OF CENTER LIBRARY SAN FRANCISCO SURGICAL ANATOMY DEAVER GENERAL ARRANGEMENT OF CONTENTS VOLUME I. UPPER. EXTREMITY BACK OK NKCK SHOULDER THINK CRANIUM SCALP FACE. VOLUME II. NECK MOUTH PHARYNX LARYNX NOSE OHBIT EYEBAI.I.- ORGAN OK HEARING BRAIN FK.MAI.E PERINEUM MALE PKKINEUM. VOLUME III. ABDOMINAL WALL ABDOMINAL CAVITY PELVIC CAVITY - CHEST LOWER EXTREMITY. SURGICAL ANATOMY A TPxEATISE ON HUMAN ANATOMY IN ITS APPLICATION TO THE PRAC- TICE OF MEDICINE AND SURGERY BY JOHN B. DEAVER, M.P SURGEOX-IN-CHIKF TO THK <;ERMAX HOSPITAL, PHILADELPHIA IX THREE VOLUMES ILLVXrilATKD II Y AKOUT 400 PLATES SEA11L Y ALL ]>KA\\'NFOB 77//.V WORK FHHM ORKHXAL DIXXM'TIOXS VOL. I. UPPER EXTREMITY; BACK OF NECK; SHOULDER; TRUNK; CRANIUM; SCALP; FACE PHILADELPHIA P. BLAKISTON'S SON & CO. 1012 WALNUT STREET 1899 PRESS OF WH. F. FELL & Co., 1220-24 SANSOM ST., PHILADELPHIA. . ls',19, BV P. BLAKISTOX'S SON >^ Co. TO Surgeons ano to Stuoents of Surgerg ano Hnatomy, WHOSE LABORS IT IS INTENDED TO LIGHTEN IN A FIELD WHERE LABOR ALONE IS THE PRICE OF ATTAINMENT, THIS WORK IS RESPECTFULLY DEDICATED BY THEIR FRIEND AND FELLOW-STUDENT THE AUTHOR. CONTENTS OF VOLUME I. PAGE UPPER EXTREMITY, 17 SURFACE ANATOMY or THE UPPER EXTREMITY, 17 THE FOREARM AND WRIST, 31 THE HAND, 32 NuiiVE STRETCHING AMI XERVE SECTION, 38 DISSECTION, 47 THE FRONT OF THE ARM, 96 THE FRONT OF THE FOREARM, 125 THE FRONT OF THE HAND, 152 THE BACK OF THE ARM, 188 THE BACK OF THE FOREARM, 195 THE BACK OF THE HAND, 209 JOINTS, 212 The Sterno-davicolar Joint, 215 The Scapulo-clavicular Joint, 221 The Shoulder-joint, 222 The Elbow-joint, 224 Radio-ulnar Articulations, 233 The Radio-carpal Articulation, 234 The Carpal Joints 238 Carpo-metacarpal Articulations, 242 The Intermetacarpal Articulations, 245 The Interphalangeal Articulations, 247 DISLOCATIONS, 247 ANATOMY OF THE LONG BONES, 256 EXCISIONS, 260 DEVELOPMENT OF THE BONES, 266 FRACTURES 269 AMPUTATIONS, 279 LlGATIONS OF THE ARTERIES, 294 STRETCHING OF THE NERVES 311 THE BACK OF THE NECK, SHOULDER, AND TRUNK, 351 LIGAMENTS OF THE VERTEBRAL COLUMN 412 vii viii CO.V7Vv.V7X or VOU'UE I. PAOl FRACTURES AND DISLOCATIONS OF THE YKKTKHHA, 4-24 DISSECTION, 4:24 THE SPINAL CURD, 4 IN SURFACE ANATO.MV OF THE CRANIUM 451 SURFACE ANATOMY OF THE FACE 156 SCALP 4ii:. FACE, 189 PTERYGO-.MAXILI.AKY REUIOX, 540 THE MEMBRANKS AND VKSSKI.S OF THE BRAIN, '.r,s INTRA-CHAMAL COI-RXE AM. MOLE OF EXIT OF THE CRANIAL NERVES, 5'.H INDEX. 001 LIST OF ILLUSTRATIONS. PLATE I'M.I I. Forearm Pronated, 20 II. Forearm Supinated, Showing Ulnar Deflection, 21 III. Landmarks of Anterior Surface 24 IV. Landmarks of Posterior Surface, 25 V. Dislocated Shoulder and Normal Shoulder, L". VI. Principal Flexor Furrows, :;l VII. Lines of Arteries Palm of Hand, :;."> VIII. Anterior View of Upper Extremity Motor Points, 40 IX. Motor Points and Lines of Incisions for Posterior Circumflex Artery and Musculo- spiral Nerve 41 X. Dorsum of Scapula Showing Acromial Angle, . . 43 XI. Lines of Incisions for Dissection and J /me for Axillary Artery, 45 XII. Superficial Fascia of Pectoral Region, 49 XIII. Anterior Cutaneous and Lateral Cutaneous Nerves 52 XIV. Mammary Gland, 55 XV. Deep Fascia or Pectoral Fascia and Axillary Fascia, 5'.i XVI. Diagram of Pectoral Fascia and Axillary Fascia. / . . . . 02 XVII. Pectoralis Major Muscle and PectoraEs Minor Muscle, ii5 XVIII. Superficial Infra-clavicular Triangle, 70 XIX. Deep Infra-clavicular Triangle, 71 XX. Contents of Axilla Shown by Dissection Made from Before Backward, 7(> XXI. Contents of Axilla Shown by Dissection Made from Below Upward, 77 XXII. Anastomoses of Arteries Around the Scapula, s4 XXIII. Axillary or Brachial Plexus of Nerves, S7 XXIV. Incisions for Dissection of Ann and Right Axillary Region, 94 XXV. Cutaneous Nerves of Arm and Forearm, '.'7 XXVI. Superficial Veins of Front of Arm and Forearm Km XXVII. Superficial Veins of Back of Forearm and Hand, 101 XXVIII. Superficial Lymphatic Vessels and Glands of Front of Upper Extremity, 105 XXIX. Brachial Artery and Biceps Muscle, IK) NXX. Brachial Artery and Branches Ill XXXI. Biceps Muscle, 115 XXXII. View of Arm Biceps Removed, 118 XXXIII. Lines of Arteries of Upper Extremity and of Median and Ulnar Nerves, 122 XXXIV. Bicipital Fascia and Vessels and Nerves at Elbow, 128 XXXV. Triangle of Elbow and Superficial Muscles of Forearm, 131 XXXVI. Triangle of Elbow, Flexor Sublimis Digitorum Muscle, Radial Artery, and Radial Nerve, 135 XXXVIT. Deep Flexor Muscles. Radial Artery and Nerve, Ulnar Artery and Nerve, and Median Nerve, 140 XXXVIII. Arteries and Nerves of Front of Forearm, 141 XXXIX. Arteries of Forearm and Hand, 145 ix x LIST 01' 11. /. I > 77,'. I 770AX I'I.ATK TA'.K XL. Incisions fin- Dissei-tinn of Hand 150 XLI. Superficial Palmar l-'asria i:>:' } XLII. Deep Palmar Fascia and Palmaris Brevis Muscle ].v, XLIII. Superficial Palmar Arch and Di.irital Nerves 159 XLIV. Arteries and Nerves of Front of Forearm, 163 XLV. Fibrous and Synovial Sheaths of Flexor Tendons, ir,r, XL VI. Insertion of Lumbrical and Interosseous Muscles, lo'.i XLVII. Deep Palmar Arch and Interosseous Muscles, J7:; XLVIII. Lines of Arteries Palm of Hand, 170 XLIX. Arteries of Hand, 177 L. Cutaneous Nerves of Arm and Forearm, 181 LI. Musculo-spiral Nerve and Superior Profunda Artery, ls4 LII. Muscles of the Back of the Scapula and Arm 185 LIII. Superficial Veins of Back of Forearm and Hand 190 LIV. Superficial Muscles of Back of Forearm, l'.)4 L\'. Deep Muscles of Back of Forearm, Posterior Interosseous Artery and Nerve, . . . 200 LVI. Anterior and Posterior Interosseous Arteries, 203 LVII. Tendons and Arteries of Back of Hand, 200 LVIII. Sterno-clavicular Joint Anterior and Posterior Views 214 LIX. Scapnlo-clavicular, Aeromio-elavicular, and Scapulo-hnmeralJointa Anterior View. 2 Is LX. Scapulo-clavicular and Acromio-clavicular Joints, and Glenoid Ligament, 219 LXI. Elbow Joint External and Internal Views, 225 LXII. Interior Iladio-ulimr Joint Anterior View, 230 LXIII. Inferior Radio-ulnar, Radio-carpal, Intercarpal, and Carpo-metacarpal Joints- Posterior View, 231 LXIV. Inferior Radio-ulnar, Radio-carpal, Intercarpal, and Carpo-metacarpal Joints Anterior View 2:;:> LXV. Section of Joints of Wrist and Hand, 239 LXVI. Metaoarpo-phalangeal and Interphalangeal Ligaments (Middle Finger), 244 LXVII. Dislocated Shoulder and Normal Shoulder, 249 LXVI 1 1. Skiagraph of Fetal Skeleton. By M. I. Wilbert 257 LXIX. Displacement in Fracture of the Middle of the Clavicle, 20S Fracture of Anatomical Neck of Scapula, 2(iS LXX. Fracture Through Surgical Neck, 272 Fracture Above Insertion of Deltoid Muscle 272 LXXI. Fracture Below Insertion of Deltoid Muscle 270 Colics' 1'Yacture, . 270 LXXII. Transverse Section of Forearm Just Below Middle, 280 LXXI 11. Transverse .Section of Arm Below Insertion of Deltoid Muscle, 290 LXXIV. Transverse Section of Arm Above Cundyles of Humerus, 2U1 LXXV. Aneurysmal Varix ; Varicose Aiieurysin ; Method of Antyllus ; Hunter's Method ; Brasdor's Method ; Wardrop's Method 295 LXXVI. Lines of Arteries of Upper Extremity and of Median and Ulnar Nerves, 300 LXXVII. Lines of Incisions for Ligation of Arteries and Stretching of Nerves, 301 LXXVIII. Operations for Exposure of Third Part, Axillary Artery, and Large Branches of Brachial, Brachial Artery and Median Nerve at Middle of Arm, and Ulnar Nerve in Lower Half of Arm, 316 LXXIX. Axillary Artery and Large Branches of Brachial I'lexus Third Portion, 317 LXXX. Brachial Artery and Median Nerve at Middle of Arm, 319 LXXXI. Ulnar Nerve in Lower Half of Arm 321 LXXXIt. Diagram of Collateral Circulation, 324 I, XXXIII. Diagram of Collateral Circulation, * 325 LXXXIV. Brachial Artery and Median Nerve at Elbow, Radial Artery and Radial Nerve at Middle of Forearm, Radial Artery in Lower Third of Forearm, and Ulnar Artery and Nerve Above Wrist, 328 LIST OF ILLUSTRATIONS. xi PLATE LXXXV. Brachial Artery ami Median Nerve at Elbow, 329 LXXXVI. Eladial Artery and Nerve at Middle of Foreann, 331 LXXXVII. Radial Artery Above Wrist, 333 LXXXVIII. Ulnar Artery and Ulnar Nerve Above Wrist, (35 LXXXIX. Incision for Radial Artery in "Snuff'-box,"' 337 XC. Radial Artery in " Snuff-box," 339 XCI. Posterior Circumflex Artery and Circumflex Nerve, :;il XCII. Subscapular Artery, Middle and Lower Subscapular Nerves, 343 XCIII. Musculo-spiral Nerve Above External Condyle of Humerus, 345 XCIV. Musculo-apiral Nerve Above External Condyle of Humerus 347 XCV. Median Nerve Almve Wrist, 349 XCVI. Surface .Marks of Back, 353 XCVII. Lordosis ; Normal Curve ; Kyphosis; Lateral Curvature, 358 XCVIII. Early Lumbar Caries, Normal Curve Effaced ; Normal Curve ; Advanced Dorsi- lumbar Caries, Angular Curvature 359 XCIX. Relation of Viscera of Thorax and Abdomen to Bony Prominences of Back, . . . 363 C. Incisions for Dissection, 305 CI. Cutaneous Nerves of Back, :;r,',t CII. Muscles nl' Back 373 CIII. Post-scapular Muscles and Triceps Muscle, :;>i CIV. Anastomoses of Arteries Around the Scapula, 385 CV. Subseapularis Muscle and Subscapular Triangle, 390 CVI. Serratufi Magnus Muscle, 391 CVII. Muscles of Back 396 CVIII. Deep Muscles of Back 397 CIX. Suboccipital Triangle, 40C, CX. Ligaments of Spinal Column, 4];>, CXI. Occipito-atlantal and Atlanto-axuiilean Ligaments Anterior and Posterior Views, . 417 CXII. Lmanients in Posterior Surface of Upper Part of Anterior Wall of Spinal Canal, . 421 Central Atlanto-axoiil Joint 42] CXIII. Spinal Veins, 4^;, CXIV. Spinal Cord and Membranes, 4^, CXXI. Incisions for Dissection, 4ti] CXX1I. Layers of Scalp, 463 Cirsoid Aneurysm, 4(53 CXXIII. Superficial Fascia of Scalp, 467 CXXIV. Arteries of Scalp and Face 472 CXXV. Nerves of Scalp and Facial NeiTe, 473 CXXVI. Arteries, Nerves, and Muscles of Scalp and Face, 477 CXXVII. Temporal Fascia and Nerves of Face, 484 CXXVIII. Temporal Muscle 485 CXXIX. Incisions for Dissection and Lines for Vessels and Nerves of Face 487 CXXX. Muscles of Face and Scalp, 4yi CXXXI. Tensor Tarsi and Oorrugator Supercilii Muscles, 496 CXXXII. Arteries of Scalp and Face, 504 CXXXIII. Arteries, Nerves, and Muscles of Seal]) and Face, 505 CXXXIV. Veins of Scalp, Face, and Neck, 509 CXXXV. Palpebral Fissure and Eyeball Eyelids Everted, 513 xii L1XT OF ILLUSTRATION. PAQB CXXXVf. Lacrymal Apparatus and Meibomian (Hands , r )17 ( 'XXX VII. Pinna, 525 CXXXVIII. Intrinsic Muscles of Pinna 527 CXXXIX. Norves of Scalp and Facial Nerve, 531 CXI/. Operation for Exposure of Facial Nerve, iVlii CXLI. Temporal Fascia and Xorvos of Face f).",7 CXLII. Pterygoid Musi-les and Internal Maxillary Artery, ">42 CXI, II I. [nternal Maxillary Artery and Branches 54(i CXLIV. Inferior Maxillary Xerve 550 CXLV. Olfactory Nervos ami Internal View of the Spbeno-palatine and ( (tie (lanulia, . . 554 CXLVf. Superior and Inferior Maxillary Nerves 559 CXLVII. Diploic- Veins S(V. CXLVI1I. Pnra Mater, Arachnoid, and MeniiiL'eal X'essels, :"i7.'> CXLIX. Sinuses and Prore.-se- of I'lira Mater 57S CL. Sinuses and Cranial Nerves 579 CLI. Lines for Sinuses, 585 PREFACE. This book has been twelve years in preparation. During this time, while 1 no change has been made in its plan, its scope has been much enlarged, to meet a wider field than for which it wa.s first intended. My original purpose was to furnish for students a text-book of Surgical Anatomy, then much needed and not obtainable by them. 1 have made a book which will be serviceable, I hope, not alone to them, but to practising physicians and surgeons. While, I regret to sav, this subject is much neglected in our American institutions, there came to be, nevertheless, during the progress of this work, an increasing and encouraging recognition of its importance. In some schools the course was much enlarged ; in others new courses were established. In my own classes the work has constantly grown, until it has become not alone an adjunct to, and application of, descriptive anatomy, but rather the bridge bet ween that study and practice of surgery itself. To meet these requirements it has not been sufficient for me to emphasize and clarify the facts of descriptive anatomy as required of undergraduates. I have been compelled to bring to them the knowledge of anatomy which I have used and as I have used it in surgical practice. My book has kept pace with this change and growth. I have in no case cut down descriptions nor the teaching devoted to surgical anatomy, nor directions for and procedure in dissection, but I have added much relating to surgical work. I have endeavored to regard fully the necessities of undergraduates, and at the same time have had in mind constantly the requirements which they will meet as surgeons in their chosen field, and have tried to make for them a sufficient work of reference for use in actual practice. I am aware that much of the ground, particularly that portion relating to regional anatomy, has been covered by other books. The valuable works of Cunningham, McLaughlin, Holden, Treves, Heath, Owen, and others, the companions and guides of many years, have been at my hand for constant refer- ence. I welcome this opportunity to acknowledge my great indebtedness to them. I have hoped, gathering freely from every source, adding much from surgical xiii xv cx|icrience, and arranging the whole as systematically as possible. In make for tlie student and practical doctor a work of reference which is. comparatively speaking. complete. The illustrations have been for the most part made from dissections, and are, therefore, original and accurate. Too much praise can not lie given the artists and engravers who have expended in their production infinite care and an interest which has been most conscientious. I believe that vise Avill lead to appreciation of the great value of their labors. I take this opportunity to thank, and acknowledge the services of. Or. Carl Ilamann, my old student and house surgeon, now Professor of Anatomy in the Western Reserve University, Cleveland. Ohio, for reading the manuscript; Dr. J. Rex Hobeusack, formerly my prosector in the University of Pennsyl- vania, for the excellent dissections from which the illustrations were made and for other valuable services in the preparation of this book, and Dr. A. 1). Whiting, for making the index. 1034 WALNUT STREET, PHILADELPHIA. SURGICAL ANATOMY. UPPER EXTREMITY. SURFACE AXATOM}' <)! Till'. l'I'l'l-:i! KX'HIKMITY. Divisions. Tin- upper extremity is divisible into the shoulder, tht. 1 urni. the forearm, the wrist, and the hand. The Articulations to he studied are the xlimilili'i- .- the ilium-; the xiijH-ri'ti' and iuj'i-i'ini- r/iilin-iiliiiir : the rinlin-i-iii-jiii/. or irrixt : the coppo-metacarpal ; the mihu-iir/iii-jiliii/iiiii/i'ii/. of which there are live; and the jilt/s of the scapula, forming the hony arch of the shoulder, is not so easily distin- guished. This prominence, formed by the hony arch of the shoulder, must not he confounded with the roundness of the shoulder, which is occasioned by the threat er tuberosity and head of the humerus and the superimposed deltoid muscle. After amputation at the shoulder-joint the prominence of the shoulder remains, but the roundness is lost, owing to the removal of the upper end of the humerus. The relation of these bony points is important in the diagnosis of dislocations of the head of the humerus. A "deltoid tubercle" is sometimes present at the outer one-third of the clavicle, and must not lie mistaken for an exostosis. The infra-clavicular fossa. This is a depression seen immediately below the middle of the clavicle, and corresponds to the interval between the origins ol the pectoral is major and deltoid muscles. It is less evident in muscular per- sons than in those not so well developed. The coracoid process does not give rise to any visible external eminence, except in very thin persons, but can be palpated by introducing the finger into the infra-clavicular fossa and displacing the anterior border of the deltoid upward and outward. The acromion process and the spine of the scapula are subcutaneous and very prominent. The acromion may consist of one or two separate pieces which have failed to co-ossify with the spine of the scapula ; so that there may be one or two epiphyses, which, if incompletely united with the rest of the bone, might be mis- taken for fragments of a fractured acromion. The cpiphyscs. if present, will be found on both sides, while it would be rare to find a fracture on more than one side. Tin' angle formed by the acromion process and the spine of the scapula is readily made out, and affords a convenient point from which to measure in com- paring the lengths of the arms. In taking these measurements, the lower points selected are the external condyle of the humerus and the tip of the styloid process of the radius. The two arms should, it is needless to mention, be placed in the same position. PLATE I. UPPER EXTREMITY- FOREARM PRONATED. 20 PLATE II UPPER EXTREMITY- FOREARM SUPINATED, SHOWING ULNAR DEFLECTION. 21 PLATE UPPER EXTREMITY- LANDMARKS OF ANTERIOR SURFACE. 24 PLATE Dimple over head of radius Subcutaneous portion of ulna UPPER EXTREMITY-LANDMARKS OF POSTERIOR SURFACE. 25 SURFACE ANATOMY <>b' THE ri'l'Ki; EXTREMITY. '11 The biceps muscle stands out as a well-rounded prominence mi the anterior surface <>!' the aria. It is limited <>n cadi side by a more or less well-marked groove. The internal groove contains the principal vessels and nerves of the arm : the outer, the cephalic vein. The deltoid muscle can he easily recognized covering the greater tuherosity of the humerus. Paralysis and subsequent atrophy of this muscle will cause part (if the roundness of the shoulder to disappear. Through this muscle the greater tuherosity of the humerns can he distinctly felt. The prominence immediately helow the aeroimou. anil felt most plainly if the arm he rotated on its long axis, is the greater tuherosity. To the inner side of and a little helow the greater, the lesser luherosity can he felt. By making pressure in a vertical line between these two prominences, the arm being rotated outward and hanging at the side, the bieipital groove, which accommodates the long tendon of the biceps, can be felt. In dislocation of this tendon which, however, is quite rare the groove becomes much more perceptible to the sense of touch. The head of the humerus is most readily felt by inserting the fingers into the axilla. In subgleiioid dislocation of the head it will be felt in the axilla as a very prominent mass. The coraco-acromial ligament is distinctly felt tinder the anterior fibers of the deltoid. The midpoint of this ligament corresponds to the site of the bieipital groove and the long tendon of the biceps. The course of the axillary artery, with the arm at a right angle to the bodv, is indicated by a line extending from a point slightly to the inner side of the middle of the clavicle to the middle of the bend of the elbow. The axilla. The lower margin of the anterior wall of the axilla (the lower border of the pectoralis major) follows the fifth rib. Normally, the glands of the axilla are not palpable. The skin of the floor of the axilla is covered by an elongated patch of hair. In the skin and superficial fascia of the floor of the axilla, are modified sebaceous and sweat glands. These, especially the sebaceous glands, not infrequently become infected, when, if not treated antiseptic-ally, they mav infect the glands of the axilla. These glands are occasionally the site of primary malignant disease. An abscess of the axilla should be opened midway between the anterior and posterior walls, the incision being carried from the arm toward the chest to avoid injuring the large vessels which course along the outer wall. The course of the vessels and nerves of the arm, as in other parts of the body, is along protected routes. They pass from the axilla along the inner side of the arm. thence in front of the elbow, and between the muscles of the upper fore- arm. In the lower third of the forearm they lie near the surface, between the flexor tendons. Upon the digits they lie on the sides, where they are more pro- js SURGICAL .\\ATOMY. i' ctcd. The veins, injury of which is less dangerous than that of either tlie arteries or tlie nerves, are inure superficial. The deep and the superficial veins communicate freely at the joints, thus insuring a free and uninterrupted return circulation during strong and continuous muscular contraction. They have a larger total capacity than the arteries, and this alone is ample reason for the slower How of the venous current. They contain numerous valves, which are necessary on account of the deficient contractile power of the veins. The Mood in them can not recede, liecause of the closing of the valves, which hold it in lock until extraneous muscular contraction or cardiac and vasomotor vis a tergo push the contained Mood forward; or until a change of position favors the descent of the Mood by gravity. The promptness with which the veins are emptied by gravity is quickly and easily demonstrated by the simple experiment of holding one hand over the head while the other hangs loosely at the side. If, after remaining in this position for ahout one-half of a minute, the hands are brought together in front, the previously uplifted one will appear bloodless while the other will show well-tilled vessels. The course of the brachial artery, with the arm at a right angle to the body, corresponds to a line extending from a little to the inner side of ihe middle of the clavicle to the middle of the bend of the elbow. The artery is overlapped by the inner edge of the biceps muscle. It is readily reached in any part of its course, and is easily compressed at its middle, where it lies upon the insertion of the coraco-brachialis, opposite the insertion of the deltoid. The dimple behind the elbow, so much admired in a well-rounded forearm, and so evident in children, who are generally well supplied with fat, is the depres- sion below the outer humeral condyle. It indicates the position of the head of the radius, which can hi' felt rotating when the arm is alternately pronated and supin- ated. In thin persons, and on the back of the forearm while in extreme pnmation, the bicipital tuberosity of the radius can be felt below the head of the radius. The supra-condyloid process is a hook-shaped splenic of bone which occasion- ally projects from above the inner condyle of the humerus. It often gives origin to a third head of the pronator radii teres muscle, which covers the brachial artery. This process must not he mistaken for an exostosis ; it is the rudiment of a process of hone which forms the supra-condyloid foramen in some of the mammalia. In these animals the foramen transmits the brachial artery and the median nerve. Bursaeare present over the olecranon, the baek of the upper end of the ulna, and each condyle. The condyles and olecranon. The bony prominences at the elbow are important in the diagnosis of fractures and dislocations occurring in this locality. These prominences are the internal and external condyles of the humerus and the PLATF. V. ^vl" DISLOCATED SHOULDER AND NORMAL SHOULDER 29 SURFACE .