Tendon of extensor 
 secuncli internody pollicis. 19, 19. Flexor suhlimis dighorum. 20, 2O. Tendons of this muscle. 
 21, 21. Their attachment to second phalanges of fingers. 22, 22. Attachment of tendons of flexor 
 profundus digitorum to last phalanges of lingers. 23, 23. Lumhricales. 24. Abductor pollicis. 
 25. Its insertion into fir.^t phalanx of thumb. 26, 26. Flexor longus pollicis. 27. Flexor brevis 
 minimi digiti. 28. Abductor minimi digiti. 
 
 The palmaris longus muscle is properly a tensor of the palmar fascia. The 
 muscle is inserted into the annular ligament and also into the palmar fascia. It 
 is often absent. It is a decided flexor of the carpus. 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 177 
 
 The pronator radii teres muscle must first be separated from the flexor carpi 
 radialis, by dividing the connective tissue with scissors and forceps. Next pull 
 the brachio-radialis outward, and expose the insertion of the pronator radii teres 
 into the middle third of the outer surface of the radial shaft. Now trace the 
 
 Biceps 
 Triceps 
 
 Muscles of first layer 
 Brachialis anticus 
 
 Flexor sublimis digitorum L~ 
 
 Flexor carpi ulnaris 
 
 Plexor carpi radialis 
 Falmaris longus 
 
 Brachio-radialis 
 
 Extensor carpi radialis iongior 
 
 Supinator brevis 
 
 Brachio-radialia 
 Flexor longus pollicis 
 
 Extensor ossis metacarpi pollicis 
 Extensor brevis pollicis 
 
 FIG. 122. FRONT OF THE FOREARM: SECOND LAYER OF MUSCLES. 
 
 median nerve down, and see it pass between the two heads of the pronator radii 
 
 teres, to reach the under surface of the flexor sublimis digitorum. (Fig. 119.) 
 
 The ulnar artery's course (Fig. 117) to reach its groove as described on 
 
 page 172 ; Cut the origins at the internal condyle, of the pronator radii teres, 
 
i 7 8 
 
 PRACTICAL ANATOMY. 
 
 BRACIHAL PLEXUS 
 
 HEAD OF HUMERUS 
 Fectoralis minor, turned back 
 
 MUSCULO-CUTANEOUS NERVE 
 BRANCH OF MUSCULO-CUTA- 
 NEOUS TO MEDIAN NERVE 
 Coraco-brachialis 
 
 Brachial artery 
 
 Superior profunda artery 
 Biceps 
 
 MUSCULO-CUTANEOUS NERVE 
 
 BRANCH OF MUSCULO-CUTA- 
 NEOUS NERVE TO BRACHI- 
 ALIS ANTICUS 
 
 Brachialis anticua 
 MEDIAN NERVE 
 
 Inner brachial vena comes 
 MUSCULO-SPIRAL NERVE 
 
 Radial recurrent artery 
 Supinator longus 
 
 Superficial median vein, cut short 
 
 Fronator radii teres, superficial 
 head, cut 
 
 RADIAL NERVE . 
 
 Radial artery 
 
 Cut edge of flexor sublimis 
 digitorum 
 
 MEDIAN NERVE 
 
 Flexor lougua pollioiB 
 
 Subacapularis 
 Acromio-thoracic artery 
 Axillary <nier>/ 
 MEDIAN NERVE 
 Subscapular artery 
 
 Teres major 
 Latissimus dorsi 
 
 Long head of triceps 
 MUSCULO-SPIRAL NERVE 
 
 ) MUSCULAR BRANCH OF 
 }- M I -SCULO-SPIRA L 
 ) NER VE 
 
 R i Inferior profunda artery 
 
 Inner head of triceps 
 ULNAR NERVE 
 
 Anaslomotica magna artery 
 Internal intermuscular septum 
 
 MUSCULAR BRANCHES OF 
 MEDIAN NERVE 
 
 Pronator teres and superficial 
 flexor muscles, turned back 
 
 Anterior ulnar recurrent artery 
 
 Deep head of pronator radii 
 teres 
 
 Posterior ulnar recurrent artery 
 
 Superficial flexor muscles, 
 turned back 
 
 Anterior inlerosseons artery and nerve 
 Flexor profundus digitorum 
 ULNAR NER VE 
 
 Ulnar artery 
 
 Interosseous membrane with cut edge 
 of pronator quadratus 
 
 FIG. 123. THE LOWKK PART OK TIIK AXII.I.AKY, TIIK P,R.\rm.\i.. AND THK RADIAI, 
 
 AND ULNAR AKTKKIKS. 
 (From a dissection in the Hmiterian Museum.) 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 179 
 
 the flexor carpi radialis, the palmaris longus, flexor sublimis digitorum, and turn 
 them aside, but do not injure the nerves and vessels to the same. Find the 
 ulnar artery, and you will see it passes behind all these three muscles. Now 
 trace it a little further, and see it pass behind the flexor sublimis digitorum and 
 median nerve. Here you will find it has reached the ulnar groove. Remem- 
 
 Capsular ligament 
 Internal lateral ligament 
 
 Tubercle for the flexor sublimis 
 
 digitorum 
 Internal lateral ligament 
 
 Brachialis auticus 
 Pronator radii teres (lesser head) 
 
 Flexor longus pollicis (accessory head) 
 
 ULNA 
 
 Interosseous membrane 
 
 Flexor profundus digitorum 
 
 Pronator quadratus 
 
 Anterior radio-ulnar ligament 
 Internal lateral ligament 
 
 GREATER SIGMOIO FOSSA 
 
 HEAD OF RADIUS 
 NECK OF RADIUS 
 Lower limit of orbicular ligament 
 
 Oblique ligament 
 
 BICIPITAL TUBERCLE 
 
 Oblique ligament 
 Supinator brevia 
 
 Flexor sublimis digitorum 
 
 OBLIQUE LINE 
 
 RADIUS 
 
 Prouator radii teres 
 
 flexor longus pollicis 
 
 Pronator quadratus 
 
 Supinator longus 
 External lateral ligament 
 
 Interarticular flbro-cartilage Anterior radio-carpal ligament 
 
 FIG. 124. THE LEFT ULNA AND RADIUS. (Antero-internal view.) 
 
 ber the course : behind the median nerve and all the muscles originating from 
 the inner condyle, except the flexor carpi ulnaris. 
 
 The radial' s course (Fig. 117): You will find it very superficial. It begins 
 at the bifurcation of the brachial artery in the cubital fossa. Now demonstrate 
 the fact that this artery lies on : (i) Biceps tendon ; (2) supinator brevis ; (3) 
 flexor sublimis digitorum ; (4) pronator radii teres ; (5) flexor longus hallucis ; (6) 
 pronator quadratus. These structures form the floor of the radial groove. 
 
 The flexor sublimis digitorum (Fig. 122) is brought into view by turning 
 
i8o 
 
 PR A CTICAL ANA TO MY. 
 
 the above muscles well aside. You will see the radial artery lying on its outer 
 part ; the ulnar artery and median nerve above, passing behind the arch connect- 
 ing the two heads of the flexor sublimis digitorum muscle. This muscle has three 
 heads: (i) A condylar, arising from the inner condyle of the humerus ; (2) a 
 
 Bleep 
 
 Muscles of the first and second 
 layers 
 
 Flexor profundus digitorum 
 
 Pronator quadratus 
 
 Flexor carpi ulnaris 
 
 Brachio-radialis 
 
 Brachialis anticus 
 
 Extensor carpi radialis longior 
 
 Supinator brevis 
 
 
 flexor longus pollicis 
 
 Brachio-radialis 
 
 Extensor ossis metasarpi pollicis 
 
 Extensor brevis pollicis 
 
 FIG. 125. FRONT OK TIIK FOREARM: THIRD LAYER OF MUSCLES. 
 
 coronoid, from the coronoid process of the ulna ; (3) a radial head, from the 
 oblique line of the radius. (Fig. 124.) Cut the radial origin, and turn the 
 muscle toward the ulna, without injury to the radial artery, and see: (i) The 
 median perve, on the under surface of the muscle; (2) the insertion of the 
 brachialis anticus muscle into the base of the coronoid process of the ulna; (3) 
 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 181 
 
 the origin of the flexor longus pollicis muscle ; (4) the origin of the flexor pro- 
 fundus digitorum ; (5) the anterior interosseous artery and nerve on the inter- 
 osseous membrane, but lying deeply between two muscles the flexor profundus 
 digitorum and the flexor longus pollicis. 
 
 The Median Nerve and its Branches. Take the nerve up, and you can 
 easily trace muscular branches with the forceps to all the muscles on the front 
 
 Pectoralis minor 
 
 Coraco-brachialis 
 
 Long head of triceps 
 
 Inner head of triceps 
 
 Brachialis anticua 
 
 Semilunar fascia 
 
 Tendons of insertion of pec- 
 toralis major and deltoid 
 
 Outer head ct triceps 
 
 - Brachialis anticua 
 
 Extensor carpi radialis 
 longior 
 
 Brachi o -rad i alis 
 
 FIG. 126. SUPERFICIAL VIEW OK THE FRONT OK THE UPPER ARM. 
 
 part of the forearm except the flexor carpi ulnaris and half of the flexor profundus 
 digitorum muscles ; the flexor carpi ulnaris and the ulnar half of the flexor 
 profundus digitorum muscles are supplied by the ulnar nerve. You will observe 
 that some of the branches of this nerve are given off above the articulation. 
 (Fig. 123.) Remember, the shape of a muscle is an index to nerve distribution. 
 See introductory chapter. 
 
182 
 
 PR A CTICAL ANA TO MY. 
 
 The ulnar nerve (Fig. 123) you have already seen in the ulnar groove with 
 its accompanying artery and venae comites. Now see how it gains this groove. 
 Trace it behind the inner condyle, between the condylar and olecranon heads of 
 the flexor carpi ulnaris muscle. Trace its branches to this muscle and to the 
 ulnar half of the flexor profundus digitorum. ' 
 
 The following muscles remain to be dissected (Fig. 125) : 
 
 i. The flexor profundus digitontin, on the ulnar side. 
 
 Pectoralis min 
 
 Short head of bice 
 
 Coraco-brachialis 
 
 Long head of triceps 
 
 Long head of bicer 
 
 ^3 Insertion of pectoralis major 
 
 Inner head of triceps 
 
 Internal-intermuecular septum 
 
 Brachialis anticus 
 
 S&ML Outer part of brachialis anticug 
 
 Insertion oi biceps 
 
 FIG. 127. I)KKi' VIK\V OF run FRONT 01-- TIIK I'ITKK ARM. 
 
 2. The flexor longus po/licis, on the radial side. 
 
 3. The pronator radii quadrat us. 
 
 4. The sjtpinator radii brcris. 
 
 You are expected to dissect these muscles and study critically their specific 
 attachments to bone, and make your dissection tally with the origins as indicated 
 on the hones in figure 124. 
 
 The flexor profundus digitorum is seldom well learned, because students 
 
SHOULDER, AR.\f, FOREARM, AND HAND. 
 
 183 
 
 forget its aponeurotic origin. The muscle originates (i) from the anterior sur- 
 face, upper two-thirds of the ulna ; (2) from the upper three-fourths of the 
 posterior border of the ulna, with the flexor carpi ulnaris and extensor carpi 
 ulnaris muscles. This latter is called the aponeurotic origin. Trace nerves to 
 this muscle from the median and ulnar. 
 
 FIG. 128. DEEP MUSCLES OF PALMAR ASPECT OF FOREARM. 
 
 Lower portion of triceps. 2, 2. Attachments of pronator radii teres. 3. Attachment of flexor carpi 
 radialis, palmaris longus, and flexor sublimis digitorum. 3' '. Tendon of biceps. 3" '. Tendon of 
 brachialis anticus. 4, 4. Flexor carpi ulnaris. 5. Supinator longus. 6. Its distal attachment. 7. 
 Supinator brevis. 7'. Extensor carpi radialis longior. 8, 8. Extensor ossis metacarpi pollicis. 9. 
 Flexor profundus digitorum. 10. Its four tendons. II. Tendon for index finger. 12, 12. Tendon 
 for middle finger. 13. Tendon of flexor sublimis. 14. Tendon of flexor profundus for little finger. 
 15, 15. Lumbricales. 16, 16. Attachments of abductor brevis. 17. Opponens pollicis. 18. Flexor 
 brevis pollicis. 19. Adductor pollicis. 20. Flexor longus pollicis. 21. Its tendon. 22, 22. 
 Attachments of flexor brevis and adductor minimi digiti. 23. Opponens minimi digiti. 
 
 Detach the extreme upper origin of this muscle and study (i) the insertion 
 of the brachialis anticus ; (2) the lesser or coronoid head of the pronator radii 
 teres ; (3) the accessory head of the flexor longus pollicis ; (4) the coronoid origin 
 of the flexor sublimis digitorum. 
 
1 84 
 
 PRACTICAL ANATOMY. 
 
 The Pronator Quadratus. Observe the anterior interosseous nerve termin- 
 ating in this muscle. Detach the muscle from its ulnar origin, turn the same aside, 
 and see the anterior interosseous artery piercing the membrane and gaining the 
 posterior surface ; also see the anastomosis between a branch of this artery and 
 the anterior carpals. 
 
 HEAD 
 
 LESSER TUBEROSITY 
 Subscapularis 
 
 Capsular ligament 
 
 Coraco-brachialis brevis 
 (Rotator burner!) 
 
 BICIPITAL GROOVE 
 
 GREATER TUBEROSITY 
 
 Transverse humeral ligament 
 
 Fourth head of biceps 
 
 Coraoo-brachialis 
 
 Third head of bicepe 
 
 Braehialis anticus 
 
 Coraco-brachialis 
 
 SUPRACONDYLOID PROCESS 
 
 Pronator radii teres 
 
 Capsular ligament 
 CORONUID FOSSA 
 
 INTERNAL CONDYLE 
 Internal lateral ligament 
 
 TROCHLEA 
 
 ROUGH SURFACE FOR deltoid 
 
 THE EXTERNAL CONDYLAR RIDGE 
 
 RADIAL DEPRESSION 
 
 EXTERNAL CONDYLE 
 CAPITELLUM 
 
 FIG. 129. THK LEFT HU.MKKI s \\nii A SITK \OI\I>YI,<III) PROCESS AND SOME IRREGUI \K 
 MUSCLE ATTACHMENTS. (Anterior view.) 
 
 The Flexor Longus Pollicis (Fig. 124). Notice and demonstrate on your 
 dissection that the origin of this muscle is limited above by the tuberosity and 
 oblique line of the radius ; that the lower part of the same is limited by the 
 pronator quadratus, the inner by the interosseous membrane. Trace this muscle 
 
 
SHOULDER, ARM, FOREARM, AND HAND. 185 
 
 under the anterior annular ligament, and between the two heads of the flexor brevis 
 pollicis, to the base of the distal phalanx of the thumb, where it is tendinously 
 inserted. 
 
 You are to study the radial oblique line, and let your dissections show 
 the following points : 
 
 1. It terminates above in the bicipital tuberosity, and into this tuberosity is 
 inserted the tendon of the biceps muscle. 
 
 2. It terminates below in a round depression, and into this is inserted the 
 pronator radii teres muscle. (Fig. 128.) 
 
 3. It has three lips : an outer, into which is inserted the supinator brevis 
 muscle ; a middle lip, that gives origin to the radial head of the flexor sublimis 
 digitorum, and location to the nutrient foramen of the radius ; an inner lip, that 
 gives origin to the flexor longus pollicis. (Fig. 124.) 
 
 THE FOREARM FLEXORS. 
 
 In the order of their strength they are as follows : 
 
 1 . The musculus biceps cubiti or biceps muscle. 
 
 2. The musculus bracliio-radialis or supinator longus muscle. 
 
 3. The musculus bracJdalis anticus very broad and fleshy. 
 Dissect and study the biceps with reference to : 
 
 1. Its origin by a coracoid or short, and a scapular or long head. 
 
 2. Its insertion by a tendon and by an aponeurosis. 
 
 3. Its fusiform belly and the rule for the nerve-supply of muscles. 
 
 4. Its inferior, external, and internal relations. 
 
 5. Its synergists and antagonists, and nerve-supply. 
 
 6. Its limiting intermuscular fasciae. 
 
 7. Its fibrous arch and the rule for fibrous arches. 
 
 The biceps (Fig. 126) you have found inserted aponeurotically, by the bicip- 
 ital or semilunar fascia, into the deep fascia, over the pronator radii teres muscle. 
 It is tendinously inserted into the bicipital tuberosity of the radius. It arises 
 by two heads, called long and short. The long head arises from the bicipital 
 tubercle, above the glenoid cavity of the scapula; it passes under the transverse 
 humeral ligament of the shoulder, between the greater and lesser tuberosities of 
 the humerus, in the bicipital groove. The short head you will find arising from 
 the apex of the coracoid process of the scapula, with the coraco-brachial muscle. 
 These two heads of the biceps are connected by a fibrous arch. See rule for 
 fibrous arches in the introductory chapter. The biceps muscle rests on the brachi- 
 alis anticus muscle. Under the biceps muscle you will find the musculo-cuta- 
 neous nerve which supplies it and also the brachialis anticus, coraco-brachial, 
 and supinator longus muscles. Externally are the deltoid and triceps and 
 pectoralis major. Internally are the triceps, the latissimus dorsi, teres major, and 
 coraco-brachial muscles. Lift the biceps from its bed, pull the same outward, 
 and you will expose the brachialis anticus muscle below. In the groove, between 
 the triceps and the inner part of the biceps, are to be found the large branches of 
 the brachial plexus and the brachial artery and its venae comites. 
 
 The brachio-radialis or supinator longus muscle (Fig. 128) arises from the 
 upper two-thirds of the outer condylar ridge of the humerus. (Fig. 129.) It is 
 inserted into the base of the radial styloid process. It has the double function of 
 flexion and supination. Trace to it nerves from the flexor trunk, the musculo- 
 cutaneous, and from the extensor trunk, the musculo-spiral. 
 
 The brachialis anticus (Fig. 127) arises from the outer and inner surfaces of 
 the humerus, limited above by the insertion of the deltoid and coraco-brachial 
 muscles. (Fig. 129.) Its insertion you have already seen into the coracoid pro- 
 
1 86 PRACTICAL ANATOMY. 
 
 cess of the ulna. Its nerve-supply comes from the musculo-cutaneous. This 
 muscle and the preceding one act synergistically' with the biceps as flexors of 
 the forearm ; they are all three antagonized by the triceps. 
 
 The middle one-third of the humerus (Fig. 1 29) shows the following muscles 
 exerting traction: (i) The brachialis anticus ; (2) the deltoid; (3) the coraco- 
 brachial ; (4) the upper and lower humeral heads of the triceps, on the posterior 
 surface. 
 
 The capsule of the elbow may now be studied. Remove the insertions of 
 the biceps and brachialis anticus, and expose and cut through the anterior liga- 
 ment of the elbow-joint. 
 
 THE ANTERIOR REGION OF THE SHOULDER. 
 
 Dissection of this region must be preceded by a review of its osteology. 
 Remember, the surgical importance of the shoulder-joint is second to none. 
 
 The Scapula. 
 
 Locate, classify, and describe geometrically this done. 
 
 It is located on the upper, posterior, and outer aspect of the thorax, limited 
 above by the second and below by the seventh rib. It is a flat bone. It has a 
 dorsal, or posterior, and a ventral, or anterior, surface. It has superior, axillary, 
 and vertebral borders ; an anterior, a posterior superior, and a posterior inferior 
 angle. It has a spine, a coracoid, and an acromion process. 
 
 Give the importance of the following parts of the scapula in practical anatomy : 
 
 The anterior angle, or head, articulates with the humerus. 
 
 The anatomical neck gives attachment to the capsular ligament. 
 
 The surgical neck is often the seat of fracture. 
 
 The spine divides the dorsum into supra- and infraspinous fossae. 
 
 The posterior inferior angle is crossed by the latissimus dorsi muscle. 
 
 The supraspinous fossa is occupied by the supraspinatus muscle. 
 
 The infraspinous fossa is occupied by the infraspinous muscle. 
 
 The subscapular fossa is occupied by the subscapularis muscle. 
 
 The superior border has the suprascapular foramen and omo-hyoid muscl 
 
 The suprascapular foramen transmits the suprascapular nerve. 
 
 The coracoid process gives attachment to three muscles and three ligaments. 
 
 The acromion process gives attachment to the trapezius and deltoid. 
 
 The scapular notch transmits the infraspinous vessels and nerve. 
 
 The scapular angle is the deepest part of the subscapular fossa. 
 
 Name the muscles and ligaments you arc expected to find attaclicd to tJic cora- 
 coid process of the scapula. 
 
 The short head of the biceps, the coraco-brachialis, and the pectoralis minor 
 muscles ; the coraco-acromial, conoid, and trapezokl ligaments. 
 
 The supra- and infraglcnoid tubercles arc where situated and liow occupied / 
 
 They arc immediately above and below the glenoid cavity of the scapular 
 head respectively : the supraglenoid tubercle gives origin to the long head of the 
 biceps ; the infraglenoid to the long head of the triceps muscle. 
 
 II 'hat can YOU say specifically about flic origins of the tlircc muscles from tlic 
 t/ircc scapular fossce ? 
 
 The whole of the fossa in each case does not give origin to the muscle, only 
 tin- outer two-thirds thereof. The one-third next the shoulder is occupied by 
 fatty connective tissue, vessels, and nerves. 
 
SHOULDER, ARM, FOREARM, AND HAND. 187 
 
 Name the muscles attaclicd to tlie middle lip of the axillary border of the 
 scapula. 
 
 The triceps, teres minor, and teres major. The rule governing the relation 
 of anatomical minors to majors is : minors occupy a high, majors a low, level. 
 
 Name the bony points of t/ie scapula traversed by a fracture of the so-called 
 surgical neck of the scapula, and the important structures endangered by sucli a 
 fracture. 
 
 The suprascapular notch, in which is the suprascapular nerve, and above 
 which are the suprascapular vessels ; the scapular notch, in which are found the 
 vessels and nerves for the infraspinatus muscle ; the scapular angle, in which are 
 the vessels and nerves for the subscapularis muscle. 
 
 Hoiv is the anterior lip of the vertebral border of the scapula occupied ? 
 
 By the subscapularis and serratus magnus muscles. The latter muscle de- 
 presses the shoulder-girdle, being antagonistic to the trapezius and levator anguli 
 scapulae muscles. 
 
 Name the muscles inserted into t/ie middle lip of the vertebral border of the 
 scapula. 
 
 The levator anguli scapulae, rhomboideus minor, rhomboideus major. Notice 
 here the high origin of the minor, and note the rule previously mentioned 
 governing the relation of anatomical majors and minors. 
 
 How are the three lips of the spine of the scapula occupied ? 
 
 The superior by the insertion of a part of the trapezius ; the inferior by origin 
 of part of the deltoid ; the middle is subcutaneous, and is also called the crest. 
 
 The Clavicle. 
 
 Name parts of this bone of importance in practical anatomy. 
 
 The sternal end, articulating with the manubrium. 
 
 The acromial end, articulating with the acromion. 
 
 The anterior surface of the inner two-thirds of the bone. 
 
 The superior surface of the outer one-third of the bone. 
 
 The inferior surface of the bone. 
 
 What is the importance of the superior surface of the outer one-third of the 
 clavicle ? 
 
 The attachment of the trapezius muscle posteriorly, and the deltoid anteriorly. 
 
 What is the importance of the anterior surface of the inner two-thirds of the 
 clavicle f 
 
 The origin of the pectoralis major and the sterno-cleido-mastoid muscles. 
 
 What can you say of the posterior surface of the clavicle ? 
 
 It forms an arch over the brachial plexus and subclavian artery and vein. 
 
 Tell what you expect to find on the inferior surface of the clavicle. 
 
 The subclavius muscle, in a groove in the middle one-third ; the origins of 
 the sterno-hyoid and sterno-thyroid muscles, and the impress for the rhomboid 
 or costo-clavicular ligament ; the oblique line for the trapezoid ligament and a 
 small tuberosity for the conoid ligament. 
 
 1. Intermuscular groove between the pectoralis major and deltoid. 
 
 2. The pectoralis major muscle and pectoral fascia. 
 
 3. Suprasternal and supraclavicular nerves. 
 
 4. The cephalic vein and descending branch of acromio-thoracic artery. 
 
 5. The pectoral and deltoid origins on the clavicle. 
 
 6. The perforating branches of the internal mammary artery. 
 
 7. The axillary space geometrically. 
 
i88 
 
 PRACTICAL ANATOMY. 
 
 THE AXILLARY SPACE. 
 
 1. A Base. Skin, superficial, and deep fascia, called axillary. 
 
 2. An Apex. Formed by clavicle, first rib, and scapula. 
 
 3. Anterior Border. Pectorales major and minor, and clavi-pectoral fascia. 
 
 Deltoid 
 
 Biceps 
 
 Teres major 
 
 Aponeurosis of external oblique 
 
 External intercostal 
 
 FK;. 130. THE PECTORAI.IS MAJOR AND DELTOID. 
 
 Deltoid 
 
 Pectoralis major 
 
 Trapezius 
 
 Sterno-maatoid 
 POSTERIOR 
 FH;. 131. THE I.KIT < 'I.AVICI.K. \ Superior surface.) 
 
 4. Interior Border. Ribs, intercostal spaces (six), and serratus magnus. 
 
 5. Anterior Thoracic Angle. Long thoracic artery. 
 
 (>. Interior Thoracic Angle. Subscapular artery and Bell's nerve. 
 
 7. External or Humeral Angle. Axillary artery and nerves. 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 189 
 
 8. Contents. Axillary connective tissue and glands ; the axillary artery 
 and vein and their branches ; the large branches of the brachial plexus. 
 
 9. The posterior boundary is formed by the subscapular, teres major, and latis- 
 simus dorsi muscles. 
 
 The cephalic vein and descending branch of the acromio-thoracic artery. 
 The vein (Fig. 105) is the guide to the groove. The groove is the boundary- 
 line between the clavicular origins of the pectoralis major and deltoid muscles. 
 The vein opens into the subclavian. 
 
 The Pectoralis Major Muscle. Remove the skin and find in the super- 
 ficial fascia two cutaneous nerves the supraclavicular and suprasternal ; the 
 one supplying the skin over the deltoid is the supraacromial. These are the 
 descending branches from the superficial part of the cervical plexus. 
 
 Subclavius muscle 
 
 First Rib 
 
 CUT END OF CLAVICLE 
 
 Costo-coracoid 
 ligament 
 
 Cephalic rein 
 
 . I rroin io-thoraeic artery 
 
 Xti/H-riii 1 ' flinnii-ic ai-ten/ 
 Clavi-pectoral fascia 
 
 l>n*TI-:RIOR THOR- 
 ACIC .VAY.M7-; 
 
 FIG. 132. THE CLAVI-PECTORAL FASCIA. 
 
 The deltoid aponeurosis is the deep fascia covering the muscle of the same 
 name. It is continuous with the pectoral in front, the infraspinous behind, and 
 the axillary below. 
 
 The Deltoid Muscle. Detach this muscle from the clavicle (Fig. 131) and 
 acromion process of the scapula. Turn the muscle outward. Follow the muscle 
 to its insertion into the deltoid ridge, on the outer surface of the humenis. 
 (Fig. 127.) Cut this insertion and turn the muscle farther back, so as to expose 
 the insertion of the pectoralis major. 
 
 The Pectoralis Major. Remove the fascia with a sharp scalpel. Place 
 the arm at a right angle to the body ; notice that the deep fascia you are now 
 
190 
 
 PR A CTICAL ANA TOMY. 
 
 removing is continuous with the deep fascia covering the base of the axilla. 
 Observe the sternal and clavicular origins of the muscle. See some cutaneous 
 nerves and arteries piercing the thoracic wall, near the sternum. (Fig. 132.) The 
 arteries are the perforating branches from the internal mammary ; the nerves are. 
 the anterior cutaneous branches of the intercostals. Cut the insertion of the pec- 
 toralis major. Note that the fibres that form the lower margin of the tendon 
 of the muscle are inserted high ; those that form the upper border of the muscle 
 are inserted low, into the posterior lip of the bicipital groove of the humerus. 
 
 Now cut the clavicular origin of the pectoralis major, and carefully pull the 
 muscle forward. On the under surface you will see the external anterior thoracic 
 nerve, a branch of the outer cord of the brachial plexus, coming through the 
 pectoralis minor muscle to supply the major pectoral muscle. Now cut the 
 sternal origin of the pectoralis major and turn the same out of the way without 
 injuring the nerve -supply. 
 