\.\ATOMY OF THE ('/'PER EXTHEMITr. :!1 olecranon process of the ulna. In their normal condition, with the forearm fully extended, tin- tij) of the olecranon and the two condylcs lie in the same transverse line. If the forearm he Hexed, the oleeranon process will lie helow a line drawn from one condyle to the other. The vertical limits of the elbow-joint are indi- cated above by an intercondyloid line; below, by the lowest part of the head of the radius. Extreme elbow llexion arrests the flow of blood in the braehial artery below this joint. THE FOREARM AND WRIST. The ulna is subcutaneous along its posterior border throughout its entire length, when the forearm is supinated, hut, in pronation, the muscles of the back of the forearm overlap the ulna and obscure it. Irregularities of the posterior border of the shaft are, therefore, very readily detected during snpination. The radius is so enveloped by muscle in its upper half that, with the exception of its head, it is beyond reach; but in its lower part it is quite accessible, being even subcutaneous at its lower end. The lower end of the radius extends further downward and forward than does that of the ulna. The course of the radial artery corresponds to a line extending from the middle of the bend of the elbow to the inner side of Ihe base of the styloid process of the radius. The artery is overlapped in its upper one-ln/If by the snpinator longus muscle. To reach it at this part of its course it is therefore necessary to displace the inner edge of this muscle outward. The ulnar artery takes a curved course, which may be represented by two lines: The line for the upper one-third of the artery is drawn from a point one- half of an inch below the middle of the bend of the elbow to the inner border of the forearm at the junction of its upper with its middle one-third ; the line for the lower two-thirds of the artery is drawn from midway between the internal eondyle and the middle of the bend of the elbow to the radial side of the pisiform bone. In consequence of the superficial location of the arteries of the upper limb, and their occasional anomalous course, their exact position should be ascertained by digital palpation before the skin is incised. Study of the front of the carpus reveals the following points : The tubercle of the scaphoid, below the styloid process of the radius and to the inner side of the thumb extensors ; the trapezium, a little below the tubercle of the scaphoid; the pisiform bone, just below the ulna 011 the palmar surface, at the base of the hypoth- enar eminence ; the cuneiform bone, upon the inner side of the pisiform ; several transverse furrows in front of the wrist, the lowest of which marks the upper edge of the anterior annular ligament and the line of the intercarpal joint; the :\-2 SURGICAL AXATO.MY. tendons, when the wrist is flexed : the pulsation of the radial artery where it lies on the outer side of the llexor tendons (between the tendons of the snpinator longus and flexor carpi radialis) ; the tendon of the flexor carpi ulnaris. \vhieh overlaps the nlnar artery, thus masking its pulsation. The level of the radio- earpal, or wriM. joint eorresponds to the interval hetween the styloid process of the radius and the tubercle of the scaphoid. Incision- into the front of the wrist for the evacuation of pus should he made upon the ulnar side of the llexor carpi radialis tendon, and rather close to it, so as to avoid the radial artery, externally, and the median nerve internally, which lies a little to the ulnar side of this tendon. Too deep an incision may enter the flexor sheath or great carpal hnrsa. The pulse. The pulsation of the radial artery in front of the lower end of the radius, upon the radial side of the flexor carpi radialis tendon, is commonly known as the " pulse." Sometimes the superficialis vohe arises high up and descends with the radial, thus giving the impression of a donhle pulse (pulsus duplex). At other times the radial artery turns backward over the radius higher up than usual, and then the- pulse is not found in its normal position. "The anatomic snuff-box" is a designation given by the French to the space upon the radial side of the hack of the wrist hetween the iirst and second tlmmh extensor-!. It is hounded ahove hy the styloid process of the radius, helow hy the base of the metacarpal hone of the thumb, upon the radial side by tin 1 tendons of the extensor ossis metacarpi pollicis and extensor primi internodii pollicis, and upon the ulnar side by the tendon of the extensor secundi internodii pollicis. In it are found the superficial radial vein ; the radial artery, as it dips forward into the first interosseous space to form the deep palmar arch ; and the base of the first metacarpal bone. The artery gives off in this space the posterior carpal, the iirst dorsal interosseou-. the dor-ales pollicis. and the dorsalis indicis artery. " Tenalgia crepitans " is the name given to a grating sensation present at the back of the wrist in synovitis of the sheaths of the extensor tendons of the fingers thecitis and in the dryness accompanying uric acid disease. THK HAND. The palm of the hand presents two eminences, a depression, and three furrows. The eminences are the thenar the ball of the thumb and the hypothenar. The thenar eminence is produced hy the short muscles of the thumb, and the hypoth- enar eminence by the short muscles of the little 1 finger. The thenar eminence is situated at the base of the thumb, and the hypothcnar at the base of the little finger. The depression of the palm or hollow of the hand is triangular in shape. The ba>e of the triangle is formed by the elevations at the roots of the lingers, the sides by the PLATE PRINCIPAL FLEXOR FURROWS. 34 PLATE VII, Radial a. Superficial volae a. Pnnceps pollicis a. Radialis indicis a. Digital a. Interosseous a. Ulnar a. Deep branch of ulnar a. Deep palmar arch Line for deep palmar arch Superficial palmar arch Line for superficial palrhar arch PALM OF HAND -LINES OF ARTERIES, 35 SURFACE AXATOMY OF THE I'lTER EXTREMITY. 37 thenar and hypothenar eminences, and the apex by the junction of the thenar and hypothenar eminences. The palmar flexor furrow is composed of two parts, an ulnar and a radial. The ulnar part (convex upward) extends from in front of the head of the fifth ineta- carpal bone to the web between the index and middle ringers, and the radial part (convex downward) extends from in front of the head of the inetaearpal bone of the index finger to the hypothenar eminence. When the fingers are flexed, the trans- verse portions of these furrows form a deep fissure with a central interruption. This fissure indicates the position of the heads of the mctacarpal bones ; the upper limits of the synovial sheaths of the flexor tendons of the index, middle, and ring lingers: the division of the palmar fascia into four slips, and the transverse meta- carpal ligament; while a little below it the digital arteries bifurcate into their terminal branches. An arched furrow also extends around the base of the thenar eminence from the outer end of the radial portion of the palmar flexor furrow to the base of the thenar eminence. It is placed opposite the carpo-metacarpal joint of the thumb; this relation is analogous to that of the other two furrows to the metacarpo-phalangeal joints. If the meta carpal bone of the thumb be viewed as the first phalanx, which it is from a developmental point of view, the analogy is more complete, all three furrows marking the position of the basal articulations of the primary phalanges. On the palmar surface of the finger there are three transverse furrows; the last two locate the position of the interphalangeal joints, the first furrow being nearly midway between the metacarpo-phalangeal and the first inter- phalangeal articulations. With the thumb strongly abducted, a line drawn from its lower border trans- versely across the palm of the hand represents, for all practical purposes, the lowest point in the course of the superficial palmar arch. A line drawn one-half of an inch to the proximal side of that for the superficial arch, and parallel to it, repre- sents the course of the deep arch. The interosseous arteries, both dorsal and palmar, run along the interosseous spaces, thus making it desirable when opening abscesses of either the front or back of. the hand to carry the incision over the inetaearpal bones rather than over the interspaces. The sesamoid bones of the thumb lie just beyond the metacarpo-phalangeal joint, that is, to its distal side, so that in amputation through the joint the incision into the articulation should be made on the proximal side of these bones. The knuckles, consisting of three rows, are formed by the distal ends of the proximal bones. Thus, the heads of the metacarpals form the first, the distal ends of the first phalanges the second, and the distal ends of the second phalanges the 38 SURGICAL A \ATOMY. third, row. To enter the knuckle-joint for amputation the knife should be carried a little in advance of the prominence of the knuckle. NERVE STKKTCIIIXC AND NKRVK SICCTIOX have now become so well-recog- ni/ed and common procedures that the following tew instructions may he an aid to the student, both in retaining his knowledge of the anatomic relations and in subsequent practical surgical utility: The inlii-i (i.i-;!liit'rM- and reapplied when discontinuing. In reflecting the skin it is advisable to make as large flaps as possible. My reason is a two-fold one : first, there is no better covering than the skin to preserve the moisture of the underlying structures ; and, second, the dissector is thus enabled to review the surface anatomy of the part, from time to time, and study carefully the relations of the surface markings to the deeper structures. In removing the skin from the front of the chest no more than three incisions are, therefore, advisable: one extending along the middle of the entire length of the sternum, another from the upper end of this incision along the clavicle to its acromial end, and thence downward over the shoulder to the outer side of the middle of the arm, and a third from the lower end of the sternal incision transversely outward to the line of the posterior fold of the axilla. -4S sritdirAL AXATOMY. Now grasp only tlie skin at the superior sternal angle with a pair of forceps and gradually relied it by severing it.- e(innecti(iii to the underlying fascia with a knife; but as soon as enough has lieeii turned hack to he readily grasped by the lingers, they should take the place of the forceps, because the work thus becomes easier and is more rapidly and more neatly executed. The superficial fascia and its nerves and vessels thus become exposed, though in the infra-clavicular and shoulder regions there will he seen a thin layer of muscular libers passing over the clavicle into the neck. This is the origin, or inferior attachment, of the platysma myoides muscle, a superficial structure by which the skin of the neck is moved. It is a remnant of a well-marked and useful structure the pannim/nx rarnoxnx a thin layer of muscular libers existing in the lower animals; it is situated in the superficial fascia, and enables its possessor to shake off flies and other insects by rapid vibratory motions of the hide. It is the underlying red muscular structure which one sees in fancy figures cut in (|iiarters of beef and mutton. A slash of the knife immediately after skinning causes a wide separation of the severed ends of the still warm muscular fibers, which contract as soon as cut. The skin over the sternum is rather thicker than over the lateral regions of the thorax, can not readily be raised up in folds, and retracts considerably when divided. In males it is often covered with a growth of hair. Keloid growths arc not uncommonly seen here. The superficial fascia consists of both a superficial layer of connective tissue. quite rich in adipose substance, occupying its meshes, and a layer, which is membranous and resembles the deep fascia to which it is attached. Met ween the two layers are found the mammary gland, the vessels, and the nerves. Over the sternum the adipose tissue is less abundant than elsewhere in the anterior thoracic region; and in corpulent persons, therefore, the sternal area is relatively depressed. The fascia is firmly adherent to the periosteum of the sternum. The vessels of the superficial fascia are as follows: Five or six jierforatin;/ branches of the intermit nunnniai-i/ a i-fe i- 1/. which appear near the sternum and are directed outward, the upper three usually going to the mammary gland and becoming enlarged in women during lactation, the lower two or three' supplying the pectoralis major. The upper five or six imtn-im- mtffrcostal branches of the internal mam tnary also appear upon the front of the chest to supply the pectoral muscles and the mammary gland. Thoraeie liraneliex nf fin 1 acromio-thoracic artery two or three small vessels descend upon the chest at the middle of the clavicle to supply the pectoralis major and anastomose with the preceding. The aei'mnial branches of the same go to the shoulder and supply the deltoid ; they anastomose upon the top of the shoulder with the supra-scapular and posterior circumflex arteries. The descending branches pass down the delto-pectoral sulcus beside the PLATE XII, Branch of transversalis colli a. Branch of acromlo-thoracic a Branch of lonp thoracic a.- Mammary gland in superficial fascia Perforating branches of internal mammary a.- SUPERFICIAL FASCIA OF PECTORAL REGION. 49 PLATE XII. Serratus magnus m. lateral Cutaneous Latissimus dorsi m.- External oblique m. Internal oblique m. in triangle of Petit v ectoralis major m. Lineae Transversae Linea Semilunaris Anterior cutaneous nerves ANTERIOR CUTANEOUS AND LATERAL CUTANEOUS NERVES. 62 SURFACE ANATOMY OF Till-: I'l'I'KR KXTIIKMITY. '>''> cephalic vein. Tin- /-///// tlim-m-ir iniii-i/ scnls branches to tlie mammary gland and (lie superficial fascia. All of these vessels supply the fascia and skin of this region, and are accompanied by veins and lymphatics, which latter become visible during inflammatory diseases. The nerves in the fascia of this region are branches of the cervical plexus and the intcrcostals. The cervical plexus sends down inner or Kiij>rii-sti nut/ l>r protect the nipple during suckling. These glands may be primarily all'ected by carcinoma or sarcoma, which may secondarily involve the mammary gland. The skin of the nipple is thin and very sensitive, and i- ot'ien the seat of ])aint'ul and intractable lissures during nursing. Chronic inflammation of the skin of the nipple (ec/eina) is at times the accompaniment of beginning Paget's disi mammary epithelioma, and cancer of the lnvaM. BI.OOD AND XKKVK Srn-i.Y. The niammary gland is nourished by the long thoracic.- branch of the uj-illm-ii artery, the unl/rior intercostal, and, especially, the /irii'iii'iiti/ii/, branches of the internal mammary artery, and the hif< irnxldl. artc'ries. The veins accompany the arteries and also form an anastomotic circle about the nipple (circulus venosus, Haller), from which large branches carry its contents to the circumference of the gland, whence it is taken to the axillary and internal mam- mary veins. The lymphatic channels play a conspicuous role in inflammatory and neo- plastic processes. Most of the mammary lymphatics go to the axillary glands, though a few enter the anterior mcdiastinal lymphatics, following the mammary branches of the internal mammary artery. When the breasts are unusually large, the lymphatics communicate across the sternum ; this is one of the anatomic' explanations of the occurrence of cancer in both breasts. In advanced cases of carcinoma of the breast the glands in the infra- and supra-clavicular fossae often become involved, in addition to the axillary glands. The lymph from the mam- mary gland first passes into the glands along the anterior fold of the axilla and then into those along the axillary vessels. As metastasis from cancers follows the course of the lymphatics, the glands along the anterior fold are first involved and ' then those along the axillary vessels are affected. In its course the lymph will, after a time, involve the glands along the subclavian vessels. The anastomosis between the submammary lymphatics and the intramammary lymphatics is so free that the operation for carcinoma of the breast which promises the best results is that which removes the entire gland, the skin wide of the diseased area, totally excises the submammary and paramammary connective tissue, the pectoral fascia, sternal portion of the pectoralis major, the pectoralis minor, the lymphatics and connective tissue of the armpit, deep infraclavicular and subclavian triangles. The lymphatics of the axilla, deep infraclavicular triangle, and subclavian tri- angle are not necessarily involved through the superficial lymphatic channels, but may be directly infected through the submammary lymphatic vessels. If the axillary vein be wounded in the operation for removal of the breast, a small opening may be closed by pinching up the torn place and applying a lateral r,S SriiCK'AI. AX ATOMY. ligature; but if the wound be large, tbe vein must be tied to either side of the rent. When the axillary vein is included in malignant tissue, ligatures should be applied above and below and the involved portion of the vein excised. The nerve supply is from the n/tlrr/nr cutaneous /'i-i/nr/nx of the third, tburili. and fifth intercostal, the ilrxccitil'nuj branches of the cervical plexus, and the lateral cutaneous branches of the third, fourth, and fifth inteivostals. This arrangement of the nerves explains the pains tell in the shoulder, neck, back, and down the arm in painful breast affections, such as cancer, mastitis, and ab external mammary in contradistinction to the .niju-rjicinl external mam- mary, which is not constant. The superficial external mammary is a branch either of the third division of the axillary or of the first portion of the brachial, and reaches the gland by passing through the superficial fascia of the axilla. Because of the close relation which this gland bears to the pectoralis major muscle, all movements of the arm affect the gland, more or less. This is not particularly noticeable, ordinarily, but it becomes unpleasantly evident in painful affections of the breast, as in mammary abscess. Mammary abscess may be confined between the septa of the gland, may be diffused throughoul the organ, or may occur in ihe submammary connective tissue ; in this last event it will most likely point at the anterior fold of the axilla. Inci- sions into the breast should be made toward the nipple, so as not to sever the lactiferous ducts whicli converge toward this point. After opening an abscess of the mammary gland, the fibrous septa of the abscess should be broken down in order that perfect drainage may be obtained. After all operations upon the mammary gland, and in the treatment of inflammatory affections of the gland, the whole upper extremity should be bandaged to the chest as in fractured clavicle, so that movements of the arm and pectoralis major will not prevent rest of the part. Enlargement of the bursa under the breast would constitute a submammary cyst. In long-standing scirrhus (hard cancer) of this gland the nipple is retracted and the skin dimpled, because of traction by the fibrous septa and lactiferous ducts. In detecting adhesions between the mammary gland and the pectoralis major, as in carcinoma of the breast, the gland should be moved in the direction of the libers of that muscle ; for if the gland is moved in a direction which is across that of the fibers of the muscle, the pectoralis major will move with the gland. A suspected tumor in the mammary gland is most readily detected by placing the palm of the hand flat upon the organ and compressing the latter against the thorax. If the enlargement be inflammatory, the hand feels nothing but the lumpy and wormy sensation of the swollen ducts and acini. This is Spence's test. PLATE XV, .ial fascia -h of lateral cutaneous n. Intercosto-humeral n. ephalic v. Deep fascia Axillary fascia DEEP FASCIA OR. PECTORAL FASCIA AND AXILLARY FASCIA. 59 PLATE XVI, Clavicle. Costo-cnracD/d mem,- Pec fora /is major Teres major. faffss/mus -dors/, --Subscapularis. es major. -Latissimus dorsl. fliagrsm shnwing line of section. DIAGRAM OF PECTORAL FASCIA AND AXILLARY FASCIA. 62 Xl'ltl-'ACK ANATOMY OF THE UTTER EXTREMITY. (>'"> Congenital variations and anomalies of the breast. The nij)])k> may lail to develop properly, and thus appear, in the adult, to be retracted. Absence of the nipple (uilii'liit) is sometimes observed. When supernumerary nipples occur, the condition is spoken of as po!i/tlioneurosis 'u if ff the costo-coracoid membrane, the subclavian vessels, and hrachial plexus of nerves. I'.i.ooh Srri'LY. From the clavicular hrancli of the acromio-thomcic artery. Ni:i;vK Sri-i'LY. A filament from the cord formed by the tit'th and sixth cervical nerves. ACTION. It depresses the shoulder by pulling the clavicle downward and forward. It also draws the clavicle inward, holding the inner extremity of the bone against the sternum. J>issKrtin of the ir.ri//i artery, the *n/x rim- thoracic and aeromio-thoracic mier/ex a ml veins, the terminal jxiiiivn of the cephalic rein, the e.ilei'nuf unr ln-< 7//W jilcjnx, and the /mx/crim- < long thoracic nerre. These structures will be described under the dissection of the axilla, as they can be studied to better advantage at that time. DISSKCTION. The remaining or chondro-sternal portion of the pectoralis major should now be severed in the middle and reflected, when will be exposed the pecto- ral ix minor enveloped by the deep layer of the deep or pectoral fascia. The internal antfi-ini- thni-iteii' nerve should be observed as it passes from the pectoralis minor to the pectoralis major. The fascia may then be removed from the pectoralis minor. The pectoralis minor muscle is of an elongated triangular shape, and arises at its base from the anterior extremities of the third, fourth, and fifth ribs, and the intervening intercostal fascia. Its fibers pass upward and outward, to be inserted by a flat tendon into the anterior half of the inner surface of the coracoid process of the scapula and the upper part of the tendon of the coraco-brachialis 71 SURGICAL A \.\TDMY. muscle. It lies behind, and in contact with, tlic pectoralis major, between (lie two lamella 1 of the deep layer of the pectoral fascia, and immediately in front of the axillary contents. Its upper and lower margins divide the axillary artery, over which it passes, into three parts, the first portion being above, the second behind, and the third below, the muscle. It is supplied by the superior or short thoracic and long thoracic arteries, which pass along its upper and lower border* respectively. It receives its NKKVK Sri'i'i.Y from the internal anterior thoracic nerve, which pierces it to enter the under surface of the pectoralis major. ACTION. It draws the shoulder downward and forward, but does not draw it inward, as is so generally stated, because, though tending to do so, the clavicle prevents. If the shoulder were fixed well forward, it could act as a powerful inspiratory muscle. DISSECTION. This muscle should now be severed through its middle and reflected as far as its attachments, thus exposing the whole axilla to view. Upon the opposite side of the body the axillary contents should be dissected from below upward without disturbing the pectoral muscles, access to (lie axilla being gained through its base, which is the axillary fascia. It is by this latter route that the surgeon enters in nearly all axillary operations. The study of the axillary eon- tents from these two different directions forms the best method of practically familiari/ing the student with their intricate relations. The axillary fascia. The layer of fascia inclosing the pectoralis minor joins the layer covering the pectoralis major along the lower or axillary border of the latter muscle ; by this union is formed the axillary fascia. It is a dense mem- brane which extends from the lower border of the pectoralis major backward to the latissimus dorsi muscle, and forms the floor of the axilla outward to become con- tinuous with the deep fascia of the arm, and inward to blend with the deep fascia of the chest. Where it meets the latissimus dorsi (posterior border of the axilla), it divides into two layers, which ensheath that muscle and become continuous with the deep fascia of the back. The axilla, or arm-pit, is a pyramidal-shaped space or recess, situated between the upper part of the side of the chest and the upper part of the arm. It has a base, an apex, and four sides or walls. The base directed downward between the free borders of the pectoralis major muscle in front and the tcres major and latis- simus dorsi behind, is formed by the axillary fascia. These borders are known as the anterior and the posterior folds of the axilla. The apex, to the inner side of the coracoid process and directed upward, is bounded by the clavicle, the first rib, and the upper margin of the scapula. Through the apex, which is the point of communication between the neck and axilla, pass the axillary vessels, the brachial PLATE XX. Alar tn Long thoracic a Outer cord of brachial plexus :ord of brachial plexus (displaced* Pectoralis minor m. Musculo-cutaneous n. Subscapular a. Circumflex n. Posterior circumflex a. Coraco-brachialis m.- Dorsalis scapuii a Acromio-thoracic a. Suprascapular n. taternal anterior thoracic n. External anterior thoracic n, ry a. Xrllary v. Subclavius m. Superior thoracic a. ,Clavicular head of pectoralis major m. Short head of biceps m Anterior circumflex a Lower subscapular n Median n. - Deltoid m Triceps m Dinar n. Musculo-spiral n. Lesser internal cutaneous Teres major m Long subscapular n. Subscapularis m. Subscapular a. Posterioror long thoracic n. Latissimus dorsi m. Intercosto-humeral n. Dictation of serratus magnus m. Pectoralis minor m, Chondro-sternal head of pectoralis major CONTENTS OF AXILLA SHOWN BY DISSECTION MADE FROM BEFORE BACKWARD 76 PLATE XXI. CONTENTS OF AXILLA SHOWN BY DISSECTION MADE FROM BELOW UPWARD, 77 SURFACE ANATOMY <>!' Till-: r/V'AV,' KXTllKMITY. 7!) plexus of nerves, and the posterior or long thoracic nerve (external respiratory nerve of Hell). The anterior wall of the axilla is formed by the pectoral and sulicliivius muscles and the clavi-pectoral fascia, and the ]n>sterior by the siib- scapular, the teres major, and the latissimus dorsi muscle. Kxternally the anterior and posterior walls converge. Tin- inner wall is formed l>y the four or live upper ribs, the intervening intercostal muscles, and the corresponding (limitations of the serralus magnus; the outer wall is formed by the humerus, the short head of the biceps, and the coraco-brachialis muscle. The axillary vessels and nerves are in intimate relation with the outer wall of the axilla, and this, therefore, is the most important part of the space. The axilla varies in depth according to the relation of the arm to the side of the chest. It is deepest when the arm is raised at an incline of about forty-five degrees, and shallowest when the arm is strongly abducted. In the position of strong abduction of the arm its contents are brought nearer the surface, and this position, therefore, is the one preferred when operating upon the axilla. When palpating the axilla to determine the position of the head of the humerus, the presence or absence of enlarged glands, etc., the arm should be brought near the side, thus relaxing the axillary fascia and allowing it to be carried in advance of the finger, thereby facilitating the examination. A colld-linn nf jinx within the axilla, if not afforded an ample and thorough outlet, is more likely to point in the neck than at the base of the axilla, as it would meet with less resistance in traveling by way of the apex of the space than in ulcerating through the axillary fascia. Axillary abscess may be secondary to abscess of the neck, owing to the rather free communication between the neck and the axilla. (For the course taken by purulent collections beneath the pectoral muscles and not within the axilla, proper, see description of the arrangement of the layers of the deep or pectoral fascia, p. G3.) When opening the axilla from below for the purpose of giving exit to a purulent or other collection, the incision should be made midway between the anterior and posterior folds, and from without inward, away from the large blood-vessels and nerves which lie along its outer wall. The incision must not be carried too far inward, for fear of wounding the posterior thoracic nerve, which lies along the inner wall of the axilla an accident which would likely he followed, if the nerve were completely severed, by paralysis of the serratus magnus muscle. Again, by confining the incision to the center of the axilla, the long thoracic artery (deep external mammary) on the anterior wall, and the subscapular vessels and long subscapular nerve on the posterior wall, of the axilla will be avoided. The incision may divide the superficial external mammary artery which, when present, runs through the superficial fascia over- lying the axillary fascia. This vessel, if divided, may give rise to enough 80 SURGICAL .\\.\TOMY. bleeding to alarm the operator and lead him to fear that lie has wounded a large hraneh within the axilla. The mutt-nix of the axilla are the axillary vein and its branches; the axillary artery and its l>nmehes; the axillary or hraehial plexus of nerves, and most of its liranehes ; the lateral eutaneons hranehes of the intercostal nerves, that of ihr second being known as the intercosto-huiueral ; the posterior or long thoracic nerve : three chains of axillary lymphatic glands, and a large quantity of areolar tissue and fat. DISSKITION. Fpon the side of the body on which the anterior axillary wall has been rellected the areolar tissue and fat should he removed from the other structures in the axilla in the order in which they have heen enumerated, while upon the opposite side the space should he dissected from lielow upward. The axillary vessels are inclosed by a xJiratii derived from the prevertehral layer of the deep cervical fascia, the anterior wall of which is reinforced hy the eosto-eoracoid memhraiie. The sheath should he removed in order that the vessels may he more clearly exposed. The axillary vein, the vessel accompanying the axillary artery, is the con- tinuation of the hasilic vein. It commences at the lower horder of the tendon of the teres major and passes upward along the outer wall of the axilla as far as the lower horder of the. first rih, where it becomes the subclavian vein. It lies to the inner or thoracic side of the axillary artery. The axillary vein receives the cephalic vein and branches corresponding to those of the axillary artery, with the exception of those of the circumtlex arteries, which may enter either the subscapular vein or one of the vena3 comites of the brachial artery, or the cephalic vein. In the upper part of the axilla the relation between the axillary vein and the axillary artery is more intimate than it is in the lower part. (See Belations of the Axillary Artery, p. 82.) The axillary vein, like the artery, may be said to consist of three portions namely, the first, the second, and the third. The first and third portions of the vein correspond to the third and first portions of the artery respectively. The axillary vein is more likely to be wounded than the axillary artery, as it lies nearer the surface. AVhen the vein is engorged with blood, it sometimes comes into sight sooner than we expect ; and therefore it behooves the operator to be very careful. On account of the size of the axillary vein and its close proximity to the heart, in wounds of the vessel there is danger of air entering the circulation. The adherence of the costo-coracoid membrane to the sheath of the vessel, and of the sheath in turn to the wall of the vein, favors the maintenance of an uncollapsed condition of the vessel. Notwithstanding that experiments have been made to demonstrate that air can be injected into the circulation without producing any SURFACE AXATOMY o/-' THE ITI'I-I; KXTIiKMlTY. *1. deleterious cH'ccts, it is, nevertheless, better to err on the side of safety : conse- quently, when large venous trunks are divided, as in amputation, they, as well as the arteries, should lie separately limited. The danger in including the artery and the vein in the same ligature is the establishment of an nleerative communication lietween the vessels, and a eonsei |iieiit a rterio-veiious aiH'urysm. Again, the divided vein, when not tied, oilers an avenue tor the introduction of septic matter into the eilvulalioii. Pressure upon the axillary vein, as in forward dislocation of the liumerus, from axillary tumors, a crutch, an axillary pad, or enlargement of the lym- phatic glands, may cause edema of the arm and forearm. Kdema of the arm associated with carcinoma of the breast is a grave symptom, because it indicate.* involvement of the deep lymphatics, which are in relation with the axillary vessels. Kdeina appearing shortly after removing the fat and lymphatics of the axilla in excision of the breast is due to a phlebitis, or loss of support previously given the vein by the fat, lymphatics, and pectoral muscles. When opening the arm-pit for the purpose of excising a growth or removing enlarged glands, the incision T recommend is one made along the center of the arm-pit, extending far enough into the arm to expose the first portion of the axillary vein. The dissection should then be made from without inward or away from the axillary vein. IVv following this method there will be less risk of wounding the vein than when working from within outward or from below upward. The practice of removing enlarged glands with the finger, used as a hook, through a comparatively small opening in the base of the axilla is dangerous. The axillary artery, the continuation of the subclavian, commences at the lower border of the first rib. It passes downward and outward through the apex, along the outer wall of the axilla, beneath the greater and lesser pectoral muscles, and along the inner border of the coraco-brachialis to the lower border of the tendon of the teres major, where it becomes the brachial. The course of the vessel through the axilla varies with the relation of the arm to the body. With the arm abducted to a right angle with the body the artery takes an almost straight course, indicated by a line drawn from a point a little to the inner side of the center of the clavicle to the inner side of the tendon of the biceps at the middle of the bend of the elbow ; with the arm carried well upward the artery describes a curve the concavity of which is directed toward the shoulder ; with the arm at the side the artery describes a curve the convexity of which is directed toward the shoulder. Pressure upon the axillary artery, as in forward dislocation of the humerus, may cause absence of the radial pulse. 82 SURGICAL ANATOMY. As the relations of the artery vary in passing through (lie axilla, it is, for convenience of description, divided into three portions the first, second, and third. The first portion extends from the lower border of the first rib to the upper border of the pectoralis minor; the x-f the vessel can be made to encircle it further away from the branches than in either the first or second portions, and thereby interfere less with the establishment of the collateral circulation. This portion of the vessel oilers a favorable point for digital compression against the upper end of the hnmerns or with the linger inserted into the axilla, against the axillary or external margin of the scapula. A muscular slip, passing from the latissimus dorsi to join the pectoralis major, coraco-brachialis, or biceps muscle, and crossing the third portion of the axillary artery, is sometimes present. This should be borne in mind, and the slip should not be mistaken for the coraco- brachialis. THE FIRST PORTION. In front of this portion are the external anterior thoracic nerve, the costo-coracoid membrane, the cephalic vein, the acroinio-thoracic vessels, the axillary lymphatic trunk, and the clavicular head of the pectoralis major; to the inner side and overlapping it when the arm is at the side of the body is the axillary vein ; when the arm is abducted to a right angle with the body, the vein lies entirety to the inner side of the artery ; to the outer side is the brachial plexus ; behind is the first intercostal muscle, the first digitation of the serratus magnns, and the posterior thoracic nerve. It is important to remember the relation between the vein and artery when ligating the first portion of the latter. Its ligation may be beset with difficulties additional to its depth and its varying relations to its companion vein. The causes of these are the occasional entrance of the cephalic into the subclavian vein, thereby crossing the artery at a higher point, the presence of the envelop- ing plexus, formed by the external and internal anterior thoracic nerves, the artery being crossed by one of the roots of the median nerve (Holden) or by the supra-scapular vein which joins the axillary instead of the external jugular. The brandies of this portion are the superior thoracic and the acromio- thoracic. The superior thoracic artery is the first branch 01 the axillary, arising so close to the lower margin of the first rib that it may almost as well be considered, as by some anatomists it is, the last branch of the subclavian. At times it is derived PLATE XXII. Branch of Acromio-thoracic a. Posterior scapular a. Branch of posterior circumflex a. Subscapular a. Suprascapular a. Dorsalis scapulae a ANASTOMOSES OF ARTERIES AROUND THE SCAPULA. 84 SURFACE A.\.\TOMY or Till-: r/'/'/vA' EXTHKUITY. . 85 from tlie aeromio-thoracic. It runs along tin.- upper border of the pectoralis minor to supply both pectoral muscles, the serratus magnus, and the contents of the adjacent inlcreustal spaces. It anastomoses with the intercostal arteries. The acromio-thoratie niii /;/ is a short trunk, or axis, springing from the axillary artery jusl ahove the upper margin of the pcctoralis minor. It gives oil' three divergent branches the thoracic, the acromial. and the descending or humeral and ;;udl twig (clavicular branch) to the subclavins muscle. The thorarir hriitii-lirx (two or three) go lo the pectoral and serratus magnus muscles, and anastomose with the intercostal arteries and the intercostal branches of the internal mam- mary. The iici-nniiii/ l>i-.MY. muscle; wliile behind it are the nmsrulo-spiral and circumflex nerves, the sub- scapularis muscle, and the tendons of the latissinms dorsi and tcivs major. Ils branches arc the subscapular, anterior circumflex, and ] ulterior circumflex. The subscapular //itists of three trunks an upper, a middle, and a lower; in the axilla, of three cords an outer, an inner, and a posterior. The plexus is formed by the anterior divisions of the lower four cervical nerves and first dorsal nerve. The three trunks, seen iu the deep dissection of the side of the neck, are formed as follows : The anterior primary divisions of the fifth and sixth cervical nerves form the upper trunk, the anterior primary divisions of the eighth cervical and first dorsal nerve form the lower trunk, and the anterior primary division of the seventh cervical forms the middle trunk. These trunks lie in relation with the second and third portions of the subclavian artery. The upper and middle trunks lie above the artery, while the lower is partly behind it. These three trunks enter the axilla by way of its apex, lying above and to the outer (acromial) side of the first portion of the axillary artery. Each trunk divides into an anterior and a posterior branch. The anterior branches form the outer and inner cords of the plexus, while- the posterior branches form the posterior cord. The anterior branches of the upper and middle trunks unite to form the outer cord, which lies on the outer side of the second portion of the axillary artery ; the anterior branch of the lower trunk constitutes the inner cord of the plexus, which lies on the inner side of the artery ; the posterior branches of all three trunks unite to form the posterior cord of the plexus, which lies behind the second portion of the axillary artery. Where, as occasionally happens, the poste- rior cord is formed simply by the union of the posterior branches of the upper and middle trunks, the posterior branch of the lower trunk, small in comparison with tin others, unites with the musculo-spiral branch of the posterior cord. Pressure upon the brachial plexus maybe produced by an axillary tumor, an axillary aneurysm, an anterior luxation of the humerus, a fracture of the clavicle, a crutch, or an axillary pad in the treatment of fracture of the humerus. !>o SURGICAL .\\.