 above / ^ shove 
 r 7 f&Jai/ 
 / Aeti 
 
 Mylo-hy 
 Old fascii 
 
 Digastric fascia 
 "~^ Submaxillary fascia 
 ~~~ Stylo-mandibular ligament 
 Masseteric fascia 
 Parotid fascia 
 
 
 CUT END OF CLAVICLE 
 
 Subclavius sheath 
 Costo-eoracoid ligament 
 Clavi-pectoral fascia 
 
 Minor pectoral sheath 
 
 - Axillary or suspensory fascia 
 
 FIG. 133. To SHOW SCHEMATICALLY THE DISTRIBUTION OF THE DEEP CERVICAL FASCIA AI;U\I. 
 
 AND BELOW THE CLAVICLE. 
 
 Four very important structures, easily understood, quickly developed, and 
 seldom appreciated by the student, are now before you : 
 
 1. The subclarius muscle and its sheath of cervical fascia. 
 
 2. The costo-coracoid ligament, a part of subclavius sheath. 
 
 3. The clavi- pectoral fascia triangular and thin. 
 
 4. The pectoralis minor muscle and its sheath. 
 
 The third layer of deep cervical fascia passes behind the clavicle, forms a 
 sheath for the subclavius muscle, and unites along the lower margin of the sub- 
 clavius muscle to form a thick, strong band* the costo-coracoid ligament. The 
 fascia then bridges the triangular space between the subclavius muscle and the 
 pectoralis muscle, under the name of clavipectoral fascia. (Fig. 132.) At this 
 point the fascia again delatninates, to form a sheath for the pectoralis minor 
 muscle. At the lower border of this muscle the fascia is continuous with the 
 deep fascia of the base of the axilla, and is known technically as the axillary 
 
SHOULDER, ARM, FOREARM, AND HAND. 
 
 191 
 
 fascia. Let figure 133 illustrate in this connection schematically the distribution 
 of the four layers of deep cervical, both below and above. 
 
 It will be seen from figure 133 that the first layer of deep cervical fascia is 
 specialized above the clavicle as parotid fascia, masseteric fascia, stylo-mandibular 
 ligament, submaxillary fascia, digastric fascia, and mylo-hyoid fascia ; below, the 
 first layer is attached to the clavicle. The second layer is attached above to 
 the hyoid bone, having ensheathed the depressor muscles of this bone (Fig. 24) ; 
 below, this fascia is attached to the clavicle. The fourth layer is connected to 
 the occipital bone and the muscles in front of the vertebral column. 
 
 The third layer is of greatest importance surgically, and the most complex. 
 Passing behind the clavicle and sternum, this layer divides into a thoracic por- 
 tion, which expands to form the fibrous part of the pericardium, and also into an 
 axillary portion, which has been previously described. 
 
 Pus formed between the first and second layers of deep cervical fascia would 
 be arrested at the clavicle. Pus formed in the carotid sheath might easily find 
 its way to either the axilla or pericardium. The student must take schematic 
 representations with a grain of allowance, remembering that fascial development, 
 like muscular development, is a variable thing, and in some cases would not 
 direct pus whither the scheme might indicate. After all, the scheme just 
 
 POSTERIOR 
 
 Oblique 
 
 line for 
 
 Capsular trapezoid Tuberosity for 
 ligament ligament conoid ligament 
 
 Rhomboid 
 ligament and 
 Sterno- 
 hyoid Sterno-thyroid 
 
 FACET FOR FIRST 
 COSTAL CARTILAGE 
 
 STERNAL FACET 
 
 ACROM1AL FACET 
 
 Pectoralis major 
 ANTERIOR 
 
 FIG. 134. THE LEFT CLAVICLE. (Inferior surface.) 
 
 given is to teach that many fascial entities are definitionally only a certain seg- 
 ment of deep cervical fascia. For example : What is the subclavius sheath ? It 
 is that part of the third layer of the deep cervical fascia that invests the sub- 
 clavius muscle. What is the parotid fascia ? It is that part of the first layer of 
 deep cervical fascia which is continued above the angle of the jaw to form a 
 capsule for the parotid gland. See in the introductory chapter the rule for 
 naming specialized modifications of deep fascia in any region of the body. 
 
 The subclavius muscle arises from the first rib, near the sternum, and is in- 
 serted into the groove on the under surface of the clavicle (Fig. 134), occupying 
 the middle two-fourths of the surface. It is surrounded by a sheath the sub- 
 clavian sheath. 
 
 The pectoralis minor muscle arises, as a rule, from the third, fourth, and 
 fifth true ribs, and is inserted into the anterior border of the coracoid process of 
 the scapula. Its nerve is the internal anterior thoracic, a branch of the inner 
 cord of the brachial plexus. 
 
 The clavi-pectoral space is the triangular interval you see between the upper 
 border of 'the pectoralis minor muscle and the subclavian muscle. As you will 
 see on your cadaver, this space is filled in by a delicate fascia, attached above to 
 the subclavius muscle and below to the pectoralis minor muscle. This is the 
 clavi-pectoral fascia. (Fig. 132.) 
 
192 
 
 PRACTICAL ANATOMY. 
 
 THE AXILLA, OR AXILLARY SPACE. 
 
 The axilla, or axillary space, is of interest anatomically because important 
 surgical operations are performed here. Armpit and axilla are not synonymous 
 terms. The physician places a clinical thermometer in the armpit not in the 
 axilla. The axillary lymphatic glands become secondarily enlarged in cases of 
 infection, and may require extirpation. The head of the humerus may become 
 dislocated into the axilla and require reduction. Pus may form in the neck and 
 find its way to the axilla and make its liberation incumbent. A wound of the 
 axillary artery makes its ligation a necessity. Amputation at the shoulder-joint 
 is sometimes done. 
 
 The apex of the axilla or inlet has bony boundaries: (i) The outer surface of 
 the first rib ; (2) the clavicle ; (3) the superior costa or superior border of the scapula. 
 It is by the apex that this space communicates with the thorax and neck. 
 
 Upper part of 
 serratus magnuc 
 
 Middle part 
 
 Lower part 
 
 FIG. 135. SERRATUS MAGNUS. THE INNER \\AI.I OF THE AXII.I.A. 
 
 The base of the axilla is formed by the skin, the superficial and the deep 
 fascia. The deep fascia in this locality is known specifically as axillary fascia ; 
 it is also called suspensory fascia. The deep fascia is a derivative of the third 
 layer of the deep cervical fascia, passing under the clavicle. In front it is con- 
 tinuous with the pectoral fascia; behind, with the fascia covering the latissimus 
 dorsi muscle. 
 
 The anterior boundary is formed by the skin, fascia:, pectorales major and 
 minor muscles, and clavi-pectoral fascia. This boundary is very well defined. 
 
 The posterior boundary is formed by the subscapularis, the teres major, and 
 latissimus dorsi muscles. 
 
SHOULDER, ARM, FOREARM, AND HAND. 193 
 
 The inner boundary is formed by six or eight ribs, their intercostal muscles 
 and fasciae, and six serrations of the serratus magnus muscle. (Fig. 132.) 
 
 The angles are three in number, and the surgical importance of each is that 
 in these angles are found some structure or structures to be avoided, or reached 
 in surgical operations, (i) The anterior thoracic angle contains the long thoracic 
 artery ; (2) the posterior thoracic angle contains the subscapular artery and the 
 external phrenic nerve ; (3) the outer or Innncral angle contains the axillary 
 artery and nearly all the important branches of the brachial plexus. 
 
 The Axillary Contents. On removing the anterior wall of the axilla, as 
 you may now complete doing, by cutting the pectoralis minor at its insertion, and 
 turning the same back, with its attached clavi-pectoral fascia, you will see (i) a 
 mass of axillary connective tissue containing some fat and blood-vessels, the alar 
 thoracic vessels, and axillary lymphatic glands. In health these glands are not 
 larger than a small pea, and are bluish in color. When diseased, as is frequently 
 the case in dissecting-room material, they are often very large ; they may be as 
 
 CLAVICLE 
 
 CORACOIO PROCESS 
 Supra-spinatus 
 
 Subscapularis 
 
 Teres major 
 Latissimus dorsi 
 
 Coraco-brachialis and short 
 head of biceps 
 
 Pectoralis major 
 
 FIG. 136. FRONT VIEW OF THE SCAPULAR MUSCLES. THE POSTERIOR WALL OF THE AXILLA. 
 
 large as a hazelnut, or even larger. Each student should visit every table in the 
 room, when this area is being dissected, to inspect the condition of these glands. 
 
 To clean out the axilla means, in surgery, to remove the diseased axillary 
 glands. This operation is attended by slight hemorrhage. The vessels that 
 should bleed are the alar thoracics. These supply the glands and fat in this 
 space. The term unavoidable hemorrhage would be an excellent expression by 
 which to designate the bleeding incident to the removal of these glands, if this 
 expression were not already the stereotyped property of obstetric nomenclature. 
 
 Systematic Examination of the Walls and Contents of the Axillary Space. 
 i. Examine the inner icall and find: (i) The outer surface of the six upper 
 ribs. (2) The serrations of the serratus magnus muscle. (Fig. 135.) (3) Coming 
 through two or three intercostal spaces, the second, third, fourth, some cuta- 
 neous nerves will be seen. These nerves cross the space and seem to become lost 
 in the mass of fat you have just examined. These nerves are the posterior lateral 
 'cutaneous branches of the intercostal nerves. Now trace them out as follows : 
 One passes out under the pectoralis major muscle to the skin of this muscle, in 
 front ; a second passes out behind, around the latissimus clorsi, to the skin of 
 this muscle ; a third passes down the center of the space, joins a branch of the 
 
i 9 4 
 
 PR A CTICAL ANA TOM Y. 
 
 BRACHIAL PLEXUS 
 
 HEAD OF HUMERUS 
 Fectoralis minor, turned back 
 
 MUSCULO-CUTANEOUS NERVE 
 
 BRANCH OF MUSCULO-CUTA- 
 
 NEOUS TO MEDIAN NERVE 
 
 Coraco-brachialiB 
 
 Brachial artery 
 
 Superior profunda artery 
 Biceps 
 
 MUSCULO-CUTANEOUS NERVE 
 
 URANCH OP MUSCULO-CUTA- 
 NEOVS NERVE TO BRACHI- 
 ALIS ANTICUS 
 
 Brachialis anticus 
 
 MEDIAN NERVE 
 
 Inner brachial vena comes 
 MUSCULO-SPIRAL NERVE 
 
 Radial recurrent artery 
 Supinator loiigus 
 
 Superficial median vein, cut short 
 
 Fronator radii feres, superficial 
 head, cut 
 
 RADIAL NERVE 
 
 Radial artery 
 
 Cut edge of flexor sublimis 
 digitorura 
 
 MEDIAN NER VE 
 
 Flexor lougus polliois 
 
 Subscapularis 
 Acromio-lhoracic artery 
 Axillary artery 
 MEDIAN NERVE 
 Subscapular artery 
 
 Teres major 
 Latissimus dorsi 
 
 Long head of triceps 
 MUSCULO-SPIRAL NERVE 
 
 ) MUSCULAR BRANCH OF 
 \ Ml'KCULO-SPIRAL 
 
 Inferior profunda artery 
 
 Inner head of triceps 
 ULNAR NERVE 
 
 BM Anaslomolica marjna artery 
 
 Internal intermuscular septum 
 
 MUSCULAR BRANCHES OF 
 MEDIAN NERVE 
 
 Pronator teres and superficial 
 flexor muscles, turned back 
 
 A n! 1 rior ulnar recurrent <u i<-rt/ 
 
 Beep head of pronator radii 
 teres 
 
 Posterior ulnar recurrent artery 
 
 Superficial flexor muscles, 
 turned back 
 
 Anterior ititerosxenns artery and nerve 
 Flexor profundus digitorum 
 ULNAR NERVE 
 
 Interosseous membrane with cut edge 
 of pronator quadratus 
 
 IMC. 137. THK I.mvKK PART OF THE AXIIIAKV. ini. HK.U HIM, AMI IHK RADIAL 
 
 AND Ui-NAR AKTKKII-.S. 
 (From a dissection in the Hunterian Museum.) 
 
SHOULDER, ARM, FOREARM, AND HAND. 195 
 
 lesser internal cutaneous nerve (Wrisberg's), and is distributed to the skin of the 
 inner surface of the arm. This nerve is called the intercosto-humeral nerve. It 
 comes through the second intercostal space. 
 
 2. Examine the posterior wall (Fig. 136) and find the (i) subscapularis mus- 
 cle ; (2) teres major muscle ; (3) latissimus dorsi muscle ; (4) the three subscap- 
 ular nerves supplying these muscles. They are branches of the posterior cord 
 of the brachial plexus. 
 
 Notice while dissecting the posterior wall of the axilla the following structures 
 shown in figure 136 : (i) The relation between the insertions of the teres major 
 and latissimus dorsi. Clean off the fascia and fat carefully, and see the lower 
 muscle crossing the higher, to be inserted above this. (2) Trace out and study 
 carefully the specific tendinous insertion of the pectoralis major. (3) Clean the 
 subscapularis muscle, notice its nerve- and blood-supply, and the relation of this 
 muscle to the insertion of the serratus magnus. 
 
 3. Examine the Anterior Thoracic Angle. In this angle you will find the long 
 thoracic or external mammary artery. Trace its branches to the pectoral muscles, 
 the serratus magnus, the subscapularis, and the lymphatic glands. 
 
 4. Examine the Posterior Thoracic Angle. In this you will find the long 
 thoracic nerve and the subscapular artery. Trace branches from this nerve to the 
 serratus magnus. (Fig. 132). Trace the subscapular artery to the muscles of 
 the posterior wall. Find its largest branch, leaving the axillary space by the 
 triangular space, between the teres major and minor and internal to the scapular 
 head of the triceps. 
 
 5. Examine the External or Humeral Angle (Fig. 1 37). Find first the median 
 nerve, lying on the front of the axillary artery. Trace this nerve upward and 
 find its inner and outer heads, from the inner and outer cords of the brachial 
 plexus. 
 
 The ulnar nerve lies to the inner side of the axillary artery. Trace this up 
 to the inner cord of the brachial plexus ; also trace it down behind the inner 
 condyle of the humerus. See where it joins company with the inferior profunda 
 artery. 
 
 The musculo-cutaneous nerve lies to the outer side of the axillary artery. 
 You will find this nerve close to the insertion of the pectoralis minor. Trace it 
 through a hole in the coraco-brachial muscle. It is a branch of the outer cord of 
 the brachial plexus. 
 
 The musculo- spiral nerve lies behind the axillary artery. (Fig. 137.) 
 Trace it downward and it will soon disappear between the two humeral heads of 
 the triceps muscle. It is a branch of the posterior cord of the brachial plexus. 
 
 The circumflex nerve lies behind the axillary artery. It is a branch of the 
 posterior cord of the brachial plexus. It soon escapes to the posterior part of 
 the shoulder by the quadrangular space, with the posterior circumflex artery. 
 
 The subscapular nerves, three in number, lie the most deeply of all the 
 nerves in this region. They are given off to the muscles that form the posterior 
 boundary of the axillary space. The nerve to the latissimus dorsi is called the 
 long subscapular. 
 
 The anterior thoracic nerves are two in number ; they are called external 
 and internal. The internal anterior thoracic nerve is from the inner cord of the 
 brachial plexus ; it supplies the pectoralis minor. The external anterior thoracic 
 nerve is from the outer cord of the brachial plexus ; it pierces the clavi-pectoral 
 fascia and goes to the pectoralis major. The internal anterior thoracic nerve also 
 sends a branch to the pectoralis major muscle. This pierces the clavi-pectoral 
 fascia. 
 
 The internal cutaneous and lesser internal cutaneous nerves are inter- 
 nal to the axillary artery. They must not be mistaken for the ulnar. 
 
196 PRACTICAL ANATOMY. 
 
 The Axillary Artery and Vein. This artery has three stages, as follows : 
 
 1. First stage, from first rib to the pectoralis minor muscle. 
 
 2. Second stage, behind the pectoralis minor muscle. 
 
 3. Third stage, below the pectoralis minor muscle. 
 
 Note that the axillary vein lies internal to the artery in all three stages ; 
 that it receives two large tributaries : (i) the cephalic, (2) the basilic veins. 
 
 Branches of the axillary artery according to stages : 
 
 First Stage. (i) The superior tJwracic passes between the pectoral muscles 
 to the chest walls. Trace branches from it to these muscles and to the thoracic 
 walls. (2) The acromio-thoracic perforates the clavi-pectoral fascia (Fig. 132), 
 and sends branches to the deltoid and pectoral muscles. Its descending branch 
 you found deeply buried in a groove with the cephalic vein, between the deltoid 
 and pectoralis major muscles. 
 
 Second Stage. (i) Alar tJwracic branches have been seen supplying the 
 axillary glands and fat. (2) The long tlwracic you will find in the anterior thoracic 
 angle. Trace its numerous branches to all the walls of the axillary space. 
 
 Third Stage. (i) The anterior circumflex artery you will trace behind the 
 coraco-brachial and biceps muscles. It sends a branch to the shoulder-joint 
 through the bicipital groove. (2) The posterior circumflex passes through the 
 quadrangular space, with the circumflex nerve, to the deltoid muscle and 
 shoulder-joint. The space referred to is bounded externally by the humerus, 
 internally by the scapular head of the triceps, superiorly by the teres minor, 
 inferiorly by the teres major and latissimus dorsi. (3) The subscapular is the 
 largest branch of the axillary artery. You will find it in the posterior thoracic 
 angle. It passes through the triangular space, and takes the name of dorsalis 
 scapulce. This space is bounded by the triceps and the teres minor and major. 
 
 The muscles in this locality are : 
 
 1. The Serratus Magnus. This arises from the outer surface of the upper 
 eight ribs by nine fleshy processes. (Fig. 135.) It is inserted into the anterior 
 lip of the vertebral border of the scapula. It is supplied by the long thoracic 
 nerve, a branch of the brachial plexus. (Fig. 42.) 
 
 2. The Subscapularis Muscle. This arises from the subscapular fossa and 
 is inserted into the lesser tuberosity of the humerus. 
 
 3. The teres major arises from the middle lip of the axillary border of the 
 scapula. It is inserted into the posterior lip of the bicipital groove of the 
 humerus with its synergist, the latissimus dorsi. 
 
 4. The latissimus dorsi is a muscle of the back, and will be described in the 
 proper place. The student will now trace the subscapular nerves, from the pos- 
 terior cord of the brachial plexus to the subscapular, the teres major, and the 
 latissimus dorsi muscles. Also study the relation and manner of insertion of the 
 two latter muscles into the humerus. 
 
 The Brachial Artery. This vessel begins as a continuation of the axillary 
 artery, at the lower border of the teres major muscle. (Fig. 137.) It ends at 
 the elbow, by dividing into the radial and ulnar arteries. In its course you can 
 show the triceps muscle on one side and the biceps and coraco-brachial on the 
 other side of this artery. The median basilic vein lies in front of it, near the elbow 
 (Fig. 105), the bicipital fascia intervening. The median nerve crosses it in the 
 middle of its course. As you must demonstrate on your work, this artery lies 
 superficially in its entire course, and may be easily reached for compression or 
 operation. Find tin- ulnar and internal cutaneous nerves, internal to the artery. 
 Examine every cadaver in the room to find high bifurcations of the brachial 
 artery. 
 
 The branches of the brachial artery are : 
 
 I . The muscular hrancJies to the flexor muscles of the forearm. 
 
 
SHOULDER, ARM, FOREARM, AND HAND. 197 
 
 2. Tlic nutrient artery to the humerus, about the middle. Find the nutrient 
 foramen directed toward the elbow on the inner surface of the humerus, near 
 the insertion of the coraco-brachial muscle. 
 
 3. Tlie Superior Profunda Artery. Find this artery on a level with the major 
 tereal muscle. It accompanies the musculo-spiral nerve in the groove bearing 
 the same name. This artery supplies the triceps and gives off an artery to the 
 upper one-third of the humerus. It anastomoses with the radial recurrent, the 
 posterior ulnar recurrent, and the posterior interosseous recurrent, and with the 
 inferior profunda and anastomotica magna arteries. 
 
 4. The inferior prof nnda you will find a little below the middle of the arm. It 
 joins the ulnar nerve, accompanies the same, and terminates by anastomosing 
 with the anastomotica magna and posterior ulnar recurrent arteries. 
 
THE THORAX. 
 
 ANTERIOR AND LATERAL WALLS. 
 
 Locate (i) the sternum, presternum, mesosternum, metasternum. (2) The 
 suprasternal notch and the interclavicular ligament. (3) Find the pronounced 
 elevation between the first and second pieces of the sternum. This is the manu- 
 brio-gladiolar joint, and is the point concerned in the rule for counting the ribs. 
 
 ] .evator costs and 
 accessor! us 
 
 Scalenus medius 
 
 GROOVE FOR SUBCUWIAN 
 ARTERY 
 
 Scalenus anticus 
 
 GROOVE FOR SUBCLAVIAN 
 VEIN 
 
 SHAFT 
 
 Levator costae 
 Accessorius 
 
 (insertion) 
 Cervicalis ascendena 
 
 (origin) 
 Serratus posticus 
 
 superior 
 
 (insertion) 
 
 Scalenus posticua 
 
 Third dictation of 
 serratus maguua 
 
 External 
 intercostals 
 
 FIG. 138. FIRST AND SECOND RIBS. 
 
 Rule : this ridge corresponds to the cartilage of the second rib. (4) Find tl 
 sterno-clavicular articulation. See if it is freely movable, as it should be. Not 
 when you dissect this region the presence of an interarticular fibro-cartilae 
 dividing the sy no vial cavity into two compartments an inner and an outer. 
 Note that seven true ribs articulate by their cartilages with the sternum ; that 
 except that of the first rib are movable. (6) Examine the metasternum 
 cnsiform jinn-ess to see its deflection, whether lateral, forward, or posterioi 
 (7) Count the ribs and study the nature of the chondro-costal articulation. 
 
 198 
 
THE THORAX. 
 
 199 
 
 Dissect the following structures and study them carefully : 
 
 1. The subclavius muscle and the costo-clavicular ligament. 
 
 2. The external intercostal muscles and their fasciae. 
 
 3. The internal intercostal muscles and their fasciae. 
 
 4. The intercostal fasciae, internal, middle, and external. 
 
 An interartieular 
 ligament 
 
 The plate of flbro- 
 cartilage between 
 manubrium and 
 meso -sternum 
 
 SIXTH RI3 H 
 
 SEVENTH RIB 
 
 FIG. 139. THE STERNUM. 
 (Left side, showing ligaments ; right side, the synovial cavities/ 
 
 5. The anterior chondro-sternal ligaments. 
 
 6. The anterior common sternal ligament of periosteal derivation. 
 
 7. The scalenus anticus, inserted into the scalene tubercle of the first rib. 
 
 8. The scalenus medius, inserted into the scalene depression of the first rib. 
 
 9. The subclavian groove, between the scaleni muscles on the first rib. 
 10. The groove for subclavian vein on the outer surface of the first rib. 
 
200 PRACTICAL ANATOMY. 
 
 1 1. The relation of subclavian artery and vein on first rib. 
 
 12. A digitation of serratus magnus muscle on the first rib. 
 
 13. Study the insertion of the scalenus posticus muscle on the outer surface 
 of the second rib. Also the digitations for the serratus magnus muscle on the 
 second. 
 
 The Subclavius Muscle. Dissection of this muscle requires much care. 
 Cut the costo-clavicular ligament and the sterno-clavicular ligaments and then 
 lift the clavicle. This will bring the muscle into view. The muscle has a strong 
 sheath. Notice that the space between this muscle and the pectoralis minor is 
 bridged by the clavi-pectoral fascia. (Fig. 132.) Note the origin of the sub- 
 clavius from the first rib at the junction of its cartilage ; its insertion into a groove 
 
 External 
 intercoatala 
 
 Internal 
 intercostals 
 
 External 
 intercostals 
 
 Internal 
 
 intercostals 
 
 Infra-costales 
 
 FIG. 140. THE INTERCOSTAL MUSCLES. 
 
 on the under surface of the clavicle, middle two-fourths. The structures you will 
 now see under the clavicle are: (i) The subclavius muscle and its sheath; (2) 
 the subclavian artery and vein ; (3) the brachial plexus of nerves. 
 
 The scaleni muscles are three in number anticus, medius, and posticus. 
 A few movements of the forceps will develop their insertions two into the first 
 and one into the second rib. 
 
 The intercostal muscles and fasciae occupy the intercostal spaces. The 
 intercostal spaces are eleven on each side. Kuch space is occupied by: (i) K\- 
 ternal and internal intercostal muscles ; (2) external, middle, and internal inter- 
 costal fasciae ; (3) intercostal arteries, veins, and nerves. 
 
 The external intercostal muscles are descending /. c., their fibres pass 
 
THE THORAX. 201 
 
 downward and inward, toward the median line of the body. (Fig. 140.) They 
 extend from the tubercle of the rib behind to the costo-chondral joint in front. 
 
 The internal intercostal muscles ascend ; their fibres pass inward, upward, 
 and toward the mid-line of the body. They extend from the sternum in front to 
 the angle of the rib behind. 
 
 The osteology of the ribs must be reviewed. A typical rib has : 
 
 1. A head, or articular vertebral extremity. 
 
 2. A neck, or constiction, anterior to the head, extending to the tubercle. 
 
 3. An articular tubercle, articulating with the transverse process. 
 
 4. A non-articidar tubercle, for ligamentous attachment. 
 
 5. A sternal extremity, for articulation with its cartilage. 
 
 6. An outer surface, covered by numerous muscles. 
 
 7. An inner surface, covered by pleura mostly. 
 
 8. A superior border, for muscular attachment. 
 
 9. An inferior border, possessing two lips and a subcostal groove. You must 
 become familiar with all these points on the dry skeleton. 
 
 POSTERIOR KRAXClf OF LA TF.RA L 
 
 ANTKKTOR BRANCH OF LA TKRAL 
 
 <TTA.\i-:ors xi-; 
 
 THE A \TKKIOR PRI- 
 MARY DIVIIO\ 
 OF AN INTERCOS- 
 TAL M-:ilVE 
 
 THE POSTERIOR PR I- 
 MARY IHVISI<>\ HI-' 
 AN INTERCOSTAL 
 NERVE 
 
 <: \.\i:/,/o\ Oh' I'osTKii- 
 IOK ROOT OF SPINAL 
 M-:I; \-K 
 
 ANTERIOR ROOT OF 
 XPIXAL XEUVE 
 
 .s ) '. V r. I Til /; Tl (' GANGLION A XI 
 RA .MI ( 'OMM I \\/( '. I .V /'/> 
 
 FIG. 141. THE INTERCOSTAL NKKVF.S. 
 
 LATERAL CfTANE- 
 
 or.v 
 
 AN INTERCOSTAL SPACE 
 
 An external intercostal 
 * muscle 
 
 An internal intercostal 
 muscle 
 
 COSTO-CHONDRAL JUNCTION 
 
 Iiili'iiinl iixiiuiiHtry 
 artery 
 
 TEHMISrS 0^ IXTKR- 
 rox r.\i. XKR\'K LYIXI; 
 OX POSTERIOR SUR- 
 FM'K (>/ IXTKftl'OST.I I, 
 MI'SfLK. A\l) PASSIXH 
 f\ FROXT OF THK f\- 
 TK I! XA L .WA MM A R Y 
 ARTfJ/lY 
 
 Figure 140 shows the mnscnli infracostales. These muscles arise near the 
 angle of the rib, from the inner surface and lower border ; they are inserted 
 into the second rib above. They are also called subcostals or mnsculi subcostales. 
 
 Intercostal Fascia. Remove every vestige of the pectoralis major, and 
 expose the intercostal muscles. Find a delicate layer of fascia covering the outer 
 surface of the external intercostal muscle. This is the external intercostal fascia. 
 Trace this fascia to the sternum. You can now see, showing through this fascia, 
 the internal intercostal muscle. The internal intercostal fascia covers the inner 
 surface of the internal intercostal muscle. The middle intercostal fascia is be- 
 tween the two intercostal muscles. 
 
 The Intercostal Nerves. Figure 141 represents the cour'se and divisions 
 and relations of an intercostal nerve, such as may be seen in the second, third, 
 fourth, fifth, and sixth intercostal spaces. Students frequently graduate unable 
 to locate properly an intercostal nerve. You are to note the following stages of 
 an intercostal nerve : 
 
 1. -The nerve is formed by an anterior and a posterior root. 
 
 2. The posterior or sensory root has a ganglion. 
 
 '4 
 
PRACTICAL ANATOMY. 
 
 4. 
 5. 
 6. 
 
 3. The intercostal nerve lies between the pleura and external intercostal 
 muscle. 
 
 The nerve throws off muscular branches. 
 
 The nerve throws off lateral cutaneous branches. 
 
 The nerve is in the substance of the internal intercostal. 
 
 7. The nerve is on the posterior surface of the internal intercostal. 
 
 8. The nerve passes in front of the internal mammary artery. 
 
 9. The nerve throws off anterior cutaneous branches. 
 
 The branches of the intercostal nerve are : (i) Muscular, to the internal and 
 external intercostals, the infracostales, the serratus posticus superior, the triangu- 
 laris sterni, and levatores costarum ; (2) cutaneous branches, lateral and anterior. 
 Now you may find the nerves according to the diagram. You will find the 
 
 Sterno-hyoid 
 
 Stern o-thyroid 
 
 Triangularia 
 a terui 
 
 Transveraalis abdominis 
 
 FIG. 142. THE MUSCLES ATTACHED TO THE BACK OK THE STERNTM. 
 
 intercostal arteries with the nerves to some extent. In this dissection care must 
 be taken not to injure the pleura. 
 
 \\licrc to I'ind tlic Internal Mammary Artery and I'cins. With your forceps 
 go through the soft structures one-half of an inch to the outer margin of the 
 sternum on either side. Try to find this artery, and ligate the same, without 
 injuring the pleura. In reaching this artery, do you cut through the external 
 intercostal muscle? No. Do you cut through the three intercostal fascia.- and 
 internal intercostal muscle? Yes. Give the location of the internal mammary 
 artery. It lies between the pleura and internal intercostal fascia. It has two 
 companion veins. 
 
 The Inner Surface of the Sternum and Ribs (Fig. 142). See : 
 i. The internal intercostal muscles, eleven pairs on each side. 
 
77//1 THORAX. 
 
 203 
 
 
 
 2. The origin of the stcrno-liyoid muscle. 
 3 . The origin of tJie sterno-tJiyroid muscle. 
 
 4. The origin and insertion of the triangnlaris stcrni. 
 
 5. The costal and sternal origins of t/te diapJiragm. 
 
 6. The parietal layer of the pleura, through which you can see the muscles. 
 
 7. The internal mammary artery and veins, on each side of the sternum, 
 giving off their anterior intercostal and other arteries. (Fig. 143.) 8 
 
 Dissection. Cut through the ribs in the mid-axillary line. (Fig. 145.) Cut 
 through the abdominal walls along the margin of the false ribs. Cut through 
 
 PHRENIC NERVE 
 
 Subclavian artery 
 Subclavian vein, cut 
 
 Anterior intercostal branch 
 
 Anterior intercostal branch 
 
 Mnsculo-phrenic artery 
 
 Deep circumflex iliac artery - 
 
 Common carotid artery 
 
 Internal jugular vein 
 Subclarian rein, cut 
 Soaleuus anticus muscle 
 
 Trianpcularis aterni muscle 
 Perforating branch 
 
 Superior epigastric artery 
 
 Deep epigastric artery 
 
 FIG. 143. SCHEME OF THE INTKRNAI. MAMMARY ARTERY. 
 
 the diaphragm close to the ribs and sternum. Then elevate from below 
 the section of thoracic wall you have made loose. As you turn this section up 
 you will see a large amount of anterior mediastinal connective tissue behind the 
 sternum. Elevate the section slowly ; let an assistant divide the connective 
 tissue, and do not injure the numerous structures that enter or leave the apex 
 of the thorax. 
 
 Figure 141 shows the infracostales. These muscles arise near the angle of 
 the ribs, from the inner surface and lower border ; they are inserted into the 
 second rib above. They are also called snbcostals. 
 
204 PRACTICAL ANATOMY. 
 
 The internal mammary artery has the following branches, all of which you 
 can easily find : 
 
 1. The perforating branches that come through the five or six upper inter- 
 costal spaces and supply the major pectoral muscle and the mammary gland. 
 
 2. The mediastinal branches to the mediastinal connective tissue and glands 
 under the sternum. They also supply the thymus gland in the foetus or its 
 remains in the adult, hence they are called also tliyinic 'arteries. 
 
 3. The sternal branches, quite small and numerous, to the sternum and tri- 
 angularis sterni muscle. 
 
 4. Pericardiac brandies to the anterior surface of the pericardium. 
 
 5. The comes nervi phrenici is a long, slender artery that accompanies the 
 phrenic nerve to the diaphragm. You will find this nerve between the pleura 
 and pericardium. 
 
 6. The anterior intercostals supply the six upper intercostal spaces. There 
 are two in each space, one above and one below. They anastomose with the 
 posterior intercostal arteries from the aorta. 
 
 7. The musculo-phrenic, that furnishes the anterior intercostal arteries to the 
 remaining spaces. It also supplies branches to the diaphragm. 
 
 8. The superior epigastric passes through the diaphragm between its costal 
 and sternal parts, enters the sheath of the rectus muscle, finally the muscle itself, 
 and anastomoses with the deep epigastric branch of the external iliac artery. 
 
 The internal mammary artery is a branch of the subclavian, as you saw when 
 you dissected the neck. Its parietal branches are to the anterior walls of the 
 thorax what the parietal branches of the aorta are to the posterior walls of the 
 thorax. Now go down between the sixth and seventh cartilages and find where 
 the artery divides into the musculo-phrenic and superior epigastric. 
 
 The thoracic walls are supplied with blood, then, by intercostal arteries. 
 These arteries come : (i) From the aorta ;' (2) from the internal mammary ; (3) 
 from the subclavian ; this latter furnishing the artery to the superior intercostal 
 space. The blood from this area is collected and delivered as follows : the first 
 or superior intercostal vein is tributary to the vertebral vein ; the others to the 
 azygos veins, in the posterior mediastinal space, to be presently dissected. 
 
 The triangularis sterni muscle arises from the lateral aspect of th( 
 sternum, and is inserted into the cartilages of the third, fourth, fifth, and sixtl 
 ribs. 
 
 INTERIOR OF THE THORAX. 
 
 Geometrically the thorax possesses : 
 
 1. An apex, through which pass : (i) The oesophagus ; (2) the trachea ; 
 common carotid artery on the left, and the innominate artery on the right side ; 
 (4) the phrenic, pneumogastric, sympathetic, and recurrent laryngeal nerves ; (5) 
 the internal jugular and subclavian veins ; (6) the thoracic duct ; (7) the sterno- 
 hyoid and sterno-thyroid muscles ; (8) the third and fourth layers of deep cervi 
 cal fascia form the pericardium and invest the longus colli muscle respectively ; 
 (9) the subclavian artery on the left side. 
 
 2. A base, formed by the diaphragm. This is a niusculo-aponeurotic struc- 
 ture, in relation with the pleurae and pericardium above and below with the 
 peritoneum. It transmits: (i) The aorta; (2) the ascending vena cava ; (3) tin- 
 (i-sophagus and pneumogastric nerves; (4) the superior epigastric branch of the 
 internal mammary artery ; (5) the thoracic duct ; (6) the communicating branch 
 from the lumbar veins to the a/ygos veins. 
 
 
THE TJIOK.IX. 
 
 205 
 
 3. An anterior wall, formed by the sternum and cartilages of the ribs, with 
 their investing soft parts. On this we find the internal mammary arteries and 
 their veins, and the sterno-hyoid, sterno-thyroid, and triangularis stern i muscles. 
 
 4. A posterior wall, formed by the thoracic portion of the vertebral column 
 and the ribs outward from their heads to the angles, with their investing soft 
 parts. 
 
 5. Two lateral walls, formed by the ribs and intercostal spaces, between the 
 angles and the costo-chondral articulations. 
 
 Vena cava superior 
 
 Arch of aorta 
 
 Pulmonary artery 
 
 BRONCHUS 
 
 / 
 Pulmonary vein 
 
 ENSIFORM CARTILAGE 
 
 IK;. 144. ANTERIOR VIEW OK THE LUNGS: PERICARDIUM. (Modified from Bourgery.) 
 
 The inlet or apex of the thorax is bounded by the sternum, first rib, and 
 first thoracic vertebra. The diaphragm is attached to, or rather has its origin from, 
 the sternum, ribs, hgamenta arcuata interna and externa. There are twenty- 
 four ribs, twenty-two intercostal spaces, and forty- four intercostal muscles. 
 
 The interior of the thorax consists of: 
 
 1. A pulmonary portion, a compartment containing the lungs. 
 
 2. A mcdiastinal portion, or non-lung-containing compartment. 
 
 The pulmonary portion of the thoracic cavity contains the lungs. The inner 
 
206 
 
 PR A CTICAL ANA TOM \ '. 
 
 surfaces of ribs are covered by the pleura costalis. The lung is invested by 
 pleura, just as the abdominal organs are invested by peritoneum. The layer of 
 pleura covering the lungs is called visceral layer, or pleura pulmonalis. The 
 pleural cavity is the space between the two layers of pleura. This cavity 
 contains only a small amount of serum for lubrication. You will often find 
 adhesions between the parietal and visceral layers of the pleura, the result of 
 inflammation. Frequently you will find many ounces of fluid, the result of 
 hypersecretion : this condition is hydro-tfiora.v. Occasionally you will find pus 
 in the pleural cavity : this is pyo-tJwrax. You may find foetid gas : this is pneumo- 
 tliorax; or pus and gas, pyo-pneuino-tliorax. 
 
 Pectoralia major muscle 
 Pectoralis minor muaclj 
 
 SUPERIOR LOBE 
 
 , Serratus magnua 
 muscle 
 
 MIDDLE LOBE 
 
 SECTION OF SEVENTH RIB 
 
 Diaphragm 
 
 STERNUM 
 
 ENSIFORM CARTILAGE 
 
 FIG. 145. ANTERIOR VIKW OF THK THORAX \YITII CHKST WALL RKMOVKD, SIIO\VIM; 
 THK LUNGS. (Modified from Bourgery.), 
 
 Cavities of tubercular origin are often found in the lungs. In these case 
 notice the cavity, while an assistant inflates the lung. A large percentage of the 
 cases you see in the dissecting-room have pulmonary tuberculosis ; some have 
 croupous pneumonia ; others, pulmonary gangrene. 
 
 AntJiracosis is carbuncular disease of the lung. This you will find occasion- 
 ally. Every adult lung you will see on the tables will be literally covered by 
 carbonaceous spots. This pigmentation is undoubtedly produced by impure air ; 
 still, you fail to find it in domestic animals at the stock-yards. Possibly if these 
 animals lived forty years, they would show the same spots on their lung 
 surfaces that are found in man's lungs. 
 
 The apex of the lung extends one and one-half inches above the first rib. The 
 
THE THORAX. 207 
 
 base of the lung rests on the pulmonary surface of the diaphragm. The lung has 
 a pleuritic attachment to the vertebral column, called the ligauicntum latmn 
 pulmonis. 
 
 Anatomical Root of the Lung. Like the root of the liver, the root of the 
 lung transmits structures whereby the lung carries on (i) the functional activity ; 
 (2) the nutritive activity of the lung. By the latter the lung as an organ lives ; 
 by the former the lung as an organ aerates the blood. Pull the lung carefully 
 over the cut margin of the ribs (Fig. 145) and you will see the root structures. 
 
 Inflate the lungs and study the lobes and fissures. Introduce a one-half inch 
 rubber tube into the trachea and inflate the lungs. You will then see a space, 
 corresponding to one-third the anterior surface of the heart, that is not covered 
 by the lungs when they are inflated. If you could mark on the chest-wall the size 
 of this space, that would give you the area of precordial dullness on percussion. 
 As you inflate the lungs you notice the right lung has three, the left two, lobes. 
 
 The root structures of the lungs are : 
 
 1. The bronchial tubes, air-conveying conduits. 
 
 2. The bronchial arteries, nutritive conduits to the lungs. 
 
 3. The pulmonary artery, bearing blood laden with CO 2 . 
 
 PLEURA PULMONIS 
 
 PLEURAL CAVITY 
 
 PLEURA COSTAUS 
 
 FIG. 146. INVAGINATION OF PLEURA. 
 
 The three structures produced by invagination of pleura may be schematically represented as the above 
 figure shows. I. The visceral layer, or pars pleurae invaginata. 2. The parietal layer, or pars pleurse 
 costalis. 3. The pleural cavity. The same schemejgives like results in accounting for the cavity and 
 layers in connection with peritoneum and pericardium. 
 
 4. The pulmonary veins, bearing blood -j-O, and CO 2 . 
 
 5. The pulmonary sympathetic nerves, from the pulmonary part of the cardiac 
 plexus. 
 
 You are to learn that the thoracic, abdominal, and pelvic viscera are inner- 
 vated' by the sympathetic nerve. ' The cardiac gangliated plexus supplies the 
 thoracic organs ; the solar, the abdominal organs ; the Jiypogastric, the pelvic 
 organs. Each plexus, however, has a primary element, sympathetic, and a 
 secondary piieumogastric element ; hence we say, in general, the nerve-supply is 
 from the sympathetic. Analytically, we speak of the nerve-supply as sympa- 
 thetic and pneumogastric. 
 
 The Pulmonary Trio. The sympathetic nerve always accompanies the 
 artery to an organ. The artery that nourishes the lungs is the bronchial ; but 
 this artery accompanies the bronchial tube. The pulmonary trio, then, consists 
 of the bronchus, the bronchial artery, and the sympathetic nerve-supply. 
 
 Relation of bronchus, artery, and veins on the two sides are as follows : (i) 
 On the right side, from above down bronchus, artery, and vein. From before 
 back vein, artery, bronchus. 
 
 O the left side, from above down artery, bronchus, vein. From before 
 back vein, artery, bronchus. 
 
208 PRACTICAL ANATOMY. 
 
 What is the relation of the visceral and parietal pleune at t/ie roof of tlic lung f 
 They are continuous, since the pleura is an invaginated sac. (Fig. 146.) 
 Name the three structures produced by a simple invagination of the pleura. 
 
 1. The visceral layer, or the pars pleurae invaginata pleura pulmonis. 
 
 2. The parietal layer, or the pars pleura costalis parietal pleura. 
 
 3. The space between the two layers, the pleural cavity. 
 What are the grand divisions of the parietal pleura f 
 
 The diaphragmatic, the mediastinal, the external or costal. The diaphrag- 
 matic rest on the diaphragm ; the costal on the ribs and internal intercostal mus- 
 cles ; the mediastinal is in relation with the contents of the mediastinum. 
 
 Has the upper extremity of the pleura pulmonis any important relations / 
 
 Yes ; it extends an inch above the first rib, and is in relation to the sub- 
 clavian vessels, which lie in front and internal to the apex of the pleura. 
 
 Is there any special provision made for strengthening- or protecting that part of 
 the dome of the pleura that projects abm>e the first rib ? 
 
 Yes ; there is a heavy layer of subpleural connective tissue, called Sibson's 
 fascia, that descends from the scaleni muscles to the first rib and gives strength 
 to the dome. 
 
 HOIV is the root of each lung secured to tJie diaphragm f 
 
 By a fold of pleura called the ligamentum latum pulmonis. 
 
 Name the geometrical parts of the lung. 
 
 The apex, base, outer surface, inner surface, posterior border, anterior border, 
 and pulmonary root. 
 
 What is the inner surface of the lung ? 
 
 That part in contact with the mediastinum and pericardium ; it is concave. 
 
 Where is the base of the lung and what is its shape f 
 
 It is in contact with the diaphragm ; it is concave. 
 
 What can you say about the anterior border of the lung ? 
 
 It is sharp and thin, and separates the external from the inner border. The 
 posterior border is thick and round, and occupies the deep groove on each side 
 of the vertebral column. 
 
 Is there any provision made for possible physiological increase of breathing- 
 space in the pleural spaces ? 
 
 Yes ; the same principle is here seen as is observed in the tortuous arteries of 
 some localities a condition apparently foreseen to meet an emergency. The 
 lung, under ordinary conditions of man, is less extensive than the pleural sacs. 
 The parietal pleura is really tortuous in the region of the anterior border of the 
 lung. The emergency that would take the kinks out of this pleura would be 
 physical training, where wind is the prime desideratum, as in pugilistic mills. 
 The same principle is seen in a pregnant uterus, reducing the tortuosity of uter- 
 ine arteries. 
 
 THE MEDIASTINAL SPACES. 
 
 1. Anterior Is the space between the heart and sternum. 
 
 2. Middle Is the space occupied by the heart and its root structures. 
 
 3. l\>stcrior Is the space behind the heart. 
 
 The Contents of the Anterior Mediastinal Space : 
 
 1. The remains of tlic thy inns gland a fu-tal structure. 
 
 2. The left bracJno-ccplictlic or left innominate rein. 
 
 3. The internal mammary artery and its companion veins. 
 
 4. The nearly obsolete triangnlaris sterni muscle. 
 
 5. The origin of the sterno-hyoid and sterno-tltyroid muscles. 
 
 6. The large amount of connective /issue you noticed when you opened the 
 thorax. 
 
/'///: THORAX. 
 
 Contents of Middle Mediastinal Space : 
 
 I. Pericardium and heart, and the cardiac root structures. 
 Phrenic nerve and its artery ctrtcria comes ncrvi phrenici. 
 The aorta, pulmonary artery, and pulmonary vein. 
 The vena cavce, superior and inferior, ascending and descending. 
 The trackeal bifurcation and the two bronchial tubes. 
 Bronchial lymphatic glands and their vessels and nerves. 
 The cardiac plexus of the sympathetic nerve. 
 
 HYOID BONE 
 
 Thyro-hyoid membrane 
 
 THYROID CARTILAGE 
 
 Sterno-thyroid muscle 
 Crico-thyroid 
 membrane 
 
 Crioo-thyroid muscle 
 
 THYROID GLAND 
 
 Right common earotid 
 
 artfrii 
 
 RIGHT PNEUMO- 
 GASTRIC NERVE 
 
 Ili'ihl in/midl jii'/idnr 
 rein 
 
 Level of sternum 
 
 SECTION OF CLAVICLE 
 SECTION OF FIRST RIB 
 
 SECTION OF STERNUM 
 
 Thyro-hyoid muscle 
 
 Lateral portion erieo- 
 thyroid membrane 
 
 Omo-hyoid muscle 
 
 7 Sterno-mastoid muscle 
 
 CRICOID CARTILAGE 
 FIRST RING OF TRACHEA 
 
 TRACHEA 
 
 Left suspensory 
 
 ligament 
 LEFT RECURRENT 
 
 NER VJJ 
 
 (Esophagus 
 
 Left innominate vein 
 
 LEFT LOBE OF TIIYMUS 
 
 Left internal mammary 
 artery 
 
 Pericardium 
 
 SECTION OF FIFTH RIB 
 CARTILAGE 
 
 ENSIFORM CARTILAGE 
 
 FIG. 147. THYMUS GLAND IN A CHILD AT BIRTH. 
 
 The Posterior Mediastinal Contents : 
 
 1. The aorta and posterior intercostal arteries. 
 
 2. The oesophagus and pneumogastric nerves. 
 
 3. The vena asygos and intercostal veins. 
 
 4. The thoracic duct and its fatty bed. 
 
 5 . The thoracic .gangliated sympathetic cord. 
 
 6. The greater, lesser, and smallest splanchnic nerves. 
 
210 PRACTICAL ANATOMY. 
 
 7. The intercostal nerves, each giving off" two communicating branches ranii 
 coinnmnicantes to the ganglia of the sympathetic nerve in the thorax. 
 
 Dissection of these regions must be done with the forceps. No cutting instru- 
 ment should be used. Proceed in this order: (i) Find the phrenic nerve, a 
 branch of the third and fourth cervical, and the arteria comes nervi phrenici, a 
 branch of the internal, mammary artery, on either side of the pericardium, 
 between this structure and the pleura. This nerve comes from the third and fourth 
 cervical plexus. It lies on the scalenus anticus muscle in the neck. It enters 
 the mediastinal space between the subclavian artery and vein. It passes anterior 
 to the root of the lung. It communicates with the sympathetic, with the nerve 
 
 SUP* v. c 
 
 FORAMEN OVALE 
 
 PLAC E N T A 
 Fu;. 148. SCIIKMU OK THE ]''<KTAI. CIRCULATION. 
 
 to the subclavius, and with the ansa hypoglossal loop. It is distributed to the 
 diaphragm, pleura, pericardium, and diaphragmatic peritoneum. 
 
 The pericardium has : (i) A base, attached to the diaphragm ; (2) an apex. 
 continuous above with the third layer of deep cervical fascia. It may have 
 much fat. It has a visceral layer, a parietal layer, and a cavity. The latter is 
 the space between the two layers, and contains a small quantity of fluid for lubri- 
 cation. It may contain many ounces of fluid this is hydro-pericardium. Note 
 the relation of the inflated lung to the pericardium and poststernal connective 
 tissue. (Fig. I IO.) Make traction on the diaphragm where the pericardium is 
 attached, and observe that this cannot IK- depressed because of its continuity with 
 the third layer of the cervical fascia. Inflate the pericardiac sac ; then cut the 
 parietal layer of the pericardium. 
 
THE THORAX. 211 
 
 The Thymus Gland or Body. You will find the fibrous remains of this 
 gland on the anterior part of the pericardium in the adult, in the anterior inedias- 
 tinal space. This gland is a structure of foetal life ; in children two years old it is 
 quite large. (Fig. 147.) In the four months' foetus the thymus is in appearance 
 like the lung, on casual examination, and is frequently mistaken for this organ 
 by the novice. 
 
 The cardiac root structures are : 
 
 1. The coronary, or nutrient, artery to the heart, from the aorta. 
 
 2. The voice cavo?, coming from the whole body with venous blood. 
 
 3. The pulmonary arteries, conveying blood to the lungs. 
 
 4. The pulmonary veins, returning blood from the lungs. 
 
 5. The aorta, distributing blood to the whole body. 
 
 6. The cardiac branches, from the sympathetic and vagus nerve. 
 
 How to Study Relations of These Structures Which You liavc UOT.V Exposed, 
 
 SUPERIOR LOBE OF RIGHT LUNG 
 
 Aorta 
 
 Pulmonary artery 
 flIGHT AURICULAS APPENDIX 
 MIDDLE LOBE 
 
 OUCTUS ARTERIOSUS 
 
 Pulmonary artery 
 
 SUPERIOR LOBE OF LEFT 
 LUNG 
 
 . LEFT AURICULAR APPENDIX 
 
 ~i j Pulmonary artery 
 
 INFERIOR LOBE 
 i Descending aorta 
 
 FIG. 149. ANTERIOR VIEW OF FCETAL HEART, VESSELS, AND LUNGS. 
 
 Regardless of the Particular Arbitrary Space (Fig. 145). (i) Locate in the mid- 
 dle the ascending part of the arch of the aorta (Fig. 153); (2) to the right of this 
 is the descending vena cava above and the ascending vena cava below ; (3) to 
 the left of the aorta is the common pulmonary artery. The remaining struc- 
 tures are the pulmonary veins, which may be seen by turning the apex of the 
 heart toward the right sjioulder. 
 
 Notice now particularly the pulmonary artery (Fig. 148), for it is the one 
 structure in this root that complicates relations. At its origin it overlaps the 
 first part of the aorta ; separate these vessels the aorta from the pulmonary 
 artery. Next it divides into a right pulmonary and a left pulmonary. The left 
 pulmotiary passes to the left lung, in front of the descending aorta and left 
 bronchus. The right pulmonary artery passes to the right lung, behind (i) the 
 aorta, (2) the vena cava, (3) the phrenic nerve and its artery, and (4) below the 
 right bronchus. 
 
 The ductus arteriosus (Fig. 149) in the foetus is a vessel connecting the pul- 
 
212 
 
 PRACTICAL ANATOMY. 
 
 monary artery and the under surface of the arch of the aorta ; in the adult you 
 must find here in this place the fibrous remains of this foetal structure. 
 
 The ascending vena cava passes through the caval opening in the dia- 
 phragm. You see it when you open the pericardium. Its length is about one- 
 half of an inch, above the diaphragm in the pericardium. 
 
 Right common carotid 
 
 artery 
 
 Right internal jugular 
 vein 
 
 RIGHT LYMPHATIC DUCT 
 
 Innominate artery 
 
 RIGHT PNEUMO- 
 
 GASTRIC NER VE 
 
 Right innominate vein 
 
 Internal mammary vein 
 
 Trunk of the pericardiac 
 and t/iymic veins 
 Vena cava superior 
 
 Vena azygos major 
 
 Vena azygos minor, cross- 
 ing spine to enter vena 
 azygos major 
 
 Hepatic veins 
 
 Vena cava inferior 
 
 Right phrenic artery 
 Cveliac axis 
 
 Rig/it middle suprarenal 
 artery 
 
 Right spermatic artery 
 Right spermatic vein 
 
 Left common carotid 
 
 artery 
 LEFT PXKC 
 
 TRIC SERVE 
 
 THORACIC DUCT 
 
 Ly't innoininnli r- in 
 
 Left subclavian artery 
 
 Left superior intercostal 
 vein 
 
 RECURKKXT 
 LARYXGEAL 
 XER VE 
 
 Vena azygos tertius 
 
 (ESOPHAGUS 
 
 Left upper azygos vein 
 
 (Esophageal brnm-.'iex 
 from aorta 
 
 Vena azygos minor 
 
 THORACIC DUCT 
 
 Left phrenic artery 
 
 Li'fl iniild/i- 
 
 artery 
 
 RECEPTACULUM CHYLI 
 
 f!u/n-ri<ir mi-s 
 artery 
 
 Left ascetidini/ lumbar 
 
 vein 
 Left spermatic vessel* 
 
 Inferior mesenteric 
 artery 
 
 In.. 150. --Tm ARCH OK THE AORTA, THK THORACIC AORTA, AND THE ABDOMINAL AOHTA, \\TIH 
 
 THE SUI'KRIOR AND iNhl.KIoK V 1 N\ C\VA AND THK. INNOMINATE AND AZYGOS Vl-'.IN.s. 
 
 The descending vena cava is made up by the confluence of the right and 
 left brachio-cephalic or innominate veins ; and the vena azygos major, tin- pen- 
 cardiac, thymic, and cesophageal veins are its subsequent tributaries. It returns 
 the blood to the right auricle of the heart from above the diaphragm. 
 
 The brachio-cephalics right and left, also called the innominate veins 
 
THE THORAX. 213 
 
 are formed by the confluence of the internal jugular veins and the subclavian 
 and the lymphatic ducts. (Fig. 150.) 
 
 The left brachio-cephalic vein (Fig. i 50) is the one structure that complicates 
 relations at the root of the neck. This vein lies in the anterior mediastinal 
 space, behind the first piece of the sternum. Great care must be taken not to 
 rupture this vessel or its tributaries when you remove the sternum and subse- 
 quently dissect this region. It is formed by the confluence of the left internal 
 jugular vein, the thoracic duct, the left subclavian vein, the left superior intercos- 
 tal, and the inferior thyroid veins. It crosses (i) the left subclavian artery ; (2) 
 the left common carotid artery ; (3) the two pneumogastric nerves and the left 
 phrenic nerve ; (4) the innominate artery ; (5) the left recurrent laryngeal nerve ; 
 (6) the trachea ; (7) the oesophagus. 
 
 The thoracic duct (Fig. i 50) in many cases is filled with blood, the valves 
 at its terminus not being able to resist the pressure, used in embalming the 
 dissecting material. The many cases reported by students of absence of this ves- 
 sel have no foundation in fact, but belong to a host of finds and absences which 
 may collectively be known as cases of first dissection. 
 
 Develop now the origin from the aorta of the innominate, the left common 
 carotid, and left subclavian arteries. You have dissected the branches of these 
 structures in your work on the neck ; now review their relations. See the innom- 
 inate artery dividing behind the right sterno-clavicular articulation into the right 
 common carotid and right subclavian arteries. 
 
 The thoracic part of the aorta has two divisions. The student will have 
 noticed that this structure is in both the middle and posterior mediastinal spaces. 
 You must remember that classification of structures in reference to specific 
 regions is at best a very arbitrary institution ; that a knowledge of anatomy con- 
 sists in a thorough acquaintance with organs wherever found, rather than in an 
 ability to recite instanter an artificial, arbitrary classification of structures found 
 in parte in a given region. 
 
 1. The aortic arch three propositions: (i) It begins at second sterno- 
 chondral articulation on the right side ; (2) it ends at the fifth thoracic vertebra 
 on-left side ; (3) its branches are : coronary, innominate, left common carotid, left 
 subclavian arteries. 4 
 
 2. The thoracic aorta three propositions : (i) It begins at the fifth thoracic 
 vertebra on left side. (2) It ends at the twelfth thoracic in the mid-line. (3) Its 
 branches are : (i) Pericardiac to the pericardium ; (2) cesophageal to the oesopha- 
 gus ; (3) bronchial to the bronchi, and lung-substance ; (4) the posterior medias- 
 tinal branches, to the glands and connective tissue ; (5) the intercostals, ten in 
 number, to the muscles and fasciae in the intercostal spaces and to the skin cov- 
 ering these structures. 
 
 Practical Dissection Observations. (i) Note that the branches to the bronchi, 
 oesophagus, glands, and pericardium are given off from the anterior part of the 
 aorta, or some derivative of the same. (2) Note that the mediastinal glands, in 
 nearly every case, contain a fluid of inky-black color. This dark color is pro- 
 duced by absorption of anthracite particles. When enough has accumulated to 
 produce carbuncnlar disease of the lung, the patient has anthracosis. You must 
 make this practical distinction : Every lung you find will have carbonaceous pig- 
 mentations ; not every lung will have enlarged, inky-fluid-containing lymphatics 
 only some will show this condition. Some lungs will possess carbuncular 
 nodules and nodes ; these always have enlarged lymphatics, filled with inky fluid, 
 if the disease is anthracosis. 
 
 Conclusion. In every adult cadaver you will see pigmcnted lungs. In 
 some cadavers you may see anthracotic lungs that is, chronic interstitial pneu- 
 monia, produced by inhalation of atmospheric impurities, the basis of which is 
 carbon. 
 
2I 4 
 
 PR A CTICAL ANA TO MY. 
 
 A Posterior View of the Thoracic Viscera (Fig. 151). Turn the lung still 
 further to the left and you can see the following structures even without cutting 
 structures as shown in the figure : ( i) The aorta giving off its intercostals behind, 
 and its visceral branches in front ; (2) the trachea, left bronchus, oesophagus, and 
 thoracic duct behind the transverse arch of the aorta ; (3) the pulmonary veins, 
 right and left, leading to the left auricle of the heart ; (4) the recurrent laryngeal 
 branch of the left pneumogastric nerve ; (5) the trachea, bifurcating into the right 
 and left bronchi, opposite the fifth thoracic vertebra ; (6) the right and left pneu- 
 
 (ESOPHAGUS 
 TRACHEA 
 
 Innominate artery 
 
 RIGHT 
 PNEUMOGA STRIC 
 
 NERVE 
 Vena cava superior 
 
 Intercostal artery 
 
 THORACIC DUCT 
 
 Left subclavian artery 
 
 LEFT PNEUMO- 
 GASTRIC NER VE 
 LEFT RECURRENT 
 l.AR YNGEA L NER VE 
 
 Intercostal artery 
 
 Pulmonary artery 
 
 BRONCHIAL GLANDS 
 
 Intercostal artery 
 
 LEFT BRONCHUS 
 
 />/< pulmonary vein 
 
 Descending aorta 
 
 LEFT PLEURA 
 
 Oblique vein 
 
 Left coronary artery 
 
 Coronary sinus 
 
 Ijfft marginal branch of 
 left coronary artery 
 
 Ventricular branches of 
 coronary artery 
 
 Left ventricle 
 
 RIGHT BRONCHUS 
 Intercostal artery 
 Bronchial artery 
 
 POSTERIOR 
 MONARY /'/,/;. \TX 
 
 Hiijht jmliiiunnry in ti'ry 
 Right pulmonary vein 
 
 Vena azygos major 
 
 'RIGHT PLEURA 
 
 Lfft auricle 
 
 Posterior cardiac vein 
 
 Posterior intrrn nt i iftihir 
 branch of right coronary 
 artery 
 
 Fic;. 151. THK HKART AND GKKAT YKSSKI.S, \VITII TIIK ROOT 01- TIIK I.UNC.S, SKEN KK<>M 1:1 IIIND 
 
 (St. Bartholomew's Hospital Museum.) 
 
 mogastric nerves ; (7) the pulmonary sympathetic plexus; (8) some bronchial 
 lymphatic glands. 
 
 The Cardiac and Pulmonary Plexuses. ( )n the posterior part of the. 
 bronchi you will find some nerves ; these form the posterior pulmonary plexus. 
 On the front of the bronchi you will also find some nerves ; these form the anterior 
 pulmonary plexus. Now cut through the trachea two inches above its bifurcation, 
 and you will sec, immediately in front of the bifurcation, the deep eardiac plexus. 
 Look under the arch of the aorta and see the superficial eardiae plexus. 
 
 The above plexuses furnish nerves that supply the heart and lungs. The 
 pulmonary plexus is a subdivision of the cardiac plexus. The terms anterior and 
 posterior pulmonary are used for convenience in describing the particular regions 
 
THE THORAX. 
 
 215 
 
 occupied by the plexuses. The terms superficial and deep cardiac are used for 
 the same reason. The cardiac plexus is formed as follows : 
 
 1. By cervical and thoracic branches of the pneumogastric nerve. 
 
 2. By branches from the recurrent laryngeal nerve. 
 
 3. By branches from the cervical sympathetic nerve. 
 
 to G.ofRoot ofPneunwy. 
 tofetrosal ff.o 
 Glosso-ph, 
 
 G.*GANGLION. 
 
 Cardiac br.fkPneumogastnc p.= PLEXUS. 
 andRtc.Larynyeal Kcrvts A.> ARTERY. 
 
 1.2.3.4. BRAN CHES. 
 FROM PNEUMOGASTHIC 
 
 \ f f-nr i NERVE TOTHECAROIAC 
 
 \G-ofWrisberg 
 
 VuhantoS-PGanglicri 
 
 + r so *_ LaraeS.Petrosal 
 
 iff u. offnc turwyajtric 
 
 ' toffypoyloaaal Jf. 
 
 <r. of Ext. CdroticLA. 
 
 toPha.ryngea.1 P 
 to Inf. Thyroid A . 
 
 Cardiac Plexus 
 
 .Coronary Plexus 
 
 tro-duadenal 
 
 4th.. 
 
 5^ 
 
 from Coayyoal 
 
 5 Sup.Ifemorrhoidal . 
 6 Spermatic Plexus. 
 
 Pelvic P. orlnfflypogastric. 
 
 SUPPLIES ALL THE PELVIC VISCERA AND THE PENIS. 
 
 GangKon Impar. 
 
 Irsffi'tbtters Compmd of Anatomy. 
 FIG. 152. THE SYMPATHETIC SYSTEM OF NERVES. 
 
 Dissection of tlie Posterior Mediastinal Space (Fig. 150). Remember, you are 
 not to remove the heart and lungs in order to dissect the space. Modus oper- 
 andi : (i) Turn the right lung to the left side. This is easily done, provided there 
 are no pleural adhesions. Where adhesions exist, these must be broken up. (2) 
 Separate the parietal pleura from the ribs, at the cut margin of the ribs, and you 
 
216 PRACTICAL AN ATOM \. 
 
 can then remove it from its parietal attachment, toward the mid-line of the body, 
 to the place where it is reflected on to the lungs, just as easily as a paper-hanger 
 removes his paper from the wall, for purposes of proper adjustment, before his 
 paste becomes set. (3) You now see the subpleural connective tissue the 
 medium intervening between the chest walls and the pleura. 
 
 The structures now seen are (Figs. 150 and 152): The fibres of the inter- 
 nal intercostal muscles, terminating near the angle of the ribs posteriorly. The 
 space between this pleura and the vertebral column is occupied by fatty connec- 
 tive tissue, which must be dissolved in gasolene, ether, or benzine. Now you 
 will see, as in figure 150, the intercostal arteries, veins, and nerves lying on the 
 external intercostal muscles. You soon lose sight of these structures, for they 
 pass between the intercostal muscles. 
 
 The thoracic gangliated cord of the sympathetic nerve (Fig. 152) is easily 
 dissected, but requires a delicate touch to preserve its integrity, such is the deli- 
 cacy of its structure. You can find a ganglion opposite the head of each rib. 
 Trace two little branches from this ganglion to the spinal nerve ; these branches 
 are the rami communicantes. 
 
 Figure 151 shows the spinal nerves near their exit from the intervertebral 
 foramina, giving communicating branches rami communicantes to the ganglia 
 of the thoracic sympathetic cord. It also shows the manner in which the si.v 
 upper distribute their branches to the thorax, and the six Icnver their branches to 
 the abdomen by the splanchnic nerves. 
 
 Branches of the Thoracic Gangliated Cord (Fig. 152). (i) To the spinal 
 nerves rami communicantes ; (2) branches connecting the ganglia ; (3) branches 
 of distribution. Notice the six upper ganglia give off branches to the aorta and 
 its branches in the thorax, to the bodies of the vertebrae and their ligaments, and 
 to the pulmonary and cardiac plexuses. Notice the six lower give off branches, 
 (i) to the aorta and its thoracic branches, (2) and unite to form the splanchnic. 
 
 The splanchnics are the great abdominal visceral branches from the thor- 
 acic part of the gangliated cord ; they are named 
 
 1. The greater splanchnic nerve (sixth, seventh, eighth, and ninth). 
 
 2. The lesser splanchnic nerve (tenth and eleventh). 
 
 3. The smallest or renal splanchnic nerve (twelfth). 
 Can these nerves be seen f 
 
 Yes, easily. The scheme, as set forth in figure 152, can.be verified by any 
 student on any cadaver, with the proper care. Note that the three splanchnic 
 nerves pass through the diaphragm. When we study the thoracic aorta we will 
 see what becomes of the branches of distribution from the upper six thoracic 
 ganglia ; we must ask, Why are they so small, when the six lower are so large? 
 
 The vena azygos major lies on the vertebral column. (Fig. 150.) It i 
 composed of the intercostal veins from the thoracic walls. The blood from th 
 intercostal spaces of the left side is collected by the vena azygos minor. Some 
 times two small azygos veins will be found on the lett side. The minor is tribu- 
 tary to the major azygos vein. Remember, the lett superior intercostal vein i> 
 tributary to the left brachio-cephalic ; the right to the vertebral vein. 
 
 'The thoracic duct lies in a bed of fatty connective tissue, between the aorta 
 and the vena a/ygos major, on the vertebral column. It is confluent to the left 
 brachio-cephalic vein. It originates in the receptaculum chyli, on the second 
 lumbar vertebra. It passes through the aortic opening in the diaphragm. This 
 is easily inflated, in the recently-dead, before the material lias been embalmed. 
 To do this inflation, cut into the brachio-cephalic and find the orifice of the duct. 
 
 The oesophagus extends from the pharynx to the stomach. It leaves the 
 thorax |>y the o-sophagcal opening in the diaphragm. Find it passing behind 
 (i) the arch of tin- aorta, (2) the trachea, (3) the left bronchus. (4) the left com 
 
 : 
 
THE THORAX. 
 
 217 
 
 mon carotid and left subclavian veins, and (5) pericardium. Find (6) the vena 
 azygos major to the right, and (7) the aorta to the left. On each side find (8) 
 the pneumogastric nerves. Near the diaphragm find (9) the left pneumogastric 
 in front, (10) the right behind the oesophagus a result of rotation of the stomach. 
 The pneumogastric nerves (Fig. 153) have been thoroughly considered in 
 the dissection of the neck. Still, there are some practical relations of this nerve 
 
 RIGHT RECUR- 
 RENT LARYN- 
 GEAL NERVE 
 
 Transverse cervical 
 
 artery 
 Right common carotid 
 
 artery 
 Suprascapular artery 
 
 Internal jugular vein 
 
 PNEUMO GA STRIC 
 NERVE 
 
 Subclavian vein 
 
 Inferior thyroid vein 
 PHRENIC NER VE 
 Left innominate vein 
 Ascending aorta -J-^ 
 
 |r 
 
 Superior vena cava 
 RIGHT BRONCHUS 
 
 Branch to superior lube 
 
 of lung 
 
 Upper branch of right 
 
 pulmonary urti'ri/ 
 
 Branch to middle lobe 
 
 of lung 
 Right pulmonary vein 
 
 RIGHT AURICLE 
 
 Right coronary artery 
 Lower branch, of right 
 pulmonary atii'ri/ 
 THORACIC VERTEBRA 
 
 Intercostal vein 
 
 Intercostal artery 
 
 Vena azygos major 
 
 Intercostal vein 
 Intercostal artery __ 
 
 Intercostal vein 
 Intercostal artery 
 
 THYROID BODY 
 LEFT RECURRENT 
 LARYNGEAL 
 NER VE 
 PNE UMO GA S TRIC 
 
 NERVE 
 Left internal jugular 
 
 vein 
 Left common carotid 
 
 artery 
 Left subclarian artery 
 
 Left subclavian vein 
 
 TRACHEA 
 
 Inferior thyroid vein 
 
 PHRENIC NER VE 
 
 (hooked aside) 
 RECURRENT 
 LARYNGEAL 
 NERVE 
 PNEUMOGASTRIC 
 
 NER VE 
 DUCTUS ARTERIOSUS 
 
 Left pulmonary artery 
 
 Pulmonary artery 
 
 Right pulmonary 
 artery 
 
 LEFT BRONCHUS 
 
 Left coronary artery 
 
 Upper left pulmonary 
 
 . vein 
 RIGHT VENTRICLE 
 
 (Conus arteriosiis) 
 Lower left pulmonary 
 
 artery 
 Lvuier left pulmonary 
 
 vein 
 
 CESOPHAGUS 
 (hooked aside) 
 
 THORACIC DUCT 
 Thoracic aorta, 
 
 FIG. 153. THE ARCH OF THE AORTA, WITH THE PULMONARY ARTERY AND CHIEF BRANCHES OF 
 
 THE AORTA. 
 (From a dissection in St. Bartholomew's Hospital Museum.) 
 
 in the thorax I wish the student to understand. The pneumogastric nerve 
 leaves the cranium by the jugular foramen. You found it in the carotid sheath, 
 between the internal jugular vein and common carotid artery in the neck. The 
 two pneumogastric nerves differ in their relations somewhat, hence dissect them 
 separately. The right nerve (Fig. 15 3) crosses the right subclavian artery, and 
 at once gives off its recurrent or inferior laryngeal nerve, which passes upward 
 and inward, behind the subclavian and common carotid arteries, to the larynx, 
 15 
 
2i8 PRACTICAL ANATOMY. 
 
 lying, in its course, between the oesophagus and trachea, in a bed of fatty connec- 
 tive tissue. In the lower part of the neck, cervical and thoracic cardiac branches 
 are given off to the cardiac plexus. A little lower are given off pulmonary 
 branches, called, from their distribution, anterior and posterior ; these supply the 
 lungs through the pulmonary gangliated plexus. CEsophageal branches from 
 the pneumogastric form the plexus gulae. The pneumogastric nerve leaves the 
 thorax by the oesophageal opening in the diaphragm, and sends branches to the 
 solar plexus, from which, possibly, all the abdominal organs receive pneumogas- 
 tric influence. This, however, is purely physiological speculation. 
 
 On the left side, the pneumogastric nerve passes behind the left brachio- 
 cephalic vein and in front of the arch of the aorta. As it is crossing the arch it 
 gives off its recurrent laryngeal branch. This nerve passes to the outer side of 
 the ductus arteriosus and gains the side of the left bronchus and trachea. The 
 inferior or recurrent laryngeal nerves supply branches to the trachea, oesophagus, 
 and to all the intrinsic muscles of the larynx except the crico-thyroid muscle. 
 
 The coronary arteries supply the heart. They are given off from the ascend- 
 ing aorta. They embrace at their origin the common pulmonary artery by their 
 divergence. (Fig. 153.) Blood is returned from the heart by two sources : (i) 
 By minute veins which end in the foramina of Thebesius in the right auricle of the 
 heart. (2) Numerous veins come together to form the great coronary sinus. 
 This sinus opens into the right auricle of the heart, between the auriculo- 
 ventricular opening and the ascending vena cava. You will demonstrate this 
 opening, and also the valve, called the coronary, on your dissection. 
 
 The Right Auricle of the Heart. Cut through the wall of the auricle from 
 the ascending to the descending vena cava in a direction from above downward. 
 Now, having thoroughly washed the parts, you will see : (i) The appendix auri- 
 cula, and (2) the atrium, sinus, or principal cavity of the auricle. In the atrium 
 see and locate: (i) The fossa waits, surrounded by a rim called the annnlns 
 ovalis; (3) the caval and auriculo-ventricular openings (Fig. 154); (4) the coro- 
 nary valve or valve of Thebesius and the RustacJiian valves, -at the respective 
 openings for the coronary sinus and ascending vena cava ; (5) the musculi pec- 
 tinati, which you will see on cutting through the appendix auriculae. These latter 
 are mechanical devices for giving strength to the walls of the auricle, analogous 
 to the chordae tendineae in the ventricles. 
 
 The Semilunar Valves (Fig. 154). Cut into the aorta and pulmonary 
 artery an inch above where they leave the heart, and demonstrate these valves. 
 Fill the vessels with water and show the action of these valves in preventing 
 regurgitation. In the central point of each free margin of the valve find the 
 corpus Arantius. This is a mechanical device, whereby the valves occlude more 
 perfectly. Also find in the aorta the sinuses of Valsalva, or aortic sinuses, oppo- 
 site to which are found the attached margins of the valves. Above the fret 
 margin of the valves find the coronary arteries, left and right, given off from tin 
 aorta. 
 
 The auriculo-ventricular valves, right and left, guard the respective open- 
 ings between the auricles and ventricles. Cut into the right ventricle (Fig. i 54) 
 and study the mechanical devices known as columnar carneae and chorda ten- 
 dineae ; also the left ventricle study in the same manner. 
 
 The septa are : (i) The interauricular. In this you see the fossa ovalis. In 
 the foetus this was a communication between the auricles, called the forumei 
 ovale. It is in the posterior wall of the right auricle. (2) The interventricular, 
 separating the ventricles. 
 
 Steps in Adult Circulation. ( i ) Blood is taken from below the diaphragm 
 by the inferior vena cava, and from above the diaphragm by the descending 
 \vna cava, to the right auricle of the heart. (2) Blood flows from the right 
 
 s 
 
 
 
 
 
THE THORAX. 
 
 219 
 
 auricle* through the auriculo-ventricular opening, to the right ventricle. This 
 opening is guarded by the right auriculo-ventricular valves. (3) Blood flows 
 from the right ventricle, by the pulmonary artery, to the lungs. This artery is 
 guarded by the pulmonary semilunar valves. (4) Blood flows from the lungs to 
 the left auricle of the heart by the pulmonary veins. These veins have no valves. 
 (5) Blood passes from the left auricle, by the left auriculo-ventricular opening, 
 
 Left carotid 
 Innominate 
 
 Left subclavian 
 
 Right pulmonary artery 
 Duclus arteriosus 
 
 Left pulmonary artery 
 
 Pulmonary artery 
 Pulmonary semilunar valves 
 
 LEFT AURICULAR APPENDIX 
 
 Small papillary muscle connected 
 with septum 
 
 (1) Columna caruea 
 
 CHORD/E TENDINE* 
 
 Anterior papillary 
 muscle 
 
 Left coronary artery 
 
 Vena cava inferior 
 ANTERIOR SEGMENT OF TRICUSPID VALVE 
 
 RIGHT SEGMENT OF TRICUSPID VALVE 
 
 SECTION OF VENTRICULAR WALL 
 
 Vena cava inferior . 
 
 lary muscle 
 
 FIG. 154. ANTERIOR VIEW OF THE RIGHT CHAMBERS OF THE HEART, WITH THE GREAT VESSELS. 
 
 (3) Posterior papil- (2) Columna oarnea 
 ile 
 
 to the left ventricle. This opening is guarded by the left auriculo-ventricular 
 valves. (6) Blood passes from the left ventricle through the aorta to all vascu- 
 lar parts of the body. The aorta is guarded by the aortic semilunar valves. 
 Systole is a term by which contraction of the auricles and ventricles is desig- 
 nated ; diastole is its opposite. The one extrudes, the other draws in, blood. 
 
 The Foetal Circulation. The lungs are essentially organs whose use in 
 distributing the blood for purification begins after birth. Before the product of 
 
220 PRACTICAL ANATOMY. 
 
 conception reaches the ninth month of utero-gestation, its blood is distributed 
 for purification in an organ called the placenta. This placenta, while structur- 
 ally very different from the lungs, accomplishes for the blood of the foetus just 
 
 Right innominate vein 
 
 Vena cava superior 
 Right pulmonary artei~y 
 
 Vena cava inferior 
 
 Left branch of portal vein 
 
 DUCTUS VENOSUS 
 
 Umbilical vein 
 
 Portal vein 
 
 Right bnnifh <>f 
 portal vein 
 
 Umbilical vein 
 
 Umbilical arteries _ 1 
 
 Hypogaitric artery 
 
 Left innominti/p 
 vein 
 
 Arch of aorta 
 
 DUCTUS ARTERIOSUS 
 
 Left pulmonary 
 artery 
 
 Descending aorta 
 
 Superior 
 mesenteric artery 
 
 Inferior 
 mesenteric artery 
 
 Left common iliac 
 artery 
 
 I nt f rnnl i/iui- uri, 
 
 Kill-null /linear/ fry 
 
 ;. 155. THK HKART, WITH TIIK ARCH <>i THK AORTA, TIIK I'ILMONAKY AKTK.KY, 1111 I- 
 
 Al; I I KloSUS, AND THE VESSELS CONCERNED IN TIIK Fd'.TAI. CIRCULATION. 
 (From a preparation of a foetus in the Museum of St. Bartholomew's Hospital.) 
 
 
 the same results as are accomplished by the lungs /vW part cm. The purification 
 of the blood in cither case is in accordance with the law of physics regulating 
 the diffusion of gases. Blood, on entering lung or placenta, is laden with O )._, ; 
 
THE THORAX. 221 
 
 on leaving the same it is laden with O. The difference, then, between the ante 
 partem and post partem purification of blood is not a physiological one ; but a 
 difference is to be found in certain anatomical routes taken by this blood, in the 
 one case to and from the placenta, in the other case to and from the lungs. A 
 study of the metamorphosis of parts after functional activity ceases is replete 
 with interest, since it shows the converse of the law of physiology that growth 
 is the correlation of function. Study the following steps in the foetal circulation, 
 in order that in your dissection you may be able to appreciate the several fcetal 
 vestiges you shall find there. 
 
 1. In the foetus the blood is purified in the placenta of the mother. (Fig. 
 155.) It is taken to that organ by the hypogastric arteries, from the internal 
 iliac arteries. 
 
 2. It is returned from the placenta by the umbilical vein, as follows : (i) To 
 the ascending vena cava by the ductus venosus ; (2) to the portal vein to traverse 
 the liver, and finally reach the ascending vena cava by the hepatic veins. 
 
 3. The blood from above the diaphragm reaches the heart by the descending 
 vena cava, as in the adult. 
 
 4. The blood from the descending vena cava passes through the auricle to 
 the ventricle, and thence out through the pulmonary artery ; the lungs not being 
 yet fitted for purifying, the blood is taken by the ductus arteriosus to the aorta. 
 
 5. The blood from the ascending vena cava passes through the foramen ovale 
 (Fig. 154) to the left auricle, thence to the left ventricle, and out by the aorta. 
 
 The circulatory apparatus of the fcetus possesses : 
 
 1. The umbilical vein brings blood from the placenta. 
 
 2. The hypogastric arteries conveys blood to the placenta. 
 
 3. The ductus venosus takes blood to the vena cava. 
 
 4. The ductus arteriosus connects the pulmonary artery and aorta. 
 
 5. The foramen ovale is an opening between the auricles. All of these 
 structures forming the circulatory apparatus of the fcetus are set aside at birth, 
 when the lungs become the aerating organ for the blood. By non-use these 
 structures lose their specific characters they become obsolete. They obtain in 
 the adult as : 
 
 1. Remains of the umbilical vein, the round ligament of the liver. 
 
 2. Remans of the hypogastric arteries near the urachus. 
 
 3. Remains of the ductus venosus on under surface of liver. 
 
 4. Remains of the ductus arteriosus between aorta and pulmonary artery. 
 
 5. Remains of the foramen ovale in posterior wall of auricle. 
 
 What is a fcetal vestige? The fibrous remains in the adult of an organ that 
 under the conditions of the fcetus in utero was a necessary organ or part. The 
 umbilicus and urachus are foetal vestiges. 
 
 What are the grand divisions of the thorax / 
 
 The thorax may be subdivided into a pulmonary part, occupied by the lungs, 
 and a mediastinal part, not occupied by the lungs. 
 
 Is the word thorax synonymous with trunk / 
 
 No ; thorax is the cavity above the diaphragm ; trunk means the whole body 
 except the head, neck, and extremities. 
 
 Explain the superior mediastinal space. 
 
 This is a space bounded above by the superior aperture of the thorax ; below 
 by a plane limited in front by the manubrio-gladiolar articulation and behind by 
 the body of the fourth thoracic vertebra ; in front by the manubrium ; behind by 
 the four upper thoracic vertebme ; laterally by the pleural sacs. This space 
 
222 
 
 PRACTICAL ANATOMY. 
 
 contains the following structures, which you may find on your work : (i) The 
 thoracic portion of the trachea ; (2) the thoracic portion of the oesophagus ; 
 (3) the thoracic portion of the thoracic duct ; (4) the transverse part of the 
 aortic arch ; (5) the imal and innominate arteries ; (6) the thoracic portion of the 
 left subclavian artery ; (7) the innominate veins, and the superior vena cava ; (8) 
 the terminations of the internal mammary veins ; (9) the terminations of the inferior 
 thyroid veins ; (10) the superior intercostal vein of the left side ; (i i) the two 
 pneumogastric or vagi nerves; (12) the two phrenic and cardiac nerves; 
 (13) the left recurrent or inferior laryngeal nerve; (14) thymus gland in the 
 foetus and remains of the thymus in the adult. 
 
 Describe tJie pericardium. 
 
 It is a fibro-serous sac surrounding the heart. The pericardium is cone- 
 
 Innominate 
 
 Right pulmonary vein 
 
 RIGHT AURICLE 
 RIGHT AURICLE APPENDIX 
 
 Right coronary 
 
 Branch to anterior wall 
 of right ventricle ( pre- 
 ventricular) 
 
 Right marginal artery 
 and vein (vein of Galen) 
 
 Lfft carotid 
 Left subclavian 
 
 Left pulmonary vein 
 
 LEFT AURICULAR APPENDIX 
 
 Left marginal artery 
 
 Anterior intervenlriciilar 
 branch of the great car- 
 diac vein 
 
 Left coronary (interven- 
 tricular) 
 
 Commencing ra<li<-lf.i nf 
 posterior intern- iitrin- 
 ular vein 
 
 FIG. 156. ANTERIOR VIEW OK THE HEART, SHOWING ITS ARTERIES AND VEINS. 
 
 shaped, the base being attached to the central tendon of the diaphragm, tin 
 apex being lost in the fibrous sheath of the vessels that arise from the base o 
 the heart. Structurally the pericardium is inelastic. Above it is continuous 
 with the third layer of deep cervical fascia. The pericardium is attached in front 
 to the sternum by sterno-pericardial bands. 
 
 /'roi/i i^'liat so/tree <loes the pericardium receive its blood-supply / 
 
 From the phrenic below; from the internal mammary in front; from tin 
 oesophagi -al, prricardiac, and bronchial branches of the thoracic aorta behind. 
 
 From u'liat source <jocs (lie pericardium receive its nerve-supply / 
 
 From the phrenic, vagus, and sympathetic. 
 
 Xame the structures at the base of (lie heart that derive Strengthening bands 
 from the pericardium. 
 
THE THORAX. 
 
 223 
 
 The aorta, the pulmonary arteries and veins, the ductus arteriosus. 
 
 What can yon say of the investment of the aorta and pulmonary artery? 
 
 They are invested by a common sheath ; behind these vessels is a passage 
 called the great sinus of the pericardium. 
 
 Name the valves of the heart and the valves of its vessels, and tell hoiv they are 
 formed. 
 
 The coronary, the Eustachian, the aortic and pulmonary semilunar, the right 
 and left auriculo-ventricular. They are formed by folds of endocardium and 
 subserous connective tissue. 
 
 What are the grand divisions of the right auricle / 
 
 The auricular appendix and sinus venosus, or atrium. This auricle forms the 
 front part of the base of the heart. Into the atrium the following structures 
 
 Right carotid artery 
 
 Left carotid artery 
 Left subclavian artery 
 
 Aorta 
 Ductus arteriosus 
 
 Pulmonary artery 
 
 Left pulmonary veins 
 
 LEFT AURICLE 
 
 Left coronary artery 
 
 Left marginal artery 
 
 Oblique vein of Marshall 
 
 Left marginal vein 
 
 PERICARDIUM 
 
 Coronary sinus 
 
 erior cardiac vein 
 
 Poster 
 
 Innominate artery 
 
 \ena cava superior 
 
 Right pulmonary veins 
 RIGHT AURICLE 
 
 Vena cava inferior 
 
 Right coronary artery 
 Posterior intervenlricular vein 
 
 Posterior interventricular branch 
 of right coronary 
 
 Anterior interventricular 
 branch of left coronary 
 
 FIG. 157. POSTERIOR VIEW OF THE HEART, SHOWING ITS ARTERIES AND VEINS. 
 
 open: (i) The descending vena cava; (2) the ascending vena cava; (3) the 
 auriculo-ventricular opening ; (4) the coronary sinus ; (5) the foramina of 
 Thebesii ; the foramen ovale in the foetus. 
 
 What can 'you say of the foramina of Tlicbesius ? 
 
 The most of them are blind sacs. Some are, however, perforate, and return 
 blood from the heart by the venae minimae cordis. The largest vein of this 
 group is called the vein of Galen. You will remember the veins of Galen 
 return the blood from the basal ganglia of the brain to the straight sinus of the 
 dura mater. To be specific in speech, then, speak of the veins of Galen of the 
 brain and of the heart. 
 
 Name the openings in the right auricle having valves. 
 
 The auriculo-ventricular, the coronary sinus, and the ascending vena cava. 
 
224 PRACTICAL ANATOMY. 
 
 Name and give the importance of the openings of the right ventricle. 
 
 The auriculo-ventricular opening, guarded by valves of like name ; the 
 pulmonary opening, at the beginning of the pulmonary artery, guarded by the 
 pulmonary semilunar valves, three in number. 
 
 What are the sinuses of Valsalva and u'/iere do yon find them in practical 
 anatomy / 
 
 They are pouches or dilatations behind the semilunar valves of both the 
 aorta and pulmonary artery. 
 
 What are the c alumna carnece / 
 
 They are muscular columns found in the ventricles of the heart. They are 
 mechanical devices for -strengthening the cardiac walls. They also give a 
 yielding attachment to the auriculo-ventricular valves. 
 
 What are the chordce tcndime / 
 
 Strong, glistening, tendinous threads attached by one extremity to the 
 auriculo-ventricular valves, by the other to the walls of the ventricle by the 
 medium of the columneae carneae. They inhibit the movement of the valve 
 during systole and aid recoil of the valve in diastole of the ventricles. 
 
 Describe the blood-supply of the heart. 
 
 The heart is supplied with blood by two arteries, called the left and right 
 coronary arteries. These arteries arise from the sinuses of Valsalva of the aorta. 
 The left arises from the posterior sinus, the right from the anterior sinus. The 
 auriculo-ventricular grooves and the interventricular grooves are where you 
 will find the main trunks of the arteries that supply the heart. 
 
 Two anastomotic circles, a horizontal and a vertical, corresponding to the 
 grooves separating the auricles from the ventricles, and the ventricles from each 
 other respectively, may be traced out. The right coronary artery divides into 
 two main branches : the horizontal occupies the right auriculo-ventricular groove ; 
 the vertical, the right interventricular groove. The left coronary artery divides 
 likewise into two branches: the horizontal one occupies the left auriculo-ventricular 
 groove, and the vertical the left interventricular groove. In these grooves the 
 opposite arteries anastomose. 
 
 HOT.V is blood returned from the heart / 
 
 Veins called coronary accompany the arteries just described, and open into 
 the right auricle by the coronary sinus, which is guarded by the coronary valve. 
 This opening is between the inferior vena cava and the auriculo-ventricular 
 opening. 
 
ABDOMEN. 
 
 THE ABDOMINAL WALLS. 
 
 Dissection. Locate on the cadaver (i) the ensiform, or metastcrnum ; (2) the 
 sympliysis pubis ; (3) the spine of the pnbcs ; (4) the crest of the pubes ; (5) the 
 crest of the ilium ; (6) the anterior superior iliac spine ; (7) the loiver eight ribs ; 
 (8) the umbilicus; (9) Pouparf 's ligament ; (10) the mid-line of the abdomen. 
 
 The abdominal walls include (i) skin ; (2) superficial fascia; (3) panniculus 
 adiposus ; (4) deep fascia ; (5) the external or descending oblique muscle ; (6) the 
 internal or ascending oblique muscle ; (7) the transversalis muscle ; (8) the rectus 
 abdominis ; (9) the pyramidalis ; (10) the sheath of the rectus; (i i) the trans- 
 versalis fascia; (12) the linea alba; (13) the lineae transversae ; (14) the linese 
 semilunares ; (i 5) peritoneum. 
 
 1 . Define panniculus adiposus. 
 
 The great mass of fat in the upper strata of superficial fascia is thus desig- 
 nated. It is of variable thickness. In it are found the cutaneous vessels and 
 nerves to the skin covering the abdomen. 
 
 2. What can you say of the deep fascia ? 
 
 It is beyond doubt the same as the aponeurosis of the external oblique 
 muscle. The thin fascia described by some authors is not continuous with the 
 fascia lata, nor has it attachments to bone ; hence it must be the deep layer of 
 the superficial fascia. The aponeurosis of the external oblique muscle is continu- 
 ous with the fascia lata ; hence it must represent the deep fascia. 
 
 3. Define linea alba. 
 
 It is in the mid-line, extending from the ensiform cartilage to the symphysis 
 pubis. It is the place where the muscles of the two sides of the abdomen meet. 
 
 4. Hoiv is the sheath of the rectus formed f 
 
 By a delamination or splitting of the aponeurosis ofthe internal oblique muscle. 
 In front of the muscle, then, is the entire thickness of the aponeurosis of the 
 external oblique, and half of the thickness of the internal oblique ; behind the 
 muscle is the entire thickness of the transversalis, and half of the thickness of 
 the aponeurosis of the internal oblique. 
 
 5 . Does the muscle extend through the sheath from end to end in this manner ? 
 No ; it perforates the posterior wall of its sheath midway between the 
 
 umbilicus and the pubic crest, thus leaving, from this point down to the pubic 
 crest, the three aponeuroses all in front of the muscle. 
 
 6. By what name is the lower margin of the posterior part of the sheath of the 
 rectus known ? 
 
 It is called the semilunar fold of Douglas. 
 
 Preparation and Incisions. Make a circular incision through the skin, three 
 inches in diameter, around the umbilicus as the central point. Begin at the cir- 
 cumference and dissect the skin toward the umbilicus for about one inch all 
 around. Now, with a small pair of scissors puncture into the peritoneal cavity 
 through the center of the umbilicus ; insert a tube and inflate the cavity to its 
 
 225 
 
226 
 
 PR A C7ICA L A NA 7 OMY. 
 
 Pectoralis major 
 
 SUPRA CLA VICULAR 
 BRANCH OF 
 CERVICAL PLEXUS 
 
 Pectoralis minor 
 
 - INTERCOSTO- 
 \\ HUMERAL 
 
 Latissimua doisi 
 
 Serratus magnua 
 
 Sheath of rectua 
 
 ANTERIOR 
 CUTANEOUS OF 
 LAST THORACIC 
 
 11:10- 
 
 ILIO-INGTIXM. 
 
 External oblique 
 
 LATERAL CUTANEOUS 
 OF LAST THORACIC 
 NERVE 
 
 158. CUTAM i - NKKVI-.S OK TIIK THORAX AMI ABDOMEN, \II\VI-D i ROM THK SIDK. (Atu-i 
 
 Henle.) 
 
ABDOMEN. 
 
 227 
 
 fullest extent, and let an assistant throw a string about the umbrella of skin just 
 turned upward, and while you withdraw the tube he will tie the cord. The 
 
 Peetoralis major 
 
 Origin of pectoralis 
 
 Major from aponeurosis 
 
 of obliquus externus 
 
 Obliquua externue 
 
 Linea semilunaris 
 
 Tensor vaginae femoria 
 
 Ilio-tibial baud 
 
 TrapeziuB 
 Serratus maguua 
 
 LatissimuB dorsi 
 
 Oluteui maximus 
 
 Tendon of biceps 
 
 FIG. 159. EXTERNAL OBLIQUE AND ILIO-TIBIAL BAND. 
 
 cavity distended in this way, you can proceed properly with your dissection as 
 follows : 
 
 Incisions. (i) Cut from ensiform to symphysis pubis ; (2) cut from umbilicus 
 
228 
 
 PRACTICAL ANATOMY. 
 
 horizontally outward, at right angles to the first incision. Remove the skin care- 
 fully, beginning at the umbilicus. 
 
 Biceps 
 
 Subscapularis 
 
 Pectoralis minor 
 
 Pectoralis major 
 Teres major 
 
 Internal oblique 
 
 Rectus 
 
 PyramidaliB 
 Conjoined tendon 
 
 FIG. 160. Tin-. I'K< IOKAI.IS MINOR, 
 
 INTERNUS, PYRAMIDAI.IS, AND RECTUS ARDOMINIS. 
 
 In this region you will find: (i) The cutaneous branches of the six lower 
 intercostal nerves ; (2) the ilio-hypogastric nerve ; (3) the ilio-inguinal m-r\ v ; 
 
ABDOMEN. 
 
 229 
 
 (4) the spermatic cord with the genital branch of the genito-crural nerve on its 
 posterior surface and the ilio-inguinal nerve in front; (4) you will see also with 
 the above abdominal intercostal nerves some small arteries. They are the lower 
 intercostals and lumbars. 
 
 The nerves you see near the mid-line (Fig. 158) are the terminal branches, 
 while those represented more externally are the lateral cutaneous branches of the 
 intercostals. Search in the fat until you find the point of emergence of the nerve ; 
 then trace out its branches by dividing the connective tissue in the direction of 
 the branches. 
 
 External Oblique (Fig. 159). (i) Dissect the fat and fascia off and expose 
 the muscle as in the figure. At the upper part of the muscle develop the digi- 
 tations of this muscle with the serratus magnus. Trace each digitation to the 
 bone. In developing these origins use the forceps and scissors. (2) Now trace 
 
 Aponeurosis 
 of obliquus 
 externua 
 
 Loops of | 
 eremaster 
 
 Intercolumnar 
 fibres 
 
 FIG. 161. OBLIQUUS EXTERNUS AND FASCIA LATA. 
 
 the muscle downward and forward in the direction of the fibres to the outer lip 
 of the iliac crest. Notice that the muscular fibres disappear at the anterior 
 superior iliac spine, and from this point onward to the mid-line of the abdomen, 
 and downward to the pubes, the muscle is continued as an aponeurosis /. e., 
 the muscle minus the lean meat ! (3) Remove the fat and fascia, and demon- 
 strate the linea semilunaris, the lineae transversae, and the linea alba. The last 
 is in the mid-line. (4) Examine the lower margin of the aponeurosis of this 
 external oblique muscle. It extends in a sagging manner from the anterior 
 superior iliac spine to the pubic spine under the name of Poupart's ligament, or 
 crural arch. This arch is continuous below with the fascia lata of the thigh. 
 (5) Locate the spine of the pubes, and on the under part of the same find the 
 spermatic cord. (Fig. 161.) Trace this cord upward and outward to a point 
 where it enters the external abdominal ring. (Fig. 161.) Above and below the 
 ring, see the pillars or columns of the ring. Notice and develop some transverse 
 
230 
 
 PRACTICAL ANATOMY. 
 
 fibres, called the intercolumnar fibres. (6) Insert the forceps between the pillars 
 just mentioned, parallel to Poupart's ligament, for about two inches. They are 
 now in the inguinal canal. (Fig. 163.) Below them is the floor of the canal, the 
 upper surface of Poupart's ligament, and on this floor is the spermatic cord ; 
 external to them is the outer wall of the canal the aponeurosis of the external 
 oblique muscle ; above them is the roof of the canal the arched fibers of the 
 internal oblique and transversalis muscles ; internal to them is the inner wall of 
 the canal the conjoined tendon of the internal oblique and transversalis muscles 
 and the transversalis fascia. If you gently pull the spermatic cord, you will see 
 where it comes into view. This spot where the cord appears is the internal 
 
 External intercostal 
 
 Internal intercostal 
 
 Posterior portion of 
 sheath of reotua 
 
 Transversalis 
 abdoininis 
 
 Fold of Douglaa 
 
 Iliaous 
 
 Transversalis fascia and 
 internal abdominal ring 
 
 Conjoined tendon 
 
 Poupart's ligament 
 
 Gimbernat's ligament 
 
 Serratua magnus 
 
 Lumbar fascia 
 
 FIG. 162. TRANSVERSALIS ABDOMJNIS AND SHEATH OK RKCTUS. 
 
 abdominal ring in the transversalis fascia. Do not remove the forceps until you 
 
 have re-read (6), i, e., the above geometrical description of the inguinal canal, 
 
 and carefully studied. and learned the following: 
 
 The inguinal canal has the following points : 
 
 1. An external ring in the aponeurosis of the external oblique. (Fig. 161.) 
 
 2. An internal ring in the transversalis fascia. 
 
 3. A floor, the upper inner surface of Poupart's ligament. 
 
 4. A roof, the arched fibres of the internal oblique and transversalis. 
 
 5. An outer ,\v?//, the aponeurosis of the external oblique. 
 
 6. An inner aW/, conjoined tendon, triangular ligament, transversalis fasc 
 
 7. Contents: spermatic cord, male ; round ligament, female. 
 
ABDOMEN. 
 
 231 
 
 8. Extent, from external to internal abdominal ring. 
 
 9. Location of internal ring, one-half of an inch above Poupart's ligament and 
 midway between symphysis pubis and anterior superior iliac spine. 
 
 10. Length of canal, one and one-half inches. 
 
 Having learned the above thoroughly, cut through the external wall and 
 expose the canal, as in figure 161. 
 
 Coverings of the Spermatic Cord and Testicle. Pass your finger down 
 into the scrotum anterior to the cord ; cut through the skin and fascia and 
 expose the testicle and find the following coats : 
 
 1. The skin and superficial fascia. 
 
 2. The dartos, consisting of muscular and contractile tissue. 
 
 3. The intercolumnar fascia, part of external oblique. 
 
 4. The cremasteric fascia, part of the internal oblique. 
 
 5. The infiindibuhnn, part of transversalis fascia. 
 
 6. The tunica vaginalis, part of the peritoneum. 
 
 You will then look upon these coats as small parts of the individual con- 
 stituents of the abdominal walls pushed ahead of the testicle in its descent. 
 The tunica vaginalis was pushed ahead, a part of the peritoneum ; the infundi- 
 bulum, a part of the transversalis fascia; the cremaster, apart of the internal 
 oblique ; the intercolumnar fascia, a part of the external oblique ; the dartos, a 
 part of the superficial fascia, slightly modified by the presence of elastic fibres 
 and muscle fibres ; the skin to form the scrotum. 
 
 The Spermatic Cord. In front of the cord find the ilio-inguinal nerve ; be- 
 hind the cord the genital branch of the genito-crural nerve. Find the excretory 
 duct of the testicle the vas deferens ; the spermatic artery, a branch of the 
 aorta ; the spermatic veins ; a little artery the deferential in the sheath of the 
 vas deferens. These structures are all bound loosely together by connective 
 tissue. You will trace all these structures to the testicle. 
 
 Next expose the internal oblique muscle by turning aside the external ob- 
 lique in this manner : Divide the digitations at their attachments into the eight 
 lower ribs. Turn the whole muscle forward and see the internal oblique. Its 
 fibres run upward and inward. This is also called ascending oblique. 
 
 The Internal Oblique (Fig. 160). This muscle has attachments : (i) To 
 the outer surface of the four lower ribs ; (2) to the middle lip of the crest of the 
 ilium ; (3) to the outer one-half of Poupart's ligament ; (4) to the pubic crest 
 and ilio-pectineal line ; (5) to the linea alba. Notice, first, the arch formed by this 
 muscle and the transversalis. In figure 160 you see these muscles are attached 
 to Poupart's ligament for about the outer one-half the length of this ligament; 
 then they leave this ligament, arch over the cord, form the roof of the inguinal 
 canal, and are inserted into the pubic crest by the conjoined tendon. Trace this 
 muscle to the middle lip of the iliac crest, anterior two-thirds. 
 
 Make an incision, parallel to the iliac crest, through this muscle, and you will 
 come down upon the neuro-vascular area of the abdominal walls. These vessels 
 and nerves are between the internal oblique and transversalis, in a small quantity 
 of fatty connective tissue, and are as follows : 
 
 1. Deep circumflex iliac artery, from the external iliac. 
 
 2. Ilio-hypogastric nerve, from the lumbar plexus. 
 
 3. Ilio-inguinal nerve, from the lumbar plexus. 
 
 4. Lower intercostal nerves, the twelfth thoracic. 
 
 It will require care to separate these muscles. The guide is this : Keep the 
 nerves in sight and follow them. Now trace the internal oblique muscle to the 
 outer surface of the four lower ribs. Notice the direction taken by the muscular 
 fibres. See also that the fibres of this muscle are attached to the outer one-half 
 of Poupart's ligament, with the transversalis, and that both are inserted by a 
 
232 PRACTICAL ANATOMY. 
 
 conjoined tendon into the pubic crest and ilio-pectineal line for a variable dis- 
 tance. 
 
 The transversalis muscle is now fully exposed to view. (Fig. 162.) On 
 its outer surface you see the plexus of nerves and the vessels previously described. 
 On its inner surface you will find the transversalis fascia. The fibres of this 
 muscle extend transversely across the wall. The muscle arises (i) from the 
 inner surfaces of the six lower ribs, interdigitating with the diaphragm ; (2) from 
 the lumbar fascia ; (3) from the inner lip of the iliac crest ; (4) from the outer 
 two-thirds of Poupart's ligament. The muscle is inserted into (i) the lineaalba ; 
 (2) the crest of the pubes ; (3) the ilio-pectineal line. This muscle assists the 
 internal oblique in forming the arch and the conjoined tendon. 
 
 FIG. 163. INTERNAL OBLIQUE AND TRANSVERSALIS ABDOMINIS MUSCLES. 
 
 I, I. Rectus abdominis. 2, 2. Internal oblique. 3, 3. Anterior leaflet of aponeurosis of internal oblique. 
 4, 4. Divided external oblique. 5, 5. Spermatic cords. 6, 6. Inferior portion of aponeurosis of 
 external oblique. 7. Lower portion of left rectus abdominis; upper portion removed. 8,8. Mus- 
 cular portion of transversalis abdominis. 9. Aponeurotic portion, to. Umbilicus. II. Supra 
 umbilical portion of linea alba. 12. Infra-umbilical portion. 13. Senatus magnus. 14. Divided 
 right latissimus dorsi. 15- Divided left latissimus dorsi. 16. Divided serratus magnus. 17, 17. 
 External intercostals. 18, 18. Femoral aponeurosis. 19. Divided internal oblique. 
 
 The Rectus and Pyramidalis. Make an incision through the sheath of 
 the rectus, extending from the pubic spine to the fifth rib, parallel with the linea 
 alba. Carefully dissect the sheath both ways /. c., turn the sheath to the right 
 and left until you have fully exposed the muscular contents. (Fig. 160.) The 
 white lines crossing the rectus are the linear transverse. You will find the pyra- 
 midalis below, arising from the pubic crest in front of the rectus. Trace it to its 
 insertion into the linea alba. (Fig. 160.) Now you can easily lift the rectus from 
 its bed, and look down on the posterior part of its slie.ith. (Fig. 163.) A descrip- 
 tion of the formation of the sheath is given in the beginning of this section. Cut 
 through the rectus one inch below the umbilicus and see : (i) The deep epigastric 
 artery and its veins ; (2) the sanilniiar fold <>/' /) t >ttg/ds. Turn the divided ends 
 of the rectus aside and trace out the branches of the deep epigastric artery. 
 
 
ABDOMEN. 233 
 
 Hesselbach's triangle is of surgical importance because direct inguinal hernia 
 passes through it. (Fig. 165.) It is bounded internally by the rectus, externally by 
 the deep epigastric artery, below by Poupart's ligament. See, now, that the con- 
 joined tendon of the internal oblique and transversalis stretches across the inner 
 two-thirds of this triangle. Hence this tendon may become one of the coverings 
 of a direct inguinal hernia. 
 
 1 . Points of surgical interest. 
 
 The inguinal canal, since, physiologically, it transmits the male spermatic cord 
 and its homologue, the round ligament of the uterus ; since, pathologically, in- 
 guinal hernia and diseases of the cord are interrogated here. 
 
 2. Importance of tlie umbilictts. 
 
 This is a physiological cicatrix or scar, marking the aperture through which 
 passed the vessels that made up the umbilical cord, or funis, in the child before 
 birth. These vessels were the right and left hypogastric arteries (branches of the 
 internal iliacs) and the umbilical vein. The arteries took blood to the placenta 
 for aeration ; the vein returned this blood aerated. You will find internally in 
 adult dissections remains of these three vessels centering at the umbilicus. 
 
 3 . Further importance of umbilicus. 
 
 In both adult and child it may be the location of umbilical hernia. 
 
 4. Give nerve-supply of the abdominal muscles. 
 
 The six lower thoracic nerves, through their anterior primary divisions, 
 assisted by the ilio-hypogastric and ilio-inguinal nerves from the lumbar plexus. 
 They also supply the skin covering these muscles. 
 
 5 . Give the blood-supply of the abdominal ivalls. 
 
 This is both abundant and important, (i) The deep epigastric ; (2) the internal 
 mammary ; (3) the lumbar arteries ; (4) the intercostals ; (5) the deep circum- 
 flex iliac ; (6) the superficial circumflex iliac ; (7) the superficial epigastric. The 
 deep epigastric, a branch of the external iliac, anastomoses in the substance of 
 the rectus muscle with the superior epigastric branchof the internal mammary 
 artery, a branch of the subclavian artery. 
 
 6. Function of abdominal muscles. 
 
 (i) They protect from violence and temperature changes the organs in the 
 abdominal cavity ; (2) they assist internal organs to discharge their contents, in 
 that they excite peristalsis a physiological Crede ; (3) they, by their various 
 contractions, alter the relations between the thorax and abdomen ; (4) they are 
 strongly analogous to structures above the diaphragm. The external oblique is 
 analogous to the external intercostals ; the internal oblique to the internal inter- 
 costals ; the transversalis to the triangularis sterni ; the rectus to the sternum ; 
 the linese semilunares to the chondra, vertically ; the lineae transversae to the cos- 
 tal cartilages ; their nerve- and blood-supply are strongly analogous, while func- 