\To.MY. The pressure causes tingling, numbness, and pain in the upper extremity, and sometimes ]>;ir;ilysis of some ol the muscles of this part of the body. The In-intclit x given otl' from the axillary plexus he-low the clavicle are the external and internal anterior thoracic, the three subscapular, the circumtlex, the musculo-cutaneous or external cutaneous, the median, the ulnar. the internal cuta- neous, the lesser internal cutaneous, and the musculo-spiral. Of these branches the external anterior thoracic, the outer head of the median, and the musculo-cutaneous arise from the outer cord ; the subscapular, the circumtlex. and the musculo-spiral from the posterior cord; and the inner head of the median, the ulnar. the internal cutaneous, the lesser internal cutaneous, ami the internal anterior thoracic from the inner cord. The external or superficial anterior thoracic nerve is derived from the begin- ning of the outer cord, just below the clavicle, passes inward across the axillary vessels, and pierces the costo-coracoid membrane to enter the under surface of the pectorulis major to supply it. It communicates with the internal anterior thoracic nerve. The internal or deeper anterior thoracic nerve, smaller than the external, is derived from the inner cord, just helow the clavicle, and passes forward between the axillary artery and vein, sometimes piercing the sheath of the latter. It enters the peetoralis minor, to which it gives branches, and then pierces it to enter the pectoi-alis major. It gives off a branch which forms, with a branch from the external anterior thoracic nerve, a loop around the inner side of the axillary artery, from which loop pass other branches to enter the peetoralis major. The three subscapular nerves the upper, the middle, and the lower arise from the posterior cord. The upper or short subscapular supplies the upper part of the subscapular muscle ; the middle or long subscapular accompanies the sub- scapular artery and supplies the latissinms dorsi muscle; the lower subscapular supplies the axillary border of the subscapular muscle and the teres major muscle. The circumflex nerve arises from the posterior cord, passes downward and outward behind the third portion of the axillary artery, and over the subscapular muscle to the quadrangular subdivision of the subscapular triangle, by way of which, in company with the posterior circumflex artery, it leaves the axilla. Between the axillary border of the scapula and the teres minor it gives off an articular branch which pierces the capsular ligament to supply the shoulder- joint, after which it divides into a superior and an inferior branch. The xujH'rinr branch accompanies the posterior circumflex artery around the back of the surgical neck of the humerus and under the deltoid to its anterior border, supplying this muscle and the skin over its lower part. The infirim- brnncl* sends twigs to the back part of the deltoid, and one, -with a gangliform enlargement, to the teres SURFACE A* ATOMY <>F THE I'l'I'Mt EXTHEMtTY. !M minor, after which it passes under the deltoid and around the lower part of its posterior border lo supply the skin over the long head of the trieeps and the lower two-thirds of the posterior part of the deltoid. A fiiri/iitul. In-tnn-1/ arises from the end of the ehvumflex nerve and passes up the hieipital groove to supply the tendon of tlie long head of the hiceps, the upper end of the humerns, and the shoulder-joint. The musculo-cutaneous or external cutaneous nerve is the continuation of the onter eord. It begins opposite the lower border of the peetoralis minor, lying close to the outer gide of the axillary artery. It then passes outward and down- ward to the eoraeo-braehialis muscle, which it pierces and supplies, undergoing subdivision in its substance. The median nerve is formed at the outer side, or in front, of the third portion of the axillary artery hy the Y-shaped union of its two heads, the external and internal. The external head arises, with the musculo-cutaneous, from the outer coid; the internal head, with the ulnar, from the inner cord. The internal head crosses iii front of the third portion of the axillary artery. The ulnar nerve is the continuation of the inner cord. It lies upon the innei side df the third portion of the axillary artery, between it and the axillary vein, and then passes down the inner side of the arm upon the inner surface of the trice) is. The internal cutaneous nerve arises from the inner cord and passes downward on the inner side of the axillary artery, between this vessel and the ulnar nerve. The lesser internal cutaneous nerve (nerve of Wrisberg), the smallest brand) of the plexus, arises from the inner cord, passes behind the axillary vein and then along its inner side, where it is joined by the intercosto-humeral, which is the lateral cutaneous branch of the second intercostal nerve. The axillary vein separates the lesser internal cutaneous nerve from the ulnar nerve and the third portion of the axillary artery. The musculo-spiral, the largest branch of the plexus, is one of the two ter- minal branches of the posterior cord, the other terminal branch being the circum- flex nerve. It lies behind the third portion of the axillary artery and in front of the subsca pular latissimus dorsi and teres major muscles. The intercosto-humeral nerve, the lateral cutaneous branch of the second intercostal nerve, passes outward across the axilla from the inner wall to the inner side of the arm. It joins the lesser internal cutaneous nerve, pierces the deep fascia (floor of the base of the axilla), and terminates in filaments which are distributed to the skin of the inner and back part of the arm. This branch differs from the other lateral cutaneous branches of the intercostal nerves in being larger and in not dividing into an anterior and a posterior branch. It is <->_> SURGICAL AXATOMY. not uncommon to meet \vitli two intercosto-humeral nerves, in which event the second is formed l>y the posterior branch of the lateral cutaneous branch of the third intercostal. The second iiitcrcosto-huineral nerve accompanies the first in its distribution. All of the lateral cutaneous branches of the intercostal nerves emerge from the intercostal spaces midway between the vertebra' and the sternum, and, with the exception of the second, divide into an anterior and a posterior branch. The first intercostal nerve does not, as a rule, give oil' a lateral cutaneous branch. Three intercosto-humeral nerves are not infrequently seen, the third one coming from the fourth intercostal nerve. The posterior or long thoracic nerve (external respiratory nerve of Bell) is a branch of the braehial plexus given off above the clavicle, and lies along the inner wall of the axilla. It arises by three roots the upper two from the fifth and sixth, and the lower from the seventh cervical nerve. The upper two roots pierce the scalenus rnedius muscle, while the lower root passes in front of it. l/sually, the portion of the nerve formed by the union of the upper two roots and that formed by the knver root pass; into the axilla separately behind the axillary plexus and vessels, where they join to form the common trunk which supplies the serratus magnus. It lies upon the outer surface of that muscle. The axillary lymphatic glands, ten to twelve in number, most of which have been removed when clearing away the areolar and fatty tissue in exposing the contents of the arm-pit, consist of three chains an anterior, a middle, and a pos- terior. The initn-ini- cJinln lies on the serratus magnus, along the lower border of the pcctoralis minor, and in relation with the long thoracic vessels. It receives most of the lymphatics of the mammary gland, particularly those from its outer por- tion, the lymphatics of the front of the chest, as well as the superficial lymphatics of the abdominal wall as low as the umbilicus. The glands comprising this chain arc' usually the first to become enlarged in certain affections of the mammary gland, especially carcinoma. The )/(/"> may again lie called to the importance of tin- relation that the middle chain holds to the axillary vein : for when these glands are diseased, they are apt in lie adherent to this vessel and its sheath, under which circumstances the vein may he wounded and necessitate excision of a portion of the vessel. Enlarged axillary glands may press upon the axillary vein and thus produce edema of the arm. Kdema of the arm following removal of the glands and areolar tissue of the axilla may lie due to the loss of support afforded the axillary vein by these structures. The areolar and adipose tissue which occupy the axilla are considerable in amount, and fill up the intervals between the other and more important structure-. This tissue will appear more red in color and more granular and watery in character than adipose tissue elsewhere. PissKtTioN. I'pon the opposite side of the body the axilla should be dissected from below upward. Remove the skin and superficial fascia in the manner already described, when will be seen both the deep, or pectoral, and the axillary fascia. The axillary fascia may be removed in one flap or divided longitudinally and reflected laterally, the dissection being carried far enough beyond the lower borders of the folds of the axilla to expose them thoroughly. In removing the axillary fascia care should be taken to disturb as little as possible the areolar tissue of this space, which is closely connected to the upper surface of the fascia. The areolar tissue is now to be removed, exposing, first, the intercosto-humeral nerve. The other structures seen in this dissection and along the outer wall are the axillary vein and artery, the middle chain of lymphatic glands, and the axillary plexus of nerves; along the posterior wall, the long subscapular nerve, accompanying the subsea pillar artery and vein, the middle and short subscapular nerves, and the posterior chain of lymphatic glands ; along the inner wall, the long thoracic nerve ; and along the anterior wall, the long thoracic artery and vein and the anterior chain of lymphatic glands. To open a deeply-seated axillary abscess great care should be exercised. The skin and fascia should be incised, after which a grooved director is pushed forward until the outflow of pus along the groove denotes the finding of the cavity. A dressing forceps is to be introduced and forcibly withdrawn after having been partly opened. This is Hilton's method, and was suggested by him more especially for the opening of deep abscesses of the neck, so as to avoid injury to the important structures there located. The more rational method is to open the abscess by careful dissection. '.ii ; SURGICAL .-I .V.I TOMY. THE FI!(/.\T or Till-: .1/,M/. DISSKCTKIX. Continue tlie incision already made upon the outer side of the arm to a point on I lie outer side of Ilie forearm, about three inches below tin- external condvle. From the lower end of this incision make another transversely across tlie front of the forearm. Helled the skin inward as one large flap, when the superficial fascia, with its ramifying nerves and vessels, will he exposed. The Superficial Fascia. This fascia is composed of two layers a superlicial, consisting mainly of adipose tissue; and a deep layer, fibrous in structure and in direct contact with the deep fascia. Between the two layers are the superlicial nerves, vessels, and lymphatics. In the fascia upon the outer side of the arm are found the cutaneous branches of the circunillex nerve near the deltoid insertion, and helow these the external cutaneous branches of the musciilo-spiral nerve, while immediately above the elbow the musculo-cutaneous nerve becomes subcutaneous on the outer side of the tendon of the biceps. Tn addition to these nerves, the cephalic vein is seen on the outer side of the arm. In the fascia on the inner side of the arm are found the intercosto-hunicral nerve, the internal cutaneous brancb of the musculo-spiral nerve, the internal cutaneous and lesser internal cutaneous nerves, and the basilic vein. In order to trace these nerves and vessels the superficial fascia is to be removed as the skin was, being careful not to sever tlie structures which enter it from beneath. As each nerve or vessel is exposed, trace it through the superlicial fascia. The cutaneous branches of the superior division of the circumflex nerve pierce the deltoid near its insertion and are distributed to the skin over the lower part of this muscle ; the end of the inferior division of the circumflex nerve emerges from beneath the posterior edge of the deltoid, whence it ascends snbcutaneouslv to supply the skin over the long head of the triceps and the lower two-thirds of the back of the deltoid. The superior and inferior external cutaneous branches of the musculo-spiral nerve emerge through the deep fascia at about the middle of the outer side of the arm. Tlie superior branch accompanies the cephalic vein to the front of the elbow and supplies the skin of the lower half of the front of the arm. The inferior branch pierces the deep fascia below the deltoid insertion, whence it passes downward to supply the skin on the outer side of the lower half of the arm, the elbow, and the outer side of the forearm, communicating near the wrist with the posterior branch of the external or musculo-cutaneous nerve. The internal cutaneous nerve, in company with the basilic vein, pierces the deep fascia of the inner side of the arm at the junction of the middle with the lower one-third, and divides into an anterior and a posterior branch. It also gives PLATE XXV. Supra acromia! n Cutaneous branch of circumflex n.__ Intercosto-humeral n. Branch of internal cutaneous n. Lesser Internal cutaneous n._ Internal cutaneous n._ External cutaneous branch of musculo-spiral n. Mifsculo-cutaneous rt._ Palmar cutaneous branch of ulnar n._ Palmar cotaneous branch of radial n. Palmar cutaneous branch of median i Digital n Supra acromial n. Branch of circumflex n. Internal cutaneous branch of musculo-spiral n. Intercosto-humeral n. Branch of circumflex" n. Lesser internal cutaneous n. Branch of internal cutaneous n. ternal cutaneous of musculo-spiral n. Branch of musculo-cutaneous n. Radial n. Dorsal cutaneous branch of ulnar n. CUTANEOUS NERVES OF ARM AND FOREARM. 97 PLATE XXVI. Deep fascia- Branch of internal cutaneous n. Cephalic v. External cutaneous branches of musculo-spiral n Radial v: Median cephalic v. Deep median v. Musculo-cutaneous v Branch of radial n.- SUPERFICIAL VEINS OF FRONT OF ARM AND FOREARM. 100 Basilic v. Internal cutaneous n. Common ulnar v. Median basilic v. Posterior ulnar v Anterior ulnar v. Median v. PLATE XXVII. Posterior ulnar v. Communication with deep veins ~ -Deep fascia .Radial v. SUPERFICIAL VEINS OF BACK OF FOREARM AND HAND. 101 TIIT. FHOXT OF Till': ,1AM/. 103 oil' a cutaneous branch wliicli arises high up, pierces llic deep fascia at the lower border of tiie posterior fold of the axilla, ami goes to the skin of the inner side and front of the arm. The anterior branch passes downward over the elbow, cither in front of or behind the median basilic vein, to supply the skin of the front and inner side of the forearm. At the wrist it communicates with a cutaneous branch of the ulnar nerve. The posterior branch communicates with the lesser internal cutaneous nerve above the elbow, and then passes downward behind the internal condyle to supply tin- skin over the posterior and inner aspect of the forearm, and communicates with the dorsal branch of the ulnar nerve above the wrist-joint. The lesser internal cutaneous nerve (nerve of \Vrisberg) pierces the deep fascia at the middle of the arm, supplies the skin over the lower one-third of the back of the arm as well as that over the internal eondvle and olecranon, and communciates with the posterior branch of the internal cutaneous nerve. The internal cutaneous branch of the musculo-spirnl nerve is small. It arises in the axilla, and pierces the deep fascia in the upper part of the arm to supply the skin of the inner side and back of the arm almost as far as the olecranon. Superficial Arteries. The arteries which ramify in the superficial fascia of the arm are derived from above downward from the acromio-thoracic. the anterior and posterior circumflex, the superior and inferior profnnda, the muscular, and the aiiastomotica inagna. Superficial Veins. The veins found in the superficial fascia of the arm are of special interest because of their symmetric arrangement and surgical impor- tance', those in front of the elbow being especially important in venesection or blood-letting. Like veins generally, they are subject to frequent variations; but nevertheless adhere, as a rule, to the following plan : The cephalic vein is formed by the junction of the radial and median cephalic veins in the groove between the supinator longus and the lower, tapering end of the biceps muscle. It passes upward over the outer edge of the biceps muscle; and, after piercing the deej) fascia, dips into the delto-pectoral sulcus, where it is accom- panied by the descending branch of the acromio-thoracic artery. Just below the middle of the clavicle it pierces the costo-coracoid membrane and empties into the third portion of the axillary vein. The median cephalic vein is a short, venous trunk, from one and one-half to two and one-half inches in length, connecting the lower end of the cephalic vein with the upper end of the median vein of the forearm, from which it arises, in common with the median basilic, about opposite the lower end of the tendon of the biceps. It crosses the external or muscnlo-cutaneous nerve. The median basilic vein, generally shorter but of larger caliber than the Hi! SURGICAL ANATOMY. median cephalic, extends inward in front of the bicipital fascia, observing a more nearly transverse course than tin- latter vein. It joins the common nlnar vein shortly after the formation of the latter !>y the junction of the anterior and posterior nlnar veins. It generally follows the course of the sulcus Tsetween the inner edge of the lower end of the biceps and the outer edge of the pronator radii teres. It cro the hracliial artery, from which it is separated by the bicipital fascia. Brandies < f the internal cutaneous nerve pass in front of and lieliind it. This is the vein most commonly selected for intra-venons saline infusion. In venesection, or blood-letting, this is the vessel usually selected for that purpose, hecause it is the larger of the two. and therefore affords a freer ilo\v of blood. From an anatomic standpoint, however, the median cephalic 1 is the safer of the two vessels from which to bleed, on account of the more intimate relation of the median basilic vein to the brachial artery. When the practice of bleeding was so common, the thumb lancet was used in making the set-lion of the vein. As the blade of this instrument was at a right angle to the handle and was driven by a spring, it can be readily understood why the artery was endangered if the lancet was not held at the proper height. To obviate the risk of injuring the brachial artery, the vein should be exposed by dissection and cut obliquely in prefeience to transversely to preclude the danger of completely dividing the vessel. The open- ing in the skin should be larger than that in the vein, so that blood will not escape into the cellular tissue and form a thrombus. If the blood does not flow freely when the vein is opened, the patient should move his fingers while grasping something in his hand ; this favors compression of the deep veins and causes -the blood to flow into the superficial veins through the mediana profunda and the remaining veins that connect the superficial and deep veins. The basilic vein, which is much larger than the cephalic, is formed by the junction of the common ulnar and median basilic veins, and passes upward in front of the inner margin of the biceps to pierce the deep fascia at the junction of the lower with the middle one-third of the arm. It passes upward along the inner side of the brachial artery to become the axillary vein at the lower border of the tendon of the teres major. Lymphatics. Lymphatic glands are generally found at the elbow, some- times two or three in front and one or two near the lower end of the basilic vein and internal eondyle. Special interest centers in them because they become swollen and inflamed in poisoned wounds of the hand. The gland in front of and above the internal eondyle, known as the epitroch- lear, is often found enlarged in early syphilis. It is usually single, but sometimes two, or even three, glands are found in this location. The superficial lymphatics, beginning below the elbow and formed by the PLATE XXVIII. SUPERFICIAL LYMPHATIC VESSELS AND GLANDS OF FRONT OF UPPER EXTREMITY. 105 THE Fi;<)\T Oh' Till-: Aim. 107 junction of the lymphatics from the outer and inner side of the front of the forearm, pass along the inner side of the arm \vith the basilic vein to enter the axillary glands. A few of those on the outer side of the forearm pass up the outer side of the arm with the cephalic vein and. crossing the biceps in its upper part, join the axillary glands, though one or two lymphatic vessels usually con- tinue with the cephalic vein through the delto-pectoral sulens to enter the suhclaviau glands. The dee]> lymphatics follow the course of the arteries. One or more lymph-glands are occasionally found in the delto-pectoral sulcus. Reflect the superficial fascia in the same manner in which the skin was reflected. In removing this fascia the superficial veins and nerves are to be traced. It is more convenient to follow these structures through the under surface of the fascia. Deep fascia. The removal of the superficial fascia exposes the dee]) fascia, which is fibrous in structure. It is continuous with its adjacent counterparts of the shoulder, back, chest, and forearm. It is attached above to the anterior edge of the clavicle and to the outer and inferior edges of the acromion process and spine of the scapula. Passing downward, it envelops the muscles and other deep structures of the arm and is attached, below the tendon of the triceps muscle, to the bony prominences of the elbow-joint, the olecranon and condyles, whence it continues downward as the general investiture of the forearm. In addition to enveloping the muscles by means of processes constituting sheaths, it forms parti- tions between them. Two of these, one on either side of the arm, are known as the internal and external intermuscular septa, It varies in thickness, being thickest over the triceps and the condyles of the humerus, thinnest in front of the biceps, and intermediate in thickness upon the inner side of the arm, where it serves to cover and protect the main vessels and nerves. Internally, it is rein- forced by accessory fibers from the tendons of the pectoralis major and latissimus dorsi, and externally by fibers from the tendon of the deltoid. The intermuscular septa. The internal intermuscular septum is attached to the internal eondyloid ridge, and extends from the insertion of the coraco- hrachialis to the internal condyle of the humerus. It blends with the tendon of the coraco-brachialis, and gives attachment to the triceps behind and the brachialis anticus and pronator radii teres in front. In the middle of the arm it is perforated by the ulnar nerve and inferior profunda artery, and below by the anastomotica magna artery. The external intermuscular septum is attached to the external condyloid ridge, and extends from the insertion of the deltoid to the external condyle of the humerus. It blends with the tendon of the deltoid and gives attachment to the triceps behind, and to the brachialis anticus, supinator longus, and extensor carpi radialis longior in front. It is per- 10S SURGICAL ANATOMY. forated below the middle of the unn by the musculo-spiral nerve and tlic superior profunda artery. These intermuscular septa, with tin 1 lion.', divide the lower half of the arm into i\\" osteo-fascial compartments an anterior and a posterior. In the anterior compartment are found the biceps, the brachiahs anticus, and the origins of the supinator longus and extensor carpi radialis lougior, tlie brachial vessels, the basilic vein, the anastomotica magnu, the inferior profunda and the termination of the superior profunda, the radial recurrent and anterior ulnar recurrent arteries, the median, ulnar, internal cutaneous, and musculo-cutaneous nerves, and the lower part of the musculo-spiral nerve. In the posterior compartment are the triceps muscle, the musculo-spiral nerve, the superior profunda artery, the ulnar nerve, the inferior profunda artery, and the anastomotica magna artery. DISSECTION. Divide the deep fascia in the median line of the front of the arm and reflect it laterally, exposing to view those structures which lie in the ante- rior part of the arm. In rellecting the fascia from the inner side of the arm it is best to sever the internal intermuscular septum, taking care, however, not to injure the structures that pierce it. This will expose, in front, the biceps; on the inner side, the coraco-brachialis, the brachialis anticus. and the triceps; on the outer side, the deltoid, brachialis anticus, and the origins of the supinator longus and extensor carpi radialis longior. The sulcus upon the inner side of tlie arm, between the biceps in front and the triceps and brachialis anticus behind, is occupied by the principal vessels and nerves. Before proceeding fur- ther with the dissection the student should carefully examine the relation of the brachial vessels to the coraco-brachialis and biceps muscles, and the median nerve which accompanies the vessels, as the relations of these structures are somewhat altered by cleaning. The brachial artery, the continuation of the axillary, begins opposite the lower border of the tendon of the teres major. It passes down the inner side of the arm, overlapped for fully two-thirds of its course by the inner border of the coraco-brachialis and biceps muscles. It then curves inward in front of the elbow- joint, along the inner border of the tendon of the biceps, opposite the insertion of which, one-half to one inch below the elbow-joint, it divides into the radial and ulnar arteries. Its course is quite accurately indicated by a line drawn from the junction of the anterior and middle third of the outer wall of the axilla, to the middle of the front of the elbow-joint. It should be remembered that the hrachial artery quite frequently bifurcates some distance above the usual point, the two vessels then running side by side. RELATIONS OF THE BKACIIIAL AKTKRY. From above downward, upon its outer side', are the coraco-brachialis and the biceps, which slightly overlap the artery. PLATE XXIX. Deltoid m. Cephalic v. Pectoralls major m. Coraco-brachialis m - Short head of biceps m. Brachia! a. Long head of biceps m. Median n. Basilic v Median basilic v Supinator longus m. Bicipital fascia- Biceps tendon Radial a Lesser internal cutaneous n Dinar n. -Teres major m. Basilic v. Long head of triceps m. Musculo-spiral n. Superior profunda a. Internal cutaneous n. Ulnar n. Inferior profunda a. Lesser internal cutaneous n. inner head of triceps m Anastomotica magna a. Internal intermuscular septum Posterior ulnar v. Pronator radii teres m. Anterior ulnar v. Flexor carpi radialis m. Palmaris longus m Flexor carpi ulnaris m BRACHIAL ARTERY AND BICEPS MUSCLE. 110 PLATE XXX. Anterior circumflex a. Posterior circumflex a. Muscular branch Radial recurrent a. Posterior interosseous recurrent a. Radial a. Axillary a. Subscapular a, Dorsalis scapulae a. Superior profunda a. Inferior profunda a. Brachial a. Nutrient a. Anastomotica magna a. Anterior ulnar recurrent a. Posterior ulnar recurrent a. Ulnar a. BRACHIAL ARTERY AND BRANCHES. Ill THE /7,'o.V/' OF Till-: ARM. 113 \Vlini the biceps arises by three heads, tin.- artery, at its upper portion, lies beneath tin.' innermost head. The median nerve, for about one inch, also lies on its outer side in the groove between the artery and the coraco-brachialis. In front of the artery are the skin and fascia-, the inner borders of the coraco-brachialis and biceps in the upper two-thirds of its course, the median nerve in the middle third, and the bieipital fascia and median basilic vein below; on the inner side are the ulnar nerve in tlie upper half of its course, the internal cutaneous nerve and basilic vein in the upper two-thirds of its course, and the median nerve in the lower third ; behind are the musculo-spiral nerve and superior profunda artery, the long and inner heads of the triceps in the upper part of the arm, the insertions of the coraco- brachialis in the middle, and the braehialis anticus in the lower part of the arm. Throughout its course it is flanked by two closely adjacent accompanying veins (vena 1 coinites). connected with each other by occasional transverse veins. The artery is comparatively superficial throughout its entire extent, being covered by skin and superficial and deep fascia, except in the middle of its course, where the median nerve lies in front, and at its lower end, where the bieipital fascia and median basilic vein are in front of it. It is most readily compressed in the middle of the arm, where it rests upon the insertion of the coraco-brachialis. The pressure should be directed outward and backward. This is the most suitable point for compressing the artery with the pad of the tourniquet in amputation of the forearm or lower arm. The branches of the brachial artery are the superior and the inferior profunda, nutrient, anastomotica magna, muscular, and occasionally vasa aberrantia. The superior profunda artery, the largest branch, arises from the inner and back part of the upper end of the brachial, and, turning backward, it enters the musculo-spiral groove with the musculo-spiral nerve. In the groove it passes behind the humerus, between the inner and outer heads of the triceps, to the outer side of the arm, pierces the external intermuscular septum, and continues downward between the braehialis anticus and supinator longus muscles to the elbow, where it anastomoses with the radial recurrent. In its course it sends branches to supply the deltoid, coraco-brachialis, and triceps muscles, and a branch to anastomose with the circumflex arteries. It gives off a large posterior i-(iiic/i<-n arise from the outer side of the brachial artery and supply the coraco-brachialis, biceps, and brachialis anticus muscles. Vasa aberrantia are long, narrow arteries which are occasionally found con- necting the brachial or axillary artery with some of the main arteries of the fore- arm, usually the radial. The vasa aberrantia, together with the liberal anastomosis around the elbow- joint, are very important, as they offer channels for collateral circulation of t he- blood when its flow through the radial, ulnar, or lower part of the brachial arteries is prevented by compression, ligation, or trauma. The Muscles in Front of the Arm are the biceps, the coraco-brachialis, and the brachialis anticus. The biceps is the largest and most prominent muscle of this group. It arises by two heads the long and the short. The lour/ law! arises by a tendon from the upper border of the glenoid cavity of the scapula, being continuous with the glenoid ligament, by means of which it is united with the long head of the triceps, which in turn arises from the lower border of the same cavity. The tendon of the long head passes through a sheath derived from the synovial sac of the shoulder-joint, in which it arches over the head of the humerus. It PLATE XXXI. Coraco-acromial ligament Deltoid m.(cut) Long head of biceps m Tendon of oectoralls major m.(cut) Brachialis antlcus m. Musculo-cutaneous n Supinator longus m. Brachial a. Coracoid process Coraco-brachialis m. Musculo-cutaneous n. Short head of biceps m, Median n. Basilic v. Long head of triceps m. Inner head of triceps m Ulnar n. Inferior profunda a. Brachialis anticus m. Anastomotica magna a Bicipital fascia Biceps tendon BICEPS MUSCLE. 115 PLATE XXXII, Coraco-acromial ligament Deltuid m Long head of biceps m. Pectoralis major tendon Brachialis anticus m Supinator longus m Biceps tendon Pectoralis minor tendon Short head of biceps m. Anterior circumflex a. Coraco-brachialis m. Brachial a. Musculo-cutaneous n. Basilic v. .Long head of triceps m. Ulnar n. Inferior profunda a. Inner head of triceps m. Anastomotica magna a. Median n. Pronator radii teres m. Flexor carpi radialis m. Flexor carpi ulnaris m. VIEW OF ARM, -BICEPS REMOVED. 118 THE FI,'0.\T OF THE AHM. II!) emerges from the capsule, where the latt.T unites with the hunicrus. It passes down the bicipital groove, in wliich it is retained by an aponeurosis derived t'nun tlie tendon of the pectoralis major. Its synovial slieatli covers it in the upper two inches of the groove. This liead becomes muscular shortly after leaving the groove. The xln.n-t lu-u of the coraenid process of the scapula hy a flattened tendon in common with the coraco-hrachialis, whence it passes downward and a little outward to join the long head opposite the middle of the humerus. The biceps ends below in a flattened tendon, which, after giving oft' an aponeurotie expansion (bicipital aponeiirosis) from its inner side, becomes twisted upon itself, and is inserted into the posterior edge of the tuberosity of the radius. A synovial sac intervenes between (he tendon and the anterior part of the tuberosity. The bicipital aponeurosis passes inward over the braehial artery and beneath the median basilic vein and blends with the deep fascia of the forearm. Interest attaches to the relation of the braehial artery to the bicipital aponeurosis and the median basilic vein, because, inexplicable as such an accident may seem. it has happened that the artery, as we'll as the vein, has been opened in venesection, an arterio-venous aneurysm resulting. The two bellies of this muscle are united by connective tissue almost as far as the tendon, near which their fibers interdigitate before attachment to the front of this structure. The biceps, in its upper part, rests upon the imisculo-cutaneous nerve, which passes obliquely behind it, and against the humerus ; in its lower half it lies upon the brachialis anticus. Its tendon occupies the triangular space in front of the elbow, the braehial artery being on its inner side. On the inner side of the muscle are the coraco-brachialis muscle, the braehial vessels, and the median nerve. Its upper end is covered by the tendon of the pectoralis major and the anterior edge of the deltoid. For the remainder of its course it is subcutaneous and readily discernible. Occasionally, between the coraco-brachialis and brachialis anticus, there arises from the inner side of the humerus an accessory head, which, in its course toward the bicipital fascia for insertion, assumes varying relations with the braehial artery, either crossing in front of or behind the artery, or dividing to permit this vessel to pass through it. In ligating the braehial artery an accessory muscular head, when present, may be severed without hesitation. ACTION. Its function is to flex the forearm on the arm, to supinate the forearm, and to slightly adduct the arm. It is also well to bear in mind that in no part of its course is the biceps muscle normally attached to any part of the humerus, though bearing the most intimate relation to this bone anatomically and functionally. BLOOD SUPPLY. From the muscular branches of the braehial artery. NERVE SUPPLY. From the musculo-cutaneous nerve. l^o SURGICAL ANATOMY. The coraco-brachialis muscle, arising conjointly with the short head of the biceps, extends t'roin tlie tip of the eomeoid process to the middle of the inner side of the humerus, where it is inserted into a rough impression between the attach- ment of the inner head of the triceps and the brachialis anticus. and opposite the insertion of the deltoid. It is perforated obliquely, from within outward, by the musculo-cutaneoua nerve, from which it derives jt^ nerve supply. Aboyi , it is hidden by the pectoralis major and deltoid; it then becomes, superficial as far as its insertion, where it is crossed by the bradiial vessels and median nerve. Behind, this muscle is in contact with the tendons of the snbscapnlaris. teres major, and latissimns dorsi, and the short head of the triceps muscle, the humerus, and the anterior circumflex vessels. Internally, it is in relation with the pectoralis minor, the third part of the axillary artery, the brachial vessels, and the median and musculo-cntaneous nerves. Externally, it lies in contact with the short head of the biceps. It derives its nutriment chiefly from the .brachial artery. ACTION*. Its function is to draw the arm forward and inward. The brachialis anticus muscle arises from the humerus by two fleshy digita- tions on either side of the in-crtion of the deltoid, and from the front and inner side of the; shaft of the bone below this point, as well as from the external and internal intcrnmscnlar septa. It is a broad, flat muscle, which covers the lower half of the front of the humerus and the anterior ligament of the elbow-joint, to which it is closely attached. It ends in a short tendon, which is inserted into the front of the base of the coronoid process of the ulna, where it bears the same relation to the two (limitations of the flexor profnndns digitorum that the inser- tion of the deltoid does to it above. This muscle is covered by the deep fascia on the outer side and by the biceps, and is crossed by the brachial vessels, the median, the musculo-cutaneous, and mnscnlo-spiral nerves. Externally, it is related with the musculo-spiral nerve, the superior proi'nnda and radial recurrent arteries, the long radio-carpal extensor and long snpinator muscles; while internally it is in contact with the triceps, ulnar nerve, and pronator radii teres. BLOOD SUPPLY. From the brachial artery. NERVE SUPPLY. From the musculo-cutaneous and the musculo-spiral nerves. ACTION. To flex the forearm on the arm. The Nerves of the Arm proceed from the axillary or brachial plexus. They are the musculo-cutaneous, from the outer cord ; the median, from the inner and outer cords ; the ulnar, internal cutaneous, and lesser internal cutaneous, from the inner cord; and the circumflex and musculo-spiral, from the posterior cord. The ramifications of these in the superficial fascia have been fully described, while the course of the main trunks has been casually mentioned: Of the larger nerves, the median and ulnar pass down the inner side of the arm ; the circumflex and PLATE XXXIII. LINES OF ARTERIES OF UPPER EXTREMITY AND OF MEDIAN AND ULNAR NERVES. 122 THE FRONT OF THE ARM. 123 musculo-spiral curve behind tlie humerus to the outer side of the arm ; the nmsculo- cutancous crosses the front of the arm to the outer side of the forearm. Of these, the circumflex is the only one which has ascending brandies. The musculo-cutaneous nerve, arising from the outer cord of the axillary or brachial plexus, opposite the lower margin of the pectomlis minor, at once enters the coraco-brachial muscle, through which it, passes downward and outward, thence between the biceps and brachialis anticus to the outer side of the arm a little above the elbow, where it pierces the deep fascia. It supplies the coraeo-braehialis, biceps, and brachialis anticus muscles, the humeras, and the elbow-joint. At the elbow it passes beneath the median cephalic vein and divides into an anterior and a posterior branch. The anterior branch communicates with the radial nerve and ends in the skin over the thenar eminence ; the posterior branch supplies the skin as far as the wrist. Loss of the power of elbow flexion, associated with numb- ness or anesthesia of the outer side of the forearm, would indicate an affection of this nerve. The median nerve is formed by two fasciculi, or nerve strands, one from the outer and the other from the inner cord of the axillary plexus ; they unite like the arms of the letter Y and are known as the outer and the inner heads, the stem formed by their union being the median nerve. The two heads lie on opposite sides of the lower or third portion of the axillary artery and unite either in front of it or on its outer side. In its course along the inner side of the arm it hugs the brachial artery, being generally upon the outer side of this vessel in its upper part, then gradually moving inward to rest in front of it in the middle of the arm, and continuing inward so that it lies upon the inner side of this vessel in the lower third of the arm. At the lower end of the arm it is covered by the bicipital aponeurosis or fascia, and is crossed by the median basilic vein. It gives off mus- cular branches and the anterior interosseous nerve, and continues downward to the palm. In the middle of the arm the median nerve is occasionally found behind the brachial artery, instead of in front. The ulnar nerve arises, in common with the inner head of the median nerve, from the inner cord of the axillary plexus. It passes downward along the inner side of the axillary and brachial arteries, diverging inward from the latter at the middle of the arm opposite the insertion of the coraco-brachialis muscle. It then crosses the inner head of the triceps and, in company with the inferior profunda artery, pierces the internal intermuscular septum to enter the groove between the olecranon and internal condyle. Special interest attaches to the position of the ulnar nerve in the sulcus between the internal condyle and the olecranon, on account of its liability to injury there. Trauma of the nerve in this position is frequent. It is followed by a tingling sensation, felt at its distribution to the little 1-24 SURGICAL AXATOMY. and ring fingers, whence is derived the name "cra/y bone" or " funny bone." The ulnar nerve holds so close a relation to the posterior surface of the internal condyle that, in trad lire of the condyle, a fragment or callus may press upon the nerve and produce tingling or numbness of the ulnar side of the forearm and hand, little finger, and ulnar side of the ring linger, and spasm or paralysis of the muscles supplied by this nerve. These muscles are the flexor carpi ulnaris, ulnar side of the flexor profundus digitorum, palmaris brevis, muscles of the hypothenar eminence, interossei, two ulnar lumbricales, adductor pollicis, and inner head of the flexor brevis pollicis. The internal cutaneous nerve arises from the inner cord of the axillary plexus, passes down ward along the inner side of the axillary and brachial arteries, between the latter and the ulnar nerve, and divides a little below the middle of the arm into an anterior and a posterior branch. The anterior branch enters the forearm either in front of, or behind, the median basilic vein ; the posterior branch descends along the inner side of the basilic vein to enter the forearm behind the internal condyle. Before it divides, it gives off a cutaneous branch, which pierces the deep fascia and supplies the skin of the anterior and inner side of the arm almost as far as the elbow. The lesser internal cutaneous nerve (nerve of Wrisberg) arises from the inner cord of the axillary plexus above the origin of the internal cutaneous nerve, from which point it passes behind the axillary vein, and then on the inner side of the vein, where it communicates with the lateral cutaneous branch of the second inter- costal nerve (the intcrcosto-humeral). It then passes downward to the middle of the arm, where it pierces the deep fascia, and is distributed to the skin over the lower part of the back of the arm, the inner condyle, and the olecranon. The circumflex nerve arises, with the musculo-spiral, from the posterior cord of the axillary plexus. It descends in front of the subscapularis muscle behind the axillary artery, and turns backward at the lower margin of the muscle, giving off an articular branch which enters the shoulder-joint below the subscapularis. It divides into an upper and a lower branch. The upper branch, in company with the posterior circumflex vessels, curves behind the surgical neck of the hunicrus and under the deltoid to its anterior border, giving off filaments in its course to supply the muscle and the skin covering it. The lower branch sends to the teres minor muscle a filament, usually containing a gangliform enlargement, and one or more branches to the back part of the deltoid ; it then pierces the deep fascia to supply the skin over the long head of the triceps and the lower two-thirds of the back part of the deltoid. Injury to this nerve would cause tingling or partial anesthesia, and muscular twitching or paralysis of the deltoid and teres minor. The musculo-spiral nerve is the continuation of the posterior cord, and /'///: /7,'o.vv a i-' '!'!