 tions conform to local demands and structure is modified accordingly. 
 
 Important Attachments and Relations. Notice carefully the following, and 
 demonstrate on your dissection the following points : 
 
 1. Each of the three broad muscles has (i) an outer muscular part, and (2) 
 an inner aponeurotic part ; the latter are inseparably united, the former may be 
 separated from each other. 
 
 2. The conjoined aponeuroses of all three planiform muscles form the verti- 
 cal mid-line of the abdominal walls, known as linea alba abdominis. 
 
 3. The two inner muscles are attached to the upper surface of Poupart's 
 ligament for about one-half the length of this (the outer one-half), and then leaving 
 the same arch over the spermatic cord, forming the roof of the inguinal canal, and 
 are inserted into the pubic crest and inner part of the ilio-pectineal line. 
 
 4. Between the muscular parts of the internal oblique and transversalis 
 muscles is located a meagre plexus of nerves, from which the abdominal muscles 
 
 16 
 
234 PRACTICAL ANATOMY. 
 
 are supplied. The deep internal circumflex artery and its veins are also found 
 here. 
 
 5 . Give the origin and insertion of the external oblique. 
 
 Origin. The outer surface of the eight lower ribs about their middle by a 
 series of nearly horizontal lines which, after crossing each rib obliquely down- 
 ward and backward, extend for a short distance along its lower border. 
 
 Insertion. (i) By a strong aponeurosis along the whole of the linea alba; 
 
 (2) the front of the os pubis close to the symphysis ; (3) the spine of the pubes 
 and the adjacent part of the ilio-pectineal line ; (4) the deep fascia of the thigh 
 in a thickened band which stretches from the spine of the pubes to the anterior 
 superior spine of the ilium ; (5) the anterior half of the outer lip of the crest of 
 the ilium ; (6) at the lower part of the linea alba some of the fibres (the trian- 
 gular fascia] stretch across the middle line, and are inserted into the front of the 
 crest of the pubes and the inner part of the ilio-pectineal line of the other side. 
 
 6. Give origin and insertion of internal oblique. 
 
 Origin. (i) The outer half of Poupart's ligament ; (2) the anterior two-thirds 
 of the space intervening between the inner and outer lips of the crest of the ilium ; 
 
 (3) the outer and posterior aspect of the aponeurosis of the transversalis abdom- 
 inis (which aponeurosis is also called the lumbar fascia). 
 
 Insertion. (i) For about one inch into the inner extremity of the ilio-pecti- 
 neal line ; (2) the anterior border of the crest of the pubes ; (3) the whole length 
 of the linea alba ; (4) the lower borders of the cartilages of the last three ribs. 
 
 7. Give origin and insertion of transversalis. 
 
 Origin. (i) The inner surface of the cartilages of the last six ribs, close to 
 their junction with the ribs, by processes which interdigitate with the attachments 
 of the diaphragm ; (2) the strong aponeurosis called the lumbar fascia, which arises 
 (a) by its anterior layer from the front of the transverse processes of the five 
 lumbar vertebrae, (^) by its middle layer from the tips of the transverse processes 
 of the five lumbar vertebrae, (c] by its posterior layer from the general vertebral 
 aponeurosis which is attached to the spines of the thoracic, lumbar, and sacral 
 vertebrae ; (3) the anterior two-thirds of the inner lip of the crest of the ilium ; 
 
 (4) the outer third of Poupart's ligament. 
 
 Insertion. (i) The whole length of the linea alba ; (2) the anterior border of 
 the crest of the pubes ; (3) the inner end of the ilio-pectineal line for about one 
 inch and a half. 
 
 8. Give origin and insertion of the rectus. 
 
 Origin. By two tendons: (i) The larger or outer head arises from the 
 whole of the crest of the pubes ; (2) the inner head crosses the middle line of 
 the body, and arises from the fibrous structures lying in front of the symphysi> 
 pubis. 
 
 Insertion. (i) The anterior surface of the tip of the fifth rib ; (2) the front ot 
 the costal cartilages of the fifth, sixth, and seventh ribs ; sometimes also (3) th< 
 deep posterior surface of the ensiform cartilage near its outer border. 
 
 Anatomy of Inguinal Hernia. There are two varieties of inguinal hernia, 
 founded on the idea of internal to or external to the deep epigastric artery, a 
 structure already seen in your dissection. The name direct inguinal is given 
 when a hernia comes through Hesselbach's triangle. In this case the coverings 
 are: (i) Peritoneum ; (2) transversalis fascia ; (3) conjoined tendon; (4) inter- 
 columnar fascia ; (5) superficial fascia ; (6) skin. The name oblique is given 
 when the hernia enters the canal by the internal abdominal ring, in the transver- 
 salis fascia, external to the deep epigastric artery. It has these coats : (i) Peri- 
 toneum ; (2) subserous fatty connective tissue ; (3) infundibulum ; (4) cremasteric 
 muscle; (5) intercolumnar fascia ; (6) superficial fascia ; (7) skin. This variety 
 of hernia follows the course taken by the testicle in its descent, and receives the 
 
ABDOMEN. 
 
 235 
 
 same kind of investments. As before stated, these coats are simply certain parts 
 of the walls which have receded before the hernia in its descent. 
 
 Describe tJic ilio-liypogastric nerve. 
 
 It is a branch of the lumbar plexus. It is known also as the superior mus- 
 culo-cutaneous nerve. It crosses the quadratus lumborum muscle, gains the 
 space between the transversalis and internal oblique muscles, and divides into (i) 
 an iliac branch, which supplies the skin over the gluteal region ; (2) a terminal 
 hypogastric branch, that passes between these two muscles i. c\, the internal 
 oblique and transversalis to near the mid-line, where it comes through the 
 abdominal walls an inch above the external abdominal ring. 
 
 Describe the ilio-inguinal nerve. 
 
 You find this nerve anterior to the spermatic cord. It is distributed to the 
 
 Epigastric artery 
 
 Internal abdom- 
 inal ring 
 
 Border of the 
 posterior part 
 of the sheath 
 of the reetus 
 (fold of Doug- 
 las) 
 
 Posterior surface 
 of reetus 
 
 'Jjitf Conjoined tendon 
 
 in the triangle 
 
 of Hesselbach 
 Obliterated hypo- 
 gastric artery 
 Lymphatics in 
 crural rings 
 
 External iliac artery 
 
 FIG. 164. DISSECTION OF THE LOWER PART OF THE ABDOMINAL WALL FROM WITHIN, THE PERI- 
 TONEUM HAVING BEEN REMOVED. (Wood.) 
 
 scrotum and labia majora, and to the inner and upper part of the thigh. It is a 
 branch of the lumbar plexus. It runs near to and plexifies with the preceding 
 nerve, between the internal oblique and transversalis. 
 
 Describe t/te genilo-crural nerve. 
 
 This is seen behind the spermatic cord, in the canal ; after the cord emerges 
 from the external abdominal ring, the genital branch of the genito-crural nerve is 
 seen behind the cord. This supplies the cremaster muscle with motion. The 
 crural branch of the genito-crural nerve goes to the skin over the mid-front of 
 the thigh half way to the knee. 
 
 INTERIOR VIEW OF ABDOMINAL WALLS. 
 
 Make an incision on each side, from the lower part of the umbilicus to the 
 anterior superior spine of the ilium, through the entire remaining abdominal wall. 
 Turn the V-shaped flap thus formed forward, and at the same time lift it upward 
 
236 PRACTICAL AX A TO MY. 
 
 and put it on the stretch as much as possible. You are to see and study the 
 following structures through the peritoneum (do not remove this yet) : 
 
 1. The plica urachi a peritoneal fold covering the remains of the urachus. 
 This is in the mid-line from the summit of the bladder to the umbilicus. 
 
 2. The plica hypogastrica, covering the remains of the hypogastric arteries. 
 
 3. The deep epigastric arteries and veins, passing upward and inward to 
 enter the sheath of the rectus muscle by passing under the fold of Douglas. 
 
 4. Poupart's ligament and the external iliac vessels leaving the pelvis, to 
 be called femoral in the thigh. Here, too, see the external iliac artery giving oft" 
 its two branches, the deep epigastric and the internal circumflex iliac branch. 
 
 5. The internal abdominal ring, to which you may see plainly the con- 
 stituents of the spermatic cord coming viz., the vas deferens, the spermatic 
 vessels. Locate this ring just to the outer side of the deep epigastric artery. 
 
 6. The femoral canal, called also crural canal. Find this to the inner side 
 of the femoral vein, between Poupart's ligament above and the bone below. To 
 its inner side you will feel the sharp falciform margin of Gimbernat's ligament. 
 This canal is in the femoral sheath, and occupied by fat and connective tissue 
 called the septum crurale or septum femorale. 
 
 7. Inguinal and Femoral Fossae. There are three of these. The internal 
 is between the remains of the urachus and hypogastric artery ; the middle inguinal 
 fossa is between the remains of the hypogastric artery and the deep epigastric 
 artery. The importance of these two fossae is they permit direct inguinal 
 hernia to form. The external inguinal fossa is external to the deep epigastric 
 artery and corresponds to the situation of the internal abdominal ring, and is the 
 location of oblique inguinal hernia. In this connection notice the femoral fossa. 
 This corresponds to the femoral ring, and marks the location of femoral hernia. 
 
 DISSECTION OF FEMORAL HERNIA. 
 
 Find the femoral fossa, covered by peritoneum, just below Poupart's liga- 
 ment, and internal to the femoral vein. Now remove the peritoneum, by pulling 
 the same gently backward and downward. Take the forceps and break up the 
 connective tissue in the femoral canal, the depression corresponding to the 
 femoral fossa just mentioned and internal to the femoral vein. We will consider 
 femoral hernia with reference to (i) the femoral sheath ; (2) the femoral canal ; (3) 
 the coverings of femoral hernia ; (4) contents of the canal ; (5) the relations to 
 other structures ; (6) anatomical factors concerned in reduction ; (7) the deep 
 crural arch. 
 
 The femoral sheath is formed under Poupart's ligament by the meeting 
 and union of the fascia transversalis in front of the femoral vessels and of the iliac 
 fascia behind the femoral vessels. As you will demonstrate on your cadaver, these 
 fasciae unite on the outer side of the femoral artery very close to the vessel ; on 
 the inner side of the vein, however, they leave an interval, one-half of an inch in 
 width, between the femoral vein and Gimbernat's ligament. (Fig. 165.) This 
 interval is the femoral canal. 
 
 The deep crural arch extends in an archiform manner across the femoral 
 sheath, strengthening thereby the transversalis fascia. It is inserted into the 
 spine of the pubes, and may be looked upon as a slip of contribution from the 
 transversalis fascia. 
 
 The femoral sheath contains the following structures : ( i) The femoral arte 
 on the outer side; (2) the femoral vein in the middle: (3) the femoral can 
 internal to the vein. The beginning of the femoral canal not the beginning o 
 the sheath is the femoral ring. The femoral canal contains some connective 
 tissue that you just broke up with your forceps. The special name for this is 
 
the septum femorale or septum crurale. Make note of this, for it forms one of 
 the coverings of femoral hernia. I wish to make emphatic the difference nou 
 between the contents of the femoral sheath and the contents of the femoral canal. 
 The canal itself is in the sheath. 
 
 The femoral ring and its relations are the beginning of the femoral canal, 
 just as the brim is the beginning of a cup. The ring has certain definite bounda- 
 ries and relations, which you must both demonstrate on your work and commit 
 thoroughly to memory. In figure 165 you can study these. Internal to the 
 ring is the sharp falciform edge of Gimbernat's ligament. This, as you can easily 
 demonstrate on your work, is a reflection of Poupart's ligament on to the ilio- 
 pectineal line. To the outer side of the ring is the femoral vein. Above the 
 
 Deep circumflex iliac artery 
 
 External iliac artery 
 External iliac vein 
 
 Obturator foramen 
 
 B 
 
 Internal ring, with spermatic 
 vessels cut short in it 
 
 Deep epigastric artery 
 
 Lymphatic gland in femoral 
 ring 
 
 The obturator artery, given off" 
 from the external iliac with the 
 deep epigastric, descends to gain 
 the obturator foramen, but at a 
 safe distance from the femoral 
 ring 
 
 The obturator artery, coming off" 
 from the deep epigastric, HUM 
 a course so near to the femoral 
 ring that it would very likely 
 be divided by the bistoury intro- 
 duced front without to diritlr-. 
 the base of Gimbernaf's liga- 
 ment, the cause of the constric- 
 tion 
 
 FIG. 165. IRREGULARITIES OF THE OBTURATOR ARTERY. (After Gray.) 
 
 ring is Poupart's ligament. Below the ring is the horizontal part of the os pubis, 
 covered by the pectineus muscle and its aponeurosis. You will also see the deep 
 epigastric artery arising from the femoral artery and passing upward and inward 
 across the upper part of the femoral ring. In a certain number of cases the 
 deep epigastric artery gives off the obturator artery, which passes either to the 
 outer side of the ring, as in A, figure 165, or to the inner side, as in B. In 
 either case it would complicate an operation for reduction of femoral hernia. 
 You will note on the cadaver that the obturator artery and nerve lie on the 
 
2 3 8 
 
 PRACTICAL ANATOMY. 
 
 outer wall of the pelvis. The artery is, as a rule, a branch of the internal iliac. 
 It forms an exception to the rule in the figures given here. 
 
 The coverings of femoral hernia from within outward are: (i) The perito- 
 neum ; (2) the subperitoneal connective tissue ; (3) the septum femorale ; (4) the 
 femoral sheath ; (5) the cribriform fascia the deep layer of superficial fascia that 
 covers the saphenous opening in the fascia lata ; (6) the superficial fascia ; (7) the 
 skin. 
 
 Factors concerned in reduction of hernia are those that tend to tighten the 
 canal. These are : (i) The saphenous opening ; (2) the iliac and pubic portions 
 of the fascia lata ; (3) the external oblique muscle and its lower portion Pou- 
 part's ligament. These structures that tend to strengthen a succession of ana- 
 tomical weak points, determining the course of a femoral hernia, may all be dis- 
 empowered by flexion of the thigh on abdomen ; flexion of leg on thigh ; adduc- 
 tion of thigh. Demonstrate this on your work by placing your finger in the 
 femoral canal, and let an assistant produce first abduction and extension, and 
 adduction and flexion, when the scissor-like action of Poupart's and Gimbernat's 
 will be appreciated. 
 
 THE PERITONEUM. 
 
 The inquisitive student instinctively asks himself the following simple ques- 
 tions, which I will here answer fully enough for dissecting-room purposes : 
 i . What kind of a structure is peritoneum and ivhere is it fou)id / 
 Peritoneum is a serous membrane found in the abdominal cavity only. 
 
 LACTEALS 
 
 Veins 
 
 FIG. 166. VESSELS OK THE SMALL INTESTINE. 
 
 2. What is the appearance of peritoneum ami Jiow may I recogitize /// 
 Peritoneum is smooth, moist, glistening. You can recognize it by its loca- 
 tion and its appearance. Its most distinctive feature is its location in the abdom- 
 inal cavity ; removed from this cavity you could not distinguish it from other 
 
 erous membranes pleura and pericardium. 
 
 3. \Vliere will f sec peritoneum on opening the abdominal cavity / 
 
 You will see it forming the innermost layer of the wall you cut and turned 
 
ABDOMEN. 
 
 2 39 
 
 back smooth, moist, glistening, and attached ; you will see it covering every 
 organ in the abdominal cavity partially or completely. If by force of circum- 
 stance organs lose all or some of their peritoneal covering, this is no fault of the 
 peritoneum. Remember, the primitive relation of every organ to peritoneum is 
 behind partially or completely covered thereby. (Figs. 167 and 168.) 
 
 Figure 167 shows aorta giving three branches to three organs. The organ in 
 the centre is for practical purposes completely invested by peritoneum. Between 
 the two parts of the peritoneal fold is (i) The organ ; (2) the vessels that take 
 blood to and from the organ ; (3) the nerves that innervate the organ ; (4) the 
 
 VISCERAL LAYER OF PERITONEUM 
 
 PERITONEAL CAVITY 
 
 PARIETAL LAYER OF PERITONEUM 
 
 KIDNEY AND ITS RENAL VESSELS 
 
 The aorta 
 
 FIG. 167. SHOWING PARTIAL AND COMPLETE INVESTMENT OF ORGANS BY PERITONEUM. 
 
 lymphatics that scavenger the organ. The organ has only one place where it is 
 accessible only one communication with the wall. 
 
 Examine the cadaver, take up a portion of the small intestine, find the 
 superior mesenteric artery, and trace it down between its two parts of the peritoneal 
 folds. Now, with your forceps, make a rent in one side of the mesentery, examine, 
 and find an artery, a vein, nerves, glands, and fat, as represented in figure 166. 
 
 4. Explain implantation of meso-structures. 
 
 That part of the alimentary canal which remained in its original mid-line of 
 the body as the greater part of the small intestine and rectum may be said to 
 be an example of primitive implantation ; those parts which contracted adhesions 
 
 PARIETAL LAYER OF PERITONEUM 
 
 PERITONEAL CAVITY 
 
 The. aorta 
 
 FIG. 168. SHOWING RETRO-PERITONEAL LOCALITY. 
 
 to localities other than the mid-line, may be said to be examples of acquired 
 implantation. The colon and duodenum are examples of this latter variety. 
 
 5. From ivliat source does the peritoneum derive its blood-supply f 
 
 It will be presently seen that the abdominal aorta has parietal branches and vis- 
 ceral branches. The parietal branches, as the lumbar and phrenics, supply the peri- 
 toneum covering these walls ; the visceral branches supply the peritoneum cover- 
 ing the organs. Peritoneal arteries are, then, of two classes visceral and parietal. 
 
 6. Explain peritonea! investment of organs. 
 
240 
 
 PRACTICAL ANATOMY. 
 
 This is as follows : (i) Organs may simply be behind the peritoneum, as arte- 
 ries and veins, in which case we say they are covered by this membrane. (Fig. 
 1 68.) They have not grown sufficiently in thickness to produce any appreciable 
 displacement of the peritoneum. Figure 168 shows the aorta behind the peri- 
 toneum, but producing no bulging forward of the peritoneum. (2) Organs may 
 produce appreciable bulging forward, as in figure 167, when we say they a im- 
 partially invested. Now examine the kidney and you will find its relation to the 
 peritoneum represented in figure 167 in the two organs on the two sides. 
 
 7. What determines the degree of peritoneal investment f 
 
 The height to which any organ grows determines this. The peritoneum 
 pushed ahead of the organ is called the mesentery of the organ and the peritoneal 
 investment. Mesenteries may be long or short. The height to which an organ 
 
 PARIETAL LAYER OF PERITONEUM 
 
 The aorta 
 
 FIG. 169. 
 In this figure an organ has grown to a considerable height and a long mesentery is the result. 
 
 PARIETAL PERITONEUM 
 VISCERAL PERITONEUM 
 
 The aorta 
 FIG. 170. 
 
 In this figure, a is an organ completely invested by peritoneum. Its mesentery grows high and falls on />, 
 an organ partially invested by peritoneum. At the contact point of a and b loss of epithelium occurs. 
 Parts of organs, or entire organs, which once possessed peritoneal investment, but subsequently lost 
 the same in this manner, are said to be retro-peritoneal, or to have no peritoneal investment. An 
 example is to be seen in the case of the right kidney, where the duodenum and colon bear the above 
 relation (Fig. 170) to the anterior surface of this organ. 
 
 grows determines, then, both the degree of investment and the length of the 
 mesentery. 
 
 8. H&W arc the abdominal muscles classified? 
 
 As vertical and horizontal. The pyramidalis and rectus abdominis are ver- 
 tical ; the external and internal oblique and the transversalis are horizontal. 
 
 9. Xamc the abdominal -iccak points in tlic trails of tlic abdominal cavity and 
 give their practical importance in surgery. 
 
 (i) The inguinal canal, limited internally by the internal abdominal ring, and 
 externally by the external abdominal ring. This canal lodges the spermatic cord 
 of the male and the round uterine ligament of the female. It is the succession 
 of weak points that formed the line of least resistance to the descending testicle. 
 
ABDOMEN. 241 
 
 This canal acquires surgical importance in inguinal hernia, of which there are two 
 arbitrary divisions direct and oblique : the former being internal to, the latter 
 being external to, the deep epigastric artery. 
 
 (2) The femoral canal, being that part of the initial three-quarters of an inch 
 of the femoral sheath unoccupied by the femoral vessels. (Fig. 165.) Normally, 
 the canal is occupied by a fatty connective tissue, with or without a lymphatic gland. 
 The entire amount of this connective tissue called technically the septum crurale, 
 or septum femorale weighs three grains. The surgical importance of this septum 
 is due to the fact that it is inferred to form one of the coverings of a femoral hernia. 
 Just why rational medical literature should continue to dignify this frail structure, 
 and place it in the same category with such structures as Gimbernat's and Pou- 
 part's ligaments, the femoral sheath, and the skin itself, is difficult to determine. 
 
 (3) The umbilicus is the point where the two hypogastric branches of the inter- 
 nal iliac arteries and the umbilical vein came together to form the umbilical cord, 
 a foetal arrangement that took impure blood to the placenta and returned in its 
 stead the same blood plus O and minus CO 2 . 
 
 10. Where is the spermatic cord made up and of what structures does it consist ? 
 
 It is made up at the internal abdominal ring, to the outer side of the deep 
 epigastric artery, by the coming together of the spermatic artery, the spermatic 
 veins, the deferential artery, and the excretory duct of the testicle the vas 
 
 PARIETAL PERITONEUM 
 
 VISCERAL PERITONEUM 
 
 MESENTERIC MARGIN 
 CAVITY OF PERITONEUM 
 MESENTERIC STALK 
 
 MESENTERIC ROOT 
 
 The aorta 
 
 FIG. 171. SHOWING SIMPLE VISCERAL AND PARIETAL LAYERS OF PERITONEUM WITH CAVITY 
 
 BETWEEN THEM. 
 
 deferens. These structures are loosely bound together by connective tissue. In 
 practical dissection the cord is found below and external to the pubic spine, not 
 as a cord, but as a flattened band. The cord lies on the shelved inner and upper 
 part of Poupart's ligament, in the inguinal canal. The function of the spermatic 
 artery is to supply the testicle with blood, from which the testicle secretes semen. 
 The spermatic veins return the blood to the general circulation, the right being 
 tributary to the ascending vena cava, the left to the left renal vein. The vas is 
 the conduit that leads the semen to the vesiculae seminales at the base of the 
 bladder. The artery of the vas nourishes this conduit and inosculates with the 
 spermatic artery. 
 
 1 1 . Tell all you can about tJie femoral sheath. 
 
 It is composed of two fasciae that come down out of the abdominal cavity, 
 one in front of and the other behind the femoral vessels. These fasciae surround 
 the vessels and take the name "femoral sheath." 
 
 1 2. What are the fascia t/iat form the femoral sheath and why are they so 
 called? 
 
 The one in front of the femoral vessels is the transversalis ; the one behind the 
 vessels, the iliac fascia. They are named in accordance with the rule governing the 
 naming of deep fasciae i. c., according, in this case, to the name of the muscles. 
 
2 4 2 PRACTICAL ANATOMY. 
 
 13. Do the lumbar arteries assist in furnishing the peritoneum with blood / 
 Yes ; the same arteries that supply the walls, supply the peritoneum cover- 
 ing the walls. 
 
 14. What can you say of the lumbar arteries f 
 
 They are four in number on each side. They are analogous to the intercos- 
 tal arteries. They arise from the abdominal aorta. The right are longer than 
 the left lumbar arteries. These arteries are small when compared to their homo- 
 logues, the intercostals. The lumbar arteries lie behind the abdominal sympa- 
 thetic chain. According to their distribution, the lumbar arteries are classified 
 as dorsal branches and abdominal branches. Each has specific relations and 
 course. The dorsal branches pass out between the transverse processes of the 
 lumbar vertebrae, with the posterior primary divisions of the lumbar nerves, and 
 attended by their corresponding lumbar veins, to be distributed to the spinal 
 cord, passing through the intervertebral foramina; to the muscles and skin of the 
 back ; and to the lumbar vertebrae in this region. The abdominal branches of the 
 lumbar arteries pass behind the sympathetic chain and behind the quadratus lum- 
 borum muscle. They are distributed to the quadratus lumborum and psoas 
 magnus muscles and to the abdominal walls. 
 
 I 5 . What can you say of the anastomosis of the lumbar arteries / 
 The dorsal branches anastomose with each other and with the intercostals. 
 The abdominal branches of the lumbar arteries anastomose : (i) Above with the 
 lower intercostal arteries ; (2) below with the ilio-lumbar and circumflex iliac ; 
 (3) in front with the epigastric and internal mammary. 
 
 1 6. If the abdominal aorta were ligated just above the bifurcation, how could 
 the blood reach the loiuer extremities ? 
 
 Through two channels: (i) The epigastro-mammary arch ; (2) the lumbo- 
 circumflex anastomotic arch. 
 
 17. Describe the epigastro-mammary anastomotic arch. 
 
 An arch formed by anastomosis between the deep epigastric artery, a branch 
 of the external iliac, and the internal mammary artery a branch of the subclavian. 
 This union occurs in the rectus abdominis muscle. 
 
 1 8. Describe the lumbo-circumflcx anastomotic arch. 
 
 It is an arch formed by anastomosis between the lumbar arteries, branches 
 the abdominal aorta, and the deep internal circumflex iliac artery a branch of th< 
 external iliac. 
 
 The arteria sacra media is the sacral representative of the lumbar arteries. It 
 is to the aorta what the coccyx is to the vertebral column, what the ensiform car- 
 tilage is to the sternum the exhaustion. It is the representative of the caudal 
 artery of some animals. Its small branches are distributed in the same manner 
 as those of the lumbar region. 
 
 19. What can you say of the lumbar veins f 
 
 They accompany the lumbar arteries arid are tributary to the ascending \vn; 
 cava. 
 
 20. How would you explain the nerve-supply of the peritoneum / 
 
 The same nerves that supply muscles that enclose a serous cavity supplj 
 the serous membrane enclosed. This principle was pointed out by Hilton am 
 Van der Kolk. The full law, as given previously, applies not only to serous 
 but to mucous membranes as well. 
 
 21. What are the functions of peritoneum f 
 
 It secretes serum for lubrication of opposed surfaces. It is a highly absorp- 
 tive structure. It forms ligaments for holding organs in place. It protect 
 organs against violence. It gives strength to organs which it invests. It con 
 serves heat and piwrnts sudden changes of temperature. 
 
 22. Is serum ever secreted in abnormally large quantities f 
 
ABDOMEN. 
 
 243 
 
 Yes, and the terms by which such conditions are designated are hydro-pericar- 
 dium, hydro-thorax, hydro-cephalus, and hydro-peritoneum. 
 
 23. What is a peritoneal cavity f 
 
 The space between the visceral and parietal layers ot the peritoneum. The 
 same is true of any serous cavity viz., it is the space between a visceral and a 
 parietal layer of serous membrane. 
 
 24. What do we understand by mesenteric contents ? 
 
 All the structures between the two surfaces or folds of the mesentery /. e. , 
 in the mesenteric space. The intestine is, of course, the largest structure. (Fig. 
 1 66.) The vessels, nerves, and glands to and from the intestine are all called 
 mesenteric. They are all embedded in a variable amount of mesenteric fat. 
 Sometimes this fat is so abundant as to completely hide the vessels from view ; at 
 other times the vessels may be seen. 
 
 2 5 . Explain tlic primitive alimentary canal. 
 
 In figure 172 you have a view of the primitive canal and its mesentery 
 in longitudinal section. Will you remember that the mesentery has two layers 
 
 fade. U< 
 gast.Jiefiat: omcnt 
 
 I/MES. 
 
 FIG. 172. DIAGRAM OF THE PRIMITIVE ALIMENTARY CANAL. 
 
 with the arteries, that make the canal grow, between them ? You see in the figure 
 only one surface of the mesentery. At an early period there is only one gut and 
 one mesentery. This gut is straight, and located in the mid-line and on the pos- 
 terior abdominal wall. The gut grows in proportion to the blood-supply it receives. 
 In figure 172 this primitive mesentery had three important organs between its 
 two layers: (i) The stomach, in the middle; (2) the liver, between the two 
 layers, in front of the stomach ; (3) the spleen, between the two layers, behind the 
 stomach. 
 
 We see parts of this primitive partition unoccupied (i) in front of the liver; 
 (2) between the liver and stomach ; (3) between the stomach and spleen ; (4) 
 between the spleen and posterior wall. 
 
 26. Can ive find evidence in our dissection of the unoccupied parts just referred to ? 
 Yes ; the one in front of the liver is the broad or falciform ligament of the 
 
 liver. The one between the liver and stomach is the gastro- hepatic or lesser 
 omentum. The one between the stomach and spleen is the gastro-splcnic omentum. 
 
 27. Give the difference between omentum and mesentery. 
 
244 
 
 PR A CT1CAL A XA TO. MY. 
 
 In reality there is no difference except an arbitrary one. Each is of peri- 
 toneal origin ; each has two layers ; each escorts vessels and nerves to organs. 
 Omenta connect organ to organ ; mesenteries connect organ to wall. 
 
 28. Usage arbitrary. 
 
 The broad ligament holds the liver to the diaphragm ; the broad ligament ot 
 the uterus holds the uterus to the lateral pelvic walls and floor. They are the 
 mesenteries of these viscera. Usage, however, restricts the use of the word mesen- 
 tery exclusively to the intestines. As you will see, the ascending colon lost its 
 mesentery. The descending colon lost its mesentery, except the rectum, in part, 
 and the sigmoid. The transverse colon retained its mesentery. 
 
 29. Define mesentcric attachment primitive and acquired. 
 
 By primitive attachment of the mesentery we mean attachment in the mid- 
 line, or nearly in the original line of the straight gut. The mesentery of the small 
 intestine is, for practical purposes, art example of primitive attachment ; the rectum 
 is primitive in attachment. The duodenum, stomach, and colon have acquired 
 attachments. 
 
 aastro-liejiat. oment. 
 
 FIG. 173. DIAGRAMS SHOWING (A) THE FORMATION OF THE GREAT OMENTUM, AND () THE 
 
 TION OF THE INTESTINAL CANAL. 
 
 - 
 
 30. 
 cance ? 
 
 What is differentiation of the alimentary canal and its physiological signifi- 
 
 In the evolution of the alimentary canal, differentiation is the process whereby 
 the primitive straight gut undergoes a change which determines large and small 
 intestines. The ileo-caecal junction is the place where this change took place. 
 (Fig. 172.) The physiological significance seems to be simply a physiological 
 division of labor, whereby the small intestine is specialized for digestive purpose -s, 
 the large intestine for disinfecting, deodorizing, storage, and extrusive purposes. 
 
 3 1 . Wliat is rotation .' 
 
 It is the process by which the upper border of the small intestine (Fig. 173) 
 is turned from you, from left to right, and brought out toward you under the 
 arch of the transverse colon (Fig. 173), so as to be, when completely turned, as 
 tr.Mire 173. In figure 172 both large and small intestines have a common con- 
 tinuous mesentery, as you see. In figure 173 they still have the same mesen- 
 tery, with this difference : that for the small intestine is twisted on itself one-half 
 around. The pivot about which this rotation took place is seen in figure 172 
 the superior mesenteric artery. Kxaminc figure 172 and sec the jejunum. Trace 
 this down to the caecum. 
 
ABDOMEN. 245 
 
 This is an explanation of the fact you can demonstrate on the cadaver : that 
 the small intestine is almost completely surrounded by the ascending transverse 
 and descending parts of the colon. Show this on your work. 
 
 32. Formation of greater and lesser peritoneal cavities. 
 
 In figure 172 you have the primitive peritoneal partition dividing the abdom- 
 inal cavity into a right and a left half. In front of the stomach you see the gastro- 
 hepatic omentum ; behind the stomach the mesentery, which now takes the 
 specific name meso-gaster. You see the initial end of the small intestine (duo- 
 denum), and below this the remainder of the small intestine and all the large intes- 
 tine, attached by a common mesentery ; that peritonium, however, which corres- 
 ponds to the colon is called meso-colon, and that which corresponds to the small 
 intestine is called mesentery. Can you now distinguish the three meso-structures ? 
 Can you remember that each has two layers, between which are located the mesen- 
 teric arteries and other contents ? Can you remember that the attached margin 
 of this meso-gut now extends from the floor of the pelvis to the diaphragm, in 
 the mid-line ? Can you remember that the intestinal margin of the meso-gut 
 must become longer, in proportion to the growth of the intestine, large and 
 small ? Now you are on the left of this partition. Thus far the space on the right 
 is as great as that on the left. The arrow in figure 173 is represented as simply 
 coming through an artificial opening, to aid you in remembering the space on the 
 other side of the partition. Now imagine you took hold of the partition, the 
 meso-gaster, and pulled toward you in the direction of the dotted line. Would 
 you not, by continued pulling, produce a bagging-out on your side of the parti- 
 tion, and a consequent depression or bagging-in on the other side ? Can you 
 imagine, now, if you pulled long enough, the beginning of the depression or sac 
 on the other side must become smaller and smaller? The hole on the other side 
 would admit you to this little sac thus formed by your pulling. In anatomy the 
 name of this hole is the foramen of Winslow. It 'leads to the sac you have just 
 formed. This sac is the lesser cavity of the peritoneum ; all the space outside 
 of this is the greater cavity of the peritoneum. 
 
 33. What parts of the abdominal viscera, in the adult, have lost their peritoneal 
 covering by pressure atrophy, as referred to in a preceding paragrapJi / 
 
 No two cases are exactly alike in this regard. Still, the following represents 
 a general average, as you will meet these cases in the dissecting-room : (i) The 
 posterior part of the descending colon rests on the posterior wall of the abdomen, 
 consequently there is adhesion, with loss of the specific epithelial element. (2) The 
 ascending colon, the second and third parts of the duodenum, the colic and 
 duodenal elbows to be presently explained, rest on the peritoneum, partially in- 
 vesting the right kidney, and here is peritoneal loss. The second part of the 
 rectum is adherent to the anterior surface of the sacrum, and here is peritoneal 
 loss. Each case is a law unto itself, in a measure ; but the student with an ink- 
 ling of the developmental principles, as given in the foregoing, and as elaborated 
 in Morris, can soon acquire a facility in locating on his dissections, those peri- 
 toneal ruins, whose presence forms one of the mainstays for the receptacular part 
 of the alimentary canal, whose absence belongs to the rarest of rare developmental 
 freaks. 
 
 34. Does rotation occur in every case ? 
 
 Faulty rotation, and even failure to rotate, may occur. One interesting case, 
 found recently by the author, showed the caecum and the entire colon on the left 
 side, the small intestine in or near the right iliac fossa. 
 
 35. Are any special organs developed from the alimentary canal .' 
 
 The liver and pancreas are developed from the duodenum ; the former grows 
 into the mesentery in front of the stomach, the latter into the posterior meso-gaster. 
 You will see their ducts open in common into the second part of the duodenum. 
 
246 PRACTICAL ANATOMY. 
 
 SHORT SUMMARY OF PERITONEAL CONSIDERATIONS. 
 
 1. The complex adult alimentary canal and its complex peritoneal invest- 
 ing membrane are evolved from a simple straight gut and a simple straight mes- 
 entery. 
 
 2. The abdominal part of this canal in the foetus extends from the diaphragm 
 to the anus on the posterior wall of the abdominal cavity in front of the vertebral 
 column. It is attached to the anterior wall, as far downward as the umbilicus, 
 under the name of ventral mesentery. 
 
 3. The stomach appears as an enlargement in the canal, and its dorsal mesen- 
 tery is called meso-gaster. 
 
 4. The upper part grows much more rapidly than the lower, receiving a more 
 liberal blood-supply. In round numbers, the small intestine is the product of the 
 superior mesenteric artery ; the large intestine is the product of the inferior. 
 
 5. At an early period the liver is in front of the stomach and the pancreas 
 behind. The liver grows into the ventral mesentery, the pancreas into the pos- 
 terior meso-gastrium. The primary mesentery of the pancreas fuses with the 
 posterior body wall. 
 
 6. As the liver and spleen become larger, and as the bowel begins to rotate 
 about the superior mesenteric artery, the stomach assumes a transverse position, 
 the anterior border becomes the lesser curve, posterior border becomes the 
 greater curve, the left surface becomes the anterior, and the right surface becomes 
 the posterior. 
 
 7. The small intestine rotates from left to right in such a way that the large 
 intestine extends from right to left and crosses the small intestine near the 
 stomach. 
 
 8. Rotation accounts for the duodenum passing under the second or trans- 
 verse stage of the colon and apparently through its transverse meso-colon. 
 
 9. The meso-gaster becomes the greater omentum, consists of four layers, 
 grows out from the greater curvature of the stomach. 
 
 10. The duodenum and ascending and descending colon lose their mesen- 
 teries. 
 
 ABDOMINAL CONTENTS. 
 
 Cut slightly to the left of the umbilicus, then through the linea alba to the 
 ensiform cartilage. It may be necessary to divide the cartilages of the two or 
 three lower true ribs to make ample room. Make the following observations 
 before any further dissecting is done : 
 
 1. Find the broad ligament of the liver in the longitudinal fissure of this 
 organ. See the round ligament of the liver in the free margin of the broad. 
 This is the remains of the umbilical vein that brought aerated blood from the 
 placenta during intrauterine life. 
 
 2. Locate the stomach, I her, spleen, and transverse colon. Lift the lower 
 margin of the liver upward, and at the same time pull the stomach downward ; 
 now see the peritoneal connection between the liver and stomach the gastro- 
 hcpatic omentum or lesser amentum. Notice the peritoneal connection between 
 the stomach and the colon. This is the Castro-colic omentum or great omentum. 
 See the peritoneal connection between the left end of the stomach and the spleen. 
 This is the Castro-splenic omentum. Folds of peritoneum that connect organ to 
 
 are called omenta, and the three above given are the omcnta. 
 
Abdominal aorta 
 
 LEFT CRUS OF DIAPHRAGM 
 
 ISOPHAGEAL BRANCH 
 
 RIGHT CRUS Of DIAPHRAGM 
 
 Cystic artery 
 
 Sight phrenic artery 
 
 HEPATIC DUCT 
 
 CYSTIC DUCT 
 
 Splenic artery 
 
 COMMON BILE DUCT 
 
 Pyloric artery 
 
 Gastro-duodenal artery 
 
 Superior pancreatico- 
 duodenal artery 
 HEAD OF PANCREAS 
 
 Inferior pancreatico- 
 duodenal artery 
 
 Right gastro-epiploic 
 artery 
 
 Left gastro-epiploic artery 
 
 FIG. 174. THE CCELIAC ARTERY AND ITS BRANCHES. 
 
 BLADDER 
 
 GREAT OMENTUM 
 
 SMALL INTESTINE 
 
 FIG. 175. THE VISCERA AS SEEN ON FULLY OPENING THE AIJDOMEN WITHOUT DISARRANGEMENT 
 
 OF THE INTERNAL PARTS. (After Sarazin.) 
 
 247 
 
248 PRACTICAL ANATOMY. 
 
 3. Three Divisions of tlie Colon. The divisions of the colon are ascending, 
 transverse, descending, sigmoid, and rectum. The ascending colon extends from 
 the right iliac fossa to the hepatic flexure. The transverse colon extends from 
 the hepatic flexure to the lower margin of the spleen the splenic flexure. The 
 descending colon extends from the splenic flexure to the brim of the pelvis. 
 
 Notice the manner in which the three parts of the colon are held in place. 
 The meso-colon of the transverse is quite long ; that of the ascending and 
 descending is very short; in fact, the nature of the union is one of adhesion 
 rather than mesenteric, in the two latter. Folds of peritoneum that bind organs 
 to walls are called mesenteries. The continuation of the descending colon below 
 the pelvic brim, to a point opposite the second piece of the sacrum, is called the 
 sigmoid. Lift it up and see the great length of its mesentery called meso- 
 sigmoid. 
 
 4. Differential Diagnosis Between Large ami Small Intestine. Inflate the 
 large intestine (Fig. 175) and see the following differential points possessed by 
 large intestine but not possessed by small intestine : (i) Fatty masses. (2) Longi- 
 tudinal muscular bands, three in number, and at equal distances from each other. 
 Each will lead to the appendix. (3) Sacculations, produced by contraction exerted 
 by the longitudinal bands. 
 
 5- Jejunum, Ileum, and their Mesentery. Compare your dissection with fig- 
 ure 175 and you will observe that the three parts of the colon almost surround 
 the large central mass of small intestine. Collect this mass in your hands and 
 find the upper end of the jejunum going through the transverse meso-colon oppo- 
 site the third and fourth lumbar vertebra to become duodenum ; the lower end 
 you will find near the right iliac fossa, ending in the caecum, forming therewith a 
 junction called the ileo-caecal junction. Lift the whole mass of small intestine 
 upward, to estimate the length of the mesentery. 
 
 6. The Duodenum. Turn the transverse colon and great omentum upward. 
 Find the beginning of the jejunum and shut the same off the intestine below 
 this point by a ligature. Now inflate the alimentary canal above this point /. i\, 
 duodenum and stomach. You will now see the transverse part of the duodenum 
 passing behind the superior mesenteric artery and vein. 
 
 7. Ciecum and Appendix. You will find the caecum, as a rule, in the righ 
 iliac fossa. Its meso-caecum may be long in one case and short in another. 
 The longitudinal bands traced downward will lead to the appendix. This organ 
 has a peritoneal ligament the meso-appendix. It may occupy a variety of 
 locations. It may hang down in the pelvis across the brim. Its usual posi 
 tion is in an angle between the ileum and the pelvic side of the caecum. 
 
 A general review will now be made of what you have examined /// situ an 
 studied in the normal position without cutting. 
 
 1. You saw, on opening the abdomen, the walls and also the viscera (organs), 
 covered by a very thin, smooth, and glistening membrane peritoneum. The 
 layer covering the walls above, below, in front, behind, and on the sides is 
 called parietal peritoneum ; that covering the organs themselves is called 
 visceral peritoneum. The space between these t\\<> layers is the peritoneal cavity, 
 which contains only a small amount of serum f<>r lubrication. Henceforth you 
 will define a peritoneal cavity as a space between a visivr.il and a parietal laye 
 of peritoneum. (Fig. 171.) 
 
 2. On the interior of the abdominal walls you saw, through the thin parirta 
 
 ; 
 
ABDOMEN. 
 
 249 
 
 peritoneum, the urachus in the mid-line extending from the summit of bladder to 
 the umbilicus. This is the foetal remains of the stalk of theallantois ; it is covered 
 by peritoneum, and the particular name given the ridge or fold in this peritoneum 
 is plica urachi. This opening sometimes fails to close. 
 
 3. You saw on each side of the plica urachi the foetal remains of the hypo- 
 gastric arteries ; these are covered by peritoneum, called plica hypogastrica. 
 The triangular depression between these two plicae just noticed is the internal 
 inguinal fossa, and is associated with direct inguinal hernia. 
 
 4. You located the deep epigastric artery and veins. To the inner side of this 
 
 THYROID 
 
 LUNG 
 
 LIVER 
 Suspensory ligament 
 
 SMALL INTESTINE 
 
 BLADDER 
 
 LUNG 
 
 RIGHT AURICLE 
 
 RIGHT VENTRICLE 
 
 STOMACH 
 
 PART OF TRANSVERSE 
 COLON 
 
 Hypogastric artery 
 
 FIG. 176. THE VISCERA OF THE FCETUS. (Rudinger.) 
 
 artery you saw the middle inguinal fossa, associated with direct inguinal hernia ; 
 to the outer side the external inguinal fossa, associated (i) with the beginning of 
 the spermatic cord ; (2) with indirect or oblique inguinal hernia. You saw also 
 that this deep, epigastric artery forms the outer boundary of Hesselbach's tri- 
 angle. 
 
 5. You saw the femoral sheath, containing the femoral artery, vein, and femoral 
 canal. These structures you saw leaving the pelvis below Poupart's ligament. 
 The peritoneal depression corresponding to the beginning of the femoral canal 
 the femoral ring is the femoral fossa, and is associated with femoral hernia. 
 17 
 
250 PRACTICAL ANATOMY. 
 
 6. Tlie round ligament of t/ie liver, you will remember, extends from the 
 umbilicus to the liver. It is in the free border of the broad ligament of the liver. 
 It is the foetal remains of the umbilical vein. (Fig. 176.) You will remember 
 that in the child before birth, the placenta purifies the blood, as do the lungs, 
 after birth. The blood is* taken in an impure state to the placenta by the hypogas- 
 tric arteries, and returned pure by the umbilical vein. (Fig. 155.) 
 
 7. Three onienta are the gastro-hepatic, or small ; the gastro-colic, or great ; 
 the gastro-splenic. You learned to define omentum as peritoneal folds connect- 
 ing organ to organ. In your dissection you saw the great omentum as a heavy, 
 fatty veil, covering in all the small intestine, and hanging down even into the true 
 pelvis. This may even become a hernia, an omentoccle, and appear at any one 
 of the four fossae described in the foregoing review. 
 
 8. The Colon and Its Subdivisions (Fig. 175). The point where differentiation 
 takes place is usually in the right iliac fossa ; still, it may occur above this point. 
 You will see on your work two flexures in the colon the hepatic, at the lower 
 margin of the right lobe of the liver ; the splenic, at the lower margin of the 
 spleen. The transverse colon lies between these two flexures. The descending 
 colon is below the splenic ; the ascending, below the hepatic flexure. 
 
 9. You will examine and recall the nature of the colic attachments. That of 
 the ascending, and also of the descending, is in the nature of one structure 
 adherent to another ; their meso-colons, in other words, are short ; hence you 
 are not able to move them freely from place to place, as you can move the 
 transverse colon. On the other hand, the meso-colon of the transverse colon is 
 very long, due to which fact the transverse is the most movable part of the 
 colon. Also recall the definition for mesentery : peritoneal folds binding organ 
 to wall. The meso-sigmoid is also long. 
 
 10. Diagnostic of large intestine, you will remember, are the three longitudinal 
 muscular bands of fibres ; the consequent sacculations produced by these ; the 
 fatty masses called appendices epiploicce. The latter are variable in size ; in one 
 case they may be very large, in another quite small ; they are always present 
 on large intestine. Any one of the three bands will lead to the appendix. 
 
 1 1. As you will remember, you inflated the duodenum and studied the third 
 part of this organ as it passed behind the superior mesenteric vessels. The 
 remaining part of the small intestine is arbitrarily divided into an upper two-fifths, 
 called jejunum, and a lower three-fifths, called ileum. Jejunum means empty or 
 hungry, and ileum means coiled. There is no practical histological difference 
 between the two. They are held by their mesentery to a line extending from the 
 left side of the body of the second lumbar vertebra, to the right sacro-iliac 
 synchondrosis. In its course it lies upon, as you will presently see, the aorta, 
 vena cava inferior, transverse part of the duodenum, and vertebral column. Yoi 
 will see, then, that the mesentery of the small intestine forms a partition betuvrn 
 the right iliac fossa and the true pelvis; that fluid to the left of this partitioi 
 would be directed into the pelvis, to the right of the same, into the right iliac 
 fossa. Make this experiment. 
 
 You will now, by dissection, analyze the following localities and structim s 
 
 1. The foramen of Winslow. 
 
 2. The root-structures of the livrr. 
 
 3. The K-ssiT cavity of the peritoneum. 
 
 4. The inv.ikT cavity of tin- pi-ntoiu-um. 
 
 5. The ascriiding, descending, and transverse duodenum. 
 
ABDOMEN. 251 
 
 6. The pancreas and splenic artery. 
 
 7. The stomach and gastric artery. 
 
 8. The liver, hepatic artery, and portal vein. 
 
 9. The superior and inferior mesenteric arteries and veins. 
 
 10. The anterior relations of the right kidney. 
 
 1 1. The anterior relations of the left kidney. 
 
 1 2. The root structures of the kidney. 
 
 13. Descriptive renal terms. 
 
 The foramen of Winslow is the communicating passage between the greater 
 and lesser peritoneal cavities. The foramen has definite boundaries, which must 
 be located by each student, and then learned. Surgical operations on the gall 
 ducts of late years have made it imperative for the student of anatomy to have 
 such a thorough knowledge of structures in this locality, that by the sense of 
 touch alone, he may know perfectly both his longitude and latitude. The 
 foramen is variable in shape ; it may be round, semilunar, or triangular. As a 
 rule, it will admit two fingers. Introduce your left index finger and find, in front 
 of your finger, the front boundary the free border of the lesser omentum 
 containing the hepatic root -structures ; behind, the posterior boundary the 
 ascending vena cava and a ligamentous band of peritoneum extending from the 
 
 BALL BLADDER 
 
 Hepatic artery 
 
 Portal vein 
 
 FIG. 177. RELATION OF STRUCTURKS AT AND BELOW THE TRANSVERSE FISSURE. (Thane.) 
 
 liver to the right kidney ; above your finger, the caudate lobe of the liver; and 
 below, you will recognize the hepatic artery and the duodenum. 
 
 The Root-structures of the Liver (Fig. 174). Insert your finger into the 
 foramen of Winslow, and with your forceps plow through the anterior layer of 
 the gastro-hepatic omentum. You will now find three large structures, which a 
 few moves of the forceps will liberate from their bed of connective tissue : (i) To 
 the right side and below, and corresponding to the gall-bladder, the common bile 
 duct ; (2) to the left side and above, the hepatic artery ; (3) between these two, 
 but on a deeper plane, the portal vein. (Fig. 177.) Carefully examine the artery 
 and you will find numerous nerves surrounding the same. They come from the 
 pneumogastric and sympathetic. The connective tissue embedding these struc- 
 tures and escorting them to the interior of the liver is the capsule of Glisson. 
 
 The Bile Ducts (Fig. 174). These are three in number. The hepatic brings 
 bile from the liver ; the cystic is the duct between the gall-bladder and the point 
 where the hepatic meets it. The common duct begins at this point, passes 
 behind the first part of the duodenum, and under the head of- the pancreas, to 
 reach the retiring duodenal elbow, where, with the pancreatic duct, you will 
 find it opening into the duodenum. This duct is about four inches long. 
 
 The Hepatic Artery (Fig. 174). Trace this vessel to the cceliac axis. It 
 lies, as you will see, between the two layers of the lesser omentum. Follow its 
 
252 PRACTICAL ANATOMY. 
 
 cystic artery to the gall-bladder ; its pyloric branch to meet the gastric ; its 
 superior pancreatico-duodenal branch downward behind the duodenum ; here one 
 branch follows the second part of the duodenum and anastomoses with the 
 inferior pancreatico-duodenal branch of the superior mesenteric artery ; the other 
 follows the greater curvature of the stomach and, under the name of right gastro- 
 epiploica, anastomoses with the left gastro-epiploica, a branch of the splenic 
 artery. Finally, trace the main branch of the hepatic artery to the transverse 
 fissure of the liver. 
 
 The portal vein lies between the common duct and the hepatic artery. (Fig. 
 177.) It is formed by veins from the abdominal organs of digestion. Its blood is 
 laden with bile, glycogen, and urea. The bile is stored up in the gall-bladder ; 
 the glycogen is stored up in the liver; the urea is thrown off. Find the hepatic 
 veins discharging into the ascending vena cava, as this vessel passes through the 
 diaphragm. 
 
 The hepatic veins take all blood from the liver brought to that organ by 
 the hepatic artery and portal vein. The vein discharges into the ascending vena 
 cava, just as that vessel is passing through the diaphragm. 
 
 The Greater and Lesser Peritoneal Cavities. A knowledge of these cavi- 
 ties must be gained by study of the evolution of the peritoneum and alimentary 
 canal, from a straight gut and single simple mesentery. (See Morris.) The 
 foramen of Winslow connects all the cavity you can see thus far, with the lesser 
 cavity, behind the stomach. By mechanical devices your teacher will demon- 
 strate the modus operandi of rotation, and this demonstration will interpret the 
 description given in the larger text. Permit me to add in this place that every 
 organ, with all its adnexa, grows up behind peritoneum, pushes this ahead of 
 itself, and thereby becomes invested by the same, partially or completely.' 
 
 To Dissect the Duodenum. Thoroughly inflate the stomach and duodenum, 
 as previously directed. Then divide the gastro-colic omentum and turn the 
 transverse colon down toward the pelvis. Lift the stomach up, and observe the 
 lesser cavity of the peritoneum behind the same. In cutting the great omentum, 
 care must be taken not to injure the arteries along the greater curve of the 
 stomach. (Fig. 174.) Now remove the colon from the second stage of the duo- 
 denum. The stages of the duodenum are : (i) From the pylorus of the stomach 
 to the gall-bladder, two inches ; (2) from the gall-bladder to the hilum of the 
 kidney, three inches; (3) from the hilum of the kidney to the duodeno-jejunal 
 angle, five inches. These stages are called ascending, descending, and tram 
 verse, respectively. 
 
 Relations of Transverse Duodenum. You will find, above, the superk 
 mesenteric vessels and*the head of the pancreas; in front, the superior mesei 
 teric vessels, the mesentery, and small intestine. Behind you will now dissec 
 down with the forceps, and find the aorta, vena cava inferior, the crura of the 
 diaphragm, and the fourth lumbar vertebra. On the left, the transverse duode- 
 num terminates in the jejunum ; on the right, in the descending duodenum, 
 the middle one-third of the kidney. 
 
 The Pancreas and Splenic Artery. A very careful dissection of the pan- 
 creas must be made. The organ is delicate. It lies behind the stomach (Fig. 180) 
 hence turn the stomach up to expose the same. Steps : (i) Locate the splenic 
 artery by gently lifting the upper border of the pancreas. Follow the artery to 
 the spleen. You will now find it necessary to divide the Castro-splenic omentum, 
 but in cloin;4 this do not injure the arteries ! Notice and save the pancreatic 
 arteries, large and small, given to this organ the pancreas by the splenic artery. 
 Trace out the branches given to the stomach. Find the gastro-epiploica sinistra 
 artery. (2) Now dissect out the head of the pancreas. Trace the superior pan- 
 creatico-duodenal artery between the pancreas and the duodenum, taking notk 
 
 
ABDOMEN. 253 
 
 of branches to each. Find the excretory duct of this organ the pancreatic duct 
 opening into the duodenum with the common bile duct. 
 
 The Stomach (Fig. 174). This organ has an cesophagcal opening ; a 
 pyloric opening ; an anterior surface, on which you will find anastomosing the 
 transverse arteries from the gastric artery and the right and left gastro-epiploic 
 arteries ; a posterior surface, likewise occupied by arteries ; a greater curvature, 
 occupied by the greater omentum ; a lesser curvature, occupied by the lesser 
 omentum ; &fundus, in relation with the spleen by the gastro-splenic omentum. 
 Now trace the gastric artery from the coeliac axis to the gastro-oesophageal junc- 
 tion ; here you will see the artery divide into two branches one to the walls of the 
 oesophagus, the other to the cardiac end of the stomach. The main artery 
 follows the lesser curve of the stomach and anastomoses with the pyloric branch 
 of the hepatic artery. 
 
 The liver must be studied and dissected with reference to : 
 
 1. Lobes and their visceral impressions. 
 
 2. Fissures and their occupants. 
 
 3. Ligaments and their derivation. 
 
 4. Capsule of Glisson and its function. 
 
 5. Blood- and nerve-supply. 
 
 6. Fcetal remnants and their location. 
 
 7. The portal vein and its formation. 
 
 8. The hepatic veins and their escape. 
 
 9. The gall-bladder and bile ducts. 
 
 10. The descriptive terms used. 
 
 1 1. The relations to other structures. 
 
 Lobes. (i) Right lateral; (2) left lateral; (3) quadrate; (4) caudate; (5) 
 Spigelian. 
 
 Impressions are produced by continuous contact with certain adjacent organs. 
 On the under or visceral surface find: (i) the renal impression ; (2) the colic 
 impression ; (3) the duodenal impression ; (4) the gastric impression. 
 
 Fissures. (i) The transverse fissure is the most important. It transmits the 
 hepatic artery, the portal vein, the hepatic ducts, and the hepatic branches of the 
 vagus and sympathetic nerves. In front of it is the quadrate lobe ; behind it the 
 caudate and Spigelian lobes. (2) The left longitudinal. This separates the left 
 from the right lobes, and has an anterior and a posterior part. The anterior part 
 contains the round ligament ; the posterior part contains the remains of the ductus 
 venosus. (3) The fissure for the gall-bladder and (4) the fissure for the ascending 
 vena cava. Note, too, and show on your dissection, that on the posterior sur- 
 face of the liver are found two fissures already mentioned (a) fissure for the 
 ductus venosus, (b} fissure for the vena cava ; while on the inferior or visceral 
 surface are found three fissures (a) transverse, (b} umbilical for round liga- 
 ment, (c) vesicle for the gall-bladder. (5) The right longitudinal. This also 
 consists of an anterior branch that contains the gall-bladder and a posterior 
 branch that contains the vena cava. The two are interrupted by the caudate 
 lobe. Compare your dissection with figure 178. 
 
 The letter H includes the five fissures of the liver in this manner : the trans- 
 verse fissure forms the cross-bar ; the fissure for gall-bladder and fissure for vena 
 cava form one vertical bar ; the fissure for the ductus venosus and the fissure for 
 the round ligament form the other vertical bar. 
 
 The hepatic ligaments are five in number. One of these is a. false liga- 
 ment, a foetal remnant called the round ligament, the ligamentum teres hepatis. 
 It occupies the anterior part of the left longitudinal fissure. The other four liga- 
 ments are of peritoneal origin, and are called : (i) The suspensory, broad, or falci- 
 form ; (2) the right lateral ; (3) the left lateral ; (4) the coronary. The latter 
 
254 
 
 PRACTICAL ANATOMY. 
 
 binds, as you will see, the posterior surface of the liver to the diaphragm. The 
 lateral ligaments, which you will see on lifting the extremities of the liver, are 
 simply outward prolongations of the coronary ligament. The liver is firmly 
 fused with the diaphragm, a perfect appreciation of which you can only gain 
 from study of the embryology of the alimentary canal. 
 
 Vena cava 
 
 BILE DUCT 
 Portal ve; 
 ffe.patic artery 
 SPIGELIAN LOBE 
 
 UMBILICAL FISSURE 
 FIG. 178. THE INFERIOR SURFACE OF THE LIVKR. 
 
 LEFT LOBE 
 
 Vena cava 
 
 SPIGELIAN LOBE 
 
 FIG. 179. POSTERIOR SURFACE OF Tin I.ivi u. 
 
 Glisson's Capsule. You will recall your dissection of the root-structui 
 of the liver. Yon fouml the hepatic artery dividing into two branches, the portal 
 vein the same, and two hepatic ilncts coming down to join the cystic; you saw 
 nerves which are called hepatic branches from tin- vagus and sympathetic, sur 
 rounding the hepatic artery. Now recall this: the very intimate manner r 
 
 al 
 
 - 
 
ABDOMEN. 255 
 
 which these structures were bound together by connective tissue. This connec- 
 tive tissue is the capsule of Glisson the framework for the hepatic root-struc- 
 tures. 
 
 Hepatic Nerves and Arteries. The nerves reach the liver through the 
 transverse fissure, are protected in transit by the capsule of Glisson, are dis- 
 tributed to the substance of the liver on the branches of the portal vein and 
 hepatic artery. These nerves come from the hepatic plexus, one of the divi- 
 sions of the coeliac plexus. This plexus is made up of branches from the 
 sympathetic, the right phrenic, and the left pneumogastric or vagus nerve. The 
 nutrient artery to the liver is the hepatic. The liver receives blood for purifica- 
 tion from all the other abdominal organs of digestion, through the portal vein ; 
 all the blood in the liver escapes by the hepatic veins into the vena cava. To find 
 these veins, turn the liver clown into its normal position, locate the emergence of 
 the vena cava from the abdominal cavity through the diaphragm, and into the 
 pericardium. Now cut through the diaphragm at this point and plow through 
 liver substance, and you will find the hepatic veins. Another method is this : 
 having located the vena cava above the diaphragm, cut a hole in its walls and 
 follow the vessel downward until you see its hepatic tributaries. 
 
 Foetal Remains. These are the round ligament and the ductus venosus. 
 The former is the connective-tissue remnant of the umbilical vein, that in the 
 foetus brought pure blood from the placenta. (Fig. 155.) This vein, on reaching 
 the liver, broke up into three channels : (i) The greater part of the blood 
 joined the portal vein and traversed the liver ; (2) a small amount entered the 
 left lobe ; (3) a small quantity passed through a vessel the ductus venosus to 
 meet the left hepatic vein, as that vessel was entering the vena cava. After the 
 lungs became the organ of respiration, the placental circulation lost its specific 
 character as a conduit, t The main vessel, the umbilical vein, dwindled to a mere 
 cord the round ligament. The three termini of the vein did the same, and are 
 known as remnants. The ductus venosus dwindled, and is consequently in the 
 adult a fcetal remnant. 
 
 The portal vein in its relation to the root-structures of the liver will be seen 
 in figure 177. In your dissection you have found it embedded in Glisson's cap- 
 sule, and occupying a place between the hepatic artery and common bile duct, 
 and posterior to both. Its tributaries come from all the organs in the abdominal 
 cavity associated, with the digestion of food, except the liver. The veins which 
 you must demonstrate on your dissection as forming the portal vein are : (i) The 
 superior mesenteric ; (2) the inferior mesenteric ; (3) the splenic ; (4) the 
 gastric. Notice particularly on your dissection that three veins the gastric, 
 splenic, and superior mesenteric come together to form the portal vein directly ; 
 the inferior mesenteric is tributary to the splenic, hence it is not a primary, but a 
 secondary tributary to the portal vein. 
 
 The hepatic veins must be located according to the two methods given under 
 caption of Hepatic Nerves and Arteries. (Page 253.) Having found the hepatic 
 vein, look on its under surface for "the remains of the ductus venosus, for, you 
 will remember, one branch of the umbilical vein in the foetus terminated here. 
 
 (Fig. I55-) 
 
 The gall-bladder and its system of ducts must now be carefully dissected. 
 Any degree of rough manipulation will defeat a perfect dissection. Follow these 
 steps : (i) Take the organ in the left hand, and with your forceps in your right 
 carefully dissect the connective tissue, holding the gall-bladder in the cystic 
 fissure. (2) Having now liberated the organ from its bed, and having exercised 
 every care not to injure the vessels and ducts attached thereto, you may (3) cut 
 a slit in the fundus of the organ, introduce a blowpipe, and inflate. (4) Have an 
 assistant ligate as you inflate. (5) Now follow downward, and liberate from the 
 
256 PRACTICAL ANATOMY. 
 
 capsule of Glisson the ducts : hepatic (two), cystic, and common. Follow this 
 latter, the common bile duct, three and one-half inches to its confluence with the 
 pancreatic duct, in the receding angle of the duodenum. 
 The descriptive terms used in speaking of the liver are : 
 
 1. The root, transverse fissure, or porta hepatis. This is where the vessels, 
 nerves, and ducts enter, surrounded by the capsule of Glisson. 
 
 2. T/ie superior or phrenic surface is in relation to the inferior surface of the 
 diaphragm. It is covered by peritoneum, except a small space between the two 
 layers of the suspensory ligament. 
 
 3. The inferior or visceral surface rests on the stomach, duodenum, colic 
 elbow, right kidney. Two places are not covered by peritoneum : the fissure in 
 which the gall-bladder rests and the transverse fissure. Surgically, this is the 
 most important part of the liver, and should be most faithfully studied by the 
 student. 
 
 4. The posterior surface is a territory you can see only when you remove the 
 liver. It is mostly uncovered by peritoneum, and is limited by the anterior and 
 posterior layers of the coronary ligament. 
 
 5. Tlie anterior border is the one interrogated in physical examinations of the 
 liver. It is quite thin and is marked by two notches, one for the suspensory liga- 
 ment and one for the fundus of the gall-bladder. This latter is, in health, oppo- 
 site the ninth costal cartilage. This border is about in line with the ribs. 
 
 6. The extremities, right and left, are associated with the lateral ligaments, but 
 have no special importance in physical diagnosis. The hepatic elbow a coinage* 
 will be explained when the anterior relations of the right kidney are considered. 
 
 7. Peritoneal investment of the liver is for practical purposes complete ; never- 
 theless, on each surface we have found areas not completely covered. This has 
 been explained under the head of peritoneum on page 238. 
 
 The relation of the liver to other organs is one of the most fascinating 
 and instructive parts of the work thus far encountered, (i) Now show on your 
 dissection that the superior surface of the liver is related to the under surface of 
 the diaphragm, and separated by the diaphragm from the bases of the lungs, base 
 of the pericardium, anterior abdominal wall, and six or seven lower ribs on the 
 right side. (2) Show that the inferior surface of the liver lies on the right kidney 
 and its adrenal ; on the hepatic flexure of the colon ; on the descending duode- 
 num ; on the gall-bladder and its duct ; on the root-structures of the liver; or 
 the right end of the stomach ; on the upper curve of the duodenum ; on th< 
 anterior surface and lesser curve of the stomach ; on the lesser omentum. 
 Show that posteriorly the liver is in relation with the diaphragm and its crui 
 the tenth and eleventh thoracic vertebrae and their ribs, the oesophagus, aorta, 
 vena cava, and thoracic duct. To show these posterior relations separate the 
 liver from the diaphragm and pull it far forward, but do not injure the vena cava 
 you may ligate and then cut the hepatic veins. This will give you an opportu- 
 nity to study the coronary ligament also. All the above relations are to be studied 
 without cutting anything except possibly the hepatic vein, as above indicated. 
 
 The Superior Mesenteric Artery. To make a good dissection of this 
 artery and its branches, turn the transverse colon up and pull the mass of small 
 intestine forming the jejunum and ileum far down over the left iliac region, as 
 shown in figure 180. Now, remember the mesentery contains, between its two 
 layers, all the vessels, glands, nerves, and lymphatics that go to or come from 
 the small intestine. Remember all those struetmvs arc embedded in connective 
 tissue, just as are the root-structures of the liver enclosed by Glisson's capsule 
 that the function of this mesenteric connective tissue is, like Glisson's capsult 
 protective and supportive-, and contains, in some persons, large quantities ot I. it 
 technically designated mesenteric fat. 
 
ABDOMEN. 
 
 257 
 
 Dissection. Locate the main stems of the artery and vein as they emerge 
 from the under border of the pancreas, gently thrust your forceps never the 
 scalpel through the upper layer of. the mesentery, then use your fingers instead 
 of the forceps and you can easily strip off the remainder of the peritoneum out 
 to the intestinal margin of the mesentery. Trace out with your forceps, by 
 removing the mesenteric connective tissue, always in the direction of the vessel, 
 the following branches: (i) The ileocolic branch to the appendix, caecum, 
 ascending colon, and ileum ; (2) the right colic artery to the ascending colon ; 
 (3) the middle colic artery to the transverse colon ; (4) the main bulk of the 
 artery to the jejunum and ileum under the name of intestinal branches or vasa 
 
 Left colic artery 
 
 Superior mesen- 
 teric artery and 
 vein 
 
 Ileo-colic artery 
 
 VERMIFORM 
 APPENDiX 
 
 Vasa intestini 
 tennis 
 
 SMALL INTESTINES 
 
 FIG. 180. THE SUPERIOR MKSENTERIC ARTERY AND VEIN. 
 (The colon is turned up, and the small intestines are drawn over to the left side.) 
 
 intestini tenuis ; (5) a small branch already found the inferior pancreatico- 
 duodenalis. The veins must be dissected at the same time. If now you will 
 thoroughly wash the mesenteric fat away with ether, and permit the specimen to 
 dry, the sympathetic nerves accompanying the arteries may be seen. 
 
 The Inferior Mesenteric Artery. To dissect this artery and its accompany- 
 ing vein, take the mass of jejunum and ileum far over to the right side. (Fig. 181.) 
 Locate the main stem of the artery at its origin from the abdominal aorta, 
 make a hole through the peritoneum, and, as in the dissection above described, 
 strip off the peritoneum. Now trace out the following branches : (i) The sig- 
 moid artery to the sigmoid flexure of the descending colon ; (2) the superior 
 
258 PRACTICAL ANATOMY. 
 
 haemorrhoidal artery to the rectum ; (3) the left colic artery to the descending 
 colon. 
 
 Summary. (i) The descending colon and rectum are supplied with blood 
 by the inferior mesenteric artery. The blood from this area is returned by the 
 inferior mesenteric vein, which passes behind the pancreas and is tributary to the 
 splenic vein. (2) The remaining part of the intestinal canal, below the stomach, 
 including the small intestine and the ascending and transverse colons, is supplied 
 by the superior mesenteric artery. The blood from this area is collected by veins 
 which come together to form, with the gastric and splenic veins, the portal vein. 
 The name portal circulation is given to the veins coming from all the abdominal 
 
 Middle colic artery 
 
 Inferior pancreattco- 
 
 duodenal artery 
 
 Superior mesenteric 
 
 artery 
 
 Riyht colic artery 
 
 A bdominal aorta - 
 Vena cava inferior . 
 
 Right common iliac _ 
 
 artery 
 
 Middle, sacral artery 
 and vein 
 
 I.fft colic artery 
 
 JuJ'erior inrsenleric 
 
 1 1 in 
 
 Inferior mrsni/i rir 
 artery 
 
 Left co/ic ttrlerii 
 !iij< rior in i. ie liter ic 
 artery 
 
 Left common iliac 
 
 i-i in 
 
 Sigmoid artery 
 
 Superior tiii'tiiur 
 r/tuiilal tirlt-ry 
 
 FIG. 181. THE INKKKIOK MISKN 1 1 UK- AKTKKY AND VKIN. 
 (The colon is turned up, and the small intestines are drawn to the right side.) 
 
 organs of digestion, except the liver. This blood is laden with urea, glycogen, 
 and bile, all of which are removed from the blood in the li\vr. 
 
 Anastomosis of Arteries to the Abdominal Organs of Digestion. (i) 
 
 Tin- gastric artery from the cceliac axis supplies the abdominal part of the (esoph- 
 agus, the side of the stomach represented by the lesser curve, and anastomoses 
 with the hepatic, at the pyloric end. (2) The hepatic artery supplies the liver 
 and communicates, through the Castro-duodenal artery, with both the splenic 
 and superior mesenteric arteries. (3) The several branches of the mesenteries 
 successively anastomose, so you can trace- from (esophagus to rectum the con- 
 tinuous blood-supply to all the viscera of this system. 
 
 Anterior Relations of the Right Kidney. The anterior surface of the 
 right kidney is occupied, from the kidney forward, (i) by the anterior part of the 
 fatty capsule ; (2) by the following organs : liver, duodenum, colon. For the 
 
ABDOMEN. 
 
 259 
 
 purpose of aiding the memory, call the visceral relation that of the three 
 elbows : the hepatic elbow, the duodenal elbow, the colic elbow. Now demon- 
 strate as follows : Carefully pull the hepatic flexure of the colon downward, and 
 notice that this is made up of the upper end of the ascending and the proximal 
 end of the transverse colon, and rests approximately on the lower third of the 
 kidney. (Fig. 182.) Next trace down the second part of the duodenum (inflated), 
 and see that it forms a flexure where it joins the transverse duodenum. Turn 
 this off and call it the duodenal elbow, observing that it occupies the middle third 
 of the kidney. Lastly, observe the anterior border of the liver come down and 
 suddenly recede backward and upward. It covers the upper third of the anterior 
 surface of the kidney, and forms the hepatic elbow. 
 
 Notice, too, that the areas occupied by the duodenal and colic elbows have 
 lost their peritoneum, in accordance with a law explained under the head of peri- 
 toneum. The left kidney has two non-peritoneal areas. 
 
 Anterior Relations of the Left Kidney. The first relation is the fatty cap- 
 sule. Then the following viscera you will remove in this order : (i) The fundus 
 
 DUODENAL AREA HEPATIC AREA GASTRIC AREA 
 
 (NON-PERITONEAL) (NON-PERITONEAL) CAVAL AREA (PERITONEAL) 
 
 DUODENAL AREA 
 (NON-PERITONEAL) A\ 
 
 PANCREATIC AREA 
 (NON-PERITONEAL) 
 
 COLIC AREA 
 (NON-PERITONEAL) 
 
 COLIC AREA OF 
 SPLEEN 
 
 COLIC AREA 
 (NON-PERITONEAL) 
 
 PERITONEAL AREA WITH RIGHT 
 COLIC VESSELS 
 
 PERITONEAL AREA WITH LEFT 
 COLIC VESSELS 
 
 FIG. 182. DIAGRAM SHOWING ANTERIOR RELATIONS OF KIDNEYS AND SUPRARENAL BODIES. 
 
 of the stomach ; (2) the tail of the pancreas ; (3) the descending colon ; (4) 
 the last part of the duodenum. 
 
 Posterior Relations of Each Kidney. Carefully remove the kidney from 
 its bed of fat and connective tissue, and turn the same to the mid-line with all 
 its root-structures attached. Great care must be taken in handling the left one 
 not to injure the left spermatic vein (ovarian, if a female), which discharges into 
 the left renal vein. Then, having removed the posterior part of the fatty capsule, 
 you will find three nerves: (i) The last thoracic; (2) the ilio-hypogastric ; (3) 
 the ilio-lumbar. Then you will be able to make out the (i) quadratus lumborum 
 muscle, covered by the anterior lamella of the lumbar fascia; (2) the diaphragm ; 
 (3) the psoas magnus muscle ; and (4) the lowest intercostal artery. 
 
 The Root-structures of the Kidney (Fig. 183). These are, from before back- 
 ward, as met in your dissection : (i) The vein ; (2) the renal artery and its sym- 
 pathetic nerves ; (3) the expansion of the ureter, known as the pelvis of the kid- 
 ney. You will find these structures loosely bound together by connective tissue, 
 like the capsule of Glisson or the mesenteric connective tissue. This you must 
 divide in the direction of the structures. You will now puncture the ureter in 
 
260 
 
 PRACTICAL ANATOMY. 
 
 the region of the brim of the pelvis and inflate the same to see the beauty of the 
 pelvis of the kidney. 
 
 Descriptive Terms. The kidney has a superior and an inferior extremity ; an 
 anterior and a posterior surface ; a strong fibrous capsule, which may be easily 
 peeled off. The place where the nerves, vessels, and duct pass into the kidney 
 is called the hilum. (Fig. 183.) Cut through the kidney longitudinally, from 
 the outer to the inner border, and see the cortical and pyramidal structure of the 
 
 Cystic artwy 
 
 HEPATIC DUCT 
 
 CYSTIC DUCT 
 
 COMMON DUCT 
 
 Putin/ a i ,. 
 
 Gastro-duodenal br. 
 
 Superior pylnrii- In 
 
 Hepatic arlrri 
 
 Right suprarenal mY 
 Inferior tvpi-inrim' 
 artery 
 Renal artery 
 
 Renal vein 
 
 Inferior vena cava 
 KIDNEY 
 
 Right spermatic vei 
 
 Right spermatic artery 
 
 Quadratus lumborum 
 
 muscle 
 
 Right lumbar artery and 
 left lumbar vein 
 Ureteric branch of 
 spermatic artery 
 
 Middle sacral vessels 
 
 LEFT LOBE OF LIVER 
 
 (ESOPHAGUS 
 
 Left phrenic artery 
 
 Right phrenic artery 
 Superior suprarenal 
 Gastric artery 
 Inferior suprarenal 
 Splenic artery 
 
 Left phrenic rein 
 Left tuprarena: 
 Superior meseiiteric 
 
 artery 
 KIDNEY 
 
 Ureteric branch of renal 
 Left spermatic rein 
 
 URETER 
 
 Left spermatic artery 
 
 Inferior mesenteric artery 
 
 Ureteric branch of 
 spermatic 
 
 Ureteric branch of 
 
 common iliac 
 Common iliac artery 
 
 External iliac arle 
 Internal iliac artery 
 
 FIG. 183. THE ABDOMINAL AORTA AND ITS BRANCHKS, WITH TIIK INFERIOR VENA CAVA AND ITS 
 
 TRIBUTARIES. 
 
 kidney. Figure 613 (Morris) shows the interior of the sinus and the formation of 
 the pelvic portion of the ureter. The ureter having been inflated, examine for 
 one or more small urcteric arteries, branches of tin spennatic, superior vesical, 
 and common iliac arteries on the ureter. Connected with the upper extremity 
 of the kidney by connective tissue, find the adrenals or suprarenal capsules. These 
 arc ductless glands. Trace out their arteries to the renal and phrenic arteries 
 and to the aorta. 
 
ABDOMEN. 261 
 
 THE SYMPATHETIC NERVE. 
 
 In the cranium, neck, thorax, abdomen, and pelvis you will have to do with 
 arteries, nerves, viscera, and localities where the sympathetic nerve, while perhaps 
 anatomically the smallest structure, in these localities is nevertheless the most 
 important structure. It would be just as wanton to ignore and destroy, or, 
 what is worse, fail to see, the hairspring of a watch, if you were taking a watch 
 to pieces, as it would be to dissect a human body and not have a clear under- 
 standing of the sympathetic nerve. 
 
 The necessity of at least familiarity with the rudiments of this system of 
 nerves will be apparent, when I remind you that you will hear more or less 
 about the sympathetic nerve from every chair in your medical course. The 
 physiological action of drugs depends on vaso-contraction and dilatation to a 
 great extent. The rationale of the obstetrician's Crede manipulation, is stimula- 
 tion of sympathetic uterine contraction. The physiologist invokes the sympa- 
 thetic system when he would explain the function of viscera. The pallors and 
 hyperaemias, the exanthemata, and the thousand and one strange phenomena in 
 skin diseases are, to a greater or less degree, temporarily or permanently amen- 
 able to remedies that act in some way through the sympathetic. In general 
 and special medicine, in surgery and all its special departments, you will hear of 
 parts played by the sympathetic nerve. Are you, then, to remain in ignorance, or 
 are you to gain a comprehensive knowledge of this subject by intelligent dissection ? 
 
 An erroneous opinion prevails among students that the sympathetic cannot 
 be seen, on account of its smallness. No ; this is not the reason students often fail 
 to find and become familiar with these nerves. You can see at a distance of six 
 feet the cervical, thoracic, and abdominal ganglia, of the gangliated cord. You 
 can see at a distance of ten feet the solar and cardiac plexuses. You can see at a 
 distance of four feet the hypogastric plexus. You can see at a distance of two 
 feet the communicating branches extending from one ganglion to another of the 
 gangliated cord. You can see the greater and lesser splanchnics five feet away. 
 At a distance of fourteen inches you can see the rami communicantes the little 
 nerves connecting the sympathetic cord and the anterior primary divisions of the 
 spinal nerves. At a distance of twelve inches you can see the gastric, hepatic, 
 splenic, and mesenteric sympathetic nerves. At a distance of ten inches you can 
 see the sympathetic nerves on the internal carotid artery in its cavernous, petrosal, 
 or cerebral stages. You can see the Vidian nerve, the petrosal nerves, the ophthal- 
 mic ganglion. At the closest normal visual range you can even see the sympa- 
 thetic nerves that accompany the ovarian and uterine arteries. You can even 
 see the long and short ciliary nerves to the eyeball. 
 
 I saw a man last summer who could not see the moon through a Yerkes 
 telescope. In this case the moon was on exhibition, and the powerful lens was 
 in working order, but the man in question did not know where to look. So, in 
 anatomy, the sympathetic nerve is everywhere on exhibition. Its dimensions 
 are not great, it is true ; still, if you know where to look, you will have no diffi- 
 culty in finding this nerve. The peculiar sympathetic lustre makes its identity 
 certain, after you have dissected and studied this nerve a short time. The object 
 of this chapter is to teach you where to look, to find the sympathetic nerve in 
 all regions of the body ; to teach you how to let the nerve alone, having once 
 found the same and this is its dissection ; to furnish you with an outline, 
 embracing the rudiments of what is known of the sympathetic to-day and this 
 by the following questions and their answers : 
 
 I . What is a sympatJietic nerve ? 
 
 Cranial and spinal nerves are collectively designated somatic nerves. These 
 
262 
 
 PRACTICAL ANATOMY. 
 
 preside over the special senses and supply muscles with motion and skin and 
 membranes with sensation. These muscles and parts, constituting so much of 
 the bulk of the body, depend on certain organs for air, blood, for the products 
 of digestion ; in other words, there are certain organs in the body concerned in 
 the preparation of nutriment for the tissues. This nutriment must be distributed 
 
 n of Sites 
 
 to G.ofRoot ofPneumog, 
 taPe-trosal G. 
 Glosso-ph. 
 
 Vidian to$-P Ganglion 
 
 to U.ofPne utnoycutrtc 
 tofffpoyloaaal Jff. 
 
 to br. of Ext. Carotid. A. 
 
 to Pharyngeal P 
 to Inf. Thyroid A . 
 
 Cardiac br.fkPneumogast. 
 andfiec.Laryrufeal Kcrvr 
 
 CarcLiac Plexus 
 .Coronary Plexus 
 
 G.= GANGLION. 
 P.= PLEXUS. 
 A.-ARTERY. 
 
 1. 2.3.*. BRAN CHES. 
 FROM PNEUMOGASTSiC 
 NERVE TO THE CARDIAC 
 PLEXUS. 
 
 kpaticP. , 
 ,^-f^f Cystic 
 
 Gaslrvjtuadenal 
 
 4th 
 from Couyyoal 
 
 Ganglion Impar. 
 FIG. 184. Tin SY> 
 
 5 Sup.ffemorrnoidaL 
 6 Spermatic Plexus. 
 
 Pelvic P. orlnfHypogastric. 
 
 SUPPLIES ALL THE PELVIC VISCERA AND THE PENIS. 
 
 Frvm fbttsrS Compend of Anatomy. 
 SYSTEM OF NERVES. 
 
 to the tissues, at tinu-s in maximal cuiantities, at other tinu-s in minimal cjuantitics. 
 Tin- action of the s\-mpathetic is, among other things, to dilate or contract the 
 vessels bearing this blood, for thr nutrition of the tissues. In this sense then 
 a feeder of organs, the sympathetic looks after the lixes of organs hence its 
 synonym, tlu- mrve of organic life. 
 
ABDOMEN. 263 
 
 2. From where to where docs the gangliated cord extend ? 
 
 From the ganglion of Ribes above, on the anterior communicating artery, to 
 the ganglion impar below, on the coccyx. 
 
 3. Hou> many ganglia are in each region of the spine / 
 
 Three in the cervical ; twelve in the dorsal ; four in the lumbar ; four in the 
 sacral region. 
 
 4. Where will we find these ganglia in the cervical region in dissection f 
 
 In the neck, behind the carotid sheath, the superior cervical ganglion ; on 
 the inferior thyroid artery, the middle cervical ganglion ; on the inner side of the 
 superior intercostal artery, the inferior cervical ganglion. This one is somewhat 
 difficult to find, as it lies in fatty connective tissue. Look between the trans- 
 verse process of the seventh cervical vertebra and the neck of the first rib, and 
 you will find it. Dissolve the fat in ether and pack the region with a two per 
 cent, solution of formaline, to develop well the branches of this ganglion, which 
 branches are somewhat numerous. 
 
 5 . Where are the ganglia located in the thorax ? 
 
 You will find them in fatty connective tissue, behind the pleura costalis, on 
 the heads of the rib. These are smaller than the cervical, but easily found. 
 
 6. Where will we find the ganglia in the lumbar portion of the gangliated cord ? 
 Along the inner margin of the psoas magnus muscle, behind the peritoneum, 
 
 in fatty connective tissue. 
 
 7. Where vvill we find the ganglia in the sacral region of t/te gangliated cord? 
 Along the inner side of the anterior sacral foramina, behind the peritoneum, 
 
 in fatty connective tissue. 
 
 8 . Hcr L v are these ganglia, in the regions above mentioned, connected ? 
 
 By interganglionic cords or nerves. These can all be seen, and must be 
 demonstrated on the cadaver by the student. 
 
 9. What are the rami commnnicantes ? 
 
 They are two little nerves that extend from the spinal nerve, shortly after its 
 emergence, to the ganglia of the gangliated cord. These are the somatic com- 
 munications referred to above. 
 
 i o. How do sympathetic nerves reach the organs or parts they are destined to 
 supply ? 
 
 In two general ways : (i) The majority of sympathetic nerves travel with 
 the artery to the organ, and take the same name as the artery. (2) Some few 
 accompany somatic nerves to a part ; the sympathetic nerves to the pharynx 
 accompany the vagus and glosso-pharyngeal nerves, and then take the name of 
 the part supplied. 
 
 1 1 . Are there any important nerves given off from the superior cervical gan- 
 glion ? If so, zv/iat arc they, and where are they distributed ? 
 
 Yes ; from the ganglion are given off branches that accompany the branches 
 of the internal carotid artery to the brain ; the ophthalmic artery to the orbit ; 
 communicating branches to the third, fourth, fifth, and sixth cranial nerves. 
 
 1 2. What branches are given off from the middle cervical ganglion ? 
 Nerves to all the branches of the external carotid artery ; nerves to the 
 
 pharyngeal plexus ; a nerve the superior cardiac nerve. 
 
 13. What nerves are given off from the inferior cervical ganglion f 
 From this are given off the principal nerves to the cardiac plexus. 
 
 14. Explain the sympathetic distribution from the twelve thoracic ganglia. 
 
 In round numbers, the six upper are given to the cardiac plexus ; the six 
 lower to the solar and renal plexuses, by the splanchnics. 
 i 5. How is the hypogastric plexus formed f 
 
 By branches from the lumbar and sacral parts of the gangliated cord. 
 1 6. What is the function of the cardiac prevertebral plexus ? 
 
264 
 
 PRACTICAL ANATOMY. 
 
 It supplies lungs and heart. It is formed by sympathetic nerves, supple- 
 mented by filaments of the phrenic and vagus nerves. 
 
 17. How is the solar plexus formed, and to what organs arc its brandies dis- 
 tributed.'' 
 
 1 5** Cranial tferve 
 2. The Orbit 
 
 3 3 rd 4^6^ Cranial tfe 
 
 4 To the Arteries of the ffraiti 
 
 to (LofRoot ofPneumog. 
 toPttrosal ff.of^ 
 Glos.so-ph. 
 
 7o muscles concerned 
 in respiration 
 Cervical Plexus 
 Somatic Pain 
 
 To upper extremity 
 Brachial Plexus 
 Somatic Pain 
 
 To Thoracic Walls 
 6 upper intercostals 
 
 Somatic Pain 
 
 To Abdominal Walls 
 6 lower intercostals 
 
 < ; 
 
 Somatic Pain 
 
 Lumhar Plexus 
 
 To front ofThioh anJ/fnet 
 
 \ 
 
 Somfi/ic Pain 
 
 Sacral Plexus 
 
 To posterior part ofThiah 
 
 To Lea 
 
 To external Genitals 
 
 Somatic Pain 
 
 G.'GANOLION. 
 
 Cardiac br. fhPn eu-mogastric p. = p L E x u s . 
 andRec.Larynytal Rcrves A.. ARTERY. 
 
 G.ofWrisberg 
 
 'Cardiac Plexus . n ^ ffgarf ana < Lun j S 
 
 1.2.3.4. BRAN CHES. 
 FROM PNEUMOOASTRIC 
 
 NERVE TO THE CARDIAC 
 PLEXUS. 
 
 r epaticR . 
 ; u^rf Cystic 
 
 Gastrculuadenal 
 
 the Abdominal Oryam 
 
 S Sup.Hemorrfioidal. 
 6 Spermatic Plexus. 
 
 > To the Pelvic 0/yans 
 
 Pelvicp.orlnfflypogaslnc. 
 
 SUPPLIES ALL THE PELVIC VISCERA AND THE PENIS. 
 
 from Couyyoal 
 
 Ganglion Impar. 
 
 Fivrn'tbtterS Compend ofJlnatomu. 
 FIG. 185. THE SYMPATHETIC SYSTEM OF NERVES. 
 
 By the sympathetic, as above indicated, in union with filaments from the 
 vagus nerves. It is distributed to the abdominal organs, exclusive of the organs 
 in the pelvis. 
 
 1 8. To what is tlie liypogastric /Vr.ivc.v distributed / 
 
 To the organs in the pelvis. It will be remembered the nerves reach organs 
 
ABDOMEN. 265 
 
 by accompanying the artery to the part. Hence it occurs that the ovary and 
 testicle receive their nerve-supply from the renal plexus. 
 
 In the subjoined figure the tendency of plexuses to supply areas below their 
 own level will be seen. 
 
 19. Wliat is meant by automatic action in sympathetic ganglia ? 
 
 The ganglia of the heart and intestine have the power of independent action ; 
 still, the sympathetic is no longer considered a separate system. 
 
 20. Is there any definite means of judging of the location of disease founded on 
 the nature or location of pain ? Or, conversely, may pain incident to disease of the 
 various organs in the three great cavities thorax, abdomen, and pelvis be ration- 
 ally accounted for in the distribution of cerebro-spinal or somatic nerves ? 
 
 Yes ; for, as the following pages will show, somatic nerves often report pain 
 that has its origin in an organ far away from the origin. These somatic nerves 
 also transmit both pain and motion more rapidly. 
 
 For an example, in valvular lesion the pain in the chest behind the sternum, 
 so long as reported by the sympathetic nerve to the patient as a subjective 
 symptom of disease, is constant and aching. When, however, the case assumes 
 a grave aspect, and the pain is reported to the patient's sensibility by the somatic 
 nerves, then an aching pain is replaced by one described as darting and stabbing. 
 Then, too, the location of the pain will have changed. The aching sympathetic 
 pain behind the sternum is now felt in the little and ring fingers. Consult the 
 characters of sympathetic and somatic pain in the following paragraphs. Con- 
 sult figure 185 and see : (i) The heart is supplied by sympathetic nerves by the 
 cardiac plexus ; (2) the sympathetic nerves forming the cardiac plexus com- 
 municate with the somatic nerves in the area where are given off the nerves 
 forming the brachial plexus ; (3) as sensory nerves report pain peripherally, 
 we may logically account for the digital pain in valvular lesions in the distri- 
 bution of the brachial plexus in general, or in the specific distribution of the 
 ulnar nerve in particular. The same is true of all diseases of viscera in which 
 pain figures conspicuously as a subjective symptom. To find the possible 
 somatic area where pain may occur, use figure 185 according to the following 
 steps : (a) Where is the diseased organ located ? (V) Are the organs in this 
 area supplied by the cardiac, solar, or hypogastric plexus ? (<r) At what place 
 do the sympathetic nerves forming the plexus, supplying the organ under 
 consideration, communicate with the somatic or spinal nerves? (4) What 
 becomes now of the spinal nerves given off where the sympathetic communicate 
 with them ? Do these spinals form either the cervical, brachial, lumbar, sacral, 
 or coccygeal plexus, or do they form the thoracic nerves? (5) Trace out the 
 distribution of the spinal nerve, and you will have the somatic route pursued by 
 pain originating in the sympathetic area. The steps then would be : \d] sympa- 
 thetic area ; ($) communicating branches with the somatic nerves ; (<:) transfer 
 centre in the cord, (d] Somatic distribution of nerves over which pain may travel. 
 Articulations may be involved in reflex pain. In the case of pain in the little 
 finger incident to valvular lesion, the student must be prepared to answer the 
 question, Where may the pain have been in this same valvular lesion, aside from 
 in the skin of the little finger and one-half the ring finger ? (6) The same nerve, 
 the ulnar, also sends sensory branches to every articulation, which any of the 
 muscles supplied by its motor filaments moved or assisted in moving ; hence in 
 the elbow or any of the following joints a reflex pain, darting and stabbing in 
 character, may be a sequel of valvular heart lesions. (7) Distribution of cranial 
 sympathetic nerves ; (8) Distribution of external carotid sympathetic nerves ; 
 (9) Distribution of cardiac sympathetic nerves; (10) Distribution of solar 
 sympathetic nerves; (11) Distribution of hypogastric sympathetic nerves. 
 18 
 
266 PRACTICAL ANATOMY. 
 
 TRANSMISSION OF PAIN. 
 
 1. Local in the organ supplied by the sympathetic. In this case the pain is 
 a sensation of heat, fullness, distress, tenderness, oppression, burning, weight, and 
 uneasiness. 
 
 2. Somatic. In this case the pain is reflected out over the somatic nerves 
 nearest to the sympathetic area supplying the irritated organ. This is indicated 
 by the arrows on the left. (Fig. 185.) 
 
 3. The long arrow indicates transference of pain from any of the visceral areas 
 through the gangliated sympathetic cord to the cranial nerves. In this manner 
 an ovarian, uterine, intestinal, or cardiac irritation may be even many times more 
 severe in the distribution of the fifth cranial nerve than at the seat of disease. 
 Through the auriculo-temporal branches of the fifth, pain in the scalp may be 
 reported. 
 
 ANATOMICAL CLASSIFICATION OF PAIN. 
 
 To aid t your memory and to teach you to be expert in tracing the transmis- 
 sion routes of pain from sympathetic system to somatic system, and to enable 
 you to determine, from the nature of the pain, whether a somatic or sympathetic 
 region is involved, learn the subjoined lists of adjective expressions, and study 
 carefully the preceding figure, showing in a comparative schematic manner the 
 respective distribution of somatic and sympathetic nerves. 
 
 CHARACTER OF PAIN IN THE SYMPATHETIC. 
 
 As the sequel will show, pain in the sympathetic nerve, pure and simple, is 
 designated by writers and lecturers on medicine by the following adjective 
 expressions : A sensation of weight, constriction, fullness, uneasiness, heat, dull- 
 ness, pricking, distress, tenderness, oppression, or burning. To be more explicit, 
 the above terms are used descriptively, while our task now is to show that in 
 those very diseases where these terms are used descriptively we find a sympa- 
 thetic nerve-supply only involved. 
 
 CHARACTER OF PAIN IN SOMATIC NERVES 
 
 ^-,,-f 
 
 Is designated by the following adjectives : Cutting, shooting, gnawing, dart- 
 ing, tearing, intense, sharp, severe, aching, griping, gnawing, boring, and fulgurat- 
 ing. It is our task here to show that where such pains occur a somatic area i 
 either pathologically involved or a somatic nerve is reporting pain that originate 
 in a sympathetic area. In other words, the character of the pain, as the sequ 
 will show, is a reliable index to the nature of the region involved by the pain 
 producing agent. 
 
 TABLE SHOWING COMMON DISEASES, 
 
 THE NATURE OF THEIR PAIN, WHEN LOCAL, AND THE NATUKK OF THKIK PAIN AND mi 
 ANATOMICAL ROUTE OF ITS TRANSMISSION, WHEN REFI.I \. 
 
 {Sympathetic pain, dull; when in center of lung, no pain. 
 Somatic pain, sharp and lancinating. 
 Reflex, lumbago on sound side. 
 Nerve route, via cardiac plexus and intercostal nerves. 
 r Sympathetic pain, heavy and uneasy. 
 p. i Somatic pain, intense, sharp, cutting, lancinating. 
 
 sy 1 Reflex, epigastric region, subaxilla, chest wall. 
 
 Nerve route, cardiac plexus and intercostals. 
 
ABDOMEN. 
 
 267 
 
 Bronchitis, 
 
 Pericarditis, .... 
 
 Endocarditis, . . . 
 
 Valvular Lesions, . . 
 
 Angina Pectoris, . . 
 
 Thoracic Aneurysm, 
 
 Renal Colic, 
 
 Aneurysm of 
 Thoracic Aorta, 
 
 Aneurysm of Abdom- 
 inal Aorta 
 
 Spinal Meningitis, 
 
 Locomotor Ataxia, . 
 
 Renal Inflammation, 
 
 Cancer of Stomach, . 
 
 .Gastric Ulcer, . . . 
 
 Intestinal Colic, . 
 
 i 
 
 \ 
 
 
 i 
 
 TABLE SHOWING COMMON DISEASES. (Continued?) 
 
 r Sympathetic pain, not severe, dull, heavy behind sternum. 
 
 j Somatic pain, sharp soreness, acute. 
 
 1 Reflex, epigastrium, short ribs. 
 
 v. Nerve route, cardiac plexus via intercostals. 
 
 Sympathetic pain, distress, in incipiency. 
 Somatic pain, acute, darting, paroxysmal. 
 Reflex, precordial tenderness and pain. 
 Nerve route, cardiac plexus via intercostals. 
 
 Sympathetic pain, distress rather than pain. 
 Somatic pain, acute when complicated by pericarditis. 
 Reflex, precordial tenderness and pain. 
 Nerve route, cardiac plexus via intercostals. 
 
 Sympathetic pain, constant and aching. 
 
 Somatic pain, darting, stabbing. 
 
 Reflex, chest, left shoulder, arm, forearm, ringers. 
 
 Nerve route, cardiac plexus via circumflex, internall cutaneous, ulnar. 
 
 Sympathetic pain, burning pain under sternum. 
 Somatic pain, intense and lancinating. 
 Reflex, chest, arm right, neck lower extremity. 
 Nerve route, cardiac plexus via somatic system. 
 
 Sympathetic pain, aching locally. 
 Somatic pain, intense and boring. 
 Reflex, back and chest. 
 Nerve route, cardiac plexus via intercostals. 
 
 Sympathetic pain, pricking locally. 
 
 Somatic pain, severe, excruciating. 
 
 Reflex, chest, abdomen, penis, testicles. 
 
 Nerve route, solar plexus via intercostals, internal pudic. 
 
 Sympathetic pain, local aching and burning. 
 Somatic pain, severe and radiating. 
 Reflex, chest walls and abdomen. 
 Nerve route, cardiac plexus via intercostals. 
 
 Sympathetic pain, heavy in back. 
 Somatic pain, intense in abdominal walls. 
 Reflex, abdominal walls. 
 Nerve route, solar plexus via intercostals. 
 
 Sympathetic pain, locally deap-seated and boring. 
 
 Somatic pain, severe and radiating. 
 
 Reflex, upper and lower extremities. 
 
 Nerve route, sympathetic and somatic systems. 
 
 Sympathetic pain, sympathetic ataxia. 
 Somatic pain, fulgurating pain in extremities. 
 Reflex, girdle pain in abdominal walls. 
 Nerve route, somatic and sympathetic. 
 
 Sympathetic pain, dull pain locally. 
 
 Somatic pain, severe, lancinating. 
 
 Reflex, penis, perineum, and testicle. 
 
 Nerve route, renal plexus via internal pudic nerves. 
 
 Sympathetic pain, locally gnawing. 
 
 Somatic pain, lancinating. 
 
 Reflex, absent in eight per cent, of recorded cases. 
 
 Nerve route, solar and vagus. 
 
 Sympathetic pain, burning and gnawing. 
 
 Somatic pain, pain often absent for days. 
 
 Reflex, epigastric tenderness. 
 
 Nerve route, solar plexus via intercostals. 
 
 Sympathetic pain, griping. 
 
 Somatic pain, severe character. 
 
 Reflex, epigastrium. 
 
 Nerve route, solar plexus via lower intercostal. 
 
 Sympathetic pain, uneasiness. 
 
 Somatic pain, tearing and cutting. 
 
 Reflex, umbilicus and right iliac regions. 
 
 Nerve route, solar plexus via lumbar plexus. 
 
 f S 
 S 
 
268 PRACTICAL ANATOMY. 
 
 TABLE SHOWING COMMON DISEASES. (Continued.} 
 i Sympathetic pain, dull and aching. 
 
 ., ^ ,- . i Somatic pain, umbilical tenderness. 
 
 Acute Enteritis, . . -< Reflex . doininal walls 
 
 ' Nerve route, solar plexus via lumbar plexus. 
 
 {Sympathetic pain, local burning. 
 Somatic pain, gnawing. 
 T" Q \~ A 1_ L J 
 
 Reflex, right nypochondrium. 
 Nerve route, solar plexus -via intercostals. 
 r Sympathetic pain, local pain set aside. 
 Intussusception, . . 3 Somatic pain, severe in umbilical region. 
 
 i Reflex, abdominal walls. 
 
 * V Nerve route, solar plexus via lower intercostals. 
 i- Sympathetic pain, set aside locally, or colicky. 
 
 Strangulated Hernia, \ S ? omatic P* in ' sev f re . umbilicus. 
 / Reflex, abdominal walls. 
 
 v Nerve route, solar plexus via intercostals. 
 r Sympathetic pain, dull locally. 
 Parenchymatous \ Somatic pain, mild somatically. 
 
 Hepatitis 1 Reflex, under right scapula, in shoulder. 
 
 v. Nerve route, solar plexus via circumflex and intercostals. 
 r Sympathetic pain ; when deep-seated, no pain. 
 Suppurative 1 Somatic pain, severe when superficial. 
 
 Hepatitis \ Reflex, right shoulder. 
 
 v Nerve route, solar plexus via circumflex nerve. 
 r Sympathetic pain, weight in right hypochondrium. 
 r - ... ) Somatic pain, very seldom any pain. 
 
 ' 1 Reflex, no reflex. 
 
 v. Nerve route, solar plexus via vagus. 
 
 r Sympathetic pain, darting in various directions. 
 
 ^ r T - * Somatic pain, severe. 
 
 Cancer of Liver, . . , Reflex Jg abdominal wa]ls 
 
 v. Nerve route, solar plexus via intercostals. 
 r Sympathetic pain, uneasiness and distress. * 
 Bili-vrv Calculi \ Somatic pain, severe, cutting, tearing. 
 
 ' ] Reflex, chest and abdomen. 
 
 v. Nerve route, solar plexus via intercostals. 
 Sympathetic pain, dull and distressing. 
 
 Ovaritis \ Somatic pain, severe and annoying. 
 
 Reflex, scalp, back, thigh. 
 
 Nerve route, hypogastnc plexus via fifth nerve, lumbar plexus. 
 
 
 Rationale of reflex pain and the anatomical factors involved in a simple 
 physiological reflex circuit. The rationale of reflexes is to be found in the law 