/!: /-'o ///;. i /.M/. .i^r, is tlif largot 1. ranch of the axillary plexus. It passes downward behind tin- axillary vessels and in front of Ilie tendons of tiie lalissiiuus dorsi and tcres niiijur. Accompanied by the superior profunda artery, it then pa>ses down- ward and outward between the outer and inner heads of the triceps around the back of the humerus in the nmsculo-spiral groove to the outer side of the lower part of the arm, where ii pierces the external interniuscular septum. Thence it continues downward between the brachialis anticus, internally, and the supinator longus, externally, to the front of the outer coiulyle, where it divides into the radial and posterior interosseous nerves. On the inner side of the arm it gives off lull rmil niiixriiliii' In'iiiii'licx to the outer and inner heads of the triceps; in the miisculo-spiral groove it sends branches to the outer head of the triceps and the ancmieus; on the outer side of the arm it gives off external branches to the snpinator longus, extensor carpi radialis longior, and brachialis anticus. A small inti 1-inil cutaneous In-mirli arises in the axilla, and passes to the skin of the inner side and back of the arm almost as far as the olecranon. A superior external cuta- neous In-iiiK'li perforates the external head of the triceps close to the humerus, then pierces the deep fascia and accompanies the cephalic vein to the front of the elbow, supplying the skin of the lower half of the front of the arm. An inferior c.iicnial cutaneous I>nnn-Ii also goes through the outer head of the triceps with the preceding branch, then pierces the deep fascia near the insertion of the deltoid, and pa--e- downward to be distributed to the skin on the outer side of the lower half of the arm, the elbow, and the outer back part of the forearm, communicating near its termination with the posterior branch of the musculo-cutaneous or external cuta- neous nerve. As the musculo-spiral nerve lies in contact with the back of the shaft of the humerus, paralysis of this nerve is a complication of fracture of that bone. Paralysis of this nerve either from fracture of the humerus, pressure of a crutch, lead poisoning, or over-stretching of the nerve, as from lifting a child by the arm, results in " wrist drop " and pronation of the forearm. THE FRONT OF THE FOREARM. DISSECTION. Extend the forearm and hand so as to make tense the structures in this region. Continue the incision made along the outer side of the arm down the radial side of the forearm to the tip of the styloid process of the radius. From the latter point carry a transverse incision across the front of the wrist. Reflect the skin from without inward, when the superficial fascia and the superficial veins AXATOMY. will l>e exposed. The skin is thin, can lie raised in folds, and allows the super- ficial veins to lie seen lii'iieath it. In the superficial fascia are found the radial, anterior ulnar, and median veins, and the niusculo-eutaneous or external cutaneous nerve, the internal cuta- neous nerve, cutaneous brandies of the ulnar and median nerves, branches of the radial and ulnar arteries, and the superficial lymphatics. The radial vein appears upon the front of the radial side of the forearm above its lower third, where it winds from behind forward and upward on the radial side of the forearm (generally superficial to the external cutaneous nerve) to form the cephalic vein at the elbow by junction with the median cephalic. It arises from the radial side of the dorsal venous arch of the hand, receives radicles from the back of the thumb and index finger, and communicates with the median vein. The anterior ulnar vein passes upward along the ulnar side of the forearm to within a short distance of the elbow, where it joins the posterior ulnar to form the common ulnar, which in turn almost immediately unites with the median basilic to form the basilic vein. It is formed by radicles at the wrist, and communicates with the median and posterior ulnar veins. The median vein begins at, or a little above, the wrist and runs up the middle of the forearm. It collects blood from the palm of the hand and the front of the forearm, and communicates freely with the radial and anterior ulnar veins. Upon reaching the bend of the elbow, it communicates with the vena? comites of the radial artery by means of the deep median vein and at once divides into two branches the median cephalic and median basilic. The musculo-cutaneous or external cutaneous nerve becomes superficial a short distance above the elbow on the outer side of the tendon of the biceps, and passes downward upon the outer side of the front of the forearm, ending upon the ball of the thumb (thenar eminence). It gives off, just below the elbow, a posterior branch which supplies the outer side of the back of the forearm. The anterior branch the continuation of the musculo-cutaneous lies in front of the radial artery in the lower part of the forearm and communicates with a branch of the radial nerve. It terminates in filaments to the skin over the ball of the thumb. The anterior branch of the internal cutaneous nerve enters the forearm at the inner side of the front of the elbow, either in front of, or behind, the median basilic vein ; thence it continues downward upon the ulnar side of the front of the forearm, supplying the skin on its way to the wrist, where it communicates with a branch of the ulnar nerve. A cutaneous branch of the ulnar nerve is found coming through the deep fas- cia about a hand's breadth above the wrist near the tendon of the flexor carpi ulnaris. PLATE XXXIV. Biceps m.- Cephalic v.- Supinator longus m. Radial v.- Median cephalic v. Extensor carpi radialis longio Musculo-cutaneous n.- Biceps tendon Vena comites of radial a: Deep median v. Radial a. Median v. Ulnar n. Inferior profunds a. Inner head of triceps m. Basilic v. Anastomotica magna a. Brachiaiis anticus m. Median n. Brachial a. Internal cutaneous n. Posterior ulnar v. Anterior ulnar v. Pronator radii te^es m. Median basilic v. Bicipital fascia Palmaris longus m. Flexor carpi ulnaris m. Pronator radii teres m. BICIPITAL FASCIA AND VESSELS AND NERVES AT ELBOW. 128 THE FROA'T OF THE FOREARM. 129 A cutaneous branch of the median nerve pierces the deep fascia about two inches above the middle of the wrist and pusses to the palm. The superficial arteries of the forearm are small cutaneous branches from the radial and ulnar arteries. The superficial lymphatics accompany the superficial veins, and are more numerous upon the ulnar than upon the radial side of the forearm. They com- mence at the ends of the fingers two on the palmar and two on the dorsal surface. Those on the palmar surface of the fingers join an arch in the palm of the hand, from which arise the vessels which accompany the anterior ulnar, the median, and radial veins ; those on the dorsal aspect of the fingers form a plexus on the back of the hand, from which vessels pass up the back of the forearm and around either side to empty into those on the anterior surface of the forearm. The greater number of these vessels pass upward on the inner side of the arm with the basilic vein. A few accompany the cephalic vein. DISSECTION. Trace the superficial veins in the superficial layer of the super- ficial fascia and remove this fascia in one flap like that of the skin. Follow the nerves through the under surface of the fascia. The deep fascia is now exposed. The deep fascia of the forearm is continuous with that of the arm, and com- posed of circular and oblique white fibers bound together by a few longitudinal fibers. It is attached to the bony prominences of the forearm, and sends prolonga- tions between the muscles, separating them and affording additional surfaces for their origin. It is most dense at the back of the forearm, least so in front of the upper part of the forearm, and intermediate in thickness above and at the wrist. In the last-named location it forms the posterior annular ligament and is continuous with the anterior annular ligament. It is reinforced by tendinous accessions from the biceps (bicipital aponeurosis), brachialis anticus, and triceps. Its numerous intermuscular septa at the elbow, beginning at the limited area of the surface of the internal condyle and expanding, form cone-shaped aponeurotic cavities for the origins of many muscles. A transverse intermuscular septum divides the muscles of the forearm into a superficial and a deep group. Besides smaller apertures for the passage of cutaneous vessels and nerves, it contains an aperture of considerable size below the elbow for the passage of the deep median vein, which connects the vense comites of the radial artery with the superficial veins. DISSECTION. Remove the deep fascia by incisions corresponding to those used in reflecting the skin and superficial fascia. The removal of the deep fascia at the upper and inner part of the forearm can not be accomplished so satisfactorily as in most other regions, owing to its blending with the . underlying superficial group of flexor muscles, to which it gives partial origin. It can be removed to !:-!<> SURGICAL AXATo.MV. better advantage by reflecting it from below upward. A similai 1 dilliculty is encountered at the buttock in the removal of the dee]> fascia from the great gluteal muscle, the main difference between the two fascia: being that, in the gluteal region the deep fascia sends septa into the muscle itself, while in the forearm the septa pass between the muscles. The triangle at the bend of the elbow. Upon the removal of the deep fascia, a triangle is exposed ;it the bend of the elhnw. This triangle is hounded above 1 by an imaginary line which is drawn between the condyles of the Immerus and forms the base : externally, by the snpinator longus : and internally, by the pronator radii teres. The apex of the triangle is at the point where the supinator longus crosses the pronator radii teres. The floor is formed by the braehialis anticus and supinator brevis muscles, and the deep fascia forms its roof. Within this triangle, when its lateral boundaries are displaced, the supinator longus outward and pronator radii teres inward, the following structures are seen from within outward : The anterior ulnar recurrent artery, the median nerve, the brachial artery, its vena 1 comites, the two terminal branches of the brachial or the radial and ulnar arteries, their vena 1 comites, the deep median vein, Un- common interosseous artery, the tendon of the biceps, the radial recurrent artery, and the musculo-spiral nerve. In rupture of the biceps muscle the tendon can be distinctly felt loose and free and can be manipulated in tin's space. The effusion of blood renders approximation impracticable without operative interference. The Muscles of the forearm may be divided into groups : an inner or anterior, and an outer or posterior; the former including the pronators and flexors ; the latter, the supinators and extensors. The inner group chiefly arises by a common tendon from the internal condyle and internal condyloid ridge, and the outer, from the external condyle and the external condyloid ridge. The pronator radii teres, the shortest muscle of this group, arises by two heads a large or superficial, and a small or deep. The large or superficial head springs from the anterior surface of the humerus above the internal condyle, an intermuscular septum separating it from the flexor carpi radialis and the deep fascia of the forearm; the small or deep head arises as a narrow bundle of fibers from the inner aspect of the coronoid process of the ulna. The two heads unite at an acute angle, and between them passes the median nerve to the deeper part of the forearm. The muscle then extends obliquely downward and outward, and is attached by a flat tendon to the middle of the outer surface of the shaft of the radius. The tendon is overlapped by the supinator longus. The muscle is sub- cutaneous, except near and at its insertion, where it is covered by the supinator longus and crossed by the radial vessels and nerve. The radial border of the muscle forms the inner boundary of the triangle at the bend of the elbow, while PLATE XXXV, Musculo-cutaneous n._ Biceps tendon Radial recurrent a. Radial a Supinator longus m. Extensor carpi radialis longior m Radial a Radial n. Extensor ossis metacarpi pollicis tendon Extensor primi intern odii pollicis tendon Superficialis volae a. Branch of anastomotica magna a. Median n. Brachialis anticus m. Brachial a. Bicipital fascia Pronator radii teres m. Ulnar a. Flexor carpi ulnaris m. Palmaris longus m. Flexor carpi radialis m. Flexor sublimis digitorum m. Median n. Ulnar a. Ulnar n. TRIANGLE OF ELBOW AND SUPERFICIAL MUSCLES OF FOREARM, 131 '/'///: n;n\T <>\' nil-: I-'URKMIM. 133 the ulnar border is in relation with the Hcxor c;ir|>i radialis. Its under surface is in contact with the brachialis anticus and flexor sublimis digitorum muscles, the median nerve, and ulnar vessels. The inner head of the muscle separates the median nerve in front from the ulnar vessels behind. BLOOD SUPPLY. Its nutriment is derived from the radial, ulnar, and anasto- motiea magna arteries. NF.KVK SUPPLY. From the median nerve-. ACTION. I'ronates and flexes the forearm. The flexor carpi radialis arises by the common tendon from the internal condyle, also from the deep fascia and contiguous surfaces of the adjacent inter- muscular septa. It passes down the forearm to the radial side of the front of the wrist, where it traverses a canal in the anterior annular ligament and a groove upon the trapezium, and is ultimately attached to the anterior surface of the base of the metacarpal bone of the index finger. A small slip passes to the base <>! the metacarpal bone of the middle ringer. The groove in the trapezium is con- verted into a canal by a fibrous sheath, the canal being lined by a synovia! mem- brane. This muscle is tendinous in its lower three-fifths; its belly is full and fusiform. It is superficial, with the exception of the small portion of the tendon which enters the annular ligament ; it lies upon the flexor sublimis digitorum, the flexor longus pollicis, and the wrist-joint. Externally, it is in contact with the pronator radii teres, and in its lower half is very near the radial vessels ; internally, it lies against the palmaris longus muscle, above. Above the wrist the median nerve is on the inner side of its tendon. BLOOD SUPPLY. Its nutriment is derived from the radial artery and ulnar recurrent artery. NERVE SUPPLY. Derived from the median nerve. ACTION. Its main function is to flex the wrist ; it also aids in flexion of the elbow, and with the hand supinated it aids in pronation. The palmaris longus, often absent, is slender and spindle-shaped. It arises by the common tendon from the inner condyle, also from the deep fascia and the adjacent intermuscular septa. Its slender tendon passes over the anterior annular ligament to terminate in an expanded prolongation, which is continuous with the central portion of the palmar fascia, the deep fascia over the thenar eminence, and the anterior annular ligament at the base of that eminence. It is sub- cutaneous, except at its origin, where it is partly overlapped by the flexor carpi radialis. It lies upon the flexor sublimis digitorum, the median nerve, and the anterior ligament, and is in relation with the flexor carpi ulnaris internally, and with the flexor carpi radialis externally. BLOOD SUPPLY. From the ulnar artery. i:U SniK'M< ANATOMY. XKIIVK Srpri.Y. From the median nerve. ACTION. It makes tense the palmar fascia. Ilexes (lie wrist, and aids slightly in elbow flexion. Tile flexor carpi ulnaris, a long and flat muscle, embraces the outer side of the upper part of the shaft of the ulna. It arises l>y two heads one by the com- mon tendon from the internal condyle, the other from the inner aspect of the oleeranon process and partly l>y an aponeurosis continiUMl down from the upper poll ion of the posterior border of the ulna. Fibers also arise from the overlying deep fascia and the intermuscular septum between this muscle and the llexor sub- limis digitorum. The interval between the condyloid and oleeranon heads is spanned by a tendinous arch, under which pass the ulnar nerve and the posterior ulnar recurrent artery. The muscle terminates in a tendon which runs along its anterior margin, the lower fibers passing to the tendon obliquely downward and forward. It is inserted into the pisiform bone, with more or less fibrous connec- tion with the anterior annular ligament, the unciforin bone, and the base of the metacarpal bone of the little finger. It is the only muscle of the forearm attached to carpal bones. Its anterior and inner surfaces are subcutaneous, and intimately attached to the deep fascia over much of their extent, especially near the posterior border of the ulna. It lies upon the flexor sublimis digitorum and flexor pro- randus digitorum muscles, and the ulnar vessels and nerve. Its tendon is the guide for ligation of the ulnar artery, which it overlaps. Externally, it is in contact with the belly of the palmaris longus muscle and the ulnar vessels and nerve. lii.ooi) Sri'i'i.v. From the ulnar artery. NKKVK STITLV. From the ulnar nerve. ACTION. It flexes and add tic ts the hand, and slightly flexes the forearm on the arm. Owing to its extensive connection with the ulna, this muscle can not retract so much as the other muscles of this group in amputation of the forearm. The flexor sublimis digitorum (perforatus) lies under the previously described muscles and arises by three heads one from the humerus, ulna, and radius, respectively. The humeral head arises from the inner condyle by the common tendon of the flexor muscles, from the internal lateral ligament of the elbow-joint, and the adjacent intermuscular septa ; the ulnar head arises from the inner side of the coronoid process of the ulna, just above the origin of the lesser head of the pronator radii teres; the radial head arises from the oblique line of the radius and the anterior surface of that bone to a point below the insertion of the pronator radii teres. The fibers pass, directly downward from the three origins as a broad, thick, and fleshy mass, converging at about the middle of the forearm into four tendons, PLATE XXXVI, Muscuio-splral nr Brachialis anticus m. Posterior interosseous n.- Radial n. Radial recurrent a.- Supinator brevis m Radial a. Extensor carpi radialis longior m Supinator longus m Extensor carpi radialis brevior m Radial n Flexor longus pollicis m Pronator quadratus m. Anterior carpal a.- Flexor carpi radialis tendon Palmaris longus tendon Superficialis volae a.- Brachialis anticus m. Loop between anastomotica magnaa. and anterior ulnar recurrent a. Median n. Bicipital fascia(cut) Biceps tendon Brachial a. Ulnar a. Pronator radii teres m. Flexor carpi radialis m. Palmaris longus m. Flexor carpi ulnaris m. Flexor sublimis digitorum m. Median n. Outer tendon of flexor sublimis digitorum m. Ulnar a. Ulnar n. Anterior carpal a. TRIANGLE OF ELBOW, FLEXOR SUBLIMIS DIGITORUM MUSCLE, RADIAL ARTERY, AND RADIAL NERVE, 135 THE FRONT OF THK FOllF.ARM. 137 which pass beneath the anterior annular ligament, where they are arranged in two pairs, one hehind the other. The {interior pair go to the middle and ring fingers. and the posterior pair to the index and little fingers. The tendons are inserted into the middle of the sides of the second phalanges of the four fingers. Each tendon splits to permit the passage of the tendon of the flexor profniidus digitorum muscle between its segments, which will be seen in the dissection of the hand. This muscle is covered by the pronator radii teres, the flexor carpi radialis, the palmaris longus, and the flexor carpi ulnaris, also by the radial vessels and nerve and the deep fascia. It rests upon the flexor profundus digitorum, and the flexor longus pollicis, the ulnar vessels and nerve, and the median nerve. Its inner edge is against the flexor carpi ulnaris. Externally, it is overlapped by the lower end of the pronator radii teres. BLOOD SUPPLY. From the radial and ulnar arteries. XKRVE SUPPLY. From the median nerve. ACTION. It flexes the proximal interphalangeal, the metacarpo-phalangeal, and wrist joints, and assists slightly in flexion of the elbow. DISSKCTIOX. Displace the supinator longus outward in order to expose the radial artery and nerve in the upper part of the forearm. Separate- the flexor carpi ulnaris from the flexor sublimis digitorum and study the relations of the ulnar vessels and nerve. Then sever the pronator radii teres, flexor carpi radialis, palmaris longus, and flexor sublimis digitorum, about one and one-half or two inches below the internal condyle, without cutting the median nerve, ulnar artery, or ulnar nerve. Reflect these muscles in order to obtain a vie\v of the structures beneath namely, the flexor profundus digitorum, flexor longus pollicis, pronator quadra tus, median nerve, ulnar vessels, and anterior interosseous vessels and nerve. The flexor profundus digitorum arises from the upper two-thirds of the front and inner side of the shaft of the ulna, and at its upper end interdigitates with the brachialis anticus in the same manner as that muscle at its origin does with the deltoid. It also arises from the inner side of the coronoid process of the ulna, and by the aponeurosis from the upper two-thirds of the posterior hprder of the ulna, in common with the ulnar origin of the flexor carpi ulnaris, and from the ulnar half of the interosseous membrane. It divides into four tendons, which pass down the forearm and continue, side by side, under the anterior annular ligament, behind the tendon of the flexor sublimis digitorum to the bases of the terminal phalanges, passing between the segments of the tendons of the flexor sublimis digitorum. A lumbricalis muscle is attached to each one of these tendons in the palm. The flexor profundus digitorum muscle lies beneath the flexor sublimis digitorum and flexor carpi radialis muscles, the ulnar vessels and nerve, and the median nerve. It rests upon the ulna, the interosseous membrane, and the pronator quadratus 138 *ri!