 of projectiles. Pain as a projectile having reached a transfer centre, pursues the 
 line of least resistance or the point of greatest traction. The factors involved in 
 a reflex circuit are : (i) A sensory nerve leading to a transfer centre. (2) A sen- 
 sory nerve leading from a transfer centre to a sentient area. 3. A transfer centre 
 communicating centrally with a sympathetic area, and peripherally with a somatic- 
 area. In figure 186 the pain is in the end of the penis; the disease is renal 
 colic. The sensory nerve to the penis, the internal pudic, a branch of the sacral 
 plexus ; the nerve-supply to the kidney is from the renal plexus. The pain is 
 more severe in the distribution of the somatic nerves than at the scat of th< 
 disease. 
 
 In like manner figure 186 shows the same. This \vc will then call a sen- 
 sory reflex pain, in which the pain is greatly exaggerated by its transmission 
 over the somatic part of the reflex circuit. A motor reflex pain may be repre- 
 sented in figure 187. Here also is a reflex circuit, the constituents of which are 
 (i) a sensory nerve ; (2) a motor nerve ; (3) a transfer centre. The phenomena 
 produced are called motor reflexes. 
 
 Kemembcr, these schematic figures are introduced here, not for the purpose 
 
 is 
 
 : 
 
ABDOMEN. 269 
 
 of attempting to teach the physiology of reflexes, but simply to impress on the 
 student the imperative necessity of being able, in dissection, to show the place 
 where somatic and sympathetic nerves communicate, by the ncrvi comniunicantes. 
 
 Is there any difference in the traiismissional power of souiatie and sn/ipathetic 
 nerves / 
 
 From the decided difference in the character of pain reported by these two 
 nerves we would conclude there is a difference. 
 
 Wliat is the difference in tran smissional power / 
 
 This is conjectural only. Simply to aid the memory, we might view the 
 subject in the light of logical reasoning. For physiological facts, however, you 
 must consult physiologists. Structure is the correlative of function ; hence, 
 m.irked differences in function entail consequent marked differences in structure. 
 
 Renal Plexus 
 
 y ntdney - 
 
 Renal Colic 
 
 X &reter. Bladder, Lumbar and Penis reflex ar*>. 
 
 Cardiac Plexus 
 
 X -X Heart 
 
 -X Arm, Finyers, Shoulder and Abdominal Wall* 
 
 Cardiac Plexus L 
 
 n y 
 
 -X- 
 
 Pneumonia 
 
 1 Pain in Lumbar ret/ton 
 
 2 Pain in the Kpigasfrum 
 .? Pain on the sound side 
 
 Pelvic Plexus ^^- Ovaritis 
 
 x <C^ Salpinailts 
 
 Back ^~^^Displacements 
 
 X Chest 
 
 Extremities - Tfie reflex areas frequently 
 
 (iastric Plexus 
 x y Stomach 
 
 nd Cancer 
 X Abdominal Walls, TTie reflex area 
 
 ffypogastric Plexus 
 
 y ffites tine - 
 
 Enterataia 
 
 'liacreyion end Umbilicus , The. reflex area 
 
 FIG. 186. SHOWING SCHEMATICALLY A SENSORY REFLEX CIRCUIT. 
 
 The converse is true. The sympathetic individual fibre is smaller ; its fibres 
 undergo numerous interruptions, not only in the ganglia of the gangliated cord, 
 but also in numerous other plexuses, of which the plexuses of Auerbach and 
 Meissner may be taken as the type. 
 
 Somatic and sympathetic nerves are routes by which nerve-impressions travel. 
 Nerve-impulses, of whatever kind, are, then, projectiles, and amenable to the law 
 of projectiles : " Projectiles follow the line of greatest traction, the point of 
 least resistance, or the resultant of the two." If, then, the small calibre of 
 sympathetic nerves, and their frequent interruptions, form a resistance to nerve- 
 impulses, then somatic nerves, possessing neither of these assumed impedi- 
 ments, logically furnish lines of least resistance. 
 
 Our conclusion would be, then, that in the case of a given irritation in a sym- 
 pathetic area, as in cardiac valvular lesion, the sympathetic reports the pain to 
 
270 PRACTICAL ANATOMY. 
 
 the cardiac plexus ; this plexus, however, transmits the impulse to the nearest 
 somatic nerves, which greatly intensify the pain, and refer the same, peripher- 
 ally, to the chest, left shoulder, forearm, and fingers, by the intercostals, 
 descending branches of the cervical plexus, internal cutaneous, median, ulnar, 
 and radial nerves. Thus, a pain that was reported as simply "aching," in the 
 locality of the lesion, under poor transmissional conditions, becomes, under the 
 better transmissional conditions of somatic nerves, a pain dartijig, stabbing, and 
 excruciating. 
 
 Branches of the Abdominal Aorta and Sympathetic Nerves. I now 
 desire you to dissect the branches of the abdominal aorta with special reference 
 to the sympathetic nerves. This is logical, since the sympathetic accompanies 
 every artery to its visceral end, takes the very name of the artery, and regulates 
 the amount of blood each organ shall receive, both in health and disease. The 
 sympathetic reports to the cortical sensory areas in the cerebrum sensations, both 
 of pain and well-being, through the vagus and all the spinal nerves. It carries 
 on the function of organs during suspension of volition. 
 
 The following explanation of arrangement will give you a clear idea of the 
 meaning of terms. Before you proceed further, master this scheme : 
 
 i. Every artery is surrounded by a plexus of small nerves, which accompany 
 the artery in all its branches to the organ supplied by the artery. 
 
 Sensory N.5* < 
 
 Moto 
 
 6 Sensory Branches of Anterior Crural * -^^ 
 
 ) ^>x Patella 
 
 I Motor of Anterior Crural > ^^^^ 
 
 Motor t/ie 7?A ,. 
 
 X face 
 
 FIG. 187. SHOWING SCHEMATICALLY A MOTOR REFLEX CIRCUIT. 
 
 2. This plexus, which always takes the name of the artery it accompanies, 
 has its origin in a ganglion near the beginning of the artery on the aorta ; the 
 plexus also takes the name of the artery which its branches accompany. 
 
 3. The ganglion /. e., all the ganglia situated at the beginning of all the 
 branches of the abdominal aorta is fed by nerves from the solar plexus. 
 
 4. The solar plexus is situated in front of the beginning of the abdominal 
 aorta. It consists of two large semilunar ganglia, which embrace the co-liac 
 axis. The two ganglia are connected both above and below the artery which 
 they embrace. The plexus is formed by branches from the vagus, uniting here 
 with the sympathetic. In this way, then, may be explained the manner in which 
 the vagus reaches all the abdominal organs with motor fibres. 
 
 5. The solar plexus, then, is that part of the sympathetic nerve from which 
 all the abdominal viscera derive their nerve-supply. It is situated high, but is 
 prolonged downward under the name of the aortic plexus. From this the gan- 
 glia situated at the beginning of the branches of the aorta take their origin ; 
 these ganglia throw off plexuses which accompany the artery. The solar plexus 
 is a sort of clearing-house for the abdominal sympathetic nerves. 
 
 6. From above down, then, the succession of names is as follows : (i) '1 he 
 solar plexus, formed of two semilunar ganglia; (2) the dowmvard prolong- 
 
ABDOMEN. 
 
 271 
 
 tion of the solar plexus, called aortic plexus ; (3) ganglia situated at the origin 
 of every artery from the aorta, which take the name of the aorta ; (4) branches 
 or plexuses from the ganglia, which take also the name of the artery and accom- 
 pany the same to its distribution. 
 
 In view of the foregoing, you are prepared now to find, locate, explain, and 
 understand : 
 
 1. Diaphragmatic artery, nerves, plexus, ganglion, and vein. 
 
 2. Splenic artery, nerves, plexus, ganglion, and vein. 
 
 3. Hepatic artery, nerves, plexus, ganglion, and vein. 
 
 4. Gastric artery, nerves, plexus, ganglion, and vein. 
 
 5. Suprarenal artery, nerves, plexus, ganglion, and vein. 
 
 6. Renal artery, nerves, plexus, ganglion, and vein. 
 
 7. Spermatic artery, nerves, plexus, ganglion, and vein. 
 
 8. Ovarian artery, nerves, plexus, ganglion, and vein. 
 
 9. Superior mesenteric artery, nerves, plexus, ganglion, and vein. 
 10. Inferior mesenteric artery, nerves, plexus, ganglion, and vein. 
 Dissection of the above nerves requires care. Work in the direction of the 
 
 Aorta 
 
 SOLAR PLEXUS, THE ABDOMINAL 
 CLEARING-HOUSE FOR THE 
 SYMPATHETIC NERVE 
 
 c artery, large 
 SYMPATHETIC NERVE, CALLED MESENTERIC 
 
 A MESENTERIC GANGLION ON THE AORTA 
 
 FIG. 1 88. To SHOW RELATION OF ABDOMINAL SYMPATHETIC NERVES TO (i) SOLAR PLEXUS 
 
 AND (2\ TO THE GANGLION AT THE R()OT OF THE ARTERY. 
 
 vessel, with forceps. Consult the figures heretofore given to find name and 
 location of vessels. For solar and aortic plexuses see figure 186. 
 
 Make special note : (i) The renal veins lie in front of their arteries, thereby 
 forming an exception to the rule governing the relation of arteries to veins. (2) 
 The left spermatic vein opens into the left renal vein, and this latter passes in front 
 of the aorta. (3) The right spermatic vein opens into the ascending vena cava just 
 below the renal. (4) The ovarian veins follow the course of their homologues. 
 (5) The spermatic arteries arise from the aorta below the renals, pass in front of 
 the ureter about opposite the bifurcation of the aorta. The ovarian take the 
 same course. (6) The four lumbar arteries are analogous to the intercostals. 
 (7) The ureteric arteries accompany the ureters ; they are branches of the common 
 iliac and superior vesicle. (8) The arteries to the vas deferens, to the urachus, and to 
 the ureter are branches of the superior vesicle. (9) The sacra media, the smallest. 
 
 Essential Points on the Sympathetic. You have traced out the branches 
 of the abdominal aorta, and I trust you now understand the principle under- 
 lying the distribution of visceral nerve-branches, from one abdominal prevertebral 
 plexus the solar plexus. We shall find in the pelvis, likewise, organs receiving 
 arteries ; these arteries will be accompanied by sympathetic nerves ; these nerves 
 
272 
 
 PRACTICAL ANATOMY. 
 
 GANGLION DIAPHRA GM. I IK 7 M/ 
 
 SUPRARENAL 
 CAPSULE 
 
 ORE A T 8 PL A NCH- 
 
 NIC NER VE 
 RIGHT SEMI LU- 
 NAR GANGLION 
 
 RENAL GANGLION 
 
 SMALL SPLANCHNIC 
 NERVE 
 
 Renal artery 
 
 GANGLIA TED CORD 
 
 RAMUS COMMUNICANT 
 
 Hepatic artery 
 
 BRANCH TO AORTIC 
 PLEXUS 
 
 LEFT SEMI LU- 
 NAR GANGLION 
 
 (iHF.AT 
 
 -V/r NJ- 
 
 SMA LL SI'LA S< 'II- 
 
 Superior mesenteric 
 artei-y 
 
 RENAL GANGLION 
 
 Renal artery 
 
 SUPERIOR MESENTERIC 
 GANGLION 
 
 BRANCH TO AORTIC 
 PLEXUS 
 
 GANGLIA TED CORD OF 
 SYMPA THETIC 
 
 Inferior mesenteric artery 
 
 INFERIOR .V/'N/'.v- 
 TERIC GANGLION 
 
 Disc between last lumbar 
 and first sacral vertebra 
 
 ('mil until ilinc rt in 
 Common iliac artei-y 
 
 IMC. I.S<J. I.CMIiAU I'OKTHIN 01 I1IK ( i ANCI I \TKI > CORD, WITH Till. Soi.AK AM' I I V l'( )CAS IK U 
 
 I'l.KXCSKS. (I It-Ill.', i 
 
ABDOMEN. 273 
 
 will come from plexuses on the artery ; these plexuses will originate in ganglia 
 near the origin of the artery ; they will take the name of the artery and trace 
 their own origin to the hypogastric plexus. We shall find, in the thorax, the 
 heart and lung concerned in the circulation of the blood and its purification 
 respectively. These organs receive their nourishment through arteries, and 
 their arteries are attended by nerves, which nerves have their origin in plexuses ; 
 these plexuses spring from ganglia near the origin of the artery, and these 
 ganglia trace their own origin to the cardiac plexus. 
 
 There is, then, one great sympathetic depot for the organs in the thorax, called 
 cardiac pie. rus ; one in the abdomen, called solar plexus ; one in the pelvis, called 
 hypogastric plexus. This arrangement is simply to make possible a physiological 
 division of labor. Remember, then : the manner of distribution of sympathetic 
 nerves is always the same in every region of the body ; branches, plexuses, and 
 ganglia take the name of the artery ; there are three large plexuses (i) cardiac, 
 (2) solar, (3) hypogastric ; there are as many small plexuses as there are 
 arteries to supply viscera and these small plexuses all draw their influence 
 from the three large plexuses. 
 
 In view of what we have found, and what we shall find, let us gain a general 
 idea of the sympathetic system in the following questions and answers : 
 
 1. Is the sympathetic a system, separate and entire, and independent of the 
 ccrebro-spinal ? 
 
 No ; sympathetic nerves are only nerves, branches of the spinals, set aside 
 to supply organs. 
 
 2. Of ivhat docs ttic sympathetic system consist f 
 
 (i) Of gangliated cord, in the form of a horse-collar, communicating on the 
 anterior communicating artery above and on the coccyx below ; (2) of spinal 
 branches, called rami communicantes two from each spinal nerve ; (3) of three 
 prevertebral plexuses cardiac, solar, and hypogastric ; (4) of branches of distri- 
 bution ; (5) of plexuses and ganglia that take the name of the arteries on which 
 found. 
 
 3 . Can iv e see the nerves and ganglia / 
 
 Yes ; in the thorax behind the pleura, and located opposite the heads of the 
 ribs, you can seethe ganglia ; you can also find the two communicating branches 
 from the spinal nerves ; also the cord extending from one nerve to another. 
 
 The Hypogastric Plexus. In the lumbar region you will find the gangli- 
 ated cord on the front of the bodies of the vertebrae, along the inner margin of 
 the psoas magnus. You can trace branches to the lumbar nerves behind the 
 psoas magnus. You will see numerous branches from the lumbar cords, uniting 
 with branches coming down from above to form the hypogastric plexus. This 
 is between the common iliac arteries and passes down to form the pelvic plexus. 
 
THE PELVIS. 
 
 DISSECTION OF THE PELVIS. 
 
 Inspect and become familiar with the following : 
 
 1. The pelvic contents are covered by peritoneum. 
 
 2. The rectum is on the posterior wall of the pelvis. 
 
 3. The bladder is on the anterior wall of the pelvis. 
 
 4. The obturator nerve and vessels are on the outer wall. 
 
 5 . The ureter crosses into the pelvis and can be seen. 
 
 6. The uterus and adnexa are between bladder and rectum. 
 
 7. The broad ligament contains the uterine adnexa. 
 
 8. The recto-vesical poucli is between the rectum and bladder. 
 
 9. The peritoneum does not cover the anterior surface of bladder. 
 
 10. Retzius' space is between bladder and pubes. 
 
 1 1. The recto-vaginal, recto-uterine, and cul-de-sac of Douglas. 
 
 12. Douglas' cid-de-sac is between the rectum and vagina and uterus. 
 
 13. Ilciun and great ojnentum gravitate into the pelvis. 
 Follow this order in your dissection : 
 
 1 . The peritoneal ligaments of the bladder, rectum, and uterus, and the 
 sympathetic nerves from the pelvic part of the hypogastric plexus to the same 
 viscera, noticing they invariably follow the arteries to the organ, and take the 
 name of the artery. 
 
 2. The pelvic fascia and its subdivisions and modifications incident to use, 
 remembering, as you must, that growth is the correlative of function. Notice, 
 too, that pelvic fascia is condensed subperitoneal connective tissue. The upper 
 or uncondensed portions of the pelvic fascia contain fat. 
 
 3. Study the relations of the psoas carefully ; as nearly as may be, follow 
 the steps just as given in the sequel, for this is the order in which you will meet 
 all these various structures in your dissection. 
 
 4. The lumbar plexus ; its location in the substance of the psoas muscle ; its 
 formation by the four upper lumbar nerves and a communicating branch from 
 the twelfth thoracic ; and its immense distribution. 
 
 .5. The internal iliac artery and all its branches, where the same escape froi 
 the pelvis, the spinal nerves they accompany, and the source of the sympathetic 
 nerves that encircle them to supply the viscera. 
 
 6. A view of the ischio-rectal fossa from above, by cutting the origin of the 
 levator ani muscle at the white line and looking in on the obturator interims 
 muscle that forms its outer wall. 
 
 7. The sacral plexus, its location, relations, communications, and branches 
 distribution, and where these large branches escape from the pelvis. 
 
 8. In addition to the above, make dissection and study of the iliacus (origin 
 of), the pyriformis, the levator ani, the obturator interims, the white line of the 
 pelvis, and the delamination in the obturator fascia, called Alcock's canal. 
 
 In order to estimate the peritoneal ligaments in any peritoneal region, asl 
 yourself how many viscera of considerable size grew up behind this membram 
 
 274 
 
THE PELVIS. 275 
 
 and pushed the same before themselves. In the pelvis, the bladder, rectum, and 
 uterus grew up and developed behind the peritoneum ; hence, not only are these 
 three structures behind the peritoneum, but all their adnexal parts as well ; they 
 are held in position more or less by the peritoneum, and those processes having 
 one end on the organ and the other fixed to a wall are called the peritoneal 
 ligaments of these organs. Inflate the bladder, and see, posteriorly, two folds 
 extending from the rectum to the bladder ; also a fold on each side from the iliac 
 fossa to the side of the bladder. The plica urachi is the superior ligament of the 
 bladder. The peritoneal ligaments of the bladder are tivo posterior, two lateral^ 
 and one superior. 
 
 The Rectum. -The rectum begins at the pelvic brim, opposite the left sacro- 
 iliac synchondrosis. You will ligate and cut the same at this point, leaving the 
 sigmoid in situ. Notice that the upper part of the rectum has a fold of peri- 
 toneum the meso-rectum. The next stage of the rectum is partially covered 
 by peritoneum, like the descending colon. The lower part of the rectum, one 
 and one-half inches in length, and extending from the tip of the coccyx to the 
 anus, has no peritoneum, as you will see on the cadaver. Now search beside 
 the rectum and bladder and you will find the pelvic plexus of sympathetic 
 nerves, which supplies all the viscera in the pelvis. Here, as elsewhere, the 
 nerves accompany the arteries to the parts and take the same name. 
 
 The pelvic fascia is the lower condensed layer of the subperitoneal connec- 
 tive tissue. It takes the following different names : iliac, obturator, recto-vesical,. 
 pubo-prostatic, anal, white line, Alcock's canal according to its location. The 
 white line you will see extending from the ischial spine to the pubic bone, one 
 inch below the subpubic arch. It is a split in the obturator fascia, from which 
 split arises the levator ani muscle. (Fig. 192.) The anal fascia covers the under 
 surface of the levator ani muscle. The recto-vesical fascia extends across the 
 upper surface of the levator ani muscle, investing the rectum and bladder. It 
 also extends from the pubes to the neck of the bladder and prostate, under the 
 name of pubo-prostatic. Demonstrate all these on the cadaver. 
 
 The iliac fascia covers the iliacus muscle, passes out of the pelvis behind 
 the femoral vessels, and unites with the transversalis fascia by the side of the 
 femoral vessels to form the femoral sheath, as described on page 235. 
 
 The obturator fascia covers the obturator internus muscle and delaminates 
 to form the wJiite line. (Fig. 192.) 
 
 Relations of the Psoas Magnus Muscle. (i) Lying on the muscle you see 
 the psoas parvus ; (2) to the outer side, see the iliacus muscle and the anterior 
 crural nerve ; (3) to the inner side, skirting the pelvic brim, the common and exter- 
 nal iliac arteries are seen ; (4) to the inner side, and one-half of an inch below the 
 pelvic brim, see the obturator nerve and vessels ; (5) emerging from the front sur- 
 face of the middle third of the muscle, see the external cutaneous nerve ; (6) to 
 the inner side, between the muscle and the common iliac artery, see the genito- 
 crural nerve ; (7) to the outer side of the muscle, above, see the last thoracic, the 
 ilio-kv pogastric , and the ilio-fnguinal nerves ; (8) in the substance of the muscle, 
 this having been detached and removed piecemeal with the forceps from within 
 outward, see the lumbar plexus, giving off the following branches. 
 
 Branches of the Lumbar Plexus (Fig. 190). Dissection : 
 
 1. I lio-Jiy pogastric, to the skin over the gluteus maximus and over the hypo- 
 gastrium ; lies between the internal oblique and transversalis ; communicates 
 with the last dorsal. The hypogastric branch pierces the aponeurosis of the 
 external oblique muscle one inch above the external abdominal ring, and is dis- 
 tributed to the skin over the region of the bladder. 
 
 2. Ilio-inguinal, crosses the quadratus and iliac muscles, pierces the trans- 
 versalis, lies between the internal oblique and transversalis, supplies the internal 
 
276 
 
 PRACTICAL ANATOMY. 
 
 oblique, lies in front ot the spermatic cord in the inguinal canal, escapes by the 
 external abdominal ring, and supplies the scrotum and inner side of the thigh. 
 
 3. Gcnito-erural, descends on the front surface of the psoas magnus, divides 
 into a genital and a crural branch ; the genital branch enters the internal abdom- 
 inal ring, lies behind the spermatic cord, and is distributed to the cremaster mus- 
 cle. In the female it goes with the round ligament, supplies the same with 
 motion, and is lost in the labia majora. 
 
 4. The crural branch of this nerve descends on the external iliac artery, lies 
 in the femoral sheath, and is distributed to the skin covering the insertion of the 
 psoas according to Hilton's law. 
 
 GANGLIATED CORD OF SYMPATHETIC 
 LAST THORACIC NERVE 
 
 FIRST LUMBAR 
 
 ILIO- 
 
 HYPOGASTRIC 
 ILIO-INGUINAL 
 
 SECOND 
 LUMBAR 
 
 FOURTH 
 
 LUMBAR 
 
 ILIO-INGUINAL 
 
 EXTERNAL 
 
 CUTANEOUS 
 
 GENITO-CRURAL 
 LUMBO-SACRAL 
 
 CORD 
 
 ANTERIOR CRURAL 
 OBTURATOR 
 
 OBNTTAl. BRANCH 
 OF OEXITO-CRURAL 
 
 CRURAL BRANCH OP 
 GEXITO-CRURAL 
 
 ILIO-INGUINAL 
 
 DISTRIBU- 
 TION OF 
 EXTERNAL 
 CUTANEOUS 
 
 CRURAL 
 BRANCH 
 OF GENITO- 
 CRURAL 
 
 AORTIC PLEAT* 
 
 LAST THORA CIC NER VE 
 
 ILIO-HYPO- 
 QA8ZRIC 
 
 INGUINAL 
 
 THIRD 
 LUMBAR 
 
 GENITO- 
 CRURAL 
 
 EXTERN A L 
 CUTANEOUS 
 
 GENITAL 
 BRANCH 
 OF 
 
 GENITO- 
 CRURAL 
 
 CRURAL 
 HKA.\CH OF 
 (i KM Til 
 CRUMAL 
 
 ourr- 
 
 RATOl 
 
 FIG. 190. BRANCHES OK TIIK I,t MI.AR AND SACRAL PLEXUS, VIIAVKK i ROM BEFORE, 
 (After Hirschfeld and Leveilte.J 
 
 5. External cutaneous, emerges from the outer side ot psoas, crosses iliacus 
 under the iliac fascia, leaves pelvis under crural arch, below anterior superior 
 spine of ilium, pierces deep fascia of thigh, and supplies skin over outer side of 
 thigh, being a dismembered branch of the anterior crural nerve, in reality. 
 
 6. Obturator, emerges from psoas on inner side, lies on outer wall of pelvi 
 leaves pelvis by obturator foramen, divides into .anterior and posterior divisions, 
 separated by the adductor brevis muscle ; the anterior division communicates with 
 the internal cutaneous and long saphcnous nerves, forming the subsartori 
 plexus for the supply of the skin over the insertion of the adductors llilto 
 
 01 
 
 ,. 
 
THE PELVIS. 
 
 277 
 
 laic. It then supplies the gracilis, adductor longus, adductor brevis, and sar- 
 torius. The posterior division supplies the hip, knee, obturator externus, and ad- 
 ductor magnus. 
 
 7. Accessory obturator often absent ; when present it lies to the inner side of 
 the psoas, passes under outer border of pectineus, supplying this muscle and the 
 hip-joint. 
 
 Common iliac artery 
 SYMPA THE TIC NER YE 
 
 Middle sacral artery 
 \ 
 
 Common iliac vein 
 
 URETER 
 
 Internal iliac artery 
 
 External iliac vein 
 External iliac artery 
 
 Posterior branch of internal iliac dividing into 
 gluteal <tn<l ilitj-ltitnbar arteries 
 
 Lateral sacral arte 
 
 SACRAL PLEXUS 
 OBTURA TOR NERVE 
 
 Obturator artery 
 Obliterated hypogastric 
 
 Superior vesical artery 
 Edge of levator ani 
 
 Pudic artery 
 
 BLADDER 
 
 Middle vesical artery 
 
 Deep epigastric artery 
 Pubic branch, of epi- 
 gastric artery 
 Common femoral artery 
 
 Long saphenotis vein 
 Pectineus muscle 
 
 Obturator artery 
 
 Adductor magnus 
 
 Internal circumflex artery 
 
 Adductor brevis 
 
 OBTURATOR NERVE (ant. branch) 
 
 Profunda artery 
 
 Adductor longus, hooked aside 
 
 Superficial femoral artery and vein 
 
 Gracilis muscle 
 Lower part of sartorius 
 
 Fsoas muscle 
 Ilio-lumbar artery 
 
 EXTERNAL CUTA- 
 NEOUS NERVE 
 
 Iliacus muscle 
 
 , GENITO-CRURAL 
 44- NER VE 
 
 ANTERIOR CRU- 
 RAL NERVE 
 
 Deep circumflex iliac 
 
 artery 
 Superficial circumflex 
 
 iliac artery 
 
 ANTERIOR CRL'RAL ff. 
 Gluteal artery and 
 
 Tensor taciae femoris 
 
 (hooked aside) 
 Gluteus medius and 
 
 minimus 
 Sartorius muscle 
 MIDDLE CUTA- 
 NEOUS NERVE 
 
 NER VE TO RECTUS 
 
 NERVE TO VA STL'S 
 ESTERXUS 
 
 External circumflex ar, 
 
 NERVE TO CRCREUS 
 -J^a Rectus, hooked aside 
 T~V Profunda vein 
 
 LONG SA PHENOL'S 
 NERVEAND 
 NERVE TO VAS- 
 TUS INTERNUS 
 
 Vastus internus 
 muscle 
 
 FIG. 191. SIDE VIEW OF PELVIS AND UPPER THIRD OF THIGH, WITH THE EXTERNAL ILIAC, 
 
 INTERNAL ILIAC, AND FEMORAL ARTERIES AND THEIR BRANCHES. 
 
 (From a dissection by W. J. Walsham in the Museum of St. Bartholomew's Hospital.) 
 
 The bladder is hooked over to expose back of pelvis. 
 
 8. Anterior cniral, emerges between the iliacus and psoas muscles, under 
 crural arch or Poupart's ligament, lies in a groove between these muscles under 
 the iliac fascia ; it gives off the internal cutaneous, middle cutaneous, and long 
 saphenous branches. Its muscular branches are to the sartorious, rectus femoris, 
 vastus internus, vast us externus, and crureus. The branches to the vasti also 
 send filaments to the knee-joint ; the branch to the rectus sends a filament to the 
 hip-joint Hilton's law. 
 
 9. T/tc lumbar nerves send ranii coinuiiinicantes to the hypogastric plexus. 
 
2 7 8 
 
 PRACTICAL ANATOMY. 
 
 10. The dorsi-lumbar cord is the communication of the first lumbar with the 
 last thoracic nerve ; the himbo-sacral cord is the communication of the lumbar 
 plexus with the sacral plexus. Find these two cords on the cadaver. 
 
 Dissection of the Internal Iliac Artery (Fig. 191). The common iliac artery 
 divides into the internal and external. Use only the forceps when you develop 
 branches of vessels. Follow the direction of the artery and its branches as they 
 are given off, and find : 
 
 1. The ureter, crossing into the pelvis at the bifurcation of the common iliac 
 artery, and its small ureteric in its sheath. 
 
 2. The bladder being inflated, find the three vesical arteries superior, middle, 
 
 Aperture for 
 
 superior gluteal 
 vessels and nerve 
 
 Aperture for 
 sciatic and pudic 
 vessels and nerve 
 
 Coooygeal fibres of 
 levator ani 
 
 Fibres of leva- 
 tor ani 
 
 Sphincter ani 
 RECTUM 
 
 White line ' of 
 obturator fascia 
 
 Pubic attachment 
 of levator ani 
 
 Tendinous centre 
 of periuitum 
 
 FIG. 192. MUSCI.KS OF 'fiiK FLOOR OK THK PKLVIS. 
 (A portion of the ischial and pubic bones sawn away.) 
 
 and inferior. In connection with the superior vesieal, find the obliterated Jiy t 
 gastric artery. 
 
 3. Find also the middle luemorrlioidal, to the rectum, in company with syt 
 patlictie nerves from the pelvic plexus. 
 
 4. Find the uterine artery ( Fig. 204) passing between the folds of the brc 
 ligament of the- uterus. 
 
 5. Find the -vaginal arteries, three or four in number, anastomosing wit 
 die another and with the uterine. 
 
 6. Trace the ilio-lnmbar between the psoas magnus and vertebral columi 
 at this point see it divide into an iliac and a lumbar branch. 
 
THE PELVIS. 279 
 
 7. Trace out the lateral sacrals to the spine and front of the sacrum. 
 
 8. Follow the superior gluteal out of the pelvis above the pyriformis, 
 through the greater sacro-sciatic foramen, with a nerve of the same name. 
 
 9. Follow the obturator vessels below the obturator nerve through the 
 obturator foramen to the adductor muscles. 
 
 10. Observe the internal pudic leave the pelvis by the greater sacro-sciatic 
 foramen below the pyriformis, cross the ischial spine, reenter the pelvis by the 
 lesser sacro-sciatic foramen, and pass through Alcock's canal to supply the 
 external organs of generation in both the male and female. This artery is 
 attended in its course by the internal pudic nerve. 
 
 1 1. The sciatic artery is a large and important vessel. It crosses the pyri- 
 formis muscle and sacral plexus and leaves the pelvis by the greater sacro- 
 sciatic foramen below the pyriformis muscle, in company with the internal pudic 
 and sciatic nerves. The artery lies under the gluteus maximus muscle and on 
 the external rotation of the thigh. It gives off the inferior gluteal artery, which 
 anastomoses with the superior, and also branches to the pelvic floor and pelvic 
 viscera ; branches to the rotator muscles, and the arteria comes nervi ischiadici, 
 a branch that accompanies the great sciatic nerve. This artery completes the 
 crucial anastomosis, an important collateral circulation about the hip-joint, by 
 inosculating below with the first perforating branch of the profunda, with the 
 internal circumflex internally, and with the external circumflex externally. 
 
 The sympathetic distribution in this region will correspond to the visceral 
 branches given off from the internal iliac artery. The bladder will receive its 
 supply by the vesicals ; the uterus by the uterine ; the ovary by the ovarian ; 
 the rectum by the hemorrhoidals superior, middle, and inferior ; the urethra and 
 erectile tissue of penis and clitoris by the internal pudic. Remember the order : 
 (i) nerve; (2) plexus; (3) ganglion. All trace their sympathetic influence to 
 that part of the sympathetic located in the pelvis, by the side of the bladder, rec- 
 tum, vagina, and uterus the pelvic plexus. 
 
 The Obturator Internus. Cut through the levator ani muscle the whole 
 length of the white line, from spine of ischium to pubic bone ; you may now look 
 down into the ischio-rectal fossa, and see the obturator internus muscle covered 
 by the obturator fascia, forming the outer wall of this fossa ; you can now appre- 
 ciate the origin of the levator ani from the white line and the cut segment of the 
 muscle, and study both the inner and outer walls of the ischio-rectal fossa. (Fig. 
 192.) You will also detach the pyriformis, at its origin, from the anterior surface 
 of the sacrum. Observe it passing through the greater sacro-sciatic foramen. 
 You will also see the coccygeus muscle extending from the spine of the ischium to 
 the side of coccyx. Now find on the outer wall of the ischio-rectal fossa, in 
 Alcock's canal, the internal pudic structures ; trace the same forward and see the 
 relation they bear to the tuber ischii and the triangular ligament, where they 
 perforate the posterior layer of this latter, to enter the deep perineal space. 
 
 The ischio-rectal fossa is bounded by the obturator internus muscle exter- 
 nally, by the levator ani internally ; its apex is at the white line ; it extends from 
 the pubic bone in front to the sacrum behind ; the base is formed by the skin and 
 fasciae. When you dissect the pelvic outlet, you approach this fossa from the 
 base. In the present dissection, however, you approach the fossa from above. 
 When you cut through the white line, you opened into the fossa. You then 
 pulled the levator ani muscle to the mid-line ; this levator ani muscle with 
 its investing anal fasciae, above and below, is the inner wall of the fossa, and 
 you are thus permitted to see the outer wall of the fossa the obturator internus 
 musc le covered by the obturator fascia. 
 
 Iliacus Muscle. Detach this muscle from its extensive origin in the iliac 
 fossa, and find under the same the iliac branches of the ilio-lumbar artery a 
 
280 
 
 PRACTICAL ANATOMY. 
 
 branch of the internal iliac artery. Find the groove between this muscle and 
 the psoas, containing the anterior crural nerve. 
 
 Dissection of Sacral Plexus (Figs. 193 and 194). Cut through the symphysis 
 pubis and pull outward on both pubic bones, and separate the ilium from the 
 sacrum, at the sacro-iliac synchondrosis. Then study the following points : 
 
 1. The plexus is located on the posterior pelvic wall. 
 
 2. It rests on the pyriformis muscle. 
 
 FROM LAST THORACIC 
 
 GENITO-CR URA L 
 
 ILIO-HYPOGASTRIC 
 
 ILIO-INGUINAL 
 
 EXTERNAL 
 CUTANEOUS 
 
 OBTURATOR 
 
 A CCESSOR Y 
 OBTURA TOR 
 
 BRANCH TO ILIACUS 
 ANTERIOR CRURAL 
 
 SUPERIOR GLUTEAL 
 INFERIOR GLUTEAL 
 
 GREAT SCIATIC 
 
 NERVE TO 
 
 qUADRATUS 
 
 FEMORIS 
 
 EXTERNAL 
 
 POPLITEAL 
 
 SECTION 
 
 INTERNAL 
 POPLITEAL 
 
 SM'TION 
 
 FIRST L I'M HA R 
 
 SECOND L UMBA R 
 
 THIRD LUMBAR 
 
 FO UR TH L UMBA R 
 
 , FIFTH LUMBAR 
 
 FIRST SACRAL 
 
 SECOND SACRAL 
 
 THIRD SACRAL 
 
 VISCERAL 
 Fornril SACRAL 
 
 PERFORA 77 v; 
 
 i -i y.i.\7:or.v 
 PERIN.KAL 
 FIFTH SACRAL 
 
 NEKVK TO I'OfCYHKl-f! 
 
 NER VE TO LEVA TOR 
 AN! 
 
 FIRST COCCYCI-AL 
 
 VISCERAL 
 
 TO HAMSTRINGS 
 
 SMA LL SCI A TIC P UDIC 
 
 NERVE TO OBTURATOR INTERN US 
 
 FIG. 193. DIAGRAM OF THE LUMBAR AND SACRAL PLEXUSES. Modified from Taterson. 
 
 3. It is covered by the pelvic fascia and peritoneum. 
 
 4. It is crossed by the internal iliac vessels. 
 
 5. The gluteal and sciatic arteries transfix it. 
 
 6. It receives the fifth and part of the fourth lumbar nerves. 
 
 7. The part received from the lumbar is called the lutnbo-sacmil cord. 
 
 8. The tacral [>lc.\ v/.v is formed by the union of the lumbo-sacral cord and 
 the anterior primary divisions of the first, second, third, and a part of the fourth 
 sacral nerves. 
 
 
THE PELVIS. 
 
 281 
 
 9. This union is called s"acral plexus to the lower margin of the greater sacro- 
 sciatic foramen, where it continues its course under the name of great sciatic nerve.. 
 
 10. The sacral nerves all send rami communicantes to the pelvic sympathetic 
 plexus, which you have already found, located to the inner side of the anterior 
 sacral foramina, by the side of the rectum and bladder. 
 
 Dissection : (i) Trace the first, second, and third sacral nerves as far into the 
 sacral foramina as possible. Notice ! This must be done with a blunt forceps, 
 
 Hit" Dura mater of . 
 
 LAST TIIORA CIC NER VE 
 
 ILIO- 
 HYPOGASTRIC 
 
 77,70- 
 INGU1NAL 
 
 ILIAC BRANCH 
 
 OF 1LIO- 
 HYl'OGASTRIC 
 
 Gluteus medius 
 
 Gluteal artery 
 SUPERIOR 
 GLUTEAL NERVE 
 
 ORE A T SCIA TIC NER VE 
 
 INFERIOR GLUTEAL 
 NER VE 
 
 SMALL SCIA TIC NER VE 
 
 POSTERIOR PHI1UAHF 
 DIVISION 
 
 GENITO-CRURAL 
 
 GAUD A EQUINA 
 
 Pilum terminate 
 
 EXTERNAL 
 \\ CUTANEOUS 
 
 OBTURATOR 
 Lr.MIto- SACRAL CORD 
 
 -, FIRST 8 A CRA L 
 NER VE 
 
 FIFTH SACRAL 
 NER VE 
 
 VISCERAL BRANCHES 
 Si'inlii- itrlery 
 
 Small sacro-sciatic 
 
 ligament 
 PUDIC NER VE 
 
 NERVE TO 
 OBTURA TOR 
 INTERNUS 
 
 PER FORA TING 
 CUTANEOUS OF 
 SECOND A ND 
 THIRD SACRAL 
 NERVES 
 
 FIG. 194. A DISSECTION OF THE LUMBAR AND SACRAL PLEXUSES, FROM BEHIND. 
 (The anterior crural nerve is placed between the external cutaneous and obturator nerves.) 
 
 and with a very delicate touch, to avoid injuring the small branches given off to 
 the sympathetic pelvic part of the gangliated cord. After this is done, all the 
 fat must be dissolved by ether, benzene, or gasoline. (2) Now dissect in the 
 direction of the branches given off, and find the following : 
 
 BRANCHES OF THE SACRAL PLEXUS. 
 i. Tlic lumbo-sacral cord is the communication between the sacral and lum- 
 
 bar plexuses. 
 19 
 
 It is formed by the fifth lumbar and part of the fourth lumbar 
 
282 PRACTICAL ANATOMY. 
 
 anterior primary divisions. This must now be located on the ala of the sacrum 
 as it passes down into the pelvis, and its union with the first, second, and third 
 sacral nerves carefully shown. 
 
 2. Muscular brandies to the pyriformis, the quadratus femoris, the gemellus 
 superior, the gemellus inferior, and the obturator interims muscles. Notice ! 
 You will find the branch to the obturator internus, leaving the pelvis by the 
 greater and reentering by the lesser sacro-sciatic foramen. When you dissect 
 the structures in the lesser sacro-sciatic foramen, you will find this nerve with the 
 internal pudic structures. The nerve to the quadratus femoris and gemellus 
 inferior leaves the pelvis by the greater sacro-sciatic foramen, and supplies a 
 branch to the hip-joint as well. 
 
 . You will trace the superior gluteai nerve through the greater sacro-sciatic 
 foramen, above the pyriformis muscle, to the gluteus medius, gluteus minimus, 
 and tensor vaginae femoris. The skin covering these muscles is not sup- 
 plied by this nerve -trunk apparently, but by the ilio-hypogastric and lumbar 
 cutaneous branches from posterior primary divisions. Now, let me impress 
 on the student this fact : A nerve-trunk supplying a muscle must supply the 
 skin covering the muscle, or the serous membrane under the muscle, it 
 any serous membrane be present, and the joint moved by the muscle. The 
 skin branches, in the majority of cases, are given off directly from the nerve- 
 trunk, and are easily found. In a minority of cases, however, the skin branch is 
 not given off directly, but comes from apparently another source ; to such cases as 
 these I see no impropriety in applying the terms divorced, dismembered, or erratic. 
 Confirmatory instances of divorced skin branches are to be found in the small 
 sciatic, the dismembered cutaneous branch of the great sciatic, supplying the 
 skin covering the muscles supplied with motion by the great sciatic nerve ; in the 
 external cutaneous nerve, on the outer part of the thigh, this nerve being divorced 
 from its parent stem, the anterior crural ; in the long pudendal nerve, or nerve of 
 Soemmering, the dismembered branch of the internal pudic nerve, following, in- 
 deed, a most erratic course, ensconced in the sheath of the small sciatic nerve ; 
 in the descendens hypoglossi, a divorced branch of the cervical plexus. In view 
 of the occurrence of anomalies, then, you are to ask yourselves, when dissecting 
 mixed nerves : Have I found (i) muscular branches, (2) cutaneous branches, (3) 
 articular branches ? and (4) are the cutaneous branches direct descendants of tin 
 nerve -trunk, or are they divorced therefrom ? 
 
 3. The inferior gluten! nerve leaves the pelvis by the greater sacro-sciati( 
 foramen below the pyriformis muscle and supplies the gluteus maximus. 
 
 4. The perforating cutaneous nerve will be found when you dissect the 
 region, coming through the greater sacro-sciatic ligament to supply the skin ii 
 this region. 
 
 5. The internal pudic nerve is remarkable for the great number of important 
 areas in which it and its branches are found. It leaves the pelvis by the greater 
 sacro-sciatic foramen below the pyriformis muscle, crosses the ischial spine, reen- 
 ters the pelvis by the lesser sacro-sciatic foramen, here enters Alcock's canal, 
 in the outer \vall of the ischio-rectal fossa, then pierces the triangular ligament, 
 passes through the deep perineal space, again pierces the triangular ligament, 
 passes through the suspensory ligament of the penis to gain the dorsum of this 
 organ. In its course 'it throws off the following branches : As the nerve is 
 entering the canal Alcock's it gives off the inferior lieinorrlioulal and tin 
 prrincal branches. These pass through the fat-bearing ischio-rectal fossa. Th< 
 inferior hemorrhoidal nerve is distributed to the external sphincter ani mnsclt 
 and the skin covering the same. The perineal branch is distributed to the accele- 
 rator tirin;e, transvcrsus perin.ei. erector penis, levator ani, compressor urethra, 
 and to the skin covering the scrotum and petineum. The internal pudic nerve 
 
THE PELVIS. 283 
 
 now continues its course in Alcock's canal, and through the deep triangular peri- 
 neal space, under the name of dorsal nerve of the penis, to which, with the sym- 
 pathetic from the pelvic plexus, it is distributed. 
 
 6. The small sciatic leaves the pelvis by the greater sacro-sciatic foramen 
 below the pyriformis, and breaks up into four principal cutaneous branches 
 ascending, descending, external, and internal. The largest of the internal branches 
 crosses the tuberosity of the ischium, and is distributed to the labia majora under 
 the name of inferior pudendal, or nerve of Soemmering. 
 
 7. The great sciatic nerve takes its name at the lower border of the greater 
 sacro-sciatic foramen, through which you see it leaving the pelvis below the pyri- 
 formis muscle. Examine closely and you can see some very small branches. 
 These are articular to the hip-joint. Lower down are given off muscular branches 
 to the biceps semitendinosus, semimembranosus, and adductor magnus muscles. 
 As a rule, the nerve divides six inches above the knee into the internal and 
 external popliteal nerves. 
 
 Branches of the Internal Popliteal Nerve of Great Sciatic : 
 
 1. The communicans tibialis to the communicans fibularis, a branch of the 
 external popliteal to form by this union the short saphenous nerve. This nerve 
 supplies the skin over the superficial group of muscles of the leg. 
 
 2. Articular- branches to the knee, with the articular arteries, superior and 
 inferior internal, and the azygos. 
 
 3. Muscular branches to the gastrocnemius, soleus, plantaris, and popliteus. 
 
 4. Posterior tibial, which gives off an articular branch to the ankle ; a plantar 
 cutaneous branch to the heel and sole of foot on the inner side ; muscular 
 branches to the flexor longus digitorum, tibialis posticus, flexor longus hallucis ; 
 a communicating branch to the soleus muscle. 
 
 5. The internal plantar, which gives off articular branches to the tarsus and 
 metatarsus, digital cutaneous branches to the four lesser toes, muscular branches 
 to the abductor hallucis, flexor brevis digitorum, flexor brevis hallucis, and the 
 two tibial lumbricales. 
 
 6. Extei'nal plantar, that supplies one and one-half toes cutaneously ; mus- 
 cular branches to flexor accessorius, abductor minimi digiti, the two outer lumbri- 
 cales, the adductor hallucis obliquus, the adductor hallucis transversus, the 
 flexor brevis minimi digiti, and all the interossei muscles. 
 
 Branches of the External Popliteal of Great Sciatic : 
 
 1. The communicans fibularis to the communicans tibialis to form the short 
 saphenous nerve. 
 
 2. Three articular branches to the knee, proceeding with the superior and 
 inferior external articular arteries and the azygos. 
 
 3. Cutaneous brandies to the skin covering the peronei muscles, being given 
 off with the communicans fibularis. 
 
 4. The anterior tibial nerve, which gives off an articular branch to the ankle, 
 to the metatarso-phalangeal joints of all the toes. Muscular brandies to the 
 tibialis anticus, extensor proprius hallucis, extensor longus digitorum, extensor 
 brevis digitorum, and a muscular branch to the first interosseous muscle. 
 
 5. The musculo-cutancoiis, which gives off its muscular branches to the 
 peroneus longus and peroneus brevis muscles. Cutaneous branches, internal 
 and external, to the dorsum of the foot, communicating with the internal and 
 external saphenous nerves. 
 
 1 . Where is the lumbar plexus located f 
 
 It is behind the peritoneum in the deep substance of the psoas magnus muscle. 
 
 2. How is tlie lumbar plexus formed / 
 
 By the union of the anterior primary divisions of the first, second, third, and 
 a part of the fourth lumbar nerves, and the dorsi-lumbar cord. 
 
284 PRACTICAL ANATOMY. 
 
 3. \Vitli what docs tlic lumbar plexus communicate .' 
 
 (l) With the twelftli thoracic nerve, by a branch named the dor.si lumbar ; (2) 
 with the sacral plexus, by a branch called the lumbo-sacral cord ; (3) with the 
 lumbar part of the gangliated cord, by branches called rami communicantes. 
 
 4. Describe the sympathetic connection, and tell Juw to conduct a dissection of the 
 same in tins region. 
 
 The lumbar part of the gangliated cord is quite easily found ; the communi- 
 cations with the anterior primary divisions of the lumbar nerves are not difficult 
 to trace out. The double chain of the sympathetic cord consists of four ganglia 
 on each side ; these ganglia are : (l) Right, which lie behind the ascending vena 
 cava ; (2) left, which lie behind and slightly external to the aorta. Find the cord 
 communicating above with the thoracic, and below with the pelvic portion, by 
 continuity. The rami communicantes are quite long in this region ; as a rule, 
 they are two in number, and they accompany the lumbar arteries. The lumbar 
 arteries, then, are your guide in tracing the relation between the lumbar plexus of 
 somatic nerves, and the lumbar part of the sympathetic gangliated cord. 
 
 5. Name the branches of the lumbar plexus. 
 
 The ilio-hypogastric, ilio-inguinal, genito-crural, external cutaneous, anterior 
 crural, obturator, accessory obturator, muscular branches to the psoas magnus 
 and quadratus lumborum, and the lumbar element of the lumbo-sacral cord. 
 
 6. Give formation and location of the lumbo-sacral cord. 
 
 It is formed by the union of the fifth lumbar nerve and a part of the fourth. 
 In practical anatomy you find it buried, in a considerable quantity of fatty con- 
 nective tissue behind the peritoneum, on the ala of the sacrum. This cord gives 
 origin to the superior gluteal nerve, described previously. 
 
 7. Describe the genito-cniral nerve, and give its practical importance in 
 diagnosis. 
 
 The nerve arises from the first and second lumbar nerves. It lies on the psoas 
 magnus muscle in the lower part of its course. It divides into: (i) A genital 
 branch, which follows the spermatic vessels and supplies the cremaster muscle 
 with motion. In practical anatomy you find this branch behind the spermatic cord. 
 (2) A cutaneous branch, the crural, which is distributed to the skin of the upper 
 inner part of the thigh. The cremasteric reflex depends on this nerve. Irritate 
 the skin of the thigh corresponding to the sensory distribution of this, the genito- 
 crural nerve, and the testicle of the corresponding side will be elevated by the 
 contraction of the cremaster muscle. In diagnosis, the movement of the testicle 
 thus produced argues in favor of the integrity of the spinal cord between the first 
 and second lumbar nerves. In the female this nerve is rudimentary, and, there 
 being no cremaster in this sex, the genital branch of the nerve is distributed tc 
 the round ligament of the uterus ; the crural branch is distributed as in the male. 
 The reflex phenomena in the female are recorded as a twitching of the external 
 oblique ; still, I think careful observation would prove such record erroneous. Th< 
 twitching must be in the round ligament of the uterus, since this is the homo- 
 logue of the spermatic cord. 
 
 8. Describe a patellar reflex circuit and give its importance in diagnosis. 
 
 The anterior crural nerve is concerned in this reflex. Sensory branches from 
 this nerve, distributed over the insertion of the quadriceps, forming the plexus 
 patella-, convey sensation to a transfer centre ; and motor branches from the 
 anterior crural induce contraction of the extensor group of muscles on the fronl 
 of the thigh. flu's reflex movement is normal in health. It is absent in loco- 
 motor ataxia and in the case of lesions and diseases affecting the anterior gray 
 cornua of the spinal cord. It is increased after epileptic sei/ures, in spinal irrit- 
 ability, tumors of the brain and disease-^ <>f the lateral tracts of the cord, and in 
 lateral and c vivbro-spinal sclerosis. 
 
 
THJ'. PELVIS. 285 
 
 9. Explain tJic tecJinicjue of obtaining knee-jerk, or patcllar reflex movement. 
 
 (i) Place the patient in the sitting posture on the table, with his legs hanging 
 at right angles to the thighs ; (2) blindfold the patient, and do not acquaint him 
 with the procedure ; otherwise, through nerve-influence from the obturator to the 
 sartorious muscle, phenomena of a voluntary nature on the part of the patient 
 might be observed which would cloud your diagnosis ; (3) tap the ligamentum 
 patellae with a ferrule, or, better still, gently prick the skin over the same with a 
 sharp instrument. Students should be encouraged to practice obtaining these 
 reflexes on one another. 
 
 DIAPHRAGM. (Fie. 195.) 
 
 Function. Partition between thorax and abdomen. 
 Superior Serous Relations. Pericardium and pleurae. 
 Inferior Serous Relations. The diaphragmatic peritoneum. 
 Structure. A musculo-membranous sheet. 
 Apertures. CEsophageal, aortic, and caval. 
 Ligamentum arcuatum inter tiiun, part of iliac fascia. 
 Ligamentum arcuatum cxternum, part of lumbar fascia. 
 Central tendon forms the summit of the dome. 
 CEsophageal opening transmits oesophagus and vagus nerves. 
 Aortic opening transmits aorta and thoracic duct. 
 Caval opening transmits the ascending vena cava. 
 Physiological Action. Deepens the chest. 
 Nerve-supply. The two phrenics and the sympathetic. 
 Source of Sympathetic Nerve-supply. Solar plexus. 
 Blood-supply. The phrenic arteries. 
 
 Source of Plirenic Arteries. Aorta, renals, and intercostals. 
 Hoiv many origins lias the diaphragm ? 
 
 1. Anterior or Sternal Portion. The lower border and back of the ensiform 
 cartilage and the adjacent part of the back of the anterior aponeurosis of the 
 transversalis abdominis. 
 
 2. Lateral or Costal Portion. The lower border and inner surface of the 
 cartilages of the six lower ribs, and sometimes also from the adjacent part ot 
 the ribs. 
 
 3. Posterior or Vertebral Portion. (i) The ligamentum arcuatum externum, a 
 fibrous thickening of the anterior layer of the lumbar fascia, which stretches 
 from the tip of the transverse process of the second lumbar vertebra to the tip 
 of the last rib ; (2) the ligamentum arcuatum internum a fibrous thickening of 
 the iliac fascia, which arches over the upper part of the psoas from the sick- of 
 the body of the second lumbar vertebra to the tip of its transverse process ; (3) 
 the cms of the diaphragm a strong vertical band, fleshy externally, tendinous 
 internally, arising on the right side from the front of the bodies of the first to 
 the third or fourth lumbar vertebra;:, from the intervening vertebral discs, and 
 the anterior common ligament ; on the left side, from the bodies of the first to 
 the second or third vertebrae only, as well as the discs and anterior common 
 ligament. 
 
 Insertion. The front, sides, and back of the central tendon. 
 
 The crura are perforated, and transmit structures as follows : The right, the 
 sympathetic and the splanchnics of the right side; the left, the splanchnics of 
 the left side and the vena azygos minor. 
 
286 
 
 PRACTICAL ANATOMY. 
 
 Visceral Relations. On careful dissection you will see the diaphragm bears 
 very important relations to the following structures : (i) As previously indicated, 
 the superior surface of the diaphragm is occupied by the three serous membranes. 
 The pulmonary surface of the diaphragm corresponds to the base of the lung. 
 The cardiac surface corresponds to the base of the pericardium. (2) The liver, 
 stomach, spleen, kidneys, and suprarenal capsules are in relation with its under 
 surface. (3) The aorta, oesophagus, ascending vena cava, the vena azvgos minor, 
 the pucumogastric nerves, the splancJmics, the sympathetic all pass through the 
 diaphragm. (4) Posteriorly, the diaphragm arches over the psoas magnus and 
 the quadratus lumborum. A fibrous arch, formed by the iliac fascia, arches over 
 the psoas ; one formed by the anterior layer of the lumbar fascia arches over the 
 quadratus lumborum muscle. Consult carefully figure 195. Lastly, remove 
 the peritoneal covering of the diaphragm, and see the beautiful manner in which 
 the fibers from the three different sources of origin approach for insertion the 
 
 Sternal origin 
 
 Opening for vena 
 cava inferior 
 
 Right division of 
 tendon 
 
 Aorta - -i 
 
 Bight crus 
 Psoas parvus 
 
 Psoas 
 
 Transversalis 
 abdominia 
 
 Middle division 
 of tendon 
 
 (Esophagus 
 
 Left division of 
 tendon 
 
 '.- Costal origin 
 
 Ligamentum 
 
 arouatum 
 
 internum 
 Left crus 
 Ligamentum 
 
 arcuatum 
 
 externum 
 Transverse 
 
 process of 
 
 second lumbar 
 
 vertebra 
 Fourth lumbar 
 vertebra 
 
 
 FIG. 195. DIAPHRAGM. 
 
 central tendon. The central tendon corresponds to the base of the pericardium ; 
 the fibrous part of the pericardium is the downward prolongation and expansioi 
 of the third layer of the deep cervical fascia, having firm bony attachments to 
 the base of the skull ; hence, in deep inspiration it is not the central tendon that 
 becomes depressed, but the muscular part of tlie diapliragm. 
 
 I Dissection of Av/> Muscles and otlicr Structures of tlic Pelvis. (i) The quad- 
 ratus lumborum ; (2) psoas parvus ; (3) psoas magnus ; (4) iliacus ; (5) crura o 
 diaphragm ; (6) anterior common ligament of vertebral column ; (7) obturator 
 interims ; (8) obturator extern us ; (9) obturator membrane; (10) pyriformis 
 (i i) coccygeus ; (12) levator ani ; (13) white line of the obturator fascia. 
 
 
THE PELVIS. 
 
 287 
 
 Locate on your cadaver: (i) The iliac fossa; (2) the auricular surface of 
 the ilium ; (3) the tuberosity of the ilium ; (4) the tuberosity of the ischium ; (5) 
 the spine of the ischium ; (6) the spine of the pubes ; (7) the ilio-pubal ridge ; 
 (8) the ilio-pectineal line ; (9) the anterior and posterior surfaces of the pubes ; 
 (10) the ischio-pubic ramus ; (11) the thyroid or obturator foramen; (12) the 
 symphysis pubis ; (13) the anterior superior and anterior inferior iliac spines; 
 
 Quadratus lumborum 
 I 
 
 Erector spinse 
 
 TUBEROSITY 
 
 AURICULAR SURFACE 
 
 POST. INF. SPINE OF 
 ILIUM 
 
 Transversalis and the iliac 
 fascia 
 
 GROOVE FOR PUDIC 
 
 VESSELS AND 
 
 NERVE 
 
 Qt. sacro-sciatic 
 ligament 
 
 x^ 
 
 JUNCTION OF PUBES Crus penis and Compressor Subpubie 
 
 AND ISCHIUM Erector penis urethras ligament 
 
 FIG. 196. THE LEFT HIP-BONE. (Internal surface.) 
 
 ANT. SUP. SPINE OF 
 ILIUM 
 
 ANT. INF. SPINE OF ILIUM 
 
 Fsoas minor 
 
 ILIO-PUBAL RIDGE 
 
 GROOVE FOR OBTURATOR 
 NERVE AND VESSELS 
 
 .SYMPHYSIAL SURFACE 
 Levator ani 
 
 (14) the posterior superior and posterior inferior iliac spines ; (15) the greater 
 and lesser sacro-sciatic foramina; (16) the greater and lesser sacro-sciatic liga- 
 ments ; (17) the obturator groove. Locate the above points on the cadaver, 
 and in the progress of your dissection find and dissect the soft structures 
 attached to them or in any way bearing important relations thereto. Study 
 thoroughly the os innominatum. 
 
 Dissection. Quadratus Lumborum. Find the origin on the ilio-lumbar 
 
288 
 
 PRACTICAL ANATOMY. 
 
 ligament and the iliac crest for two inches. Trace the muscle to its insertion 
 into the lower border of the twelfth rib and into the transverse processes of the 
 four upper lumbar vertebrae. Now place the kidney in its original position on 
 this muscle. This muscle lies in front of the erector spinse muscle. In fact, 
 these two muscles form a guide to operations on the kidney. See whether you 
 can demonstrate on your work these structures, in the following relation from 
 behind forward : (i) The quadratns linnbontin ; (2) the lumbar fascia; (3) the 
 last thoracic nerve, the ilio-liypogastric and ilio-ingnhial nerves ; (4) the fatty 
 capsule of the kidney ; (5) the kidney. In operations on the kidney from behind, 
 
 Quadratus lumborum 
 
 Faoaa parvus 
 
 Fsoaa magnus 
 
 Iliac us 
 
 Intertransversalis 
 anterior 
 
 Quadratus lumborum 
 
 IK;. 197. PSOAS, II.IACUS, AND QUADRATUS LI;.MI;<>KI M. 
 
 you would find the above relations. Study the above relations until you ha> 
 perfect picture of all these Structures ill your mind. The lower end of the kidney 
 is about one and one-half inches above the iliac crest. 
 
 The psoas magnus muscle in its relation to vessels and nerves has been 
 previously described. The muse -le has a strong synergist in the iliacus. The-e 
 two are sometimes spoken of as one muscle, with two heads or parts the i/io- 
 />so<ts. The two muscles are inserted into the lesser trochanter of the femur. 
 My this action, when the thigh is the fixed point, they draw the pelvis forward, 
 rotating the same on the heads of the femur. They thus antagoni/c the glutcus 
 maximus. The psoas magnus <7/-/.sv.v from the sides of the bodies of tin- last thor- 
 
THE PELVIS. 
 
 289 
 
 acic and all the lumbar vertebrae, and from their intercentral cartilages ; from 
 the lower border of the transverse processes of the lumbar vertebras. The 
 nerve-supply is from the lumbar plexus. The nerve-supply of the iliacus is from 
 the anterior crural part of the lumbar plexus. 
 
 The Iliacus. Detach from its origin and turn it down to its insertion into 
 the lesser trochanter of the femur with the psoas magnus. This is a flexor of 
 the thigh on the abdomen. Its synergist is the psoas. It also pulls the body 
 forward, when the thigh is made the fixed point, antagonizing the gluteus maxi- 
 mus. Its nerve-supply is from the anterior crural of the lumbar plexus. 
 
 Origin. (i) The upper surface of the ala of the sacrum ; (2) the front of the 
 ilio-lumbar, lumbo-sacral, and anterior sacro-iliac ligaments ; (3) the upper and 
 outer half of the venter of the ilium ; (4) the origin of the upper tendon of the 
 rectus femoris and the ilio-femoral ligament near the anterior inferior spine of 
 the ilium. 
 
 The Psoas Parvus. Usually absent. Inserted into the ilio-pectineal line. 
 Origin : Side of twelfth thoracic and first lumbar and disc of cartilage between 
 
 ... Transversalis 
 
 -! Internal oblique 
 
 " External oblique 
 
 Sacro-lumbalis 
 
 LatiBSimus dorsi 
 
 Quadratus lumborum 
 
 FlG. 1C 
 
 Longissiinus dorsi 
 Psoas magnus 
 
 . ARRANGEMENTS OF LUMBAR APONEUROSIS AT LEVEL OF THIRD LUMBAR VERTEBRA. 
 
 the two. Synergistic to psoas magnus. Its nerve-supply is from the first nerve 
 of the lumbar plexus. 
 
 The obturator internus may now be removed from its origin. (Fig. 196.) 
 Trace the same through the lesser sacro-sciatic foramen. Study the origin from 
 the marein of the obturator foramen, the obturator membrane, and the inner 
 
 o 
 
 surface of the body of the ischium. Its nerve-supply is from the first and second 
 nerves of the sacral plexus ; it passes through the lesser sacro-sciatic foramen. 
 
 Obturator Externus. Detach the muscle from the bony margin of the 
 obturator foramen ; from the obturator membrane. It^s inserted into the digital 
 or trochanteric fossa. It is supplied by the obturator nerve. Now you can see 
 and study the obturator membrane. See the obturator nerve coming through a 
 notch on under surface of the horizontal ramus of the os pubis. 
 
 Locate on tlie sacrum (Fig. 199) : (i) The bodies ; (2) the anterior sacral fora- 
 mina ; (3) the transverse lines ; (4) the ala or wing ; (5) the sacro-coccygeal artic- 
 ulation ; (6) the origin of the pyriformis ; (7) the grooves leading to the foramina. 
 
 The pyriformis arises from the anterior surface of the sacrum by three 
 
290 
 
 PRACTICAL ANATOMY. 
 
 digitations. (Fig. 199.) It leaves the pelvis by the greater sacro-sciatic fora- 
 men, dividing this into an upper and a lower compartment, and is inserted into 
 
 Fyriformi* 
 
 TUBEROSITY 
 
 CoocygeuB 
 
 Coccygeus 
 
 Levator Ani 
 
 FIG. 199. THE SACRUM AND G>< c Y\. (Anterior view. \ 
 
 SACi;rs: 
 
 Pyriformis 
 
 COCCYX 
 
 Levator ani (divided 
 below the ' white line ') 
 
 Space for obturator 
 internus 
 
 RECTUM 
 PROSTATE 
 
 8YMPHYSIS 
 
 agt, for gh 
 vessels and mrrc 
 
 Pyriformis 
 
 1'iixfiti/i' fur xcitilic 
 mil! /mdif vessel* 
 nni! nerve 
 
 ISCHIAL SPINE 
 
 Coecygeus 
 Cellular interval 
 Levator ani 
 
 Capsule of prostate, 
 and pubo-prostatio 
 ligaments 
 
 1 ic. zoo. MUSCLES OF THE FLOOR OK TIIK PELVIS. 
 
 the upper border of the greater trocliantcr. It is an external rotator of th< 
 thigh. Its iicn-c-sitfiply is from the sacral plexus. 
 
 The COCCygeus extends from the spine of the ischium to the anterior snrfaa 
 
THE PELVIS. 
 
 291 
 
 and side of the coccyx. It separates two intermuscular cellular spaces (i) one 
 between itself and the pyriformis, and (2) one between itself and the levator ani. 
 (Figs. 199 and 200.) Its nerve- supply comes from the coccygeal plexus. 
 
 The levator ani (Fig. 200) arises from the back of the pubic bone and from 
 the inner surface of the ischial spine. Between these two points it arises from 
 the white line. The muscle has a triple insertion : (i) Into the tip of the coccyx ; 
 (2) into the central point of the perineum ; (3) into the rectum. In the female 
 the anterior fibres are inserted into the side of the vagina. Function : It draws 
 the coccyx forward, elevates the floor of the pelvis, and aids in compressing the 
 pelvic viscera. 
 
 The pelvic white line is formed by a delamination of the obturator fascia. 
 It extends from the spine of the ischium to the pubic bone. (Fig. 200.) It 
 gives partial origin to the levator ani muscle. 
 
 FEMALE GENERATIVE ORGANS. 
 
 Now thoroughly cleanse the pelvis and study the internal organs of genera- 
 tion of the female as follows : 
 
 1 . Observe in front of the uterus, the bladder, partially covered by perito- 
 neum. In front of the bladder you will see a cellular space called Retzius' 
 space. 
 
 2. Pull the uterus to one side and study the relation of the following struc- 
 
 AMPUUA OF FALLOPIAN TUBE 
 
 FALLOPIAN TUBE 
 
 EXTERNAL ANGLE OF UTERUS 
 
 FIMBRIATED EXTREMITY OF TUBE Hound ligament 
 
 FIMBRIA OVARIOA Ligament of ovary 
 
 Anterior peritoneal lamina 
 
 FIG. 201. THE BROAD LIGAMENT AND ITS CONTENTS, SEKN KROM THE FRONT. (After Sappey). 
 
 tures : (i) The round ligament of the uterus; (2) the ligament of tJic ovary; 
 (3) the Fallopian tube, or oviduct. 
 
 As you pull the uterus to the opposite side, you will notice these three 
 structures dispersing to different parts from the angle of the uterus. Trace 
 them out, remembering they are all between the two layers of the broad liga- 
 ment (Fig. 201), as follows : (i) The round ligament to the internal abdominal 
 ring, on the outer side of the deep epigastric artery, down through the inguinal 
 
292 
 
 PR A CTICAL ANA TOM ) . 
 
 canal, out through the external abdominal ring, to the labia majora ; (2) the ovarian 
 ligament terminates in the capsule of the inner end of the ovary ; (3) trace the 
 oviduct /'. e., the Fallopian tube to the outer end of the capsule of the ovary, 
 to which it is attached by one of the fimbriae, called the ovarian fimbria. 
 
 3. Locate tJie ureter as it passes down over the brim of the pelvis ; trace it 
 
 FIG. 202. REPRESENTING SCHEMATICALLY THE RELATION OF THE URETER TO THK BROAD 
 
 LIGAMENT OF THE UTERUS. 
 
 A. Peritoneum. B. Peritoneum in relation to bladder. C. Peritoneum pushed ahead of the uterus 
 called broad ligament. D. Space between the two layers of broad ligament containing uterus and 
 adnexa. E. The ureter. F. Uterine and ovarian vessels. 
 
 carefully as it approaches the posterior surface of the broad ligament. (Fig. 202.) 
 Now, as it passes under, cut a hole in the posterior surface of the broad ligament 
 and follow it across the base and to the bladder. Notice, too, that as you take 
 hold of the broad ligament and lift it up, the ureter remains in place. There 
 would, seem to be little danger of including this structure in the ligature in opera- 
 
 UTERINE WALL 
 CAVITY OF BODY 
 
 CAVITY OF CERVIX WITH ARBOR VITA - 
 
 IMC. 203. FKONTU, SKCTION <>i riu YIUCIN UTKRUS. (After Sappey.) 
 
 tions on the ovary and tube. As the ureter lies on the levntor ani, there would 
 be more danger of wounding it in operations on the ischio-rectal fossa than in 
 the operation before mentioned. The ureter remains firmly embedded in the 
 deep layer of subperitoncal connective tissue, anil can not be raised by any 
 ordinary amount of traction exerted on the ovary, tube, and broad ligament. 
 
THE PELVIS. 
 
 2 93 
 
 Cervical branch 
 
 Coronal artery 
 
 Branch. Brandies Branch 
 
 I'terine toroti/nl to to EXTREMITY OF 
 
 branch ligament isthmus ampulla FALLOPIAN TUBE 
 
 \ 
 
 Ovarian branches 
 
 Uterine artery 
 Internal iliac artery 
 
 Vaginal arteries 
 
 Azygos artery of vagina 
 FIG. 204. SCHEME OF THE OVARIAN AND UTERINE AND VAGINAL ARTERIES. 
 
 POSTERIOR SURFACE OF BODY OF UTERUS 
 
 IT tero -ovarian ligament 
 OVARY 
 
 FALLOPIAN TUBE 
 
 Broad ligament 
 
 FIMBRIATEO EXTREMITY 
 
 OF TUBE 
 FIMBRIA OVARICA 
 
 Lower 
 
 part of broad ligament 
 OS UTERI 
 
 OS EXTERNUM 
 
 VAGINAL WALL, DIVIDED AND REFLECTED 
 
 VAGINA, ANTERIOR WALL 
 
 FIG. 205. THE FEMALE ORGANS OF GENERATION. (Modified froru Sappey. 
 (Vagina divided and laid open behind.) 
 
294 
 
 PRACTICAL ANATOMY. 
 
 The Ovarian Artery and the Sympathetic Nerve. This artery you will 
 see shining through the peritoneum, passing behind the ureter, opposite the 
 bifurcation of the aorta. You will remember its origin from the aorta, below 
 the renal, and its homologue, the spermatic. Trace it down in this manner : Lift 
 the peritoneum up, over the artery, and cut the same with the scissors. Make 
 every effort not to disturb the artery in its bed. Trace the artery now to the 
 lateral space, between the two folds of broad ligament (Fig. 202), to its distribu- 
 tion and anastomosis, as shown in figure 204. You will find the uterine artery 
 embedded in the side of the uterus, between the two folds of the broad ligament. 
 Find the artery, and trace it out to its origin from the internal iliac artery. (Fig. 
 204.) You will find an abundant supply of sympathetic nerves forming the uterine 
 plexus. Figure 203 gives a frontal section of the uterus, which you may now 
 imitate. In the angle of the uterus find the opening for the Fallopian tube. 
 Locate the os internum and externum. Figure 206 is a sagittal section. Cut 
 through the vagina and study the utero-vaginal junction. 
 
 Remember the analysis of the pelvic plexus. Formed : (i) by prolongation 
 of the hypogastric plexus ; (2) by branches from the second, third, and fourth 
 
 FUNDUS 
 
 08 INTERNUM -V- 
 
 CAVITY OF CERVIX 
 
 POSTERIOR FORNIX 
 POSTERIOR LIP 
 
 CAVITY OF BODY 
 
 REFLEXION OF PERITONEUM 
 
 ANTERIOR LIP 
 ANTERIOR FORNIX 
 
 OS EXTERNUM 
 
 FIG. 206. SAGITTAL SECTION OF THE VIRGIN Unau's. (After Sappey.) 
 
 sacral nerves ; (3) by branches from the two upper sacral ganglia. Located : By 
 the side of the rectum, vagina, and uterus in the female. Distribution : To all the 
 viscera in the pelvis. The nerves accompany the branches of the internal iliac 
 artery. The nerves proceed from a plexus on the artery ; the plexus proceeds 
 from a ganglion ; the ganglion is supported by the pelvic plexus ; the pelvic plexus 
 is in communication with the hypogastric plexus through a prolongation of this 
 latter. 
 
 I . \aine (lie ligaments of tlie uterus you hare tints far found, ami explain 
 tlteir derivation. 
 
 (i) The round ligament; (2) one in front, called the anterior or vesico- 
 uterine; (3) one posterior, the recto-uterine; (4) two sacro-uterine ; (5) two 
 broad ligaments. The round ligament that in your dissection you tr.uvd 
 through the inguinal canal, is lost in tin- lahia majora ; it is homologous to tlu- 
 spermatic cord. It is composed of fibrous and muscular tissue from the uterus. 
 Thecord N attended 1>\ a hood of peritoneum called the canal of Nuck. To SC 
 
THE PELVIS. 295 
 
 this canal before it becomes obliterated, you must examine female foetuses. The 
 other uterine ligaments are of peritoneal origin, and can and must be demon- 
 strated on your work. 
 
 2. From u>/iat source does the n terns receive its blood / 
 
 Through the uterine branch of the internal iliac artery. It anastomoses 
 above with the ovarian and below with the vaginal arteries. It is surrounded 
 by the uterine plexus of nerves, from the pelvic plexus. (Fig. 204.) 
 
 3. Explai)i the rationale of contraction of adhesions in retroflcxions. 
 
 In the dissection of the peritoneum it was shown that an organ previously 
 invested by peritoneum, may lose its peritoneum, in parte or in toto, by loss of 
 the blood-supply at a given point, by pressure. .(Fig. 170.) The uterus bears the 
 same relation to its investing peritoneum that the colon does to its own. Things 
 equal to the same thing are equal to each other ; the two results are identically 
 the same. The colon, by loss of its specific epithelial element, becomes physio- 
 logically adherent to the parietes, because this adhesion will cause no ulterior 
 hindrance to the function of the colon. The uterus, however, contracts patho- 
 logical adhesions, because the uterus can not, in the position these adhesions 
 entail, discharge its function physiologically. 
 
 4. Does the uterus undergo important structural changes / 
 
 Anatomical structure is always the correlative of function. Not only the 
 uterus, but all its appendages, obey this law of philosophy correlation ot 
 structure and function. In the pre-puberty state, the female genitalia are pro- 
 ducts of growth, not of development ; in the post-puberty state they are the pro- 
 ducts of both growth and development. During menstruation and pregnancy, 
 the uterus and its appendages become relatively changed in size according to 
 function. At the menopause, with cessation of functional activity, these parts 
 become metamorphosed, in a retrograde manner. 
 
 5. Explain the anatomical factors in the production of ovarian, uterine, rectal, 
 and uretliro-vcsical reflexes in short, of pelvic reflexes in general and particular. 
 
 This belongs to physiology, to which chair I refer a detailed answer ; but 
 in order to make you familiar with the anatomical elements involved in reflex 
 phenomena, I know you will pardon just enough physiological digression to 
 keep up an interest in the anatomical regions involved. 
 
 Reflexes are of two general kinds : (i) simple ; (2) complex. The simplicity 
 of the one depends on the positive conductivity of somatic nerves and the sim- 
 plicity of the factors involved. 
 
 The complexity "of the other depends on the negative conductivity of sympa- 
 thetic nerves and the complexity of the factors involved. 
 
 The factors involved are: (i) A nerve-center capable of receiving sensory 
 impressions from sentient areas, and capable of originating motor impulses ; 
 (2) connecting media between the center and the sentient area capable of trans- 
 mitting impressions of both sensation and motion. 
 
 Somatic nerves are those that supply the body-wall ; they are usually called 
 spinal and cranial. Those nerves are called sympathetic that are set aside 
 principally for the regulation and movement of the viscera. They are the visceral 
 branches of the spinal nerves. The former transmit pain and motion violently, 
 rapidly, positively ; the latter slowly, slight in degree, negatively, compared to 
 the same in somatic areas. (See page 264, et scq.} 
 
 Law of Projectiles. In addition to the central and peripheral factors, and 
 their motor and sensory communicating media, we must be mindful of the law of 
 
296 PRACTICAL A A' ATOMY. 
 
 projectiles. The nerves to and from the brain are media by which the impres- 
 sions travel. These impressions, then, and the nerves by which they travel, are 
 projectiles, and are amenable to the law of philosophy governing all projectiles : 
 (i) A projectile follows the line of least resistance ; (2) a projectile follows the 
 point of greatest traction ; (3) a projectile may follow the resultant of these two 
 /. e., the line of greatest traction and the point of least resistance. 
 
 Anatomical factors determining the above are simply the amount and kind 
 of nerve distribution at the locality whence the reflex proceeds. On this hypo- 
 thesis alone do we account for the reference of both pain and motion, in their 
 logical places, in simplex reflexes. In figure 1 87, a simple reflex, the logical 
 place for the pain is the conjunctiva; the logical place for the motion is in the 
 orbicularis palpebrarum. Here the influences, sensory and motor, follow the 
 greatest direct nerve distribution over cranial nerves having maximal ability 
 to transmit both sensation and motion. On this hypothesis do we account for 
 pain, the result of an irritant, for example, in the ovary, rectum, or uterus, not 
 in its logical place in the organ itself, but in its illogical place, far away in some 
 other part of the body, where both reflex pain and reflex motion may be the 
 symptoms. These are complex reflexes ; still, just as logical in every way and 
 just as amenable to the law of projectiles as simple reflexes. (Fig. 185.) 
 
 Pain is diagnostically one of the most important subjective symptoms. It is 
 reported peripherally. You must, then, have a thorough knowledge of the 
 cutaneous and membranous distribution of somatic nerves, since it is through 
 these nerves that pain from every organ in the body may make its demurrer. The 
 steps, then, anatomically, in tracing pain for diagnostic purposes are : 
 
 1 . What cutaneous or sensory nerves supply the part ? 
 
 2. Of what mixed nerve or plexus are they a part ? 
 
 3. Where do these mixed nerves leave the spinal canal ? 
 
 4. Do they correspond to the six upper intercostals ? 
 
 5. Do they correspond to the six lower intercostals ? 
 
 6. Do they correspond to the cervical plexus ? 
 
 7. Do they correspond to the brachial plexus ? 
 
 8. Do they correspond to the lumbar plexus? 
 
 9. Do they correspond to the sacral plexus ? 
 
 10. What territory of organs does the hypogastric plexus supply? 
 
 1 1. What territory does the solar plexus supply? 
 
 12. What territory does the cardiac plexus supply? 
 
 Any considerable pain, then, as previously stated, is reported by a somatic 
 nerve. If this somatic nerve is the innervation pure and simple of the painlul 
 part under consideration, then the pain is a simple direct pain. If, however, 
 as frequently happens, the somatic nerve is the medium through which vast 
 territories are made to suffer, while the exciting cause is in, some remote organ, 
 then this pain is a reflex pain. The somatic nerves may also produce reflex 
 muscular movements in the muscles corresponding to the region of the pain. 
 (See page 264.) 
 
 The student can not become too well grounded in the philosophical distribu- 
 tion of a mixed nerve : The nerve-trunk that supplies a group of muscles sup- 
 plies also the skin covering those muscles ; the articulation that these muscles 
 move ; the serous or synovial membrane in contact with which these muscles 
 may lie. The six upper intercostal nerves supply, then, not only intercostal 
 muscles, but the pleura as well ; the six lower supply not only the muscles of 
 the abdominal walls, but the peritoneum also. An organ, then, having a syi 
 pathetic nerve-supply, may manifest its pain either in skin, membranes, or artia 
 lations, and still not transcend the logic of the law of reflex phi-nomc-mi. 
 
 >matic 
 
THIGH AND LEG. 
 
 DISSECTION OF THE ANTERIOR REGIONS OF THE THIGH AND 
 LEG AND OF THE ADDUCTOR REGION OF THE THIGH. 
 
 The following review of the practical osteological points on the bones of 
 the lower extremity must be thoroughly mastered before the student can do 
 intelligent work on the cadaver. These points the student must study with the 
 bones in hand. Simply committing to memory a few pages of technical names, 
 with no knowledge of a practical application of the subject, would be as useless 
 here as in other departments of science. 
 
 The Tibia : 
 
 Name the bony points on tlie tibia of practical importance in dissection. 
 
 The internal tuberosity has one articular surface. 
 
 The external tuberosity has two articular surfaces. 
 
 The tubercle, into which the ligamentum patellae is inserted. 
 
 The crest, or anterior border, is subcutaneous. 
 
 The internal surface is three-fourths subcutaneous. 
 
 The upper two-thirds of the external surface is occupied by tibialis anticus. 
 
 The popliteal notch transmits the popliteal artery and vein. 
 
 The oblique line is on the posterior surface. 
 
 The femoral articular surfaces of the head. 
 
 The internal malleolus of the tibia. 
 
 The astragaloid articular surfaces of the tibia. 
 
 The posterior surface and its subdivisions. 
 
 The nutrient canal, directed from the knee. 
 
 How many articular surfaces has the tibia ? 
 
 It has six articular surfaces two femoral, two fibular, and two astragaloid. 
 The student must find these surfaces and name technically the articulations they 
 assist in forming. (See rule for forming compound words in introductory 
 chapter.) 
 
 What can yon say of the internal surface of the tibia / 
 
 It is subcutaneous in its lower three-fourths. (Fig. 207.) Its upper one-fourth 
 is occupied by the insertions of the semitendinosus and gracilis muscles, which 
 are inserted by tendons, and the sartorius, inserted by aponeurosis. 
 
 What important flexor muscle is inserted into the posterior part of tJic internal 
 tnherosity ? 
 
 The tendon of the semimembranosus muscle. It will be seen presently 
 that this muscle has also three aponeurotic insertions that have very important 
 relations and functions in the vicinity of the knee-joint. 
 
 Describe the posterior surface of the tibia. 
 
 It is divided by two lines an oblique and a vertical one into three sub- 
 divisions. (Fig. 208.) One of the three surfaces is occupied by the popliteus 
 muscle ; a second by the flexor longus digitorum ; a third by the tibialis 
 posticus. 
 
 20 297 
 
298 PRACTICAL ANATOMY. 
 
 Describe fully the oblique line of the tibia. (Fig. 208.) 
 
 It extends from the fibular articular surface to the middle one-third of the bone, 
 on the inner border. It may be considered as possessing three lips an upper, 
 a middle, and a lower. Into the upper is inserted the popliteal fascia ; from the 
 middle arises the tibial head of the soleus ; from the lower, the flexor longus 
 digitorum and tibialis posticus. 
 
 Describe the vertical line. 
 
 It extends in a curved line downward and outward to the middle one-third of 
 the outer or interosseous border of the tibia. It separates the surfaces occupied 
 by the tibialis posticus and flexor longus digitorum muscles. It also marks the 
 location of the nutrient foramen of the tibia, proceeding, according to rule, from 
 the knee. 
 
 Name the important parts of the internal mall coins of the tibia. 
 
 Posteriorly are two grooves for the tibialis posticus and flexor longus digi- 
 torum ; one surface articulates with the astragalus ; to the apex is attached the 
 internal lateral ligament of the ankle-joint. 
 
 The Fibula: 
 
 Name the points on the fibula of importance in practical anatomy. 
 
 The head, for insertion of the biceps tendon. 
 
 The styloid process of the head, for external lateral ligament. 
 
 The tibial articular surface. 
 
 The external malleolus of the fibula. 
 
 The anterior surface of the fibula. 
 
 The outer surface of the fibula. 
 
 The internal surface of the fibula. 
 
 The posterior surface of the fibula. 
 
 What is the importance of the anterior surface of the fibula / (Fig. 207.) 
 
 Its width is one-fourth of an inch. It gives origin to the extensor proprius or 
 extensor longus hallucis, the extensor longus digitorum, the peroneus tertius 
 i. e., all the muscles on the front of the leg, except the tibialis anticus. 
 
 What can you say about the external surface of the fibula f (Fig. 207.) 
 
 It gives origin to and is occupied by the peroneus longus and peroneus brevis 
 the former occupies the upper two-thirds ; the latter, the lower two-thirds. 
 
 What is the importance of the posterior surface of 'the fibula / 
 
 It gives origin in its upper one-third to the fibular head of the soleus ; in its 
 lower two-thirds to the flexor longus hallucis. (Fig. 208.) 
 
 Give the importance of the internal surface of tJic fibula. 
 
 It gives attachment to the tibialis posticus i. t\, to the fibular head of this 
 muscle. 
 
 / / 'hat can you say of the patella ? 
 
 It is the largest sesamoid bone in the body. It is developed in the common 
 tendon of insertion for the group of muscles that extend the leg on the thigh the 
 quadriceps extensor fcinoris. It has two articular surfaces, corresponding to tin- 
 trochlear articular surface of the femur. The ligamentum patellae is inserted into 
 the tubercle of the tibia. A pad of fat and a hursa intervene between the patella 
 and tibia, except at the insertion. 
 
 The Foot and Ankle : 
 
 \aine the osteological points of the foot and ankle of importance in dissection. 
 
 The posterior surface of the calcaneum. 
 
 The sustentaculum tali of the calcaneum. 
 
 The peroneal grooves of the calcaneum. 
 
 The inner and outer tuberositics of the calcaneum. 
 
 The cuboid surface of the calcaneum. 
 
 The astragaloid surface of the calcaneum. 
 
THIGH AND LEG. 299 
 
 The tuberosity of the scaphoid bone. 
 
 The cuneiform articular surfaces of the scaphoid. 
 
 The medio-tarsal articulation. 
 
 The base of the first metatarsal bone. 
 
 The base of the fifth metatarsal bone. 
 
 Wliat two tendons do yon expect to find on the outer surface of the calcanemn / 
 
 The tendons of the peroneus longus and brevis. They are separated by a little 
 spine of bone the peroneal intertendinous spine. Each tendon is in a separate 
 canal here, but higher up, behind the outer malleolus, they are in the same canal. 
 
 How woidd you describe the peronens innscle so as to give the bony parts of t/ie 
 limb due prominence ? 
 
 The peroneus longus arises from the outer surface of the fibula in its upper 
 two-thirds ; its tendon passes behind the external malleolus of the fibula, with the 
 tendon of the peroneus brevis ; it passes on the outer surface of the calcaneum, 
 in the inferior peroneal groove ; it passes through a groove on the under surface 
 of the cuboid bone ; it is tendinously inserted into the base of the first meta- 
 tarsal bone, having traversed an osseo-aponeurotic canal, from the cuboid bone to 
 its insertion. 
 
 Describe the peroneus brevis. 
 
 It arises from the outer surface of the fibula, middle one-third ; passes behind 
 the external malleolus of the fibula ; passes through the superior peroneal groove, 
 on the outer surface of the calcaneum ; and is inserted into the base of the fifth 
 metatarsal bone. 
 
 Name the grooves through which the tendon of the flexor longus Jiallucis passes. 
 
 This muscle arises from the posterior surface of the fibula, in its middle two- 
 thirds. It passes through a groove in the posterior part of the tibia (Fig. 208) ; 
 through a second groove, in the posterior surface of the astragalus, one inch 
 below the first groove ; through a third groove, on the under surface of the sus- 
 tent'aculum tali of the os calcis or calcaneum ; through a fourth groove, between 
 the two sesamoid bones, in the tendons of the flexor brevis hallucis, at the meta- 
 tarso-phalangeal articulation of the great toe. 
 
 Name the muscles attached to t/ie inferior surface of the os calcis. 
 
 The abductor hallucis, abductor minimi digiti, flexor brevis digitorum, and 
 musculus accessorius. 
 
 Describe tlie insertion of the antagonistic muscles tibia Us anticus and tibialis 
 posticus. 
 
 The tibialis anticus is inserted into the inner surface of the internal cuneiform 
 bone and adjacent part of the base of the first metatarsal bone. (Figs. 2 1 3-2 15.) 
 The tibialis posticus is inserted into the tuberosity of the scaphoid bone, into the 
 sustentaculum tali, into the bases of the second, third, and fourth metatarsal 
 bones, and into all the tarsal bones except the astragalus. 
 
 How shall 'we recognize and knoiv these numerous small insertions of the tibialis 
 posticus muscle ? 
 
 You can easily trace them as small, tendinous bands from the tuberosity of 
 the scaphoid bone to all other insertional points. (Fig. 215.) 
 
 Describe the importance of the sustentaculum tali. 
 
 A superior surface articulates with the inner articular facet of the astragalus ; 
 its inferior surface is grooved and lined by synovial membrane, for the transmis- 
 sion of the tendon of the flexor longus hallucis. 
 
 Give tlie importance of the superior surface of the calcaneum. 
 
 (i) It gives origin to the extensor brevis digitorum ; (2) it articulates with 
 the astragalus by two surfaces. 
 
 What is the importance of the posterior surface of the os calcis ? 
 
 Into this surface is inserted the tendo Achillis. 
 
300 
 
 PRACTICAL ANATOMY. 
 
 SPINE.OF TIBIA 
 
 Internal flbro-cartilage 
 
 Coronary ligament 
 
 Anterior crucial ligament 
 
 INNER TUBEROSITY 
 
 Internal lateral ligament 
 
 Ligamentum patellae 
 
 (Quadriceps extensor) 
 
 Oracilis 
 
 Sartorius 
 
 Semitendinosua 
 
 EXTERNAL SURFACE OF TIBIA 
 Tibialis anticus 
 
 ANTERIOR BORDER OR CREST OF THE TIBIA 
 
 INTERNAL SURFACE OF TIBIA 
 
 Interosneous membrane 
 
 Anterior ligament of ankle-joint. 
 
 Internal lateral ligament 
 
 INTERNAL MALLEOLUS 
 
 External flbro-oartilage 
 Capsule 
 
 OUTER TUBEROSITY 
 
 Biceps and the 
 
 Anterior tibio-flbular ligament 
 
 External lateral ligament 
 
 Extensor longus digitorum 
 
 Peroneus longus 
 
 Peroueus brevli 
 
 Extensor longus digitorum 
 
 PERONEAL SURFACE OF FIBULA 
 
 EXTENSOR SURFACE OF FIBULA 
 Extensor proprius hallucis 
 
 Anterior tibio-flbular ligament 
 
 EXTERNAL MALLEOLUS 
 External lateral ligament 
 (Anterior fasciculus) 
 
 FIG. 207. Tin 1 iii TII;IA AM> FiiiUi.A. (Anterior view.) 
 
THIGH AND LEG. 
 
 POPLITEAL NOTCH 
 
 External flbro-cartilage 
 
 Capsule 
 Posterior crucial ligament 
 
 STYLOID PROCESS 
 Posterior tibio-flbular ligament 
 
 Tibialis posticus 
 
 Flexor lougus hallucii 
 
 FLEXOR SURFACE OF FIBULA 
 
 NUTRIENT FORAMEN 
 
 FIBULA 
 
 Feroneus brevis 
 
 Posterior tibio-flbular ligament 
 
 GROOVE FOR FLEXOR LONGUS HALLUCIS 
 
 External lateral ligament 
 
 (posterior fasciculus) 
 
 External lateral ligament 
 
 (middle 1'asciculusj 
 
 Internal flbro-cartilage 
 Capsule 
 
 Semimembranosus 
 
 Popliteus 
 
 OBLIQUE LINE 
 Soleua 
 
 POSTERIOR SURFACE OF TIBIA 
 
 Flexor longuu digitorum 
 
 TIBIA 
 
 GROOVE FOR T1B1ALIS POSTICUS AND 
 FLEXOR LONGUS DIGITORUM 
 
 Internal lateral ligament 
 
 Posterior ligament of ankle-joint 
 
 FIG. 208. THE LEFT TIBIA AND FIBULA. (Posterior view.) 
 
302 PRACTICAL ANATOMY. 
 
 Locate by limitation tlie medio-tarsal joint, and give the surgical importance 
 thereof. 
 
 Posteriorly, it is limited by the calcaneum and astragalus ; anteriorly, by the 
 cuboid and scaphoid. It is through this articulation the knife passes in Chopart's 
 amputation at the medio-tarsal articulation. 
 
 Locate by limitation the tarso-metatarsal articulation, and give its surgical 
 importance. 
 
 It is limited posteriorly by the cuboid and cuneiform bones ; anteriorly, by 
 the bases of the metatarsal bones. It is through this articulation Lisfranc's 
 amputation is made. 
 
 Locate on the cadaver : (i) The crest of the ilium ; (2) the anterior iliac spine ; 
 (3) the spine of the pubes ; (4) the symphysis pubis ; (5) the pubic crest; (6) 
 the femoral condyles, internal and external ; (7) the tuberosities of the tibia, 
 internal and external ; (8) the head, neck, and styloids of the fibula ; (9) the crest 
 of the tibia ; (10) the subcutaneous inner surface of the tibia ; (i i) the inner and 
 outer malleoli ; (12) the os calcis ; (13) the cuboid bone ; (14) the tuberosity of 
 the scaphoid; (15) the patella and ligamentum patellae; (16) the tubercle of 
 the tibia ; (17) Poupart's ligament or crural arch. 
 
 How to Make Skin Incisions. First cut through the skin from the 
 centre of Poupart's ligament to the centre of the second toe, the incision pass- 
 ing through the mid-line of the patella. The second cut extends along 
 Poupart's ligament, from the anterior superior spine of the ilium to the symphysis 
 pubis. The third cut extends from one femoral condyle to the other. The 
 fourth cut extends from the inner to the outer malleolus. Now remove the 
 skin. Always follow this rule in removing the skin : Cut closely enough to 
 the skin to permit light to shine through. 
 
 THE SUPERFICIAL FASCIA. 
 
 The superficial fascia is the second covering of the body. It contains a vari- 
 able amount of fat. When, as a result of starvation or malnutrition, this fat 
 disappears, the skin lies closely upon the deep fascia, and bony eminences are 
 numerous in other words, the individual is emaciated. This fascia always 
 consists of two layers an upper layer, containing the fat ; a deep layer, in which 
 are found the cutaneous vessels and nerves. The immense fatty mass in the 
 superficial fascia is recorded in the surgical description of operations as the 
 panniculus adiposus. Remember that there are numerous arteries in the super- 
 ficial fascia for the nutrition of the skin, but few of them have special names. 
 Collectively they are known as superficial, dermal, or cutaneous arteries. There 
 are also numerous veins in this fascia. On account of their large size ami 
 surgical importance, quite a number have received special names as long and 
 short saphenous ; still here, too, the rank and file of veins are collectively desig- 
 nated, as are the arteries viz. : superficial, dermal, or cutaneous. By common 
 consent, the word superficial is used by anatomists to designate anything in tlu 
 superficial fascia ; hence all arteries, veins, nerves, muscles, and lymphatics, ii 
 this fascia may properly be collectively designated superficial. 
 
 I laving removed the skin, according to directions previously given, consult 
 figures 209, 210, and 21 1, and find in the deep layer of the superficial fascia the 
 following cutaneous or superficial structures : 
 
 1. The dorsal venous arch of the foot arcus dorsalis peclis. 
 
 2. The long saphenous vein and its tributaries, 
 
 3. The short saphenous vein and its tributaries. 
 
 4. The internal and external femoral cutaneous veins. 
 
 5. The superficial epigastric vein and its tributaries. 
 
 >n 
 
 E 
 
THIGH AND LEG. 
 
 33 
 
 6. The superficial circumflex iliac vein and tributaries. 
 
 7. The superficial external pudic vein. 
 
 8. The spermatic cord, just below the pubic spine. (Fig. 211.) 
 
 9. Superficial inguinal and femoral lymphatic glands. (Fig. 210.) 
 
 10. The long saphenous nerve, with a vein of like name. (Figs. 209 and 210.) 
 
 1 1. The short saphenous nerve and vein (posteriorly). 
 
 12. The cutaneous branch of the musculo-cutaneous nerve. (Fig. 209.) 
 
 13. The internal, middle, and external cutaneous nerves. (Fig. 209.) 
 
 14. The ilio-hypogastric and genito-crural nerves. (Fig. 209.) 
 
 15. The patellar plexus, formed by the union of cutaneous branches, from 
 
 EXTERNAL 
 CUTA- 
 NEOUS 
 
 ILIO- 
 INGUINAL 
 
 TWIG 
 FROM IN- 
 TERNAL 
 CUTA- 
 NEOUS 
 
 INTERNAL 
 CUTA- 
 NEOUS 
 
 PATELLAR 
 BRANCH 
 OF LONG 
 SAPHE- 
 NOUS 
 
 LONG 
 SAPHE- 
 NOUS 
 
 ANTERIOR 
 TIBIAL 
 
 GENITO- 
 CRURAL 
 
 MIDDLE 
 CUTA- 
 NEOUS 
 
 CUTA- 
 NEOUS 
 BRANCH OF 
 EXTERNAL 
 POPLITEAL 
 
 MUSCULO- 
 CUTA- 
 NEOUS 
 
 SHORT 
 SAPHE- 
 NOUS 
 
 FIG. 209. DISTRIBUTION OF CUTANEOUS NERVES ON THE ANTERIOR ASPECT OF THE INFERIOR 
 
 EXTREMITY. 
 
 the internal, middle, external cutaneous nerves, and a branch from the long 
 saphenous and obturator to supply the skin over the insertion of the extensor 
 muscles of the leg, according to Hilton's /aw. (Fig. 211.) 
 
 1 6. The subsartorial plexus, formed by branches from the obturator, long 
 saphenous, and internal cutaneous nerves, to supply the skin over the insertion of 
 the adductors, according to Hilton's lazv. 
 
 17. The prepatellar bursa, found in the superficial fascia in front of the 
 patella. 
 
 Dorsal Arch (Fig. 210.) How Formed. This arch is seen on the dorsum of 
 the foot about one inch behind the clefts of the toes. It is formed by the conflu- 
 ence of the veins from the skin of the toes. It lies upon the cutaneous nerves 
 
PRACTICAL ANATOMY. 
 
 Superficial lymphatics from 
 lateral VOU vf <th<lvnirn 
 
 Superficial epigastric vein 
 
 Lymphatics from penis and 
 
 scrotum 
 Common femoral vein 
 
 Superficial femoral lymphatic 
 
 glands 
 Superficial external pudic vein 
 
 Internal femoral cutaneous vei 
 
 Long saphenous vein 
 
 lower and anterior walls 
 of abdomen 
 
 INTERNAL MALLEOLUS 
 Dorsal venous arch 
 
 FIG. 210. THE SUI-KKHI IAI VKINS AND I.VMI-MA IK s OK THE Lewi K l.i 
 
THIGH AND LEG. 
 
 35 
 
 of the dorsum of the foot. It has two ends, called inner and outer. This vein 
 should be studied on your own feet in this simple way : Tie a bandage very 
 tightly around your leg eight inches below the knee. The pressure will retard 
 the return circulation and make all the superficial veins stand out. 
 
 Long Saphenous Vein. This is the largest and longest superficial vein in 
 the body. It is in the deep layer of the superficial fascia. It is attended by the 
 long saphenous nerve below the knee. It begins at the inner end of the dorsal 
 arch of the foot (arcns dorsalis pedis), passes in front of the internal malleolus, 
 behind the inner tuberosity of the tibia and the inner condyle of the femur, and 
 
 Poupart's ligament 
 
 EXTERNAL CUTANEOUS NERVE 
 MIDDLE CUTANEOUS NERVE 
 OUTER DIVISION OF INTERNAL 
 CUTANEOUS NERVE 
 
 MIDDLE CUTANEOUS NERVE 
 BRANCH TO SARTORIUS 
 
 EXTERNAL CUTANEOUS NERVE 
 
 SUBSARTORIAL PLEXUS 
 OUTER DIVISION OF INTERNAL 
 CUTANEO US NER VE 
 
 OUTER DIVISION OF INTERNAL 
 CUT A NEO US NER VE 
 
 MIDDLE CUTANEOUS NERVE 
 
 Superficial branches of femoral 
 
 artery 
 
 Femoral artery 
 Femoral vein 
 
 INNER DIVISION OF INTERNAL 
 CUTANEO US NER VE 
 
 Saphena vein 
 
 INNER DIVISION OF INTERNAL 
 CUTANEOUS NERVE 
 
 CUTANEOUS BRANCH OF 
 OBTURATOR NERVE 
 
 INNER DIVISION OF INTERNAL 
 CUTANEOUS NERVE 
 
 PATELLAR BRANCH OF LONG 
 SAPHENA 
 
 LONG OR INTERNAL SAPHENOUS 
 NERVE 
 
 FIG. 211. SUPERFICIAL DISSECTION OF THE FRONT OF THE THIGH. 
 (Hirschfeld and Leveille.) 
 
 opens into the common femoral vein, passing through the saphenous opening in 
 the fascia lata. This vein is ligated or obliterated in the radical operation for 
 varicose veins of the lower extremity. (Fig. 210.) 
 
 The Short Saphenous Vein. This begins at the outer end ot the dorsal 
 arch of the foot, passes behind the external malleolus of the fibula, soon gains 
 the posterior mid-line of the leg, passes between the two heads of the gastroc- 
 nemius, and opens into the popliteal vein. This vein is attended by the short 
 saphenous nerve. 
 
 The Long Saphenous Nerve. This is the longest cutaneous nerve in the 
 body. It is a branch of the anterior crural or femoral nerve. It is in Scarpa's 
 
306 PRACTICAL ANATOMY. 
 
 triangle and Hunter's canal. It becomes cutaneous, by piercing the deep fascia, 
 two inches below the knee, between the gracilis and sartorius muscles. It joins 
 company at this place with the vein of like name, and is distributed to the skin 
 of the inner side of the leg, foot, and great toe. This nerve has its extensive 
 distribution below the knee, to supply the fullest insertion of the sartorius 
 muscle and thereby verify Hilton's law. 
 
 The Short Saphenous Nerve. This nerve has a double formation : a 
 branch from the internal popliteal, called the coninninicans tibialis, joins a branch 
 from the external popliteal, called the coninninicans filmlaris, to form this nerve. 
 This union may take place high or low. The nerve accompanies a vein of like 
 name, and is distributed to the skin on the posterior part of the leg and the outer 
 part of the foot and little toe. 
 
 The Cutaneous Branch of the Musculo-cutaneous Nerve (Fig. 209). 
 This is a branch of the external popliteal nerve. The cutaneous branches are 
 distributed to the dorsum of the foot. The muscular branches of this nerve 
 supply the peronei muscles. Anastomosis takes place between these cutaneous 
 branches and also between the plantar nerves on the bottom of the foot, forming 
 the general cutaneous pedal anastomosis. 
 
 The middle cutaneous nerve, a branch of the anterior crural, is usually found 
 as two parallel branches, one of which crosses the sartorius, the other of which 
 pierces the muscle. They end in the patellar plexus, having supplied the skin 
 on the front of the thigh. (Fig. 211.) 
 
 The internal cutaneous nerve, a branch of the anterior crural, supplies the skin 
 of the inner part of the thigh ; supplies the skin over the primary insertion of the 
 sartorius ; assists the obturator in forming the subsartorial plexus, and ends in 
 the patellar plexus. (Fig. 211.) 
 
 What is to be understood by the primary insertion of the sartorius ? 
 
 The insertion of the muscle into the upper and inner one-third of the tibia. 
 (Fig. 207.) The secondary insertion of the muscle is coextensive with the perios- 
 teum of the inner surface of the tibia ; hence to carry out Hilton's law, the long 
 saphenous branch of the anterior crural nerve has its distribution below the knee. 
 
 How do structures become cutaneous / 
 
 Cutaneous nerves become cutaneous by piercing the deep fascia. The ho 
 through which the nerve comes is called an opening, and takes the technical name 
 of the structure transmitted. Where several structures pass through one open- 
 ing, the largest structure lends its name to the opening. Cutaneous structures 
 piercing the deep fascia are centrifugal and centripetal. The former, as nerves 
 and arteries, have their origin below the deep fascia and their explosion in the 
 skin beyond ; the latter, as veins and lymphatics, are made up in the skin, an 
 having collected all their tributaries, pass through the deep fascia, to beco 
 themselves tributary to deep vessels or glands. 
 
 How dissect the cutaneous nerves of tlie t/iig/i / 
 
 There are two procedures, both of which must be closely followed : ( 
 Locate in figure 209 the opening where a given nerve comes through ; the 
 with your forceps, plow through the fat in the long axis of the limb, alwa 
 downward never from side to side until you find the emergence of the nor 
 The location of these openings is never constant ; they may vary several inches 
 in any two cases. After having found the nerve, then trace the same out to i 
 several branches. (2) We trace out the cutaneous nerves of the thigh by loca 
 ing and lifting up, on the finger, the main trunk of the anterior crural nerv< 
 This nerve is found under Ponpart's ligament, beneath the deep fascia, in a groov 
 between the iliacus and psoas magnus muscles. The nerve once on the finger, 
 and on the stretch, now plow downward with the forceps never with the 
 scalpel in the direction of the branches given off. In this way you can find 
 
THIGH AND LEG. 307 
 
 every branch of this nerve. Now, as the anterior crural gives off the internal 
 and middle cutaneous nerves, it yet remains for us to find the external cutaneous 
 nerve. 
 
 The External Cutaneous Nerve. This is a branch of the lumbar plexus. 
 You find its main trunk by cutting through the deep fascia just below the 
 anterior superior iliac spine. Its branches are to be traced out in a manner 
 similar to the others. The cutaneous nerves of the anterior region of the thigh, 
 above referred to, become cutaneous, in average, at the junction of the upper and 
 middle one-third of the thigh. They divide into many branches each, and 
 collectively supply with sensation the front, outer .and inner parts of the thigh, 
 as far as the knee. At this place they all communicate to form the plexus 
 patellae, above described. 
 
 The student should remember that while the external cutaneous nerve is 
 usually given in the text-books as a separate nerve of the lumbar plexus, still, 
 physiologically and rationally this nerve must be considered as a divorced or 
 dismembered branch of the anterior crural or femoral nerve, for this reason : The 
 nerve -trunk that supplies muscles, supplies the skin over the muscle, even to the 
 fullest insertion. Now, the anterior crural nerve supplies the extensor group of 
 muscles on the anterior and outer part of the thigh, hence the external cutane- 
 ous belongs philosophically to the anterior crural nerve, being divorced therefrom. 
 Such cases will frequently be met. The small sciatic is the divorced cutaneous 
 part of the great sciatic nerve. 
 
 The spermatic cord must be noticed in this section, on account of its 
 important relation to two nerves and two arteries. You will find the spermatic 
 cord emerging from the inguinal canal, by the external abdominal ring (Fig. 163). 
 From this time on it is a cutaneous structure, because it is in the superficial 
 fascia. With your scissors trace the cord into the scrotum, by cutting through 
 the skin and superficial fascia. On the front of the cord you will find a little 
 nerve, the ilio-inguinal ; behind the cord you find the genital branch of the genito- 
 crural nerve. These nerves come from the lumbar plexus. The ilio-inguinal 
 nerve supplies the side of the thigh and the scrotum ; the genital branch of the 
 genito-crural supplies the cremaster in the male, and is lost on the round liga- 
 ment in the female. The arteries in relation with the spermatic cord are the 
 superficial and deep external pudics, branches of the common femoral ; the former 
 is in front of the cord, the latter behind the cord. 
 
 THE DEEP FASCIA OF THE THIGH AND LEG. 
 
 In figure 210 the glistening structure, upon which the long saphenous vein 
 and its tributaries rest, is the outer or circumferential part of the deep fascia of 
 the lower extremity. The internal or central part of the deep fascia is, conse- 
 quently, surrounded by the external. In looking at a well-filled comb of honey, 
 you see only a small part of the honey-comb the outside limiting part. If, 
 however, you extract the honey, then you can see and examine the interior cel- 
 lular arrangements ; in other words, you can examine the internal divisions of 
 the connective tissue or deep fascia of the honey-comb. It is just so in examin- 
 ing the internal parts of the deep fascia of the thigh or of any organ of the body. 
 The deep part of the deep fascia corresponds to the cellular-tissue spaces of the 
 honey-comb. The spaces are occupied, not by one substance, but by many. 
 Muscles, vessels, bone, nerves, fat, glands, and all the compounds which make 
 up the limb occupy large spaces, just as effectually shut off from one another as 
 is the honey in one cell separated from that in another in the comb. 
 
 Physiological division of labor and differential assimilation cause grouping of 
 like compounds. This grouping of muscles takes place on the physiological 
 
308 PRACTICAL ANATOMY. 
 
 basis of antagonism. Flexors oppose extensors ; adductors oppose abductors ; 
 pronators oppose supinators ; levators oppose depressors. Nerves that inner- 
 vate and vessels that feed them are as truly antagonistic as are the muscles. 
 
 The general/ /aw of antagonism is this: equality in length, strength, blood, 
 nerve, and fascial environment. Antagonistic groups of muscles are separated 
 from each other by deep fascia, called septa. A group of muscles acting in 
 unison, as the extensors or flexors of the leg, is called a musculature. Adjacent 
 musculatures are separated from each other by deep fascia, called septa. The 
 individual muscles, of which groups are composed, are also separated by deep 
 fascia. Bone is surrounded by deep fascia, called periosteum ; articulations are 
 held in place by deep fascia, called capsular ligament. Vessels and nerves receive 
 their sheath, and glands their capsules from deep fascia i. t\, from the internal 
 division of the same. 
 
 Minor Details. With this understanding of the general distribution of the 
 deep fascia of the thigh, consider some of the minor details : 
 
 1. One characteristic of deep fascia is the presence of openings in the outer 
 or circumferential portion, for the transmission of both centripetal and centrifugal 
 cutaneous vessels and nerves ; in the central or septal portions for the trans- 
 mission of those branches of antagonistic vessels and nerves, called communi- 
 cating and anastomotic, which preserve a physiological balance of power. 
 Instance, the perforating branches of the profunda reaching the hamstrings, 
 and the communications between the anterior crural, obturator, and great sciatic 
 nerves. 
 
 2. Deep fascia is not uniform in tldckness. As structure is the correlative of 
 function, those parts subjected to the greatest degree of tension and use must 
 become thick and strong in comparison with less used parts. 
 
 3. Deep fascia of the leg and thigh receives in some localities special names, 
 founded on no rational or logical ground, but which are perpetuated in anatomy 
 and surgery, and revered, as Egypt points to her ruins. The special names for 
 the deep fascia of the lower extremity are these : (i) The fascia la fa, on the 
 upper front part of the thigh ; (2) the ilio-tibial band, on the outer side of the 
 thigh ; (3) the popliteal fascia, covering the popliteal space ; (4) the internal 
 annular ligament, between the os calcis and internal malleolus ; (5) the external 
 annular ligament, between the os calcis and external malleolus ; (6) the anterior 
 annular ligament, between the malleoli ; (7) the dorsal fascia, on the back of the 
 foot ; (8) the plantar fascia on the sole of the foot ; (9) the ligamcnta vaginalcs 
 as sheaths for the flexor tendons of the toes; (10) the vincula, as interter 
 dinous slips ; (i i) the various intermuscular septa. 
 
 4. Deep Fascia Gives Origin and Insertion to Muscles. This fact is often IK 
 fully appreciated by the student. Instance, the -rastus interims and rastns 
 cxtcrnus, the muscles on the anterior part of the tibia andjftfat/a. Be ever ready 
 to see deep fascia giving origin or insertion to muscles. The glutens maximus 
 has one-of its insertionsjnto the deep fascia ; the ilio-tibial band is in reality only 
 the insertion of the tensor vagina; femoris, by aponeurosis. 
 
 5. Sn/x/irisions of fascia lata are : (i) the iliac and (2) pubic portions. These 
 are separated from each other by a large opening the saphenous. The iliac or 
 anterior portion is attached to the crest of the ilium, to the whole of Poupntt's 
 ligament. The pubic or posterior part covers the pcctineus muscle and gracilis ; 
 is continuous with the femoral sheath behind the femoral vessels. 
 
 Attachments of Ar/> I'\rscin. Deep fascia is continuous with periosteum at 
 subcut.HH-oiis areas. These are called the attachments. Tin- deep fascial attach- 
 ments of the lower limb are as follows. In the region of the hip : (i) To crest ot 
 ilium ; (2) to pubic spine and body ; (3) to ischii. -pubic ramus ; (4) to the tubcr- 
 usity of ischium ; (5) to sacrum and coccyx. In the knee region, demonstrate 
 
THIGH AND LEG. 
 
 39 
 
 its attachment to : (i) The patella ; (2) the tuberosities ; (3) the condyles ; (4) 
 the crest and inner surface of the tibia. In the ankle region, see its attachment : 
 (i) To the os calcis ; (2) to the malleoli ; (3) to the tuberosity of the scaphoid 
 bone and numerous other places. 
 
 Saphenous Opening. This is the largest opening in the deep fascia. It is 
 situated between the iliac and pubic portions of the fascia lata. Behind it, or on its 
 floor, is the femoral sheath, containing the femoral artery, vein, and canal. In 
 front of the opening, forming its roof or covering, is the superficial fascia, called 
 in this locality, the cribriform fascia. The structures passing through the 
 saphenous opening are numerous : the long saphenous vein and the small vessels 
 given off from the common femoral artery and vein, and some lymphatic vessels. 
 
 Cribriform Fascia. Just that part of the deep layer of the superficial fascia, 
 that covers the saphenous opening, is called by this name. It was so called on 
 account of the numerous perforations, transmitting the structures referred to in 
 the previous paragraph. The word " cribriform " means sieve-like. 
 
 Importance. Since fascia often determines the direction taken by burrowing 
 pus, or the course of a bullet, its various superficial attachments should be care- 
 
 FIG. 212. THE FEMORAL RING AND SAPHENOUS OPKNING. (After Holden.) 
 
 (The arrow is introduced into the femoral ring.) 
 
 i. Crural arch. 2. Saphenous opening of the fascia lata. 3. Saphena vein. 4. Femoral vein. 
 5. Gimbernat's ligament. 6. External abdominal ring. 7. Position of internal ring. 
 
 fully examined, and its deep ones found by dissection. The guide to finding 
 these is to remember that muscles are arranged in antagonistic groups, and that 
 these groups are called musculatures, and that these musculatures are separated by 
 septa, and these septa are attached to bone i. e., continuous with its periosteum. 
 
 The Application. Now apply the principle of musculatures to the lower ex- 
 tremity. On the thigh you will presently find: (i) An extensor group of mus- 
 cles in front ; (2) a flexor group behind ; (3) an adductor group internally. 
 
 You will also find: (i) A septum between the extensor group and flexor 
 group ; (2) between the flexor group and the adductor group ; (3) between the 
 adductor group and the extensor group. 
 
 Again, below the knee you will find : (i) A group of muscles on the anterior 
 tibio-fibular region ; (2) a group on the outer surface of the fibula ; (3) two groups 
 on the posterior tibio-fibular region. Here, also, you may demonstrate the rule 
 that adjacent musculatures are separated from one another by fascial septa, since 
 here are strong bands of fascia separating the peronei muscles on the outer sur- 
 face of the fibula, from different musculatures both in front and behind. Like- 
 wise, on the back of the leg, the superficial group is separated from the deep by 
 the transverse fascia, and both these groups from lateral musculatures. 
 
310 PRACTICAL ANATOMY. 
 
 ANTERIOR REGION OF LEG. 
 
 Remove carefully the deep fascia. (Fig. 210.) You have now, by the re- 
 moval of the skin and superficial fascia, exposed the deep fascia covering all the 
 muscles on the anterior and outer regions of the leg (Fig. 213): 
 
 1. The cutaneous branch of the musculo-cutaneous nerve. 
 
 2. The tibialis anticus and the tuberosity of scaphoid bone. 
 
 3. The extensor proprius hallucis muscle. 
 
 4. The extensor longus digitorum muscle. 
 
 5. The peroneus tertius muscle. 
 
 6. The extensor brevis digitorum muscle. 
 
 Now dissect down between the tibialis anticus and the extensor proprius 
 hallucis by cutting through the deep fascia with scissors and find the anterior 
 tibial nerve and vessels. (Fig. 214.) 
 
 Anterior Tibial Artery. It is one of the two terminal branches of the pop- 
 liteal artery. It gains the front of the leg by passing between the two heads of 
 the tibialis posticus and interosseous membrane. It lies in a deep groove, bounded 
 internally by the tibialis anticus ; externally, by the extensor longus digitorum 
 and extensor proprius hallucis. It terminates on the dorsum of the foot, continu- 
 ing its course under the name of dorsalis pedis. Its branches are : (i) The ante- 
 rior tibial recurrent, which anastomoses with the articular branches of the popliteal 
 and anastomotica magna ; (2) posterior tibial recurrent, when present, is given off 
 before the anterior tibial passes through the interosseous membrane ; (3) mus- 
 cular branches, which supply the muscles on the anterior region of the leg (Fig. 
 214) ; (4) malleolar branches, which supply the ankle-joint. On the back of the 
 foot you cut through the deep fascia between the extensor proprius hallucis and 
 extensor, longus digitorum muscles, to find the dorsalis pedis artery. 
 
 Dorsalis Pedis Artery. This is a continuation of the anterior tibial. It lies 
 between the extensor proprius hallucis and extensor longus digitorum, on the 
 dorsum of the foot. (Fig. 214.) It gives off: (i) A communicating branch to 
 the external plantar, by which the plantar arch is completed ; (2) a tarsal 
 artery to the extensor brevis digitorum and the tarsus ; (3) the dorsalis hallucis 
 to the great toe ; (4) interosseous arteries to the interosseous spaces and their 
 contents. Trace the arteries out carefully with the forceps. Remember they 
 are beneath the dorsal fascia. 
 
 Anterior Tibial Nerve. It is a branch of the external popliteal nerve, being 
 given off with the musculo-cutaneous nerve. It gives off articular branches, ac- 
 cording to Hilton's law, to the (i) ankle-joint, (2) the tarsal, and (3) the metatarsi 
 phalangeal joints. It gives muscular branches to the extensor brevis digitorui 
 and to all the muscles on the anterior regions of the tibia and fibula. 
 
 Muscles on Anterior Surface of Fibula. These are : (i) Extensor proprius 
 hallucis ; (2) extensor Jongus digitorum ; (3) peroneous tertius, the fifth tender 
 of the extensor longus digitorum. 
 
 Insertion of Extensor Brevis Digitorum. This muscle has four tendon- 
 The first is inserted independently into the base of the first phalanx of the great 
 toe ; the remaining three are inserted, conjointly with the tendons of the 
 extensor longus digitorum, into the bases of the second and third phalanges. 
 
 Give nen>e-supply of the Jive tmtsc/cs nw exposed on the anterior tibio-filntlar 
 region. 
 
 The anterior tibial, a branch of the external popliteal 
 
 Intermuscular Septum. Examine the septum that separates the muscles 
 the anterior surface of the fibula from the peronei on the external surface. 
 
 How to Dissect these Muscles. Tibialis Anticus. Cut through tl 
 
 I 
 
 us 
 
 ;: 
 
THIGH AND LEG. 311 
 
 anterior annular ligament on the tendon of the muscle. Now follow the 
 tendon to its insertion into the internal cuneiform bone and base of the 
 
 Ligamentum patellae 
 
 CiastrocnemiuB 
 
 Extensor propriua halluei 
 
 Dorsal interoasei 
 
 Peroueus longus 
 
 Tibiaha anticus 
 
 Peroneus tertius 
 
 Extensor loagua digitorum 
 
 Peroneus tertius 
 
 Extensor brevis digitorum 
 
 FIG. 213. THE MUSCLES OF THE FRONT OF THE LEG. 
 
 first metatarsal. Then trace the muscle to its origin : (i) the outer surface of the 
 tibia, upper two-thirds ; (2) outer tuberosity. Notice the nerve-supply and blood- 
 sijpply. 
 
312 
 
 PRACTICAL ANATOMY. 
 
 Extensor Proprins Hallucis. Begin at the end of the great toe and cut down 
 on the tendon. Follow it up through a separate compartment under the 
 
 Superior internal articular artery 
 
 Inferior internal articular artery 
 
 Anterior tibial recurrent artery 
 
 Anterior tibial artery 
 
 Tibialis anticus muscle 
 
 ANTERIOR TIBIAL NERVE 
 
 Extensor longuB halluois 
 
 Internal malleolar artery 
 
 Anterior annular ligament 
 Dnrsalis pedis artery 
 
 Innermost tendon of extensor 
 brevis digitorum 
 
 Comitiuiiicntinij branch 
 Dorsalis hallucis artery 
 
 Superior external articular artery 
 
 Inferior external articular artery 
 
 Extensor longus digitorum 
 
 Extensor longus digitorum. 
 turned back 
 
 Peroneus tertiua 
 
 Anterior peroneal artery 
 
 External malleolar artery 
 
 Peroneus brevis muscle 
 
 1\ 
 
 ift Extensor brevis digitorui 
 
 External tarsal branch 
 
 Metatanal branch 
 
 Dorsal inlerosseous artery 
 
 FIG. 214. THK ANTKRIOK TlBIAl ARTERY, DORSAL ARTKRY OF THK FOOT, AM> AMKKH 
 I'KROM-.AI. ARTKRY, AND TIIKIR BRANCH M. 
 
 annular ligament to its origin on the middle half of the anterior surface of the 
 fibula and interossrous membrane. 
 
 The licensor Longus nigitornw. To dissect this muscle successfully, c nl 
 
THIGH AND LEG. 313 
 
 down on the same through the anterior annular ligament. Then use your 
 forceps as a director, and carefully cut the dorsal fascia over each of the four 
 
 Teudo Achillis 
 
 Extensor brevis 
 
 digitorum 
 
 Extensor longue 
 
 halluois 
 
 Extensor brevis 
 digitorum 
 
 Peroneus brevis 
 
 Peroneus tertius 
 
 METATARSUS 
 
 FIRST PHALANX 
 
 SECOND PHALANX 
 THIRD PHALANX 
 
 cteusor longus digitorum 
 
 FIG. 215. THE LEFT FOOT. (Dorsal surface.) 
 (Study origin and insertion of muscles on this figure and compare with your dissection.) 
 
 'tendons. In like manner trace each tendon to the end of the toe. Notice that 
 each tendon divides in three slips, on the dorsal surface of the first phalanx ; 
 that the middle slip is inserted into the base of the second phalanx ; that the 
 
 21 
 
3*4 
 
 PRACTICAL ANATOMY. 
 
 SPINE, OF TIBIA 
 
 Internal nbro-cartilage 
 
 Coronary ligament 
 
 Anterior crucial ligament 
 
 INNER TUBEROSITY 
 
 Internal lateral ligament 
 
 Ligamentum patellae 
 
 (Quadriceps extensor) 
 
 Gracilis 
 
 Sartorius 
 
 SemitendinoauB 
 
 EXTERNAL SURFACE OF TIBIA 
 Tibialis anticus 
 
 ANTtRIOR BORDER OR CREST OF THE TIBIA 
 
 INTERNAL SURFACE OF TIBIA 
 
 InteroBBeous membrane 
 
 Interior ligament of ankle-joint 
 
 Internal lateral ligament 
 
 INTERNAL MALLEOLUS 
 
 External nbro-cartilage 
 Capsule 
 
 OUTER TUBEROSITY 
 
 Biceps and the 
 
 Anterior tibio-flbular ligament 
 
 External lateral ligament 
 
 Extensor longus digitorum 
 
 Peroneus lougus 
 
 Peroneus brevls 
 
 PERONEAL SURFACE OF FIBULA 
 
 EXTENSOR SURFACE OF FIBULA 
 Extensor propriua haliucis 
 
 FIBULA 
 
 Peroneus tertius 
 
 SUBCUTANEOUS PORTION 
 
 Anterior tibio-flbular ligament 
 
 EXTERNAL MALLEOLUS 
 External lateral ligament 
 (Anterior fasciculus) 
 
 FIG. 216. THE LEFT THIIA AND FIHUI.A. (Anterior view.) 
 (Study origin of muscles on this figure and compare with your dissection.) 
 
THIGH AND LEG. 315 
 
 two lateral slips are inserted into the base of the third phalanx. Also notice 
 the relation of the tendons of this muscle to those of the extensor brevis digi- 
 torum. Origin, outer tuberosity of the tibia and anterior surface of fibula. 
 
 The Peroneus Tertius. Find the insertion of this muscle in the base of the 
 fifth metatarsal. (Fig. 215.) Trace it to the anterior surface of the fibula, and notice 
 that it blends with the preceding muscle, a part of which it really is. (Fig. 207.) 
 
 THIGH, ANTERIOR AND INTERNAL REGIONS. 
 
 Remove the deep fascia and expose the vessels, nerves, and muscles. (Figs. 
 218, 219, and 220.) 
 
 First locate the sartorius. (Fig. 218.) Begin at the anterior superior iliac spine 
 (Fig. 226) and expose the muscle to its insertion (Fig. 207) into the tibia, by gently 
 removing all deep fascia. Now lift up the muscle from its bed, taking care not to 
 damage the vessels and nerves that enter it. Notice that this muscle is crossed by 
 one and pierced by another branch of the middle cutaneous nerve. (Fig. 211.) 
 
 Locate the gracilis next, on the inner surface of the thigh. (Figs. 218 and 
 219.) Trace it from the descending ramus of the pubes (Fig. 226) to its inser- 
 tion into the inner surface of the tibia (Fig. 207), taking care not to damage 
 the nerve branches of the obturator that enter it. This dissecting, by which 
 this muscle is separated from its fellow-muscles, must be done with the forceps. 
 
 Locate the adductor longus. (Fig. 218.) Trace it from the anterior surface 
 of the pubes to its insertion into the middle of the middle lip of the linea aspera. 
 (Fig. 227.) Divide the connective tissue between this muscle and the pectineus. 
 (Fig. 218.) Now cut the adductor longus, at its origin, and turn the same 
 aside. (Fig. 219.) Also cut the pectineus and turn it aside. (Fig. 218.) 
 
 Obturator Nerve, Anterior Division (Fig. 219). This you will see lying on 
 the adductor brevis. (Fig. 219.) Take this nerve up gently, and follow out its 
 branches to : (i) The gracilis ; (2) the adductor longus ; (3) the adductor brevis ; (4) 
 the sartorius ; (5) a branch to the hip-joint ; (6) a branch to the femoral artery ; (7) 
 an occasional branch to the pectineus muscle ; (8) a cutaneous branch to assist the 
 long saphenous and internal cutaneous in forming the subsartorial plexus. 
 
 Obturator Nerve, Posterior Division. This lies on the adductor magnus. 
 The adductor brevis muscle then separates the anterior from the posterior divi- 
 sion of the nerve. This division supplies : (i) The obturator externus ; (2) the 
 adductor magnus; (3) an articular branch to the hip-joint; (4) an articular 
 branch to the knee. 
 
 Why does the obturator nerve send a branch to the knee ? 
 
 Because this nerve supplies the sartorius muscle, a muscle that moves the 
 knee-joint. (Fig. 219.) 
 
 Hoiv does the articular branch from the obturator nerve enter the hip-joint / 
 
 It passes through the cotyloid notch. 
 
 When the accessory obturator nerve is present, wliere may it be found / 
 
 To the inner side of the psoas magnus muscle. 
 
 What is the function of the subsartorial plexus? 
 
 To supply the skin over the adductor muscles, and to exercise a sensory 
 balance of power between the obturator and anterior crural nerves. 
 
 The Anterior Crural Nerve (Fig. 219). You will find the main trunk of this 
 nerve deeply buried in a space between the iliacus and psoas magnus. (Fig. 197.) 
 Take this nerve up on your finger and gently follow out its muscular branches to 
 all the muscles on the front of the thigh : (i) Sartorius ; (2) rectus femoris ; (3) 
 
PRACTICAL ANATOMY. 
 
 vastus internus ; (4) vastus externus ; (5) crureus ; (6) subcrureus ; (7) pectineus. 
 In tracing these nerves, divide the connective tissue in the direction of the long axis 
 
 EXTERNAL POPLITEAL 
 
 NER VE 
 RECURRENT ARTICULAR 
 
 MUSCULO-CUTANEO US 
 
 BRANCH TO PERONEUS 
 LONG US 
 
 BRANCH TO EXTENSOR 
 LONG US DIG I TO RUM 
 
 BRANCH TO PERONEUS 
 B RE VIS 
 
 MUSCULO-CUTANEO US 
 
 MUSCUL O-CUTA NEO US 
 
 (OI'TKIt 
 
 S1IOR T SA PHENO US 
 
 COLLA TERA I, 
 BRAN<'lli-:x OF EX- 
 
 //;/.' .V.I/, XAP/fENOUS 
 .I.Y/J .vr.sYV/.o- 
 CUTAM:nrs TO TOES 
 
 ANTERIOR TIBIAL 
 
 SKI: vi-: 
 
 Anterior tibial artery 
 
 Tibialia anticua 
 
 ANTERIOR TIBIAL 
 NERVE 
 
 M U8CULO-CUTA Si-:< > ' w 
 (INNER DIVISION) 
 
 ANTERIOR TIBIAL 
 
 (<>r n-:i: />/V/ 
 
 //> ItlsTIUHCTION TO 
 
 DIGITORUM 
 
 ANTEIUOi: TIlilAL 
 
 d.\.\i:i; i>i VISION) 
 
 COLLATERAL 
 
 .v< ///> or 
 rxrr /.<>-(//. i. \/-:o i .s 
 
 ) co/,/,.1 TV?/? 
 BRANCHl 
 MU8CULC 
 TO TOES 
 
 l-'lC. 217. BkAN'CHES OF THE E.Vl'KKN.U. 1'ol'l.lTKAI. NhK\l. 
 
 of the ncrrc nc-rcr crossivise. And trace it to the skin covering the same by 
 
 (i) The internal cutaneous ; (2) the middle cutaneous ; (3) the long saphenou.< 
 
 The Femoral Artery (Fig. 223). Get your finger under this vessel and trac 
 
THIGH AND LEG. 
 
 317 
 
 out its branches. Great care must be taken to divide the connective tissue binding 
 the artery and vein together. To learn the branches of this artery, see page 
 320. 
 
 Dissection of the Rectus (Fig. 2 1 8). You can easily lift this muscle from its 
 b^d. It lies on the vastus interims. (Fig. 220.) Joining the rectus on its outer 
 
 Adductor brevis 
 
 Adductor longua 
 
 Adductor magnus 
 
 Vastus InternuB 
 
 Tendon of sartorius 
 
 Gluteus medius 
 
 Glutens minimus 
 Tensor vaginae femoria 
 
 Sartorius 
 
 - Rectus femoris 
 
 o-tibial band of fascia lata 
 
 astua ezternus 
 
 Ligamentum patellae 
 
 Fir,. 2l8. MUSCLES OF THE FRONT OF THE THIGH. 
 
 border is the vastus cxternus. (Fig. 2 1 8.) Trace the rectus upward and develop its 
 two heads (Fig. 226) : (i) The straight, from the anterior inferior iliac spine ; (2) the 
 reflected, from the depression above the brim of the acetabulum. Notice the nerves 
 and arteries enter the under surface, and trace them to their sources. (Fig. 223.) 
 
3i8 PRACTICAL ANATOMY. 
 
 The Vasti Internus and Externus (Fig. 220). Cut the rectus four inches 
 above the patella and turn it aside, guarding well the vessels and nerves. You 
 will take particular notice of the form of the groove or bed in which the rectus 
 lay. This bed is on the front surface of the vastus internus, and is called the 
 crureus^ muscle. (Fig. 220.) It is not a separate muscle, but only that part of the 
 vastus internus on which the rectus lay. Along the outer margin of the rectus-bed 
 you will see the descending branch of the external circumflex artery (Fig. 223), 
 
 Femoral vein 
 
 Femoral artery 
 
 I 
 
 Pectineus 
 OBTURATOR (ANTERIOR DIV.) 
 
 OBTURATOR (POSTERIOR 
 DIVISION) 
 
 Adductor longus 
 
 Adductor brevis 
 
 OBTURATOR 
 (ANTERIOR 
 DIVISION) 
 
 Oracilis 
 
 Adductor magnus 
 
 GENICULA TE 
 BRANCH OF 
 OBTURATOR 
 
 Seml-membranoBUB 
 
 Anoitomotica artery 
 
 PA TELLAR BRANCH OF 
 LONG SAPHENOUS 
 
 Sartorlua 
 Iliacus 
 
 ANTERIOR CRURAL 
 
 Psoas 
 
 Tensor vaginae femoris 
 
 Prqfunda artery 
 
 Fectineus 
 Hectus femoris 
 
 LONG SAPHENOUS 
 
 NERVE TO VASTUS 
 IN TERN US 
 
 Adductor lonftus 
 
 Femoral artery 
 
 FIG. 219. ANTERIOR CRIKAI AND < IUTURATOR NERVES. (Ellis.) 
 
 attended by the nerve to the vastus externus. This artery lies in a groove which 
 separates the vastus internus from the vastus externus. Develop this groove, 
 and you will be able to turn the vastus externus aside. This latter muscle, the 
 vastus externus, overlaps the outer part of the vastus interims as far as the margin 
 of the rectus. (Fig. 218.) Now trace the rectus and the two vasti downward to 
 their conjoined insertion into the tubercle of the tibia, by the ligamentum patelhe. 
 (Fig. 216.) Also note that the vastus internus receives its nerve-supply on ib 
 anterior surface. (Fig. 219.) 
 
 Obturator Nerve (Fig. 219). This is a branch of the lumbar plexus. It passe.- 
 
THIGH AND LEG. 
 
 below the brim of the pelvis, with the obturator artery and vein. (Fig. 223.) It 
 escapes from the pelvis by the obturator canal, on the under surface of the hori- 
 zontal ramus of the pubes. It divides into anterior and posterior branches. These 
 are separated by the adductor brevis muscle. (Fig. 219.) The anterior branch 
 
 Obturator externus 
 
 Adductor longus 
 
 Adductor magnus 
 
 Adductor longus 
 
 Vastus internus 
 
 Reotua femoris 
 
 Xiigamentum patellae 
 
 Reotua tendon 
 
 GHuteus medius 
 Gluteus minimus 
 
 Adductor brevis 
 
 Vastus ezternus 
 
 Biceps 
 
 Ilio-tibial band 
 
 FIG. 220. THE DEEP MUSCLES OF THE^ FRONT OF THE THIGH. 
 
 supplies the graciiis, adductor longus, adductor brevis, and sartorius. (Fig. 221.) 
 The posterior branch supplies the adductor magnus, the knee, and the hip. 
 
 Branches of the Anterior Crural Nerve. This nerve is from the lumbar 
 plexus. (Fig. 193.) It is in a groove under the crural arch between the iliacus 
 and psoas magnus. It gives off the following branches : 
 
320 
 
 PRACTICAL ANATOMY. 
 
 1. A branch to the iliacns muscle. This is given off within the pelvis, but is 
 easily found distributed to the under surface of the muscle. 
 
 2. Cutaneous brandies the long saphenous, the internal and middle 
 cutaneous. 
 
 3. A small branch to the femoral artery. This is given off within the pelvis. 
 
 4. Muscular branches to all the muscles on the front of the thigh. Note 
 that the sartorius muscle is supplied either by the middle or internal cutaneous 
 nerve. 
 
 5. An articular brancJi to the hip, given off from the branch to the rectus ; 
 also articular branches to the knee, from the nerves to the two vasti. 
 
 FIG. 221. PECTIN EUS AND ADDUCTOR LONGUS. 
 I. Femur. 2. Ilium. 3. Pubis. 4. Pectineus. 
 
 5. Adductor longus. 6. Lower portion of 
 
 adductor magnus. 7. Tendon of rectus femoris. 
 
 8, 8. Orifices for vessels. 9. Orifices for femoral 
 
 vessels. 
 
 FIG. 222. ADDUCTOR BRKVIS AND AI>DU 
 
 MAGNUS. 
 
 . Femur. 2. Ilium. 3. Pubis. 4. Obturator 
 externus. 5- Upper portion of adductor magnus. 
 6. Upper portion of adductor brevis. 7. Inferior 
 portion of adductor brevis. 8. Middle portion 
 of adductor magnu. 9. Inferior portion. lo. 
 Tendon of insertion into internal condyle o 
 femur. n. Orifice for femoral vessels. 12. 
 Orifice for internal circumflex artery and veins. 
 
 
 Branches of the Femoral Artery. The common femoral is a continuation 
 of the external iliac. (Fig. 223.) Usually, it is about one and one-half inches in 
 length. It then divides into the superficial and deep femoral. F.ach has branches. 
 
 Branches of the Common Femoral Artery. (i) Superficial circumflex 
 iliac ; (2) superficial epigastric ; (3) superficial external pudic ; (4) deep external 
 pudic. These are all small and surgically insignificant branches. (Fig. 223.) 
 
 Branches of the Profunda. (i) The internal circumflex ; (2) the external 
 circumflex ; (3) the three perforating arteries. 
 arc perforating arteries so called .' 
 
 1 1 
 
THIGH AND LEG. 321 
 
 Because they perforate the adductor group, to reach the hamstring muscles 
 on the back of the thigh, which they supply. (Fig. 222.) 
 
 The external circumflex supplies the muscles on the anterior part of the 
 thigh. (Fig. 223.) Its ascending branch anastomoses with the gluteal and 
 circumflex iliac; its descending branch with the superior external articular branch 
 of the popliteal artery. 
 
 The Use of the Internal Circumflex (Fig. 223). To assist the obturator 
 artery in supplying the hip-joint and the adductor muscles, and to anastomose 
 with the sciatic and external circumflex to complete the crucial anastomosis. 
 
 \\ r kcre, on the posterior part of tlic thigh, will you find the terminal branch of 
 the internal circumflex arterv f 
 
 Between the quadratus femoris and the adductor magnus. 
 
 Branches of the Superficial Femoral Artery. The superficial femoral 
 artery lies in both Scarpa's triangle and Hunter's canal surgical areas to be pres- 
 ently described. The branches given off by this artery are : muscular, to the sar- 
 torius and vastus interims ; the anastomotica magna, given off just before the 
 artery leaves Hunter's canal. 
 
 The anastomotica niagna divides into two branches: (i) A superficial one, 
 that accompanies the long saphenous nerve, and (2) a deep one, that anastomoses 
 with the internal articular and the anterior recurrent tibial. This artery supplies 
 branches to the knee-joint. It will be found on the bone, above the condyle, 
 forming an arch with the external articular. 
 
 Review of tlic Work on the Thigh. Thus far in the deep dissection of the an- 
 terior and lateral regions of the thigh, you have : 
 
 1. Traced the origin, insertion, and nerve-supply of the sartorius, and lifted 
 this muscle from its bed. 
 
 2. You have found the exact origin and insertion of the gracilis, and liberated 
 the same without doing violence to its nerves and blood-vessels. 
 
 3. You have traced the adductor longus from origin to insertion, preserved 
 its nerves, cut the origin of the muscle, and seen the anterior division of the 
 obturator nerve lying below, on the adductor brevis muscle ; and the branches of 
 this nerve you have followed to four muscles. 
 
 4. You have located the anterior crural nerve in a space between the psoas 
 magnus and iliacus, taken this nerve up, and traced out its branches to the muscles 
 on the front part of the thigh and to the skin covering these muscles and to the 
 joints these muscles move. 
 
 5. You have removed the rectus from its bed, traced the same to its origins, 
 and preserved the nerve- and blood-supply ; finally, you have cut the rectus four 
 inches above the patella. 
 
 6. You have seen that the crureus is not a separate muscle, but a part of the 
 vastus intern us. 
 
 7. You have traced the femoral artery well down and studied its profunda 
 division. 
 
 8. You have traced the vasti and rectus to their common insertion into the 
 tubercle of the tibia by the ligamentum patella:,. 
 
 What to Dissect Next. (i) Cut the origin of the adductor brevis (Fig. 220), 
 gently lift the same, and see the posterior division of the obturator nerve. Trace 
 this nerve to the adductor magnus and obturator externns muscles. (2) Cut the 
 pectineus (Fig. 219) and turn it down. Now, on the outer surface of the obturator 
 externns muscle you will find the o bturator artery, anastomosing with the internal 
 circumflex, a branch of the profunda. (Fig. 223.) (3) Now you may replace 
 in this order the muscles you have cut and turned aside : (a) Pectineus, (^) 
 adductor brevis, (r) adductor longus, (d) rectus. Place the sartorius in its 
 original oblique position. 
 
3 22 
 
 PRACTICAL ANATOMY. 
 
 Two Important Surgical Areas. Scarpas triangle and Hunter s canal. 
 
 Scarpa's triangle is located on the upper anterior one-third of the thigh. It 
 is divided into an inner and an outer part by the femoral vessels, which bisect the 
 space vertically. It is of surgical importance for the following reasons : 
 
 1. Inguinal and femoral herniae are seen here. 
 
 2. Varicocele, dilatation of scrotal or spermatic veins. 
 
 3. Removal of inguinal lymphatic glands may become necessary. 
 
 4. Fracture of the femur and dislocations of its head. 
 
 Common iliac artery 
 SYMPA THETIC NER VE 
 
 Middle sacral artery 
 
 Common iliac vein 
 URETER 
 
 Internal iliac artery 
 
 External iliac vein 
 
 External iliac artery 
 
 Potterior branch of internal iliac dividing into 
 gluteal and ilio-lumbar arteries 
 
 Lateral sacral artery 
 
 SACRAL PLEXUS 
 
 OBTURATOR NERVE 
 Obturator artery 
 Obliterated hypngastric 
 
 Superior vetical artery 
 Edge of levator ani 
 
 Pudic artery 
 
 BLADDER 
 
 Middle vesical artery 
 
 Deep epigastric artery 
 Pubic branch of epi- 
 gastric artery 
 Common femoral artery 
 
 Long saphenons vein 
 Pectineus muscle 
 
 Obturator artery 
 
 Adductor magnus 
 
 Internal circumflex artery 
 
 Adductor brevis 
 
 OBTURATOR NERVE (ant. branch) 
 
 Profunda artery 
 
 Adductor longus, hooked aside 
 
 Superficial femoral artery and vein . 
 
 Oracilis muscle 
 Lower part of sartorius 
 
 Psoas muscle 
 Ilio-lumbar artery 
 
 EXTERNAL CUTA- 
 NEOUS NERVE 
 
 Iliacus muscle 
 
 GE. \ITO-CRURAL 
 NER VE 
 
 ANTERIOR CRU- 
 RAL NERVE 
 
 Deep circumflex iliac 
 
 artery 
 Superficial circumflex 
 
 iliac artery 
 
 A.VTERIOR CRfRAL AT. 
 Gluteal artery and 
 
 Tensor fasciae femoris 
 
 (hooked aside) 
 Glutens mediuB and 
 
 minimus 
 Sartorius muscle 
 MIDDLE CUTA- 
 NEOUS NERVE 
 
 NER VE TO RECTUS 
 
 A'ERVE TO VASTl-S 
 BXTKRXl'S 
 
 External circumflex ar. 
 XERVB TO CRl'REUS 
 Rectus, hooked aside 
 
 /. o.\("; SAPBBNO I 'S 
 NERVE A\I) 
 NERVE TO IMN- 
 TUS INTERNUS 
 
 Vastus internus 
 muscle 
 
 FIG. 223. TUP, FKMORAI. ARTKRY IN SCAKTA'S TKIANCI.I. 
 (From a dissection by W. J. Wai sham in St. Bartholomew's Hospital Museum.) 
 
 5. Burrowing of pus from regions above may point here. 
 
 6. Bloodless amputation at the hip involves this region. 
 
 7. Injuries to the vessels and nerves in the space may occur. 
 
 The triangle- should be studied as having tin- following geometrical parts : (I 
 Roof: skin, superficial and deep fascia.-. (2) Floor: iliacus, psoas, pectineus, and 
 adductor longus. (3) Superior boundary : Poupart's ligament. (4) Internal 
 boundary : adductor longus muscle. (5) Fxternal boundary : the sartorius muscle. 
 (6) The base: the superior boundary. (7) The apex : conjunction of adductor 
 
THIGH AND LEG. 
 
 3 Z 3 
 
 longus and sartorius. Contents : (a) The femoral sheath, formed of the iliac fascia 
 behind the vessels, and the transversalis fascia in front of the same. This sheath 
 contains the femoral artery, vein, and femoral canal. (Fig. 212.) (b) The termina- 
 tion of the longsapJienous vein, (c} The external cutaneous nerve of the thigh, which 
 you will find under the anterior superior iliac spine. (//) The spermatic cord in 
 the male, and its homologue, the round ligament, in the female, both of which 
 you will find under the spine of the pubes. (Fig. 224.) (e) The obturator nerve 
 and vessels. (/) The lesser trocJianter of the femur, giving insertion to the iliacus 
 and psoas magnus muscles ; (^) the anterior crural or femoral nerve and its 
 branches ; (/^) the common femoral artery and vein, bifurcating into the profunda 
 and superficial femoral arteries. In this, as in other regions, the student should 
 become so familiar with structures that he can, by the sense of feel alone, say 
 positively what he touches. I remember well a freshman examined the deep 
 
 Obliquus 
 
 interims 
 
 Aponeurosis 
 of obliquuB 
 
 externus 
 
 Spermatic 
 
 cord 
 
 Origin of 
 cremaster 
 Triangular 
 fascia 
 
 Insertion of 
 cremaster 
 
 Loops of 
 cremaster 
 
 Intercolumnar 
 fibres 
 
 FIG. 224. OULIQUUS EXTERNUS AND FASCIA LATA. 
 
 part of Scarpa's triangle, and feeling the lesser trocJianter of the femur, made a 
 diagnosis of osteo-sarcoma ! 
 
 Poupart 's ligament, or crural arch, is the lower part of the aponeurosis of the ex- 
 ternal oblique muscle of the abdominal wall. (Fig. 224.) It extends from the 
 anterior superior iliac spine to the pubic spine. It is continuous below with the 
 fascia lata. (Fig. 212.) It forms the floor of the inguinal canal, upon which 
 floor rest the spermatic cord and round ligament of the uterus, just before they 
 emerge through the external abdominal ring into Scarpa's triangle. 
 
 Hunter s canal (Fig. 219) (i) extends from the apex of Scarpa's triangle to 
 the aperture in the adductor magnus muscle. (Fig. 222.) In other words, it is a 
 groove linking together the popliteal space and Scarpa's triangle. (2) It is 
 bounded externally by the inner part of the vastus internus muscle ; internally by 
 the front surfaces of the adductor longus and adductor magnus muscles. (3) Its 
 roof is the deep fascia passing across from the adductors to the vastus internus. 
 
 It contains : (i) The superficial femoral artery and vein. The vein lies behind 
 
324 
 
 PRACTICAL ANATOMY. 
 
 the artery, according to the rule governing the relations of veins and arteries 
 below the diaphragm. (2) The long saphenous nerve. Note that this nerve is on 
 the outer side of the artery. (3) The communicating branch to the obturator 
 nerve via the subsartorial plexus. 
 
 Explain the quadriceps femoris. 
 
 This is a collective noun indicating a four-headed muscle, on which depends 
 
 LEVEILLE 0i f.'t* 
 
 FIG. 225. MU.-.CLE; OF THE ANTERIOR ASTECT <>K TIIK I'.ODY. 
 \. Pectoralis major. 2. Its clavicular fasciculus. 3. Fasciculus attached to abdominal aponeurosi 
 4,4. External oblique. 5,5. Serratus magnus. 6,6. Anterior border of latissimus dorsi. 7. De 
 cassation of tendinous fibers of pectorales majores. 8. Ensiform cartilage. 9, 9. Abdominal 
 aponeurosis. IO, IO. Linea alba. II. Umbilicus. 12, 12, 12. Tendinous intersections of rectus 
 abdominis. 13,13. External abdominal ring. 14. Pyramidalis. 15,15. External border of rect 
 abdominis. 16. Sterno-hyoid. 17. Omo-hyoid. 18. Sterno-mastoid. 19. Cervical portion 
 trapezius. 20. Deltoid. 21. Biceps brachialis. 22. Pectineus. 23. Sartorius. 24. Kectus 
 femoris. 25. Tensor vaginre femoris. 
 
 extension of the leg. The individual muscles forming the extensor quadriceps 
 femoris all converge to form one tendon, the ligamentum patellae, which is 
 inserted into the tubercle of the tibia. (Fig. 220.) These muscles, from their 
 diverse origin and extensive attachments t< the- femur and ilium, represent both 
 strength and celerity of motion not an easy combination. The rectus, vastus 
 
THIGH AND LEG. 
 
 325 
 
 externus, vastus interims, and crureus make up the extensor musculature. Trace 
 these muscles to the following origins (from Morris) : 
 
 The Rectus. Origin. Anterior head, from the front of the anterior inferior 
 spine of the ilium ; posterior head, from the upper surface of the rim of the 
 acetabulum just external to the attachment of the capsular ligament. 
 
 Vastus Externus. Origin. (i) The upper half of the anterior intertro- 
 
 Posterior limit of external oblique 
 
 Insertion of 
 external oblique 
 
 Internal oblique 
 
 Tensor vaginas 
 t'emoris 
 
 Rectus femoris 
 
 ARTICULAR PORTION OF 
 COTYLOID CAVITY 
 
 PECTINEAL RIDGE 
 
 Fectineus 
 
 Rectus 
 abdominis 
 Pyramidalis 
 Adductor 
 
 longus 
 
 Adductor 
 
 brevis 
 
 DESCENDING RAMUS 
 OF PUBES 
 
 Graoilis 
 
 Latissirnus dorsi 
 
 CREST OF ILIUM 
 
 SUPERIOR GLUTEAL 
 RIDGE 
 
 OBTURATOR NOTCH 
 Semimembranosus 
 
 Quadratus femoris 
 
 Semitendinosus 
 and bicepa 
 
 _ Adductor magnus 
 
 RAMUS OF ISCHIUM Obturator externus 
 
 FIG. 226. THE LEFT HIP-BONE. (Posterior view.) 
 (Trace out the origin and insertion of muscles and consult this figure.) 
 
 chanteric line and the front of the upper part of the femur along the anterior border 
 of the great trochanter ; (2) a horizontal line, which forms the lower border of the 
 great trochanter ; (3) the outer lip of the gluteal ridge ; (4) the upper half of 
 the outer lip of the linea aspera and the adjacent portion of the shaft of the femur 
 for about one-sixth of an inch ; (5) the external intermuscular septum in the 
 neighbourhood of its attachment to the linea aspera. 
 
 Vastus Interims. Origin. (i) The outer lip of the lower half of the linea 
 
Obturator extcrnus 
 
 Gluteus rnediue 
 
 TUBERCLE OF THE 
 quadratus femoris 
 
 Ligamentum teres 
 
 Capsule 
 
 POSTERIOR INTERTROCHANTERIC LINE 
 
 Faoas 
 
 LESSER TROCHANTER 
 
 Iliacus 
 Peotineus 
 
 Adductor brevis 
 
 INTERVENING SPACE OF THE LINEA ASPERA. 
 Adductor longus 
 
 Vastus internuB 
 
 INNER LIP OF THE LINEA ASPERA 
 
 NUTRIENT FORAMINA 
 
 FOR FEMORAL ARTERY 
 
 INTERNAL CONDYLAR LINE 
 Adductor magnus 
 
 Flantaria 
 Oaatrocnemius 
 
 Anterior crucial ligament 
 INTERCONDYLOID NOTCH 
 
 ADDUCTOR TUBERCLE 
 Gaatrocnemius 
 
 lateral ligament 
 
 EXTERNAL CONOYLE 
 
 INTERNAL CONDYLE 
 
 Posterior crucial ligament 
 
 FIG. 227. Tin I ill IIMIK. (Posterior view.) 
 
 (Study the insertion of the adductor on this figure.) 
 
 326 
 
GREATER TROCHANTER 
 
 SUPERIOR CERVICAL TUBERCLE 
 
 Capsule 
 
 OF THE HIP-JOINT ATTACHED TO THE ANTERIOR 
 INTERTROCHANTERIC LINE 
 
 LESSER TROCHANTER 
 Fsoas 
 
 Pyriformis 
 Obturator internua 
 
 ADDUCTOR TUBERCLE 
 Adductor magnus 
 
 External lateral ligament 
 Fopliteua 
 
 INTERNAL CONDYLE EXTERNAL CONDYLE 
 
 FIG. 228. THE LEFT FMUR. (Anterior view. 
 (Study the origin of the vasti on this figure.) 
 
328 PRACTICAL ANATOMY. 
 
 aspera and its external bifurcation, together with the adjacent external inter- 
 muscular septum ; (2) the lower part of the anterior intertrochanteric line and the 
 spiral line of the femur; (3) the inner lip of the whole length of the linea aspera 
 and its internal bifurcation, together with the adjacent part of the internal inter- 
 muscular septum, and the front of the tendon of the adductor magnus ; (4) the 
 greater part of the front and sides of the femur within the limits formed by the 
 three preceding attachments and the origin of the vastus externus. 
 
 The Physiological Adductors of the Thigh. In figure 222 this group of 
 muscles may be seen. They are four in number. They are supplied by the 
 obturator nerve. They are all ligamentous in action to the hip-joint ; hence the 
 obturator nerve will send a nerve to this joint. They all figure conspicuously in 
 the architecture of Scarpa's triangle and Hunter's canal. Study the origin ot 
 these muscles very carefully on figure 226, and then on the cadaver, as follows : 
 
 The adductor longus arises from the anterior surface of the body of the pubis 
 immediately below the crest and angle. 
 
 The adductor brevis arises from the bo'dy and ramus of the pubis, below and 
 external to the origin of the adductor longus. If the student will study the 
 divergence of the ischio-pubic rami, he will then understand why the origin of 
 the adductor brevis is described as external to that of the adductor longus. 
 
 The adductor magnus arises from the tuber of the ischium, and from the 
 ischio-pubic ramus. (Fig. 226.) Examine the perforations in this muscle for 
 the superficial femoral artery to pass into the popliteal space. 
 
 Name the adductor muscles and give their insertions. (Fig. 227.) 
 
 Adductor longus, inserted into middle lip of linea aspera, middle one-third. 
 
 Adductor brevis, inserted into middle lip of linea aspera, upper one-third. 
 
 Adductor gracilis, inserted into inner surface of tibia, upper one-third. (Fig. 216.) 
 
 Adductor magnus, inserted : (i) Into the back of the femur, in a line beginning 
 at the lower extremity of the linea quadrati, and extending along the inner border 
 of the gluteal ridge and the middle of the linea aspera down to its bifurcation ; 
 
 f t 
 
 (2) into the adductor tubercle on the upper and posterior part of the internal 
 condyle ; (3) into the lower part of the internal intermuscular septum. 
 
 Fascial Septa. Having thoroughly dissected all the muscles on the inner 
 part of the thigh and front part of both leg and thigh, I now desire you to answci 
 these questions : 
 
 1. How many musculatures have you found that is, lioiv many groups 
 muscles acting in unison f 
 
 You say : (i) An extensor group, innervated by an extensor nerve, called an- 
 terior crural or femoral ; (2) a flexor group, on the posterior part of the thigh, 
 innervated by a flexor nerve, called the great sciatic ; (3) an adductor group, on the' 
 inner part of the thigh, innervated by an adductor nerve, called the obturator ; 
 (4) an abductor group, on the outer side of the pelvis, innervated by the superior 
 gluteal, an abductor nerve ; (5) * group OH t lie front of the leg flexors of the tarsus 
 and extensors of the toes supplied by the anterior tibial nerve ; (6) a group on the 
 outer surface of the fibula, supplied by the muscular branches of the musculo-cuta- 
 neous nerve ; (7) two groups of muscles on the posterior part of the /eg, innervated 
 by the internal popliteal nerve, extensors of the tarsus and flexors of the toes. 
 
 2. Are the groups individually separated from eaeli other by septa f 
 
 You answer yes, for you have found a fascial septum between the adductors 
 and extensors ; between the flexors and adductors ; between the anterior and 
 lateral groups below the knee ; between the lateral and posterior groups ; be- 
 tween the superficial and deep groups on the back of the leg. 
 
 3. Arc these intermuscular septa attached to bone f Do they in any manner 
 origin to muscle .' Are they derived from deep fascia f 
 
 You answer the above in the affirmative, 
 
, THIGH AND LEG. 329 
 
 Anatomical transition is never abrupt, but gradual. Compact bone-tissue 
 gradually merges into cancellous ; muscle gradually becomes tendinous ; at 
 muco-cutaneous areas skin and mucous membrane gradually partake of the 
 nature of each other. The transition from extension of the leg to adduction of 
 the thigh would be abrupt. This is moderated by the sartorius muscle, which, 
 in consequence of its dual function, has a double nerve-supply and an indepen- 
 dent fascial sheath. The adductor magnus moderates between flexion and 
 adduction ; hence its dual nerve-supply. 
 
 The Femur (Figs. 227 and 228). Name the points of the femur of impor- 
 tance in practical anatomy. 
 
 The head articulates with the acetabulum. 
 
 The neck joins the head of the bone to the shaft. 
 
 The greater trochanter facilitates axial rotation. 
 
 The lesser trochanter facilitates axial rotation. 
 
 The tereal depression is for the ligamentum teres. 
 
 The digital or trochanteric fossa is for the obturator externus. 
 
 The intertrochanteric lines are anterior and posterior. 
 
 The oblique line of the greater trochanter is for the gluteus medius. 
 
 The anterior intertrochanteric line is for the capsule. 
 
 The tip of the greater trochanter is for the gemelli, pyriformis, obturator ex- 
 ternus. 
 
 The condyles articulate with the tibia and patella. 
 
 The condylar ridges limit laterally the popliteal surface. 
 
 The intercondylar notch lodges the crucial ligaments. 
 
 The patellar facet articulates with the patella. 
 
 The adductor tubercle is for the adductor magnus tendon. 
 
 How and ivJicrc are (lie glntcal muscles inserted / 
 
 They are inserted principally by tendon as follows : The gluteus maximus 
 into the gluteal ridge ; the gluteus medius into the oblique line of the greater 
 trochanter ; the gluteus minimus in the anterior border of the greater tro- 
 chanter. 
 
 What is the third trochanter / 
 
 A name given to the gluteal ridge when this is unusually prominent. Growth 
 is the correlative of function ; where extraordinary function is imposed on any 
 group of muscles, or on any single muscle of a group, the bony insertion point 
 of the muscle will be correspondingly increased in size. Trochanter means a 
 bony eminence for muscular attachment, situated favorably for axial rotation of 
 the limb ; hence the name, third trochanter. 
 
 Describe the line a asp era. 
 
 This may be compared to a tree with (i) a trunk, (2) definite roots, (3) definite 
 branches above. Now, when we speak in general terms of a tree, we have in 
 mind the trunk ; when we speak specifically of this object as a shade-tree, we have 
 in mind the branches ; when we speak specifically of its attachments to the earth, 
 we have in mind the roots of the tree. The linea aspera has a trunk which is in 
 the middle one-third of the femur ; branches which ramify definitely in the upper 
 one-third of the femur; roots which are definitely disposed in the lower one- 
 third of the femur. 
 
 Describe the trunk of the linea aspera. 
 
 It is composed of three lips or ridges, produced by muscular traction ; these 
 lips are called outer, middle, inner. This part of the linea aspera occupies the 
 middle one-third of the shaft of the femur, and forms the posterior border of the 
 same. 
 
 How is the root of the linea aspera disposed f 
 
 The outer lip is continued downward and outward to the condyle of the 
 
330 PRACTICAL ANATOMY. , 
 
 femur as the external condylar ridge. The inner lip is continued downward to 
 the adductor tubercle as the internal condylar ridge. The middle lip is continued 
 downward, and expands to form the popliteal surface of the femur. 
 
 Hou arc the branches of the linen aspera disposed / 
 
 The inner lip continues upward, around and below the lesser trochanter, as 
 the spiral line ; to the lower half of this spiral line is attached the vastus externus ; 
 to the upper, the capsule of the hip-joint. 
 
 The outer lip of the linea aspera continues upward and outward, and ends at 
 the base of the great trochanter in the gluteal ridge for the gluteus maximus. 
 
 The middle lip divides into an inner and an outer division. The inner breaks 
 up into two branches, one for the iliacus, the other for the pectineus muscle, both 
 of which continge the lesser trochanter. The outer division of the middle lip 
 of the linea aspera terminates above as a vertical ridge, midway between the 
 trochanters, as the linea quadrati, for the insertion of the quadratus femoris. 
 
 Describe the attachment of muscles to the three lips of the trunk of the linea 
 aspera. 
 
 To the outer, the short head of the biceps femoris and the vastus externus ; 
 to the inner lip, the vastus internus ; to the middle lip, the adductor brevis, adduc- 
 tor longus, and adductor magnus. 
 
 THE PELVIC OUTLET. 
 
 Locate : (i) The subpubic arch ; (2) the tuberosities of the ischium ; (3) the 
 tip of the coccyx ; (4) the ischio-pubic ramus on each side, and give its com- 
 position ; (5) the spine of the pubes ; (6) the symphysis pubis. 
 
 ' Place the subject in the position shown in figure 229 /. e. } flex the leg on 
 the thigh, the thigh on the abdomen, and abduct the thighs. Now fill the rectum 
 with cotton and sew the margins of the anus together. Do not take your stitches 
 too deeply one-fourth of an inch external to the junction of the skin and 
 mucous membrane is enough. 
 
 Incisions. (i) Cut from the subpubic arch through the skin to the front 
 margin of the anus ; then from the posterior margin of the anus to the tip of 
 the coccyx ; (2) cut from one tuberosity of the ischium to the other ; (3) make 
 a circular incision around the anus just a little outside of the stitches employed 
 in sewing together the margins of the anus ; (4) now begin, and dissect back the 
 four flaps. The greatest care must be taken to keep the skin very thin thin 
 enough to see through. 
 
 You have now removed the skin from the outlet of the pelvis. This space 
 is diamond in shape, and has the following boundaries : Two lines above and two 
 below will outline the space called the pelvic outlet (i) a line from the tuberos- 
 ity of the ischium to the subpubic arch on each side above ; (2) a line from the 
 tip of the coccyx to the tuberosity on each side below. This outlines two 
 triangles with their bases together on an imaginary line from one tuberosity to 
 the other. 
 
 The anterior triangle is called the permeal ; the posterior, the ischio- 
 rectal. Continue removing skin until yon have exposed a space as lar^e as that 
 represented in figure 229. The next step is to introduce a sound into the 
 bladder, and retain it there by means of string tied tightly around the penis near 
 the end. 
 
 A dissection of this region really consists of only two stages: (i) Of the 
 
THIGH AND LEG. 
 
 33 1 
 
 structures seen in figures 229 and 230; (2) of structures seen in figure 233. 
 After having removed the skin, only a little developing is necessary to expose 
 all the structures seen in figures 229 and 230. To give an adequate idea of the 
 subject, study the following to learn what you are expected to find in the first 
 stage of the dissection : 
 
 1. The deep layer of the superficial fascia that you see in figure 230 turned 
 outward and marked Colics' fascia. Notice this is attached to the ischio-pubic 
 ram us and to the triangular ligament, whose cut edge shows in figure 230. This 
 is called the fascia of Colles. 
 
 2. Around the anus you will see a very delicate layer of muscular fibres that 
 
 BUL80-CAVERNOSUS 
 
 Superficial triangular ligament 
 ISCHIO-CAVERN03U8 
 
 
 INFERIOR PUDENDAL NERVE 
 
 .-ri'j-i:i-ir/AL I'KI;I.\\EAL NERVE 
 
 INFERIOR llJEMOHIilfOIUAL NERVE 
 CUTANEOUS BRANCH OF FOURTH SACRAL 
 
 Gluteus maximus 
 
 TUBEROSiTY OF ISCHIUM 
 Great sacro-sciatic ligament 
 Levator ani 
 Superficial transveraua perinaei 
 
 Sphincter aui 
 FIG. 229. THE MALE PERINEUM. (Modified from Hirschfeld and LeveillS.) 
 
 throws the margin of the anus into folds the corrugator cntis ani, a dermal 
 muscle. 
 
 3. In the anterior triangle you see the three large pyramids originating, \\hich 
 come together to form the penis: (i) The bulb in the centre, being the lower 
 part of the corpus spongiosum ; (2) the crura, parts of the corpora cavernosa 
 on each side, in firm connection with the ischio-pnbic rand. 
 
 4. The bulb, covered by a muscle called the accelerator nriwc in the male. 
 Depress the sound and you can make this bulb stand out very prominently. 
 (Fig. 230.) 
 
 5. Tlie cms penis, covered by a muscle called the erector penis ischio-cavern- 
 
33 2 
 
 PRACTICAL ANATOMY. 
 
 osus in the male. Pull the penis upward and from side to side gently, and this 
 will bring the crura and their investing muscles into view. (Fig. 239.) 
 
 6. The external spliineter aid you will see reaching from the tip and sides of 
 the coccyx, surrounding the anus, to the central perineal point. The outer 
 margins of this muscle seem to become lost in a quantity of fatty and connective 
 tissue. 
 
 7. Another muscle, the superficial transversns perilled, lies between the 
 sphincter ani and the erector penis, extending in an oblique direction from the 
 tuberosity of the ischium to the central perineal point. 
 
 8. Tlie central perineal point, or tendinous centre of the perineum, is in the 
 mid-line from side to side and about one inch in front of the anus. As you will 
 
 Superficial perinceal vessels 
 
 Accelerator urinae 
 
 Colles'B fascia, turned back 
 
 Erector penis 
 
 Transverse perinceal vessels 
 Cut edge of triangular 
 
 ligament 
 
 SUPERFICIAL PERIXJEAL 
 NERVE GIVING OFF 
 TRA NS VERSE BRA NCH 
 Pudic vessels 
 
 Inferior hamarrhoidal vessels 
 and nerves 
 
 Glutens maximus 
 hooked back 
 
 Dorsal artery of penis 
 Artery of crus 
 
 Great sciatic ligament 
 Levator ani 
 External sphincter 
 
 FIG. 230. THE ARTERIES OF THE PERINEUM. 
 On the right side Colics' fascia has been turned back to show the superficial vessels. On the left side the 
 superficial vessels have been cut away with the anterior layer of the triangular ligament to show tin- 
 deep vessels. 
 
 demonstrate in your dissection, and as you may see in figure 229, this point is 
 where the following muscles meet: (i) The sphincter ani ; (2) the superficial 
 transversus perinaei ; (3) the accelerator urinae or bulbo-cavernosus. 
 
 9. The levator ani shows well in both figures, but at this stage of the dissec- 
 tion is obscured by (i) the sphincter ani and (2) the large mass of fat in the 
 ischio-rectal fossa. The muscle is seen in figure 230 on each side of the anus. 
 
 10. The space on each side of the anus is the ischio-rectal fossa. It is now 
 full of fat. Figure 230 shows this fat removed and the levator ani muscle 
 divested of the anal fascia. 
 
 1 1. The greater saero-seiatie ligament must now be located. In the figures it 
 is shown cut on one side to expose the internal pudic structures. 
 
 12. Notice the luzmorrhoidal branches t ami the perineal branches of the internal 
 
THIGH AND LEG. 
 
 333 
 
 pudic vessels and nerves ; also the inferior pudendal nerve, a branch of the small 
 sciatic, distributed to the scrotum and side of the thigh. 
 
 Dissection. Locate the greater sacro- sciatic ligament. Cut this ligament and 
 find under the same, in the lesser sacro-sciatic foramen, the main branches of the 
 internal pudic nerve and vessels. You will find two fair-sized branches given off. 
 Tuey will both be found to break up into numerous branches. Now carefully 
 trace these branches through the fat of the iscldo-rectal fossa the one to the 
 anus, the other forward to the perineum. The branch to the anus is the inferior 
 li&morrhoidal ; the other is the superficial perineal. Notice: (i) These branches 
 are both from the internal pudic ; (2) each divides into cutaneous and muscular 
 branches, for the supply of the muscles and the skin in these regions. The 
 arteries follow the nerves and take the same name. The internal pudic nerve 
 now continues in a canal called Alcock's. This nerve pierces the posterior 
 layer of the triangular ligament (Fig. 233), and gives off the following branches : 
 (i) The dorsal nerve of tlie penis ; (2) nerve to the bulb ; (3) nerve to the corpus 
 cavernosum ; (4) superficial perineal. This, the dorsal nerve of the penis, is the 
 largest division of the internal pudic nerve. You will find it on the inner sur- 
 face of the ramus of the ischium. It passes behind the superficial transversus 
 
 Superficial dorsal vein of penis 
 
 /Deep dorsal vein 
 Dorsal artery 
 
 TUNICA ALBUGINEA 
 
 Vessels 
 
 TUNICA ALBUGINEA 
 
 Artery 
 
 Artery 
 URETHRA 
 CORPUS SPONGIOSUM 
 
 FIG. 231. TRANSVERSE SECTION THROUGH THE BODY OK THE PENIS. 
 
 perinaii muscle, gains the deep perineal space, pierces the anterior layer of the 
 deep perineal fascia, and is distributed to the dorsum of the penis. 
 
 Crus Penis (Dissection of] and Its Muscle the Erector Penis, or IscJiio-cavern- 
 OS j {Sf The muscle covers the crus. Cut through the centre of the muscle in 
 the long diameter and turn the two halves aside. Notice its extensive origin : 
 (i) Tuberosity of ischium, (2) ramus of ischium, (3) surface of the crus. Trace 
 the muscle up to its insertion into the sides and under surface of the crus ; also 
 notice its nerves and vessels. Now cut through the thick, strong capsule of the 
 crus in its long diameter, and examine the erectile tissue of its interior. This 
 tissue is the specific element of the crus, and is called, in common with the 
 remainder of the lateral pyramid of the penis, the corpus cavernosum. Observe 
 the strong origin of the crus from the ischio-pubic ramus. 
 
 Dissection of Accelerator Urimc and the Bulb. Depress the sound and make 
 the bulb, covered by the accelerator, stand out full. This muscle, as you see, is 
 in the mid-line, in front of the anus. The muscle being on the stretch, you will 
 now see in the middle a raphe separating the two halves. Now cut, with a very 
 sharp knife, through the center of this raphe and turn the muscle outward, and 
 thus expose the bulb. (Fig. 230.) Trace the muscle and note its insertions : (i) 
 
334 PRACTICAL ANATOMY. 
 
 Tlie lowest fibres into the triangular ligament; (2) the middle, surround the 
 bulb ; (3) tlie upper ones pass out across the corpus spongiosum and are inserted 
 into the dorsum of the penis and pubic bone. Notice, also, the nerve-supply to this 
 muscle from the internal pudic. Now cut through the bulb down to the sound 
 and see (l) the bulbous part of the urethra and (2) the erectile tissue ; the latter 
 is the specific element of the bulb, and, taken with the remaining part of the 
 middle cylinder of the penis, is called the corpus spongiosum. Notice the dense 
 fibrous capsule of the bulb, derived from the outer layer of the triangular liga- 
 ment, upon which the bulb rests. See the nerves and vessels from the internal 
 pudics. 
 
 Dissection of Superficial Transversus Penned. Trace this little muscle from 
 the tuberosity of the ischium to the central point of the perineum, it being inserted 
 between the sphincter ani and the accelerator. Notice the nerve-supply. 
 
 Dissection of the Penis. With the scissors cut through the mid-line of the 
 skin of the scrotum and under part of the penis. Now.carefully remove the integu- 
 ment from the entire organ. As stated above, the penis is composed of three- 
 cylinders, which converge from three different sources. These three cylinders 
 are (i) the two corpora cavernosa and (2) the urethal cylinder or corpus 
 spongiosum, which unite to form a triangular body with three compartments. 
 In transverse section. (Fig. 231.) See, now, that each cylinder has special char- 
 acteristics, (i) The central cylinder, resting on the outer layer of the triangular 
 ligament, begins in the bulb and terminates in an expansion, the glans penis, 
 which receives the conical extremities of the lateral cylinders. (Fig. 232.) (2) 
 The lateral cylinders, the corpora cavernosa, begin in blunt crura from the ischio- 
 pubic ramus, are covered by compressor muscles, erectores penis, and terminate in 
 pointed extremities in the distal expansion of the corpus spongiosum the head of 
 the penis. Observe, also, that each cylinder has common characteristics : (i) a 
 fibrous elastic envelope ; (2) erectile tissue. Lastly, see the middle cylinder 
 traversed from end to end by the urethra. Now cut down on the sound and 
 expose the urethra. (Fig. 232.) 
 
 The urethra is the mucous canal extending from the bladder to the extremity 
 of the glans penis. In its course it pierces the prostate from base to apex, 
 the deep and superficial triangular ligaments with the intervening compressor 
 urethrae muscle, and the whole length of the corpus spongiosum. It may hence 
 be divided into three segments : (i) Prostatic ; (2) membranous (the portion lying 
 in the space between the two transverse triangular ligaments) ; and (3) spongy. 
 (Fig. 232.) 
 
 Having completed the first stage of the dissection of the pelvic outlet, review 
 your work carefully, and see if you have found the following structures : 
 
 1. You removed the skin, learned the boundaries of the pelvic outlet, and 
 classified the same into an anterior or perinea/ portion, and a posterior or isc/iio- 
 rectal portion. 
 
 2. You saw the deep layer of the superficial fascia, Colics' fascia, having 
 two attachments : (i) To the ischio-pubie ramns ; (2) to the triangular ligament. 
 
 3. You located the greater sacro-sciatic ligament, cut the same, and found 
 the main trunk of the internal pudic nerve with its accompanying vessels. In 
 tliis locality you found two nerves given off. One of these you traced through 
 the fat in the ischio-rectal fossa, in many branches, to the corrugator cutis ani 
 and external sphincter ani muscles, and also to the skin covering these muscles ; 
 this was the inferior hicinorrlmida/ nerve. The other you traced, under tin.- name 
 of superficial peri/teal nen>e, to (i) the accelerator, (2) tin- erector penis, (3) 
 the superficial transversus penn;ei, and to the skin covering these muscles. 
 
 4. Then you located the central point of tlie perineum, and learned the muscles 
 meeting there and their nerve-supply as follows: (i) Accelerator urin;e ; (2) 
 
THIGH AND LEG. 
 
 335 
 
 erector penis ; (3) superficial transversus perinaii ; (4) levator ani. Nerve-supply, 
 the internal pudic. 
 
 5. You then located the origin of the three cylinders of which the penis is 
 composed, the central one on the triangular ligament as the bulb, the lateral 
 ones on the ischo-pubic rami as the crura, and you studied the muscles associ- 
 ated with these three cylinders : accelerator urinse and erector penis. 
 
 URETER -4 
 
 Plica uretica 
 
 SECTION OF BLADDER 
 
 INTERNAL URINARY MEATUS 
 
 PROSTATIC SINUS WITH OPENING OF 
 PROSTATIC GLANDS 
 
 SINUS POCULARIS 
 
 FOLLICULAR GLANDS OF DORSAL WALL 
 
 SEPTUM PECTINIFORME 
 
 THIN LAYER OF CORPUS SPONGIOSUM 
 ORIFICE OF COWPER'S GLAND 
 
 Albuginea of corpora cavernoaa 
 
 FOSSA NAVICULARIS 
 
 EXTERNAL URINARY MEATUS 
 
 SECTION OF PROSTATE 
 VERUMONTANUM 
 EJACLTLATORY DUCT 
 PROSTATIC GLANDS 
 
 MEMBRANOUS URETHRA 
 
 SECTION OF CORPUS CAVERNOSUM 
 
 BULBOUS PORTION OF URETHRA 
 
 Mucous membrane 
 
 j/ I(; . 232. THE MALE URETHRA, CLEFT DORSALI.V TO SHOW VENTRAL Mucors WALL. 
 
 6. You examined the three component cylinders of the penis ; saw the 
 general and special characters of each. You saw each cylinder surrounded by a 
 dense tunica albuginea and composed internally of erectile tissue. You saw the 
 central cylinder traversed by a conduit the urethra ; you opened this urethra and 
 studied its interior. In the cuts and in your dissections you studied both the 
 transverse and longitudinal sections of the penis. 
 
336 
 
 PRACTICAL ANATOMY. 
 
 SECOND STAGE IN DISSECTING THE PELVIC OUTLET. 
 
 Dissect the crura from the rami and turn them upward over the pubic bone 
 and fasten them out of your way. Cut the central cylinder the corpus spongi- 
 osum off even with the outer layer of the triangular ligament. Detach the 
 external sphincter ani and the two superficial transverse perineal muscles at the 
 central perineal point. Then your field will look like the leftside of figure 233. 
 
 The triangular ligament (Fig. 233) occupies the space under the pubes. It 
 consists of two layers, superior and inferior, also called superficial and deep tri- 
 angular ligaments, between which are found : (i) The membranous urethra (Fig. 
 232) ; (2) the duct of Cowper's gland perforating the superficial triangular 
 ligament (Fig. 233) and opening into the bulbous urethra (Fig. 232); (3) the 
 dorsal nerves and vessels of the penis perforating the suspensory ligament of the 
 penis and supplying the back of the penis (Fig. 233); (4) the deep transversus 
 perinaei or compressor urethrae, the muscle of Guthrie. (Fig. 234.) 
 
 The above structures are seen on removing the inferior layer of the triangular 
 
 Subpubic ligament with aperture for 
 dorsal vein of the penis 
 
 Apertures for dorsal artery and ( 
 nerve of the penis \ 
 
 Crus penis 
 Aperture for artery of corpus 
 
 cavernosum 
 
 Superficial triangular ligament 
 Ischio-caveruosus, or erector penis 
 Aperture for artery 
 
 to bulb 
 
 TJrethral aperture 
 Aperture for Cow- 
 per's duet 
 Position of bulb 
 
 Apertures for super- 
 ficial perinceal 
 vessels and nerve 
 
 Fascia of Colles, 
 turned backwards 
 
 DORSAL NERVE 
 Anterior layer of triangular 
 
 ligament 
 Dorsal artery of penis 
 
 Deep triangu- 
 lar ligament 
 Artery of carpus 
 cavernosum 
 
 Artery to bulb 
 
 J'n</i<' reins 
 
 * DORSAL NERVE 
 POSITION OF COWPER'S 
 GLAND 
 
 Internal pudic artery 
 
 Posterior border of 
 permaeal ledge 
 (junction of trian- 
 gular ligaments 
 with fascia of 
 (Jolles) 
 
 FIG. 233. DIAGRAM OF THE SUPERFICIAL AND DEEP TRIANGULAR LKJA.MI-N is. 
 
 ligament. (Fig. 233.) Now study the attachments of, and the foramina in, the 
 triangular ligament and compare your work with figure 233. 
 
 You will now dissect the ischio-rectal fossa. You have traced the inferior 
 haemorrhoidal vessels through the fatty mass of this fossa to the rectum and anus. 
 You will now remove the fat and study the geometrical parts of this region. 
 
 'I'lic outer wall \?> formed by the obturator interims muscle and the innominate 
 bone. This muscle is covered by a dense fascia of the same name. This fascia 
 splits to form a canal (Alcock's) in which are the internal pudic vessels and 
 nerve. TIic inner wall of the ischio-rectal fossa is formed by the levator ani and 
 coccygeus muscles. These, as you will see, embrace the rectum and give it sup- 
 port. The levator ani muscle arises from the white line. This line extends from 
 the spine of the ischium to the pubic bone. The obturator fascia delaminutcs at 
 the white line, and gives origin to the levator ani muscle in the split between the 
 upper and lowrr branches into which it divides. The apex, then, of the fossa is 
 at the white line. The boundaries, as you will now see them on your work, of 
 tin- inlet of the fossa are: (i) The external sphincter ani; (2) the superficial 
 transversus perinaei ; (3) the greater sacro-sciatic ligament ; (4) the glutens maxi- 
 inus muscle; (5) the tubers of the ischium. The base of the fossa is the skin 
 
THIGH AND LEG. 
 
 337 
 
 and fasciae covering the inlet. The fossa extends in an upward direction to the 
 pubic bone ; in a backward direction to the sacrum, forming the anterior and 
 posterior recesses of Morris. In liberating pus in this fossa, cut through the base ; 
 then lay your knife aside and continue the operation with a blunt instrument. 
 
 1. Give tlie shape of, and tell ivJiat yon mean by, the pelvic outlet. 
 
 It is lozenge-shaped, and is the space bounded by the pubic arch above, the 
 coccyx below, and the greater sacro-sciatic ligament, tuberosity of the ischium, 
 and ischio-pubic ramus laterally. 
 
 2. Give the subdivisions of this space, and tell zvhere the boundary -line between 
 the two is located. 
 
 A line from tuberosity to tuberosity of the ischium divides the space into an 
 anterior triangle, the perineum, and a posterior triangle, the ischio-rectal fossa. 
 
 P'IG. 234. MUSCLE OF GUTHRIE. 
 I. Bulbo-cavernosus (accelerator urinre) muscle. 
 2. Muscle of Guthrie (transversus perinaei profun- 
 dus). 3. Superficial transverse muscle. 4. Ex- 
 ternal sphincter ani. 5. Levator ani. 
 
 FIG. 235. MUSCLE OF GUTHRIE AND WILSON. 
 
 i. Bulb of urethra. 2, 2. Muscle of Guthrie 
 (transversus perinsei profundus). 3. Muscle of 
 Wilson. 4. Transversus perin<iei superficialis. 
 5. External sphincter ani. 6. Levator ani. 
 
 3. Give the contents of the ischio-rectal fossa. 
 
 It contains the rectum and the fossa on each side of the rectum, called ischio- 
 rectal fossa. 
 
 4. Give the geometrical parts of this fossa and the importance you attach to 
 each part. 
 
 (i) Apex, at the white line, the origin of the levator ani ; (2) base, the skin 
 and fasciae, between anus and tuber of ischium ; (3) outer wall, the obturator 
 internus, Alcock's canal and contents ; (4) inner wall, the levator ani and coccy- 
 geus muscles covered by the anal fascia ; (5) an anterior or pubic recess ; (6) a 
 posterior or sacral recess. 
 
 5. Where is Alcock's canal, how is it found, and what are its contents ? 
 
 It is in the outer wall of the ^chic-rectal fossa, in a delamination of the ob- 
 turator fascia ; it contains the internal pudic vessels and nerve and extends from 
 the lesser sacro-sciatic foramen to the deep triangular ligament. 
 
 6. Name the contents of the ischio-rectal fossa. 
 
 The fossa contains fat and connective tissue, in which are embedded the 
 inferior haemorrhoidal nerves and vessels. On dissection you will see these 
 structures crossing the fossa to supply the rectum. 
 
PRACTICAL ANATOMY. 
 
 7. Xame tlic structures tJiat meet at tlie central point of tJic perineum. 
 
 The accelerator urinae and bulb. The external sphincter ani. The superfi- 
 cial trans versus perinaei. The rectum and labia majora. The triangular liga- 
 ment and labia majora. The fascia of Colles. The superficial perineal space. 
 
 8. What is the importance of the fascia of Colles in extravasation of urine 
 through the bulb ? 
 
 This fascia limits its extension laterally and posteriorly, since it is attached 
 both to the ischio-pubic ramus and lower part of the triangular ligament. 
 
 9. Give the derivation of the superior layer of the triangular ligament. 
 It is a continuation of the obturator fascia. 
 
 i o. Define the anal fascia. 
 
 It is a division of the obturator fascia that covers the under surface of the 
 levator ani muscle. 
 
 I I . Name the several modifications of the pelvic fascia. 
 
 (i) Iliac ; (2) obturator ; (3) white line ; (4) Alcock's canal ; (5) anal fascia ; 
 (6) recto-vesical fascia ; (7) triangular ligament ; (8) pubo-prostatic ligament. 
 
 EJAOULATORY DUCT 
 SINUS POCULARIS 
 
 VERUMONTANUM 
 ORIFICE OF EJACULATORY DUCT 
 
 AMPULLA OF VAS DEFERENS 
 
 UNION OF VESICULA WITH VAS 
 
 EJACULATORY DUCT ENTERING 
 PROSTATIC FISSURE 
 
 PROSTATE 
 
 MEMBRANOUS URETHRA - 
 
 ORIFICE OF SINUS POCULARIS 
 LOWER END OF VERUMONTANUM 
 
 VESICULA SEMINALIS 
 
 FIG. 236. VASA DEKERENTIA AND VESKTI.V. SKMINUIS. (After Sappey.) 
 
 The Base of the Bladder and Seminal Vesicles. Having thoroughly 
 studied the perineum and ischio-rectal fossa, make a dissection to show (i) the 
 membranous urethra, (2) the prostate gland, (3) the lower part of the rectum, 
 (4) the vesiculae seminales, (5) the base of the bladder, in the following manner 
 (turn to Fig. 229) : Cut the external sphincter ani and pull the rectum back- 
 ward and downward over the coccyx. This will put the levator ani on the 
 stretch. Now divide the levator ani near the white line its origin, as you will 
 remember. Now you will see in the mid-line (i) the membranous urethra, with 
 Cowper's gland on each side; (2) the prostate gland, receiving at its central part 
 the ejaculatory duct of the seminal vesicles ( l-'ig. 236); (3) the base of the bladder, 
 occupied by fatty conneetive tissue, in which you will find a remarkable plexus 
 
THIGH AND LEG. 339 
 
 of veins the vesico-prostatic. A small amount of work with the forceps will 
 expose to view all the above structures. 
 
 1 . Describe the prostate gland. 
 
 It is in front of the neck of the bladder, the part resting on the bladder 
 being the base. (Fig. 232.) The posterior surface is on the rectum. The ante- 
 rior surface is behind the symphysis. The apex reaches the triangular ligament. 
 It has three lobes. You will see, between the lateral lobe and the middle lobe, 
 the ejaculatory duct. The prostate is traversed by the urethra and ducts just 
 mentioned. The gland is surrounded by a firm capsule. Its substance is gland- 
 ular and muscular, and not easily torn, as is the spleen. 
 
 2. Describe the vesico-prostatic pie. rns. 
 
 This is now easily shown. It consists of engorged veins which surround the 
 neck and base of the bladder and the prostate, just mentioned. The dorsal vein 
 of the penis passing close under the subpubic arcade discharges into this plexus. 
 (Fig. 233.) Behind this plexus is the haemorrhoidal plexus. The two plexuses 
 communicate very freely. 
 
 3. Give function of vesic nice seminales. (Fig. 236.) 
 
 They act as a reservoir for the semen, just as the gall-bladder is a receptacle 
 for bile. The vas deferens brings semen from the testicle, as the hepatic duct 
 brings bile from the liver. The seminal duct and vas come together to form the 
 excretory duct, just as the cystic and hepatic unite to form the common bile 
 duct. The vas deferens is two feet in length. 
 
 4. Name tlie structures pierced by the male urethra. 
 
 (i) The prostate from base to apex; (2) the deep and superficial triangular 
 ligaments ; (3) the compressor urethrae muscle (Outline's muscle) ; (4) the corpus 
 spongiosum. 
 
 5. Wliat is the average length of the male urethra / 
 
 It is about six and one-half inches long. Its length is increased in senile 
 hypertrophy of the prostate. 
 
 6. Give the length of the pro static urethra and tell zvhat you found in the same. 
 Its length is one and one-fourth inches. In this part of the urethra we found : 
 
 (i) The sinus pocularis, or uterus masculinus, believed to be homologous to the 
 uterus of the female ; (2) the openings for the seminal ejaculatory ducts ; (3) the 
 orifices for the prostatic glands. 
 
 7. Name and locate the dilated parts of the spongy portion of the urethra. 
 
 (i) The pars bulbosa in the bulb, one inch in length ; (2) the fossa navicularis, 
 one inch in length, situated in the glans penis. 
 
 8. Locate the penile angle. 
 
 It is about two inches in front of the external layer ot the triangular ligament. 
 
 9. Describe the blood-supply to and from the penis. 
 
 A distinction must be made between the superficial circulation and the deep : 
 
 (1) The circulation in the retractile or loose covering, or the superficial circu- 
 lation, reaches the penis by (#) the external pudic artery, a branch of the common 
 femoral artery; () the superficial perineal, a branch of the internal pudic; (c] 
 the superficial branch of the dorsal artery of the penis. The blood from this 
 superficial circulation is collected in one or two rather large superficial veins, and 
 conveyed by them to the femoral vein and its large tributary, the long saphenous. 
 
 (2) Blood reaches the penis proper by arteries to the bulb and corpus cavernosum. 
 These vessels are branches of the internal pudic artery. They are given off from 
 this artery in the space between the superficial and deep triangular ligaments. 
 (Fig. 233.) They pierce the superficial triangular ligament preparatory to sup- 
 plying these parts. The dorsal artery of the penis (Fig. 233) also supplies the 
 deep parts of the penis. Blood from this region is returned to the venous circu- 
 lation by two routes : (a) By the dorsal vein of the penis ; (/>) by the veins that 
 
340 PRACTICAL ANATOMY. 
 
 accompany the arteries to the corpora cavernosa and corpus spongiosum. The 
 dorsal vein passes under the pubic arch and is tributary to the vesico-prostatic 
 plexus, at the base and sides of the bladder. The other veins accompany their 
 arteries and become tributary to the internal iliac vein. 
 
 10. Describe the nerve-supply of the penis. 
 
 The erectile bodies receive nerves from the dorsal nerve of the penis ; the 
 superficial perineal and sympathetic filaments from the hypogastric plexus. The 
 skin receives sensory branches from the genito-crural and superficial perineal. 
 
 THE FEMALE PELVIC OUTLET. 
 
 The surgical importance of the female perineum will warrant a thorough 
 consideration of its dissection in this book. The homologies are so striking that 
 some of our best text-books on anatomy seem content to refer the student to the 
 male perineum to gain his conception of the structure of the female peri- 
 neum. To my mind this is a most neglectful practice, since the desideratum is 
 a practical one, involving acquisition of knowledge pending operative procedure, 
 instead of a knowledge in the direct line of morphological research. Would the 
 student be competent to treat the male urethra, who had studied only the clitoris 
 from an anatomical standpoint ? Still, the penis is homologous to the clitoris, and 
 in the male the urethra occupies the entire length of the central cylinder of the 
 penis. Would the student be competent to remove a diseased testicle, whose 
 anatomical knowledge was all in homologies? Again, my experience teaches 
 me that medical students look upon the outlet of the female pelvis not from the 
 standpoint of the morphologist. It requires study and practice to see in the fore- 
 skin, the labia minora ; in the scrotum, the labia majora ; in the accelerator 
 urinae, the sphincter vaginae ; in the bulb of the urethra, the bulb of the vagina ; 
 in the spermatic cord, the round ligament of the uterus ; in the uterus mascu- 
 linus of the prostatic urethra, the uterus of the female ; in the testicle of the 
 male, the ovary of the female. 
 
 The repair of the female perineum is seconded in point of frequency only 
 by extirpation of diseased ovaries and tubes ; in comparison to these operations 
 on the female, seen thousands of times by our students, I would ask our seniors. 
 How many operations on the male perineum have you witnessed ? How many 
 castrations have you been party to ? A student may be expert in introducing* 
 the catheter into the male urethra, but without special knowledge he will be ai 
 ignominious failure when he attempts to perform this operation on the female. A 
 knowledge of the specific anatomy of the female generative organs must In- 
 acquired by dissection ; homological studies are most useful and most necessary 
 adjuncts. 
 
 Examine before making any incisions : 
 
 1. The mons veneris, or mons pubis, the fatty elevation covered with crisp 
 hair, surmounting the pubes. 
 
 2. The vulva is a collective noun by which all the external genitals of the 
 female, except the mons pubis, are designated. 
 
 3. The clitoris is an erectile structure analogous to the penis. Its free 
 extremity is the glans. It has ;i suspensory ligament and erector muscles. On 
 each side it has a cms originating from the ischio-pubic ramus. 
 
 4. The major labia are homologous to the scrotum. They are cleft alon;^ 
 the mid !in-(rima pudendi). They extend from the mons to the tendinous centre 
 
THIGH AND LEG. 341 
 
 of the perineum. They flatten out posteriorly into the smooth covering of the 
 perineum. Their junction here is called posterior commissure. 
 
 5. The minor labia are homologous to the prepuce. They are cutaneous 
 folds. They have neither hair nor fat. In the adult they are concealed by the 
 major labia ; not so in the foetus. They are connected posteriorly by the four- 
 chette. 
 
 6. Examine carefully the vestibule. This is a guide to the meatus urin- 
 arius in using the catheter. It- opens into the meatus and extends from this 
 opening to the clitoris. 
 
 7. The meatus urinarius externus is the distal end of the urethra. It is 
 nearly an inch from the clitoris. Introduce a catheter into the bladder and feel 
 the urethra on the anterior vaginal wall, in the mid-line and 1.5 inch in lerfgth. 
 
 8. The vaginal orifice lies in the mid-line. It is narrowed by the hymen in 
 the virgin, and surrounded by the remains of the hymen in females who have 
 borne children. Its homologue would be artificially produced by a vertical slit 
 
 ISCHIO-HUBIC ARCH 
 
 CRUS CLITORIDIS WITH 
 ISCHIO-CAVERNOSUS 
 
 BULBO-CAVERNOSUS 
 COVERING BULBU3 
 YESTIBULI 
 
 Superficial trian- 
 gular ligament 
 
 GLANS CLITORIDIS 
 WITH PREPUCE 
 
 PARS INTERMEDIALIS 
 Mucous membrane 
 *% of vestibule 
 
 MEATUS URINARIUS 
 
 BULBUS VESTIBULI 
 
 GLAND OF BARTHOLIN 
 
 Sphincter ani 
 
 FIG. 237. DIAGRAMMATIC REPRESENTATION OF THE PERINEAL STRUCTURES IN THE FEMALE. 
 
 through the bulb of the male urethra ; the two parts of the accelerator urinae 
 would then be homologous to the sphincter vaginae, and the erectile tissue of the 
 bulb to the bulbi vestibuli. 
 
 9. "The Hymen " (Fig. 238), says Morris, " has been a subject of much 
 speculation among the learned and unlearned of all ages. Its very existence 
 was at one time denied by many great authorities." Failure to find this in 
 careful examination of several hundred female foetuses and young babes has 
 caused me to ask if it be possible that the hymen is absent in females until the 
 age when other pubal changes occur. The remains of the hymen are called car- 
 uncnlie myrtifonnes. They surround the entrance to the vagina. 
 
 Having located the foregoing nine structures, and thoroughly learned both 
 their function and homologies, where the latter exist, you are now ready to begin a 
 careful dissection of t\\e female pelvic outlet. Remember, there is no difference in 
 the posterior triangular region the ischio-rectal fossa in the sexes. The differ- 
 ences will all be found in the anterior, or perineal region. 
 
342 
 
 PRACTICAL ANATOMY. 
 
 Dissection. Place the subject in the proper lithotomy position, as described 
 previously for dissecting the male perineum. Thoroughly remove all pubic hair. 
 Find the following structures and dissect them in this order : 
 
 1. Tlie clitoris, homologous to the penis. 
 
 2. The labia uiajora, homologous to the scrotum. 
 
 3. The bulbo-cavernosus, homologous to the accelerator. 
 
 4. The bnlbi vcstibuli, homologous to the bulb of the urethra. 
 
 5. The gland of Bartholin, homologous to Cowper's gland. 
 
 6. The sphincter ani, the superficial transversus perincei, and superficial part of 
 the triangular ligament. 
 
 The Clitoris. The clitoris is homologous to the penis. Its size is often 
 underestimated, because the foreskin the labia minora binds it clown so you are 
 
 MONS VENERIS 
 
 GUNS CLITORIDIS 
 
 MEATUS URINARIUS IN 
 VESTI8ULAR SPACE 
 
 CORPUS CLITORIDIS 
 
 LABIUM MAJUS 
 LABIUM MINUS 
 
 HTM EM 
 
 ANUS 
 
 FIG. 238. EXTERNAL GENITALS OF THE VIRGIN, \VITH DIAPIIRACM \ 1 1< HY.MIV (Sappey.) 
 
 able to see only the distal end, called the glans. In the pom's the prq> 
 covers the glans and terminates below in a frenum ; in the clitoris the prepuce 
 terminates in the two elongated labia minora, owing to the vertical cleft of the 
 vaginal orifice. To dissect properly this organ, grasp the glans in the forceps of 
 your left hand, and, with the scissors in your right hand, cut the skin along the 
 dorsum of the clitoris for an inch upward. Then you can see the corona glandi.-' 
 and the glans clitoridis in full view. Next remove carefully the skin from tin- 
 two crura along.the ischio-pubic ramus. You will find these crura covered by a 
 nuiM-lc, the erector clitoridis, homologous to the erector penis. 
 
 Kemove the skin from the labia majora and trace the crescentic muscular fibres 
 of the bulbo-cavernosus muscle around the orifice of the vagina. This is tin- 
 sphincter muscle of the vagina. The transversus perina-i and sphincter ani an 
 
 
THIGH AND LEG. 
 
 343 
 
 the same as in the male. The nerve- and blood-supply are precisely the same. 
 The deep perineal fascia transmits the urethra. It is smaller than in the male, 
 on account of the vagina. (See blood-supply on page 339.) 
 
 The perineal body (Fig. 239) occupies the space between the lower part of 
 the vagina and the rectum. It has a base, covered by skin, and an apex between 
 the termini of its anterior and posterior surfaces. From side to side it extends 
 from tuber to tuber of the ischium. Its posterior surface lies in front of the 
 anterior wall of the rectum ; its anterior surface lies behind the posterior vaginal 
 wall. Into it are attached all the muscles of the central perineal point or tendon : 
 (i) The external sphincter ani ; (2) the superficial transversus perinaei ; (3) the 
 
 VESICAL WALL 
 
 CAVITY OF BLADDER 
 
 Prevesical fat 
 
 Deep transver- 
 BUB perinaei 
 
 LABIUM MAJUS 
 TTnstriped muscular fibre 
 
 URETHRA 
 LABIUM MINUS 
 Unstriped muscular flbre 
 
 ANUS 
 
 Internal sphincter ani 
 Part of external sphincter ani 
 
 Vessels 
 
 RECTUM 
 
 COCCYX 
 
 Eecto-cocey- 
 geal muscle 
 
 POSTERIOR LIP OF OS 
 
 UTERI 
 ANTERIOR LIP 
 
 VAGINA 
 
 External 
 sphincter ani 
 
 Internal 
 sphincter ani 
 
 VAGINAL ORIFICE 
 
 FIG. 239. SECTION OF THE FEMALE PELVIS. (After Henle.) 
 
 This perineal body is strong; it owes its strength to elastic 
 The perineal body is about an inch and a half in length from 
 
 sphincter vaginae, 
 connective tissue, 
 before backward. 
 
 The glands of Bartholin probably represent Cowper's glands in the male, 
 but are more superficially placed. They are two little racemose glands, about 
 a third of an inch long, situated one on each side beneath the lateral wall of the 
 vestibule and behind the bulbi vestibuli. The duct, about three-quarters of an 
 inch in length, opens immediately in front of the vaginal orifice opposite its 
 meridian. 
 
 Locate the vagina by superior and inferior limitations. 
 
344 PRACTICAL ANATOMY. 
 
 It is limited inferiorly by the introitus vaginae at the vestibule, and superiorly 
 by its junction with the cervix uteri. 
 
 Define and locate tlie utcro-vaginal forni.v. 
 
 It is the highest part of the vagina ; a space surrounding that part of the 
 cervix uteri within the vagina, and formed by the reflexion of the vaginal 
 mucous membrane on to the cervix. The vaginal passage extends upward and 
 backward. Its long axis extended would pass through the upper segment of 
 the sacrum. 
 
 What arc tJic anterior relations of the vagina / 
 
 It is in close relation with the urethra and bladder. The ureters open into 
 the posterior wall of the bladder, anterior to the vagina, and about an inch below 
 the lowest part of the cervix uteri. There is a large amount of connective tissue 
 between the anterior wall of the vagina and the bladder and urethra. 
 
 Describe the posterior relations of the vagina. 
 
 The vagina is in relation posteriorly with the rectum. Intervening between 
 the rectum and posterior wall of the vagina from above downward are (i) the 
 peritoneal cul-de-sac of Douglas ; (2) subperitoneal connective tissue ; (3) the 
 perineal body. 
 
 Describe the lateral relations of t/ie vagina. 
 
 (i) The vaginal branch of the uterine artery the uterine being a branch of 
 the internal iliac ; (2) a plexus of veins, lying at the base of the broad ligament 
 of the uterus, communicating with the haemorrhoidal, and tributary to the internal 
 iliac vein. 
 
 Hoiv is the vaginal inlet narrowed ? 
 
 By the action of the sphincter vaginae, the levator ani, and engorgement of 
 the erectile tissue of the inlet, called the bulbi vestibuli. 
 
 Describe the structure of the vaginal wall. 
 
 It is composed of three coats : (i) An outer fibrous coat, a derivative of the 
 recto-vesical fascia. In this coat you will find in some cases a beautiful plexus 
 of veins. (2) A muscular coat, consisting of outer longitudinal fibres and an 
 inner layer of circular fibres. The muscular coat consists of unstriped fibres. 
 (3) A mucous coat, highly elastic, and continuous above with the mucous mem- 
 brane of the uterus, and below with that of the vulva. 
 
 Describe tlie blood-supply of the vagina. 
 
 The arteries, derived from the internal iliac, from the inferior branch of the 
 uterine, and from the external pudic branch of the common femoral artery, lie 
 along the lateral part of the vagina and divide into anterior and posterior branches 
 for the supply of the anterior and posterior surfaces respectively. The veins follow 
 the course of the arteries, form a rich plexus between the inner and middle coats, 
 and finally become tributary to the internal iliac vein. The nerve-supply of the 
 vagina is from the hypogastric plexus, internal pudic nerve, and the fourth 
 sacral. 
 
POSTERIOR PART OF SHOULDER, ARM, FOREARM, AND 
 
 HAND. 
 
 Dissection. Locate (i) the acromion process dx\& spine of the scapula ; (2) 
 the inner and outer Jin in cral condyles ; (3) the olecranon process of the ulna; (4) 
 the head of the radius ; (5) the inferior outer border of the clavicle ; (6) the a.vil- 
 
 Coraco-acromial Pectoralis 
 
 ligament minor Omo-hyoid and the transverse ligament 
 
 AXILLARY BORDER 
 
 Teres major 
 
 SUPERIOR ANGLE 
 
 Rhomboideus 
 minor 
 
 Rhomboideus 
 major 
 
 VERTEBRAL 
 BORDER 
 
 INFERIOR ANGLE 
 
 Latissimus dorsi 
 
 IMC. 240. THE LKI r SCAPULA. (Dorsal surface.) 
 
 lary border of the scapula ; (7) the superior border of the scapula ; (8) the greater 
 and lesser titbcrosities of the hit merits ; (9) the olecranon fossa ; (10) i the Jilnar and 
 radial styloid processes ; (ii) the radio-carpal articulation ; (i 2) the metaearpo- 
 23 345 
 
346 
 
 PRACTICAL ANATOMY. 
 
 plialangeal articulation ; (13) the phalangcal articulations; (14) the clefts of tlic 
 fingers ; (15) the thcnar and JiypotJicnar eminences. 
 
 Incisions. (i) From the acromion process to the end of the middle finger ; 
 (2) from the outer one-third of the clavicle to the acromion process, thence along 
 the scapular spine ; (3) from one condyle to the other. 
 
 Dissection (Figs. 241 and 242). Carefully remove the skin and find the : 
 
 1 . Radial nerve distributed to three and one-half fingers dorsally. 
 
 2. Ulnar dorsal branch to one and one-half fingers dorsally. 
 
 3. External cutaneous, a branch of the musculo-spiral nerve. 
 
 4. Internal cutaneous nerve from the inner cord of the brachial plexus. 
 
 INTERNAL 
 CUTANEOUS OF 
 MUSCULO- 
 SPIRAL 
 
 INTERS A L 
 CUTANEOUS 
 
 PALMAR 
 
 CUTANEOUS OF 
 
 MEDIAN 
 PALMAR 
 
 CUTANEOUS OF 
 
 ULNAR 
 
 SUPRA- 
 
 ACROMfAL 
 
 CIRCUMFLEX 
 
 TWIG OF 
 INTERNAL 
 
 CUTANEOUS 
 
 EXTERNAL 
 CUTANEOUS OF 
 
 MUSCULO- 
 
 SPIRAL 
 
 SUPRA- 
 
 ACROMIAL 
 
 FLEX 
 
 MUSCULO- 
 CUTANEOUS 
 
 EXTERNAL 
 CUTANEOUS 
 
 OF 
 
 MUSCULO- 
 SPIRAL 
 
 MUSCULO- 
 CUTANEOCii 
 
 RADIAL 
 
 PALMAR 
 
 CI'TANEOUS 
 OF RADIAL 
 
 FIG. 241. DISTRIBUTION OK CUTANEOUS NK.KVKS ON TIIK ANTKRIOR AND POSTERIOR ASPECTS 
 
 OF THE SUPERIOR EXTRKMITV. 
 
 5. Lesser internal cutaneous or the nerve of Wrisberg. 
 
 6. Internal cutaneous nerve, a branch of musculo-spiral. 
 
 7. Cutaneous branches of the circumflex nerve to skin of deltoid. 
 
 8. Supraacromial, a descending branch of the cervical plexus. 
 
 9. Intercosto-humeral nerve the lateral cutaneous branch of the second 
 intercostal nerve. 
 
 General directions only can be give 
 (i) Keep close to the skin when you 
 
 Mar- in ally, you will see the name of the nerve, which, having found, take your 
 forceps and search in the superficial fasdu of the region until you find the nerve. 
 
 for doing this cutaneous dissection : 
 remove it. (2) Consult the figures. 
 
SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 347 
 
 (3) Then lift the nerve on your finger and follow the same by dividing the'con- 
 nective tissue in the direction of the branches given off. 
 
 Remember that the circumflex nerve sends its cutaneous branches to the skin 
 over the insertion of the deltoid, according to Hilton's law. (Fig. 241.) The 
 musculo-cutaneous nerve sends a cutaneous branch to supply the skin over the 
 insertion of the supinator longus, according to the same law, since this muscle 
 is one of the forearm flexors and is supplied by the musculo-cutaneous. The 
 
 DORSAL BRANCH 
 OF ULNAR 
 
 BRANCH OF 
 MEDIAN 
 NERVE 
 
 BRANCH OF MUSCULO-SPIRAL 
 
 RADIAL NERYE 
 
 FIG. 242. A DISSECTION OF THE CUTANEOUS NERVES ON THE DORSAL ASPECT OF THE 
 
 HAND AND FINGKRS. (H. St. J. B.) 
 The branches of the median nerve are shown in black. 
 
 distribution of the radial nerve is explained in the same way. You will note that 
 the cutaneous nerves divide into numerous small branches. (Fig. 242.) 
 
 The deep fascia is quite heavy below the elbow, but thin above the elbow. 
 Opposite the wrist it takes the name posterior annular ligament. Notice in figure 
 243 that the muscles all become tendinous before they reach this ligament. 
 Remove the deep fascia as in the figure. "Dorsal fascia" is the name for the 
 deep fascia on the back of the hand. 
 
348 PRACTICAL ANATOMY. 
 
 CLASSIFICATION OF MUSCLES ACCORDING TO FUNCTION. 
 
 ( i. Extensor longus pollicis ; insertion, base of second phalanx. 
 Extensors of the pollux \ 2. Extensor brevis pollicis; insertion, base of first phalanx. 
 
 I 3. Extensor ossis metacarpi pollicis; insertion, base of metacarpal. 
 
 I i. Extensor carpi radialis longior ; insertion, base of second meta- 
 
 Ex tensors of the carfius -: ,- ' j i u L r i. j 
 
 ) 2. Extensor carpi radialis brevior; insertion, baseof third metacarpal. 
 
 v 3. Extensor carpi ulnaris; insertion, base of fifth metacarpal. 
 
 / i. Extensor communis digitorum ; insertion, base of second and 
 
 extensors of t e tgt s -< 2 j xtensor m innni digiti ; insertion, with extensor communis. 
 l. 3. Extensor indicis digiti ; insertion, with extensor communis. 
 
 Extensors of the forear,,. \ [' The triceps ; insertion, into the olecranon process of the ulna. 
 ( 2. The anconeus ; insertion into the oblique line of ulna. 
 
 f i. Brachio-radialis ; insertion, base of styloid of radius. 
 
 Supinator of the radius -, 2. Supinator radii brevis ; insertion, posterior and external surfaces 
 (. of radius. 
 
 Dissection. Trace out the tendons of the three extensors of the thumb by 
 cutting through the deep digital fascia. Take each to its insertion according to 
 insertions given in the classification above. Do not cut the annular ligament. 
 See if two compartments in the annular ligament transmit the three thumb 
 extensors. 
 
 Extensor Carpi Radialis Longior and Brevior. Locate the insertions of 
 these tendons, in the bases of the second and third metacarpal bones respectively 
 on the radial side. Trace the same upward, under the annular ligament, and 
 behind the three extensors of the thumb. (Fig. 243.) 
 
 The extensor communis digitorum sends a tendon to each finger. The 
 tendon of the extensor communis digitorum to the index finger is joined by the 
 tendon of the extensor indicis; the tendon to the little finger, by the tendon of 
 the extensor minimi digiti. Demonstrate this on your dissection. 
 
 The insertion of the extensor tendons is as follows (Fig. 243) : The extensor 
 tendon of each finger divides into three parts, opposite the first phalangeal articu- 
 lation (Fig. 244) ; the middle portion is inserted, just across the joint, into the 
 base of the second phalanx ; the two lateral portions pass the joint, unite on the 
 dorsum of the second phalanx, and pass to the base of the third phalanx, where 
 they are inserted. See whether this muscle and the extensor indicis occupy the 
 same compartment under the annular ligament. Now trace the extensor minimi 
 digiti through a separate compartment in the annular ligament. (Fig. 244.) 
 
 Insertion of the extensor carpi ulnaris : Cut down on its tendon near the base 
 of the fifth metacarpal ; follow the tendon through a groove behind the styloid 
 process of the ulna, and trace it through a separate compartment in the posterior 
 annular ligament. 
 
 Compartments of the Posterior Annular Ligament (Fig. 244). Cut 
 through the annular ligament and find the following compartments and then- 
 contents, and see whether the same are lined by synovial membrane. 
 
 1. For extensor ossis metacarpi pollicis and extensor brevis pollicis. 
 
 2. For extensor carpi radialis longior and brevior. 
 
 3. For extensor longus pollicis. 
 
 4. For extensor communis digitorum and extensor indicis. 
 
 5. For the extensor minimi digiti. 
 
 6. For the extensor carpi ulnaris. 
 
 The Brachio-radialis, or Supinator Radii Longus. Supinate the radius 
 and you will find this muscle, on the radial side, inserted into the- base of the 
 styloid process of the radius. (Fig. 246.) 
 
 
SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 349 
 
 Trace to their origins the radial group of muscles : 
 
 i . Supinator longus, to upper two-thirds of external condylar ridge of the 
 humerus. (Fig. 246.) 
 
 Biceps 
 
 Brachialis anticus 
 Brachio-radialis 
 
 .Extensor carpi radialis lougior 
 
 Extensor communis digitorum 
 
 Extensor carpi radialis brevior 
 
 Extensor ossis metaearpi pollicis 
 
 Extensor brevis polhcid 
 
 Extensor longus pollicis 
 
 Triceps 
 
 Flexor carpi ulnaris 
 
 Extensor carpi ulnaria 
 
 Extensor minimi digiti 
 
 ULNA 
 
 FIG. 243. MUSCLES OF THE RADIAL SIDE AND THE BACK OF THE FOREARM. 
 
 2. Extensor carpi radialis longior, trace to the lower one-third of external 
 condylar ridge of the humerus. 
 
 3. Extensor carpi radialis brevior, to the outer condyle of the humerus. 
 
 To do this properly, begin with the tendon and follow it upward, dividing the 
 
PRACTICAL ANATOMY. 
 
 connective tissue between the muscle and the ones on each side of it. Be careful, 
 in doing this, not to destroy the vessels and nerves ; these structures will become 
 numerous in the region of the elbow. Trace these adjacent muscles also up to 
 
 their origin. 
 
 Extensor oasis metacarpi 
 pollicis 
 
 Extensor carpi ulnaris 
 
 Extensor communis digitorum 
 
 Extensor minimi digit! 
 
 Extensor indicia 
 
 Attachment of extensor 
 oommunis digitorum 
 to second phalanx 
 
 Attachment of extensor 
 communis digitorum 
 to third phalanx 
 
 FIG. 244. TENDONS UPON THE DOKSIM 01 THE HAND. 
 
 Trace the superficial group to origin as follows (Fig. 243) : 
 
 1. Extensor communis digitorum to the outer condyle of the humerus. 
 
 2. Kxtensor minimi digiti to the outer condyle of the humerus. 
 
 3. Kxtensor carpi ulnaris to the outer condyle of the humerus. 
 
 Notice the triple origin of the- extensor carpi ulnaris: (i) The outer con- 
 
SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 351 
 
 dyle ; (2) the posterior surface of the ulna ; (3) posterior border of the ulna, in 
 common with the flexor carpi ulnaris. Dissection of this latter muscle requires 
 care. 
 
 The deep group of muscles and their origin (Figs. 245 and 246) : 
 i. The extensor longus pollicis ulna and interosseous membrane. 
 
 Supinator brevis 
 
 Extensor oasis metacarpi pollicis 
 
 Extensor brevis pollicis 
 Extensor longus pollicis 
 
 Radial extensors 
 
 Flexor carpi uliiaris 
 
 Flexor profundus digitoru 
 
 Extensor indicia 
 
 Extensor oarpi ulnaria 
 
 FIG. 245. THE DEEP LAYER OF THE BACK OF THE FOREARM. 
 
 2. The extensor brevis pollicis radius and interosseous membrane. 
 
 3. The extensor ossis metacarpi pollicis radius interosseous membrane and 
 ulna. 
 
 4. The extensor indicis from the ulna. 
 
 In view of the special importance of the three extensors of the thumb and the 
 
35 2 
 
 PRACTICAL ANATOMY. 
 
 index finger, it is necessary for the student to trace each muscle to its specific 
 origin and insertion according to the following scheme for aiding the memory : 
 
 The extensor indicis (Fig. 245') arises practically from the posterior surface 
 of the lower one-third of the ulna and interosseous membrane. Demonstrate on 
 the cadaver the amount of ulnar surface in the lower third of the bone which 
 
 Triceps 
 
 Lower limit of orbicular ligament 
 
 Grooves for extensor ossis, and extensor 
 primi internodii pollicis 
 
 For extensor carpi radialis longior 
 
 and brevior 
 Extensor secundi interuodii pollicis 
 
 Extensor primi interuodii pollicis 
 
 SUBCUTANEOUS SURFACE 
 
 Extensor ossis metacarpi pollicis 
 
 AN APONEUROSIS IS ATTACHED TO THIS BORDER 
 FROM WHICH THE flexor AND extensor 
 carpi vliaris, AND flexor profundus 
 digitorum ARISE 
 
 Extensor sccundi internodii pollicis 
 
 ULNA 
 Extensor indicis 
 
 Extensor minimi 
 Extensor carpi ulnaris 
 
 Internal lateral ligament 
 
 Extensor communis digitorum Posterior Posterior radio-ulnar ligament 
 and extensor indicis radio-carpal 
 
 ligament 
 
 FIG. 246. THE LEFT ULNA AND RADIUS. (Postero-external view.) 
 
 does not give origin to this muscle. Observe, too, the septal origin of the 
 muscle, between this and the extensor longus pollicis. 
 
 Now consider the origins of the three' extensors of the thumb in reference to : 
 (i) The posterior surface of the radius ; (2) the posterior surface of the ulna ; 
 (3) the posterior surface of the interosseous membrane. Notice, too, you have 
 to deal with a long hone, the ulna ; a short bone, the radius ; and an interosseous 
 
SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 353 
 
 membrane associated with both bones. For purposes of convenience call the 
 extensor ossis metacarpi pollicis the strong muscle. Then say : 
 
 1. The long muscle (the extensor longus pollicis) arises from the posterior 
 surface of the long bone (the ulna) and the interosseous membrane. 
 
 2. The short muscle (the extensor brevis pollicis) arises from the posterior 
 
 Articular branch of superior 
 projundu 
 
 Braehialis anticus 
 Supinator longus, cut 
 
 Common extensor tendon 
 
 Extensor carpi radialis longior 
 and brevior 
 
 Supinator brevis 
 
 Posterior inlerosseous artery 
 
 Extensor osais metacarpi pollicis 
 Supiuator longus, cut 
 
 Extensor primi iuternodii polUcis 
 
 Posterior annular ligament 
 
 Extensor carpi radialis longior 
 
 Radial artery 
 
 Dorsal is pollicis artery 
 
 Extensor secundi internodii 
 
 pollicis 
 
 First dorsal interosseous muscle 
 
 Dorsalis indicis artery 
 
 Pnnceps pollicis artery 
 
 Dorsal digital artery 
 
 Triceps 
 
 Rete over olecranon 
 Inlerosseous recurrent artery 
 
 Ancoueus, cut 
 
 Extensor carpi ulnaris 
 Flexor carpi ulnaris 
 
 Origin of extensor secundi and 
 indicator 
 
 Posterior branch of anterior inlerosseous 
 
 artery 