(;i( eomites, and at its middle one-third has the radial nerve upon its outer side. Filaments of the musculo-cutaneous nerve are Ill SURGICAL ANATOMY. closely related to its lower part as it courses around the wrist. Its branches in ihe forearm are the radial recurrent, muscular, superficialis vohe, and the anterior carpal: at the wrist, the posterior carpal, the metacarpal, the dorsalis pollicis, and the dorsalis indicis ; and in the hand, the princeps pollicis. radialis indicis, perforating, palmar interosseous, and recurrent carpal. We will, at ihis lime, con- sider only ihose branches given oil' in the forearm. The radial recurrent arises from the outer side of ihe radial arterv, passes downward between the supinator brevis and supinator longus muscles and lietwcen the radial and posterior interosseous nerves ; thence upward, in company with the musculo-spiral nerve, between the brachialis anticus and supiualor longus, both of which it in part supplies. It anastomoses with the terminal branches of the superior profunda in front of the external eondyle and between the two last-named muscles. From its arch it sends muscular branches to the supinator and the extensor muscles, some passing beneath the latter to anastomose with the inter- osseous recurrent branch of the posterior interosseous. It also supplies the elbow- joint. The muscular branches arise from the radial in its downward course and supply the muscles upon the radial side of the forearm. The superficialis volae arises from the radial artery near the wrist, and passes over the ball of the thumb. Sometimes it runs beneath the abductor pollicis muscle. It supplies the muscles of the ball of the thumb and often anastomoses with the ulnar artery to assist in the formation of the superficial palmar arch. When the superficialis vola3 arises higher than visual and runs beside the radial, it would give the palpating finger the sensation of a double pulse. The anterior carpal arises from the radial artery near the lower margin of the pronator qnadratus, whence it passes inward to anastomose with the anterior carpal branch of the ulnar artery, thus forming a prc-carpal loop, the anterior carpal arch, from which branches descend to nourish the wrist-joint. The posterior carpal, metacarpal, dorsalis pollicis, and dorsalis indicis will be described with the back of the wrist and hand. The ulnar artery, larger than the radial, is the other terminal branch of the brachial artery. It at once turns toward the ulnar side of the forearm, and readies it one-third of the way down, after which it skirts the ulnar border of the forearm to the wrist. A line drawn from a point one-half of an inch below the middle of the bend of the elbow to the junction of the upper with the middle one-third of the ulnar border of the forearm will represent the course of the upper or deep portion of this vessel. A line drawn from a point midway between the internal eondyle and the middle of the bend of the elbow to the radial side of the pisiform bone will represent the course of the artery in the lower two-thirds of the forearm. It PLATE XXXIX, Inferior profunda a. Anastomotica magna a. Posterior ulnar recurrent a. Anterior ulnar recurrent a. Common Interosseous a. Anterior interosseous a. Ulnar a Anterior carpal a. Posterior carpal a. Recurrent carpal a Deep palmar arch Palmar Interosseous a Superficial palmar arch Dorsal interosseous a. 10 achial a. Superior profunda a, Radial recurrent a. Interosseous recurrent a. Radial a Oblique ligament Posterior interosseous a. nterosseous membrane Anterior carpal a. Superficialis volae a. Dorsalis pollicis a. Posterior carpal a. Priceps pollicis a. Dorsalis indicis a. Radial indicis a. Digital a. Meta caroal a. ARTERIES OF. FOREARM AND HAND. 145 THE /7,'O.VV OF Till-: FOHK.IHM. 1-47 crosses the anterior annular ligament on the radial side of the pisiform bone, and runs across the palm, forming the superlicial palmar arch, which is usually com- pleted by anastomosis with the superlicialis vohe. The ulnar artery is dec]) in its upper half, being covered hy all of the superficial flexors except the flexor carpi ulnaris ; in its lower half it is more superficial, being overlapped hy the tendon of the flexor carpi ulnaris, while immediately above the wrist it is subcutaneous, and lie-- between the tendon of the flexor carpi ulnaris and the innermost tendon of the flexor sublimis digitorum. It lies, from above downward, upon the braehialis anticus, flexor profnndus digitorum, and the anterior annular ligament. It has two vena- eomites. At its upper part the median nerve crosses in front of it, while the ulnar nerve is upon the inner side of its lower two-thirds. In the upper third of the course of the artery the ulnar nerve lies some distance to its ulnar side. When the ulnar artery has a high origin from the brachial, it usually lies upon the superficial flexor muscles, instead of beneath them, and is thus more liable to injury. Its branches in the forearm are the anterior ulnar recurrent, posterior ulnar recurrent, common interosseous, and muscular; at the wrist, the anterior and posterior carpal ; in the hand, the" deep or communicating branch ; it continues as the superficial palmar arch. As in the case of the radial artery, we will now consider only the branches given off in the forearm. The anterior ulnar recurrent artery arises from the ulnar, immediately below its origin, and passes inward and upward upon the braehialis anticus, and, behind the pronator radii teres, to the front of the inner condyle of the humerus, where it anastomoses with the anastomotica magna and the inferior profunda arteries. The posterior ulnar recurrent artery, larger than the anterior ulnar recur- rent, arises below that vessel and passes inward and backward under the flexor sublimis digitorum. It then, courses between the two heads of the flexor carpi ulnaris, in relation with the ulnar nerve, to the back of the inner condyle. It supplies the elbow-joint, ulnar nerve, and adjacent muscles, and anastomoses with the inferior profunda, anastomotica magna, and interosseous recurrent arteries. The common interosseous artery is the largest and shortest branch of the ulnar. It is given off opposite the tuberosity of the radius, whence it passes downward and outward to the upper margin of the interosseous membrane and divides into the anterior and 'posterior interosseous arteries. The anterior interosseous artery, accompanied by vena? eomites and the anterior interosseous nerve, descends along the middle of the front of the interosseous membrane, between the flexor longus pollicis and the flexor pro- fundus digitorum, and supplies nutrient branches to both muscles and to the radius and ulna. It eventually perforates the interosseous membrane, beneath MS xrilGICAL ANATOMY. the upper border of the pronator quadratus. to reach tlic back of the forearm. I'nder the upper border of the pronator <|iiadratus it gives oil' a hranch which supplies tliis muscle and anastomoses with the anterior carpal branches of the radial and nlnar and the recurrent carpal branches of the deep palmar arch. In the upper part of the forearm it also gives of]' a long slender branch which accompanies the median nerve and is called the comes nervi mediani, or median \ skin of tln> palm, except on the uhiar side, and communicates with the ulnar palmar cutaneous branch. The radial nerve is one of the terminal branches of the nmseulo-spiral. It passes along the front of the outer side of the forearm, accompanying the radial artery along the outer side of its middle one-third. In the upper part of its course it is overlapped by the belly of the snp'mator longus, and about three inches above the wrist curves backward under the tendon of that muscle and pierces the deep fascia, at the outer border of the forearm, to divide into an external and an internal branch. These supply the skin of the back of the hand and lingers. The ulnar nerve, emerging from between the olecranon and the internal enndyle of the humerus in the upper part of the forearm, passes down the anterior and inner side of the forearm upon the flexor profundus digitorum and beneath the belly of the flexor carpi ulnaris, while in the lower part of its course it lies to the radial side of the flexor carpi ulnaris muscle and its tendon. It has upon its radial side, as far down as the pisiform bone, the lower two- thirds of the ulnar artery. While in the forearm the ulnar nerve gives off articular, muscular, cutaneous, and dorsal cutaneous branches, and not infre- quently it communicates with the median nerve. The articular branches are given off, behind the internal condyle, to supply the elbow-joint, and, just above the carpus, to supply the wrist-joint. Of the muscular branches, the one to the flexor carpi ulnaris arises in the upper part of the forearm ; the other arises lower down, and passes to the inner part of the flexor profundus digitorum. The cutaneous branches are two small nerves arising, by a common trunk, in the middle of the forearm. The shorter, and more superficial, descends to the skin of the ulnar side of the wrist, pierces the deep fascia, and joins a branch of the internal cutaneous, while the other, a deeper branch, accompanies the ulnar artery lying upon its anterior surface, to supply the skin of the ulnar side of the palm of the hand. This branch communicates with twigs from the median, and is called the palmar cutaneous branch. The dorsal cutaneous branch arises about three inches above the wrist and passes backward, under the flexor carpi ulnaris, to the posterior surface of the wrist, where it pierces the deep fascia and divides into a communicating and two digital branches, which supply the skin and fascia of the ulnar side of the hand, both sides of the little finger, and the adjacent side of the ring finger. The communicating branch inosculates with the posterior branch of the internal cutaneous and the digital branches with the adjacent ones from the radial nerve. 152 SURGICAL A \ ATOMY. THE FKOXT OF Till-: II AM). DISSECTION. Tin- skin lias been incised across the front of Ihc wrist. From the inner end of Iliis incision make another along (lie ulnar bonier of tlie |)alin as far as the junction of the latter with the little linger. From the outer end of the transverse incision make a third along the radial border of the thenar eminence to the base of the first phalanx of the thumb, then around the palmar surface of the thumb, and along the radial border of the palm to its junction with the index linger. The Hap of integument thus marked out is reflected downward, exposing the superficial fascia. In dissecting the thumb and fingers the skin is incised in the median line and reflected laterally. The skin of the palm is sensitive and well supplied with sweat glands, sebaceous glands being absent. Superficial fascia. The superficial fascia of the palm is dense and thin, and closely connects i lie skin with the deep fascia, resembling in this respect that of the scalp and sole of the foot. That covering the thenar and hypothenar eminences is more delicate. The fat in the palm of the hand presents a somewhat lobulated appearance, and when an incision is made through the skin, small masses of adipose tissue protrude through the opening. It contains the palmaris biv vis muscle, the ulnar vessels and nerve, the palmar cutaneous branches of the ulnar and median nerves, and the superficial transverse ligament. The palmaris brevis muscle is embedded in the granular superficial fascia on the ulnar side of the palm. It consists of a series of slightly divergent fasciculi, which arise from the central palmar fascia and the anterior annular ligament, pass OVQT the hypothenar eminence, and are inserted into the skin of the ulnar border of the palm. NERVE SUPPLY. From the ulnar nerve. The ulnar vessels and nerve occupy the superficial fascia on the radial side of the pisiform bone, where their deep branches are given off. Palmar cutaneous nerves. Trace the palmar cutaneous branches of the median, radial, and ulnar nerves to their termination. That of the median passes between the tendons of the flexor carpi radialis and palmaris longus and over the anterior annular ligament. It supplies the hollow of the palm and the adjacent border of the thenar eminence. The palmar cutaneous branch of the ulnar nerve passes into the hand in front of and accompanying the ulnar artery, and supplies the ulnar side of the hollow of the palm. The radial palmar cutaneous supplies the outer margin of the thenar eminence. The superficial transverse ligament is a band of fibers which crosses the roots and webs of the fingers and connects the slips of the central portion of the palmar fascia. PLATE XLI, Superficial fascia SUPERFICIAL PALMAR FASCIA. 153 PLATE XLII. J -Palmaris brevis m. -Deep palmar fascia ' -Dip-ital a. Collateral digital n. DEEP PALMAR FASCIA AND PALMARIS BREVIS MUSCLE. 156 Till-: ril7 DISSKCTIOX. In ivinoving the superficial palmar fascia begin at the wrist and work toward tlic digital clefts and dissect it free from (lie underlying deep palmar fascia. This exposes fas anterior annular /ii/mm at of the wrist, a thickened band of the deep fascia of the forearm, which extends from the pisiform and the hook of the uiiciform bone, upon the ulnar side of the wrist, to the tuherosity of the scaphoid and the ridge of the t rape/him upon the radial side of the wrist. It is firm, dense, and unyielding, gives origin to most of the muscles of the thenar and hypothenar eminrnn's, and converts the hollow of the front of the wrist into a tunnel for the passage of some of the structures of the forearm which are destined for the front of the hand. It is crossed by the following structures, enumerated in their order, from the ulnar to the radial side : The tendon of the flexor carpi ulnaris, part of which it receives for insertion; the ulnar nerve, situated at the radial side of that tendon; the ulnar artery and its venae comites ; the palmar cutaneous branches of ulnar and median nerves ; the palmaris longus, part of which it receives for insertion ; and the tendon of the flexor carpi radialis, which passes over its upper margin and then pierces it. The tunnel beneath the ligament gives passage to the following structures: The tendons of the flexor sublimis digitorum and flexor profundus digitorum, the tendon of the flexor longus pollicis, and the median nerve. The great carpal or palmar bursa. In this tunnel there are two synovia! sacs, separated by the median nerve; the outer invests the tendon of the flexor longus pollicis and extends upon the first phalanx of the thumb ; the inner invests the tendons of the flexor sublimis digitorum and flexor profundus digito- rum and extends to the middle of the palm. Upon the proximal two phalanges of the fingers the flexor tendons are also invested by a synovial sheath which lines their fibrous sheaths. The synovial sheath on the little finger is usually described as being continuous with the inner sac of the great carpal bursa, while the synovial sheaths on the tendons of the index, middle, and ring fingers cease at the heads of the metacarpal bones and do not communicate with the great carpal bursa. The arrangement of these sheaths probably differs somewhat in individuals. Schiiller states that only exceptionally does the sheath for the little finger communicate with the main or inner synovial sac. These sacs form what is called the great carpal bursa, which extends about an inch into the forearm. The great carpal bursa, when distended, is constricted in the middle by the anterior annular ligament, which gives it an hour-glass shape. Inflammation of the sheath of the flexor tendon, over the proximal phalanx of the thumb, may, by extension, involve the outer sac of the great carpal bursa, while inflammation of the sheath of the flexor tendons of the little finger may implicate the inner sac. When the two sacs communicate in front of the median 158 SURGICAL ANATOMY, nerve, which they occasionally do, inflammation of one is readily communicated to the other. Purulent collections in the invent carpal hursa re([iiire early and live incision, with, in some cases, division of the anterior annular ligament. Purulent collections in the sheaths of the ilexor tendons of the index, middle, and ring fingers, by reason of the anatomic condition, would not extend into the palm further than the heads of the metacarpal hones. The deep palmar fascia is intimately united to the skin in the middle of the palm, and less so at the side's. It is divided for description into a central and two lateral portions. The /< iifnil /iniilnii is dense and strong, and protects the underlying vessels, nerves, and tendons from injury. Its strength is greatest in those who are accustomed to handling heavy implements. It is triangular in shape and narrow at its origin from the lower border of the anterior annular ligament, where it is strengthened by the broadened tendon of the palmaris longus. It expands in its passage through the palm to divide into four digital slips, one going to the base of each finger; not uncommonly an additional slip passes to the thumb. Each slip divides to permit the passage of the digital flexor tendons, the divisions being then inserted into the sides of the bases of the first phalanges and the deep transverse ligament which connects the heads of the metacarpal bones of the fingers. Each slip is also continuous with the fibrous sheath of the ilexor tendons. At the point of division into its four digital processes, the fascia is strengthened by transverse fibers. Through the spaces between the primary divisions of the fascia pass the digital vessels and nerves and the lumbricales tendons. This central portion of the palmar fascia is closely united to the skin of the palm by many small, short, fibrous bands, which prevent the integumentary covering from being thrown into folds and from gliding to and fro during the various movements of the hand. From either side of the central portion a process of fascia dips into the palm to join the deep transverse layer of fascia which covers the interossei muscles, the deep palmar arch, and the metacarpal bones, thus separating the muscles of the thenar and hypothenar eminences from the center of the palm. This central fascial com- partment contains the superficial palmar arch and its branches, the digital branches of the median nerve, the outer digital branch of the ulnar nerve, the superficial and deep flexor tendons, and the lumbrical muscles. This fascial compartment maybe compared to a box the ends of which are open and correspond to the tunnel under the anterior annular ligament, above, and to the intervals between the primary and secondary divisions of the central palmar fascia, below. It is of surgical signifi- cance. A collection of pus in this compartment would point in the forearm above the anterior annular ligament, at the clefts of the fingers, or upon the dorsum of the hand over the interosseous spaces, rather than upon the palm, because of the density of the central palmar fascia. The deep transverse layer of the palmar PLATE XLIII. Radial a S'jperficiaiis vof'ae a Outer head of flexor brevis pollicis Abductor pollicis m. . Opponens poliicis m. Inner head of flexor brevis pollicis Adductor pollicis m. Tendon o* flexor longus pollic Umar a. Ulnar n. Palrparfi iongus tendon Deop branch of ulnar n. Deep b'anch of ulnar a Anterior annular ligament Abductor minim' digiti m, Loop between median and ulner nerves Flexor brevis minimi digit! m. Superficial palmar arch Digita 1 arteries Digital nerves Flexor subl'mis digitorum tendon Interosseous a. Collateral digital a. Collateral digital n. Flexot profundus digitorum tendon SUPERFICIAL PALMAR ARCH AND DIGITAL NERVES. 159 THE 1-'1:<>\T OF THE HAM). 