 Interosseous membrane 
 
 Posterior ulnar carpal artery 
 Extensor carpi radialis brevior 
 Posterior radial carpal artery 
 
 Third dorsal interosseous artery 
 Second dorsal inlerosseous artery 
 Melacarpal or first dorsal interosseous 
 artery 
 
 \J 
 
 Vt_>' 
 
 FIG. 247. THE BACK OF THE FOREARM, WITH THE POSTERIOR INTEROSSEOUS ARTERY AND 
 
 BRANCHES OF THE RADIAL AT THE BACK OF THE WRIST. 
 
 (From a dissection in the Hunterian Museum.) 
 
 surface of the short bone (the radius) and the interosseous membrane. Insertion 
 into the base of the first phalanx. 
 
 3. The strong muscle (the extensor ossis metacarpi pollicis) arises from the 
 posterior surfaces of both the long and short bones (ulna and radius) and the 
 interosseous membrane. Insertion into base of metacarpal bone. 
 
354 
 
 PRACTICAL ANATOMY. 
 
 Observe that the collective origin of the three thumb extensors practically 
 occupies the middle posterior third of ulna, radius, and interosseous membrane. 
 Compare the origins of these muscles as you find them on the cadaver, with the 
 origins as indicated in figure 246. 
 
 Now locate ( i) the posterior interosseous artery. (Fig. 247.) It lies between 
 the superficial and deep groups of muscles. It is a branch of the common inter- 
 osseous branch of the ulnar. Find the space between the oblique ligament and 
 the interosseous membrane, where this vessel appears. Also find where it anasto- 
 moses with the anterior interosseous artery below. Notice that in its course this 
 artery crosses the deep group of muscles, and is attended in a part of its course 
 only by the posterior interosseous nerve. Trace branches from this artery to all 
 the muscles in this locality. This artery is attended by the posterior interosseous 
 nerve in the upper part of its course. Show the exact relation of artery and nerve- 
 on your work. (2) Locate the radial artery in the pulse region of the wrist. You 
 
 FIG. 248. THE DORSAL INTEROSSEI. 
 
 will find it passing under the three extensor muscles of the thumb, where it 
 pierces the first interosseous muscle and disappears into the deep palm. 
 
 The Dorsal Interosseous Muscles (Figs. 247 and 248). Study the muscles 
 and their blood-supply. Find four of these muscles. Notice that they arise by 
 two Heads from the contiguous surfaces of the metacarpal bones. Trace their 
 tendons of insertion to the tendon of the extensor communis digitorum. These 
 muscles (Fig. 248), as you might infer from their insertion, acting alone, are 
 abductors of the fingers. Acting with the palmar interossei and lumbricales, 
 they produce flexion at the metacarpo-phalangeal and extension at the phalan- 
 geal articulations. Acting in this way, they place the fingers in position for hold- 
 ing the pen. These muscles arc all supplied by the ulnar nerve. 
 
 The Supinator Radii Brevis. Detach all the muscles that arise from the 
 outer comlylc : The extensor carpi radialis brevior, the extensor communis 
 digitorum, the extensor minimi digiti. and the extensor carpi ulnaris. Do this 
 
 
SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 355 
 
 in such a way as not to injure the nerve-supply from the musculo-spiral. 
 Now pull these muscles slightly aside and see the supinator brevis. (Fig. 247.) 
 Trace it to the following origins and insertions : 
 
 Origins. (i) Lower and back part of external condyle ; (2) the external lateral 
 ligament of the elbow-joint; (3) the orbicular ligament; (4) the triangular 
 depression below the lesser sigmoid cavity of the ulna, especially along its pos- 
 terior margin, which forms the upper part of the external border of the ulna. 
 
 Insertion. (i) The back of the neck of the radius; (2) the anterior and 
 outer surfaces of the radius above and at the upper border of the oblique line. 
 
 You will now find the posterior interosseous nerve issuing from the lower 
 border of the muscle. This nerve supplies all the muscles in this region except 
 the radial group, which were supplied by the musculo-spiral, before this nerve 
 divided into the radial and posterior interosseous. The radial nerve is a branch 
 of the musculo-spiral. 
 
 The radial nerve perforates the deep fascia, between the extensor carpi 
 radialis and supinator longus about three inches above the carpus. Find where 
 the nerve comes through the deep fascia and trace the same to the dorsum of 
 the hand, and to three and one-half fingers. 
 
 The anconeus (Fig. 245) arises from the back part of the outer condyle. 
 It is inserted into the olecranon and posterior surface of the ulna. Remove this 
 muscle from its attachment, turn the same aside, and see the orbicular ligament 
 of the radius and the elbow-joint. Cut through the orbicular ligament and 
 dislocate the head of the radius. 
 
 The region of the shoulder (Fig. 249) shows : 
 
 1. The deltoid muscle and its nerve-supply, the circumflex. 
 
 2. The supraspinatus muscle (Fig. 251) under the trapezius. (Fig. 250.) 
 
 3. The infraspinatus muscle under the deltoid aponeurosis. 
 
 4. The teres minor muscle, from the axillary border of scapula. 
 
 5. The triceps muscle and its three heads. 
 
 6. The teres major muscle, with the latissimus dorsi. 
 
 7. The triangular space and the dorsalis scapulae artery. 
 
 8. The quadrangular space and its circumflex structures. 
 
 9. The circumflex nerve and vessels in the quadrangular space. 
 
 O. The anterior and posterior circumflex arteries and veins. 
 
 1 1. The musculo-spiral nerve and the superior profunda artery. 
 
 12. The scapular head of tJie triceps muscle between the tereals. 
 
 The circumflex quadrangular space (Fig. 249) is bounded : (i) Externally by 
 the surgical neck of the humerus ; (2) internally by the long or scapular head 
 of the triceps ; (3) superiorly by the teres minor ; (4) inferiorly by the latissimus 
 dorsi and teres major muscles ; (5) contents : posterior circumflex artery, a 
 branch of the axillary, and the circumflex nerve, from the posterior cord of the 
 brachial plexus. 
 
 The triangular space (Fig. 249) is bounded : (i) Externally by the scapular 
 head of the triceps ; (2) superiorly by the teres minor ; (3) inferiorly by the teres 
 major and latissimus dorsi ; (4) contents (Fig. 249) : arteria dorsalis scapulae, a 
 branch of the subscapular artery. 
 
 A second triangular space is bounded (Fig. 249): (i) Externally by the 
 humerus and outer humeral head of triceps ; (2) internally by the scapular head 
 of the triceps ; (3) superiorly by the teres major and latissimus dorsi ; (4) it 
 contains the musculo-spiral nerve, from the posterior cord of the brachial plexus, 
 and the superior profunda artery, a branch of the brachial ; (5) it transmits the 
 external cutaneous branch of musculo-spiral nerve. 
 
 Dissection. The Deltoid Muscle (Fig. 250). Develop the posterior border 
 of this muscle by cutting freely with the scissors the deltoid aponeurosis between 
 
356 
 
 PR A CTJCA L AN A TOM \ '. 
 
 this muscle and the triceps, teres minor, infraspinatus, and trapezius below. 
 Now, with a sharp scalpel cut the scapular origin of the deltoid, along the whole 
 length of the inferior border of the spine and acromion process of the scapula. 
 (Fig. 249.) Turn the muscle forward and see, in a mass of connective tissue 
 and fat, the posterior circumflex artery and circumflex nerve emerging from the 
 quadrangular space. (Fig. 249.) Trace the circumflex nerve to the deltoid and 
 teres minor muscles. Trace the deltoid to its insertion into the deltoid depres- 
 sion on the outer surface of the humerus, middle one-third. Take note of the 
 triangular shape of a number of muscles about the shoulder. 
 
 The Teres Major and Latissimus Dorsi (Figs. 250-253). Divide the 
 connective tissue between these two muscles. Trace them under the scapular 
 
 Infra-spinatus, cut 
 ACROMIAL PROCESS 
 
 Suprascapular artery 
 SPINE OF SCAPULA 
 
 Teres minor 
 
 Superior profunda artery 
 
 Posterior circumflex artery 
 I Deltoid, reflected 
 
 Infra-spinatus, cut 
 
 Teres major 
 Dorsal scapular artery 
 
 Branch of dorsal scapular arferi/ 
 
 '\l-:it\'E TO TERES MINOR 
 
 'SCI Y, O-SPIRA L NER VE 
 Outer head of triceps 
 
 EXTERN. \ I. (TT.i NEO US 
 BKAM'II <,! 
 MUSCULO- 
 
 xriU.il. NERVE 
 
 Lone head of triceps 
 CUTANEOUS BRANCH OF CIRCUMFLEX NERVE, ( IT 
 
 FIG. 249. THE POSTERIOR CIRCUMFLEX ARTERY. 
 (From a dissection by Mr. Horner in the Museum of St. Bartholomew's Hospital.) 
 
 head of the triceps to the humerus. These muscles form the lower bourn 
 of both the quadrangular and triangular spaces. They are inserted as follous : 
 The latissimus dorsi into the bottom of the bicipital groove as high as the lesser 
 tuberosity of the humerus ; the teres major into the inner lip of the bicipital 
 groove for two inches in length. Note that both these tendons are inclosed in a 
 rather tough sheath of connective tissue. 
 
 The teres minor (Figs. 251 and 253) is separated near the humerus from 
 the teivs major by the scapular head of the triceps. Divide the connective 
 tissue between the teres minor and the infraspinatus above and the teres major 
 below. (Fig. 250.) The teres minor arises from the axillary border of the 
 scapula. It is synergistic in its action to the deltoid and derives its nerve-supply 
 from the same circumflex nerve. It is inserted into the lowest facet of the 
 
SHOULDER, ARM, FOREARM, II AA r D. POSTERIOR PART. 357 
 
 Triceps 
 
 Teres minor 
 Infraspinatus 
 
 Teres major 
 
 Rhomboideus major 
 
 Peotoralis major 
 
 Oluteus medius 
 
 Gluteus maximus 
 
 V\<;. 250. FIRST LAYER OF THE MUSCLES OF THE BACK. 
 
358 
 
 PRACTICAL ANATOMY. 
 
 greater tuberosity of the humerus. (Fig. 253.) Demonstrate the quadrangular 
 and triangular spaces according to the outline given in the preceding pages. 
 (Fig. 251.) 
 
 The Infraspinatus (Fig. 251). Now cut this muscle at its insertion into 
 the middle facet of the greater tuberosity ; turn the same backward, taking care 
 not to injure the capsule of the shoulder-joint and the vessels and nerves that 
 enter under the surface of the muscle. This muscle arises from the outer two- 
 thirds of the infraspinous fossa. (Fig. 252.) It is covered by a dense layer of 
 
 Supra-spinatua 
 
 Infra-spinatua 
 Teres minor 
 
 Teres major 
 
 Long head of triceps 
 
 Outer bead of triceps 
 
 Inner bead of triceps 
 
 FIG. 251. BACK VIEW OK THE SCAPULAR MUSCLES AND IK 
 
 deep fascia. The muscle is triangular in shape, and derives its nerve-supply 
 from the infraspinous branch of the suprascapular nerve. 
 
 The supraspinatus muscle (I ig. 251) arises from the outer two-thirds of 
 the fossa of the >ame name and also from the dense aponcurosis covering the 
 muscle. It is inserted into the upper facet 'f the greater tuberosity of the 
 humerus. It is covered (i) by a dense fascia of the same name ; (2) by the 
 trape/.ius muscle, which is inserted into the upper lip of the scapular spine. (Fig. 
 250.) Kxpose this supraspinatus muscle by cutting the insertion of the trape/ius. 
 Then you may trace the supraspinatus under the acromion process to its inser- 
 
SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 359 
 
 tion. Cut this muscle at its insertion, turn it back (Fig. 254), and find the 
 vessels and nerves the suprascapular that supply this region. 
 
 The suprascapular artery and nerve will come into view as you turn aside 
 the supraspinatus muscle. (Figs. 249254.) The nerve you will trace through 
 the suprascapular foramen under the transverse ligament. (Fig. 252.) The artery 
 crosses the transverse ligament. (Fig. 252.) Each structure divides into supra- 
 spinous and infraspinous branches. Trace these vessels and nerves out to their 
 respective localities of distribution. (Fig. 254.) 
 
 The anastomosis between the suprascapular artery and the dorsal branch of 
 the subscapular takes place in the infraspinous fossa, on the bone. Find this. 
 (Fig. 249.) Anastomosis about the shoulder includes the following arteries, 
 which you may now demonstrate. (Fig. 254) : Circumflex, subscapular, dorsalis 
 
 Transverse ligament 
 
 Conoid ligament 
 
 Acromio-clavicular 
 ligament 
 
 Tendon of infra- 
 spinatus and tares 
 minor 
 
 Inferior transverse 
 or spino-glenoid 
 ligament 
 Capsule of shoulder 
 
 FIG. 252. POSTERIOR VIEW OF THE SHOULDER-JOINT, SHOWING ALSO THE ACROMIO- 
 CLAVICULAR JOINT AND THE PROPER LIGAMENTS OK THE SCAPULA. 
 
 scapulae, suprascapular, posterior scapular artery, a continuation of the trans- 
 versalis colli, a branch of the thyroid axis of the subclavian. 
 
 The triceps muscle (Fig. 253) has three heads. The longer scapular 
 head you will now very carefully trace to the axillary border of the scapula, 
 immediately below the glenoid fossa. As you have already observed, this head 
 assists in forming boundaries for the quadrangular space and also for the two 
 triangular spaces. The whole posterior surface of the humerus is occupied by 
 the inner and outer heads of the triceps muscle, and the musculo-spiral groove. 
 
 Dissection. Locate the musculo-spiral nerve and the superior profuncla 
 artery in the second triangle. (Fig. 249.) Now the nerve will pass between the 
 bone and muscle. Cut the muscle in a line corresponding to the course of the 
 nerve, until you come to a point two inches above the outer condyle. The mus- 
 cular mass attached to the posterior surface of the humerus above the groove, in 
 
3 6 
 
 PR A CTICAL ANA TOM 3 . 
 
 which you now see the musculo-spiral nerve, is called the external, or long 
 humeral head of the triceps ; the mass below the musculo-spiral groove is called 
 the internal or short humeral head. Trace the triceps muscle to its insertion, 
 into the olecranon process of the ulna. Cut the insertion of the triceps and 
 study the capsule of the elbow-joint and the olecranon fossa. 
 
 FIG. 253. TRICEPS BRACHIALIS, POSTERIOR A.SI>KCT. 
 
 I. Long, middle, or scapular head. 2. Its tendon of origin from scapula. 3. External, or long humeral 
 head. 4. Internal, or short humeral head. 5. Common tendon. 6. Attachment to olecranon. 
 7. Anconeus. 8, 8. Upper portion of deltoid, posterior half removed. 9. Lower portion. 
 10. Supraspinatus. II. Infraspinatus. 12. Teres minor, middle portion removed. 13. Insertion 
 of teres minor into humerus. 14. Teres major. 15. Upper extremity of latissimus dorsi. 16. Supi- 
 nator longus. 17. Extensor carpi radialis longior. 18. Extensor carpi ulnaris. 19. Flexor ca: 
 ulnaris. 
 
 
 * 
 
 Nei~i>e-supply to the Triceps. As you dissect between the two humeral heads 
 of the triceps, notice the large number of branches given off to the muscle from 
 the musculo-spiral nerve, a branch of the posterior cord of the brachial plexus. 
 
 1. J /<>:,' many origins /ins tin deltoid muscle / 
 
 Two ; one from the lower lip of the scapular spine and acromion, another from 
 the outer one-third of the clavicle. (Fig. 252.) 
 
 2. Tlie origin of (lie deltoid, tlicn, may be said to correspond to tlie insertion oj 
 muscle f 
 
 To the insertion of the trape/itis, since this muscle is inserted into the uppei 
 
SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 361 
 
 lip of the scapular spine and acromion, and into the posterior outer one-third 
 of the clavicle. (Fig. 252.) 
 
 3. Describe the circumflex nerrc. 
 
 It is a branch of the posterior cord of the brachial plexus. (Fig. 42.) It 
 passes through the circumflex quadrangular space, to the back of the shoulder. 
 It gives muscular branches to the deltoid and teres minor muscles, and cutaneous 
 branches to the skin covering the insertion of these muscles and articular 
 branches to the shoulder-joint. (Hilton's la\v.) 
 
 Supra-spinatua Suprasca/mlar artery 
 
 Posterior scapular artery | | Infra-spinatus 
 
 Hhomboideus minor / 
 
 Levator anguli scapulae 
 
 Triceps, cut 
 
 Deltoid, insertion 
 Deltoid 
 
 Trapezius 
 Rhomboideus major 
 
 Terea major muscles 
 
 Deltoid muscle 
 / 
 Triceps 
 
 Teres major, insertion 
 Dorsalis scapulae artery Posterior circumflex artery 
 
 FIG. 254. THE DORSAL SCAPULAR ARTERY. 
 (From a dissection in the Museum of the Royal College of Surgeons.) 
 
 4. Describe the suprascapular nerve. 
 
 A branch of the upper trunk of the brachial plexus. (Fig. 42.) It passes 
 through the constant suprascapular foramen. It gives muscular branches to 
 (i) the supraspinatus, (2) the infraspinatus, and articular branches from each 
 muscular branch, to the shoulder-joint. (Hilton's law.) 
 
 5. Describe the muscnlo-spiral nerve. 
 
 It is a branch of the posterior cord of the brachial plexus. (Fig. 42.) It 
 may be found on the floor of the second triangular space. (Fig. 249.) It passes 
 between the two humeral heads of the triceps in the musculo-spiral groove of the 
 humerus. It lies between the brachialis anticus and brachio-radialis muscles in the 
 lower third of the arm. It gives muscular branches to the triceps and anconeus 
 24 
 
362 PRACTICAL ANATOMY. 
 
 and to all the muscles in the radial region, and also to all the muscles on the pos- 
 terior part of the foramen. Its cutaneous branches are as follows : (i) Radial, to 
 the integument of the ball of the thumb and to three and one-half ringers dorsally, 
 as far as the base of the distal phalanx (Fig. 242) ; (2) internal cutaneous branches 
 to the skin on the inner and posterior part of the arm ; (3) external cutaneous 
 branches to the skin on the outer and front part of the arm. (Fig. 241.) The 
 articular branch to the shoulder is sometimes taken with the circumflex. The 
 posterior nerve-cord is composed of both the circumflex and musculo-spiral and 
 other branches. 
 
 6. Name tJic muscles arising from the external condylar ridge. 
 The brachio-radialis and extensor carpi radialis longior. 
 
 7. Give the origin, course, and distribution of the posterior interosseons nerve. 
 A branch of the musculo-spiral ; it passes between the upper and deep layers 
 
 of the supinator brevis muscle. It lies between the deep and superficial groups 
 of posterior forearm muscles, which it supplies. Note that the musculo-spiral 
 nerve gives off branches to the radial group of muscles prior to its division into 
 the radial and posterior interosseous. Demonstrate this on your dissection. 
 
 If you have not already done so, review you dissection of the musculo- 
 spiral nerve and show that the branches that supply the humeral heads of the 
 triceps muscle are given off at the back of the humerus ; that branches are given 
 off in the axilla to the scapular head. This nerve sometimes accompanies the 
 ulnar nerve as a long slim branch, known as the ulnar collateral. 
 
 8. Describe tlie dorsal inter ossei muscles. 
 
 They are four in number. They are supplied by the ulnar nerve. They 
 have origin from the contiguous sides of the metacarpal bones. (Fig. 248.) 
 Their single independent action is abduction of the fingers, which is always 
 associated physiologically with supination of the radius. Their synergistic action 
 is with the palmar interossei and lumbricales to produce metacarpo-phalangeal 
 flexion, and extension of the second and third phalanges. They are inserted 
 into the bases of three fingers, as shown in figure 248. 
 
 1. Describe tJie median nerve. 
 
 It arises by two heads an outer and an inner from the outer and inner 
 cords of the brachial plexus respectively. (Fig. 42.) It accompanies the axillary 
 artery and its prolongation, the brachial, to the elbow. It gets into the forearm 
 by passing between the condylar and coronoid heads of the pronator radii tores 
 muscle. It gives off no branches to the flexor muscles of the forearm. It is, in 
 rare cases, fused with the musculo-cutaneous nerve. It is said to give off two 
 articular branches to the elbow-joint. It supplies all the muscles on the anterior 
 surface of the forearm, except the flexor carpi ulnaris, and one-half of the flexor 
 profundus digitorum. It supplies three and one-half fingers with sensation. 
 In the hand it supplies the two radial lumbricales and all the muscles of the 
 thenar eminence, except the adductor pollicis and one head of the flexor brevis 
 pollicis. It is accompanied by an artery below the elbow. Sometimes this artery 
 is as large as the radial. It passes under the anterior annular ligament. In the 
 forearm the median nerve lies in the sheath of the flexor sublimis digitorum, on 
 the posterior surface of this muscle. The digital branches of this nerve supply 
 the finger-joints. 
 
 2. Describe tlic itlnar nerrc. 
 
 It is a branch of the inner cord of the brachial plexus. It is attended by the 
 inferior profunda artery above the elbow, and by the ulnar below. It gains the 
 forearm by passing between the two heads olecranon and condylar of the 
 flexor carpi ulnaris. It supplies the flexor carpi ulnaris, and the ulnar half of 
 the flexor profundus digitorum. It supplies one and one-half fingers dorsally 
 and paltnarly. It supplies in the hand all the muscles not innervated by the 
 
SHOULDER, ARM, FOREARM, HAND. POSTERIOR PART. 363 
 
 median nerve. It gives articular branches to the elbow and wrist, and all subse- 
 quent joints moved by the muscles which it supplies. Demonstrate the dorsal 
 ulnar cutaneous nerve. (Fig. 242.) 
 
 3 . Describe the musculo-spiral nerve. 
 
 It is a branch of the posterior cord of the brachial plexus. (Fig. 42.) It is 
 found between the two humeral heads of the triceps muscle in the musculo-spiral 
 groove with the superior profunda artery. In the lower one-third of the arm it 
 lies between the brachialis anticus and supinator longus. In this place it gives off 
 branches to the radial group of muscles the supinator radii longus, the exten- 
 sor carpi radialis longior and brevior. It divides then into the radial and poste- 
 rior interosseous. The posterior interosseous passes through the supinator 
 b re vis and then supplies the muscles on the posterior part of the forearm. The 
 radial branch becomes cutaneous by piercing the deep fascia in the lower one- 
 third of the forearm, between the supinator longus and the extensor carpi 
 radialis. In the hand the nerve supplies the ball of the thumb and adjacent three 
 and one-half fingers dorsally. (Fig. 242.) The musculo-spiral nerve gives off two 
 cutaneous branches to the skin over the insertion of the triceps and anconeus. 
 
 4. Describe the musculo-cutaneous nerve. 
 
 This is a branch of the outer cord of the brachial plexus. (Fig. 42.) It per- 
 forates, as a rule, the coraco-brachial muscle, and gains the intermuscular space 
 between the biceps and brachialis anticus. It supplies the coraco-brachial and the 
 flexor muscles of the forearm, the biceps, brachialis anticus, and supinator longus ; 
 the cutaneous part is distributed to the skin over the insertion of these muscles. 
 
 5. Describe the circumflex nerve. 
 
 It is a branch of the posterior cord of the brachial plexus. (Fig. 42.) It passes 
 through the quadrangular space to the back of the shoulder with the posterior 
 circumflex artery. (Fig. 249.) It supplies the deltoid and teres minor muscles. 
 It gives two articular branches to the shoulder-joint and cutaneous branches to 
 the skin over the insertion of the deltoid and teres minor muscles. 
 
 6. Name the important regions of geometrical parts in the upper extremity. 
 (i) The radial groove ; (2) the ulnar groove ; (3) the cubital fossa; (4) the 
 
 brachial groove ; (5) the axilla ; (6) the quadrangular space (7) the first tri- 
 angular space ; (8) the second triangular space. 
 
 7. Give t/ic special names for deep fascia in the tipper extremity. 
 
 (i) Anterior annular ligament; (2) posterior annular ligament ; (3) dorsal 
 fascia ; (4) palmar fascia ; (5) ligamenta vaginales ; (6) bicipital fascia ; (7) axillary 
 fascia; (8) clavi-pectoral fascia; (9) costo-coracoid ligament; (10) pectoral apo- 
 neurosis ; (11) deltoid aponeurosis ; (12) supraspinous fascia ; (13) infraspinous 
 fascia ; (14) superior transverse scapular ligament ; (i 5) inferior transverse scapu- 
 lar ligament. (Fig. 252.) 
 
 8. What structures did you find under the anterior annular ligament at the 
 carpus ? 
 
 (i) The flexor sublimis digitorum ; (2) the flexor profundus digitorum ; (3) 
 the flexor longus pollicis ; (4) the median nerve and its artery. 
 
 9. Give boundaries of the radial groove, and its contents. 
 
 On the radial side is the supinator longus muscle ; on the ulnar side, in the 
 upper third, the pronator radii teres ; in the remainder of its course, the flexor 
 carpi radialis. In front of the artery the skin and fasciae form the roof of the 
 radial groove. Behind the artery, from above, are : (i) The biceps ; (2) supinator 
 brevis ; (3) pronator radii teres ; (4) flexor sublimis digitorum ; (5) flexor longus 
 pollicis ; (6) pronator quadratus ; (7) a small part of the lower end of the radius. 
 The radial groove contains the radial artery and its vena; comites. 
 
 10. Give boundaries and contents of the ulnar groove. 
 
 The ulnar groove contains the ulnar artery and its venae comites. The artery 
 
3 6 4 
 
 PRACTICAL ANATOMY. 
 
 is a branch of the brachial artery, being given off from this vessel in the cubital 
 fossa. The groove is limited on the ulnar side by the flexor carpi ulnaris, this 
 muscle being the guide to the artery in the lower two-thirds of its forearm course ; 
 on the radial side by the flexor sublimis digitorum ; behind by the brachiali.s 
 anticus, the flexor profundus digitorum, and the pronator quadratus. The ulnar 
 artery is covered in the lower two-thirds by the skin and fasciae. In its course 
 from the cubital fossa to the ulnar groove proper, the artery passes behind all the 
 muscles that originate from the inner condyle of the hurherus, except the flexor 
 carpi ulnaris. On entering the groove proper the artery is joined by the ulnar 
 nerve. 
 
 1 1. Give boundaries of the cubital fossa, and tell what you found in this fossa. 
 
 Externally, is the supinator longus muscle ; internally, the pronator radii teres ; 
 above, an imaginary line passing through the humeral condyles. The roof is 
 formed by the skin and fasciae. The floor is formed by the brachialis anticus and 
 supinator brevis, containing between its superficial layers the posterior inter- 
 osseous nerve. The fossa contains the tendon of the biceps and bicipital tuber - 
 osity ; the median nerve ; the brachial artery, dividing into the radial and ulnar 
 arteries ; the musculo-spiral nerve, dividing into the radial and posterior inter- 
 osseous nerves ; the cutaneous branch of the musculo-cutaneous nerve ; the 
 median cephalic and median basilic veins. 
 
 The student should now review the scheme of the brachial plexus on page 
 77, et seq. 
 
POSTERIOR PART OF LOWER EXTREMITY. 
 
 Dissection. Locate greater trochanter, sacrum, coccyx, tuber of ischium, 
 crest of. ilium, inner and' outer hamstrings, head of fibula, neck of fibula, os calcis, 
 inner and outer malleoli. 
 
 Incisions. (i) From centre of crest of ilium to centre of the os calcis ; (2) 
 from greater trochanter to coccyx ; (3) from internal to external condyle ; 
 (4) from inner malleolus to outer malleolus. Cut deeply enough to permit the 
 edges of the skin to separate one-half of an inch with ease. In removing the 
 skin from any area, cut closely enough that light may shine through the skin. 
 The thing you see now having removed the skin is the superficial fascia. It 
 contains the following structures in a variable amount of fat (Fig. 255) : 
 
 Cutaneous or sensory nerves in figure 255. 
 
 1 . TIic twelfth or last thoracic nerve below the twelfth rib. 
 
 2 . The iliac brancJi of the ilio-liypogastric nerve. 
 
 3 . Posterior branches of the lumbar and sacral nerves. 
 
 4. The external cutaneous nerve of the lumbar plexus. 
 
 5. Tlie small sciatic of the sacral plexus. 
 
 6. The cutaneous branch of the obturator nerve. 
 
 7. Twigs from the long or internal saphenous. 
 
 8. The short saphenous, formed, as you see in figure 255, by the communicans 
 tibialis and communicans fibularis, branches of internal and external popliteal 
 respectively. 
 
 9. The short saphenous vein, with the nerve described in the preceding para- 
 graph. This vein comes from the outer end of the dorsal arch of the foot, runs 
 behind the outer malleolus of the fibula, passes up the mid-line of the leg, 
 between the two heads of the gastrocnemius muscle, pierces the deep popliteal 
 fascia, and opens into the popliteal vein. 
 
 Describe the twelfth thoracic nerve. 
 
 It is seen giving (i) a cutaneous branch to the anterior part of the gluteal 
 region ; (2) a cutaneous branch to the anterior part of the abdominal walls as low 
 as the hypogastric region. The nerve lies below the last rib, with the first lumbar 
 artery. It crosses the quadratus lumborum muscle, and its muscular branches 
 are distributed like the other abdominal intercostals. 
 
 Describe the ilio- hypogastric nerve. 
 
 This is a branch of the lumbar plexus, being given off from the first lumbar 
 with the ilio-inguinal nerve. The iliac branch supplies the integument of the 
 front part of the gluteal region. The hypogastric branch pierces the aponeurosis 
 of the external oblique muscle one inch above the external abdominal ring, and 
 supplies the skin in this region. 
 
 Observe that the posterior branches of the lumbar and sacral nerves supply 
 the skin over the glutens maximus muscle. 
 
 Remember, the external cutaneous branch of the lumbar plexus supplies the 
 skin covering the vastus externus, and may be considered a dismembered branch 
 of the anterior crural nerve, according to Hilton's law. 
 
 365 
 
366 PRACTICAL ANATOMY. 
 
 The small sciatic nerve supplies the skin covering the flexor muscles of the 
 leg. It may be regarded as the dismembered branch of the great sciatic nerve. 
 The long pudendal branch of this nerve crosses the tuber ischii and is distributed 
 to the scrotum of the male and its homologue, the labia majora of the female. 
 
 The long saphenons nerve is a branch of the anterior crural, but to carry out 
 the law governing cutaneous distribution, it extends to the inner side of the 
 ankle, to supply the skin over the fullest insertion (periosteal) of the sartorius. 
 
 If you will now clean off all the fat, you will see a rather dense fascia cover- 
 ing the muscles. This is the deep fascia. That part of this fascia that covers 
 the popliteal space is called the popliteal fascia. Now remove the deep fascia 
 and make your muscles look like figure 256, taking pains not to destroy vessels 
 and nerves. 
 
 You have now exposed to view the gluteus mediu's and maximus, biceps, 
 semitendinosus, semi-membranosus, gracilis, sartorius, plantaris, gastrocnemius, 
 and tendo Achillis. 
 
 THE POPLITEAL SPACE 
 
 is a surgical area occupying the lower posterior one-third of the thigh and the 
 upper posterior one-sixth of the tibia. It is diamond in shape. Its floor is 
 formed by the femur, ligament of Winslow, and popliteus muscle. Its roof is 
 formed by the skin, superficial fascia, and deep popliteal fascia. (See above.) The 
 space is bounded (Fig. 256), above the joint, externally by the biceps muscle, 
 internally by the semitendinosus, semi-membranosus, gracilis, and sartorius ; 
 below the joint, externally by the outer head of the gastrocnemius and plantaris 
 muscle, internally by the inner head of the gastrocnemius. The space contains, 
 in a variable amount of fat and connective tissue : 
 
 1. The terminus of the short saphenous vein in the popliteal. 
 
 2. The descending branch of the small sciatic nerve. (Fig. 260.) 
 
 3. The communicating branches to the short saphenous nerve. 
 
 4. The internal popliteal nerve in the centre of the popliteal space. (Fig. 266.) 
 
 5. The external popliteal nerve with the biceps tendon. 
 
 6. The articular branch of the obturator nerve to the knee. 
 
 7. The popliteal artery and vein and their branches. 
 
 In figure 255 note in particular the formation of the short or external 
 saphenous nerve, by the union of two communicating branches, from the inter- 
 nal and external popliteal nerves. There is no constant level at which this union 
 takes place between the communicans tibialis and the communicans fibularis. 
 
 Locate tlie popliteal space. 
 
 It occupies the lower posterior one-third of the thigh and the upper poste- 
 rior one-sixth of the leg ; it extends from the aperture in the adductor magnuj 
 muscle to the lower border of the popliteus muscle. 
 
 dire tlic relation, in tlic centre' of tlie space, of the internal popliteal ncri-c, and 
 tlie popliteal vein an<l artery. (Fig. 261.) 
 
 The nerve is above, the vein in the middle, and the artery below. (Fig. 269.) 
 
 Remember, when we dissect the popliteal space, the subject is face downward, 
 hence the order referred t<> is as follows : having cut through the skin, super- 
 ficial fascia, and deep fascia, called in this region popliteal fascia, the most super- 
 ficial structure seen in the space under the deep fascia is the internal popliteal 
 nerve; the next deep structure immediately under the nerve is the popliteal 
 vein ; the third deep structure is the popliteal artery. This relation of the vein 
 to its artery is in harmony with the rule governing the relation of arteries 
 their veins, above and below the diaphragm. 
 
POSTERIOR PART OF LOWER EXTREMITY. 
 
 3 6 7 
 
 Why this relation of artery and vein ? 
 
 The rule is : Veins are behind their arteries below the diaphragm, and in 
 front of them above the diaphragm where they are not on the same plane. 
 Exception to rule : the renal vessels. 
 
 What can yon say about the internal popliteal nerve ? (Fig. 266.) 
 
 It begins at the bifurcation of the great sciatic, and ends at the lower border 
 of the popliteal space, where its continuation through the leg is called posterior 
 tibial. In its course it throws off these branches : 
 
 i. The communicans tibialis or communicans poplitei. 
 
 LAST 
 THORACIC 
 ILIO-HYPO- 
 GASTRIC 
 
 EXTERNAL 
 
 CUTANEOUS 
 
 EXTERNAL 
 CUTANEOUS 
 
 COMMUNI- 
 CANS 
 FIBULARIS 
 
 SHORT 
 SA PHENOL'S 
 
 POSTERIOR 
 BRANCHES 
 OF LUMBAR 
 NERVES 
 
 POSTERIOR 
 BRANCHES 
 OF SACRAL 
 NER VES 
 
 PERFORATING 
 CUTANSOU8OF 
 
 SECOND AND 
 THIRD SACRAL 
 
 LONS 
 PUDENDAL 
 
 BRANCHES OF 
 SMALL 
 SCIATIC 
 
 OBTURATOR 
 
 POSTERIOR 
 BRANCH OF 
 INTERNAL 
 CUTANEOUS 
 
 CO.VMUNI- 
 CANS 
 TIBIALIS 
 
 TWIGS FROM 
 LONG 
 S A PHENOL'S 
 
 INTERNAL 
 CALCANEAN 
 
 FIG. 255. DISTRIBUTION OF CUTANEOUS NERVES ON THE POSTERIOR ASPECT OF THE 
 
 INFERIOR EXTREMITY. 
 
 2. Three articular branches to the knee-joint. 
 
 3. Muscular branches to the gastrocnemius, soleus, plantaris, popliteus. 
 The articular branches reach the knee-joint how ? 
 
 One goes with the azygos artery, and two accompany the internal articular 
 arteries, superior and inferior. 
 
 Describe the external popliteal nerve. 
 
 It begins at the bifurcation of the great sciatic, is found in the outer side of the 
 popliteal space in the sheath of the biceps muscle. It leaves the space between 
 the biceps and the outer head of the gastrocnemius muscle. It crosses the neck 
 of the fibula, having passed behind the head of this bone, and terminates in the 
 anterior tibial and musculo-cutaneous nerves. In its course it gives off these 
 
3 68 
 
 PR A CTJCAL ANA TOMY. 
 
 Oluteus medius 
 
 Aponeuroeis of eluteus maxjmus 
 
 Vaatua externus 
 
 Gluteua maximus 
 
 Peroneua longui 
 
 Semi-membranoaus 
 
 Semi-tendinosus 
 
 Gracilis 
 
 Tendon of semi-membranosas 
 
 Sartoiiua 
 
 Flexor longus difcitorum 
 
 Tendo Achillii 
 
 KM:. 256. Sri'KKi i. IAI MK.M i K> 01 mi. i:.\< K (i nn '1'iiu.ii AND LEG. 
 
POSTERIOR PART OF LOWER EXTREMITY. 369 
 
 \ 
 
 branches : (i) The communicans fibularis or communicans peronei ; (2) three 
 articular branches to the knee. (Fig. 264.) 
 
 77*6' articular branches reach the joint how ? 
 
 One goes with the anterior tibial recurrent artery. Two accompany the 
 external articular arteries, superior and inferior. Remember, nerve trunks that 
 supply muscles, supply the skin covering the muscles, and the joints the muscles 
 move. 
 
 Describe the popliteal artery. 
 
 It extends from the aperture in the adductor magnus muscle, to the lower 
 border of the popliteus muscle. It is a continuation of the superficial femoral 
 artery. In its course it gives off these branches : (i) Muscular to the borders of 
 the popliteal space ; (2) articular branches, five in number, called superior two 
 (internal and external), inferior two (internal and external), and one called the 
 azygos. These arteries, as above indicated, are all accompanied by articular 
 nerves from the popliteal branches of the great sciatic nerve. 
 
 Short saphenons nerve is iiow formed, and where distributed / 
 
 It is formed by the union of the communicans tibialis and communicans 
 fibularis branches of the internal and external popliteal nerves respectively, and 
 distributed to the posterior part of the leg and to the outer border of the foot. 
 
 /// how many zvays is the scmimcmbranosns muscle inserted? 
 
 In two ways : (i) Tendinously, into the inner tuberosity of the tibia ; (2) apo- 
 neurotically, in (a) ligament of Winslow, (<$) into internal lateral ligament of the 
 knee, (r) into the oblique line of the tibia, as the popliteal aponeurosis. Notice, 
 aponeuroses are named according to the name of the muscle they cover or 
 the surgical area they invest e. g., axillary, masseter, parotid, etc. 
 
 Explain tlie insertion of the gracilis, semitendinosus, and sartorius. 
 
 They are inserted into the upper one-third of the inner surface of the tibia, 
 below the tuberosity ; the gracilis and semitendinosus by tendon, the former one- 
 half inch the higher. The sartorius is inserted by a broad aponeurosis, which 
 completely covers in the insertions of the other two muscles. 
 
 The ] icads of the gastrocnemius differ in origin how / 
 
 The inner head arises above the condyle ; the outer, from the side of the 
 condyle. The latter seems to have been crowded out of place by the plantaris 
 muscle at least let this suggestion aid the memory. 
 
 Geometrical Inventory of the Popliteal Space : 
 
 Roof skin, superficial and deep fasciae. 
 
 Floor femur, ligament of Winslow, popliteus muscle. 
 
 Superior end aperture in the adductor magnus muscle. 
 
 Inferior end oblique line of the posterior surface of the tibia. 
 
 Superior border externally, the biceps muscle. 
 
 Superior border internally, semitendinosus, semimembranosus, gracilis, and 
 sartorius muscles. 
 
 Inferior border internally, inner head of the gastrocnemius. 
 
 Inferior border externally, outer head of the gastrocnemius and plantaris. 
 
 Shape diamond ; resembling two triangles with bases together. 
 
 In the center are seen the internal popliteal nerve and popliteal vessels. 
 
 Outer border the external popliteal nerve is in the sheath of biceps. 
 
370 
 
 PRACTICAL ANATOMY. 
 
 THE GLUTEAL REGION. 
 
 The gluteus maximus muscle (Eig. 256) must now be put on the stretch 
 by rotating the entire limb inward, and at the same time drawing the subject to 
 the edge of the table and slightly lowering the leg. Now, with a sharp scalpel 
 remove the deep fascia from the muscle itself (Fig. 257), and locate the line of 
 differentiation between the gluteus maximus and medius. Theoretically, this is 
 easily done, but practically some experience is necessary to obtain perfect results, 
 since the gluteal aponeurosis continues forward and completely covers the gluteus 
 medius muscle. The gluteus maximus originates : (i) From the aponeurosis of 
 the gluteus medius ; (2) from the lumbar aponeurosis and the greater sacro-sciatic 
 ligament ; (3) from the side of the coccyx ; (4) from the back of the lateral part 
 
 FIG. 257. GLUTEUS MAXIMUS MUSCI.K. 
 I. Gluteus maximus. 2. Its inferior portion. 3. Fibres of attachment to linea aspera. 4. Superior 
 portion. 5, 5. Tendinous fibres of insertion into linea aspera. 6. Upper portion of femoral apo- 
 neurosis. 7. Duplicature of this aponeurosis at superior level of gluteus maximus. 8. Portion of 
 its superficial layer attached to tendinous bands. 9. Lower extremity of tensor vaginae femoris. 
 
 10, IO. Portion of femoral aponeurosis continuous with tendinous fibres of gluteus maximus. 
 
 11. Upper portion of biceps femoris. 12. Upper portion of semitendinosus. 13. Upper portion of 
 seminiembranosus. 14. Gracilis. 
 
 of the lower two segments of the sacrum ; (5) from the posterior one-fifth of the 
 outer lip of the iliac crest ; (6) from the surface of the bone between the crest of 
 the ilium and the superior gluteal ridge. ( l ; ig. 226.) The muscle is inserted 
 into: (i) The ilio-tibial band; (2) into the gluteal ridge of the femur. (Fig. 
 227.) The inferior gluteal nerve, a branch of the sacral plexus, supplies this 
 muscle. 
 
 Cut at its insertion into the deep fascia of the thigh, and into the gluteal 
 ridge of the femur, the gluteus maximus ; turn tin- same back, as seen in figure 
 258. Also cut the insertion of the gluteus medius at the oblique line of the 
 greater trorhanter (Fig. 227), turn same up. and develop your work like 
 figures 258 and 259. Caution! Take the greatest care, in turning the 
 
POSTERIOR PART OF LOWER EXTREMITY. 371 
 
 above muscles back, not to injure the vessels and nerves, upon which both 
 the beauty and benefit of your dissection depend. You have exposed to view 
 now these structures : 
 
 1. The greater sacro-sciatic foramen. (Fig. 226.) 
 
 2. The lesser sacro-sciatic foramen. (Fig. 226.) 
 
 3. Sacro-sciatic ligaments greater and lesser. (Fig. 258.) 
 
 4. The three gluteal muscles. 
 
 5. The pyriformis muscle. 
 
 6. The obturator externus muscle. 
 
 7. The obturator intern us muscle. 
 
 8. The gemelli superior and inferior. 
 
 9. The quadratus femoris muscle. 
 
 10. The superior gluteal nerve and artery. 
 
 1 1. The small sciatic nerve and its branches. 
 
 Sciatic artery 
 
 INFERIOR GLUTEAL NERVE 
 Gluteal artery 
 
 Gluteus 
 
 medius 
 
 Gluteus maximus 
 
 BRANCH TO GLl'- 
 TEUS MAXIMUS 
 
 Tendon of obturator externu3 
 
 Vastus externus Gluteus maximus 
 
 FIG. 258. A DISSECTION OF THE NERVES IN THE GLUTEAL REGION. 
 (The gluteus maximus and glutens medius have been divided near their insertions, and thrown upward.) 
 
 12. The sciatic artery and its branches. 
 
 13. The great sciatic nerve and its relations. 
 
 14. The internal pudic nerve and artery. 
 
 15. The origin of the biceps, semitendinosus, and semimembranosus. 
 
 1 6. The gluteus medius muscle. 
 
 17. The gluteus minimus muscle. 
 
 1 8. The subgluteal bursa over the greater trochanter. 
 
 The gluteus medius arises from the outer lip of the iliac crest for the anterior 
 four-fifths ; from the outer surface of the ilium, between the superior and middle 
 gluteal curved lines (Fig. 226) ; from the dense aponeurosis covering the muscle 
 and separating the same from the gluteus maximus. The muscle is inserted into 
 the oblique line of the greater trochanter of the femur. (Fig. 227.) Nerve-supply 
 is the superior gluteal from the lumbo-sacral cord of the sacral plexus. (Fig. 193.) 
 
 The gluteus minimus arises from the outer surface of the ilium, between the 
 
372 PRACTICAL ANATOMY. 
 
 middle and the inferior curved gluteal lines (Fig. 226), from the capsule of the hip, 
 and is inserted into the anterior border of the greater trochanter. (Fig. 228.) The 
 nerve-supply is from the superior gluteal. (See page 28 1 , Superior Gluteal Nerve.) 
 
 Notice the common origin of the long head of the biceps and semitendin- 
 osus from the tuber of the ischium. (Fig. 226.) See where the semimem- 
 branosus, in its origin from the tuber, crosses the two preceding muscles since 
 it arises from the upper and outer part of the tuberosity. 
 
 Greater Sacro-sciatic Foramen. The notch of the same name (Fig. 226) 
 is converted into this foramen by the lesser sacro-sciatic ligament. It transmits 
 the pyriformis muscle, which divides the foramen into an upper and a lower com- 
 partment. (Fig. 258.) Above the muscle emerge the superior gluteal artery and 
 nerve ; below the muscle, the greater sciatic nerve, the lesser sciatic nerve, the 
 sciatic artery, the internal pudie ncn'c and artery, and the inferior gluteal nerve. 
 
 The pyriformis muscle arises from the anterior surface of the sacrum, be- 
 tween the four upper anterior sacral foramina. The muscle leaves the pelvis by 
 the greater sacro-sciatic foramen, and is inserted into the upper border of the 
 greater trochanter. 
 
 The Gluteal Artery (Fig. 258). The largest branch of the internal iliac; 
 leaves the pelvis by the greater sacro-sciatic foramen, above the pyriformis, 
 divides into a superficial and a deep branch. The former lies between the glutens 
 maximus and medius, and anastomoses with the circumflex iliac branch of the 
 external iliac artery ; the latter the deep branch lies between the gluteus 
 medius and minimus, and anastomoses with the external circumflex artery, a 
 branch of the prof un da. 
 
 The superior gluteal nerve a branch of the lumbo-sacral cord of the sacral 
 plexus accompanies the artery of like name (Fig. 258) and supplies the gluteus 
 medius and minimus and the tensor vaginae femoris. 
 
 The Sciatic Artery (Fig. 258). A branch of the internal iliac. It leaves 
 the pelvis below the pyriformis muscle. It gives branches to the rectum, base 
 of bladder, seminal vesicles, prostate, and all the muscles of the pelvic floor. 
 It sends branches to the muscles on the back of the hip ; one branch, the comes 
 neri'i iscJdadici, to the great sciatic nerve. (Fig. 258.) It anastomoses with the 
 gluteal, the obturator, both circumflex arteries, internal and external, and with 
 the superior perforating artery, a branch of the profunda femoris. 
 
 The Great Sciatic Nerve (Fig. 193). The largest branch of the sacral 
 plexus. Leaves the pelvis below the pyriformis. Lies upon successively the 
 superior gemellus, the internal obturator, the inferior gemellus, the external 
 obturator, the quadratus femoris, and the adductor magnus. (Fig. 258.) It ends 
 in the popliteal space, in the internal and external popliteal nerves. It gives 
 motor branches to the biceps, semitendinosus, semimembranosus, and adductor 
 magnus muscles. It gives to the hip-joint articular branches, which perforate 
 the posterior part of the capsule. 
 
 The Small Sciatic Nerve (Fig. 260). A branch of the sacral plexus. 
 ( Fig. 193.) It leaves the pelvis below the pyriformis muscle, lying behind the 
 greater sciatic nerve. Its branches are cutaneous : ascending, internal, external 
 and descending. The latter passes through the popliteal space to supply the 
 skin over the insertion of the flexors of the leg. (Fig. 255.) The small sciatic 
 is then the great divoircd sensory branch of the great sciatic, carrying out 
 Hilton's law. The internal branches of this nerve are numerous. (Fig. 260.) 
 The short ones supply the skin on the inner side of the thigh ; the longest one 
 of the internal branches is called the inferior pudenda!, or nerve of Sdemmering, 
 and supplies tin- scrotum and labia majora. 
 
 How to find the long pudendal in practical anatomy : It crosses the tendons 
 of the biceps and semitendinosus, on the tuber of the ischium. (Fig. 260.) 
 
POSTERIOR PART OF LOWER EXTREMITY. 
 
 373 
 
 The Inferior Gluteal Nerve. A branch of the sacral plexus. Leaves the 
 pelvis by the greater sacro-sciatic foramen, below the pyriformis, and supplies 
 the gluteus maximus. (Fig. 258.) 
 
 The Lesser Sacro-sciatic Foramen. The notch of the same name is con- 
 
 Gluteus medius 
 
 Pyriformis 
 Gemellus superior 
 
 Gemellus inferior 
 Quadratus femoris 
 
 Gluteua maximus 
 
 Vastus externus 
 
 Biceps 
 
 Crureus 
 
 Short head of biceps 
 Plantaris 
 
 Oastroonemiue 
 
 Obturator interims 
 
 Adductor magnuS 
 
 FIG. 259. THE EXTERNAL ROTATORS AND THE HAMSTRING MUSCLES. 
 
 verted into this foramen by the greater sacro-sciatic ligament. (Fig. 259.) It trans- 
 mits the internal obturator tendon and its nerve, the internal pudic nerve, artery, 
 and vein. (Fig. 258.) The vessels and nerve lie above the tendon. To trace these 
 structures properly, it will be necessary to remove the gluteus maximus from the 
 
374 
 
 PRACTICAL ANATOMY. 
 
 greater sacro-sciatic ligament, and then cut the latter. You \vill then see the 
 internal pudics all entering Alcock's canal. (Fig. 258.) 
 
 Branches and Course of Internal Pudic Nerve. A branch of the sacral 
 plexus. (Fig. 194.) The nerve escapes from the pelvis by the greater sacro- 
 sciatic foramen, crosses the spine of the ischium, enters the pelvis by the lesser 
 sacro-sciatic foramen (Fig. 226), above the tendon of the obturator internus 
 muscle, traverses a delamination of the obturator fascia, called Alcock's canal, in 
 
 Gluteus uiedius 
 
 Gluteus minimus 
 
 Pyriformis, divided 
 
 into two by the 
 
 great sciatic nerve 
 
 GREAT TROCHANTER 
 
 Obturator ezternus 
 
 Quadratus femoris 
 
 Faacial insertion of 
 gluteus mazimus 
 
 Horizontal fibres of 
 adductor inagnus 
 
 Fleshy insertion of 
 gluteus mazimus 
 
 GREAT SACRO-SCIATIC 
 FORAMEN 
 
 GLUTEAL NERVE 
 SUPPLYING POR- 
 TIONS OF GLU- 
 TEUS MEIHUS 
 
 GHuteus mazimus 
 
 Obturator interims. 
 Below is the infe- 
 rior gemellus. The 
 superior gemellus 
 is absent 
 
 BRANCHES Of-' J\- 
 FER10I! 
 DAL NERVE 
 
 GKEAT SCIATIC NEKVE. 
 Under it, oblique fibres of 
 adductor magnus are seeu 
 
 SMA LL SCI A TIC NER VB 
 
 FIG. 260. DEEP DISSECTION OK THI <;i.> n \\ Kuans. 
 (From a preparation in the Hunterian Museum.) 
 
 the outer wall of the ischio-rectal fossa. It gives off the following branches : 
 (l) The inferior liu'inorrlioidal, which crosses the ischio-rectal fossa and supplies 
 the skin around the anus ; (2) the perinea!, which supplies tin- integument of 
 tlu- scrotum and tin- labia majora, the transversus perin;ei, the accelerator urina/, 
 the erector penis, and the compressor urethne, or deep internal transversus perinaei 
 muscle; (3) the dorsal nerre of the penis, which gives off branches to the skin 
 of the penis, and to the corpus cavernosum. 
 
POSTERIOR PART OF LOWER EXTREMITY. 375 
 
 Greater Trochanter (Figs. 227 and 228). Muscles inserted into: (i) The 
 glutens inedins into the oblique line. (2) The glutens minimus into the anterior 
 surface. (3) The obturator externus into the digital fossa. (4) Into the superior 
 border, in the following order, from before backward : the pyrifonnis, the gcuuihis 
 superior, the obturator interims, and the gcmellus inferior. This is the logical 
 order of insertion, since they leave the pelvis in this order. (5) Into the base 
 you will see the vastus externus. (Fig. 228.) Now turn to figures 227 and 
 228 and study these insertions on the bone. In your dissection trace each 
 tendon to its complete insertion. 
 
 Gluteus Maximus Insertion. This muscle is inserted into the gluteal 
 ridge of the femur. This is called the third trochanter when it is very large. 
 It is one of the constituent parts of the linea aspera. Turn to figure 227, and 
 study the linca aspera. (Read page 329 on linea aspera.) 
 
 External Rotators of the Thigh. From the nature of the origin and in- 
 sertion of the pyriformis, gemelli, obturators, and quadratus femoris, they will 
 produce external rotation of the limb, when this is straight that is, when its 
 long axis parallels the long axis of the trunk, as in* the standing or recumbent 
 posture. In the sitting posture, however, when the limb is at right angles to the 
 trunk, they make 'traction parallel to the long axis of the femur, and thereby 
 
 PATELLA 
 
 Synovial membrane 
 
 Capsule - 
 
 FEMUR 
 
 Crucial ligaments ! 
 
 Vt^iHBfitoffiiS! SSMP.W Inner head of gastroccemius 
 
 Biceps ^liisSFQm^SF^r"' Sartorius 
 
 Outer head of gastroonemius - :S ^ ; C!>^ 5&ffiP^<?- Gracilis 
 
 Popliteal artery 
 
 EXTERNAL POPLITEAL NERVE ^^ ^" *^ ^Sem.-membranosus 
 
 Popliteal rein ' 
 INTERNAL POPLITEAL NERVE / Semi-tendinosua 
 
 External saphena vein 
 
 FIG. 261. HORIZONTAL SECTION OF THE KNEE-JOINT. (One-half.) 
 
 become physiological abductors and antagonize the adductor group. The obtura- 
 tor externus remains an external rotator even in the sitting position. Pull the 
 cadaver to the edge of the table, and make this simple demonstration at this 
 stage of your dissection. 
 
 Demonstrate on yourselves external rotation (i) in the standing position ; 
 (2) in the sitting position. In the first case notice the ease with which you may 
 turn the whole limb outward. This act was done with ease because the six 
 external rotators participated in the act. It would be very much more difficult 
 to do if five of these refused to act. This is exactly what occurs when you sit 
 and do external rotation, since five of these muscles cease to be external rotators 
 when exerting traction in the long axis of the limb, as they do in the sitting 
 posture. In the standing position six muscles are exerting traction in the 
 region of the greater trochanter almost at right angles to the long axis of the 
 femur. This makes external rotation easy. In sitting, only one muscle is left 
 to do this work /. e., the external obturator muscle. 
 
 Internal Rotators of the Thigh. The anterior segments of the glutens 
 mcdins and miniums rotate the thigh inward. 
 
 Tendon of Obturator Internus. To show this tendon, carefully separate the 
 
376 
 
 PRACTICAL ANATOMY. 
 
 FIG. 262. SHORT HEAD OF BICEPS AND SEMI- 
 MEMBRANOSUS. 
 
 I. Attachment to ischium of long head of biceps 
 and semitendinosus. 2. Se m i mem bran osus. 3. 
 Its superior tendon. 4. Its inferior tendon. 5. 
 Middle portion of tendon. 6. Its anterior por- 
 tion. 7. Its posterior portion. 8. Section of 
 long head of biceps. 9. Its short head. 10. 
 Its attachment to head of fibula. II, II, II. 
 Adductor magnus. 12, 12. Orifices for passage 
 of perforating arteries and veins. 13. Vastus 
 externus. 14, 14. Insertion of glutens maximus. 
 15. Divided expansion of tendon of this muscle, 
 continuous with the aponeurosis of the vastus 
 
 externus. 16. Attachment <>!" quadratus fenu>ri>. 
 17. Tendon of obturator externus. 18. Attach- 
 ment of glutens medius. 19. Obturator internus. 
 20. Tendon of pyramidalis. 21. (Unions mini- 
 mus. 22. Divided inner ln-ad of gastrocnrmiiis. 
 23. Outer head. 24. Plantaris. 25. Popliteus. 
 26. Soleus. 27. Fibrous ring for artery, vein, 
 and nerve. 
 
 FIG. 263. LONG HEAD OF BICEPS AND SEMI- 
 TENDINOSUS. 
 
 I. Long head of biceps. 2. Common tendon of 
 head of biceps and semitendinosus. 3. Inferior 
 tendon of biceps. 4. Semitendinosus. 5. Its 
 tendon. 6, 6. Its tendinous expansions, con- 
 tinuous with aponeurosis of leg. 7. Semimem- 
 branosus. 8. Its inferior tendon. 9. Gracilis. 
 10. Its tendon. II. Sartorius. 12. Vastus ex- 
 ternus. 13. Femoral attachment of gluteus maxi- 
 nuis. 14. Insertion of gluteus medius. 15. 
 (ilnteus minimus. 16. Tendon of pyriformis. 
 17. Obturator internus. 18. Quadratus femori.-. 
 19. Inner head of gastrocnemius. 20. Outer 
 Ix-ud of gastrornrmius. 21. Plantaris. 22. 
 Popliteal apqneurosis. 
 
POSTERIOR PART OF LOWER EXTREMITY. 377 
 
 muscle above and below from the gemelli. (Fig. 259.) Cut the muscle near its 
 insertion into the greater trochanter, and then trace it back into the pelvis 
 through the lesser sacro-sciatic foramen. Notice the strong converging tendin- 
 ous bands on the under surface of the muscle. Also see the origins of the 
 gemelli from the ischial tuber and spine. (Fig. 226.) 
 
 Reduced to its simplest terms, wliat is a rational pliysiological grouping of tlie 
 muscles primarily concerned in the movements of t lie 1 tip-joint? 
 
 (i) Flexors of the thigh on the abdomen ; (2) extensors of the thigh on the 
 abdomen ; (3) adductors of the thigh on the pelvis ; (4) abductors of the thigh 
 on the pelvis ; (5) internal rotators of the thigh ; (6) external rotators of the 
 thigh. 
 
 Xamc the flexor muscles of tlic tJiigh. 
 
 The iliacus and psoas magnus, inserted into the lesser trochanter of the femur, 
 are, as Morris points out, almost pure flexor muscles. When, however, they 
 deviate from flexion, they are to some extent internal rotators, and not, as is 
 sometimes suggested, external rotators. Nerve-supply, second and third lumbar 
 nerves. 
 
 Hoiv is tlie t/iig/i extended on the pelvis / 
 
 By the action of the gluteus maximus, which is the direct antagonist of the 
 psoas and iliacus. Nerve-supply, the inferior gluteal nerve. 
 
 Name the abductors of tJie hip-joint. 
 
 The tensor vaginae femoris, the gluteus medius, the gluteus minimus. 
 Nerve-supply, superior gluteal. 
 
 Name t/ie adductors of the t/iigh or hip-joint / 
 
 The obturator externus, the adductor longus, the adductor brevis, the adduc- 
 tor magnus, and the adductor gracilis. Nerve-supply, the obturator. 
 
 How is tJie t/iig/t or /tip-joint rotated inward ? 
 
 By the anterior segments of the members of the abductor group of muscles 
 viz., the glutei minimus and medius and the tensor vaginae femoris ; and, in addition, 
 according to Morris, by the ilio-psoas muscle. Nerve-supply, superior gluteal. 
 
 Name the muscles that rotate the thigh outward. 
 
 The pyriformis, the obturator internus, the two gemelli muscles, and 
 the quadratus femoris. These muscles all derive their nerve-supply from the 
 sacral plexus. The obturator externus, although strictly speaking an adductor 
 muscle, becomes an external rotator when the patient is in the sitting posture. 
 
 Now, on figure 263 study the relation of the quadratus femoris, obturator 
 internus, and the gemelli to each other. On figure 262, on which the quadratus 
 and gemelli are removed, study the relation of the obturators to each other. 
 
 BACK PART OF THE LEG. 
 
 Locate the fibrous arch connecting the heads of the gastrocnemius muscle. 
 (Fig. 259.) Notice passing downward into the deep intermuscular space the 
 popliteal artery and vein, in their proper relation to each other, and the internal 
 popliteal nerve. (Fig. 264.) Carefully isolate these structures from each other 
 and from the arch. Then lift the arch upward and cut down between the two 
 heads of the gastrocnemius to the point where this muscle joins the soleus. Also 
 notice between these two muscles the plantaris, with its very long tendon. (Fig. 
 264.) Now cut the gastrocnemius (Fig. 264), and trace each head across the 
 joint to its exact origin on the femur. (Fig. 227.) Notice the difference in origin 
 25 
 
378 
 
 PRACTICAL ANATOMY. 
 
 on the two sides. Also trace the plantaris up to its origin and be sure you find 
 its nerve, a branch of the internal popliteal. (Fig. 264.) 
 
 Locate the fibrous arch of the soleus. (Fig. 264.) See passing under the 
 same the popliteal artery, nerve, and vein, now called posterior tibial, as far clown 
 as the ankle, having passed under the arch of the soleus. Pull the arch up and 
 cut down between the two heads of the soleus. By cutting in the mid-line of 
 these two muscles you preserve the nerve-supply intact, which nerves it is desired 
 you trace out carefully. You will remember the gastrocnemius, plantaris, soleus, 
 and popliteus are supplied by the internal popliteal nerve. (Fig. 264.) Now 
 let your dissection verify the complete distribution of the internal popliteal nerve. 
 Preserve every branch of this nerve. 
 
 On each side of the fibrous arch of the soleus, on the tibia and fibula, you 
 
 Adductor magnua 
 
 Popliteal vein 
 Popliteal artery 
 
 INTERNAL POPLITEAL NERVE 
 
 Vastus interims 
 
 Superior internal articular artery 
 
 Tendon of semi-membranosus 
 
 Inner head of gastrocnemius 
 
 Inferior internal articular arler. 
 Popliteal vein 
 Popliteui 
 
 Tendon of plantaris 
 
 Vastuu eiternus 
 
 GRKA T SCTA TIC SERVE 
 
 Short head of biceps 
 EXTERNAL POPLITEAL SERVE 
 
 Long head of biceps, out 
 Outer head of gastrocnemius 
 
 COMMVNICAN8 PEROXEI XI-:J:VE 
 
 - Soleus 
 
 Qastrocnemius 
 
 External saphenous vein and nerve 
 FIG. 264. DEEP VIEW OF THE POPLITEAL SPACE. (Hirschfeld and Leveille.) 
 
 will see the inner and outer heads of this muscle. (Fig. 208.) Divide them 
 carefully one-half of an inch from their origin, and turn the three muscles of the 
 superficial group aside, and figure 266 will represent what you should have. 
 You now have in view these structures : 
 
 1. The posterior tibial nerve and its branches. (Fig. 266.) 
 
 2. The posterior tibial vessels and their branches. (Fig. 266.) 
 
 3. The remaining origins of the plantaris, soleus, and gastrocnemius, and the 
 popliteus muscle, as seen in figure 265. 
 
 4. The tibialis posticus, an extensor muscle of the tarsus. 
 
 5. The flexor longus digitorum muscle a flexor of the four outer toes. 
 
 6. Tin- flexor longus hallucis muscle a flexor of the great toe. 
 
 ~. The thin, dee]) transverse fascia, or deep intei muscular fascia of the leg, 
 which you will now see covering in all the structures below the popliteus muscle. 
 
 
POSTERIOR PART OF LOWER EXTREMITY. 
 
 379 
 
 If you examine this fascia, you will find it attached internally to the tibia, ex- 
 ternally to the fibula, and above to the oblique line of the tibia. (Fig. 208.) 
 
 Outer head of gastrocnemiue 
 
 Inner head of gastrocuemius 
 
 Biceps 
 
 ' Tendon of semi-metnbrauosus 
 
 PeroneuB longus 1 
 
 Flexor longus hallucis 
 
 PopliteuB 
 
 Tibialia postieus 
 
 Plexor longus digitorum 
 
 Peroneus brevis . 
 
 Tibialis postieus 
 
 . Tendo Aehillis 
 
 FIG. 265. THE DEEP MUSCLES OF THE BACK OF THE LEG. 
 
 It is quite thin, yet strong, and permits the posterior tibial vessels and nerves to 
 be seen through it. 
 
 The Posterior Tibial Nerve (Fig. 266). It begins at the lower border of 
 
3 8o 
 
 PRACTICAL ANATOMY. 
 
 the popliteal muscle ; it is a continuation of the internal popliteal nerve down- 
 ward. It ends under the internal annular ligament (Fig. 266) of the ankle, 
 
 Superior external articular artery 
 
 POPLITEAL NERVE- 
 External lateral ligament 
 
 Inferior external articular artery 
 Popliteus 
 
 Muscular branch to soleus 
 Soleus 
 Anterior tibial artery 
 
 Peroneus longus . 
 Peroneal artery . 
 
 BRANCH OF POSTERIOR TIBIAL . 
 NERVE TO FLEXOR LONGUS 
 HALLUCIS 
 
 Flexor lougus hallucis 
 
 Superior internal articular 
 Popliteal artery 
 
 Posterior ligament of knee 
 
 Azygos articular artery 
 
 SEMI-MEMBRANOSUS 
 
 Inferior internal articular artery 
 
 Muscitlar branch 
 
 Tibialis posticus 
 
 POSTERIOR TIBIAL NERVE 
 
 MUSCULAR BRANCH OF POS- 
 TERIOR TIBIAL NERVE TO 
 FLEXOR LONGUS D1GITORUM 
 
 Flexor longus digitorum 
 
 Posterior tibial artery 
 
 Cutaneous branch of peroneal artery 
 
 Peroneus breviu 
 Continuation of peroneal artery 
 
 OS CALCIS 
 
 Tibialis posticus 
 
 ( 'iiinmi/n imthifj branch 
 Internal annular ligament 
 
 Internal calcaneal artery 
 
 FIG. 266. RELATIONS OK THE I'ori.n KAI. AKTIKY ro BONES AND Mi * US. 
 
 (The Mriu-tiiiv.- M-I-II in tliis li^un- :uv loveu-.l liy ilu- <ln-|> n aii>\ i-rse fascia. Sec P.IL;C ,i7>-.) 
 
 between the internal inallrohis and <>< calcis, h\- di\iding into the internal and 
 external plantar nerves. (Fig. 272.) It accompanies the posterior tibia! v 
 
 first to tin- inner and latrr to tlu- outer side of these vessels. 
 
POSTERIOR PART OF LOWER EXTREMITY. 
 
 POPLITEAL NOTCH 
 
 External fibre-cartilage 
 
 Capsule 
 Posterior crucial ligament 
 
 STYLOID PROCESS 
 Posterior tibio-ftbular ligament 
 
 Tibialis posticus 
 
 Flexor longus hallucis 
 
 FLEXOR SURFACE OF FIBULA 
 
 NUTRIENT FORAMEN 
 
 FIBULA 
 
 Peroneus brevis 
 
 Posterior tibio-flbular ligament 
 
 GROOVE FOR FLEXOR LONGUS HALLUCIS 
 
 External lateral ligament 
 
 (posterior fasciculus) 
 
 External lateral ligament 
 
 (middle fasciculus) 
 
 Internal flbro-cartilage 
 
 Capsule 
 
 Semimembranosus 
 
 Popliteus 
 
 OBLIQUE LINE 
 Soleus 
 
 POSTERIOR SURFACE OF TIBIA 
 
 Flexor lonsus digitorum 
 
 GROOVE FOR TIBIALIS POSTICUS AND 
 FLEXOR LONGUS DIGITORUM 
 
 Internal lateral ligament 
 
 Posterior ligament of ankle-joint 
 
 FIG. 267. THE LEFT TIBIA AND FIISULA. (Posterior view.) 
 
3 82 
 
 PRACTICAL ANATOMY. 
 
 Branches of Posterior Tibial Nerve. (i) An articular branch to the ankle, 
 given off just above the bifurcation of the nerve into the internal and external 
 
 POSTERO-INFERIOR SURFACE OF THE 
 CALCANEUM 
 
 Abductor minimi digit! 
 Abductor oasis metatarsi quiuti 
 
 Accessorius (outer head) 
 
 Plexor brevis hallucis 
 Abductor oasis metatarsi quinti 
 
 Flexor brevis minimi digit! 
 
 Adductor hallucis 
 Third plantar interosseous 
 
 Second plantar interosseous 
 First plantar interosseous 
 
 Flexor brevis minimi digit! 
 
 Abductor brevis minimi 
 digiti 
 
 Third plantar 
 interosseous 
 
 Second plantar 
 luterosseoua 
 
 First plantar interosseous 
 
 Flexor brevis digitorum 
 Flexor lougus digitorum 
 
 Abductor hallucis 
 Flexor brevis digitorum 
 
 Accessorius < inner headi 
 
 Tibialis posticus 
 
 Tibialls anticus 
 Peroneus loneus 
 
 
 .ri^ii-i: Abductor hallueia 
 
 J ~K Flexor brevis halluoi* 
 
 (inner portion) 
 Flexor brevis hallucis 
 
 (outer portion) 
 Adductor hallucis 
 Transversus pedis 
 
 Flexor longus hallucia 
 
 FIG. 268. Tin. I.I.KT FOOT. (Plantar surface. ) 
 (Study the insertion and location of tendons on this and compare your dissection therewith.) 
 
 plantar nerves. (2) A plantar cutaneous nerve, to the heel and inner side of the 
 sole of the foot. (Fig. 272.) (3) Muscular branches to the tibialis posticus, 
 flexor longus hallucis, and flexor longus digitorum musoK-s. ( Fig. 266.) 
 
POSTERIOR PART OF LOWER EXTREMITY. 
 
 383 
 (Fig. 
 
 Two terminal branches the internal and external plantar nerves. 
 272.) 
 
 Branches of the Posterior Tibial Artery. (i) The peroneal artery to the 
 outer side of the leg. (Fig. 266.) (2) A nutrient artery to the tibia, which you 
 will find entering the foramen as far down as the lower end of the oblique line of 
 the tibia, on the ridge separating the origin of the tibialis posticus from the flexor 
 longus digitorum. ( Fig. 208.) Find this artery and recall the rule for the direc- 
 tion of these foramina in the long bones of the extremities : from the knee and 
 
 FIG. 269. MUSCLES OF THE LEG, EXTERNAL ASPECT. 
 
 Tibialis anticus. 2, 2. Tendon of extensor proprius pollicis. 3, 3. Extensor longus digitorum. 4. 
 Its tendons for four last toes. 5. Peroneus tertius. 6. Its attachment to last two metacarpal bones. 
 7. Peroneus longus. 8. Its tendon. 9. Peroneus brevis. 10. Its tendon. II. Outer head of gas- 
 trocnemius. 12, 12. Solens. 13. Tendo Achillis. 14. Extensor brevis digitorum. 15, 15. Ab- 
 ductor minimi digiti. 16. Rectus femoris. 17. Vastus externus. 18. Its inferior fibres. 19. 
 Tendon of biceps femoris. 20. External lateral ligament of knee. 21. Tendon of popliteus. 
 
 toward the elbow. (3) A communicating branch to the peroneal, on the back of 
 the tibia, under the flexor longus hallucis, two inches above the joint. (4) In- 
 ternal calcanean, which communicates with the external calcanean branch of the 
 peroneal artery behind the tendo Achillis. (Fig. 266.) (5) Muscular branches, 
 small and numerous, to the soleus and deep muscles on the back of the leg. 
 (Fig. 266.) 
 
 The Posterior Tibial Canal. For practical purposes we may locate the 
 posterior tibial nerve and its accompanying vessels in a canal, bounded as follows : 
 
384 PRACTICAL ANATOMY. 
 
 Externally, by the flexor longns hallucis ; internally, by the flexor longus digi- 
 torum ; its floor is the tibialis posticus, flexor longus digitorum, tibia, and internal 
 lateral ligament ; its roof, the deep transverse fascia, described in a previous 
 paragraph. 
 
 Deep Muscles of the Leg. (i) Popliteus ; (2) flexor longus hallucis ; (3) 
 flexor longus digitorum ; (4) tibialis posticus. It is necessary now to study 
 the posterior surfaces of the tibia. (Fig. 208.) Notice that the oblique line of 
 the tibia has three lips : (i) An upper one, occupied by the insertion of the pop- 
 liteus muscle ; (2) a middle one, by the soleus ; (3) a lower one, by two muscles 
 the flexor longus digitorum on the outer side of the vertical line, and the tibialis 
 posticus on the inner side. Notice, too, that the posterior surface of the fibula 
 (Fig. 208) is occupied by the origin of two muscles : the outer head of the soleus, 
 the upper one-third, and the flexor longus hallucis, the middle one-third, of this 
 posterior surface. 
 
 What can be said regarding t/ic rather peculiar origin and insertion of the flexor 
 longus digitorum and flexor longus Jiallucis f 
 
 They arise from surfaces of bone above, opposite their insertions, into the 
 phalanges below : The great toe is on the side opposite the fibula ; the four 
 lesser toes are on the side opposite the tibia. Now, the muscle that bends the 
 great toe flexor longus hallucis arises from the posterior surface of the fibula, 
 middle one-third ; likewise, the muscle that bends the four lesser toes the flexor 
 longus digitorum arises from the posterior surface of the tibia, middle one-third. 
 To gain their insertions they cross in the sole of the foot in the second layer ot 
 muscles of this region. (Fig. 270.) 
 
 The flexor longus hallucis traverses four grooves. (Fig. 268.) The flexor 
 longus hallucis needs special mention. It passes through (i) a little groove on 
 the posterior part of the tibia (Fig. 208) ; (2) through a pronounced one on the 
 narrow posterior surface of the astragalus ; (3) through a well-marked groove 
 on the under part of the sustentaculum tali of the os calcis (Fig. 268) ; 
 (4) through a groove between the two sesamoid bones,, in the tendon of the 
 flexor brevis hallucis at the metatarso-phalangeal articulation. This muscle is 
 inserted into the base of the distal phalanx of the great toe. (Fig. 268.) 
 
 Trace the popliteus muscle to its origin. (Fig. 266.) Detach it at the ob- 
 lique line of the tibia, its insertion, and trace it between the outer tuberosity and 
 head of fibula, under the external lateral ligament of the knee and the biceps, to 
 the outer side of the external condyle of the femur. 
 
 Structures under Internal Annular Ligament. From the internal malleo- 
 lus to the os calcis : (i) Tendon of tibialis posticus, next the malleolus ; (2) ten- 
 don of flexor longus digitorum ; (3) a sheath of connective tissue containing the 
 posterior tibial nerve and artery, with a vein on each side of the artery ; (4) behind 
 this sheath, and deeply buried in its three upper grooves, above referred t<>, is 
 the tendon of the flexor longus pollicis. In the dissection of the sole of the foot 
 these several structures will be traced to their various destinations. 
 
 The Peronei Longus and Brevis ( Figs. 266 and 269). These two muscles 
 occupy almost the entire outer surface of the fibula. Commonly, the origin is as 
 follows : the longus from the upper one-third and the brevis from the middle 
 one-third. (Fig. 207.) The muscles are separated in front and behind from 
 adjacent musculatures by intermuscular septa. They pass under the external 
 annular ligament, immediately behind the malleolus, and are inserted : ( f) the 
 brevis into the base of the fifth metatarsal ( Fig. 269) ; (2) the longus pa>ses 
 through a groove on the under surface of the cuboid bone, then through an 
 osseo-aponeurotic canal, to the base of the first metatarsal bone. (Fig. 275.) 
 These muscles are supplied by muscular branches of the nnusculo-cutaneous 
 IH.TVC, a branch of the external popliteal. (Fig. 264.) These muscles, when 
 
POSTERIOR PART OF LOWER EXTREMITY. 
 
 385 
 
 acting together, assist the tibialis posticus in extending the ankle. They are 
 antagonized by the tibialis anticus and peroneus tertius. 
 
 THE SOLE OF THE FOOT. (Fig. 272.) 
 
 The importance of a knowledge of this region can not be overestimated. 
 The large number of important structures in a comparatively small area, com- 
 bined with thick skin, dense plantar fascia, and delicate lumbrical muscles, all taken 
 
 Origin of abductor minimi digiti 
 
 Part of abductor minimi digiti 
 
 Plexor brevis minimi digiti 
 
 Abductor minimi digiti 
 Lumbricales 
 
 Tendon of flexor brevis 
 
 digitorum 
 
 Flexor brevis digitorum 
 
 Abductor hallucis 
 
 Accessorius 
 
 Flexor longus digitorum 
 
 Flexor lougus hallucis 
 Flexor brevia hallucis 
 
 Adductor hallucis 
 Abductor hallucis 
 
 Tendon of flexor brevif- digitorum 
 
 FIG. 270. SECOND LAYER OF THE MUSCLES OF THE SOLE. 
 
 tog-ether make dissection of this area somewhat difficult. A dissection of the 
 
 o 
 
 four layers of muscles alone would be an easy task, but here, as in larger areas 
 of the body, nerves and vessels must be saved. The only general rule I can give 
 you is this : Follow painstakingly as a guide the dissections given in the text, 
 and learn from the figures what you expect to find. Having done this, follow 
 each nerve and vessel out carefully to its distribution. No number of written 
 pages will make an awkward man improve his touch ; hence it is impossible to 
 
3 86 
 
 PRA CT1CAL ANA TOM\ '. 
 
 do more than suggest to the student that he should early learn to cultivate a 
 delicate touch. It requires but little effort with the forceps to divide the delicate 
 connective tissue that surrounds all vessels and nerves, and intervenes between 
 muscles. In the sole of the foot you will find, in this order, from without in- 
 ward, the following structures : 
 
 1. The thickest skin of the body on the sole of the foot. 
 
 2. Superficial fascia, very thick, containing granular fat. 
 
 3. The deep or plantar fascia, with its three divisions. 
 
 Abductor minimi digit! 
 
 Flexor brevis minimi digiti 
 
 Tendon of flexor longus digitorum 
 
 Plexor brevis digitorum 
 
 Abductor liallucis 
 
 Flexor longus hallucie 
 
 Flexor brevis hallucis 
 First lumbricalis 
 
 Tendon of adductor hallucis 
 
 FIG. 271. FIRST LAYER or mi: MTSCLES OF THE SOLS, 
 
 4. The first layer of muscles: The abductor hallucis, the flexor brevis digi- 
 torum, and the abductor minimi digiti. 
 
 5. 'I'lic internal and external plantar nerves and vessels. (Fig- 272.) 
 
 6. The second layer of muscles : The tendon of flexor longus hallucis and a 
 slip of contribution to the flexor longus digitorum ; tendons of the flexor longus 
 digitorum ; the musculus accessorius and lumbricales ; the nerve- and blood- 
 supply to these muscles. 
 
 7. Hie third layer of muscles : Flexor brevis hallucis and its sesamoid bones ; 
 abductor hallucis muscle ; flexor brevis minimi digiti muscle; transversus pedis 
 muscle ; nerve- and blood-sup] >!y to these muscles. 
 
POSTERIOR PART OF LOWER EXTREMITY. 
 
 387 
 
 8. The fourth layer of muscles: Dorsal interossei, four in number; plantar 
 interossei, three in number ; the nerve- and blood-supply to these. (Fig. 275.) 
 
 9. The tendon of tJic pcroncus longus and its sesamoid bone. (Fig. 275.) 
 Incisions. Start at the middle of the os calcis and make one cut through the 
 
 skin to the middle of the great toe ; the other to the middle of the little toe. 
 This V-incision will permit you to find : 
 
 i. The plantar cutaneous nerve, a branch of the posterior tibial nerve. 
 
 Abductor hallueis 
 
 Flexor brevis digitorum 
 
 INTERNAL PLANTAR 
 
 NER YE 
 Internal plantar artery 
 
 BRANCH OF INTER- 
 NAL PLANTAR 
 NERVE TO INNER 
 SIDE OF HALL UX 
 
 Abductor minimi digit! 
 
 External plantar artery 
 
 EXTERNAL PLANTAR 
 
 NER VE 
 
 Ligameuta vaginales 
 
 DIGITAL COLLATERAL 
 BRANCHES OF EX- 
 TERNAL PLANTAR 
 
 DIGITAL COLLATERAL 
 BRANCHES OF INTER. 
 NAL PLANTAR 
 
 FIG. 272. SUPERFICIAL XKKVES IN THE SOLE OF THE FOOT. (Ellis.) 
 (In this dissection the greater part of the plantar fascia has been removed.) 
 
 (Fig. 272.) This is a sensory nerve to the heel, and you will find it in the thick 
 pad of fat in the superficial fascia. Sometimes the granular fat here is three- 
 fourths of an inch thick. 
 
 2. The cutaneous branches of the internal and external plantar vessels 
 and nerves. Exercise now your common sense in removing the skin. 
 
 The superficial fascia contains much fat. The fat found in the palms of the 
 hands, in the soles of the feet of the adult, and all over the body of the child at 
 
88 
 
 PRACTICAL ANATOMY. 
 
 term, is called granular. Remove all this fatty tissue, and notice it becomes less 
 abundant in the hollow of the foot and toward the toes. 
 
 The deep fascia occurs in the sole of the foot, under two names : (i) From 
 the heel to the clefts of the toes it is called plantar fascia ; (2) from the clefts of 
 the toes onward it forms very dense sheaths for the flexor tendons of the toes. 
 These sheaths are called the ligamenta vaginales (ligamentum vaginalis, in the 
 singular). 
 
 Dissection of Plantar Fascia and Ligamenta Vaginales. Having now cut 
 through the dense, deep fascia of the toes, the ligamenta vaginales, you 
 
 External calcanean artery 
 Cutaneous branch of external plantar 
 
 * 
 
 Abductor minimi digit! 
 
 Anastomolic branch 
 External plantar artery 
 
 Pint digital to outer side of 
 
 lillle, lot 
 Lumbrieal muscle 
 
 Second digital 
 Third digital 
 Fourth digital 
 
 Anastomosis about inter- 
 
 phalangeal joint 
 Dorsal branch of collateral 
 digital 
 
 Anastomosis of collateral 
 arteries around matrix of nail 
 and pulp of toe 
 
 Internal calcanean artery 
 
 Cutaneous branch of internal 
 plantar 
 
 Plantar fascia, cut 
 
 Abductor ballucia 
 
 Internal plantar artery 
 
 Flexor brevis digitorum 
 
 Branch of internal plantar to 
 iliiiilnl tirfcries (superficial 
 digital] 
 
 Flexor brevis hallucis 
 
 Princeps hallucis, or fifth plantar 
 digital artery 
 
 Collateral digital branch of princeps 
 
 hallucis to second toe 
 Collateral diiiiinl branch // 
 
 AofitCdfefO iinn-r si<l? of ijrrat toe 
 Collateral digital branch nf/irincrps 
 hallucis to outer side of great toe 
 
 I ic. 273. THE PLANTAR AKTI KIK>. 
 (From a dissection in the Museum of St. Bartholomew's Hospital.) 
 
 
 must find : (i) The theca ajid the thecal culs-de-sac, the synovial sheath of the 
 tendons ; (2) the vincula, delicate thread-like bands of deep fascia ; (3) the ten- 
 dons of the flexor longns digitorum ; (4) the tendons of the flexor brevis digi- 
 torum ; (5) the slits, in tendons of the flexor brevis digitorum ; (6) the grooves 
 on the plantar surfaces of the pedal phalanges ; (7) the outer division of tin- 
 plantar fascia, quite thin, covering the abductor minimi digiti muscle ; (8) the inner 
 division of the plantar fascia, quite thin, covering the abductor hallucis ; (9) the 
 middle division of the plantar fascia, very thick, strong, and glistening, covering 
 the flexor brevis digitorum ; (10) two intermuscular grooves almost under tin- 
 
 
POSTERIOR PART OF LOU'ER EXTREMITY. ?8g 
 
 \J s 
 
 diverging; branches of the V-incision you made in the skin. You will notice that 
 the three divisions of the plantar fascia correspond to the three muscles in the 
 first layer, cover them, and in great part are almost inseparably connected there- 
 with. (Fig. 273.) The plantar fascia is part of the origin of these muscles. 
 Remove this fascia (Figs. 281 and 273) and trace out with the forceps the 
 branches of the internal and external plantar nerves and vessels. (Fig. 272.) 
 
 The plantar fascia has a central part that covers the flexor brevis digitorum ;. 
 an outer portion that covers the abductor minimi cligiti, and is continuous with 
 the dorsal fascia of the foot externally ; an inner portion that covers the abductor 
 
 Part of abductor minimi cligiti 
 
 Flexor brevis minimi digit! 
 
 Trans versus pedis 
 
 Divided tendons of flexor brevis 
 digitorum 
 
 Long plantar (long inferior 
 calcaneo-cuboid) ligament 
 
 Flexor longus hallucis 
 Flexor longus digitorum 
 Tibialis posticus 
 
 Flexor brevis hallucis 
 Adductor hallucis 
 
 Tendon of the flexor longus 
 hallucis 
 
 Tendon of flexor longus digitorum 
 
 FIG. 274. THIRD LAYER OF THE MUSCLES OF THE 
 
 hallucis, and is continuous internally with the dorsal fascia of the foot. Poste- 
 riorly, the plantar fascia is attached to the os calcts ; anteriorly, it is continuous 
 with the ligamenta vaginales. 
 
 Muscles of the First Layer (Fig. 273). Dissect carefully in the grooves 
 between the middle muscle and the muscles on each side of it. Trace all three 
 muscles back to their origins on the os calcis. (Fig. 268.) Likewise trace each 
 forward to its insertion : the abductor liallucis to the base of the first phalanx 
 of the great toe (Fig. 268) ; the abductor minimi digiti to the base of the first 
 phalanx of the little toe ; the flexor brci'is digitorum to the second phalanges 
 of the four lesser toes, by cutting through the ligamenta vaginales the long 
 
390 PRACTICAL ANATOMY. 
 
 way of the tendon. (Fig. 268.) Now cut all three of these muscles and turn 
 them forward, and expose the second layer of muscles. (Fig. 270.) Having 
 cut through the ligamenta vaginales of the toes (Fig. 272), observe that the 
 four tendons of the flexor longus digitorum pass through slits in the four 
 corresponding tendons of the flexor brevis digitorum, in the same manner the 
 deep flexors of the fingers pass through the superficial ones. 
 
 Second Layer (Fig. 270). In the figure of the flexor longus digitorum 
 notice three accessories: (i) The muscular acccssorius (Fig. 268) ; (2) the four 
 limibricales (Fig. 273); (3) a slip of contribution from the tendon of tlie flexor 
 longus Iiallueis. (Fig. 270.) Having studied the origin and insertion of these 
 muscles, divide the flexor longus hallucis and flexor longus digitorum near the 
 os calcis and turn them all forward, as you did the previous layer. 
 
 Third Layer (Fig. 274). Trace out to its origin each one of the three mus- 
 cles inserted into the base of the great toe. Cut down between the two sesamoid 
 bones in the tendon of the flexor brevis hallucis. Trace the tendon of the 
 peroneus longus across the sole of the foot to its insertion into the internal cunei- 
 form and base of great toe metatarsal. (Fig. 275.) 
 
 In the fourth layer we have the dorsal interossei and the plantar interossei. 
 In number they are seven, four being dorsal and three plantar. In action they 
 are analogous to the interossei of the hand. In the foot they are all supplied 
 by the external plantar nerve ; in the hand by the ulnar nerve. 
 
 Function of the Interossei and Lumbricales. It is comprehensive to consider 
 the action of these muscles in this manner in the hand : 
 
 1. All the interossei and lumbricales acting together, flex at the metacarpo- 
 phalangeal articulation and extend at the first and second phalangeal articula- 
 tions. This gives about the position for'holding the pen. 
 
 2. The four dorsal interossei acting alone, abduct the digits. Notice that 
 supination of the forearm is involuntarily associated with abduction of the 
 digits. 
 
 3. The palmar interossei acting alone, adduct the digits. Notice that prona- 
 tion of the forearm is associated involuntarily with adduction of the fingers. In 
 the above I have described the action of these muscles in the hand ; the action 
 in the foot is the same, only less under control of the will, since the foot of man 
 is not a prehensile member. 
 
 4. The adductor line of fingers and toes. The adductor finger is the 
 middle ; the adductor toe is the second. In adduction and abduction the other 
 digits approach and recede from this adductor digit. 
 
 The Adductor Digit. (i) The adductor digit of the hand has no palmar 
 interossei inserted into it ; (2) the adductor digit of hand has two dorsal inter- 
 ossei inserted into it ; the same is true of the foot. 
 
 Difference in Origin. Notice that the dorsal interossei are very large, and 
 arise from the contiguous sides of the metatarsals or metacarpals ; that the 
 palmar are small, and arise from one side only of the metatarsal or metacarpal 
 corresponding to the phalanx into which they are inserted. Practise the 
 movements of the lumbricales and interossei on your own fingers until you 
 master this subject thoroughly. 
 
 Granular Fat. Found in the superficial fascia of the hand and foot palmar 
 and plantar surfaces and in the general supi-rficial fascia of the f(utus and infant. 
 Tin- toughness of this kind of fatty tissue depends on a largi r amount of con- 
 nective tissue. 
 
 Divisions of Plantar Fascia. (i) An outer thin one that covers the ab- 
 ductor minimi digiti. (2) An inner one that covers the abductor Jiallneis. (3) A 
 middle one that covers the flexor bre:<is digitorum. This middle one is very 
 strong. 
 
POSTERIOR PART OF LOWER EXTREMITY. 391 
 
 Ligamenta Vaginales. These are the fibrous sheaths of deep fascia that 
 cover the flexor tendons. They are formed by the deep fascia, in a modified 
 form. Above, they are continuous with the plantar fascia. They are attached 
 on the sides to the margins of the grooves on the plantar surface of the 
 phalanges. 
 
 The Theca and Thecal Culs-de-sac. The vaginal synovial membrane, con- 
 sisting of a visceral and a parietal layer, is called theca. The point in conjunction 
 between the two layers about the middle of the metatarsal bones forms a cul- 
 
 Peroneua longus 
 
 Plantar interossei 
 
 Dorsal interossei 
 
 FIG. 275. FOURTH LAYER OF THE MUSCLES OK THE SOLE. 
 
 de-sac. -Pus forming below in the cavity of the tlicca could burrow to this point. 
 Note the difference in the fingers. 
 
 Normally, the thecal cul-de-sac is found as above described in each toe, thus 
 making five in number. The homologous structures of the fingers are described 
 as three, the thumb and little finger having none, since the thecal synovial mem- 
 brane corresponding to these two members is continuous above with the two 
 bursae under the annular ligament. My experience is, however, that in the 
 majority of cases no communication will be found between the thecal sacs of the 
 thumb and little finger, and the bursse under the anterior annular ligament at 
 the wrist. 
 
 The Vincula. These are small silvery cords that extend from the bottom of 
 
392 PRACTICAL ANATOMY. 
 
 the groove to the tendons, and from tendon to tendon, in the ligamenta vaginales 
 of the digits of the lower as well as the upper extremity. By means ot these 
 vincula capillary vessels reach the synovial membrane of the tendon. 
 
 The Internal Plantar Nerve. Begins under the internal annular ligament 
 at the bifurcation of the posterior tibial nerve. It lies between the first and second 
 layers of muscles in the sole of the foot. (Fig. 272.) It gives off: (i) Articular 
 branches to the tarsus and metatarsus and phalangeal articulations ; (2) a cuta- 
 neous branch to the skin of the heel (Fig. 272) ; (3) digital branches to the 
 inner three and one-half toes ; (4) muscular branches to the abductor hallucis, 
 flexor brevis hallucis, flexor brevis digitorum, and two lumbricals. 
 
 The External Plantar Nerve. Begins at the bifurcation of the posterior 
 tibial ; it accompanies the external plantar artery into the sole of the foot. This 
 nerve is similar in its distribution to the ulnar nerve. It supplies a larger number 
 of muscles, still it is smaller than the internal plantar. The muscles innervated 
 by this nerve are: (i) All the interossei, seven in number, four dorsal and 
 three plantar ; (2) two lumbricals on the outer side ; (3) adductor hallucis ; 
 (4) the transversus pedis. This nerve also supplies one and one-half toes 
 the flexor accessorius and abductor minimi digiti. 
 
 The Internal Plantar Artery (Fig. 273). This is a small artery. It 
 begins with the external plantar ; at the bifurcation of the posterior tibial artery 
 under the internal annular ligament. It accompanies the internal plantar nerve. 
 
 The External Plantar Artery (Fig. 273). This is the larger plantar 
 artery. It crosses the sole of the foot obliquely to the head of the little toe meta- 
 tarsal, lying, of course, in common with all the other plantar structures, between 
 the first and second layers of muscles ; here it turns abruptly inward and forward 
 to the first intermetatarsal space, where it anastomoses with the communicating 
 branch of the dorsalis pedis artery, to complete the plantar arterial arch. 
 
 The Plantar Arterial Arch. This arch is formed between the external 
 plantar artery and the dorsalis pedis. This arch lies deep -on the interossei 
 muscles. It sends off digital branches to the outer three and one-half toes. 
 At the clefts of the toes these digital branches send off perforating branches, 
 which, passing up through the interosseous spaces, communicate with the meta- 
 tarsal artery on the dorsum of the foot. 
 
 Study the origin, insertion, and function ot muscles on your dissection, and 
 use the tabulated list of muscles that each student is expected to prepare for 
 himself for reference. 
 
 Name the muscles of the first layer of the sole of the foot, giving their origin 
 insertion, nerve-supply and blood-supply, and action. 
 
 The Abductor Hallucis. Origin, from the plantar fascia ; greater tuberosity o 
 os calcis ; intermuscular fascia between itself and the flexor brevis digitorum. 
 Insertion, under surface of base of first phalanx of the great toe. This muscle 
 abducts and flexes the great toe. Nerve-supply, the internal plantar nerve. 
 
 The Abductor Minimi Digiti. Origin, plantar fascia ; lesser tuberosity of the 
 os calcis ; the intermuscular septum between itself and the flexor brevis digi- 
 torum ; the long plantar ligament. Insertion, under surface of base of first phalanx 
 of little toe. This muscle abducts the little toe from the mid-line. Nerve-supply, 
 the external plantar. 
 
 The Flexor Brci v\ Digitornin.- Origin, the plantar fascia ; the greater tuber- 
 osity of the os calcis ; the lateral intermuscular fascia. Insertion, into the sides 
 of the middle phalanges. These tendons are perforated by the tendons of the 
 flexor longus digitorum. Nerve-supply, the internal plantar. 
 
 Name the muscles of the second layer of the sole of ike foot, giving origin, inser- 
 tion, function, and ncn'c-snpply. 
 
 Tlic Mnscnliis Accessorius. Origin, tin- concave inner surface of the os calcis 
 
 
 
POSTERIOR PART OF LOWER EXTREMITY. 393 
 
 the under surface of the os calcis ; the long plantar ligament. Insertion, the 
 upper surface and outer oblique border of the flexor longus digitorum. Demon- 
 strate carefully on your dissection the specific double origin and double insertion 
 of this muscle. To do this, hold the heel firmly and extend the toes vigorously. 
 Nerve-supply, the external plantar, a branch of the posterior tibial. 
 
 The lumbrical muscles are four in number. They arise in connection with the 
 tendons of the flexor longus digitorum, as follows : The first from the great-toe 
 side of the first tendon, beginning at the point where this tendon leaves the main 
 tendon of the muscle. The other three arise from the adjacent tendon, as seen in 
 figure 270. Insertion, into the inner border of the expanded tendons of the ex- 
 tensor communis digitorum. The nerve-supply is from the external plantar for 
 the two outer ; the internal plantar for the two inner. Acting with the interossei, 
 these muscles flex the metatarso-phalangeal articulation and extend the first and 
 second interphalangeal joints. Note, then, the homology, both in nerve-supply 
 and function, of these muscles and the lumbricales manus. 
 
 The intimate association of the accessorius and lumbricales pedis with the 
 flexor longus pollicis and flexor longus digitorum justifies some authors in classi- 
 fying these latter also in the second group. For details of these muscles, which 
 are not here considered as belonging to the second, the reader is referred to 
 page 389. 
 
 Name tJic muscles of the third layer of tJu\ sole of tJic foot, giving origin, inser- 
 tion, function, and nerve-supply. 
 
 The Flexor Brevis Hallucis. Origin, from the under surface of the cuboid 
 bone ; the long plantar ligaments ; the expansion of the tibialis posticus in the 
 middle of the sole of the foot. Insertion, base of the first phalanx of the great 
 toe, both on the inner and outer borders. (Fig. 268.) The tendon of the flexor 
 longus hallucis passes between the two parts of the muscle, playing over a pulley 
 formed by the two sesamoid bones developed in the tendon of flexor brevis hal- 
 lucis. (Fig. 274.) This muscle flexes and slightly adducts the first phalanx. 
 
 The Adductor Hallucis (Fig. 274). Origin, the sheath of the peroneus longus 
 formed by the long plantar ligament ; the under surface of the second, third, and 
 fourth metatarsals. Insertion, into the outer part of the base of the first phalanx 
 of the great toe. Nerve-supply, the external plantar. 
 
 The Transversus Pedis (Fig. 274). Origin, the deep transverse metatarsal 
 ligaments and the plantar ligaments of the three outer metatarso-phalangeal 
 articulations. Insertion, into the base of the first phalanx of great toe on the 
 outer side. Nerve-supply, the external plantar. Action, to adduct the great toe. 
 
 The Flexor Brevis Minimi Digiti. Origin, base of fifth metatarsal bone, under 
 surface (Fig. 268); sheath of peroneus longus. (Fig. 274.) Insertion, into the 
 under surface of base of first phalanx of the little toe. Action, to flex the little 
 toe. Nerve-supply, the external plantar. 
 
 The interossei have been fully considered. The student is urged to study 
 carefully the action of these muscles, both separately and in conjunction with the 
 lumbricales. 
 
 26 
 
THE BACK. 
 
 Dissection. Dissection of the back is often almost wholly ignored ; and why 
 ignored? I would ask. Simply because (i) it is considered as belonging to a 
 region of the body called not practical ; because (2) its structures are somewhat 
 difficult to expose on dissection. Says one : "There are only two incisions in the 
 whole category of diseases of this region (i) for renal operations ; (2) for car- 
 buncles. Why, then, should one learn to dissect seven layers of muscles?" I 
 would answer, " If the former incision is made in the proper place, and the latter 
 deep enough, these alone are enough to justify careful study and dissection of this 
 area." I desire to accentuate the following : 
 
 1. The thick superficial fascia, and its very dense connective -tissue frame- 
 work, since this is a favorite locality for boils and carbuncles, offering greater 
 resistance to pus than do all the other structures combined, bet\\een this and the 
 suboccipital triangle. (Law of projectiles.) 
 
 2. The erector spinae and the quadratus lumborum, since these muscles 
 are guides to lumbar colotomy and lumbar nephrectomy and nephrotomy. 
 
 3. The last rib, since in the above operations, nephrectomy and nephrotomy, 
 the pleura must not be cut or wounded, and the last rib is the guide. 
 
 4. The complexus muscle, since this forms the roof of the suboccipital tri- 
 angle. On the floor of the triangle are the vertebral artery and suboccipital 
 nerve ; crossing the triangle, immediately under the complexus muscle, is the 
 great occipital nerve. 
 
 5. The vertebral aponeurosis, since this separates the muscles which act 
 upon the shoulder girdle the first and second layers from the proper muscles 
 of the back viz., those that move the vertebral column by acting on the spinous 
 and transverse processes and the parts of the skull serially continuous therewith. 
 
 6. The erector Spinae, since this is the location of lumbago, the so-called 
 muscular rlicumatism of the back. I wish you to note particularly in this con- 
 nection the anatomical reasons why the pain of lumbago need not be mistaken 
 for pain in diseases of the kidneys and surrounding viscera, of the rectum, and of 
 the uterus. The pain in lumbago (in any of the proper muscles of the back) is 
 logically located in the small of the back, because these muscles are supplied by 
 somatic nerves. It could not be mistaken for the- above pains, because those 
 organs uterus, kidney, rectum have a sympathetic nerve-supply, and this pain 
 is reflected in the distribution of the anterior primary divisions of the somatic 
 nerves; the proper muscles of the back are supplied by the posterior primary 
 divisions of tin- spinal nerves, and these latter have- no sympathetic connections. 
 (See l-'imdamental Principle's of Anatomy: Application of Law of Projectiles 
 in Cases of Pain Remote from Place of Injury.) 
 
 394 
 
THE BACK. 
 
 395 
 
 MUSCLES OF THE BACK, GROUPED ACCORDING TO LAYERS, AND THEIR NERVE-SUPPLY. 
 
 First layer, . . 
 Second layer, . 
 
 Third layer, . 
 Fourth layer, . 
 
 K 
 
 c 
 
 t/i 
 Fifth layer, . >_ 
 
 o 
 G 
 
 W 
 
 Sixth layer, . . 
 Seventh laver, 
 
 Trapezius. Nerve-supply, spinal accessory, cervical plexus. 
 
 Levator anguli scapulae. Nerve-supply, cervical plexus. 
 
 Rhomboideus minor. Nerve-supply, brachial plexus. 
 
 Rhomboideus major. Nerve-supply, brachial plexus. 
 
 Latissimus dorsi. Nerve-supply, the long subscapular. 
 
 Serratus posticus superior. 1 Nerve-supply, posterior divisions of spinals, 
 
 Serratus posticus inferior, j external branches. 
 
 Splenius capitis. ) Nerve-supply, posterior divisions of spinals, external 
 
 Splenius colli. } branches. 
 
 Outer division (nerve-supply, all by posterior divisions, spinal nerves) : 
 
 1. Ileo-costalis. 
 
 2. Musculus accessorius ad ileo-costalem. 
 
 3. Musculus cervicalis ascendens. 
 
 Middle division (nerve-supply, posterior divisions of spinals) : 
 
 1. Musculus longissimus dorsi. 
 
 2. Musculus transversalis colli. 
 
 3. Musculus trachelo-mastoideus. 
 
 Inner division (nerve-supply, posterior divisions of spinals) : 
 
 Musculus spinalis dorsi. 
 Musculus complexus. Nerve-supply, suboccipital, great occipital, posterior 
 
 division. 
 
 Semispinalis colli. Nerve-supply, posterior divisions of spinal. 
 Semispinalis dorsi. Nerve-supply, posterior divisions of spinal. 
 Rotatores spinae. Nerve-supply, posterior divisions of spinal. 
 Multifidus spinae. Nerve-supply, posterior divisions of spinal. 
 
 Interspinales. Nerve-supply, posterior divisions of spinal. 
 Intertransversales. Nerve-supply, posterior divisions of spinal. 
 
 Occipital Group (nerve-supply, suboccipital nerve). Rectus capitis posticus 
 minor, rectus capitis posticus major, rectus capitis lateralis, obliquus superior, 
 obliquus inferior. Nerve-supply, great occipital and suboccipital nerves. 
 
 ANALYSIS OF THE SIMPLE MOVEMENTS OE THE SPINAL 
 COLUMN AND THE MUSCLES WHICH PRODUCE THEM. 
 
 View the skeleton from behind, and note the juxtaposition of spines, laminae, 
 transverse processes, articular processes, and bodies or centra of vertebrae. Note 
 the head of the rib articulating with the body, and the tubercle of the rib articulat- 
 ing with the transverse process of a vertebra. (Fig. 276.) Each is a movable 
 articulation, because it has a synovial sac. Note the central pulpy nature of the 
 intervertebral disc. Note the manner in which the head of the rib articulates 
 with two bodies and the cartilaginous disc, and recall the exceptions to this rule 
 in the first, ninth, tenth, eleventh, and twelfth thoracic vertebrae. (Fig. 277.) 
 
 SIMPLE MOVEMENTS OF THE SPINE. 
 
 1. Lateral flexion of the column by the intertransversales. 
 
 2. Extension of the column by the interspinalcs and spinalis dorsi. 
 
 3. Lateral rotation by the rotatores spinae, extending from the transverse pro- 
 cess of the vertebra below to the lamina of the bone above. 
 
 4. Extension and lateral rotation of the column by the multifidus spinae, in a 
 typical region extending from the transverse processes of the vertebrae below, to 
 the lower border of the spines above, from the last lumbar to the second 
 cervical vertebrae. 
 
 Note that extension and lateral rotation are the two most common move- 
 
39 6 
 
 PRACTICAL ANA TOM}. 
 
 merits of the human vertebral column ; that there are three regions where this 
 movement is specially pronounced: (i) the tlioracic region; (2) the ccrrical 
 region ; (3) the region between the head and neck. 
 
 Anterior costo-central 
 or stellate ligament 
 
 Costo-central synovial 
 sac 
 
 Laminar portion of inter- 
 vertebral disc 
 
 Central pulpy portion of inter- 
 vertebral disc 
 
 Middle costo-trana- 
 verse ligament 
 
 Costo-transverse synovial sac 
 
 Posterior costo-transverse 
 ligament 
 
 FIG. 276. HORIZONTAL SECTION THROUGH THE INTERVKRTEURAL Disc AND RIBS. 
 
 The interartioular 
 ligament 
 
 The superior or anterior 
 costo-transverse ligament! 
 
 The stellate ligament 
 
 FIG. 277. SIIOWIM; THE ANTERIOR COMMON LICAMI.M <>i mi MMNE, AND mi ( > >.\ SECTION 
 
 OF THE RlBS WITH 1111 \KRTEBR>E. 
 
 The semispinalis dorsi, semispinalis colli, and complexus are accessory 
 to the multifulus spin;r. 
 
 Note the means to an end, then, in (i) the semispinalis dorsi (Fig. 285) ex- 
 tending from transverse processes to the spines in such a manner as to strengthen 
 the dorso-rervical junction. The scinispinalis colli is likewise disposed to 
 
THE BACK. 
 
 397 
 
 strengthen the same region. So we will see that from the transverse processes 
 of all the dorsal vertebrae to the spines of all the dorsals and cervicals there 
 is a continuous, uninterrupted plane of oblique muscular fibres. (Fig. 285.) 
 They are called semispinales dorsi and colli. They are synergistic physiologi- 
 cally to the multifidus spinae only a larger edition of the same. Their function 
 is extension and lateral rotation. 
 
 Note, again, there is an upward continuation of this same muscular arrange- 
 ment to the head the complexus, a semispinalis capitis. (Fig. 283.) It arises 
 from the transverse processes of the upper six thoracic and last cervical, and is 
 
 Trapezius 
 
 INION OR EXTERNAL-OCCIPITAL PROTUBERANCE 
 
 SUPERIOR NUCHAL LINE 
 
 Occipito-frovitalia 
 
 MIDDLE NUCHAL LINE 
 Sterno-mastoid 
 
 SpleniuB capitis 
 
 Eectus cap. post. min. 
 Rectus cap. post. maj. 
 
 Superior oblique 
 
 INFERIOR NUCHAL LINE 
 
 Eectus capitis lateralis 
 
 POSTERIOR CONDYLOID 
 FORAMEN 
 
 JUGULAR PROCESS 
 
 BASI-OCCIPITAL 
 
 FIG. 278. THE OCCIPITAL. (External view.) 
 
 inserted into the occipital bone. Its action is extension and lateral rotation of 
 the head. 
 
 The above are the simple movements of the vertebral column. Complex 
 movements may be had by combination of different simple movements. I have 
 spoken of the mechanism in advance of the dissection, to inspire the student to 
 greater care in his work. 
 
 NERVES THAT SUPPLY THE BACK. 
 
 1. Tlie long subscapnlar nerve to the latissimus dorsi (brachial plexus). 
 
 2. The spinal accessory nerve to the trapezius (twelfth cranial nerve). 
 
 3. T/ie snboccipital nerve to the complexus, recti, and oblique muscles. 
 
 4. Muscular branches from the cervical plexus to the rhomboids and levator 
 anguli scapulae. 
 
 5. Posterior divisions of the spinal nerves, thirty-one pairs to other muscles. 
 
 6. The great occipital nerve, to the complexus muscle and to the scalp. 
 Scheme for the Posterior Divisions of the Spinals. All except the first 
 
 cervical divide into internal and external branches ; the internal branches sup- 
 ply the sixth and seventh layers, the external branches the remainder ; they 
 
39 8 PRACTICAL ANATOMY. 
 
 all supply the skin of the back ; there are twelve dorsal cutaneous nerves ; the 
 suboccipital is the first cervical posterior division ; the great occipital is the 
 posterior division of the second cervical ; the third occipital is a branch of the 
 third cervical, posterior division. 
 
 You will find the (i) suboccipital nerve in the suboccipital triangle ; (2) the 
 great occipital under the complexus muscle crossing the suboccipital triangle ; 
 
 (3) the spinal accessory nerve between the trapezius and sterno-mastoid muscles ; 
 
 (4) the third occipital internal to the great occipital ; (5) the suboccipital emerges 
 between the occipital bone and atlas behind the vertebral artery ; (6) the great 
 occipital nerve emerges between the atlas and axis and passes under cover of the 
 complexus muscle through the lower and inner part of the suboccipital triangle ; 
 (7) the great occipital nerve joins the occipital artery under the trapezius and 
 lies on the complexus muscle ; (8) other posterior divisions emerge between the 
 transverse processes. 
 
 Arteries of the back are: (i) the dorsal branches of all the intercostals ; 
 (2) the deep cervical, a branch of the superior intercostal ; (3) the arteria prin- 
 ceps cervicis, a branch of the occipital ; (4) these arteries, represented by num- 
 bers 2 and 3, anastomose under the complexus. 
 
 The student who studies in advance of his dissection the foregoing pages 
 will have no difficulty in making a thorough dissection of the back. 
 
 Dissection. Locate : (i) The spinous processes of the vertebra in the dorsal 
 and lumbar regions ; (2) the iliac crest ; (3) the crest of the scapular spine ; (4) 
 the three lips of the crest of the scapular spine ; (5) the acromion process of the 
 scapula ; (6) the external occipital protuberance ; (7) the vertebra proinincns ; 
 (8) the angles of the ribs, and note the distance they are from the spinous 
 processes; (9) the iliac junction with the sacrum ; (10) the rudimentary sacral 
 spines ; (i i) the ma stoid processes ; (12) the clavicle ; (13) the twelfth rib. 
 
 Incisions. (i) From external occipital protuberance to the rudimentary 
 sacral spines ; (2) from one acromion process of the scapula to the other. Begin 
 to remove the skin at the intersectional point of the vertical and horizontal inci- 
 sions just made. 
 
 Observe the cutaneous nerves piercing the trapezius and latissimus dorsi, on 
 removing the skin. These are the cutaneous branches of the posterior divisions 
 of the spinal nerves. (Fig. 279.) 
 
 Note the very heavy variety of the superficial fascia. This, you will 
 observe, is tightly bound to the deep fascia by fibrous trabeculaj that make 
 removal of the skin difficult. This fascia, especially in the region of the neck, 
 is a common place for boils and carbuncles. Observe the great depth you will 
 have to cut to get through this fascia. 
 
 Clean all the superficial fascia off and make your work look like figure 22~ . 
 Here you have exposed two muscles : (i) The trapo/ius ; (2) the latissimus dorsi. 
 
 The Trapezius. Trace its origin to the external occipital protuberance, the 
 inner third of the superior nuchal line, the ligamentum nuclijc, the seventh cer- 
 vical spine, and all the dorsal spines. Now pull the arm outward (Fig. 280), and 
 put the muscle on the stretch. Study its descending fibres to the outer third of 
 the clavicle and acromion ; its ascending and horizontal ones to the upper lip of 
 tin- spine of the scapula. 
 
 Develop the lower margin of the trape/.ius muscle, and observe that it overlaps 
 the latissimus dorsi. Find the space between the trapezius and sterno-cleido-mas- 
 toid muscle. Locate in this space the spinal accessory nerve, and trace the 
 
THE BACK. 
 
 399 
 
 same to the trapezius. Also trace the nerve upward to where it comes through 
 the sterno-cleido-mastoid muscle. 
 
 Latissimus Dorsi. Trace the origin to the six lower thoracic spines, lum- 
 
 Semi-apinalis 
 
 Multifldus spinae 
 
 LongissimuB 
 dorai 
 
 Ilio-oostalia 
 
 Rhomboideua 
 major 
 
 Latiaaimua 
 dorsi 
 
 Gluteus 
 maximus 
 
 FIG. 279. DISTRIBUTION OF THE POSTERIOR PRIMARY DIVISIONS OK THE SHXAI. 
 
 NERVES. (Henle.) 
 
 bar aponeurosis, and iliac crest, posterior one-third ot outer lip. Develop the 
 upper border and expose the infraspinatus and teres major in the triangle formed by 
 this muscle, the deltoid, and the trapezius. (Fig. 280.) Develop with the scissors 
 the lower border of the muscle. The latissimus dorsi will be inserted into the poste- 
 
400 PRACTICAL ANATOMY. 
 
 nor lip ofthe bicipital groove of the humerus with the major tereal muscle. These 
 two muscles, the trapezius and the latissimus dorsi, may now be removed by cut- 
 ting through their origins, tracing the same carefully to their respective inser- 
 tions, where they may be detached, when you will have exposed (Fig. 281) : 
 
 1. The musculus levator anguli scapulae. 
 
 2. The musculus rhomboideus minor. 
 
 3. The musculus rhomboideus major. 
 
 4. The musculus splenius capitis. 
 
 5. The musculus complexus. 
 
 6. The musculus serratus posticus inferior and superior. 
 
 7. Vertebral aponeurosis. 
 
 8. The occipital artery on the complexus muscle. 
 
 9. The great occipital nerve. 
 
 Now develop with scissors the four serrations of insertion into the lower four 
 ribs of the serratus posticus inferior. This muscle arises from the spines of the 
 eleventh and twelfth thoracic, and the first and second dorsal vertebrae. Pull 
 the arm outward, and put the rhomboids on the stretch. Study their insertion 
 into the middle lip of the vertebral border of the scapula. Develop their 
 spinous origin. (Fig. -281.) 
 
 Cut the rhomboids near their origins and turn them outward. (Fig. 281.) 
 See the nerve-supply on the under surface near the centre. See also the pos- 
 terior scapular artery, a continuation of the transversalis colli artery. 
 
 The rhomboideus minor (Fig. 281) arises from the spine of the seventh 
 cervical and first thoracic vertebrae, and from the ligamentum nuchae. It is 
 inserted into the vertebral border of the scapula opposite the spine. Its nerve- 
 supply is from the brachial plexus. 
 
 The rhomboideus major (Fig. 281) arises from the five upper thoracic ver- 
 tebrae and their supraspinous ligament, and is inserted into the middle lip of the 
 vertebral border of the scapula from a point opposite the spine above to the in- 
 ferior angle below. The nerve-supply is from the brachial plexus. The action 
 of the rhomboids is to lift the scapula upward, backward, and inward. 
 
 Levator Anguli Scapulae (Fig. 281). Pull the arm outward and find the in- 
 sertion of this muscle into the middle lip of the vertebral border of the scapula 
 above the spine. Trace its three or four tendons of origin to the anterior tubercles 
 of the transverse processes of the four upper cervical vertebrae. This muscle deri\ is 
 its nerve-supply from the cervical plexus. Its action is to elevate the scapula 
 and. by producing rotation of the same, it depresses the point of the scapula. 
 
 Serratus Posticus Superior (descending fibres) (Fig. 282). This muscle 
 lies under the levator anguli scapulae and rhomboids. It arises by aponeurosis 
 from the seventh cervical spine and the upper three dorsal spines. It is inserted 
 into the second, third, fourth, and fifth ribs, a little beyond the angle. The 
 nerve-supply is from the posterior primary divisions of the second and third 
 intercostals. 
 
 The serratus posticus inferior (ascending fibres) (Fig. 282) arises, by 
 aponeurosis, from the two lower dorsal and three upper lumbar spines; it is 
 inserted into the four lower ribs a little beyond the angle. Notice the difference 
 between the two serrati museles. The upper is inserted into the upper border, 
 the lower into the lower border of ribs. 
 
 The Vertebral Aponeurosis (Fig. 2X2). Internally you see this aponeurosis 
 alt. idled to the spines ; externally it is attached to the angles of the ribs ; below 
 it blends with the serratus postieus inferior and latissimus dorsi ; above it passes 
 behind the superior serratus. It separate's the proper muscles of the back from 
 those that act on the shoulder girdle. 
 
 The Splenius Capitis and Colli. Develop the long, pointed origin of this 
 
THE BACK. 
 
 401 
 
 Triceps 
 
 Teres minor 
 Ini'raspinatus 
 
 Teres major 
 
 Bhotnboideus major 
 
 Pectoralis major 
 
 Obliquus externus 
 
 Gluteus mediu 
 
 Gluteus maximus 
 
 FIG. 280. FIRST LAYER OF MUSCLES OF THE HACK. 
 
402 
 
 PRACTICAL ANATOMY. 
 
 muscle from the sides of the spines of the seventh cervical and six upper dorsal 
 vertebne. (Fig. 281.) The muscle has two insertions: (i) into the mastoid 
 
 Supraapinatus 
 
 Obliquua interims 
 
 Complexua 
 Splenius oapitii 
 
 Levator anguli scapulae 
 
 Serratua posticus 
 superior 
 
 Rhomboideus minor 
 
 Spleniua colli 
 Rhomboideua major 
 
 281. 'I'm l.i \ \iou AM. ri. i SCAPULA AM> RHOMBOIDEI. 
 
 process of the temporal bone ; (2) into the posterior tubercles of the transverse- 
 processes of the three upper cervical vertebrae. The nerve-supply is from the 
 posterior primary divisions of the cervical nerves. 
 
THE BACK. 
 
 43 
 
 Erector Spinae and Branches. Remove the vertebral aponeurosis (Fig. 
 282) and expose the fifth layer of muscles and its subdivisions. (Fig. 283.) 
 
 Complexus 
 
 Splenius capitia 
 
 Splenius colli 
 
 Serratus postieus superior 
 
 Vertebral aponeurosis 
 
 Serratus postieus 
 inferior 
 
 Obliquus interims 
 
 Origin of latissimus 
 dorsi 
 
 SEVENTH CERVICAL VERTEBRA 
 
 TWELFTH THORACIC VERTEBRA 
 
 FIFTH LUMBAR VERTEBRA 
 
 FIG. 282. THE THIRD AND FOURTH LAYERS OF THE MUSCLES OF THE HACK. 
 
 Origin. (i) The spines of the two last thoracic, all the lumbar, and the four 
 upper sacral vertebrae ; (2) the back of the side portion of the fourth sacral 
 
404 
 
 PR A CTICAL ANA TOMY. 
 
 vertebra; (3) the posterior sacro-iliac ligament, a few of these fibres being 
 continuous with the origin of the gluteus maximus ; (4) the upper part of the 
 
 ComplexuB 
 Trachelo-mastoid 
 
 Traneversalis colli 
 
 Longissimuo dorsi 
 
 Accessor-jus ad ilio- 
 ooatalein 
 
 Spinalis dorsi 
 
 Ilio-costalis 
 
 Obliquus internus 
 
 Erector epinae 
 
 SEVENTH CERVICAL VERTEBRA 
 
 TWELFTH THORACIO VERTEBRA 
 
 FIFTH LUMBAR VERTEBRA 
 
 IMC;. 283. Tin. KII-TII I.AYKK OF TDK Mfsci.Es UK run HACK. 
 
 posterior superior spine of the ilium, and the posterior fifth of the iliac ere. 1 
 
 (Morris). 
 
THE BACK. 405 
 
 Insertion. It is continuous abov r e with the spinalis dorsi, longissimus dorsi, 
 and ilio-costalis. 
 
 Locate the spinalis dorsi first, the inner insertion of the erector spinae 
 muscle. Remember it takes its origin from the inner part of the erector spinae. 
 Trace its tendons of insertion to the spines of the upper thoracic vertebrae. 
 
 Locate the groove between the outer and middle divisions of the erector 
 spinae. In this groove you will find the external branches of the posterior 
 divisions of the spinal nerves, in company with the dorsal branches of the inter- 
 costal vessels. Turn the muscles apart, as in figure 284. 
 
 The outer division of the erector spinae is called ilio-COStalis, to its insertion 
 into the angles of the lower ribs, from the sixth to the eleventh rib. It is continued 
 upward through the back and neck as (i) the accessorius, (2) cervicalis ascendens. 
 
 Accessorius ad ilio-costalem arises from the angles of the ribs, seventh to 
 eleventh, and is inserted into the angles of the ribs from the second to the fifth, 
 and into the transverse process of the seventh cervical vertebra. 
 
 Cervicalis ascendens arises from the ribs fourth to fifth upper internal to 
 the costal insertion of the accessorius, and is inserted into the posterior tubercles 
 of the fourth, fifth, and sixth cervical transverse processes. 
 
 The middle division of the erector spinae continues through the thorax under 
 the name of longissimus dorsi ; through the neck, to the head, as the trans- 
 versalis colli and trachelo-mastoid. (Fig. 284.) 
 
 The longissimus dorsi arises: (i) From the middle part of the erector 
 spinae ; (2) from the transverse processes of some of the lower thoracic vertebras. 
 It is inserted into : (i) The ribs external to their tubercles ; (2) the transverse 
 processes of the thoracic vertebras ; (3) into the accessory tubercles of the upper 
 lumbar and lower thoracic vertebrae ; (4) into the transverse processes of the 
 upper lumbar vertebrae. 
 
 Transversalis colli arises from the transverse processes of the upper six 
 thoracic vertebrae, internal to the insertion of the longissimus dorsi. It is in- 
 serted into the posterior tubercles of the transverse processes of the vertebrae from 
 the second to the sixth cervical vertebrae inclusive. 
 
 The trachelo-mastoid (Fig. 284) is the inner part of the transversalis colli 
 continued in the mastoid process. In some cases this muscle is unusually well 
 developed. 
 
 The sixth layer of muscles comprises the following : 
 
 1. The complexus, or semispinalis capitis. 
 
 2. The semispinalis dorsi in the dorsal region. 
 
 3. The semispinalis colli in the cervical region. 
 
 4. The multifidus spinae, found in all regions of the spine. 
 
 5. The rotatores spinae, found in the thoracic region. 
 Describe the complexus muscle. 
 
 This muscle (Figs. 283 and 284) is covered by the splenius, with its two 
 divisions, and the trapezius. In turn, this complexus covers the muscles that 
 make the boundaries of the suboccipital triangle, thereby forming the roof of this 
 important surgical area the suboccipital triangle. The occipital artery lies on 
 the muscle ; the suboccipital and great occipital nerves are under the muscle, 
 being parts of the contents of the suboccipital triangle. The origin of the muscle 
 is from : (i) The articular processes of the cervical vertebra? from the third to the 
 sixth ; the transverse processes of the seventh cervical and the six upper thoracic 
 vertebras. The insertion is into the occipital bone, between the middle and 
 inferior curved or nuchal lines. (Fig. 278.) Nerve-supply: (i) The suboccipital 
 or posterior primary division of the first cervical ; (2) the great occipital or 
 posterior primary division of the second cervical ; (3) the posterior primary 
 divisions of the third, fourth, and fifth cervical nerves. 
 
406 
 
 PRACTICAL ANATOMY. 
 
 Obliquua superior 
 
 Rectus capitis posticus major - 
 Obliquus inferior 
 Trachelo-mastoid 
 
 Transversalis oolli 
 Cervicalis ascendena 
 
 Accessorius ad ilio- 
 costalem 
 
 Ilio-costalis 
 
 Insertion of ilio-costalia 
 upon lumbar transverse 
 processes 
 
 Rectus capitis posticus minor 
 
 SEVENTH CERVICAL VERTEBRA 
 
 LongisBirnus dorai 
 
 TWELFTH THORACIC VERTEBRA 
 
 FIFTH LUMBAR VERTEBRA 
 Erector spinae 
 
 IMG. 284. TIIK FII-TII LAYKK OF IMF MUSCLKS Of mi- BACK, AI-TER SITAKATINC; HIK 
 
 i H I I l: AM) MlMUI.K DlV|sM>NS. 
 
THE BACK. 407 
 
 Describe tlic semispinalis dorsi. 
 
 The idea in the name is founded on the facts : (i) That one of the muscle is 
 inserted into the spines, and (2) that the muscle is situated in the thoracic or dorsal 
 region of the spine. (Fig. 285.) The muscles composing the series are small and 
 tendinous. They extend obliquely inward and upward, from their origin, on the 
 back of the transverse processes of the thoracic vertebrae, from the sixth to the 
 tenth, to their insertion into the spines of the last two cervical and the first, 
 second, third, and fourth thoracic. The nerve-supply is from the posterior 
 primary divisions of the thoracic nerves. Remove this muscle and you expose 
 the multifidus spinae below. The muscle is covered by the spinalis dorsi 
 and latissimus dorsi the inner and middle parts of the erector spins, you will 
 remember. 
 
 Describe tJie semispinalis colli. 
 
 The verbal idea is the same in this as in the preceding muscle. The muscle 
 is located in the cervical region ; it is inserted into the spines of the cervical 
 vertebrae, from the second to the fifth inclusive. (Fig. 285.) The muscle originates 
 from the transverse processes of the five or six upper thoracic vertebrae. The 
 muscle is covered by the complexus ; under it is the multifidus spinae. Between 
 the complexus and semispinalis colli you will find : (i) Branches of the posterior 
 cervical nerves ; (2) an anastomosis between the arteria princeps cervicis, a branch 
 of the occipital, and the arteria profunda cervicis, a branch of the superior inter- 
 costal. In ligatfon of the common carotid and subclavian arteries blood may 
 reach both the hand and brain by this channel. 
 
 Describe the nmltifidus spines. 
 
 The multifidus spinae is found in every region of the spine. In the sacral and 
 lumbar regions it is thick and fleshy ; in the thoracic and cervical regions it is 
 thin and aponeurotic. This muscle has the following origins, which must be 
 carefully learned before this muscle can be dissected understandingly : 
 
 (i) From the deep surface of the erector spinae. This fact of origin makes the 
 dissection of the muscle a difficult task, except in cases of zinc or formaline pre- 
 pared bodies where the cadavers have had a year to become very hard ; (2) 
 from the groove between the sacral spines and rudimentary articular processes 
 of the sacrum ; (3) from the mammillary processes of the lumbar vertebrae ; (4) 
 the transverse processes of all the thoracic vertebrae ; (5) the articular processes 
 of the cervical vertebrae from the fourth to the sixth, and from the transverse 
 process of the seventh cervical. The segments making up the collective multi- 
 fidus spinae from these diverse regions are inserted as follows : into the lower 
 borders of the vertebral spines, from the fifth lumbar to the second cervical. 
 The nerve-supply of the multifidus spinae is from the posterior primary divisions 
 of the spinal nerves, from the second cervical to the third sacral nerve. This 
 muscle covers the rotatores spinae. 
 
 Describe the rotatores spiiue. 
 
 These are in the region of the thorax. They derive their name from the 
 rotatory action they exert. Of these muscles there are eleven pairs. They 
 originate from the back and upper part of the transverse processes, and are 
 inserted into the lower border of the lamina of the next vertebra above. They 
 are in relation above with the multifidus spinae. Nerve-supply, the posterior 
 primary divisions of the spinals. 
 
 Name and describe the seventh layer of muscles of the back. 
 
 (i) The interspinales arise from the upper surface of the spine of a lower, and 
 are inserted into the lower surface of the spine of the vertebra immediately 
 above. These muscles are very small. Nerve-supply, the posterior primary 
 divisions of the spinals. (2) The intertransversales arise from the transverse 
 process below and are inserted into the one above. They are small muscles. 
 
408 
 
 PRACTICAL ANATOMY. 
 
 They are principally in the cervical and lumbar regions. Nerve-supply, from the 
 spinals as they emerge from the intervertebral foramina. 
 
 Compleius 
 
 Obliquua superior 
 
 Reotua capitia poaticua major 
 
 Obliquua inferior 
 
 Multifldua spinae 
 
 Semispinalia oolli 
 Cervioalia aacendens 
 
 LonKiaaimus dorsi 
 
 Levator eoatse 
 
 Longiesimus dorai 
 Ilio-ooataliB 
 
 Obliquus internua 
 Lumbar fascia 
 
 Ilio-coatalia 
 
 Kectua capitis poaticub 
 minor 
 
 SEVENTH CERVICAL VERTEBRA 
 
 Semispmalis dorai 
 
 Multifldua apinae 
 
 TWELFTH THORACIC VERTEBRA 
 
 Multifldua apinae 
 
 FIFTH LUMBAR VERTEBRA 
 
 Itifldus spiuce 
 
 l-ii.. 285. TIIK SIMM I.AM'.K en- TIII-: Mi M i.i-s 01 im-. I;\CK. 
 
 I. The Complcxns. Remove the longissimus dorsi and its continuation 
 through the neck and to the head the transvcrsalis colli and the trachdo- 
 
THE BACK. 409 
 
 mastoid. The complexus will be seen arising from : (i) The back of the artic- 
 ular processes of the cervical vertebrae from the third to the sixth ; (2) the back 
 of the transverse processes of the seventh cervical and the six upper thoracic 
 vertebrae ; (3) generally also by an inner head from the spine of the seventh cer- 
 vical vertebra. It is inserted into the occipital bone, between the superior and 
 inferior nuchal lines. (Fig. 283.) 
 
 Carefully detach the insertion of this muscle and you will expose : (i) The 
 suboccipital triangle, containing the vertebral artery and the suboccipital nerve ; 
 (2) on the under part of the muscle you will find the suboccipital nerve and the 
 great occipital nerve ; (3) the recti and oblique muscles ; (4) the semispinalis colli, 
 coming to a large abrupt insertion into the spine of the axis. 
 
 The suboccipital triangle has (Fig. 285) : 
 
 A roof formed by the complexus muscle. 
 
 A floor formed by the arch of the atlas and atlo-occipital ligament. 
 
 An inner border formed by rectus capitis posticus major. 
 
 A lower border formed by inferior oblique muscle. 
 
 An upper border formed by superior oblique muscle. 
 
 The contents are the vertebral artery and suboccipital nerve. 
 
 It is traversed by the great occipital nerve. 
 
 The suboccipital muscles (Fig. 285) : 
 
 1. The obliquns capitis inferior, which extends from the spine of the axis to 
 the transverse process of the atlas. 
 
 2. The obliquns capitis superior, which extends from the transverse process of 
 the atlas to the inferior nuchal line of the occipital bone. 
 
 3. The rectus capitis posticus major, which extends from the spine of the 
 axis to inferior nuchal line, middle one-third. 
 
 4. The rectus capitis posticus minor extends from the tubercle of the atlas to 
 the inner one-third of the inferior nuchal line. 
 
 5. The rectus capitis later alls extends from the lateral mass of the atlas to the 
 jugular process of the occipital bone. 
 
 Now remove from its origin (i) the complexus, and as you turn the body of 
 the muscle from the semispinalis colli, you will see between these two muscles 
 some vessels the anastomosis between the arteria profunda cervicalis, a branch 
 of the first or superior intercostal, and the arteria princeps cervicis, a branch of 
 the occipital. (Fig. 40.) You will find a large mass of veins here, too. In 
 cases of ligation of the subclavian or common carotid artery, this is the principal 
 channel by which the blood passes to form a collateral circulation. (2) Remove 
 any remaining part of the spinalis dorsi or longissimus dorsi and make your 
 work look like figure 285. 
 
 You have remaining the other members of the sixth and seventh groups : 
 (i) The semispinalis dorsi ; (2) the semispinalis colli; (3) the multifidus spinae. 
 These were explained under the head of " Analysis of the Simple Movements of 
 the Spinal Column," to which you are referred on page 395. Remove the three 
 muscles just given, and dissect (4) the rotatores, (5) the intertransversales, (6) the 
 interspinales, according to their previous description, just referred to. 
 
 i . Give the cutaneous nerve-supply of the back. 
 
 The scalp is supplied by (i) the great occipital ; (2) the suboccipital ; (3) the 
 third occipital. These are all spinal nerves. The remainder is supplied by the 
 posterior divisions of the spinal nerves. Next the spine you will see some small 
 nerves coming through to the skin. (Fig. 279.) These are cutaneous twigs 
 from the internal branches of the posterior divisions of the spinal nerves. A 
 little distance from the spine you will see nerves coming through the trapezius 
 and latissimus dorsi. These are the external cutaneous branches of the posterior 
 divisions of the spinal nerves. 
 27 
 
410 PRACTICAL ANATOMY. 
 
 2. Explain internal and external brandies of t/ie posterior divisions of tJie spinal 
 nerves. 
 
 The internal branches are small, and supply the sixth and seventh groups of 
 muscles and the skin on each side of the spine for an inch or two inches. The 
 external branches supply all the other proper muscles of the back and the 
 remainder of the skin. All the thirty-one pairs of posterior divisions of spinal 
 nerves divide as previously indicated, except the first. This is called the suboccipital 
 nerve. 
 
 3. Define ivhat is meant by proper muscles of the back. 
 
 All those muscles not acting on the shoulder girdle ; those under the verte- 
 bral aponeurosis. 
 
 4. Give a description of the superficial fascia of the back. 
 
 It is very thick and dense, and contains granular fat. Abscesses often form 
 here. A favorite place for carbuncles is in the superficial fascia of the neck. 
 
 5. Name the muscles of the back not supplied principally by the posterior divi- 
 sions of the spinal nerves. 
 
 The trapezius, the latissimus dorsi, the levator anguli scapulae, and the rhom- 
 boids, major and minor. 
 
 SHORT SUMMARY OF THE CRANIAL NERVES. 
 
 Hoiv arc the cranial nerves classified ? 
 
 According to the new classification of cranial nerves there are twelve pairs, 
 enumerated serially from before backward, from the olfactory, or first, to the 
 hypoglossal, or twelfth, inclusive. This classification was proposed by Soemmer- 
 ing in 1778. Prior to this time the classification of Willis had been in use for 
 more than a century, by which classification only ten pairs were recognized. 
 
 Make a further distinction between the classifications of the cranial nerves by 
 Socmmcring and Willis. 
 
 In the seventh pair Willis included both the/ada/, a nerve of motion, and 
 the auditory, a nerve of the special sense of hearing. The eighth pair of Willis 
 included the ninth, tenth, and eleventh nerves of our classification. The ninth 
 pair of Willis included the hypoglossal, and the tenth pair of Willis included the 
 first cervical, called the suboccipital nerve. 
 
 What is understood by superficial and deep origins of cranial nerves f 
 
 By the former is meant the place where the nerve is seen attached to the 
 surface of the brain (Fig. 92) ; by the latter is- meant the place deeply located, 
 called a nucleus of gray matter, to which the motor part of nerves can be traced. 
 
 Docs not tlie sensorv part of nerves also have a deep origin f 
 
 Properly speaking, the sensory parts of nerves have their origin in the cells 
 of the posterior root ganglia of the nerve-trunks, to which ganglia special atten- 
 tion must be given in the dissection of both cranial and spinal nerves. The 
 sensory fibres originating in the ganglia grow inward to this nuclei, and, as far 
 as is known, form there no direct connection with the nerve-cells. 
 
 Is there any correspondence between the origins of the cranial nerves and the 
 origins of the spinal nerves f 
 
 Yes ; each has a superficial and a deep origin. The superficial origin of the spinal 
 nerves is readily seen on removing the spinal cord from its neural canal. The 
 deep origin of the spinal nerves is from tin- anterior and posterior horns of the 
 gray crescents of the interior horns of the spinal cord. 
 
 \VItat further resemblance between crania/ and spinal nerves may be mentioned / 
 
 (l) Fibres from the deep origin of eaeh pass upward and are connected with 
 the cortex of the cerebrum ; (2) the pneumo^astric nerve arises by motor and 
 sensory roots from nuclei which are derivatives of the anterior and posterior 
 
THE BACK. 411 
 
 horns respectively of the spinal cord ; (3) the ganglion on the sensory root of 
 the fifth cranial nerve and the ganglion on the root of the vagus are homologous 
 to the ganglia on the posterior roots of the spinal nerves ; (4) cases are recorded 
 of absence of the ganglion on the posterior root of the first spinal or suboccipital 
 nerve ; (5) cases are recorded of the hypoglossal the twelfth cranial nerve 
 having a posterior root with a ganglion. Possibly anomalous cases like those 
 cited in 4 and 5 may account for and even justify the tenth cranial nerve the 
 hypoglossal in the classification by Willis. 
 
 In iv hat respects do spinal nerves differ from cranial nerves / 
 
 In the following respects : (i) Spinals arise from the spinal cord ; (2) spinals 
 have an anterior motor and a posterior sensory root ; (3) spinals have a ganglion 
 on each posterior root ; (4) spinals have no special sense nerves. 
 
 State where the ganglia of the posterior or sensory roots of the spinal nerves may 
 be found in dissecting. 
 
 The rule is that these ganglia occupy the posterior root of the spinal nerve, 
 just behind the union of the anterior and posterior roots, in the intervertebral 
 foramen. 
 
 Are there any exceptions to the rule governing the location of the spinal 
 ganglion / 
 
 Yes ; the ganglia of the first and second cervical nerves lie on the neural 
 arches of the atlas and axis. The ganglia of the sacral and coccygeal nerves 
 are in the spinal canal. 
 
 Describe the vagus or pneumogastric nerve. 
 
 This nerve is the tenth cranial, according to the classification of Soemmering ; 
 it is also called the nervus vagus and the nervus par vagam. The nerve leaves 
 the base of the cranium by the central part of the jugular foramen with the spinal 
 accessory and glosso-pharyngeal nerves. 
 
 Where is the ganglion of the root of the vagus located, and to what does it corre- 
 spond morphologically ? 
 
 It is located in the jugular foramen, and corresponds to the spinal ganglion on 
 the posterior roots of the spinal nerves. 
 
 What is the importance of the ganglion of the root of the vagus nerve ? 
 
 It has connections with the sympathetic, spinal accessory, glosso-pharyngeal, 
 and facial nerves. (Fig. 293.) 
 
 Where is the ganglion of the trunk of the vagus nerve and ivliat its impor- 
 tance ? 
 
 It is a little below the ganglion of the root and below the base of the skull. 
 Its importance is due to the fact that branches are given off from it to the sympa- 
 thetic, to the cervical nerves, and to the hypoglossal nerve ; also the accessory 
 part of the spinal accessory nerve joins the vagus at this point. (Fig. 293.) 
 
 Describe the olfactory nerve. 
 
 The olfactory nerve, as generally understood, is in reality a dismembered part 
 of the fore-brain of the foetus. It consists of four parts, as may be appreciated by 
 consulting figure 286. 
 
 1. The olfactory roots, three in number. 
 
 2. The olfactory tract, a slender bundle. 
 
 3. The olfactory bulb, resting on the cribrosa. 
 
 4. The olfactory filaments, about twenty in number. 
 Name and give the source of the olfactory roots. 
 
 The middle root is attached to the under surface of the frontal lobe ; the 
 internal root to the gyrus fornicatus ; the external root to the temporo-sphenoidal 
 lobe. The roots meet to form the olfactory tract. The tract becomes bulbous 
 and occupies a fissure on the under surface of the frontal lobe of the cerebrum, 
 called the olfactory sulcus. The olfactory nerves are given off from the under 
 
412 
 
 PRACTICAL ANATOMY. 
 
 part of the bulb. The nerves are about twenty in number on each side. They 
 pass through the olfactory foramina in the cribriform plate of the ethmoid bone. 
 In their course through the foramina, the nerves are invested by a sheath of 
 dura mater. (Fig. 87.) The olfactory nerve filaments are distributed to the 
 mucous membrane of the upper and middle turbinated bones, and to a corre- 
 sponding part of the septum nasi. (Fig. 75.) 
 
 Describe tJie optic nerve. 
 
 This nerve is the special nerve of sight, being distributed solely to the eye- 
 ball. The commissure is the place on the sphenoid bone where the two sides 
 
 ffulA 
 
 Ot feretory filaments 
 
 FIG. 286. FIRST CRANIAL NERVE, OLFACTORY. 
 
 are connected. The optic nerve proper is between the commissure and the eye- 
 ball ; the optic tract is between the commissure and the brain. 
 
 Describe the optic tract. 
 
 It arises (Fig. 92) : (i) From the pulvinar of the optic thalamus ; (2) from 
 the geniculate body ; (3) from the upper quadrigeminal body. The tract crosses 
 the crus cerebri (Fig. 92), being closely attached thereto, and terminates in the 
 optic chiasma or commissure. The student will recall the fact that the optic 
 chiasma and the optic tracts assist the crura cerebri and pons Varolii in forming 
 the boundaries of the interpeduncular space. (Fig. 92.) 
 
 Longitudinal Fibers- 
 Decussating Fibers 
 Intcrcerehral Fibers 
 Inter-retinal Fibers 
 
 FIG. 287. SECOND CRANIAL NIRVK, Orru. 
 
 Describe the optic ncri'c proper. 
 
 This nerve extends from the chiasma to the eyeball. It leaves the cranium 
 by the optic foramen, in the sphenoid bone, in company with the ophthalmic 
 artery. The nerve has a cranial part and an orbital part ; the latter is flexuous, 
 to accommodate the movements of the eyeball, and is surrounded by ciliary 
 vessels and nerves. 
 
 /// practical anatomy i^Iicrc do you find tJic artcria ccntralis retuuc / 
 
 This must In- seen in a dissection of the contents of the orbit. (Fig. 103.) 
 You will find this artery piercing the under part ojf the nerve, and about midway 
 between the optic forair.en and the globe. 
 
THE BACK. 413 
 
 The she at J i of the optic nerve is derived from what source / 
 
 It is derived from the dura mater coming through the optic foramen and de- 
 laminating ; one layer ensheathes the optic nerve, the other forms the orbital 
 periosteum. (Fig. 95.) 
 
 The third cranial nerve the motor oculi supplies : (i) The ciliary muscle of 
 the eyeball ; (2) the sphincter muscle of the iris ; (3) all the muscles of the eye- 
 ball except the superior oblique and the external rectus. 
 
 This nerve arises beneath the floor of the aqueduct of Sylvius. On removing 
 the brain from the cranium, you see the nerve between the crura cerebri. (Fig. 
 92.) The nerve pierces the dura midway between the anterior and posterior 
 
 FIG. 288. THIRD CRANIAL NERVE, MOTOR OCULI. 
 
 clinoid processes, and enters the cavernous sinus ; in the sinus it lies above and 
 internal to the fourth nerve. (Figs. 8688.) The nerve divides behind the 
 sphenoidal fissure into a superior and an inferior division. (Fig. 86.) These two 
 divisions enter the orbit by the sphenoidal fissure, passing between the two heads 
 of the external rectus muscle. (Fig. 101.) The superior division supplies the 
 superior rectus muscle and the levator palpebrae ; the inferior division has the 
 remaining part of the distribution of the third nerve. 
 
 \VJiat can yon say of the fourth cranial, or patJieticns? 
 
 It is also called the trochlear nerve, from the fact that it supplies the superior 
 oblique muscle of the eyeball only. This nerve has a long course in the cranial 
 cavity. In dissection you see the nerve just under the margin of the anterior 
 
 FIG. 289. FOURTH CRANIAL NERVE, TROCHLEAR. 
 
 free border of the tentorium cerebelli, and soon piercing the dura to the outer 
 side of the posterior clinoid process, to gain the cavernous sinus. (Fig. 98.) 
 This nerve is the smallest of the cranial nerves ; it enters the orbit by the sphe- 
 noidal fissure. The nerve has its 'deep origin in the floor of the aqueduct of 
 Sylvius. 
 
 Describe briefly the fifth cranial or trifacial nerve. 
 
 This nerve is specialized almost exclusively for the prehension and mastication 
 of food directly or indirectly. It will be noted that the relation between this and 
 other nerves depends upon the near or remote association these latter bear to the 
 functions of the fifth nerve. Take notice, then, of the function of the trigeminus, 
 
414 
 
 PRACTICAL ANATOMY. 
 
 as follows : (i) The fifth nerve supplies with sensation all the teeth. (2) The fifth 
 nerve supplies with sensation the gums, by little nerves called the nervi gingivales. 
 (3) The fifth nerve supplies the sides of the tongue, and the anterior one-half of 
 the same through its lingual or gustatory branch. (4) The fifth nerve supplies 
 the muscles of mastication with motion muscles whose function is to move the 
 mandible. (5) The fifth nerve supplies the temporo-mandibular articulation, be- 
 cause the muscles it supplies move this articulation. The same branch that sup- 
 plies the articulation, the auriculo-temporal, also supplies the drum of the ear 
 and the auditory canal, because these parts are secondary in the acquisition of 
 food. (6) The fifth nerve supplies the skin covering the fullest region of the 
 
 FIG. 290. FIFTH CRANIAL NI.KVK. 
 
 muscles of mastication ; in round numbers, the cutaneous region in front of a line 
 passing from side to side through the auditory meatuses is supplied by the auri- 
 culo-temporal, supraorbital, infraorbital, and mental branches of this nerve. (7) 
 The fifth nerve supplies the anterior belly of the digastric muscle and the mylo- 
 hyoid muscle, but these muscles are depressors of the mandible. (8) The fifth 
 nerve has numerous connections with the facial nerve. Study the facial anil 
 temporal relations between these- two nerves ; tin- chorda tympani ; the otic, sub- 
 maxillary, and Meckel's ganglia. The trifacial nerve supplies the muscles of 
 mastication with motion, and the skin covering these muscles. 
 
 ll'/itif can you .sv/r of tlic si.vtli cranial )icrvc / 
 
 This nerve is distributed solely to the external rectus muscle. It arises from 
 
THE BACK. 
 
 415 
 
 the floor of the fourth ventricle. It may be seen in dissection piercing the dura 
 below and internal to the fifth nerve. (Fig. 88.) In the cavernous sinus the 
 nerve lies on the outer side of and is attached to the internal carotid artery. 
 (Fig. 88.) In the sinus the sixth nerve is joined by sympathetic filaments from 
 the cavernous plexus, and receives a twig from the ophthalmic branch of the 
 fifth nerve. (Fig. 98.) 
 
 The Seventh or Facial Nerve. (i) Leaves the cranium by the internal audi- 
 tory meatus in company with the auditory or eighth cranial nerve and the audi- 
 tory artery, a branch of the basilar artery. (2) In the internal auditory canal it 
 is connected to the auditory nerve by the pars intermedia, and enters a separate 
 bony canal, called the aqueductus Fallopii, one-quarter of an inch from the in- 
 ternal auditory meatus. (3) On nearing the tympanum the nerve turns sharply 
 backward and presents an enlargement, called the intumescentia gangliformis (gen- 
 
 Supnavrbifal 3?! 1 
 
 FIG. 291. SEVENTH CRANIAL NERVE, FACIAL, OR PORTIA DURA. 
 
 Great petrosal, to form Vidian with No. 5. 2. Small petrosal, to otic ganglion. 3. External petrosal, 
 to plexus on mid-meningeal artery. 4. Tympanic branch to stapedius, etc. 5. Branch from carotid 
 plexus making Vidian, with No. I. 6, 7. Branches to auriculo-temporal of fifth. 8. Branch to 
 auricular of vagus. M. The ganglion of Meckel. O. A. F. Orifice of aqueductus fallopii. 
 
 iculate ganglion). (4) From the geniculate ganglion are the following branches : 
 (a] The large superficial petrosal to Meckel's ganglion. This branch leaves the 
 cranium by the foramen lacerum medium, and joins a branch from the carotid 
 sympathetic plexus, called the large deep petrosal, to form the Vidian nerve. (/?) 
 The small superficial petrosal to the otic ganglion. This nerve leaves the 
 cranium by the canalis innominatus, a small opening between the foramen ovale 
 and the foramen spinosum, in the greater wing of the sphenoid bone. This branch 
 receives a communicating twig from the tympanic branch of the glosso-pharyn- 
 geal nerve, (r) The external superficial petrosal nerve, to join the sympathetic 
 on the middle meningeal artery. (5) The facial nerve traverses the middle ear 
 in its bony canal, traversing between the roof and inner wall, and between the 
 inner wall and the posterior, successively, emerging at the stylo-mastoid foramen. 
 (6) In the middle ear the nerve gives off (a] a small branch to the stapedius 
 muscle ; (b] the chorda tympani, which supplies the submaxillary and sublingual 
 
416 
 
 PRACTICAL ANATOMY. 
 
 glands with secretory and vaso-dilator fibres, and the anterior part of the tongue 
 with taste fibres. The facial supplies the stylo-hyoid, the posterior bell}- of the 
 digastric, all the dermal muscles about the ear, the posterior belly of the occipito- 
 frontalis, and all the muscles of facial expression. (7) The facial nerve commu- 
 nicates with the three divisions of the fifth on the face ; with the spheno-palatine. 
 otic, and submaxillary ganglia ; with the auditor}', vagus, sympathetic, and glosso- 
 pharyngeal nerves. 
 
 Dcsoibc briefly the auditory nerve. 
 
 This is the eighth cranial nerve. It leaves the cranium by the internal auditory 
 meatus with the auditory artery a branch of the basilar and the seventh or facial 
 
 OPHTHALMIC SUPERIOR MA.\I I.L.I I! Y 1. \7-7-.7.' ini; MAXILLA I! Y 
 \ 
 
 GASSEJ;I.\\ 
 
 x.i/.iA.A. 
 
 FICIAL I'ETHOSAI. 
 
 //r 7.1 A, 
 
 r. i. v.i A /.s . 
 
 TUBARIVS 
 
 FENESTRA OVA US AM> 
 ROTUNDA I\ Till': /.V.V /;/.' 
 MM I.L 
 
 FACIAL NERVE 
 
 EXTERNAL 
 SUPERFICIAL 
 PETROSAL 
 
 ANTERIOR WALL 
 
 POSTERIOR WALL 
 
 FIG. 292. Box ILLUSTRATION OF SEVENTH CRANIAL NERVK IN RELATION TO THE MIDDLE 
 
 EAR OR TYMPANUM. 
 
 For puqx>ses of aiding ihe memory, the tympanum is compared to a box. The reader is referred to 
 page 135 for a full description of the figure. 
 
 nerve. In the auditory canal it communicates with the seventh nerve by the pars 
 intermedia. The eighth is the nerve of the special sense of hearing. (For the 
 distribution of this nerve see Morris.) 
 
 Describe the glosso-pliaryngeal nerre. 
 
 This is the ninth cranial nerve. It escapes from the cranium by the jugular 
 foranu-n with the tenth and eleventh nerves and the jugular vein. The nerve 
 has two ganglia: (i) The jugular and (2) the petrosal ganglion. The ninth 
 nerve distributes branches to the mucous membrane of the tongue, pharynx, 
 tympanum, and also to the stylo-phary ngeus muscle. It supplies the otic gano- 
 lion ria its communications with the small superficial petrosal branch of the 
 
THE BACK. 417 
 
 seventh nerve. This nerve communicates with the third division of the fifth 
 nerve ; with the facial, sympathetic, and vagus. 
 
 What can you say of the function of the vagus ? 
 
 In animals less highly specialized than man the term pneumogastric 
 expresses practically all that can be said of this nerve, since in its wandering 
 distribution it supplies the organs of voice and respiration with motion and sensa- 
 tion ; the organs of circulation and digestion with motion only. The vagus, 
 then, has to do with the two greatest sources of metabolism : the ingestion of food 
 and air. Man is not all stomach and lung. By synecdoche, however, stomach 
 may represent a complicated digestive apparatus, and lung an equally differ- 
 entiated apparatus, in which the blood throws off CO 2 and loads up with O, 
 according to the law of the diffusion of gases. Now, the student must remember 
 this : The names of the branches of the vagus nerve will be governed and deter- 
 mined by the following conditions : 
 
 1. The arbitrary subdivision of the alimentary canal, to which the vagus is 
 distributed. 
 
 2. The arbitrary subdivisions of the respiratory system, to which the vagus is 
 distributed. 
 
 3. The sympathetic nerve-branches to both the respiratory and digestive 
 systems, since the sympathetic is the nerve of organic life. 
 
 4. The organs, or systems of organs, associated secondarily with the respira- 
 tory and digestive processes. The tongue, for example, is associated with both 
 respiratory and digestive processes, and while this organ has its own specific nerve- 
 supply, upon which its sensation and motion depend, still, the orderly adjustment 
 of internal to external relations could not occur, were there no communication 
 between the nerve-supply of the tongue, which forces food into the pharynx, and 
 the organs that deliver this food to the stomach. In like manner there must be 
 unanimity of action between the lungs, vocal cords, and tongue, for vocalizing and 
 linguistic purposes ; this unanimity must depend on an uninterrupted communi- 
 cation between the nerve-supply of the tongue and the vagus nerve. Observe 
 the difference in facial expression of the two men, the one of whom is in the 
 nausea period of a malarial attack, the other of whom is enjoying an after-dinner 
 cigar. The facial nerve supplies the muscles of expression, and by its communi- 
 cation with the vagus both comfort and distress in the stomach are facially 
 expressed. 
 
 PHYSIOLOGICAL REASONS FOR THE NUMEROUS COMMUNICATIONS OF THE VAGUS 
 
 NERVE. 
 
 1 . With the spinal accessory nerve. The spinal part of the spinal accessory 
 nerve is distributed to the sterno-cleido-mastoid andtrapezius muscles, and assists 
 in forming the cervical plexus. It will be remembered that the mission of the 
 cervical plexus is to supply the diaphragm and certain muscles of forced respira- 
 tion, as well as the depressor muscles of the hyoid bone. (Page 73.) 'Now, the 
 accessory part of the spinal accessory nerve supplies the muscles of the soft 
 palate. Thus, by the communication between the vagus and the spinal acces- 
 sory, harmony is established between the muscles that rhythmically enlarge and 
 reduce the size of the thorax, and the lungs that occupy this thorax, and by 
 their rhythmic movements carry on vocal and respiratory processes. 
 
 2. I Vith the petrous ganglion of the glosso-pharyngcal or ninth cranial nerve. 
 This nerve has a distribution as follows : (i) To the tongue ; (2) to the pharynx 
 via the pharyngeal plexus ; (3) to the middle ear, Eustachian tube, and mastoid 
 cells via the tympanic plexus ; (4) to the parotid gland via its small superficial 
 petrosal branch and the otic ganglion ; (5) to the facial nerve ; (6) to the sympa- 
 
418 
 
 PRACTICAL ANATOMY. 
 
 thetic nerve. In the communications, then, between the pneumogastric and the 
 glosso-pharyngeal nerve, we see the connecting link between a mechanism 
 pumping air, under the direction of the vagus, and a territory to be constantly 
 
 he B 1 ^ Pair of Nerves 
 
 comprising the 
 9*. h or G I os so- pharyngeal 
 10V or Pneumogastnc, 
 . 1 1 l . h or Spinal Accessory. 
 
 Terminal Brs 
 
 , fivm Tetteri Com/undofAnntomij. 
 
 IK;. 293. EIGHTH J'AIR UK CRANIAL NERVES. 
 
 i. Jugular ganglion of ninth nerve. 2. Petrous ganglion of ninth nerVe. 3. Ganglion of the vagus root. 
 
 4. Ganglion of the vagus trunk. 5. Medullary part of eleventh nerve. 6. Spinal part of eleventh 
 
 nerve. 7. Superior cardiac branch joining cardiac of sympathetic. 8. Subclavian artery, mi right 
 
 tide, arch of the aorta, on lefi side <>f the l><>dy. <>. Koramen magnum, receiving spinal par) of the 
 
 spinal arct^-ory. IO. Jugular l.-iainrn , transmitting all tlircc nerves; also (ailed the foramen laeeium 
 
 pdsterius. ii. Branches to hypoglossal, sympathetic, cervical nerves. 12. Olivary body (in broken 
 
 line). 
 
 ventilated the middle ear and Kustachian tube, a territory whose delicate 
 structures might be invparably (lania-cd, \vrre not the sensor)' sentinel, the 
 tympanic plexus, thnv i<> ri'L'.ul.itf the ingress and egress of air. And note, too, 
 
THE BACK. 419 
 
 the expression of anguish on the patient's face when the middle ear is the seat of 
 pain ; an expression determined by the auricular communicating branch of the 
 ninth nerve with the seventh or facial nerve, and also with the pneumogastric 
 nerve, as represented in figure 293. 
 
 3. Wit I i the Jiypoglossal nerve, by which the movements of the tongue are 
 harmonized with both deglutition and vocal action. 
 
 4. WitJi the sympathetic nerve, by which the action of the heart and lungs 
 may be brought into harmony with their environment. 
 
 The physiological communications of the vagus nerve are : 
 
 1. With the spinal accessory nerve. 
 
 2. With the glosso-pharyngeal nerve. 
 
 3. With the hypoglossal nerve. 
 
 4. With the sympathetic nerve. 
 
 5. With the first and second cervicals. 
 
 6. With the facial or seventh cranial nerve. 
 
 This communication is for the purpose of harmonizing respiration and the 
 ingestion of food, in their broadest terms, in consonance with a conservative and 
 aesthetic adjustment of inner to outer relations. 
 
 Name the brancJics of the vagus nerve. 
 
 1. A recurrent branch to the dura mater. 
 
 2. The auricular branch, given off from the ganglion of the root, is joined by 
 a branch of the petrous ganglion of the glosso-pharyngeal. (Fig. 293.) This 
 branch divides into two : one communicates with the posterior auricular branch 
 of the facial, the other joins the facial nerve in its canal. The auricular branch 
 of the tenth cranial nerve is called Arnold's nerve. 
 
 3. The pharyngeal is the prime motor nerve of the pharynx. It unites with 
 the glosso-pharyngeal, superior laryngeal, and sympathetic branches to form the 
 pharyngeal plexus. The principal fibres of the pharyngeal branch of the pneumo- 
 gastric are derived from the accessory part of the spinal accessory nerve. 
 
 4. The superior laryngeal nerve is the nerve of sensation to the mucous mem- 
 brane of the larynx, and of motion to the crico-thyroid muscle. 
 
 5. The inferior laryngeal nerve is the motor nerve to all the intrinsic muscles 
 of the larynx except the crico-thyroid. This is also called the recurrent laryn- 
 geal. 
 
 6. The cervical cardiac branches communicate with the sympathetic, and pass 
 to the superficial and deep cardiac plexuses. 
 
 7. The thoracic cardiac branch has a double origin : (i) From the trunk of 
 the vagus ; (2) from the recurrent laryngeal nerve. They are distributed to the 
 cardiac plexus. 
 
 8. The anterior pulmonary branches unite with the sympathetic to form the 
 anterior pulmonary plexus, which is found on the front of the root of the lung. 
 
 9. The posterior pulmonary branches unite with sympathetic nerves to form 
 the posterior pulmonary plexus. This is larger than the preceding, and found on 
 the posterior part of the root of the lung. (Fig. 151.) 
 
 10. The cesophageal plexus supplies the oesophagus and pericardium. It is 
 formed by the union of branches from both the right and left pneumogastric 
 nerves. The plexus is also called the plexus guise, because gula means gullet. 
 
 1 1. The terminal branches are the gastric. The branches from the left vagus 
 supply the anterior, those from the right the posterior, surface of the stomach. 
 They unite with the sympathetics and assist also in forming the splenic and 
 hepatic plexuses. 
 
 Describe tJie spinal accessory nerve. 
 
 This is the eleventh cranial nerve. It leaves the cranium by the jugular 
 foramen with the ninth and tenth nerves and the internal jugular vein. It has : 
 
420 
 
 PR A CTICAL ANA TO MY. 
 
 (i) A spinal part and (2) an accessory or internal part. The spinal part you 
 will trace to the trapezius and sterno-mastoid muscles. The accessor}' part 
 passes forward to the superior laryngeal nerve and pharyngeal plexus. 
 
 Describe tlic hypoglossal or twelfth nerve. 
 
 This is the motor nerve of the tongue. It leaves the cranium by the anterior 
 condyloid foramen. It supplies the depressor muscles of the hyoid bone in 
 association with the first three cervical nerves. It communicates with the vagus, 
 lingual, sympathetic, and upper three cervical nerves. 
 
ARTICULATIONS. LIGAMENTS. 
 
 1 . WJiat is an articulation ? 
 
 Union of bone to bone, bone to cartilage, or cartilage to cartilage, by means of 
 modified periosteum called ligaments. 
 
 2. What are some of the ends subserved by articulations / 
 
 Stability, as in the joints of the cranium ; motility, as in the extremities ; 
 semistability, as in the pelvis and vertebral column. 
 
 3 . Name and indicate the function of the structures found in a typical articula- 
 tion for motility. 
 
 (i) There is bone for strength and solidity ; (2) a shell or covering of bone, 
 free from vessels and nerves, adapted to bear pressure ; (3) a highly polished 
 articular cartilage to confer elasticity and reduce friction ; (4) a capsular ligament, 
 of periosteal derivation, attached above and below the joint to the bones party to 
 the articulation ; (5) a synovial membrane, with its articular vessels and nerves, 
 closely investing the interior of the capsule, for the secretion of synovia. 
 
 4. Name the structures found in an articulation intended for stability. 
 
 Bones with variously shaped edges, whose union in the very young is legal- 
 ized by periosteum called sutural ligament. 
 
 5. Name structures found in an articulation wlicrc semistability is to be attained. 
 Bony surfaces firmly united by discs of cartilage, which admit of slight 
 
 motion, and under certain physiological conditions as pregnancy develop par- 
 tial synovial membrane. 
 
 6. Are there any technical terms by zvhich tlie artiadations, as above classed, are 
 designated / 
 
 SVNARTHROSIS includes all immovable articulations where bone is joined to 
 bone by variously shaped borders, as toothed, grooved, scaled, sawlike, and seam- 
 like. 
 
 AMPHIARTHROSIS includes all articulations in which bone is firmly united to 
 bone by cartilage, with slight movement, as in the pelvis and vertebral column, 
 and a spasmodic production of synovia, as the case may require ; as in pregnancy, 
 this may be the case. 
 
 DIARTHROSIS includes all articulations with perfect capsules, free movement, 
 and constant production of synovia. 
 
 7. Does the degree of motion vary in articulations ? 
 
 Yes ; and the following subdivisions of the class diarthrosis express the 
 variety or kind of movement, in accordance principally with the degree of motion, 
 as determine'd by the shape of the articular surfaces : (i) Enarthrosis, or ball- 
 and-socket variety, in which there is movement in four modified angular direc- 
 tions. Examples of this are seen in the hip, shoulder, and carpo-metacarpal 
 articulation of the thumb. (2) Condylarthrosis, in which free movement, as in the 
 ball-and-socket articulation, is inhibited. Instance, the temporo-maxillary, occi- 
 pito-atlantal, radio-carpal, metacarpo-phalangeal, and metatarso-phalangeal joints. 
 In each, as you may demonstrate on yourselves, there is free movement as 
 flexion and extension in two directions, but very limited movement from side 
 
 421 
 
422 PRACTICAL ANATOMY. 
 
 to side. Observe the free movement of the fingers on the metacarpals forward 
 and backward, and the limited movement from side to side. The movement of 
 lower jaw is the same. We can see plainly that this variety of joint is a com- 
 promise between ball-and-socket and the hinge -joint. (3) Ginglymus, or hinge- 
 joint t in which there is free movement in two directions, as in the elbow, knee, 
 ankle, and interphalangeals of all the digits of both feet and hands. In these 
 articulations note the impossibility of lateral movement without violence ; note 
 the intermediate position between this variety and the ball-and-socket variety, 
 occupied by the preceding condylarthrosis subdivision. (4) Lateral ginglymns 
 is a term used to express a subdivision of movable joint which differs from the 
 hinge movement in no essential, except in the direction of motion. The supe- 
 rior and inferior radio-ulnar articulations and the atlanto-oclontoid belong to 
 this subdivision. (5) Arthrodia includes the simplest subdivisions of all the 
 movable articulations. In this kind the surfaces are plane, or nearly so. The 
 movements are limited, by virtue of the strong and unyielding nature of the liga- 
 ments, which represent the lowest organized variety of capsular ligament. Kx- 
 amples of this subdivision are in the carpal and tarsal articulations ; between 
 the metacarpals and metatarsals ; in the articular processes of the vertebrae ; in 
 the costo-transverse and interchondral articulations. 
 
 I desire you to dissect and study the movable articulations the diarthroses 
 according to the following outline : 
 
 1 . Give the name of the class diarthrosis, for example. 
 
 2. Give the name of the subdivisions of the class. 
 
 3. Give the technical name of the locality. 
 
 4. Give the osteological units in the joint. 
 
 5. Give subdivisional parts of osteological units. 
 
 6. Name the articular surfaces according to the rule. 
 
 7. Give the basis of a movable joint a capsule. 
 
 8. Give the local subdivisions of the capsule. 
 
 9. Name the strengthening bands of the capsule, if any. 
 
 10. Name the incorporated tendons of obsolete muscles, if any. 
 
 1 1. Name the bony limitations of movements of the joint. 
 
 12. Name the nerve-supply and blood-supply of the joint. 
 
 13. Name the ligamentous muscles of the joint. 
 
 Let us review now the above outline, and understand its specific scope. 
 
 1. There are five subdivisions of the class diarthrosis. (Page 424.) Ky 
 examining the articulation, you find movement in two directions. Your entry 
 should read : Class, diarthrosis ; Subdivision, ginglymus. 
 
 2. Let us assume the particular joint is the elbow : then the technical name- 
 is humero-radio-ulnar articulation ; the common name, elbow-joint. 
 
 3. The osteological units in this joint are the humerus, radius, and ulna. 
 
 4. The subdivisional parts of the osteological units are the outer and inner 
 humeral condyles, radial head of humerus, head of radius, olecranon process 
 of ulna, coronoid process of ulna, greater sigmoid cavity of ulna. 
 
 5. Articular surfaces should take the name of the occupant. Then in this 
 joint we find the radial and ulnar surfaces of the humerus ; the humeral surfaces 
 of the ratlins and ulna. The ulnar surface of the humerus is called technical!}' the 
 trochlear or pulley surface ; the radial surface of the humerus is called the 
 capitcllum, or link- head. 
 
 6. The basic principle in every movable joint is a capsule derived from peri- 
 osteum, linrd by a more or less extrusive synovial membrane. 
 
 7. The subdivisions of the capsule are anterior, posterior, internal lateral, ami 
 external ligaments. A complete capsule is equal to the sum of its subdivisional 
 parts. The usage by which capsules are thus subdivided is a useless (except 
 
ARTICULA TIONS. LIGAMENTS. 4 2 3 
 
 for locating lacerations in rare instances) as well as an arbitrary practice. There 
 is no well-defined line of demarcation between a lateral and an anterior part of 
 a capsule, as the student may expect to find, since transitions in anatomy are 
 easy and gradual. 
 
 8. Strengthening or accessory bands are derived either from the deep fascia 
 or from the aponeurosis of a muscle crossing a joint. 
 
 9. By incorporation of tendons in a capsule, the capsule becomes stronger 
 where the incorporation occurs. Growth is the correlative of function, you will 
 remember ; now, if from change in environment an animal acquire altered body 
 movements, a muscle may migrate from its primitive insertion below a joint to 
 an acquired insertion above a joint. Loss of function entails loss of specific char- 
 acter ; in this case loss of specific character that is, loss of muscular element 
 leaves only the connective-tissue framework crossing the joint. The muscle 
 migrated, the tendon became divorced, and by vigorous retrogression of muscle, 
 a band of connective tissue remains which strengthens the capsule ; the original 
 tendon became incorporated with the capsule. The divorced tendon of the 
 adductor magnus obtains as the internal lateral ligament of the knee-joint ; that 
 of the peroneus longus as the external lateral ligament. The coraco-humeral 
 ligament is the divorced tendon of the minor pectoral muscle. The greater 
 sacro-sciatic ligament is the divorced tendon of the biceps femoris. The liga- 
 mentum teres in the hip-joint is said by Morris to be in all probability the 
 divorced tendon of the pectineus muscle. 
 
 10. The movements of joints are often limited by bone. Note should be 
 taken of these physiological limitations on the cadaver when you dissect liga- 
 ments. 
 
 1 1. Ligamentous muscles to a joint are such muscles as cross a joint. The 
 biceps, brachialis anticus, triceps, and all the muscles getting origin from the 
 
 'humeral condyles are ligamentous in their action to the elbow-joint. Muscles 
 as the rectus femoris and the sartorius may be ligamentous to more than one 
 joint. Ligamentous muscles are also called the elastic ligaments of a joint. 
 
 12. Note the entrance of nerves and vessels that supply the synovial mem- 
 brane. Such structures are designated articular. In this connection refer to 
 Hilton's law governing articular nerves. This law is given in the introductory 
 chapter of this book on page 19. 
 
 13. Finally, having found in the make-up of movable joints bone, articular 
 lamella, cartilage, ligament, tendon, muscle, synovial membrane, nerve, and 
 blood-vessels, be able to classify these structures histologically, according to the 
 outline given in the beginning of this work under caption of anatomical tissues. 
 The plan just outlined for your guidance will not only give you a thorough un- 
 derstanding of the ligaments, but will refresh your memory on those very prac- 
 tical points you will so much need in your subsequent medical studies, both as 
 students and as practitioners of medicine. 
 
 Whenever you are in doubt as to the name of a particular subdivision of a 
 class, consult the following table, taken from Morris : 
 
 TABLE OF THE VARIOUS CLASSES OF JOINTS. 
 
 Class. Examples. 
 
 I. Synarthrosis 
 
 (a) True sutures Lambdoid, sagittal, coronal. 
 
 (^) False sutures Internasal. Intermaxillary. Costo-chondral. 
 
 (c) Grooved sutures Vomer and rostrum of sphenoid. 
 
 II. Amphiarthrosis Bodies of vertebras. Symphysis pubis, sacro- 
 
 iliac, sacro-coccygeal. 
 
424 
 
 PRACTICAL ANATOMY. 
 
 TABLE OF THE VARIOUS CLASSES OF JOINTS. (Continued.') 
 
 Class. 
 III. Diarthrosis 
 
 (a) Enarthrosis . . . 
 (b} Condylarthrosis . 
 
 (c) Ginglymus or Trochlearthrosis . 
 
 (d) Trochoides or Lateral Ginglymus 
 
 (<?) Arthrodia : 
 
 (i) Simple 
 
 (2) Saddle-shaped 
 
 Examples. 
 
 Shoulder. Hip. Astragalo-scaphoid. 
 
 Temporo-mandibular. Occipito-atlantal. 
 Radio-carpal. Metacarpo - phalangeal. 
 Metatarso-phalangeal. 
 
 Elbow. Ankle. Knee. Interphalangeal of 
 fingers and toes. 
 
 Atlanto-odontoid. Superior Radio-ulnar. In- 
 ferior Radio-ulnar. 
 
 Lateral atlanto-axoidean. The joints between 
 the articular processes of the vertebras, costo- 
 transverse, and interchondral. Acromio- 
 clavicular. Carpal. Carpo-metacarpal of 
 four fingers. Intermetacarpal. Tar sal. 
 Tarso-metatarsal. Intermetatarsal. Cal- 
 caneo-astragaloid. Superior and inferior 
 tibio-fibular. 
 
 Sterno-costo-clavicular. Carpo-metacarpal of 
 thumb. Calcaneo-cuboid. 
 
 The following is a list of the principal articulations of the immovable class 
 synarthrosis. Let the student locate these joints on the skull : 
 
 COMPOUND. 
 
 BASE. 
 
 ADJUNCT. 
 
 I. Temporo-parietal. 
 
 Temporal. 
 
 Parietal. 
 
 2. Interparietal. 
 
 Parietal. 
 
 Parietal. 
 
 3. Pronto-parietal. 
 
 Frontal. 
 
 Parietal. 
 
 4. Occipito-parietal. 
 
 Occipital. 
 
 Parietal. 
 
 5. Masto-parietal. 
 
 Mastoid. 
 
 Parietal. 
 
 6. Squamo-parietal. 
 
 Squamosa. 
 
 Parietal. 
 
 7. Occipito-sphenoidal. 
 
 Occipital. Sphenoid. 
 
 8. Occipito-temporal. 
 
 Occipital. Temporal. 
 
 9. Spheno-temporal. 
 
 Sphenoid. 
 
 Temporal. 
 
 10. Spheno-frontal. 
 
 Sphenoid. 
 
 Frontal. 
 
 n. Spheno-ethmoidal. 
 
 Sphenoid. Ethmoid. 
 
 12. Fronto-ethmoidal. 
 
 Frontal. Ethmoid. 
 
 13. Fronto-maxillary. 
 
 Frontal. Maxillary. 
 
 14. Fronto-nasal. 
 
 Frontal. Nasal. 
 
 15. Fronto-lachrymal. 
 
 Frontal. Lachrymal. 
 
 1 6. Fronto-malar. 
 
 Frontal. 
 
 Malar. 
 
 17. Lachrymo-ethmoidal. 
 
 Lachrymal. 
 
 Ethmoid. 
 
 18. Naso-maxillary. 
 
 Nasal. 
 
 Maxillary. 
 
 19. Malo-maxillary. 
 
 Malar. 
 
 Maxillary. 
 
 20. Costo-chondral. 
 
 Costal (Rib). 
 
 Chondrum. 
 
 The following are the members of the group of amphiarthrosis articulations. 
 Their number is small. Remember, the opposed bony surfaces are united by 
 discs of cartilage; there is slight movement, clue principally to the elastic nature 
 of the discs of cartilage. A partial synovial membrane may be developed during 
 pivgnancy : 
 
 1. The intervertebral or intercentral articulations. 
 
 2. The sacro-iliac synchrondrosis. 
 
 3. The sacro-coccygeal articulation. 
 
 4. The intercoccygeal articulations. 
 
 5. The interpubic articulation symphysis pubis. 
 
AR TICULA TIONS. LIGAMENTS. 
 
 425 
 
 TEMPORO-MANDIBULAR ARTICULATION. 
 
 1. Locate and give the synonym for temporo-mandibular articulation. 
 
 This articulation is between the glenoid fossa of the temporal bone and the 
 condyle of the mandible or lower jaw-bone. It is also called temporo-maxillary 
 articulation. 
 
 2. Name some of the conditions that make this articulation one of practical im- 
 portance in medicine and surgery. 
 
 Passing over the part this joint plays in the mastication of food, since this is 
 too well understood by the student to need explanation, we may mention the 
 following : () Temporo-mandibular fixity may occur in cases of exposed tooth- 
 pulp. The nerve supplying the pulp, the trigeminus, also supplies the muscles 
 of mastication. Here, then, we have a moto -sensory reflex circuit. The power- 
 ful contraction of the muscles will cease on the administration of an anaesthetic. 
 
 Interarticular flbro- 
 
 cartilage 
 
 SECTION THROUGH CONOYLE 
 Posterior portion of 
 capsule 
 
 Spheno-mandibul 
 
 Stylo-mandibular ligament 
 
 FIG. 294. VERTICAL SECTION THROUGH THE CONDYLE OF JAW TO SHOW THE Two SYNOVIAL 
 
 SACS AND THE INTERARTICULAR FlBRO-CARTILAGE. 
 
 I once saw a case of fixed jaw produced by a bug in the ear. Here was the 
 same moto-sensory reflex circuit. The same nerve that supplies the muscles of 
 mastication the fifth cranial also supplies the auditory canal through its auriculo- 
 temporal branch. In this case no ordinary traction would open the mouth. An 
 elderly lady suggested the curative property of warm salt-water in "lock-jaw." 
 The ear was filled with water, the bug came out, and instantly the patient could 
 open her mouth, (b) The condyle glides forward onto the eminentia articularis 
 (Fig. 58) when the mouth is open. In this position a dislocation may occur. 
 The condyle is deeply lodged in the glenoid cavity when the mouth is closed. 
 In this position a blow on the chin may fracture the tympanic wall ; while a 
 blow on the angle of the jaw may break the thin dome of the glenoid, and 
 produce injury to the brain. 
 
 3. Hoiv is the glenoid cavity limited in front and beltind / 
 
 Anteriorly, by the eminentia articularis ; posteriorly, by the Glaserian fissure 
 and the post-glenoid tubercle. 
 28 
 
426 PRACTICAL ANATOMY. 
 
 4. H<nv many synovial cavities has the tcmporo-mandibular articulation and 
 /low are they produced ? 
 
 It has two ; they are produced by interposition of the interarticular fibro- 
 cartilage. The periphery of this disc is attached to the capsule. (Fig. 294.) 
 
 5. Explain the use of this interarticular cartilage. 
 
 When the mouth is opened, the condyle of the mandible slides forward onto 
 the eminentia articularis, in the concave cup of the articular cartilage ; when the 
 mouth is shut, the condyle and cartilage recede into the glenoid. (Fig. 59.) 
 
 6. By what are the condyle and cartilage drawn forward f 
 
 By the external pterygoid muscle, a portion of the muscle being inserted into 
 the cartilage as well as into the condyle. (Fig. 58.) 
 
 DISSECTION. 
 
 It is to be hoped that the foregoing has prepared the student to begin an 
 intelligent dissection of the articulations. 
 
 TEMPORO-MANDIBULAR ARTICULATION. 
 
 1 . Class. Diarthrosis, because there is free motion. 
 
 2. Subdivision. Condylarthrosis, because axial rotation is absent. 
 
 3. Osteological Units. Mandible and temporal bone. 
 
 4. Subdivisional Parts. Condylar process and glenoid cavity. 
 
 5. Articular Surfaces. Condylar of temporal ; temporal of condyle. 
 
 6. Basis. A complete capsule lined by synovial membrane. 
 
 7. Subdivisions. Anterior, posterior, internal, and external portions. 
 
 8. Accessories. Spheno-mandibular, stylo-mandibular, fibro-cartilage. 
 
 9. Incorporation of Tendons. None. 
 
 10. Limitations. Articular eminence, post-glenoid tubercle. 
 
 1 1. Ligamcntous Muscles. Internal and external pterygoids,masseter. 
 
 12. Nerve-supply. Masseteric and auriculo-temporal of the fifth. 
 
 13. Blood-supply. Temporal, middle meningeal, ascending pharyngeal. 
 
 1. Name the osteological parts concerned in t/iis articulation. 
 
 (i) The zygomatic arch ; (2) the spine of the sphenoid ; (3) the styloid pro- 
 cess of the temporal bone ; (4) the lingula of the mandible ; (5) the eminentia 
 articularis of the temporal bone ; (6) the post-glenoid tubercle and tympanic plate 
 of the temporal bone ; (7) the Glaserian fissure of the temporal bone. 
 
 2. Give attachments of the spheno-mandibular ligament as you find them, and 
 tell by what nerve this ligament is pierced. 
 
 The ligament extends from the spine of the greater wing of the sphenoid bone 
 to the lingula or mandibular spine, and is perforated by the mylo-hyoid nerve. 
 
 3. Locate and give attachments of tJic stylo-mandibular ligament. 
 
 It is between the masseter and internal pterygoid muscles ; it is attached to 
 the styloid process and to the angle of the mandible. (Fig. 296.) 
 
 SHOULDER-JOINT. 
 
 1. Class. Diarthrosis, because of free motion. 
 
 2. Subdivision. Knarthrodia an^nl.ir movements and axial rotation. 
 
 3. I'eclinienl \,ime. I lutnero-scapular ; common name, shoulder-joint. 
 
 4. Osteological ('nits. Humerus and scapula. 
 
ARTJCULA TIONS. LIGAMENTS. 
 
 427 
 
 5. Subdivisional Parts. Head of humerus, glenoid of scapula. 
 
 6. Articular Surfaces. Humeral of scapula, scapular of humerus. 
 
 7. Basis. A complete capsule lined by synovial membrane. 
 
 8. Subdivisions. Not subdivided for description. 
 
 9. Strengthening Bands. Three gleno-humeral ligaments. 
 
 
 , ^iiiu External portion 
 of capsule 
 
 Stylo-mandibular ligament 
 
 Fit;. 295. EXTERNAL VIEW OF TEMPORO-MANDIBULAR JOINT. 
 
 Internal portion 
 of capsule 
 
 Spheno-mandibular 
 ligament 
 
 Btylo-maudibular 
 ligament 
 
 FIG. 296. INTERNAL VIEW OF TEMPORO-MANDIBULAR JOINT. 
 
 10. Incorporated tendon of pectoralis minor in primitive man. 
 
 11. Limitations. Clavicle, acromion, and coracoid process. 
 
 12. Nerve-supply. Subscapular, circumflex, suprascapular. 
 
 13. Blood-supply. Circumflex, subscapular, dorsalis scapulae, axillary. 
 
 14. Ligamcntous Muscles. (i) Biceps; (2) triceps; (3) supraspinatus ; (4) 
 
428 
 
 PKA CTICAL ANA TOM ) '. 
 
 infraspinatus ; (5) subscapularis ; (6) teres minor ; (7) teres major ; (8) latissimus 
 dorsi ; (9) coraco-brachialis ; (10) pectoralis major ; (i i) deltoid. 
 
 1 . Name the osteological parts concerned in this articulation in any manner. 
 
 (i) The articular surface of the humeral head; (2) the glenoid cavity of the 
 scapular head ; (3) the anatomical neck of the humerus ; (4) the anatomical neck 
 of the scapula ; (5) the greater tuberosity with its three facets ; (6) the lesser 
 tuberosity with one facet ; (7) the surgical neck of the humerus ; (8) the surgi- 
 cal neck of the scapula ; (9) the humeral bicipital groove and its lips ; (10) the 
 supraglenoid tubercle bicipital ; (i i) the infraglenoid tubercle tricipital ; (12) 
 the scapular notch and foramen; (13) the suprascapular notch and foramen ; 
 (14) the fourth scapular angle ; (15) the acromion process of scapula ; (16) the 
 coracoid process of the scapula. 
 
 2. Give the morphology of the coraco-Jutmeral ligament. 
 
 Trapezoid ligament 
 
 Tendon of subscapularis muscle 
 
 Capsule of the acromio-elavicular 
 joint 
 
 Coraco-acromial ligament 
 Coraco-humeral ligament 
 
 Transverse humeral ligament 
 
 Tendon of biceps 
 
 FIG. 297. OUTER VIEW OK THK SHOULDER-JOINT, SHOWING THI. CORACO-HUMERAL AND 
 TRANSVERSE HUMERAL LIGAMENTS. 
 
 It is the divorced tendon of the pectoralis minor muscle, which in primitive 
 man was inserted into the lesser tuberosity of the humerus. 
 
 3. By ichat is tlie capsule of the shoulder-joint lined / 
 
 By synovial membrane. This membrane is also reflected onto the long head 
 of the biceps muscle in its transit of the cavity. 
 
 4. \Vliere is tlic transverse /mineral ligament, and -<chat is its function / 
 
 It stretches from greater to lesser tuberosity, converting the bicipital groove 
 into a canal for the lodgment of the long tendon of origin of the biceps muscle. 
 The canal is lined by a vaginal synovial membrane. 
 
 5. ]\ 'hat is (lie g/enoid ligament / 
 
 A circumferential rim of cartilage whose function seems to be to deepen the 
 cavity for the head of tin: hiimerus. It is attaehed to the capsule, and also to the 
 margin of the glenoid cavity. It is also continuous with the long head of the 
 biceps muscle. 
 
ARTICULA TIONS. LIGAMENTS. 
 
 429 
 
 6. Through what osteological points 'would a fracture of the surgical neck of tlic 
 scapula pass ? 
 
 (i) Through the suprascapular notch ; (2) through the scapular notch ; (3) 
 through the fourth scapular angle or the deepest part of the subscapular fossa. 
 
 Tell where tJie ligaments are found by which the scapula and clavicle arc held 
 together. 
 
 THE SCAPULO-CLAVICULAR UNION. 
 
 1. Between the acromion process of the scapula and the clavicle. 
 
 2. Between the coracoid process and the clavicle. 
 
 3. Between certain given parts of the scapula alone. (Fig. 298.) 
 
 Transverse ligament 
 
 Conoid ligament 
 
 Acromio-clavioular 
 ligament 
 
 Tendon of infra- 
 spinatus and teres 
 minor 
 
 Inferior transverse 
 or spino-glenoid 
 ligament 
 Capsule of shoulder 
 
 FIG. 298. POSTERIOR VIEW OF THE SHOULDER-JOINT, SHOWING ALSO THE ACROMIO- 
 CLAVICULAR JOINT AND THE PROPER LIGAMENTS OF THE SCAPULA. 
 
 THE ACROMIO-CLAVICULAR ARTICULATION. 
 
 1. Class. Diarthrosis, because of capsule, synovia, and motion. 
 
 2. Subdivision. Arthrodia, because of gliding, simple movement. 
 
 3. Technical Name. Acromio-clavicular articulation. 
 
 4. Osteological Units. Clavicle and scapula. 
 
 5. Subdivisional Parts. Acromion and acromial end of clavicle. 
 
 6. Articular Surfaces. Acromial of clavicle, clavicular of acromion. 
 
 7. Basis. A capsule lined by synovial membrane. 
 Subdivisions of Capsule. Superior and inferior, by some authors. 
 Strengthening Bands. None. Purely periosteal. 
 Incorporation of Tendons. None. 
 
 Limitation of Motion by Bone. None. 
 Ligaincntous Muscles. Deltoid and major pectoral. 
 Nerve-supply. The circumflex. 
 14. Blood-supply. Circumflex, acromio-thoracic. 
 
 8 
 
 9- 
 10. 
 1 1. 
 
 12. 
 13 
 
43 
 
 PRACTICAL ANATOMY. 
 
 1 . Describe tlic acromion process. 
 
 It is a projection of bone, a continuation of the scapular spine. It has an 
 upper and an under surface, an inner and an outer border, and a tip. Its inner 
 border articulates near the tip with the clavicle. Its outer border gives origin to 
 the deltoid muscle in part. Its upper surface is occupied by the insertion of the 
 trapezius muscle, by the origin of the deltoid, and by a subcutaneous area between 
 the two. Its under surface is smooth and unoccupied. (Fig. 240.) 
 
 2. Describe the interarticular fibro-cartilage. 
 
 When present, it resembles others of the same class in function and attach- 
 ments. 
 
 Conoid ligament 
 
 Transverse scapular ligament 
 
 Trapezoid ligament 
 
 Coraco-acromial ligament 
 
 Short head of biceps 
 Subscapular tendon 
 
 Capsule of shoulder 
 
 Long tendon of 
 biceps 
 
 FIG. 299. ANTERIOR VIEW OF SHOULDER, SHOWING ALSO CORACO-CLAVICI'LAR AND CORACO- 
 ACROMIAL LIGAMENTS. 
 
 THE COR AGO-CLAVICULAR LIGAMENTS. 
 
 Turn the clavicle upward, having cut the same through the middle third, an< 
 you will see a strong band of ligamentous tissue extending from the clavicle to 
 the coracoid process. This consists of two parts : an anterior and outer part, called 
 the trapezoid ligament ; a posterior and internal portion, called the conoid liga- 
 ment. The action of these ligaments is to prevent upward dislocation of the 
 acromial end of the clavicle in fracture of the bone. 
 
 The intrinsic ligaments of the scapula are : (i) The coraco-acromial ; (2) the 
 transverse scapular (Fig. 299) ; (3) the inferior transverse scapular. (Fig. 298.) 
 
 The coraco-acromial extends from the outer border of the coracoid process 
 by a broad base to the tip of the acromion process. Under it you will find the 
 tendon of the stipraspinatus muscle in a bed of fatty connective tissue. 
 
 The transverse scapular ligament bridges over the suprascapular notch, 
 converting the same into a foramen, terminating externally in the coracoid 
 process. On the ligament lie the suprascapular vessels ; beneath the ligament, in 
 the foramen, you will find the suprascapular nerve. (Fig. 299.) 
 
AR TICULA TIONS. LIGA ME NTS. 43 1 
 
 The inferior scapular ligament extends from the glenoid margin to the 
 spine. Under it pass the infraspinatous divisions of the suprascapular vessels 
 and nerves. (Fig. 249.) 
 
 THE STERNO-CLAVICULAR ARTICULATION. 
 
 1. Class. Diarthrosis, since capsule and motion are present. 
 
 2. Subdivision. Arthrodia simple gliding articular surfaces. 
 
 3. Technical Name. Sterno-clavicular articulation. 
 
 4. Osteological Units. Sternum and clavicle. 
 
 5. Sub divisional Parts. Manubrium and sternal end of clavicle. 
 
 6. Articular Surfaces. Sternal of clavicle, clavicular of sternum. 
 
 7. Basis. A capsule lined by synovial membrane. 
 
 8. Local Subdivisions. Should be none. 
 
 9. Strengthening Bands. None. Periosteal purely. 
 
 10. Incorporated Tendons. None. 
 
 1 1. Bony Limitations. Manubrium and first rib. 
 
 1 2. Nerve-supply. Brachial plexus by nerve to subclavius. 
 
 13. Ligamentous Muscles. Subclavius and sterno-mastoid. 
 
 Rhomboid 
 ligament 
 Anterior 
 sterno- 
 clavieular 
 ligament 
 
 FIG. 300. ANTERIOR VIEW OF STERNO-CLAVICULAR JOINT. 
 
 (The capsule is cut into on the left side to show the interarticular fibro- cartilage dividing the joint 
 
 into two cavities.) 
 
 1 . Name all tlie ligaments of this articulation. 
 
 The capsular, the basis of the joint. The interclavicular binds the clavicles to 
 the sternum. The costo-clavicular, or rhomboid. The interarticular fibro- 
 cartilage. 
 
 2. How many synovial cavities has the articulation ? 
 
 Two, separated from each other by the interarticular fibro-cartilage. This 
 cartilage is attached to the capsule like others of its class, as the temporo-man- 
 dibular and the inconstant acromio-clavicular interarticular fibro-cartilage. 
 
 3. In practical dissection, when yon wish to remove the clavicle, what is the most 
 difficult structure to divide ? 
 
 The costo-clavicular ligament binding the clavicle very firmly to the first rib. 
 
 4. What muscle do you find under the clavicle, and what is its surgical impor- 
 tance ? 
 
 The subclavius muscle, arising in front of the costo-clavicular ligament from 
 the first rib. It is inserted into the middle third of the clavicle on the under sur- 
 face of the bone. In fracture of the clavicle in the middle or outer third, the 
 
43 2 PRACTICAL ANATOMY. 
 
 subclavius depresses the inner segment of the bone, while the weight of the arm 
 elevates the outer fragment. These anatomical facts led up to the empiric prac- 
 tice of elevating the elbow and adjusting the inner to the outer clavicular frag- 
 ments in the treatment of fracture of this bone. 
 
 ELBOW-JOINT. 
 
 1. Class. Diarthrosis, because of free motion and a capsule. 
 
 2. Subdivision. Ginglymus, because of motion in two directions. 
 
 3. Technical Name. Humero-radio-ulnar articulation. 
 
 4. Osteological Units. Humerus, radius, ulna. 
 
 5. Subdivisional Parts. Two humeral condyles, a radial head, an olecranon 
 process, a coronoid process, a greater sigmoid cavity, two condylar ridges, an 
 olecranon fossa, a coronoid fossa, a radial fossa. 
 
 6. Radial and Ulnar Articular Surfaces of Humerus. Humeral surfaces of 
 radius and ulna. The ulnar surface of the humerus is called the trochlea. The 
 radial head of the humerus is called the capitellum. 
 
 7. Basis. A capsule lined by synovial membrane. 
 
 8. Local Subdivisions. Anterior, posterior, internal, and external. 
 
 9. Strengthening Bands. None. 
 
 10. Incorporated Tendons. None. 
 
 1 1. Bone Limitations. Olecranon and coronoid processes, humerus. 
 
 12. Nerve-supply. Ulnar, median, musculo-cutaneous, musculo-spiral. 
 
 13. Blood-supply. From the anastomosis about the joint. 
 
 14. Ligamentous Muscles. Biceps, brachialis anticus, supinator longus or 
 brachio-radialis ; triceps and anconeus ; pronator radii teres, flexor carpi radialis, 
 palmaris longus, flexor sublimis digitorum, flexor carpi ulnaris ; supinator brevis, 
 extensor carpi radialis longior, extensor carpi radialis brevior, extensor communis 
 digitorum, extensor minimi digiti, extensor carpi ulnaris. 
 
 Through -what ivould a fracture immediately above the condyles pass ? 
 Through the external and internal condylar ridges, through the olecranon, 
 radial, and coronoid fossae of the humerus. 
 
 SUPERIOR RADIO-ULNAR ARTICULATION. 
 
 1. Class. Diarthrosis, because of free motion. 
 
 2. Subdivision. Lateral ginglymus, motion in two directions only. 
 
 3. Technical Name. Superior radio-ulnar articulation. 
 
 4. Osteological Units. Radius and ulna. 
 
 5. Subdivisional Parts. Head of radius and lesser sigmoid of ulna. 
 
 6. Articular Surfaces. Radial of ulna, ulnar surface of radius. 
 
 7. Basis. An orbicular capsule lined by synovial membrane. 
 
 8. Local Subdivisions of Capsule. None. 
 
 9. Strengthening Bands of the Orbicular C 'apsule. None. 
 
 10. Incorporated Tendons of Obsolete Muscles. None. 
 
 11. Bony Limitations. The ulna and humerus. 
 
 12. Nerve- and Blood-supply. Same as elbow-joint. 
 
 13. Ligamentous Muscles. Supinator brevis and supinator longus. 
 Xdine (lie muscles inserted in the vicinity of this articulation. 
 
 The biceps into the bicipital tuherosity of the radius. The brachialis anticus 
 into the coronoid process of the ulna. The triceps into the olecranon process 
 of the ulna. 
 
 (i'i-<'C tlic origin and insertion of the orbicular ligament. 
 
 It describes three-fourths of a circle, and is attached to the anterior and pos- 
 terior lips of the lesser sigmoid cavity of the ulna. 
 
A R T1CULA TIONS. LIGAMENTS. 
 
 433 
 
 Locate tlie lesser sig moid cavity. 
 
 It is on the outer part of the ulrfa, at the junction of the olecranon and coro- 
 noid processes ; it is limited in front and behind by the anterior and posterior lips 
 of the cavity. It contains the head of the radius. It is covered by articular 
 cartilage. 
 
 THE INTEROSSEOUS MEMBRANE. 
 
 This you will see extending from the interosseous ridge of the ulna to that of 
 the radius. It is limited above by the ulnar origin of the supinator brevis ; below, 
 
 Capsule of elbow-joint 
 Cushion of fatty tissue 
 
 Membranous tissue joining the 
 orbicular ligament to the neck 
 of the radius 
 
 RADIUS 
 
 Orbicular ligament 
 
 Capsule of elbow 
 
 FIG. 301. ORBICULAR LIGAMENT. 
 (The head of the radius removed to show the membranous connection of this ligament with the radius.) 
 
 Orbicular ligament 
 
 External lateral 
 ligament 
 
 Posterior ligament 
 
 FIG. 302. EXTERNAL VIEW OK THE ELBOW-JOINT. 
 
 by the ulnar sigmoid of the radius. It is a modified form of radio-ulnar perios- 
 teum. It is an intermuscular septum between the flexor and extensor muscles 
 on the forearm. It has a posterior and an anterior surface, a radial and an ulnar 
 attached border. On its anterior surface you will find the origin of a part of the 
 flexor profundus digitorum, and the flexor longus pollicis and pronator quadratus 
 muscles. Between these you will see the anterior interosseous nerve and vessels. 
 
434 
 
 PRA CTICAL ANA TOMY. 
 
 On the posterior surface are the three extensors of the thumb, and the posterior 
 interosseous nerve and vessels. An upper st?ong band of this membrane is called 
 the oblique ligament. (Fig. 303.) 
 
 Upper edge 
 of inter- 
 osseous 
 membrane 
 
 FIG. 303. INTERNAL VIEW OK 
 
 Anterior radio-ulnar 
 ligament 
 
 Internal lateral liga- 
 ment of wrist 
 Flexor carpi uluaris 
 
 External lateral ligament 
 
 of wrist 
 Anterior radio-carpal 
 
 ligament 
 
 Tendon of flexor carpi 
 radialis 
 
 Capsular ligament of first 
 oarpo-metacarpal joint 
 
 FIG. 304. ANTERIOR VIEW OF \\ KISI. 
 
 THE INFERIOR RADIO-ULNAR ARTICULATION. 
 
 1. Class. Diarthrosis, because of free motion and a capsule. 
 
 2. Subdivision. Ginglymus, because of motion in two directions only. 
 
 3. Technical Name. Inferior radio-ulnar articulation ; common, none. 
 
 4. Ostcologieal I 'nits. Radius and ulna. 
 
 5. Snl>tJr t 'isioii(i/ /W/'/.v. Head of ulna, sigmoid of radius. (Fig. 246.) 
 
ARTICULA TIONS. LIGAMENTS. 
 
 435 
 
 6. Articular Surfaces. Ulnar of radius, radial surface of ulna. 
 
 7. Basis. A modified capsule, lined by synovial membrane. 
 
 8. Local Parts of Capsule. An anterior radio-ulnar, posterior radio-ulnar, 
 triangular fibro-cartilage. 
 
 9. Strengthening Bands. None ; periosteal purely. 
 
 10. Incorporated Tendons of Obsolete Muscles. None. 
 
 1 1. Blood-supply. Anterior interosseous and anterior carpal. (Fig. 247.) 
 
 1 2. Nerve-supply. Anterior and posterior interosseous. 
 
 13. Ligamentous Muscles. Pronator quadratus and supinator longus. 
 Locate and give the attachments of the anterior radio-ulnar ligament. 
 
 It is attached to the radio-ulnar triangular fibro-cartilage and styloid process. 
 It is located on the anterior part of the bones. 
 
 Locate and give the attachments of the posterior radio-ulnar ligament. 
 
 It is attached to the radius, ulna, and triangular fibro-cartilage anteriorly 
 and posteriorly. 
 
 Posterior radio-carpal 
 ligament 
 
 Capsule of carpo-meta- 
 carpal joint of thumb 
 
 Posterior radio- 
 ulnar ligament 
 
 Internal lateral 
 ligament of wrist 
 
 FIG. 305. POSTERIOR VIEW OF WRIST. 
 
 THE RADIO-CARPAL ARTICULATION. 
 
 1. Class. Diarthrosis, because of free motion and a capsule. 
 
 2. Subdivision. Condylarthrosis, because rotation on a vertical axis is 
 wanting ; /. t\, there is no axial rotation. 
 
 3. Teclinical Name. Radio-carpal articulation. 
 
 4. Osteological Units. Radius, scaphoid, semilunar, cuneiform, cartilage. 
 
 5. Subdivisional Parts of Units. None. 
 
 6. Articular Surfaces. According to the general rule. 
 
 7. Basis. A modified and highly specialized capsule. 
 
 8. Local Parts of Capsule. Anterior, posterior, internal, external. 
 
 9. Strengthening Bands. None ; purely periosteal. 
 
 10. Incorporated Tendons of Obsolete Muscles. None. 
 
 11. Bony Limitations. Radial and ulnar styloids. 
 
 1 2. Blood-supply. Anterior and posterior carpal arterial arches. 
 
 13. Ligamentous Muscles. (i)The flexors of the carpus, on radius and ulna ; 
 (2) the extensors of the carpus, on radius and ulna ; (3) the sublime and pro- 
 
43 6 
 
 PRACTICAL ANATOMY. 
 
 found digital flexors ; (4) the flexor longus pollicis ; (5) the extensor communis 
 digitorum ; (6) the special extensor of the little finger ; (7) the special extensor 
 of the index finger; (8) the three extensors of the thumb. Total, 14. 
 
 Explain fully tJie most important ligament in the radio-carpal articulation. 
 
 The most important is the triangular fibro-cartilage. It may be described as 
 having : (i) A base, attached to the margin of the radius ; (2) an apex, attached 
 to the fossa at base of ulnar styloid ; (3) an anterior border, attached to radio- 
 
 Synovial sac of the inferior radio- 
 uluar joint 
 
 Synovial sac of the carpus 
 
 Synovial sac, occasionally separate, 
 for the fourth and fifth metacar- 
 pal bones 
 
 Synovial sac of the wrist-joint 
 
 Synovial sac of the carpo- 
 metacarpal joint of the 
 thumb 
 
 Lateral ligaments of the metacarpo- 
 phalangeal. and inter-phalangeal 
 joints 
 
 !'!(;. 306. SYNOYIAI. MKMBRANKS OK \\KIM, HAM>. \M> I-INC.KKS. 
 
 carpal and radio-ulnar ligaments ; (4) a posterior border, attached to the radio- 
 carpal and radio-ulnar ligaments; (5) an upper or ulnar articular surface (con- 
 cave) ; (6) a lower or cuneiform surface (concave). 
 
 1 !<>:,< does tltis cartilage differ from all otlier Jihro-eartiln^es. 
 
 It niters into the formation of two distinct articulations, the inferior radio- 
 ulnar and radio -Carpal, separating them completely. 
 
 /I'//// lioio ninny hones does the end of tlie radius articulate f 
 With the scaphoid and scmilunar. 
 
ARTICULA TIONS. LIGAMENTS. 43 7 
 
 Give tlic attachments of the internal lateral ligament of the radio-carpal articu- 
 lation. 
 
 Its apex is attached to the styloid process of the ulna ; its base to the pisi- 
 form and cuneiform bones, and to the anterior annular ligament. 
 
 Give attachments of the external lateral ligament of the radio-carpal articulation. 
 
 Its apex is attached to the apex of the radial styloid process ; its base to the 
 scaphoid and trapezium. 
 
 Give the attachments of the anterior radio-carpal ligament. 
 
 It is attached above to the radius and anterior radio-ulnar ligament ; below, 
 to the two rows of carpal bones. 
 
 Give the attachments of the posterior radio-carpal ligament. 
 
 It is attached above to radius, styloid, and fibre-cartilage ; below, to the first 
 row of carpal bones. 
 
 Does the synovial cavity of the radio-carpal articulation communicate with the in- 
 ferior radio-ulnar or carpal articulations ? 
 
 No. 
 
 CARPAL ARTICULATIONS. 
 
 How may we consider the carpal articulations ? 
 
 (i) The joints of the first row consisting of four short bones ; (2) the joints 
 of the second row consisting of four short bones; (3) the junction of the two 
 rows called the medio-carpal joint. 
 
 Name the short bones in the first and second rows. 
 
 The scaphoid, semilunar, cuneiform, and pisiform ; trapezium, trapezoid, os 
 magnum, and unciform. 
 
 Name the ligaments of the first row. 
 
 They are all connected by two dorsal and two palmar and two interosseous 
 ligaments to each other, except the pisiform. 
 
 How may the pisiform bone be regarded ? 
 
 It may be regarded as a sesamoid bone developed in the tendon of the flexor 
 carpi ulnaris, and connected by a capsule to the cuneiform bone. 
 
 How are the bones of the second row united ? 
 
 By three dorsal, three palmar, and two interosseous ligaments. The articu- 
 lations of the first and second rows belong to the diarthrodial class and arthrodial 
 subdivision of joints. 
 
 Name the ligaments of the medio-carpal articulation. 
 
 These are the anterior, posterior, medio-carpal, and transverse dorsal ligaments. 
 To dissect this region cut through dorsal ligaments. 
 
 Give the attachments of the anterior annular ligament. 
 
 Internally it is attached to the unciform process of the unciform bone, and the 
 pisiform bone ; externally, to the scaphoid and trapezium. 
 
 How many insertions has the flexor carpi ulnaris ? 
 
 Three : (i) Into the pisiform bone ; (2) into the unciform process of the unci- 
 form bone ; (3) into the base of the fifth metacarpal. 
 
 Trace the tendon of the flexor carpi radialis to its insertion. 
 
 It passes through a groove in the os trapezium, and is inserted into the base 
 of the second metacarpal, sometimes also into the third as well. 
 
 How are the carpo-metacarpal articulations classified ? 
 
 (i) Into an outer, corresponding to the thumb ; (2) four inner, corresponding 
 to the remaining four digits. 
 
 Wliv are they so classified .' 
 
 Because they belong to different subdivisions of the class diarthrosis. The 
 carpo-metacarpal of the thumb is a saddle-shaped arthrodia ; the others are simply 
 arthrodia. 
 
438 
 
 PRACTICAL ANATOMY. 
 
 Name tJic ligaments of the carpo-metacarpal articulation of tlie tJiumb. This is 
 a capsular ligament. 
 
 In this joint are found all the movements except axial rotation. 
 
 Name the ligaments of the four inner carpo-metacarpal articulations. 
 
 They are dorsal, palmar, and interosseous. 
 
 How are these joints supplied witJi nerves / 
 
 By the ulnar median and posterior interosseous. 
 
 How many intcrmetacarpal articulations are t lie re f 
 
 Four ; bound together by dorsal, palmar, and interosseous ligaments. 
 
 How are the heads of the metacarpal bones held together ? 
 
 By transverse ligaments. In front of these ligaments pass the lumbrical 
 muscles, with the digital vessels and nerves ; behind, pass the interossei muscles. 
 
 Here are seen the reflected 
 tendon of the rectus and 
 the triangular ' ilio-tro- 
 ohanterio' band 
 
 Ischio-femoral band 
 This is placed ou the weak 
 portion of the capsule 
 
 FIG. 307. POSTERIOR VIEW OK THE CAPSULE OK THE HII--JOINT. 
 
 The metacarpo-pJialangeal articulations are jive in number. 
 
 Class, diarthrosis ; subdivision, condylarthrosis. The ligaments are lateral and 
 glenoid. The nerves and arteries come from the digital branches. 
 
 Classify the intcrplialangcal articulations. 
 
 They belong to the class diarthrosis ; subdivision, ginglymus. The proper 
 ligaments are lateral and glenoid. Dorsally, the tendon of the extensor com- 
 munis digitorum acts ligamentously ; on the palmar surface, the tendons of the 
 flexors. The articular arteries and nerves come, according to the rule, from the 
 vessels and nerves that supply the muscles that move these joints. 
 
 THE HIP-JOINT. 
 
 1. Class. Diarthrosis ; axial rotation and four angular movements. 
 
 2. Subdivision. Knarthrosis or ball-and-socket. 
 
ARTICULA TIONS. LIGAMENTS. 
 
 439 
 
 3. Technical Name. Femoro-acetabular. 
 
 4. Osteological Units. Femur and os innominatum. 
 
 5. Subdivisional Parts. Ilium, ischium, pubes, and femoral head. 
 
 6. Articular Surfaces. Named according to the rule. 
 
 7. Basis. A capsule lined by synovial membrane. 
 
 8. Local Subdivisions. Ilio-femoral, ischio-femoral, pectineo-femoral. 
 
 9. Strengthening' Bands. Tendino-trochanteric band. 
 
 10. Incorporated Tendon of the Pectineus Muscle (ligamentum teres). 
 
 1 1. Bony Limitations. The brim and circumference of acetabulum. 
 
 12. Nerve-supply. Anterior crural, obturator, great sciatic, sacral plexus. 
 
 13. Blood-supply. Obturator, circumflex, gluteal and sciatic arteries. 
 
 14. Ligamentous Muscles. (i) Sartorius ; (2) rectus femoris ; (3) ilio-psoas ; 
 
 Tendon of rectus pulled up 
 
 Tendino-trochanteric band passing 
 between rectus and vastus externus 
 
 Placed on the weak spot of capsule, 
 which is sometimes perforated to 
 allow the bursa under psoas to com- 
 municate with joint 
 
 Ilio-femoral band 
 
 Pectineo-femoral band 
 
 FIG. 308. ANTERIOR VIEW OK THE CAPSULE OK THE HIP-JOINT. 
 
 (4) pectineus ; (5) gracilis ; (6) adductors longus, brevis, and magnus ; (7) the 
 glutei maximus, medius, and minimus ; (8) the obturators internus and ex- 
 ternus ; (9) the gemelli, superior and inferior; (10) the tensor vaginae femoris ; 
 (i i)'the semitendinosus, biceps, and semimembranosus. 
 
 Name the ligaments of the hip. 
 
 (i) The capsular ligament, the basis of the joint ; (2) the transverse ligament ; 
 (3) the ligamentum teres, an interarticular structure ; (4) the cotyloid, a circum- 
 ferential cartilage. 
 
 What can you say of the capsular ligament / 
 
 It is one of the strongest ligaments in the body. It is attached to the an- 
 terior intertrochanteric line in front ; posteriorly, it is attached to the back of the 
 neck, one-half of an inch above the posterior intertrochanteric line. 
 
440 PRACTICAL ANATOMY. 
 
 What can yon say of the ilio-femoml band / 
 
 This is the strongest band. Its apex is attached below the anterior inferior 
 iliac spine ; its base is attached to the anterior intertrochanteric line. 
 
 Describe t/ic ligamentum teres. 
 
 Externally, it is attached to the lips of the cotyloid notch ; between these 
 extremes, fibres spring from the transverse ligament. Internally, the ligament is 
 attached to the depression in the head of the femur called the tereal. 
 
 Name all the bony parts about the hip-joint. (Fig. 226.) 
 
 The greater and lesser trochanters, the neck of the femur, the anterior and 
 posterior intertrochanteric lines, the anterior inferior spinous process of the ilium, 
 the ilio-pubal eminence and line, the tuber of the ischium, the ischio-pubic ramus. 
 
 THE KNEE-JOINT. 
 
 1. Class. Diarthrosis, because of free movement and constant synovia. 
 
 2. Subdivision. Ginglyinus, because of motion in two directions. 
 
 3. Technical Name. Tibio-femoral articulation. 
 
 4. Osteological Units. Femur, tibia, and patella. 
 
 5. Subdivisional Parts. Femoral condyles, tibial tuberosities. 
 
 6. Articular Surfaces. Named according to general rule. 
 
 7. Basis. A capsule lined by synovial membrane. 
 
 8. Local Subdivisions. Internal, external, anterior, posterior. 
 
 9. Strengthening Bands. Biceps, sartorius, semimembranosus. 
 
 10. Incorporated Tendons. Peroneus longus, adductor magnus. 
 
 1 1. Bony Limitations. Patella, tibia, and femur. 
 
 12. Nerve-supply. Great sciatic, anterior crural, obturator. 
 
 13. Blood-supply. Articular arteries from the internal and external articular 
 branches of the popliteal artery, both above and below the joint ; from the 
 azygos ; from the recurrent branches of both the anterior and posterior tibial 
 arteries ; from the anastomotica femoris. 
 
 14. Ligamentous Muscles. (i) Extensor quadriceps femoris ; (2) gracilis and 
 sartorius ; (3) semitendinosus and semimembranosus and biceps ; (4) gastroc- 
 nemius and plantaris. 
 
 Name all tJic ligaments of the knee-joint. 
 
 (i) The fibrous expansion of the extensors (strengthening bands) ; (2) cap- 
 sular or anterior ligament ; (3) posterior ligament or ligament of Wins- 
 low ; (4) external lateral ligament ; (5) internal lateral ligament ; (6) ligamentum 
 patellae ; (7) anterior crucial ligament ; (8) posterior crucial ligament ; (9) 
 internal semilunar fibro-cartilages ; (10) external semilunar fibro-cartila^es ; 
 (i i) the coronaiy ligament ; (12) the transverse ligament. 
 
 / 1 'liat is the ligamcntnni patella' / 
 
 It is a strong tendon by which the extensors of the leg are inserted into the 
 tubercle of the tibia. Its borders form a guide to the surgeon in injecting and 
 aspirating the cavity of the synovial membrane at the knee. Behind the ten- 
 don, between this and the true capsule, is a mass of fat and a small bursa, re st- 
 ing on the bursal segment of the tubercle of the tibia. In front of the liga- 
 mentum patella- is a large prepatellar bursa, whose enlargement is known as 
 "housemaid's knee." Laterally, the ligamentum patella- is continuous with the 
 fibrous expansion of the extensor muscles of the leg. 
 
 Describe and locate tJic ligament of Winslo-^<. 
 
 It bridges the space between the internal and external lateral ligaments. It 
 has perforations for vessels and nerves. It is strengthened by an aponeurosis 
 of the semimembranosus muscle. It forms part of tin- floor of the popliteal 
 space. On it rest the popliteal vessels. 
 
 
lagamentum teres 
 
 Capsular ligament 
 
 Capaular ligament, cut 
 tyloid ligament 
 
 Capsular ligament 
 
 FIG. 309. HIP-JOINT AFTER DIVIDING THE CAPSULAR LIGAMENT AND DISARTICULATING 
 
 THE FEMUR. 
 
 Aperture leading into the 
 bursa beneath the quadri- 
 ceps extensor 
 
 Attachment of capsular, or 
 anterior ligament to femur 
 
 Fatty tissue within cut edge 
 of ligamentum mucosum 
 
 Anterior crucial ligament 
 
 External semilunar 
 nbro-cartilage 
 
 Coronary ligament 
 
 Posterior crucial ligament 
 
 Internal semilunar 
 nbro-cartilage 
 
 Transverse ligament 
 Coronary ligament 
 
 FIG. 310. ANTERIOR VIEW OF THE INTERNAL LIGAMENTS OF THE KNEE-JOINT. 
 2 9 441 
 
442 
 
 PRACTICAL ANATOMY. 
 
 Describe tlic location, length, and relations of tlic infernal la feral ligament. 
 
 It extends from the inner condyle to the tibia, being about three inches in 
 length. Its outer surface is related to the gracilis, the semimembranosus, and the 
 sartorius muscles ; its deep surface is in relation with the coronary ligament and 
 
 Flantaris 
 Outer head of gastrocnemius 
 
 External lateral ligament: 
 anterior portion 
 
 Posterior part of external 
 lateral ligament 
 Tendon of popliteus 
 
 Tendon of biceps 
 
 Posterior superior tibio- 
 nbular ligament 
 
 Tendon of adductor magnus 
 
 Inner head of 
 
 gastrociiemius 
 
 Tendon of semi-membra- 
 noauB with its slip to 
 thicken the posterior liga- 
 ment 
 
 Internal lateral ligament 
 
 Kit;. 311. POSTERIOR VIEW OK THE KNEE-JOINT. 
 
 Ligamentum patellae 
 
 Transverse ligament 
 
 Anterior crucial 
 
 Internal semilunar flbro- 
 cartilage 
 
 Posterior crucial 
 ligament 
 
 Expansion from quadriceps 
 extensor tendon 
 
 t~ External semilunar flbro- 
 \ \ cartilage 
 
 Tendon of biceps 
 External lateral ligament 
 
 In.. 312. STRUCTURES I.YIM; ON mi Hi \i> <>! IHI TMIIA. (Right knee.) 
 
 semilunar cartilage. This ligament is the divorced Undon of the adductor 
 magnus muscle. 
 
 /'lie external lateral ligament Consists of hoi,' many parts / 
 
 Of two an anterior and a posterior. (I'"ig. 31 I.) The anterior, the longer. 
 
A R TICULA TIONS. LIGAMENTS. 
 
 443 
 
 extends from the tubercle on the outer femoral condyle to the head of the fibula. 
 Beneath this ligament is the popliteus tendon in its synovial sheath. The 
 posterior portion is inserted into the styloid. It binds the popliteus to the 
 outer tuberosity. 
 
 Describe tlie anterior or capsular ligament proper. 
 
 It is thin, and attached to the synovial membrane. It is attached to the 
 femur, patella, popliteus muscle, and internal lateral ligament. 
 
 Locate and give function of the semilunar fibro-cartilages, and mention other 
 members of the same physiological class of ligaments. 
 
 They are two circumferential cartilages resting on the articular facets of the 
 tibia. In mechanics they correspond to a ball-bearing. They deepen the cavity 
 which they surround. The cotyloid of the hip, the glenoids of the shoulder 
 
 Posterior crucial 
 
 lagamentum mucosuin 
 
 Alar ligament 
 
 Alar ligament 
 
 Synovial pouch under tendon 
 of quadriceps extensor 
 
 FIG. 313. ANTERIOR VIEW OF THE KNEE-JOINT, SHOWING THE SYNOVIAL LIGAMENTS. 
 (Anterior portion of capsule with the extensor tendon thrown downward.) 
 
 and of the interphalangeal and metacarpo-phalangeal articulations belong to the 
 same class. 
 
 Name the attachments of the semilunars. (Fig. 312.) 
 
 They are attached loosely to the borders of the tuberosities by the coronary 
 ligament ; to each other, in front, by the transverse ligament ; their extremities are 
 attached to the depressions in front and behind the spine of the tibia. (Fig. 312.) 
 What can yon say of the synovia! membrane of the knee-joint f 
 It is the largest in the body. One part forms a sac beneath the patella ; 
 another extends some distance above the attachment of the capsule above the 
 joint ; it covers all the surface of the crucial ligaments except at two parts. 
 Give the origin and insertion of the crucial ligaments. (Fig. 312.) 
 The anterior crucial is attached to the tibia in front of the spine, and to the 
 
444 PRACTICAL ANATOMY. 
 
 border of the inner facet, and to the inner and back part of the outer condyle. 
 The posterior is attached to the popliteal notch and adjacent structures, and to 
 the outer part of the inner condyle. (Fig. 227.) 
 
 Give synonyms for the crucial ligaments. 
 
 The anterior is called also external ; the posterior is called also internal. 
 
 Define ligaincnta a/aria and ligamentuui inucosum. 
 
 The terms are misnomers. These structures are parts only of the synovial 
 membrane. (See Fig. 313.) 
 
 NOTE. The student should endeavor to make his dissection resemble the 
 cuts, and then exercise his knowledge of osteology by minutely describing all 
 the attachments and relations. Drill of this kind will make him familiar with 
 the text, as well as with the cadaver, and be splendid discipline in cultivating 
 descriptive powers a faculty each one possesses to greater or lesser degree. 
 
 Name, locate, and define the varieties of synovial membrane. 
 
 1. The articular, which is found in all freely movable joints, as the knee 
 and hip. In the foetus it is said this membrane covers the articular surfaces of 
 the cartilage, as well as the interior of the capsule. 
 
 2. The bursal varieties are of two kinds. Mucous bursae are found between 
 the skin and bone, as the prepatellar. Synovial bursae are found between tendons 
 and bone, as about the knee between the ligamentum patellae. 
 
 3. The vaginal kind. This variety will be found surrounding the flexor 
 tendons of the digits, in the hand and foot ; surrounding the long tendon of the 
 biceps in the bicipital canal of the humerus under the transverse ligament of this 
 bone. 
 
 THE TIBIO-FIBULAR UNION. 
 
 1. The superior tibio-fibular articulation has a capsule, an anterior and a 
 posterior tibio-fibular ligament. 
 
 It belongs to the class diarthrosis, because of its constant capsule and syno- 
 via, and to the subdivision arthrodia, because of its gliding movement. 
 
 The synovial cavity of this joint may communicate with the knee. 
 
 The blood-supply comes from the external articular and recurrent tibial. 
 
 The nerve-supply is from the recurrent branch of the external popliteal and 
 the inferior external articular. 
 
 2. The tibio-fibular interosseous membrane is incomplete above for about 
 an inch. The anterior tibial artery passes through here, between the two heads 
 of the tibialis posticus muscle, to the anterior part of the leg. The function of 
 membrane is principally for muscular origin. It has two borders the tibial and 
 the fibular ; two surfaces the anterior and the posterior. The anterior is in 
 relation with the anterior tibial nerve and vessels and with the muscles of the 
 anterior region of the leg. The posterior surface is in relation with the tibialis 
 posticus and the flexor longus hallucis. 
 
 3. The inferior tibio-fibular articulation. (Fig. 317.) 
 Class. Diarthrosis, because of free movement and synovia. 
 Subdivision. Arthrodia, because of a gliding movement. 
 
 The ligtiincnts arc anterior, posterior, transverse, and inferior interosseous, all 
 of which are easily found. The synovial membrane is continuous with that of 
 the ankle-joint. The nerve-supply is from the internal or long saphenous, ante- 
 rior and posterior tibial. The blood-supply is from the peroneal and its ante- 
 rior branch. 
 
 THE ANKLE-JOINT. 
 
 1. (.'/(iss. Diarthrosis, because of a capsule and free movement. 
 
 2. Subdivision. (linglymus, because of movement in two directions. 
 
. / A' T1CULA TIONS. LIGAMENTS. 445 
 
 3. Technical Name. Tibio-fibulo-astragaloid articulation. 
 
 4. Osteological Units. Tibia, fibula, and astragalus. 
 
 5. Snbdivisional Parts. Inner and outer malleoli, astragalus. 
 
 6. Articular Surfaces. Named according to the general rule. 
 
 7. Basis. A capsule lined by a secreting synovial membrane. 
 
 8. Local Subdivisions. Anterior, posterior, internal, external. 
 
 9. Strengthening Bands. None. 
 
 10. Incorporated Tendons of Obsolete Muscles. None. 
 
 1 1. Bony Limitations. Malleoli of tibia and fibula, and the os calcis. 
 
 1 2. Nerve-supply. Anterior and posterior tibial, and internal saphenous. 
 
 13. Blood-supply. Anterior and posterior tibial and peroneal arteries. 
 
 14. Ligamentous Muscles. Tibialis anticus, extensor proprius hallucis, ex- 
 tensor communis digitorum, peroneus tertius, peroneus longus, peroneus brevis, 
 tibialis posticus, flexor longus digitorum, flexor longus hallucis, and the three 
 muscles inserted by the tendo Achillis. 
 
 Give the attachments of the anterior ligament of the ankle-joint. (Fig. 317.) 
 
 It is attached above to the malleoli of the tibia and fibula, to the tibia, and 
 to the anterior inferior tibio-fibular ligament ; below, it is attached to the neck of 
 the astragalus. 
 
 Give the relations of the anterior ligament of the ankle-joint. 
 
 Anteriorly, it is in relation with the anterior tibial nerve and vessels, and all 
 the muscles of the front of the leg ; posteriorly, with the synovial membrane 
 and a fatty mass of connective tissue. 
 
 Give the attachments of the posterior ligament of the ankle-joint. (Fig. 317.) 
 
 It is attached above to the external malleolus, the tibia, and the posterior in- 
 ferior tibio-fibular ligament ; below, to the posterior surface of the astragalus. 
 
 Describe the internal lateral ligament. (Fig. 318.) 
 
 It is called the deltoid ligament. It is attached above to the lower border 
 of the internal malleolus ; below, to the astragalus, the sustentaculum tali, and 
 the calcaneo-astragaloid ligament. Externally, this ligament is in relation with 
 the tibialis posticus and flexor longus digitorum muscles ; internally, with 
 the synovial membrane. 
 
 Describe the external ligament of the ankle-joint. (Fig. 317.) 
 
 It has three fasciculi, or bundles, two of which are horizontal and one ver- 
 tical. The anterior bundle extends from the fibular malleolus to the astragalus 
 in front ; the posterior bundle from the malleolus to the posterior surface of 
 the astragalus ; the middle bundle from the malleolus to the outer surface of 
 the os calcis. 
 
 Give the relations of the external ligament of the ankle-joint. 
 
 Externally, with the tendons of the peroneus longus and peroneus brevis 
 muscles ; internally, with the synovial membrane. 
 
 Describe the movements in tJic ankle-joint. 
 
 This joint is a hinge ; hence it has movement in two directions, as in ordinary 
 walking. If, however, you extend the foot fully, you will find considerable 
 lateral motion. Flex the foot to the fullest extent, and no lateral motion is pos- 
 sible. Study the diameters of the articular part of the astragalus, and also the 
 diameters of the intermalleolar slot, in which the astragalus works, and you will 
 see reason for free lateral mobility of the foot in extreme extension, in the differ- 
 ence in these diameters. 
 
 What can you say of the synovial membrane of the ankle-joint .' 
 
 It lines the ligaments, and is said by Morris to secrete more synovia than 
 any other synovial membrane. 
 
446 
 
 PRACTICAL ANATOMY. 
 
 THE TARSUS TARSAL ARTICULATIONS. 
 
 Define tlic i^ord tarsus, and name its Jwnwlogue in the upper extremity. 
 The word means instep ; its homologue is the carpus, which means wrist. 
 
 POSTERO-INFERIOR SURFACE OF THE 
 CALCANEUM 
 
 Abductor minimi digit! 
 Abductor oasis metatarsi quinti 
 
 Accesaoriua (outer head) 
 
 Flexor brevis halluci 
 Abductor ossis metatarsi quinti 
 
 Flexor brevis minimi digit! 
 
 Adductor hallucis 
 Third plantar iuterosseous 
 
 Second plantar interosseous 
 First plantar interosseous 
 
 Flexor brevis minimi digit! 
 
 Abductor brevis minimi 
 digiti 
 
 Third plantar 
 interosseous 
 
 Second plantar 
 interosseous 
 
 First plantar interosseous 
 
 Flexor brevis digitorum 
 Flexor loiiguu digitorum 
 
 Abductor halluois 
 Flexor brevis digitorum 
 
 Accessorius i inner head) 
 
 Tibialis posticus 
 
 Tibialis anticua 
 Peroneus lonRU 
 
 Abductor hallucis 
 Flexor brevia halluoit 
 
 (inner portion) 
 Flexor brevis hallucis 
 
 (outer portion) 
 Adductor hnllnois 
 Trausversus pedis 
 
 Flexor longus hallucii 
 
 l-ii.. 314. Till, I.ii i FOOT. (I'lantar surface. ) 
 (Study tlic insertion and location of tendons on tliis and compare your dissection therewith.) 
 
 To ?c /tut class do tlic tar sal hones belong .' To icliat is their shape adapted / 
 They are classified as short bones ; tlu-ir function is to combine gre 
 strength with slight motion. 
 
ARTICULA TIONS. LIGAMENTS. 
 
 447 
 
 Xante the bones of the tarsus and indieate tltcir fanciful derivation. 
 
 (i) Astragalus, the dice bone; (2) calcaneum, the heel bone; (3) scaphoid, 
 
 Tendo Acliillis 
 
 Extensor brevis 
 digitorum 
 
 Extensor longus 
 halluoia 
 
 Extensor brevis 
 digitorum 
 
 Peroneus brevis 
 Peroneus tertius 
 
 METATARSUS 
 
 FIRST PHALANX 
 
 SECOND PHALANX 
 THIRD PHALANX 
 
 Extensor longus digitorum 
 
 Fu;. 315. THE LEFT FOOT. (Dorsal surface.) 
 (Study origin and insertion of muscles on this figure and compare with your dissection.") 
 
 resembling a boat; (4) cuboid, like a cube; (5) cuneiform, like a wedge. The 
 ancient shepherds threw dice. The bones they used were from the sheep, hence 
 our name, astragalus, or dice bone. 
 
448 
 
 PRACTICAL ANATOMY. 
 
 Describe tJie astragalus. (Fig. 315.) 
 
 This bone has (i) a head, which articulates with the scaphoid bone ; (2) a 
 neck, by which the head is joined to the body of the bone ; (3) a body, which 
 has superior, inferior, internal, external, and posterior surfaces. 
 
 Give the importance of each surface of the astragalus. 
 
 (i) The superior surface articulates with the tibia ; (2) the external surface 
 articulates with the fibular malleolus ; (3) the internal surface articulates with 
 the tibial malleolus; (4) the inferior surface articulates with the calcaneum ; (5) 
 the posterior surface has a groove for the flexor longus hallucis. 
 
 Describe the calcaneum or Jic el-bone. (Fig. 315.) 
 
 This bone has six surfaces anterior, posterior, superior, inferior, internal, 
 and external. 
 
 Give the importance of each surface. 
 
 (i) The anterior surface articulates with the cuboid bone ; (2) the posterior 
 surface has the tendo Achillis attached to it ; (3) the external surface has two 
 peroneal grooves and a tubercle between them ; (4) the internal surface has the 
 
 FIG. 316. SECTION TO SHOW TMK SYNOVIAI. CAVITIES OK THK FOOT. 
 
 i. Posterior calcaneo-astragaloid. 
 4. Tarsal. 
 
 2. Calcaneo-cuboid. 
 5. Cubo-metatarsal. 
 
 3. Anterior calcaneo-astragalo-scaplioid. 
 6. First inetatarso-cuneiform. 
 
 sustentaculum tali and a groove ; (5) the inferior surface has the three important 
 tubercles ; (6) the superior surface has an astragaloid articular surface. 
 
 Name and give importance of the tubercles of tlie calcaneum. (Fig. 314.) 
 
 (i) The inner tubercle gives origin to the abductor hallucis, the flexor brevis 
 digitorum, and the abductor minimi digiti ; (2) the outer tubercle gives origin 
 to the abductor minimi digiti, and to the inconstant abductor ossis metatarsi 
 quinti ; (3) the anterior tubercle gives attachment to the short plantar or cal- 
 caneo-cuboid ligament. 
 
 Describe the scaphoid bone. (Fig. 316.) 
 
 This bone articulates posteriorly with the head of the astragalus ; anteriorly 
 with the three cuneiform bones. The superior, inferior, and external surfaces art- 
 rough, for the attachment of ligaments. The internal surface has the tuberosity, 
 into which is inserted the tibialis posticus muscle. 
 
 Describe the cuboid bone. (Fig. 316.) 
 
 It has six surfaces : (i) The anterior articulates with the bases of the fourth 
 and fifth tnrtatarsals ; (j)the posterior articulates with the calcaneum; (3) tin- 
 internal articulates with the scaphoid (sometimes) and external cuneiform ; (4) 
 the superior is rough, for attachment of ligaments ; (5) the inferior has a groove 
 
 
ARTICULA TIONS. LIGAMENTS. 
 
 449 
 
 for the peroneus longus ; (6) the outer is almost negative, and is continuous with 
 the inferior surface. 
 
 Can you say anything more about the inferior surface of tJic cuboid bone f 
 
 Yes ; it has a ridge behind the peroneal groove, for the attachment of the 
 long calcaneo-cuboid ligament ; this ridge terminates externally in the sesamoid 
 articular surface, which articulates with the peroneal sesamoid bone, in the 
 tendon of the peroneus longus. The flexor brevis hallucis also derives its origin 
 on this surface of the bone. (Fig. 314.) 
 
 Describe t/ie surfaces of the internal cuneiform. 
 
 (i) The internal surface has the insertion of the tibialis anticus ; (2) the exter- 
 nal articulates with the second metatarsal and middle cuneiform ; (3) the anterior 
 
 Antero-inferior tibio-flbular 
 ligament 
 
 Anterior ligament of ankle-joint 
 
 Outer extremity of the 
 
 mterosseous ligament 
 
 External calcaneo- 
 scaphoid ligament 
 
 Postero-inferior tibio- 
 flbular ligament 
 
 Fasciculus of posterior 
 ligament of ankle 
 
 Posterior fasciculus of 
 external lateral ligament 
 
 ligament 
 Internal calcaneo-cuboid 
 
 Dorsal External Middle fasciculus of external lateral 
 alcaneo- calcaneo- ligament of the ankle 
 
 cuboid astragaloid 
 ligament 
 
 FIG. 317. EXTERNAL VIEW OF THE LIGAMENTS OF THE FOOT AND ANKLE. 
 
 articulates with the first metatarsal bone ; (4) the posterior articulates with the 
 scaphoid bone ; (5) the inferior has the insertion of the tibialis posticus. 
 
 Describe the surfaces of the middle cuneiform. 
 
 (i) The anterior articulates with the second metatarsal bone ; (2) the posterior 
 articulates with the scaphoid bone ; (3) the internal articulates with the internal 
 cuneiform bone ; (4) the external articulates with the external cuneiform bone ; 
 (5) the superior surface is rough, for ligamentous attachment; (6) into the in- 
 ferior surface is inserted the tibialis posticus muscle and ligaments. 
 
 Describe the surfaces of the external cuneiform. 
 
 (i) The anterior articulates with the third metatarsal ; (2) the posterior with 
 the scaphoid bone ; (3) the internal with the middle cuneiform bone ; (4) the 
 external with the fourth metatarsal and cuboid bone ; (5) the inferior is for 
 tibialis posticus and ligaments ; (6) the superior is for ligamentous attachment. 
 
Internal lateral 
 ligament 
 
 Inferior cal- 
 
 ooneo-scaphoid 
 
 ligament 
 
 Short plantar ligament Long plantar ligament 
 
 FIG. 318. INNER VIEW OK THE ANKLK AND THE TARSUS, SHOWING THE GROOVE FOR THE 
 TENDON OF THE TIBIAI.IS POSTICUS. 
 
 Long plantar or long Inferior 
 calcaneo-cuboid ligament 
 
 Tendon of peroneus longus 
 
 GROOVE FOR FLEXOR LONGUS 
 HALLUCIS 
 
 Inferior caloaneo-acaphoid 
 
 ligament 
 
 Short plantar or short interior 
 calcaneo-cuboid ligament 
 
 TUBERCLE OF SCAPHOID 
 
 INTERNAL CUNEIFORM 
 
 Insertion of peroueus 
 longus 
 
 1'IC. 319. Lll.AMIM^ 01 IHI Soil (,| Tin.; I.KI I 
 450 
 
AR T1CULA TWNS. L IGAMENTS. 45 1 
 
 Give comparative size of the cuneiform bones. 
 
 The internal cuneiform is the largest bone ; the middle cuneiform is the 
 smallest bone ; the external cuneiform is intermediate in size. 
 
 Name the principal muscular-traction points in and about the tarsus, and indi- 
 cate the muscle attached thereto. 
 
 (i) Calcaneum for the tendo Achillis ; (2) calcaneum for the abductor hallucis 
 and flexor brevis digitorum ; (3) calcaneum for the abductor minimi digiti and 
 accessorius ; (4) calcaneum for the extensor brevis digitorum ; (5) sustentaculum 
 tali groove for the tendon of flexor longus hallucis ; (6) the tuberosity of the 
 scaphoid bone for the tibialis posticus ; (7) the internal cuneiform for the tibialis 
 anticus ; (8) the first metacarpal for the peroneus tertius and tibialis anticus ; 
 (9) the fifth metatarsal for the peroneus brevis ; (10) cuboidal groove for the ten- 
 don of peroneus longus. 
 
 Locate the medio-tarsal articulation by limitation, and name its ligaments. 
 
 This joint is limited posteriorly by the calcaneum and astragalus ; anteriorly, 
 by the scaphoid and cuboid. (Fig. 316.) The ligaments are : (i) The external 
 calcaneo-scaphoid ; (2) the inferior calcaneo-scaphoid ; (3) the astragalo-scaphoid 
 ligament ; (4) the internal or interosseous calcaneo-cuboid ligament ; (5) the long 
 inferior calcaneo-cuboid ligament; (6) the short inferior calcaneo-cuboid liga- 
 ment ; (7) the dorsal calcaneo-cuboid ligament. 
 
 Give the attachments of the long inferior calcaneo-cuboid ligament and the 
 common name for the same. (Fig. 319.) 
 
 It is also called the long plantar ligament. It is attached to the whole infe- 
 rior surface of the calcaneum behind ; to the cuboid and bases of the meta- 
 tarsals in front. 
 
 Can yon mention any other important fact in regard to the long plantar 
 ligament / 
 
 Yes ; it completes the canal for the peroneus longus muscle, and also gives 
 origin to the adductor hallucis and the flexor brevis minimi digiti. (Fig. 319.) 
 
 Give the attachments of the short inferior calcaneo-cuboid ligament and its 
 common name. 
 
 It is called the short plantar ligament. It is attached to the under surfaces 
 of the calcaneum and cuboid. (Fig. 319.) 
 
 From what source does the medio-tarsal joint receive its nerve-supply ? 
 
 From the outer division of the anterior tibial, the musculo-cutaneous, and 
 the external plantar nerves. 
 
 From ivhat source does the medio-tarsal joint receive its blood-supply ? 
 
 From the anterior tibial, the dorsalis pedis, and the internal and external 
 plantar arteries. 
 
 What class and subdivision does the medio-tarsal articidation belong in ? 
 
 (i) The astragalo-scaphoid joint is diarthrosis by class, and enarthrodia by 
 subdivision ; (2) the calcaneo-cuboid is diarthrosis by class, and saddle arthrodia 
 by subdivision. 
 
 Name the ligaments of the calcanco-astragaloid articulation. 
 
 (i) The external calcaneo-astragaloid ligament; (2) the internal calcaneo- 
 astragaloid ligament ; (3) the posterior calcaneo-astragaloid ligament ; (4) the 
 interosseous calcaneo-astragaloid ligament. 
 
 Locate the interosseous ligament. 
 
 It extends from the calcaneum to the astragalus, connecting the parallel 
 oblique grooves of these two bones. 
 
 Describe the scapho-cuneiform articulation. 
 
 Class. Diarthrosis, because of free movement and a capsule. 
 
 Subdivision. Arthrodia, because of a gliding movement. 
 
 Ligaments. Dorsal, plantar, and internal. 
 
452 
 
 PRACTICAL ANATOMY. 
 
 Describe the intercuneiform articulations. 
 
 Class. Diarthrosis, because of free movement and a capsule. 
 
 Subdivision. Arthrodia, because of a gliding movement. 
 
 Ligaments. Dorsal, plantar, and interosseous. 
 
 Blood-supply. Metatarsal and plantar arteries. 
 
 Nerve-supply. Anterior tibial and plantar nerves. 
 
 Describe the tarsometatarsal articulations. 
 
 Class. Diarthrosis, because of free movement and a capsule. 
 
 Subdivision. Arthrodia, because of a gliding movement. 
 
 Ligaments. Dorsal, palmar, and interosseous. 
 
 Nerve-supply. Anterior tibial and plantar nerves. 
 
 Posterior ligament of ankle- 
 joint 
 
 Posterior part of the internal 
 lateral ligament 
 
 The lower part of the inter- 
 oaseous membrane 
 
 Transverse ligament of inferior 
 tibio-nbular joint 
 
 Posterior fasciculus of external 
 lateral ligament 
 
 Middle fasciculus of external 
 lateral ligament 
 
 FlG. 320. LUIAMENTS SEEN FROM THE BACK OF THE ANKLE-JOINT. 
 
 Describe the intermetatarsal articulations. 
 Class. Diarthrosis, because of free movement and a capsule. 
 Subdivision. Arthrodia, because of a gliding movement. 
 Ligaments, Dorsal, plantar, and interosseous. 
 
 //ow arc the heads of the nictatarsal bones connected / 
 By rather strong, short, transverse ligaments. 
 Describe the metatarso-phalangeal articulations. 
 ( '/tiss. Diarthrosis, because of free movement and a capsule. 
 Subdivision. Condylarthrosis, because of no axial rotation. 
 Ligaments. Lateral, dorsal, plantar, sesamoul. 
 Liganicntons Muscles. Flexors and extensors of the digits. 
 Describe the interphalangeal articulations. 
 
 Class. Diarthrosis. because of free movrnu-nt. 
 
 Subdivision. (iinglymus, because of motion in two directions. 
 
ARTICULA TIONS. LIGAMENTS. 
 
 Ligaments. Laterals, dorsals, and glenoids. 
 
 Ligamentous Muscles. Flexors and extensors of the digits. 
 
 Nerve-supply. Internal and external plantar nerves. 
 
 453 
 
 FIG. 321. RIGHT INNOMINATE BONE, EXTERNAL ASPECT. 
 
 Superior border, or crest. 2. Anterior superior iliac spine. 3. Posterior superior iliac spine. 4,4,4. 
 Superior curved line. 5,5- Inferior curved line. 6. Surface between inferior curved line and 
 acetabulum. 7. Anterior inferior iliac spine. 8. Anterior interspinous notch. 9. Posterior inferior 
 iliac spine. 10. Posterior interspinous notch. II. Spine of ischium. 12. Great sacro-sciatic notch. 
 13. Acetabulum. 14. Fundus of acetabulum. 15,15. Circumference of acetabulum. 16. Cotyloid 
 notch. 17. Spine of pubes. 18. Horizontal branch of pubes. 19. Descending branch of pubes. 
 20,20. Ischium. 21. Groove for tendon of obturator externus muscle. 22. Obturator foramen. 
 
 P. LAC. it E.SAL. 
 
 FIG. 322. PELVIS, ANTEKO SUPKKIOR VIEW, SUPERIOR STRAIT. 
 
 1,1. Internal iliac fossae. 2,2. Iliac crests. 3,3- Anterior superior iliac spines. 4,4. Anterior inferior 
 iliac spines. 5,5. Ilio-pectineal eminences. 6,6. Horizontal branches of pubes. 7.7. Bodies and 
 symphysis of pubes. 8, 8. Acetabula. 9, 9. Tuberosities of iscbia. 10, 10. Ascending rami of 
 ischium. II, II. Descending rami of pubes. 12, 12. Spines of ischia. 13, 13 Posterior wall of 
 pelvic cavity. 14, 14. Sacro-iliac symphyses. 15. Sacro-vertebral angle. 16, 16. Superior strait. 
 
 THE PELVIS ITS ARTICULATIONS AND LIGAMENTS. 
 
 The bones of the pelvis are the sacrum, coccyx, and ossa innominata. The 
 pelvis articulates with the lumbar part of the vertebral column, and with the 
 head of the femur. We m;iy then classify the articulations, for purposes of con- 
 venience, as (i) intrinsic, where the articulation is between pelvic bones ; (2) ex- 
 trinsic, where the articulation is between pelvic bones and bones not pelvic. 
 
PRACTICAL ANATOMY. 
 
 The intrinsic pelvic articulations arc : 
 
 (i) The sacro-iliac, between the sacrum and ilium ; (2) the sacro-sciatic, 
 between the sacrum and ischium ; (3) the interpubic, between the pubic bones ; 
 (4) the sacro-coccygeal, between the sacrum and coccyx. 
 
 The extrinsic ligaments are : 
 
 (i) The sacro-lumbar, between the sacrum and the last vertebra of the lum- 
 bar region ; (2) the femoro-innominate group of ligaments. 
 
 Name tlie ostcological points of interest in and about the pelvis. 
 
 (i) Symphysis pubis, between the pubic bones; (2) pubic crest, limited by 
 the angle and spine of pubis ; (3) ilio-pubic line, limited by the spine and ilio- 
 pubic eminence ; (4) the ilio-pubic eminence, at the junction of pubis and ilium ; 
 
 FIG. 323. FEMUR, POSTERIOR ASPECT. 
 1,1. Linea aspera. 2,2. External division. 3. Internal division. 4,4. Inferior divisions. 5. Iliad. 
 6. Depression for attachment of round ligament. 7. Neck. 8. Great trochanter. 9. liigital or 
 trochameric fossa. IO. Lesser trochanter. II. Outer coiulyle. 12. Inner condyle. 13. Inter 
 condyloid notch. 14. Outer tuberosity. 15. Inner tuberosity. 
 
 (5) the iliac crest, limited by the superior iliac spines, anterior and posterior; (6) 
 the acetabulum, at the junction of the ilium, ischium, and pubes ; (7) the fossa 
 acetabuli, the non-articular part of the acetabulum ; (8) the cotyloid notch, an 
 interruption in the acetabular brim; (9) the lesser sacro-sciatic notch, between 
 the ischial tuber and spine ; (10) the ischial spine, between the greater and les.ser 
 sciatic notches ; (i i) the tub'er of the ischium, one of the grand divisions of the 
 ischium ; (12) the ischio-pubic ramus, between the pubes and ischium ; (13) the 
 obturator foramen, bounded by the pubes and ischium; (14) the pelvic inlet, 
 between the true and false pelvis ; (15) the subpubic arcade, between tin- ischio- 
 pubic rami ; (16) the anterior superior iliac spine, for the insertion of Poupart's 
 ligament ; (17) the anterior inferior iliac spine, lor the oiigin of the straight head 
 of the reetus; (18) the anterior interspinous notch, between the anterior iliac 
 
ARTICULA TIONS. LIGAMENTS. 
 
 455 
 
 spines ; (19) the posterior iliac spines, superior and inferior ; (20) the promontory 
 of the sacrum ; (21) the alas of the sacrum, consisting of transverse and costal 
 elemental parts ; (22) the anterior sacral foramina, for the anterior sacral nerves ; 
 (23) the sacro-iliac synchondrosis, right and left; (24) the greater and lesser 
 
 Superior pubio ligament 
 
 Inferior pubic ligament 
 
 FIG. 324. ANTERIOR VIEW OF THE SYMPHYSIS Puuis (FEMALE, SHOWING GREATER WIDTH 
 
 BETWEEN THE BONES). 
 
 Inferior pubio ligament 
 
 FIG. 325. POSTERIOR VIEW OF THE SYMPHYSIS PUBIS, SHOWING THE BACKWARD PROJECTION OK 
 THE SYMPHYSIAI. SUBSTANCE AND THE DECUSSATION OF THE FIBRES FROM THE INFERIOR 
 PUBIC LIGAMENT. 
 
 Superior pubic ligament 
 
 Inferior pubic ligament 
 
 FIG. 326. ANTERIOR VIEW OF THE SYMPHYSIS Pi ms (MALE) SHOWING DECUSSATION OF THK 
 FIBRES OF THE ANTERIOR LIGAMENT. 
 
 trochanters of the femur ; (25) the anterior and posterior intertrochanteric lines ; 
 (26) the digital or trochanteric fossa ; (27) the superior and inferior cervical 
 tubercles of the femur. 
 
45 6 
 
 PRACTICAL ANATOMY. 
 
 Symphysis Pubis : 
 
 Class. Amphiarthrosis, because of union by cartilage and slight motion. 
 
 Ostcological lUements. The bodies of the two pubic bones. 
 
 Ligaments. Anterior, posterior, superior, inferior, and interosseous cartilage. 
 
 Is there any difference bcticeen this joint in tlic tico sexes? 
 
 The joint is shorter and broader in the female than in the male. (Fig. 324.) 
 
 Is the nerve-supply of the sympliy sis pubis ice// understood / 
 
 No ; but it probably is derived from the ilio-inguinal, ilio-hypogastric, and 
 
 internal pudic nerves. 
 
 From ivhat source does this articulation derive its blood-supply / 
 
 From the internal pudic, the obturator, deep epigastric, internal circumflex, 
 
 iliac, and external pudic arteries. 
 
 Foramen for last 
 
 lumbar nerve 
 Intervertebral body 
 between last lum- 
 bar and first sacral 
 vertebrae 
 
 Foramen for anterior primary branch of fourth 
 lumbar nerve 
 
 The ilio-lumbar 
 ligament 
 
 The sacro-lumbar 
 ligament 
 
 Superior sacro-iliac 
 ligament 
 
 Anterior sacro-iliac 
 ligament 
 
 Great aacro- sciatic 
 ligament 
 
 Lesser sacro-sciatic 
 ligament 
 
 Fiu. 327. ANTERIOR VIEW OK 1111. 
 
 Wlial influence has pregnancy on t/ic interosseous cartilage beticeen the pubic 
 bones ? 
 
 The cartilage becomes softer and the blood-supply more abundant. 
 
 Is there any special difference in tlic hiterosseons cartilage in /lie male and 
 female f 
 
 It is thicker in the female than in the male. 
 
 \Vliat is sympliysotomy or sympliysiotomy .' 
 
 Cutting through the pubic symphysis to increase tin- conjugate diameters of 
 the pelvic canal. In this obstetric operation all the ligaments of the symphysis 
 pubis are cut. 
 
 Sacro-iliac Articulation and Its Ligaments : 
 
 Class. AmphiarthroMs, bones united by cartilage and slight motion. 
 
ARTICULATIONS. LIGAMENTS. 457 
 
 Osteological Units. The sacrum and ilium. 
 
 Snbdii'isional Parts. Auricular surfaces of the sacrum and ilium. 
 
 Nerve-supply. Superior gluteal, sacral plexus, first and second sacral nerves. 
 
 Blood-supply. Gluteal, ilio-lumbar, and lateral sacral arteries. 
 
 Morphologically, what is that fart of the sacrum that articulates with the 
 auricular part of the ilium / 
 
 It is the result of a peculiar modification of the costal elements of the first 
 three sacral vertebrae. 
 
 Name and locate the ligaments of this articulation. 
 
 (i) Anterior sacro-iliac, from pelvic brim to greater sacro-sciatic foramen ; 
 (2) posterior sacro-iliac, from back of sacrum to iliac crest ; (3) superior sacro- 
 iliac, from sacral base to iliac fossa ; (4) inferior sacro-iliac, from sacrum to pos- 
 terior iliac spine ; (5) interosseous ligament is between the two spines. 
 
 The function of the sacro-iliac ligaments is to bind the sacrum to the ilium. 
 
 Falciform process of the 
 great ligament 
 
 . Tendon of biceps muscle, continuous with 
 the great sacro-sciatic ligament 
 
 FIG. 328. SACRO-SCIATIC LIGAMENTS. (Posterior view. ) 
 
 They are purely of periosteal derivation. The plate of cartilage between the 
 bones may become ossified, just as the ligaments of the vertebral column some- 
 times do. Occasionally, a distinct synovial cavity is found in the center of this 
 cartilage. 
 
 Sacro-ischiatic Ligaments : 
 
 Hozv many ligaments unite the sacrum and ischium ? (Fig. 328.) 
 
 Two ; the common name for these is sacro-sciatic, which is a contraction of 
 the true word for purposes of euphony. The common names are : (i) Greater 
 or posterior sacro-sciatic ligament; (2) lesser or anterior sacro-sciatic ligament. 
 
 Locate the greater ligament. 
 
 The greater or posterior sacro-sciatic ligament is attached above to the mar- 
 gin of the sacrum and coccyx and to the posterior inferior iliac spine ; below to 
 the inner margin of the tuber of the ischium and ascending ramus of the ischium 
 for about two inches. 
 3 
 
PRACTICAL ANATOMY. 
 
 \\liat is the special name for the tu'o inches of t lie greater sacro-sciatic ligament 
 that is prolonged on to the inner margin of the ascending rannts of the iscluum f 
 
 It is called the falciform ligament. (Fig. 328.) This ligament unites with 
 the obturator fascia to strengthen Alcock's canal, in which canal are located the 
 internal pudic nerve and vessels. 
 
 What are the functions of the greater sacro-sciatic ligament, exclusive of its 
 special part the falciform ligament / 
 
 It gives partial origin to the gluteus maximus muscle, and converts the lesser 
 sacro-sciatic notch into a foramen. 
 
 Name the structures that pass through the lesser sacro-sciatic foramen. 
 
 (i) The tendon of the obturator muscle and its nerve; (2) the internal 
 pudic nerve and vessels. 
 
 Locate the lesser sacro-sciatic ligament. 
 
 The lesser or anterior sacro-sciatic ligament is attached above to the margin 
 
 Superior saero-iliac 
 ligament 
 
 Anterior eacro-iliac 
 
 ligament 
 
 Inferior saoro-iliac 
 ligament 
 
 Small sacro-sciatic 
 ligament 
 
 Great sacro-sciatic 
 ligament 
 
 Fi<;. 329. VERTICAL ANTKRO-POSTKRIOK SECTION OK Tin: I'KI.VIS. 
 
 of the sacrum and coccyx ; below, to the spine of the ischium. This ligament 
 converts the greater sacro-sciatic notch into a foramen. 
 
 Name structures transmitted hy the greater sacro-sciatic foramen. 
 
 (l) The pyriformis muscle, above which pass out the glutcal nerve ami 
 vessels, and below which muscle pass out the sciatic vessels and nerves, the 
 internal pudic nerve and vessels, and the branch of the sacral plexus that sup- 
 plies the obturator muscle. 
 
 \arne all (he structures that /cave tlie pelvis through the greater sacro-sciatic 
 foramen, cross (he iscl/ial spine, and reenter the pelvis through the lesser sacro- 
 sciatic foramen. 
 
 (l) The branch of the sacral plexus to the obturator interims; (2} the 
 internal pudic nerve ; (3) the internal pudic vessels. 
 
 \\7iat becomes of these structures on reentering the pelvis / 
 
A R T1CULA TIONS. LIGAMENTS. 
 
 459 
 
 They enter Alcock's canal, which is a delamination of the obturator fascia 
 strengthened by the falciform ligament, a special part of the greater sacro-sciatic 
 ligament. 
 
 2 2 
 
 1 
 
 FIG. 330. COCCYX, ANTERIOR ASPECT. 
 
 I. Base. 2, 2. Cornua. 3. Second coccygeal vertebra. 4. Third coccygeal vertebra. 5. Fourth coc- 
 cygeal vertebra. 6. Fifth coccygeal vertebra. 
 
 Fie';. 331. VERTEBRAL COLUMN, LATERAL ASPHT. 
 
 1-7. Cervical vertebrae. 8-19. Dorsal vertel>ne. 20-24. Lumbar vertebra'. A, A. Spinous processes. 
 B, B. Articular facets of transverse processes of first ten dorsal vertebras. C. Auricular surface of 
 sacrum. I). Foramina in transverse processes of cervical vertebrae. 
 
 The Sacro-coccygeal Articulation and Ligaments : 
 
 1 . Class. Amphiarthrosis, bones united by cartilage. 
 
 2. Osteological Units. The sacrum and coccyx. 
 
 3. Subdivisio nal Parts. Sacral and coccygeal cornua. 
 
 4. Nerve-supply. The fourth, fifth sacral, and coccygeal nerves. 
 
460 
 
 PRACTICAL ANATOMY. 
 
 5. Blood-supply. Middle sacral and lateral sacral artery. 
 
 6. Ligaments. Anterior sacro-coccygeal ligament, on the front of bodies ; 
 posterior sacro-coccygeal ligament, on posterior part of bodies ; supracornual 
 ligament, a prolongation of the supraspinous ligament ; intertransverse ligament, 
 analogous to the intertransverse ligaments of the true vertebrae ; intervertebral 
 substance of jelly-like cartilage. 
 
 The Sacro- vertebral Articulation and its Ligaments : 
 
 1. Class. Amphiarthrosis between the bodies of the vertebrae. 
 
 2. Class. Diarthrosis between the articular processes. 
 
 3. Subdivision. Arthrodia, because of a gliding movement. 
 
 4. Osteological Units. Same as between two vertebrae. 
 
 5. Subdivisional Parts. Same as in juxtaposition of vertebras. 
 
 Lateral expanded portion 
 
 Median longitudinal band 
 
 Fic.. 332. POSTERIOR COMMON LIGAMENT OK THE SPINE. (Thoracic region.) 
 (Pedicles cut through, and posterior arches of vertebra removed.) 
 
 6. Nerve-supply. Fourth and fifth lumbar and sympathetic. 
 
 7. Blood-supply. Lateral sacral, last lumbar, ilio-lumbar. 
 
 8. Special Name. Sacro-vertebral angle. 
 
 9. Ligaments of Sacro-vertebral Articulation. (i) Prolongation down wan 
 of the ligaments of the vertebral column under the same name. They may be 
 modified to some extent to meet the particular demands of a special region ; for 
 this modification you can account philosophically : growth is the correlative of 
 function. (2) Sacro-lumbar ligament, triangular in shape. (3) Ilio-lumbar liga- 
 ment, triangular in shape. 
 
 THE VERTEBRAL COLUMN AND ITS Lu; AMEN r>. 
 Of what is the vertebral column composed .' 
 Of thirty-three irregular bones, called vertebra.-. They arc classified as true 
 
AR TICULA TIONS. LIGAMENTS. 46 1 
 
 and false vertebrae. The false vertebrae, nine in number, five sacral and four 
 coccygeal, make by their fusion the sacrum and coccyx. 
 
 Name tlie regions of tlie vertebral column and give sonic reasons for a regional 
 subdivision of tJic column. 
 
 The vertebral regions and the number of bones in each are : (i) Cervical 
 reg'on, containing seven bones ; (2) dorsal or thoracic region, containing twelve 
 boius ; (3) lumbar region, containing five bones ; (4) sacro-coccygeal region, con- 
 taining nine bones. Subdivision of the vertebral column into regions depends on 
 a difference in form of the bones, while this difference in the form depends on the 
 function of the region in which the bones are located ; growth predetermines 
 form, and is the correlative of function. 
 
 What is tlie natural arrangement of adjacent vertebne to cadi other / 
 
 They are in juxtaposition that is, one next to another, with parallelism of 
 
 Portion of ligamen- 
 tum subflavum re- 
 moved to show the 
 articular cavity 
 
 Iiigamentum 
 subflavum 
 
 1/11 ; - 333- LlGAMENTA SUBFLAVA IN THE LUMBAR REGION. 
 
 homologous parts. Thus, this arrangement among the bones of the vertebral 
 column gives a logical basis for studying the ligaments of the column, since we 
 find : Juxtaposition of bodies ; juxtaposition of pedicles ; juxtaposition of lam- 
 inae ; juxtaposition of articular processes ; juxtaposition of spinous processes ; 
 juxtaposition of transverse processes. 
 
 Wliat is t/ie function of the bodies or centra, and by u'hat ligaments are they 
 held together .' 
 
 They give solidity and strength to the column. The ligaments of the bodies 
 or centra are the anterior common, posterior common, and intercentral discs of 
 fibro-cartilage. Their union forms an amphiarthrodial articulation, since bone is 
 united to bone by cartilage with limited motion. 
 
 Give the function and relations of tlie pedicles. 
 
 The pedicles support the neural arch. Above and below them are found 
 the intervertebral notches, which are converted into intervertebral foramina when 
 
462 
 
 PRACTICAL ANATOMY. 
 
 the vertebrae are in juxtaposition. (Fig. 335.) These intervertebral foramina 
 transmit the spinal nerves and blood-vessels. 
 
 Give the function of the lainiiue, name tJieir proper ligaments, and tell wherein 
 these ligaments differ liistologically from all otliers of the vertebral column. 
 
 CERVICAL 
 VERTEBRA 
 
 COSTAL PROCESS 
 
 TRANSVERSE PROCESS 
 COSTO-TRANSVERSE FORAMEN 
 
 NEURO-CENTRAL SUTURE 
 CERVICAL RIB 
 
 THORACIC 
 VERTEBRA 
 
 TRANSVERSE PROCESS 
 COSTO-TRANSVERSE FORAMEN 
 
 NEURO-CENTRAL SUTURE 
 RIB 
 
 TRANSVERSE PROCESS 
 LUMBAR RIB 
 
 NEURO-CENTRAL SUTURE 
 COSTAL PROCESS 
 
 I'K;. 334. MoKI'IlOLOCY I'l Till'. TKANSVKKSK AND A KTH T I.A K l'R X 'l-l- >. 
 
 The laminae unite posteriorly to enclose the neural canal. They are bound 
 together by the interlaminar ligaments. These are composed of yellow elastic 
 connective tissue, hence they are called the ligament. i subllava. The term sub- 
 flava means yellowish. 
 
AR TICULA 776LV.V. LIGAMEXTS. 
 
 463 
 
 Give the function of the articular processes and tell illicit kind of joints tlicv 
 form when in juxtaposition. 
 
 The articular processes, by their union, make the vertebral column a concrete 
 whole, the separate parts of which column move or turn on each other. They 
 form diarthrodial articulations of the arthrodial subdivision. The basis of the 
 joint is a capsule lined by synovial membrane. 
 
 Give the function of the transverse processes and explain their serial morphology 
 in the four regions of the column. 
 
 The transverse processes are for the attachment of ligaments, muscles, and 
 either fully developed ribs, or rudimentary ones, called costal elements. The 
 simplest series is in the thoracic region. Here we find a transverse process articu- 
 lating with a rib in such a manner as to leave a space bounded by a rib, transverse 
 process, and pedicle. This space is a vascular opening, and is called a costo- 
 
 The interspinoua 
 ligament 
 
 The supraspinoua 
 ligament 
 
 FIG. 335. THE INTERSPINOUS AND SUPRASPINOUS LIGAMENTS IN THE LUMBAR REGION. 
 
 transverse space. The extremes of the column show this costo-transverse space : 
 a well-formed vertebral canal in the cervical region ; a mere collection of small 
 foramina in the lumbar region ; a depression transmitting a few small vessels in 
 the sacrum, between the costal and the transverse element of the ala of this bone. 
 (Fig. 334.) In the cervical region the rudimentary rib obtains as the anterior 
 tubercle ; in the thoracic region the costal portion is maximal a rib ; in the 
 lumbar region, the transverse process is suppressed and the costal element is 
 very large ; in the sacral region the costal elements of the first three sacral 
 vertebrae are modified to form the auricular part of the sacrum, for articulation 
 with the ilium. 
 
 In view of the great importance of the subject of the serial morphology ot 
 the vertebrae in your dissections, I here introduce figure 334, which will illustrate 
 the foregoing, leaving the subject of morphology for the student to read up in 
 Morris. 
 
 Give the function of the spinons processes and name their ligaments. 
 
4 6 4 
 
 PRACTICAL ANATOMY. 
 
 They are for the attachment of muscles and ligaments. Their ligaments are 
 periosteal, and are named interspinous and supraspinous. (Fig. 335.) 
 
 What is the ligaincntmn nucluz ? 
 
 Literally, the ligament of the nape of the neck. This is a septum of con- 
 nective tissue between the muscles of the back of the neck. Its attachments are 
 the external occipital protuberance (Fig. 338) and the spines of the cervical ver- 
 tebrae. It is rudimentary in man impossible of demonstration in practical 
 anatomy, except as a very feeble intermuscular connective tissue ; not being 
 demonstrable even, in my experience, as an intermuscular septum, such as we 
 find between the peronei muscles and those on the front part of the leg. 
 
 Describe the atlas. 
 
 This is the first of the cervical series of vertebrae. It consists of an anterior 
 
 Vertical portion of crucial 
 
 ligament 
 Central odontoid ligament 
 
 Lateral odontoid ligaments 
 
 Transverse portion of 
 crucial ligament 
 Accessory band of atlanto- 
 azoidean capsules 
 Atlanto-azoidean joint 
 
 Oocipito-cervioal or cervico-basilar 
 ligament 
 
 Posterior common ligament 
 
 FIG. 336. VERTICAL TRANSVERSE SECTION OF THE SPINAL COLUMN AND THE OCCIPITAL I><M 
 
 TO SHOW LIGAMENTS. 
 
 (The cervico-basilar (l), though shown as a distinct stratum, is really the deeper part of 
 the posterior common ligament (2).) 
 
 arch, a posterior arch, and two lateral masses. Morphologically, its divorced or 
 dismembered body obtains as the odontoid process of the axis. 
 
 Give composition of the lateral mass. 
 
 The lateral mass consists of (i) a superior articular process that articulates 
 with the occipital condyle ; (2) an inferior articular process that articulates with 
 the axis ; (3) costal process a rudimentary rib ; (4) a transverse process for 
 muscular attachment; (5) a costotransverse foramen for the vertebral artery; 
 (6) tubercles for attachment of the transverse liganu nt. 
 
 \Vhat do YOU find at the junction of the lateral mass and the posterior arch / 
 
 A groove for the lodgement of the vertebral artery. 
 
 \\ liat is peculiar about tlie relation of the articular processes of the axis and 
 atlas to (lie spinal nerves f 
 
 In these vertebrae the nerves issue behind the articular processes ; the remain- 
 ing spinal nerves issue in front of the articular facets or processes. 
 
ARTICULA TIONS. LIGAMENTS. 
 
 465 
 
 SEVENTH CERVICAL VERTEBRA, POSTERO- 
 
 SUPERIOR VIEW. 
 
 I. Body. 2, 2. Transverse processes. 3, 3. An- 
 terior or costal roots of transverse processes. 4, 4. 
 Foramina for vertebral arteries. 5, 5. Superior 
 articular processes. 6, 6. Inferior articular pro- 
 cesses. 7, 7- Laminae. 8. Spinous process. 9. 
 Spinal foramen. 
 
 DORSAL VERTEBRA, ANTEROSUPERIOR VIEW. 
 I. Anterior surface. 2. Vertebral foramen. 3. 
 Spinous process. 4, 4. Transverse processes. 
 
 5, 5. Articular surfaces for tubercles of ribs. 
 
 6, 6. Superior articular processes. 7, 7. Pedi- 
 cles. 
 
 FIRST DORSAL VERTEBRA, 
 
 LATERAL VIEW. 
 I. Superior surface of body. 2, 2. 
 Semilunar processes. 3. Artic- 
 ular facet for bead of first rib. 
 4. Demi- facet for head of second 
 rib. 5. Superior articular pro- 
 cess. 6, 6. Inferior articular 
 processes. 7. Transverse pro- 
 cess. 8. Articular facet for 
 tubercle of first rib. 9. Spin- 
 ous process. 
 
 ELEVENTH DORSAL VERTEBRA, 
 LATERAL VIEW. 
 
 I. Articular facet for head of 
 eleventh rib. 2. Transverse 
 process. 3. Superior tubercle 
 of transverse process. 4. In- 
 ferior and anterior tubercle. 
 5. Inferior and posterior tuber- 
 cle. 6. Superior articular pro- 
 cess. 7. Inferior articular pro- 
 cess. 8. Spinous process. 
 
 FIG. 337. 
 
 TWELFTH DORSAL VERTEBRA, 
 LATERAL VIEW. 
 
 I. Articular facet for head of 
 twelfth rib. 2. Transverse pro- 
 cess. , 3. Superior and poste- 
 rior tubercle of transverse pro- 
 cess. 4. Inferior and posterior 
 tubercle. 5. Inferior and an- 
 terior tubercle. 6. Superior 
 articular process. 7, 7. Infe- 
 rior articular processes. 8. 
 Spinous process. 
 
 FIG. 338. OCCIPITAL BONE, POSTERO-INFERIOR VIEW. 
 
 I, Basilar process. 2. Foramen magnum. 3,3. Posterior condyloid foramina. 4. Crest. 5. External 
 occipital protuberance. 6, 6. Condyles. 7, 7. Jugular processes. 8, 8. Jugular fossaj. 
 
4 66 
 
 PRACTICAL ANATOMY. 
 
 Occipito- 
 
 atlantal 
 
 capsular 
 
 ligament 
 
 The anterior oblique 
 or lateral oceipito- 
 atlantal ligament 
 
 Atlanto-axoidean 
 capsular ligament 
 
 Capsular ligaments of 
 articular processes 
 between axis and 
 the third, the third 
 and fourth, and the 
 fourth and fifth cer- 
 vical vertebrae 
 
 Continuation of 
 the anterior 
 common liga- 
 ment of the 
 vertebral 
 column 
 
 Anterior oceipi- 
 to-atlantal 
 ligament 
 
 Anterior atlanto- 
 axoidean ligament 
 
 BODY OF AXIS 
 
 Short vertebral 
 ligament 
 
 Anterior common 
 ligament 
 
 FIG. 339. ANTERIOR VIEW OF THE UPPER KND OK THE SPINE. 
 
 The interartioular 
 ligament 
 
 The superior or anterior 
 costo-tranaverse ligaments 
 
 The stellate ligament 
 
 Fro. MO- SIIO\VIN<; THE ANIIKIHK COMMON I.ICAMKNT OK THE SPINE, AND THE CONNECTION 
 
 OK THE RlliS \VITII I III Yl K I I 1 
 
A R TICUL A 77 6LA 'S. L I GA ME NTS. 
 
 467 
 
 \Vliat is peculiar about the axis / 
 
 The odontoid process, the dissociated body of the atlas, is fused to the axis. 
 Xatne the ligaments that bind the axis to the atlas. 
 These ligaments have to do with two distinct classifications : 
 
 -ri i , i ,, . , f Class. Diarthrosis. 
 
 1. 1 he lateral atlanto-axoidean ,,..... ,. 
 
 (_ Subdivision. Arthrodia. 
 
 ^, . , f Class. Diarthrosis. 
 
 2. 1 he central atlanto-axoidean ...... 
 
 ( Subdivision. 1 rochoides. 
 
 The ligaments are of periosteal derivation, called: (i) Anterior atlanto- 
 axoidean ; (2) posterior atlanto-axoidean ; (3) two capsular ligaments lined by 
 
 Left lateral 
 odontoid 
 ligament 
 
 Transverse ligament 
 
 Inner part of capsular ligament 
 of occipito-atlantal j oint 
 
 Posterior oeeipito-atlantal 
 ligament 
 
 Descending portion of crucial 
 ligament 
 
 Posterior atlanto-axoidean 
 ligament 
 
 Interspinous ligament 
 
 Ligamentum subflavum 
 
 Central odontoid 
 
 ligament 
 
 Anterior occipito- 
 atlantal ligament 
 
 Atlanto-odontoid 
 synovial sac 
 
 Anterior atlanto- 
 axoidean ligament 
 
 FIG. 341. VERTICAL ANTERO-POSTERIOR SECTION OF SPINAL COLUMN THROUGH MEDIAN 
 
 LINE, SHOWING LIGAMENTS. 
 
 synovial membrane ; (4) the transverse ligament extending between the tuber- 
 cles of the lateral masses ; (5) the atlanto-odontoid capsular ligament. 
 
 THE ATLANTO-OCCIPITAL ARTICULATION AND LIGAMENTS. 
 
 1. Class. Diarthrosis, because of free movement and synovia. 
 
 2. Subdivision. Double condylarthrosis. 
 
 3. Technical Name. Occipito-atlantal, or atlanto-occipital. 
 
 4. Osteological Units. Occipital bone and atlas. 
 
 5. Subdivisions. Condyles of occipital bone and lateral masses of atlas. 
 
4 68 
 
 PRACTICAL ANATOMY. 
 
 6. Nerve-supply. Anterior division of the suboccipital nerve. 
 
 7. Blood-supply. The vertebral and ascending pbaiyngeal arteries. 
 
 8. Ligaments of Atlanta-occipital Articulation. ( i ) Anterior occipito-atlantal ; 
 (2) posterior occipito-atlantal ; (3) two capsular ; (4) two anterior oblique. 
 
 THE OCCIPITO-AXOID ARTICULATION AND LIGAMENTS. 
 
 1. The occipito-cervical. 
 
 2. The crucial. 
 
 3. Two lateral odontoid or check. 
 
 4. The central odontoid or suspensory. 
 
 For detailed description of these ligaments the student is referred to 
 " Morris' Anatomy." 
 
 Atlanto-axoid- 
 ean capsular 
 ligament 
 
 Occipito-carvl- 
 cal ligament, 
 i.e., the deep 
 stratum of the 
 posterior com- 
 mon vertebral 
 ligament 
 
 Transverse process of atlas 
 
 FIG. 342. THE SUPERFICIAL LAYER OF THE POSTERIOR COMMON VERTEBRAL LIGAMENT HAS I-I-.KN 
 REMOVED TO SHOW ITS DEEP OR SHORT P'lBRES. THESE DEEP FIBRES FORM THE OCC1PITO- 
 CERVICAL LIGAMENT. 
 
 ARTICULATION OF THE Rius WITH THE VERTEBR.I . 
 
 1. Class. Diarthrosis, because of free movement, and a capsule, 
 
 2. Subdivision. Condylarthrosis, because of no axial rotation. 
 
 3. Osteological Units. Vertebrae and ribs. 
 
 4. Subdivisions. Head and tubercle of rib ; body and transverse process. 
 
 5. Tcclinical Xanics. Costocentral joints ; costotransverse joints. 
 
 6. Basis of Joint. A capsule lined by a synovial membrane. 
 
 Tin. BONY THORAX AND ITS INTRINSIC LIGAMENTS. 
 
 The bony thorax, plus certain soft parts, as ligaments, fascia-, muscles, and 
 skin, is a cavity for the protection of the major organs of respiration and circu- 
 lation. Geometrical analysis of the thorax shows it to have : 
 
 i. An 'f/V.r, formed by the manubrium, first rib, first thoracic vertebra. 
 
ARTICULA TIONS. LIGAMENTS. 
 
 469 
 
 FIG. 343. RIBS OF LEFT SIDE, POSTERIOR ASPECT. 
 
 1-12. Anterior extremities of twelve ribs of left side. 13, 13. Internal surface. 14,14. External surface. 
 15. Head of first rib. 16. Mead of second rib. 17. Head of third rib. 18, 18. Heads of ribs from 
 fourth to ninth. 19. Head of tenth rib. 20, 20. Heads of eleventh and twelfth ribs. 21, 21. Necks 
 of ribs. 22. Tubercle of first rib. 23. Articular facet of tubercle of second rib. 24,24. Articular 
 facets of tubercles of ribs from third to ninth. 25. Articular facet for tubercle of tenth rib. 26, 26. 
 Angles of ribs. 
 
 FIG. 344. THORAX, ANTERIOR VIEW. 
 
 I. Manubrium sterni. 2. Gladiolus. 3. Ensiform cartilage or xiphoid appendix. 4. Circumference of 
 apex of thorax. 5. Circumference of base. 6. First rib. 7. Second rib. 8,8. Third, fourth, fifth, 
 sixth, and seventh ribs. 9. Eighth, ninth, and tenth ribs. 10. Eleventh and twelfth ribs, n, n. 
 Costal cartilages. 
 
470 
 
 PR A CT1CAL ANA TOM \ '. 
 
 2. The base, formed by the musculo-aponeurotic diaphragm. 
 
 3. An anterior wall, formed by the sternum and costal chondra or cartilages. 
 
 4. A posterior wall, formed by the thoracic vertebrae and the ribs to the angle. 
 
 5. Lateral walls, formed by the rib from angle to costo-chondral joint. 
 There are twelve ribs on each side twenty-four ribs in the typical human 
 
 thorax. Each rib articulates with the vertebral column posteriorly ; the seven 
 upper ribs articulate in front with the sternum, being called, on this account, true 
 ribs. Of the five lower ribs, three have their ventral end secured in this manner : 
 the eighth is attached to the cartilage of the seventh, the ninth to the cartilage 
 of the eighth, the tenth to the cartilage of the ninth rib. The ventral ends of the 
 eleventh and twelfth ribs are free, /. e., unattached, and are called floating. 
 A typical rib, the seventh, should be studied systematically as to : 
 
 1. A head, which has two facets and a horizontal crest. 
 
 2. A neck, which intervenes between the head and the tubercle. 
 
 3. Tubercle, which consists of an articular and a non-articular part. 
 
 4. An angle, the place where the rib bends in two directions. 
 
 5. The Shaft. This has two surfaces and two borders. 
 
 6. The outer surface is for the attachment of muscles. 
 
 SpinouB process of seventh 
 cervical vertebra 
 
 Capsular ligament of first 
 oosto-central joint 
 
 Capaular ligament of the flrst costo-trans- 
 verse joint 
 
 FIG. 345. THK CAI-SULAK I.ICAMKMS OF THE COSTO-VERTEBRAI. JOINTS. 
 
 7. The inner surface, has the subcostal groove for nerve and vessels. 
 
 8. The superior border, which is thick and rounded. 
 
 9. An inferior border, which is sharp and thin. 
 
 10. The subcostal groove lodges the intercostal vessels and nerves. 
 
 Give tlic rule for the articular part of the head of a rib. 
 
 There are two facets, separated by a hori/.ontal ridge. The ridge is for the 
 attachment of the interosseous ligament between the rib and the intercentral 
 disc of fibre-cartilage. 
 
 1 1 'hat practical observation can be made regard in flic lower articular facet on 
 (lie head of a rib / 
 
 This one is the larger of the two, as a rule, and articulates with the thoracic 
 vertebra which corresponds to it in number from above down. The upper i^ 
 the smaller, and articulates with the vertebra next above. 
 
 Arc there anr c.vccptions to the rule of costal facets on the heads of ribs / 
 
 Yes. As exceptions, may be mentioned the first, tenth, eleventh, and twelfth 
 ribs, each of which has one facet only on its head, as a rule. 
 
 Does the rib articulate with the vertebral column at any other point ! If so. 
 explain fully tlic rule. 
 
ARTICULA riONS. LIGAMENTS. 47 1 
 
 The rule is, the articular part of the costal tubercle articulates with the trans- 
 verse process of the lower of the two vertebrae with which the head of the 
 rib articulates ; thus, the first articulates with the first, the second with the 
 second, and the third with the third. 
 
 Are there any exceptions to tlie rule governing tlie articulation of transverse pro- 
 cesses and articular parts of costal tubercles f 
 
 Yes ; the eleventh and twelfth ribs do not articulate with the transverse 
 processes. 
 
 Enumerate tlie articulations of the ribs with the vertebra. 
 
 (i) Costocentral, between heads of ribs and bodies of vertebrae; (2) costo- 
 transverse, between tubercles of ribs and transverse processes. 
 
 COSTOCENTRAL ARTICULATION LIGAMENTS. 
 
 1. Class. Diarthrosis, because of capsule and free movement. 
 
 2. Subdivision. Condylarthrosis, there being absent axial rotation. 
 
 3. Osteological Units. A rib and a vertebra. 
 
 4. Subdivisionai Parts. Head of a rib, centrum, and cartilage. 
 
 Anterior costo-central 
 or stellate ligament 
 
 Costo-central synovial 
 sac 
 
 Laminar portion of inter- 
 vertebral disc 
 
 Central pulpy portion of inter- 
 vertebral disc 
 
 Middle eqsto-trans- 
 verse ligament 
 
 Costo-transverse synovial sao 
 
 Posterior costo-transverse 
 ligament 
 
 FIG. 346. HORIZONTAL SECTION THROUGH THE INTERVKRTEBRAL Disc AND RIBS. 
 
 5. Basis. A capsule lined by synovial membrane. 
 
 6. Subdivisions. Interarticular and costocentral or stellate ligaments. 
 From what point to what point does the interarticular ligament extend / 
 From the interarticular cartilage to the horizontal ridge on the head of the 
 
 rib, between the articular surfaces of the same. 
 
 From wJiat point to wliat point does the stellate ligament extend / 
 
 From the front of the head of a rib, externally, to the bodies and cartilage 
 with which the head articulates. 
 
 Of liow many parts does tlie articulation between the head of the rib and the 
 centrum consist / 
 
 This cavity is divided into two distinct parts by the interarticular ligament. 
 
 COSTOTRANSVERSE ARTICULATION LlGAMENTS. 
 
 Class. Diarthrosis, because of free motion and a capsule. 
 Subdivision. Arthrodia, because motion is simple and gliding. 
 Osteological Units. A rib and a vertebra. 
 
472 PRACTICAL ANATOMY. 
 
 Subdivisions. Vertebral transverse process and tubercle of a rib. 
 Basis. A capsule lined by synovial membrane. 
 Accessory Ligaments. Middle, superior, posterior, costotransverse. 
 Locate the middle costotransverse ligament. 
 
 
 FOR FIRST RIB 
 
 An interarticular 
 ligament 
 
 SECOND RIB 
 
 The plate of flbro- 
 cartilage between 
 manubrium and 
 meso -sternum 
 
 SEVENTH RIB 
 
 Interohondral 
 capaular ligament 
 
 Fic. 347. '1'iiK STERNUM. 
 (Left side, showing ligaments; right side, the synovial cavities.) 
 
 It is between the back of the neck ot the rib and the front of the transverse 
 process. It is called the costotransverse interosseous ligament. 
 Locate tlie posterior costotransverse ligament. 
 
 It extends from the non-articular part of the tubercle of the rib to the tip of 
 
 the trunsvrrsr prore^. 
 
 Locate ///( superior costotran.^'ersc ligament. 
 
VEINS. 
 
 473 
 
 It extends from the crest of the neck of the rib to the lower border of the 
 transverse process of the vertebra next above. 
 Have all the costal heads capsules ? 
 
 No ; the eleventh and twelfth have none, their union being fibrous. 
 The anterior part of the thorax has the following articulations : 
 
 1. Intersternal, binding sternal ligaments together. 
 
 2. Costo-chondral, binding the ribs to their cartilages. 
 
 3. Chondro-sternal, binding the costal cartilages to the sternum. 
 
 4. IntercJwndral, binding the sixth, seventh, eighth, ninth, and tenth costal 
 cartilages together. 
 
 The superior intersternal articulation is an ainphiartJirodial. joint. 
 
 The manubrium and gladiolus are bound together by an anterior and a. poste- 
 rior common sternal ligament and by an interosseus fibro-cartilage. This ridge or 
 junction may be considered valuable in physical diagnosis as a guide to counting 
 the ribs, since it corresponds to the cartilage of the second rib. 
 
 The inferior intersternal articulation is between the gladiolus and eusifonti parts 
 of the stern n in. 
 
 By this union these two pieces form a synarthrodial joint. 
 
 THE CHONDRO-STERNAL ARTICULATION. 
 
 Wherein does the articulation of the first rib differ from the others in its articu- 
 lation with the sternum / 
 
 It is synarthrodial ; the others are diarthrodial, -the hinge or ginglymoid 
 variety. 
 
 Name the ligaments of the chondro-sternal joints. 
 
 1. Anterior chondro-sternal. 
 
 2. Posterior chondro-sternal. 
 
 3. Superior chondro-sternal. 
 
 4. Inferior chondro-sternal. 
 
 lixplain the nerve-supply of the intrinsic thoracic joints. 
 
 (i) The costocentral is supplied by the intercostal nerves ; (2) the costotrans- 
 verse is supplied by intercostal nerves ; (3) the chondro-sternal is supplied by the 
 intercostals. 
 
 SOME INTERESTING FACTS ABOUT VEINS. 
 
 Veins have more extensive anastomoses than arteries. 
 
 Veins carry blood toward the heart ; arteries from the heart. 
 
 Pulmonary veins return aerated blood from the lungs. 
 
 Systemic veins return CO 2 laden blood from the body general. 
 
 Veins are arbitrarily classed as superficial and deep. 
 
 Systemic veins terminate in the superior and inferior venae cavee. 
 
 Superficial veins are located in the superficial fascia. 
 
 Superficial veins communicate with deep veins through deep fascia. 
 
 Deep veins accompany arteries in one and the same sheath. 
 
 The portal vein takes blood from abdominal digestive organs to liver. 
 
 Visceral veins usually take the name of the organ they drain. 
 
 Deep veins below the elbow and knee are called venae comites. 
 
 The larger arteries are attended by one vein only. 
 
 Veins collapse when empty ; arteries remain open. 
 
 Superficial veins have thicker walls than deep veins. 
 
474 PRACTICAL ANATOMY. 
 
 Veins are stronger than arteries proportionate to their thickness. 
 
 The walls of veins arc thinner than those of corresponding arteries. 
 
 The following veins do not accompany arteries : The large veins from bone ; 
 veins from the skull and spinal canal ; the hepatic veins these latter take all 
 blood from the liver to the ascending vena cava. 
 
 The veins in the lower are thicker than those in the upper extremity. 
 
 Some veins have semilunar valves formed by the inner coat. 
 
 The following veins have no valves : The facial, angular, Vesalian, and oph- 
 thalmic ; the intracranial veins and dural sinuses ; the hepatic, renal, spermatic, 
 ovarian, and uterine ; the superior and inferior venae cavae and veins of bone ; 
 the veins of the whole portal system. 
 
 All veins have nutrient or trophic vessels called vasa vasorum. 
 
 Tlie rule governing the relation of veins to arteries is as follows : Above the 
 diaphragm veins are anterior to their arteries ; below the diaphragm, veins are 
 behind their arteries, where they are not on the same plane. Exception to the 
 rule, the renal vessels. 
 
 Name the veins of the head and neck and indicate any points of special or prac- 
 tical importance in connection therewith. 
 
 The occipital vein (Fig. 18) is the principal vein of the posterior region of 
 the scalp. It perforates the trapezius muscle and is tributary to the deep cervi- 
 cal vein. It communicates by an emissary with the lateral sinus by the mastoid 
 foramen. This may explain the rationale of the empiric practice of counterirri- 
 tation in the region of the mastoid. 
 
 The common temporal vein (Fig. 18) communicates with the deep temporal 
 plexus of veins by the deep temporal vein. Infection of the region of the scalp, 
 drained by tributaries of this vein, may reach the cavernous sinus via the deep 
 temporal vein, the pterygoid plexus, and the Vesalian vein. In the parotid gland 
 this vein unites with the internal maxillary to form the temporo-maxillary vein. 
 
 The facial vein (Fig. 18) corresponds in distribution to its companion artery. 
 Near the angle of the jaw it will be seen to communicate with the external jug- 
 ular vein. The vein is tributary to the internal jugular below the jaw; the sub- 
 maxillary gland, the digastric and stylo-hyoid muscles, and the hypoglossal nerve 
 (Fig. 31) intervening between the vein and its artery in this locality. The most 
 important tributary of this vein is the angular, which communicates with the 
 ophthalmic vein. Infection may reach the cavernous sinus via the angular 
 vein. (See p. 151.) 
 
 The external jugular vein (Fig. 18) is the cervical continuation of the tem- 
 poro-maxillary vein. It perforates the deep cervical fascia behind the middle of 
 the clavicle, and opens into the subclavian or into the internal jugular vein. The 
 special feature of this vein is its inability to collapse in the region of the clavicle. 
 The deep cervical fascia prevents collapse. This inability to collapse renders 
 puncture of the external jugular vein liable to the admission of air. 
 
 The internal maxillary vein is the companion of the artery bearing the 
 same name. This vein returns blood from the deep parts of the face, the muscles 
 of maturation, tin- teeth, and the greater part of the dura mater. The veins from 
 these regions form a plexus called the pterygoid. This plexus is between the 
 temporal and external pterygoid muscles, around the latter muscle, and on the 
 inner surface of the internal pterygoid muscle. The internal maxillary vein 
 proper begins at this plexus. It unites with the temporal vein in the parotid 
 -land to form the temporo-maxillary vein. (See p. 151.) 
 
 The pterygoid plexus communicates with the cavernous sinus via the 
 vein of Ves.ilius ; hence infection anywhere in the region of the radicals of the 
 internal maxiHarv vein may reach tin- dural sinuses in the same way. 
 
 The internal jugular vein (Fig. ;, i) he-ins at the ju-ular foramen. It is in 
 
VEINS. 
 
 475 
 
 direct continuation with the lateral sinus. It conveys all the blood from the 
 brain that is distributed to this organ by the circle of Willis. This internal jugu- 
 lar vein, by its confluence with the subclavian vein, forms the innominate on 
 each side. In the neck the vein accompanies the internal carotid and common 
 carotid arteries, in the upper and lower parts respectively. At the jugular fora- 
 men the vein is in relation with the ninth, tenth, and eleventh cranial nerves, 
 which also emerge from this jugular foramen. This vein has a pair of valves two 
 inches above its terminus. 
 
 THE INNOMINATE VEINS. 
 
 Explain fully tlie innominate or brachio-ceplialic veins on the right and left sides. 
 
 These veins are formed by the confluence of the subclavian and internal 
 jugular veins. (Fig. 150.) The left innominate is much the longer of the 
 two. It crosses all the branches of the second part of the arch of the aorta, 
 both pneumogastric nerves, the trachea, and the oesophagus. Tributary to it are 
 both inferior thyroid veins. This vein meets the innominate of the right side to 
 form, with the vena azygos major, the descending vena cava. 
 
 VEINS OF THE UPPER EXTREMITIES. 
 
 These are both deep and superficial. The deep veins in the forearm are the 
 radial and ulnar, two for each artery, called radial and ulnar venae comites respec- 
 tively. They are connected by transverse branches, one to the other. The deep 
 veins of the forearm unite in the retiring angle of the elbow (cubital fossa) to 
 form the brachial vein or veins. 
 
 The Brachial Vein or Veins. This vein extends from the bend of the 
 elbow to the lower border of the latissimus dorsi tendon i. e., from the cubital 
 fossa to the base of the axillary space. Where there are two veins on each side 
 of the artery they communicate freely with each other and with the superficial 
 veins opposite to them in the superficial fascia. Sometimes the brachial receives 
 the basilic vein. 
 
 The axillary vein is the continuation of the brachial through the axillary 
 space. This vein has a valve in its lower one-third. It is in very close relation 
 with two axillary glands, on account of which this vein is of great surgical im- 
 portance in the operation for the removal of infiltrated axillary lymphatic glands. 
 This vein conveys nearly all the blood of the upper extremity. The axillary vein 
 is noted for the following large and important tributaries which it receives : 
 
 1. The circumflex (anterior and posterior). 
 
 2. The three subscapular veins. 
 
 3. The long thoracic vein. 
 
 4. Small and numerous alar thoracics from the axillary glands. 
 
 5. Short thoracic veins, the highest in the axillary space. 
 
 6. The long thoracic or external mammary vein. 
 
 7. The acromio-thoracic or thoracic axis vein of Morris. 
 
 The subclavian vein is the upward continuation of the axillary vein. It 
 unites with the internal jugular vein behind the sterno-clavicular articulation to 
 form the innominate or brachio-cephalic vein. On the outer surface of the first 
 rib it lies in a depression, and is separated from the subclavian artery by the 
 scalenus anticus muscle. In front of the vein are the clavicle and the subclavius 
 muscle. Tributaries are the cephalic and the external and anterior jugular veins. 
 On the left side, the thoracic duct opens into the beginning of the innominate, 
 between the subclavian and internal jugular ; on the right side the right lym- 
 phatic duct opens into a corresponding point of the right innominate vein. 
 
 The superior vena cava is formed by the confluence of the two innominate 
 veins. It begins near the junction of the sternum and first rib on the right side. 
 
476 PRACTICAL ANATOMY. 
 
 It is about three inches long. About one-half of the vessel is in the pericar- 
 dium. It returns practically all the blood to the heart from above the dia- 
 phragm. Its minor tributaries are the vena azygos major and minor and the 
 pericardiac, mediastinal, and oesophageal veins. The vena cava superior has no 
 valves, but its tributaries are provided therewith. The vessel opens into the right 
 auricle of the heart. 
 
 THE VEINS OF THE LOWER EXTREMITIES 
 
 Are but superficial and deep. The superficial veins are very numerous, anastomose 
 quite freely, but only two are of sufficient import to be entitled to special names. 
 The general name by which structures in the superficial fascia are designated is 
 cutaneous or superficial. The special names for the two important veins of the 
 lower extremity are : (i) Long saphenous ; (2) short saphenous. 
 
 The long saphenous vein begins at the inner end of the dorsal arch of the 
 foot, passes in front of the inner malleolus, behind the inner tuberosity of the 
 tibia and the inner condyle of the femur, and passes through the saphenous 
 opening in the fascia lata to become tributary to the common femoral vein. 
 Below the knee this vein is attended by the long saphenous nerve. This vein has 
 valves. It communicates with venae comites in its course. Above the knee its 
 tributaries are the superficial external pudic, the superficial epigastric, the super- 
 ficial circumflex iliac, and the internal and external femoral cutaneous veins. 
 
 The short saphenous vein begins at the outer end of the dorsal arch of 
 the foot, passes behind the outer malleolus, gains the mid-line of the leg pos- 
 teriorly, and pierces the popliteal fascia to become tributary to the popliteal vein. 
 The deep veins of the lower extremity accompany the arteries, and take 
 the same name, where there is but one vein to attend the artery; where, how- 
 ever, there are two, as is the case below the knee, then the term vence conritcs is 
 used. About one inch below Poupart's ligament the common femoral vein is 
 formed by the confluence of the superficial and deep femoral veins. The com- 
 mon femoral vein is in the femoral sheath, between the common femoral artery 
 and the femoral canal. Above Poupart's ligament this vessel is continued 
 upward, under the name of external iliac vein. Opposite the junction between the 
 sacrum and ilium the external iliac becomes confluent with the internal iliac vein, 
 to form the common iliac vein. 
 
 The ascending vena cava is formed by the confluence of the common iliac 
 veins. It begins opposite the fourth or fifth lumbar vertebra. It lies to the right 
 of the abdominal aorta. It passes through a groove on the posterior surface of 
 the liver. It passes through the caval opening in the diaphragm and opens into 
 the right auricle of the heart. The sacra media vein is the first tributary, the 
 hepatic vein the last tributary, that the vena cava receives in its course. Between 
 these two extremes the tributaries are numerous and important : the lumbar, 
 right spermatic or ovarian, renal, suprarenal, and phrenic. The left spermatic 
 \ein is tributary to the left renal, as is also its homologue, the ovarian. 
 
 The portal vein is formed by the gastric, splenic, superior mesenteric, and 
 inferior mesenteric arteries. These veins have no valves. Blood coming from 
 the abdominal organs is laden with bile and sugar, both of which are removed 
 In >m tin- portal blood by the liver. The bile is stored up in the gall-bladder ; 
 the sugar is stored up as potential energy in the hepatic cells. The portal vein 
 enters the root of tin- liver, between the hepatic artery and the common bile-duct. 
 
INDEX. 
 
 A. 
 
 Abdominal walls, 225 
 
 blood-supply, 233 
 contents, 246 
 
 review, 248 
 function of, 233 
 interior view, 235 
 nerve-supply, 233 
 Abscess, alveolar, 151 
 Accelerator of penis, 333 
 Adjectives, substantive, 21 
 Alcock's canal, 337 
 Anatomical root of the lung, 207 
 Anconeus, 355 
 
 Annular ligament, posterior, 348 
 Ansa hypoglossal nerve-loop, 155 
 Antagonism, anatomical, 18 
 
 law of, 308 
 
 Anterior thoracic nerves, 195 
 Antrum of Highmore, 116 
 
 analysis, 116 
 blood-supply, 117 
 Fillebrown on, 119 
 nerve-supply, 117 
 opening for, 118 
 Aponeurosis defined, 25 
 Apoplexy, nose-bleeding in, 114 
 Apposition, anatomical, 19 
 Arachnoid membrane, 123 
 
 appearance of, 126 
 Arch, fibrous, of gastrocnemius, 377 
 
 of soleus, 378 
 zygomatic, 28 
 
 Arches, fibrous, defined, 25 
 Arteries, gluteal, 372 
 
 laryngeal, superior and inferior, IIO 
 popliteal, 369 
 posterior tibial, 383 
 sciatic, 372 
 Artery, anterior tibial, 310 
 
 ascending pharyngeal, 63 
 brachial, and relations, 196 
 circumflex, internal, use of, 321 
 common carotid, 58 
 dorsalis pedis, 310 
 external carotid, 59 
 
 circumflex, 321 
 facial, 6 1 
 
 branches of, in neck, 6 1 
 femoral, 316 
 
 branches of, 320 
 inferior thyroid, 66 
 internal carotid, 59 
 
 mammary, 66 
 maxillary, 88 
 lingual, 60 
 occipital, 6l 
 posterior auricular, 63 
 princeps cervicis, 67 
 
 Artery, profunda femoris, 520 
 subclavian, 64 
 
 branches of, 65 
 superficial femoral, branches of, 321 
 
 temporal, 63 
 superior intercostal, 66 
 
 thyroid, 60 
 
 suprascapular, 66, 359 
 vertebral, and branches, 68 
 Articulations, 421 
 
 acromio-clavicular, 429 
 ankle, 445 
 
 atlanto-occipital, 467 
 carpal, 437 
 chondro-sternal, 473 
 coraco-clavicular, 430 
 costo-central, 471 
 costo-trans verse, 471 
 elbow, 432 
 
 femoro-acetabular, 439 
 knee, 440 
 medio-tarsal, 302 
 occipito-axoid, 468 
 pelvis, 453 
 radio-carpal, 435 
 *radio-ulnar, inferior, 434 
 radio-ulnar, superior, 432 
 sacro-coccygeal, 459 
 sacro-ischiatic, 457 
 sacro-vertebral, 460 
 shoulder, 426 
 sterno-clavicular, 431 
 table of, 422 
 tarsal, 446 
 
 temporo-mandibular, 425 
 tibio-fibular, 444 
 Arytenoid muscle, 109 
 Ascending vena cava, 212 
 Auriculo-temporal nerve, 37 
 
 ventricular valves, 218 
 Axilla, or axillary space, 188, 192 
 angles and contents of, 193 
 anterior boundary of, 192 
 
 thoracic nerves in, 195 
 apex of, bony boundaries of, 192 
 axillary artery and branches in, 196 
 base of, formation of, 192 
 circumflex nerve in, 195 
 contents of, 193 
 internal boundary of, 193 
 musculo-cutaneous nerve in, 195 
 musculo-spiral nerve in, 195 
 posterior boundary of, 192 
 subscapular nerves in, 195 
 systematic dissection of, 193 
 ulnar nerve in, 195 
 Axillary artery and vein, 196 
 
 space, 188, 192 
 Azygos uvulae, 98 
 
 477 
 
478 
 
 INDEX. 
 
 B. 
 
 Back, 374 
 
 accessorius, 405 
 arteries of, 398 
 cervicalis ascendens, 405 
 complexus muscle of, 394, 405 
 erector spinaa of, 394, 403 
 ilio-costalis, 405 
 latissimus clorsi, 399 
 levator anguli scapulae, 400 
 longissimus dorsi, 405 
 multifidus spinae, 407 
 nerves of, 397, 409 
 rhomboid muscles of, 400 
 rotatores spinae, 407 
 semispinales dorsi and colli, 396, 407 
 serratus posticus inferior, 400 
 superior, 400 
 
 seventh layer of muscles of, 407 
 simple movements of, 395 
 sixth layer of muscles of, 405 
 spinalis dorsi, 405 
 splenius capitis et colli, 400 
 suboccipital muscles, 409 
 triangle, 409 
 superficial fascia of, 394 
 table of muscles of, 395 
 trachelo-mastoid, 405 
 transversalis colli, 405 
 trapezius, 398 
 twelfth rib of, 394 
 vertebral aponeurosis of, 394, 400 
 Biceps, 185 
 Bile-duct, 251 
 Bladder, base of, 338 
 Blood-supply of the dura mater, 131 
 Bone : clavicle, inferior surface, 191 
 superior surface, 188 
 eminences and depressions of, 17 
 femur, anterior view, 327 
 
 posterior view, 326 . 
 hip-bone, internal surface, 287 
 
 posterior view, 325 
 humerus, anterior view, 184 
 mandible, inner view, 28 
 outer view, 28 
 maxilla, antrum, 118 
 
 inner view, 116 
 outer view, 1 17 
 metacarpal, fifth, base of, 152 
 pisiform, importance of, 152 
 ribs, first and second, 198 
 sacrum, anterior view, 290 
 scapula, dorsal surface, 345 
 skull, norma basilaris, 30 
 farialis, 29 
 lateralis, 27 
 sagittal section, 121 
 sternum, 199 
 
 styloid process of temporal, 87 
 tibia and fibula, anterior view, 300 
 posterior view, 301 
 lurbinated, 113 
 tympanum, 133 
 ulna and radius, anterior view, 179 
 
 posterior view, 353 
 unciform, importance of, 152 
 Brachial artery, 196 
 
 and branches, 196 
 pli'\us, 77 
 
 l!ra> lii.. i rph.ilir, 212 
 Jitat hi<> i.i'lialU, 185, 348 
 I'.iain, Mood supply of", 135 
 
 circle of Willis of, 135 
 
 Brain, coverings of, 120 
 
 ganglionic arteries of, 136 
 
 quiz on blood-supply of, 137 
 
 removal of, 125 
 
 structures seen on base of, 127 
 
 two systems of blood circulation of, 137 
 
 Branches of abdominal aorta, 258 
 
 Buccinator muscle, 93 
 
 C. 
 
 Calcaneum, posterior surface of, 299 
 superior surface of, 299 
 Calvarium, 121 
 
 removal of, 125 
 Capsules, 16 
 Cardiac plexus, 214 
 
 root, 2ii 
 
 Carotid artery, common, 58 
 external, 59 
 internal, 59 
 
 cavernous stage of, 131 
 
 petrosal stage of, 131 
 
 seen on removing the brain, 
 
 128 
 
 sheath, 58 
 Carpus and hand, exterior muscles of, 152 
 
 osteological points of, 152 
 Cavernous sinus, 129 
 Central perineal point, 338 
 Cephalic vein, 189 
 Cerebro-spinal fluid, 124 
 Cervical fascia, deep, 47 
 
 scheme of, 48 
 third layer, 57 
 plexus, 73 
 
 Chondro-sternal articulation, 473 
 Cinder in eye and pain, 150 
 Circulation, adult, 218 
 foetal, 219 
 Circumflex nerve, 195 
 
 quadrangular space, 355 
 Circumflexus palati, 98 
 Clavicle, 187 
 Clavi -pectoral fascia, 191 
 space, 191 
 
 Coccygeus muscle, 290 
 Compound words, 10 
 
 rule for, 10 
 
 Compressor narium, 34 
 Constrictor muscles of pharynx, 99 
 Cord, spermatic, 307 
 Coronary artery, 218 
 Corrugator cutis ani, 331 
 supercilii, 34 
 
 Crico-arytenoideus lateralis muscle, no 
 posticus muscle, no 
 Crico-thyroid muscle, no 
 Crura penis, 331 
 Crus penis, dissection of, 331 
 
 D. 
 
 Deep cervical fascia, second layer, 53 
 
 upper attachments and special 
 
 names for, 51 
 crural arch, 236 
 epigastric vessels, 236 
 Deltoid aponcurosi-. i 
 
 muscle, 189 
 
 Depressor agents of the lower jaw, 93 
 anguli oris, 32 
 laliii inferiori-i, 32 
 
INDEX. 
 
 479 
 
 Depressor muscles of hyoid bone, 55 
 
 Dermal muscles, aural, 41 
 
 grouped, 41 
 
 Descending vena cava, 212 
 
 Diaphragm, 285 
 
 Diaphragms sellse, 121 
 
 Digastric muscle, 63 
 
 Dilator naris, anterior, 34 
 posterior, 35 
 
 Dissecting defined, 19 
 
 Dr. Loring's case reported, 161 
 
 Duct, nasal, 140 
 
 Stenson's, 31 
 
 Ductus arteriosus, 211 
 
 Duodenum, dissection, 252 
 
 Dura mater, 121 
 
 arteries of, 123 
 nerves of, 123 
 sinuses of, 122 
 
 E. 
 
 Emissary structures, tabulated list of, 151 
 Eustachian tube, 102 
 
 muscles attached to, 103 
 External oblique muscle, 230 
 
 F. 
 
 Face, osteological points of, 29 
 Facial anastomotic blood areas, 42 
 artery, 38 
 nerve, 30 
 
 communication of, on the face, 37 
 dissection of, 36 
 divisions and branches, 37 
 escape of, 43 
 
 not the cause of toothache, 43 
 Falx cerebelli, 122 
 cerebri, 122 
 
 dissection of, 126 
 Fascia, 22 
 
 cribriform, 309 
 cubital, 24 
 deep, 23 
 
 associated with muscles, 24 
 attachments of, 308 
 forming intermuscular septa, 24 
 gives origin and insertion to muscles, 
 
 308 
 
 in surgical areas, 24 
 minor details of, 308 
 of thigh, 307 
 on back of carpus, 348 
 dorsal, 23 
 
 in foot, 24 
 iliac and pubic, 308 
 in the upper extremity, 23 
 lata, 23 
 
 subdivisions of, 308 
 of Colles, 338 
 of lower extremity, 23 
 palmar, 23 
 
 pelvic, special names for, 24 
 plantar, 24 
 popliteal, 24 
 special names for, 23 
 superficial, 23 
 
 characters of, 25 
 of lower extremity, 302 
 Female generative organs, 291 
 Femoral canal, 236 
 fossa, 236 
 
 Femoral hernia, 238 
 ring, 237 
 sheath, 236 
 Fibula, anterior surface of, 298 
 
 bony parts of, of interest, 298 
 external surface of, 298 
 internal surface of, 298 
 posterior surface of, 298 
 Fillebrown on opening for antrum, 119 
 Fissures of brain and their, contents, 139 
 Flexor longus pollicis, 184 
 
 profundus digitorum, 182 
 Foot and ankle, 298 
 
 bony parts of, of interest, 298 
 and leg, 297 
 dorsal arch of, 303 
 long saphenous vein of, 305 
 nerve of, external cutaneous, 307 
 long saphenous, 305 
 middle cutaneous, 306 
 musculo-cutaneous. 306 
 short saphenous, 306 
 short saphenous vein of, 305 
 Foramen, infra-orbital, 41 
 mentale, 41 
 of Winslow, 251 
 Foramina at base of skull, 128 
 
 nutrient, of bone, rule for, 171 
 of Key, Retzius, Magendie, 124 
 Forearm, arteries and veins of, 171 
 biceps of, 185 
 bones of, 1 68 
 brachialis anticus of, 185 
 cubital fossa of, 172 
 flexor longus pollicis of, 184 
 
 profundus digitorum of, 182 
 sublimis digitorum of, 179 
 flexors of, 185 
 median nerve of, 181 
 muscles of, physiologically grouped, 171 
 nerves of, grouped, 171 
 pronator quadratus of, 184 
 radial artery of, 179 
 groove of, 172 
 supinator longus, 185 
 surgical areas of, 171 
 ulnar artery of, 177 
 groove of, 173 
 nerve of, 182 
 Frown, complete, 42 
 
 G. 
 
 Ganglion, otic, 91 
 
 subtnaxillary, 90 
 Gasserian ganglion, 129 
 
 description of, 131 
 Genio-hyo-glossus muscle, 8l 
 Geometrical terms and figures, 2O 
 Gland, lachrymal, 139 
 
 location of, 147 
 thyroid, 57 
 
 Glands, Pacchionian, 125 
 Grooves for flexor longus hallucis, 299 
 
 H. 
 
 Hallucis, extensor proprius, 312 
 Hand, anterior annular ligament, 162 
 
 attachment of, 167 
 perforating arteries in, 166 
 articular nerves of, and rule, 167 
 blood-supply of, 1 68 
 bones of, 152 
 
480 
 
 INDEX. 
 
 Hand, carpal arteries in, 166 
 
 cutaneous nerves of, 155 
 deep fascia of, 157 
 
 palmar arch of, 1 68 
 
 branch of ulnar nerves in, 165 
 dissection of, 158 
 flexor tendons of, 159 
 hypothenar group of muscles of, 164 
 infection of fingers of, 167 
 median nerve in, and dissection of, 162 
 palmar fascia of, 159 
 
 interossei muscles of, 165 
 radial artery in, 166 
 sensory nerves of, 167 
 superficial arch of, 168 
 surgical areas in fingers of, 167 
 thecne of, 160 
 thecal culs-de-sac of, 160 
 tlienar group of muscles of, 162 
 ulnar artery in, 166 
 
 nerve in, and dissection of, 162 
 Hepatic artery, 251 
 Hesselbach's triangle, 233 
 Highmore, antrum of, 116 
 
 analysis of, 116 
 blood-supply, 117 
 drainage of, 117 
 nerve-supply, 117 
 opening for, 118 
 Hilton's law, 19 
 
 Humerus, bicipital groove and lip of, 171 
 external condylar ridge of, 171 
 fracture in middle third of, 171 
 muscles and ligaments attached to, 171 
 nutrient foramen of, 171 
 osteology of, 170 
 outer and inner surfaces of, 171 
 posterior surface of, 171 
 relation of, to musculo-spiral nerve, 171 
 Hunter's canal, 323 
 Hyo-glossus muscle, 64 
 Hyoid bone, movements of, 80 
 Hypogastric plexus, 273 
 Hypoglossal nerve, 63 
 
 I. 
 
 Iliac artery, internal, 278 
 
 fascia, 275 
 
 Iliacus muscle, 279, 289 
 Ilio-hypogastric nerve, 235 
 Ilio-inguinal nerve, 235 
 Inferior mesenteric artery, 257 
 Inguinal canal, analysis, 230 
 fossa, 236 
 hernia, 234 
 Innominate veins, 475 
 Intercostal fascia, 201 
 muscles, 201 
 nerves, 201 
 
 Interior of thorax, 204 
 Int. TIKI] abdominal ring, 236 
 cutaneous nerve, 195 
 mammary artery, 204 
 ol'!i(|ue muscle, 231 
 Intestin.-, | : ,rg.- and small, 248 
 Ischio-rectal fossa, 279 
 
 J- 
 
 Jugular vein, internal, vS 
 
 superficial, 46 
 
 Ju\t;i. 1 ; 
 
 K. 
 
 Kidney, descriptive terms of, 260 
 left, relations of, 259 
 right, relations of, 258 
 root-structures of, 259 
 ureter of, 292 
 
 Knee-joint, 440 
 
 ligaments of, 442 
 
 L. 
 
 Larynx, 106 
 
 arytenoid cartilage of, 108 
 
 muscle of, 109 
 blood-supply of, 1 10 
 
 crico-arytenoideus lateralis muscle of, no 
 posticus muscle of, no 
 cricoid cartilage of, 108 
 crico-thyroid muscle of, 1 10 
 false vocal cords of, 109 
 inferior laryngeal nerve of, 109 
 retiring angle of, 108 
 superior laryngeal nerve of, 109 
 thyro-arytenoid muscle of, 109 
 thyroid cartilage of, 107 
 true vocal cords of, 109 
 Latissimus dorsi, 196 
 Law of projectiles, 21 
 Levator anguli oris, 32 
 
 scapulae, 69 
 ani, 291 
 labii superioris, 32 
 
 akeque nasi, 33 
 menti, 34 
 palati muscle, 98 
 
 Ligament, anterior annular, at the wrist and struc- 
 tures under, 162 
 (foot), 23 
 relations, 162 
 external annular, 24 
 interior annular (hand), 23 
 internal annular, 24 
 posterior annular, 23 
 Ligamenta vaginales of foot, 24 
 
 of hand, 159 
 
 Ligamentum vaginale, 23 
 Liver, 253 
 
 arteries and nerves of, 255 
 foetal remains of, 255 
 how described, 256 
 ligaments of, 253 
 root-structures of, 251 
 Longus colli muscle, 104 
 Lumbar plexus, 275 
 Lymphatics of neck, superficial, 46 
 
 M. 
 Mandible, 29 
 
 Irv.ilors ;m<l depressors of, 93 
 muscles concerned in dislocation of, 96 
 Masseter muscle, 49 
 
 superficial and deep parts of, 93 
 Meckel's fascia, space, cave, 151 
 Median nerve, 182 
 Mediastinal spaces, 208 
 Membranes, mucous, character of, 26 
 serous, diameter of, 25 
 Mimual, character of, 26 
 Meningral artc-iy, middle, 130 
 Mrnin^c.-,. 121 
 
 Mouth, study nf, on cadaver, 79 
 on living, 711 
 
INDEX. 
 
 481 
 
 Muscles, abductor, of thigh, 377 
 accelerator urinse, 333 
 adductor longus, 315 
 
 of thigh, 377 
 anconeus, 355 
 aponeurosis of, 25 
 arising from styloid process, 85 
 biceps, 185 
 brachialis anticus, 185 
 brachio-radialis, 185, 348 
 compressor narium, 34 
 corrugator supercilii, 34 
 deltoid, 189, 335 
 depressor anguli oris, 32 
 
 labii inferioris, 32 
 depressors of the hyoid bone, 56 
 digastric, 63 
 dilator naris, anterior, 34 
 
 posterior, 35 
 dorsal interossei, 354 
 erector penis, 333 
 extensor brevis digitorum, 310 
 
 pollicis, 351 
 
 carpi radialis brevior, 349 
 longior, 349 
 ulnaris, 350 
 
 communis digitorum, 350 
 indicis, 351 
 longus digitorum, 312 
 
 pollicis, 351 
 minimi digiti, 350 
 of thigh, 377 
 
 ossis metacarpi pollicis, 351 
 proprius hallucis, 312 
 external oblique, 229 
 pterygoid, 83 
 fanciful names for, 19 
 fibrous arches of, 25 
 flexor carpi radialis, 176 
 
 longus digitorum, 384 
 
 hallucis, grooves for, 384 
 of thigh, 377 
 profundus digitorum, 182 
 sublimis digitorum, 179 
 forming musculatures, 25 
 genio-hyo-glossus, 8 1 
 gluteus maximus, 370 
 medius, 371 
 minimus, 371 
 gracilis, 315 
 hyo-glossus, 64 
 hypothenar group of, 164 
 iliacus, 279, 289 
 infraspinatus, 358 
 in movements of hip, 377 
 in region of shoulder, 355 
 intercostal, 200 
 
 external, 200 
 internal, 201 
 internal oblique, 231 
 pterygoid, 83 
 interossei, dorsal, 362 
 involuntary, 14 
 latissimus dorsi, 196, 356 
 levator anguli oris, 32 
 
 scapulae, 69 
 ani, 291, 332 
 labii superioris, 32 
 
 alseque nasi, 33 
 menti, 34 
 longus colli, 105 
 masseter, 49 
 mylo-hyoid, 81 
 
 relations of, 82 
 
 Muscles, obturator externus, 289 
 
 internus, 289, 279 
 
 dissection of, 375 
 occipito-frontalis, 120 
 of anterior surface of fibula, 310 
 of facial expression, 35 
 of forearm, anterior and radial, physio- 
 logically grouped, 171 
 of leg, deep, 384 
 of mastication, 93 
 
 nerve-supply, 96 
 of the eyeball, 145 
 of the larynx, 109, no 
 of the orbit and their function, 149 
 of the pharynx, 99 
 of the soft palate, 98 
 orbicular and sphincter, 19 
 orbicularis oris, 33 
 
 palpebrarum, 33 
 origin and insertion of, 25 
 palato-glossus, action of, 85 
 palato-pharyngeus, 86 
 
 paralysis of, 86 
 palmar interossei, 165 
 palmaris brevis, 161 
 longus, 176 
 pectoralis major, 189 
 minor, 191 
 peronei, 384 
 peroneus tertius, 315 
 physiological adductor, 328 
 plantaris, 377 
 platysma myoides, 45 
 pronator quadratus, 184 
 radii teres, 177 
 psoas magnus, 288 
 
 relations, 275 
 parvus, 289 
 pyramidalis, 232 
 
 nasi, 34 
 
 pyriformis, 289, 372 
 quadratus lumborum, 287 
 radial group of, 349 
 rationale of naming, n 
 rectus abdominis, 232 
 
 capitis anticus major, 103 
 minor, 104 
 femoris, 317, 325 
 rotator, external, 377 
 internal, 377 
 sartorius, 315 
 scaleni, 68, 200 , 
 
 origin of, 69 
 semimembranosus, 369 
 serratus magnus, 196 
 shape of, 1 8 
 
 index to nerve-supply, 18 
 sphincter and orbicular, 19 
 
 distinguished, 2O 
 sterno-mastoid, 50 
 
 relations, 52 
 stylo-glossus, 82 
 stylo-hyoid, 82 
 subclavius, 191, 200 
 subscapularis, 196 
 substantive adjectives of, 21 
 supinator longus, 349 
 
 radii brevis, 354 
 longus, 348 
 supraspinatus, 358 
 synonymous usage of, 19 
 temporal, 50 
 teres major, 196, 356 
 minor, 356 
 
482 
 
 Muscles, thenar group of, 162 
 
 tibialis anticus, 310 
 
 transversalis, 232 
 
 colli, 68 
 
 transversus perinsei, 334 
 
 triangularis sterni, 204 
 
 triceps, 359 
 
 under anterior annular ligament, 102 
 posterior annular ligament, 348 
 
 vasti, internus, externus, 318, 325 
 
 zygomatici, major and minor, 33 
 Musculature defined, 25 
 Mtisculi lingualis, 82 
 
 lumbricales, 162 
 
 N. 
 Nasal fossae, 1 1 1 
 
 arteries of, 114 
 geometry of, ill 
 hemorrhage of, 114 
 meatuses of, 113, 116 
 mucous membrane of, 113 
 nerve-supply of, 115 
 turbinated bones of, 113 
 Neck, boundaries of, 44 
 dissection of, 43 
 jugular veins of, 46 
 lymphatic T of, 46 
 quiz on, 48, 49, 55, 56, 57 
 surgical and medical areas of, 44 
 triangles of, 44 
 Nerve, abducens, description of, 149 
 
 anterior thoracic, in the axilla, 195 
 
 tibial, 310 
 auditory, 416 
 chorda tympani, 90 
 circumflex, 361, 363 
 
 in the axilla, 195 
 cranial, classification, 410 
 origin of, 410 
 summary, 410 
 
 cutaneous branches of external plantar, 387 
 of internal plantar, 387 
 of lower extremity, 365 
 of upper extremity, 155 
 eighth cranial auditory, 128 
 eleventh cranial, 128 
 endings, 26 
 external popliteal, 367 
 facial, 415 
 
 dissection of, in the petrosa, 135 
 fifth cranial, trigeminus, 128 
 fourth cranial, patheticus, 128 
 frontal, description of, 148 
 glosso-pharyngeal, 92, 416 
 gluteal, superior, 372 
 great sciatic, 372 
 hypoglossal, 63, 426 
 ilio-hypogastric, 365 
 inferior gluteal, 373 
 infi:i-orbital, 31, 1 10 
 internal cutaneous, in the axilla, 195 
 
 pudic, 374 
 
 lachrymal, description of, 148 
 l;u yngeal, superior and inferior, 109 
 lesser internal cutaneous, in tin- axilla, 195 
 long saphenous, 366 
 median, 362 
 
 symptoms in paralysis of, 167 
 ment 
 niotm .MII 
 
 description of, 148 
 musculo-cutaii' : ^63 
 
 INDEX. 
 
 Nerve, musculo-cutaneous, in the axilla, 195 
 musculo-spiral, 195, 361, 363 
 
 in the axilla, 195 
 mylo-hyoid, 87 
 nasal, 145 
 
 description of, 148 
 distribution of, 118 
 ninth cranial, 128 
 olfactory, 411 
 
 distribution of, 118 
 optic, 412 
 
 description of, 149 
 patheticus, 413 
 
 description of, 148 
 phrenic, 69 
 
 plantar, cutaneous, 387 
 external, 392 
 internal, 392 
 
 pneumogastric, branches of, in the neck, 58 
 popliteal, internal, 378 
 posterior interosseous, 362 
 
 tibial, 379, 382 
 seventh cranial, facial, 128 
 short saphenous, 369 
 sixth cranial, 128 
 small sciatic, 366, 372 
 spinal accessory, 45, 417 
 
 ganglia of, 410 
 
 subscapular, in the axilla, 195 
 supraorbital, 31 
 suprascapular, 361 
 tenth cranial, 128 
 tibial, posterior, 379 
 trifacial, 413 
 twelfth cranial, 128 
 
 thoracic, 365 
 ulnar, 362 
 
 in the axilla, 195 
 symptoms in paralysis of, 167 
 vagus, 411, 417 
 
 root-ganglion, 411 
 trunk-ganglion, 411 
 
 Noise, cracking, in temporo-mandibular joint, 96 
 Nomenclature, 9 
 
 grammatical note on, 12 
 
 O. 
 
 Obturator externus muscle, 289 
 fascia, 275 
 
 internus muscle, 279, 289 
 Occipito-frontalis muscle, 120 
 Ocular muscles, table of origin of, 145 
 OZsophagus, 216 
 Opposites, anatomical, 10 
 Orbicularis oris, 33 
 
 antagonists of, 1 1 
 palpebrarum, 33 
 Orbit, angles of, 140 
 contents of, 141 
 dissection of, 141 
 geometry of, 139 
 lachrymal gland of, 139 
 muscles of, and their function, 149 
 nasal duct of, 140 
 nerves of strut -lures seen in, 149 
 ophthalmic artery of, 145 
 
 vein of, and its physiological an< 
 pathological importance, 150 
 periosteum of, 141 
 trochlea of, 140 
 Ovarian artery, 294 
 
INDEX. 
 
 483 
 
 P. 
 
 Pacchionian bodies and vHli, 126 
 
 glands, 125 
 
 Pain, classification of, 266 
 reflex motor, 268 
 
 rationale, 268 
 sensory, 268 
 somatic, 266 
 sympathetic, 266 
 
 table of common diseases showing, 266 
 transmission of, 266 
 Palate, soft, analysis of, 98 
 
 how formed, 85 
 
 Palato-glossus muscle, action, 85 
 Palato-pharyngeus muscle, 86 
 
 paralysis of, 86 
 Pancreas, 252 
 Paralysis of median nerve, symptoms, 168 
 
 of ulnar nerve, symptoms, 167 
 Parotid fascia, 40 
 
 gland, contents of, 40 
 
 excretory duct, 40 
 explanation of, 43 
 limitations of, 40 
 Patella, 298 
 
 reflex, 284 
 
 rationale of, 285 
 Patient's eye, 150 
 Pectoralis major muscle, 189 
 minor muscle, 191 
 Pelvic fascia, 275,338 
 outlet, 330 
 
 anterior triangle of, 330 
 
 dissection of, 333 
 
 external sphincter ani muscle of, 332 
 
 female, 340, 341 
 
 greater sacro-sciatic ligament of, 332 
 
 hsemorrhoidal arteries of, 332 
 
 ischio-rectal fossa in, 336 
 
 levator ani muscle of, 332 
 
 posterior triangle of, 330 
 
 superficial fascia (Colics') of, 331 
 
 transversus perinaei muscle 
 
 of, 33 2 
 
 tendinous centres of, 332 
 triangular ligaments of, 336 
 white line, 291 
 Pelvis, deep dissection of, 286 
 
 dissection of, 274 
 Penis, accelerator of, 333 
 
 blood-supply of, 339 
 bulb of, 331 
 crura, 331 
 
 cms, dissection of, 333 
 dissection of, 334 
 nerve-supply of, 340 
 Peri-, 13 
 Pericardium, 210 
 Periosteum and its functions, 17 
 Peritoneum, 238 
 
 blood-supply of, 239 
 cavities of, 252 
 investing organs, 240 
 review of, 239 
 Peroneus brevis, 299 
 longus, 299 
 
 Phalanges, palmar surface of, 153 
 Pharynx, 99 
 
 attachments of, 103 
 nerve-supply of, 103 
 Phlebotomy, 166 
 Pia mater, composition of, 127 
 Pituitary membrane, 113 
 
 Platysma myoides, 45 
 Plexus, brachial, 77 
 
 cervical, ascending branches, 45 
 descending branches, 46 
 explanation of, 73 
 superficial branches, 45 
 infra-orbital, 42 
 vesico-prostatic, 339 
 Plica hypogastrica, 236 
 
 urachi, 236 
 
 Pneumogastric nerve, 217 
 Popliteal nerve, external, 284 
 internal, 283 
 Portal vein, 252 
 Posterior mediastinum, 215 
 Poupart's ligament, 323 
 Pre-, 13 
 
 Prepositions, technical use of, 12 
 Projectiles, application of law of, 22 
 
 law of, 21 
 
 Pronator quadratus muscle, 184 
 Prostate gland, 339 
 Psoas magnus, 288 
 
 relations of, 275 
 parvus, 289 
 
 Pterygoid muscle, external, 87, 95 
 internal, 87, 93 
 plexus, 151, 474 
 Pudic nerve, internal, 282 
 Pulmonary artery, 211 
 
 trio, 207 
 
 Pus from carious tooth, 151 
 Pyramidalis nasi, 34 
 Pyriformis muscle, 289 
 
 R. 
 
 Radial nerve, 355 
 
 oblique line, 185 
 Radius, osteology of, 1 68 
 Rectum, 275 
 
 Rectus capitis anticus major muscle, 103 
 minor muscle, 104 
 
 muscle, 232 
 
 Reflex pain, primary and secondary, 92 
 Region of shoulder, 355 
 Rib, typical, 201 
 Roots, anatomical, 17 
 Root-structures of liver, 251 
 
 S. 
 
 Sacral plexus, 280 
 
 branches of, 281 
 Salivary system, 98 
 Salpingo-pharyngeus muscle, 103 
 Saphenous opening, 309 
 Scaleni muscles, 68, 201 
 
 scheme of origin of, 69 
 Scapula, 186 
 
 anterior lip of vertebral border of, 187 
 fracture of surgical neck of, 187 
 middle lip of axillary border of, 187 
 
 vertebral border of, 187 
 osteology of, 186 
 Scapular fossae, three, 186 
 
 spine, lips of, 187 
 Scarpa's triangle, 322 
 Scheme for deep cervical fascia, 190 
 Sciatic nerve, greater, 283 
 
 lesser, 283 
 Semilunar fold of Douglas, 225 
 
 valves, 218 
 Seminal vesicles, 338 
 
4 8 4 
 
 INDEX. 
 
 Serratus magnus muscle, 196 
 Sheaths, anatomical, 16 
 carotid, 58 
 of rectus muscle, 225 
 rationale of formation of, 1 6 
 Shoulder, 186 
 
 cephalic vein of, 189 
 clavi-pectoral fascia of, 191 
 costo-coracoid ligament of, 191 
 deltoid aponeurosis of, 189 
 
 muscle of, 189 
 
 pectoralis major muscle of, 189 
 minor muscle of, 191 
 subclavius muscle of, 187 
 Sinus, cavernous, and contents, 129 
 
 superior longitudinal, 126 
 Skull, base of, 31 
 
 fissures of, 31 
 
 Sole of foot, arterial arch of, 392 
 deep fascia of, 388 
 external plantar artery of, 392 
 internal plantar artery of, 392 
 granular fat of, 390 
 ligamenta vaginales of, 391 
 lumbricals of, 393 
 muscles of, 386, 390 
 
 of first layer of, 392 
 plantar fascia of, 390 
 theca and thecal culs-de-sac of, 391 
 Some interesting facts about veins, 473 
 Spermatic cord, 307 
 
 Spinal accessory nerve, how distinguished in surgi- 
 cal operations, 45 
 Splanchnic nerves, 216 
 Splenic artery, 252 
 Stenson's duct, course of, 45 
 Sterno-cleido-mastoid muscle, 50 
 
 nerve-supply, 51 
 relations of, 52 
 sheath, 50 
 Sternum and ribs, inner, 202 
 
 ribs, and articulation, 198 
 Stomach, 253 
 Stylo-glossus muscle, 82 
 Stylo-hyoid muscle, 82 
 Styloid process, 87 
 Sub-, 12 
 
 Subarachnoid fluid, 123 
 space, 123 
 
 special features of, 124 
 Subclavian artery, branches of, 65 
 Subclavius muscle, 200 
 
 and sheath, 19! 
 
 Subdural space, contents of, 126 
 Subscapular nerves, 195 
 Summary of peritoneal considerations, 246 
 Superior mesenteric artery, 256 
 
 vena cava, 475 
 Supinator longus, 348 
 Supra-, 13 
 
 Supraorbital foramen, 139 
 Suprascapular artery and nerve, 359 
 Supraspinatus, 358 
 Surgical areas : 
 
 Alcock's canal, 337 
 Anastoni' : face, 42 
 
 Antnun (it I lighmore, the, Il6 
 Auditory canal, 92 
 Axillary artery, the, 196 
 
 <-. the, 188, 192 
 Pile ducts, the, 251 
 Piaeliial uti-iv, tin-, 196 
 
 nil ami appendix, the, 248 
 < 'alvarium. llir. 121 
 i. 
 
 Surgical areas : 
 
 Colics' fascia, 331 
 Cribriform fascia, the, 309 
 Cubital fossa, the, 172, 174 
 Deep palmar arch, 168 
 Dislocation of jaw, 96 
 Emissary foramina and their veins, 150 
 Eustachian tube, 102 
 Face, the, 151 
 Facial nerve, the, 135 
 Fascia, deep, of upper extremity, 363 
 Female pelvic outlet, the, 340 
 Femoral fossa, the, 236 
 ring, the, 237 
 sheath, the, 236 
 Fingers, 167 
 Foramen of Winslow, the, 251 
 
 sacro-sciatic. greater, 372 
 
 lesser, 373 
 
 Fossa, cubital contents, 364 
 Gasserian ganglion, the, 129 
 Geometrically considered, 20 
 Glandulae concatenatae, 58 
 Groove for flexor longus hallucis, 384 
 for posterior tibial artery, 383 
 radial, contents, 363 
 ulnar contents, 363 
 Hesselbach's triangle, 233 
 Hunter's canal, 323 
 Hymen, the, 341 
 Inguinal canal, the, 230 
 Intramural sinuses, the, 115 
 Ischio-rectal fossa, 279, 336 
 Kidneys, posterior relations, 259 
 
 right, anterior relations, 258 
 root-structures, 259 
 Larynx, the, 1 06 
 Ligaments, internal annular, 384 
 Liver, the, 253 
 
 Long saphenous vein, the, 305 
 Male urethra, the, 339 
 Median basilic vein in venesection, 167 
 Middle meningeal artery, the, 130 
 Nasal duct, the, 140 
 
 fossae, the, III 
 Neck, boundaries of, the, 44 
 
 surgical areas of, the, 44 
 
 triangles of, the, 44 
 Orbit, the, 139 
 Paralysis of median nerve, 168 
 
 ulnar nerve, 167 
 
 Parotid gland, location by limitation, 40 
 Pelvic outlet, the, 337 
 Perineal body, the, 343 
 Peritoneal cavities, the, 252 
 Peritoneum, the, 238 
 Popliteal space, 366 
 Posterior tibial canal, 383 
 Poupart's ligament, 323 
 Prostate, the, 339 
 Quadrangular space, the, 356 
 Radial groove, the, 172 
 Reflex pain, primary and secondary, 92 
 Root-structures of liver, 251 
 Saphenous opening, the, 309 
 Scarpa's triangle, 322 
 Septic thrombi in alveolar abscess, 151 
 
 in erysipelas of the face, 
 Soft palate, the, 99 
 Spermatic cord, the, 231 
 Stomach, the, 253 
 Superlicial palmar aivh. i"S 
 Table of pain in o.mimm diseases, 266 
 Thecal culs-de-sac, the, 161 
 Trachea, the, no 
 
INDEX. 
 
 485 
 
 Surgical areas : 
 
 Triangular space, the, 355 
 Tympanum, the, 131 
 Ulnar groove, the, 173 
 Sustentaculum tali, 299 
 Sympathetic nerve, 261 
 
 essentials of, 271 
 in abdomen, 270 
 
 T. 
 
 Table of origin of ocular muscles, 145 
 Tarso-metatarsal joint, 302 
 Temporal muscle, 5> 93 
 
 ridge, complete, 27 
 Temporo-mandibular articulation, 97 
 Tendo oculi, 140 
 Tentorium cerebelli, 122 
 Teres major, 196 
 
 and latissimus dorsi, 356 
 minor, 356 
 
 Thigh, fascial septa of, 328 
 Thoracic aorta, 213 
 
 duct, 213, 216 
 gangliated cord, 216 
 viscera, posterior view, 214 
 Thorax, 198 
 
 anatomical root of lung, 207 
 ascending vena cava, 212 
 brachio-cephalic veins, 212 
 cardiac and pulmonary plexuses, 214 
 
 root-structures, 211 
 clavi-pectoral fascia of, 200 
 contents of anterior mediastinum, 208 
 of middle mediastinum, 209 
 of posterior mediastinum, 209 
 descending vena cava, 212 
 ductus arteriosus, 211 
 geometry of, 204 
 hydro-thorax, pneumo-thorax, pyo-thqrax, 
 
 pyo-pneumo-thorax, 206 
 inner surface of sternum and ribs, 202 
 intercostal muscles and fasciae of, 200 
 
 nerve, typical, 2OI 
 internal mammary artery, 204 
 mediastinal spaces of, 208 
 posterior view of viscera, 214 
 pulmonary artery, 211 
 scaleni muscles, 200 
 subclavius muscle, 200 
 subdivisions of, 205 
 Thrombi, septic, 151 
 Thymus gland, 211 
 Thyro-arytenoid muscle, 109 
 Thyroid gland, 157 
 Tibia and semi-membranosus, 297 
 articular surfaces of, 297 
 bony parts of interest of, 297 
 internal malleolus of, 298 
 
 surface of, 297 
 oblique line of, 298 
 posterior surface of, 297 
 vertical line of, 298 
 Tibialis anticus, insertions of, 299 
 posticus, insertions of, 299 
 
 small insertion of, 299 
 Tissues, anatomical, 13 
 connective, 14 
 
 forms of, 14 
 constituents of, 15 
 muscular, 13 
 Tissues, nerve, 14 
 
 resume of, 16 
 
 Tongue, dissection of, 79 
 
 movements of, 8 1 
 Tonsil, 87 
 
 Toothache in the ear, 92 
 Trachea, no 
 
 blood -supply, ill 
 nerve-supply, in 
 relations of, III 
 structure of, I IO 
 Transversalis muscle, 232 
 Triangular space, 355 
 Trituration, muscles of, 93 
 Tubercles, supra- and infra -glenoid, 186 
 Tympanum, or middle ear, 131 
 dissection of, 135 
 facial nerve in relation to, 133 
 geometric analysis of, 132 
 importance of, 132 
 Typical rib, osteology of, 201 
 
 U. 
 
 Ulna, anterior surface of, 169 
 internal surface of, 169 
 osteology of, 169 
 posterior surface of, 169 
 vertical line of, 170 
 Ulnar nerve, 182, 195 
 
 paralysis of, 167 
 Urethra, 334 
 
 V. 
 
 Veins, angular and ophthalmic, 39 
 axillary, 475 
 brachial, 475 
 
 cephalic, at the shoulder, 166 
 in venesection, 166 
 cerebral, 126 
 
 classification of, 138 
 common temporal, 474 
 communication between the superficial veins 
 
 and the deep veins, 166 
 external jugular, 474 
 facial, 6l, 474 
 innominate, 475 
 internal maxillary, 474 
 jugular, internal, 58, 474 
 long saphenous, 476 
 median, 156 
 occipital, 474 
 of the face, 39 
 of the lower extremity, 476 
 
 deep, 476 
 
 of the upper extremity, 475 
 portal, 476 
 radial, 155 
 
 some interesting facts about, 473 
 subclavian, 64, 475 
 superficial, of forearm, 155 
 termination of ulnar, median, radial, 166 
 ulnar, 156 
 Vena azygos major, 216 
 
 cava, ascending, 212, 476 
 descending, 212 
 superior, 475 
 Venae comites, 166 
 Venesection, criminal liability in, 167 
 Vesiculse seminales, 339 
 Vestibule of oral cavity, 85 
 Vincula, 161 
 
 Viscera, posterior view of, 214 
 Vocal cords, true and false, 109 
 
 W. 
 
 Winslow, foramen of, 251 
 

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 AUG ^ i 1344 
 
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