161 fascia oilers sonic resistance to the passage of pus toward tin 1 dorsum of the hand. Contraction of the digital slip, passing to the ring or little linger, Ilexes the linger upon the palm at tlie metacarpophalangeal joint and produces the deformity known as Dupuytren's contraction of the linger. In these cases Ihe fibrous hand heroines prominent under the overlying skin, which often presents transverse folds over the contracted fascia. This condition can only he relieved hy subcutaneous or open section of the offending slip. The lull rii/ portions of the palmar fascia are thin, and continuous with the central palmar fascia and the fascia of (lie dorsum of the hand; they cover the muscles of the theiiar and hypotheiiar eminences. DISSECTION. Divide the expansion of the palmaris longus and reflect the Central palmar fascia toward the lingers, noting its deep processes located upon either side. The structures of the palm now exposed are : The superficial palmar arch and its hranches. the median nerve and its divisions, the superficial and dee], flexor tendons, and the lumhrical muscles. Upon cither side of the palm are the muscles composing the thenar and liypothenar eminences. The superficial palmar arch is formed hy the terminal part of the ulnar artery, and is completed by the superficialis voloe, or a branch from the radialis indicis or princeps pollicis, and sometimes, though rarely, by a large median artery. It com- mences at the lower border of the pisiform bone, where the ulnar artery gives off the deep or communicating branch which passes backward between the abductor minimi digiti and flexor brevis minimi digiti muscles to complete the deep palmar arch. It curves across the 'palm to the thenar eminence, where it is joined by the branch or branches which complete it. The convexity of the arch is directed toward the ringers, its lowest point corresponding to a line drawn transversely across the hand from the lower border of the strongly abducted thumb. The superficial palmar arch lies upon the short muscles of the little finger, the flexor tendons, and the digital branches of the median nerve, and is covered by the palmaris brevis, the palmar cutaneous branches of the median and ulnar nerves, and the central palmar fascia. Its branches are the four digital arteries. The digital branches arise from the convexity of the arch ; they supply the nlnar side of the little finger, and the adjacent sides of the little, ring, middle, and index fingers. The first digital artery is joined by a branch from the deep palmar arch and passes over the liypothenar eminence, to which it sends hranches, and under the inner digital branch of the ulnar nerve. It supplies the ulnar side of the little finger. The second, third, and fourth dif/ital arteries pass to the intervals between the fingers, where they are joined by the interosseous branches of the deep palmar arch and anterior perforating branches of the dorsal interosseous arteries and divide beneath the superficial transverse ligament, about one-quarter of 11 ir.i> vriUiH'AL ANATOMY. an inch above tin- clefts of the tinkers, into two collateral digital brandies tor the supply uf the adjacent sides of the lingers. At their commencement they lie over the superficial lle.xor tendons ; hut as they approach the clefts of the lingers, thev course between them in company with the digital nerves, and also between the primary slips of the central palmar fascia with the nerves superficial to the arteries. As the digital arteries lie over the interosseous spaces, palmar abscesses should be opened in the line of (be melacarpal bones. 1'pon the side of the finder the col- lateral digital artery is behind the nerve. The collateral digital arteries of each finger unite to form an arch across the front of the finger a little beyond the terminal joint, and from this arises an arterial plexus which supplies the pulp of the end of the finger and the matrix of the nail. Small twigs go to the inter- phalangeal joints, the integument and sheaths of the tendons, and form arterial plexuses, one being in front of each joint. The ulnar nerve crosses the wrist in front of the .interior annular ligament upon the ulnar side of the ulnar artery, between the artery and the pisiform and unciform bones, where it rests in a groove between these bones protected thereby from pressure. It divides into a superficial and a dee]) branch. The superficial branch passes along the ulnar side of the palm, supplying the skin of this region and the palmaris brevis which covers it. It divides into a communicating and two digital branches. The inner digital branch supplies the inner side of the little linger; the outer divides into collateral digital branches to supply the adjacent sides of the little and ring fingers. The communicating branch joins the inner- most digital branch of the median nerve. The deep branch of the ulnar nerve accompanies the profunda branch of the ulnar artery, and passes backward between the abductor and flexor brevis minimi digiti muscles, through the oppo- nens minimi digiti, and upon the distal side of the deep palmar arch. It supplies the short muscles of the little finger, all of the interossei, the two ulnar lumbricales, the adductor pollicis, and the inner or deep head of the flexor brevis pollicis. The median nerve enters the hand beneath the anterior annular ligament enveloped by the synovial sheaths of the flexor tendons of the hand ; it ivsts upon the tendons, spreads out slightly, and bifurcates into an external and an internal division as it emerges from under the ligament. The r.iii'i'iiii/ ii gives off muscular branches to the abductor and opponens pollicis, and outer head of the flexor brevis pollicis, after which it divides into two digital branches; the /iiitrnnoxl supplies a collateral branch to either side of the thumb, while the iinicrnn^t goes to the radial side of the index finger and sends a small twig to the first lumbrical muscle. The internal division, larger than the external, divides into an outer and PLATE XLIV. Supirator longus m MuSCUlo-Spr Brachialis ar.t Brachial a. Posterior interosseous Radial n Radial reccurrent a. Supinator brevis m. Radial a. Extensor carpi < Supinator longus m. (displaced) Extensor carpi radialis brevtor m Pronator radii te r es m (cut 1 - Radial origin of flexor sublimus digitor Radial n Flexor longus pollicis Anterior Interosseous a, piercing intero Anterior carpal ft. Superficialis volae a. Abductor pollicis m/cut) Opponens pollicis m. Abductor indicis m Radialis indicis a. Lumbrica! m.(cut) Princeps pollicis a. ch of anastomotica magna a. ian n. rachialis anticus m . fascia. ondylotd origin of flexors iceps tendon. ad of pronator radii teres m. .nterior ulnar recurrent a. 'osterior ulnar recurrent a. nterior interosseous n. ommon interoseous a. 'osterior interosseous a. iterior interosseous a. exor carpi ulnaris m. (displaced) nar n. nar a, or profundus digitorum m. (displaced) eous membrane. taneous branch of ulnar n. uadratus m. (cut) anch of anterior interosseous a. nch of ulnar n. anch of ulnar a. brevis minimi digiti m.( branch of ulnar n. p palmar arch. onens minimi digiti m. uctor minimi digiti m. erosseous m , Adductor pollicis m.(cut) terosseous a. Digital a. ARTERIES AND NERVES OF FRONT OF FOREARM. 163 PLATE XLV, Flexor profundus digitorum tendon - Flexor sublimis digitorum tendon" Transverse metacarpal iig._ Vaginal or fibrous sheath- Flexor sublimis digitorum tendon Flexor profundus digitorum tendon Theca reflected upon flexor tendons Fibrous sheath (everted) Ligamenta longa Ligamenta brevia Great carpal bursa anti FIBROUS AND SYNOVIAL SHEATHS OF FLEXOR TENDONS. 166 THE mo\T or rni-: IIA.\D. i<>7 an inner digital branch. Tin- outer digital sends a branch to the second hinihrical muscle and divides into two collateral branches, which supply the adjacent sides of the index and middle fingers as well as the dorsnm of these lingers. The inner digital, in addition to communicating with the nlnar nerve, divides into two collateral branches, which supply the' adjacent sides of the middle and ring lingers, and also, occasionally, the third Inmhrical muscle. Kach collateral branch sends branches to the dorsnm of the tinkers, and that of the middle linger is almost entirely supplied by these nerves. At first the digital nerves are beneath the snpevlici.il palmar arch and the digital branches arising therefrom, but they gradually become more superficial, and, along the sides of the lingers, lie in t'vont of the collateral digital avteries. At the tips of tlie lingers they give oil' anterior twigs to supply the pulp of the linger, and on the posterior aspect, twigs which supply the matrix of the nail. Very careful dissection discovers, upon the liner ramifications of the collateral branches of the digital nerves, minute seed-like enlargements known as the J'acinian bodies a form of nerve terminus. The flexor tendons cross the wrist in a large compartment beneath the anterior annular ligament, the outermost being that fov the jlr.rnr Imii/nx pul/irix, which pusses outward along the thumb. The four tendons of the jli.rm- xn/,lii/iix ilif/itarnii) lie in the tunnel beneath the anterior annular ligament, arranged in two pairs, one being anterior to the other. The anterior pair go to the middle and ring fingers: the posterior, to the index and little fingers. Of the tendons of the flexor j>i-i>fini\. Cut the muscle transversely at its middle, and reflect. The opponens pollicis is small and triangular, and is subcutaneous in its outer part, while its inner portion is covered by the abductor pollicis. It arises, beneaili the abductor, from the front of the anterior annular ligament and the trapezium, whence its fibers diverge for insertion into the radial side of the entire length of the mctacarpal bone of the thumb. It is covered by the abductor pollicis and the deep fascia. It lies upon the joint between the trapezium and the metacarpal bone of the thumb and on the radial side of the superficial or outer head of the flexor brevis pollicis. I'.i.oon SriTLY. From the radial and superficial volar arteries. XKUVK SriTLY. From the median nerve.. ACTION. It draws the head of the metacarpal bone of the thumb toward the head of the metacarpal bone of the little finger, after which contraction of tin- long and short flexors brings the end of the thumb in contact with the base of the little finger. The flexor brevis pollicis arises by a superficial and a deep head, between which passes the tendon of the flexor longus pollicis. The aujH'i-Jii-inl //'r: lower end of the radius. \\\ means of these processes six eoinpartnients are formed for the pa>sage of the extensor tendons. They contain, from within out- ward, the tendons of the following muscles: The extensor carpi ulnaris. ihe extensor of the little finder (extensor minimi digiti), (lie extensor communis digi- torum and extensor indicis, the extensor secmidi internodii pollicis. the extensor carpi radialis longior and brevior, the extensor primii internodii pollicis, and extensor ossis metacarpi pollicis. Kach of these coin])artments has a synovial lining which extends above and below the limits of the ligament. The sheaths of tlu- extensor tendons, particularly those of the thumb, are not infrequently the site of inflammation (teno-synovitis), and in such cases there is a longitudinal swelling over the position of the tendon, due to increase in the amount of secretion in the synovial sheath. There is, also, a grating or crepitating sensation commu- nicated to the surgeon's linger when the patient contracts the various muscles (tenalgia crepitans). Tubercular teno-synovitis may also occur here. Connected with the tendon sheaths, or, more commonly, with the periarticular structures of the -wrist, we often meet with small, firm, oval, or round swellings which are rendered more prominent by flexion of the wrist, and are known as ganglia. They are more common in young girls. The extensor sheaths of the tendons of the back of the hand are practically prolongations of the walls of the different compartments of the posterior annular ligament. They hold the same relations as the compartments, and inclose the same tendons which have been described as occupying the compartments of the posterior annular ligament. The muscles exposed are the extensors of the hand and fingers. They consist of three sets the radial, superficial, and deep extensors. Radial extensors. Supinator longus, extensor carpi radialis longior, and extensor carpi radialis brevior. The supinator longus, supinator radii longus or brachio-radialis, arises from the upper two-thirds of the external condyloid ridge of the humerus, as high up as the musculo-spiral groove, and from the external intermuscular septum. It is a long fleshy muscle, the belly of which, with the other two muscles of this group, forms the prominence of the outer side of the forearm. Its flattened tendon is inserted into the base of the styloid process of the radius. It is wholly sub- cutaneous except at the lower part of its tendon, where it its crossed obliquely by the extensores ossis metacarpi and primi internodii pollicis. It rests upon the musculo-spiral nerve, the radial recurrent artery, the radial vessels and nerve, the humerus, the supinator brevis muscle, the extensores carpi radialis longior and brevior muscles, and the insertion of the pronator radii teres. On its inner side above the elbow are the braehialis anticus muscle, musculo-spiral nerve, and radial IDS SURGICAL ^^. \TOMY. recurrent artery ; and below the elbow, the tendon of the biceps and the pronator radii tores. I>L(>OI> Sri'i-i.Y. From the radial and radial recurrent arteries. XKKVK SriTLV. From the musculo-spiral nerve. ACTION. It slightly supinates the forearm, especially after full pronation, flexes the forearm, and in full supination is a slight pronator. The extensor carpi radialis longior arises from the lower third of the external condyloid ridge of the humerus, the external intermuscular septum, and from the external condyle of the humerus by the common extensor tendon; the filters terminate about the middle of the forearm in a flattened tendon, which passes do\vn the outer side of the forearm to the wrist, and through a groove upon the back of the base of the radius just behind the styloid process, accompanied by the extensor carpi radialis brevier, to be inserted upon the radial side of the base of the metacarpal bone of the index finger. The muscle is overlapped on its outer 'anterior border by the supinator longus. and crossed at its lower end by the three extensors of the thumb. It lies upon the elbow-joint, extensor carpi radialis brevior, and dorsum of the wrist. BLOOD SrrpLY. From the radial and radial recurrent arteries. NKKVK SI'PPLY. From the nmscnlo-spiral nerve. ACTION. It extends and abducts the wrist and flexes the elbow. The extensor carpi radialis brevior arises from the external condyle of the humerus, the adjacent intermuscular septum, the external lateral ligament of the elbow-joint, and the deep fascia. In the middle of the forearm it ends in a flattened tendon which lies close to and accompanies that of the extensor carpi radialis longior down the forearm. It passes through the groove upon the base of the radius and is inserted into the radial side of the base of the metacarpal bone of the middle finger. It and the tendon of the extensor carpi radialis longior occupy the same sheath and pass through the same compartment of the posterior annular ligament. Above it is covered by the extensor carpi radialis longior, and below by the extensors of the thumb. It rests upon the supinator brevis, the insertion of the pronator radii tores, the radius, and carpus; and upon its nlnar side is in contact with the extensor communis digitorum. BLOOD SrppLY. From the radial and radial re-current arteries. N KRVE SuppLY.-'-From the posterior interosseous nerve. ACTION. It extends the wrist and, feebly, the elbow. Superficial Extensors. The extensor communis digitorum, the extensor minimi digiti, the extensor carpi ulnaris, and the anconeus. The extensor communis digitorum muscle arises, by the common extensor tendon, from the external condyle of the humerus, the deep fascia, and adjacent PLATE LV. Triceps tendon Dinar n Posterior ulnar recurrent a Flexor carpi ulnaris m. Flexor piofundus digitorum m Extensor carpi ulnaris tendon Posterior interosseous n. Posterior carpal a. Ganglion of Wrisberg Radial a.- WL i I Biceps in. Brachialis anticus m. .Supinator iongus m. Superior profunda a. Extensor carpi radialis longior m. Musculo-spiral n, Anconeus m.(cut) Posterior interosseous recurrent a. -Supinator brevis m. Posterior interosseous n. -Posterior interosseous a. Extensor ossis metacarpi pollicis m. Radius Extensor carpi radialis brevior tendon Extensor carpi radialis longior tendon Extensor primi internodii pollicis m. Extensor secundi internodii pollicis m. Extensor indicis m. Extensor carpi radialis longior tendon Extensor carpi radialis brevior tendon Posterior carpal a. Dorsales pollicis a. Metacarpal a. Dorsalis indicis a. DEEP MUSCLES OF BACK OF FOREARM, POSTERIOR INTEROSSEOUS ARTERY AND NERVE, 200 THE r.ACK OF THE FOREARM. -'01 intermuscular septa. Just below the middle of the forearm it divides into three tendons which pass, with the extensor indicis, through a common compartment in tin' posterior annular ligament, whence they diverge for insertion into the hases of the second and third phalanges of the four fingers. The muscle is subcutaneous, except where its tendons pass heneath the posterior annular ligament, and lies upon llie supinator hivvis, extensors of the thuiiih and index finger, the posterior interosseous nerve and vessels, the carpus and tlie dorsal interossei muscles. On its ulnar side are the extensor minimi digiti and extensor carpi ulnaris. Ui.ooD SUPPLY. From the posterior interosseous artery. XF.KVE SUPPLY. From the posterior interosseous nerve. ACTION. Its chief function is to extend the phalanges; continuing its action it extends the wrist-joint and, to a slight extent, the elbow. The extensor minimi digiti muscle lies upon the ulnar side of the extensor connnunis digitorum muscle, and is generally connected therewith. It arises from the external condyle of the htimerus by the common extensor tendon, from the deep fascia, and the adjacent intermuscular septa. It becomes tendinous in the lower part of the forearm, and passes behind the radio-uluar joint through a separate compartment of the posterior annular ligament of the wrist. It passes to the back of the little finger after uniting with the tendon of the extensor connnnnis digitorum. It is covered above by the extensor communis digitorum and extensor carpi ulnaris, but is superficial below, except where it lies beneath the posterior annular ligament. It rests upon the supinator brevis, the extensor ossis metacarpi pollicis, the extensor secundi internodii pollicis, and the extensor indicis. BLOOD SUPPLY. From the posterior interosseous artery. NERVE SUPPLY. From the posterior interosseous nerve. ACTION. It extends the wrist-joint, the metacarpo-phalangeal and the intcr- phalangeal joints of the little finger. The extensor carpi ulnaris muscle arises, by the common extensor tendon, from the external condyle of the humerus, from the middle third of the posterior border of the ulna in common with the flexor carpi ulnaris and flexor profundus digitorum, and from the deep fascia. It lies, superficially, upon the ulnar side of the forearm, and ends in a tendon which goes through a groove, back of the styloid process of the ulna and beneath the posterior annular ligament, to be inserted into the base of the metacarpal bone of the little finger. It is subcuta- neous, except where it lies beneath the posterior annular ligament, and rests upon the supinator brevis, extensor ossis metacarpi pollicis, and extensores primi and secundi internodii pollicis, extensor indicis, the ulna, and the carpus. Its ulnar border is in relation with the anconeus and the posterior border of the ulna ; its radial border with the extensor minimi digiti. 202 SURGICAL ANATOMY. BLOOD SriTLY. From the posterior intcrosscous artery. XKI;VK Si'i>ri,Y. From the posterior iniemsseous nerve. ACTION. It extends the elbow-joint and adducts and extends the wrist-joint. The anconeus is a small and triangular-shaped muscle, situated upon the outer side of the olecranon. It arises from the hack of the external condvle of the humerus and the posterior ligament of the elbow-joint. From this origin its libers diverge for insertion into the outer side of the olecranon and upper one-fourth of the shaft of the ulna. It is superficial and lies against the elbow-joint, the orbicular ligament, the ulna, and a part of the supinator brevis. Its upper edge is in contact with and parallel to the lowermost fillers of the outer head of the triceps; its lower and outer margin adjoins the extensor carpi ulnaris. BLOOD SUPPLY. From the interosseous recurrent artery. NKKVK SUPPLY. From the musculo-spiral nerve. ACTION. It extends the elbow-joint. DISSECTION. The extensor communis digitorum, extensor minimi digiti, and extensor carpi ulnaris should now be severed in the middle of the forearm, and reflected upward and downward so that greater facility for the study of the follow- ing muscles may be afforded. Deep Extensors: Supinator brevis, extensor ossis metacarpi pollicis, ex- tensor primi internodii pollicis, extensor secundi internodii pollicis, and extensor indicis. The supinator radii brevis or supinator brevis is a broad, flat muscle, irregular in outline, and wrapped about the upper end of the radius. It arises from the external condvle of the humerus, the external lateral ligament of the elbow-joint, the orbicular ligament of the radius, the depression below the lesser sigmoid cavity of the ulna, and the fascia enveloping the muscle. Its upper libers, arranged as a loop, surround the neck of the radius, and are inserted into the back of its inner surface, while the remainder of the muscle is attached to the anterior and outer surface of the radius, from the oblique line and bicipital tuberosity to the insertion of the pronator radii teres. It is covered in front and externally by the biceps, pronator radii teres, supinator longus, extensores carpi radialis longior and brevier, and the radial vessels and nerve; behind by the anconeus, extensor communis digitorum, extensor minimi digiti, extensor carpi ulnaris, and the int ei-. 209 and olccranon process of the ulna: it anastomoses with the superior ii anastomotica magna, radial recurrent, and posterior ulnar recurrent arteries. The iiiiixciiltti- lii-iuii-liix of the posterior interosseous artery supply the muscles I -t\veen which it lies. The ni-ticulni- /irnit<-licx supply the wrist-joint. The tn-iiiiiKtt /ifiiii'ni <,f tlif anterior interosseous artery is seen lying on the posterior surface of the lower part of the interosseous membrane, where il is joined hy a hranch of the posterior interosseous artery. ll runs downward over the wrist, heneath the extensor tendons, and anastomoses with the posterior carpal arch. The posterior interosseous nerve winds around the outer side of the upper end of the radius, through the substance of the supinator hrevis muscle, to the hack of the forearm, whence it passes downward, in company with the posterior interosseous artery, between the superficial and deep extensor muscles, to the upper border of the extensor secundi internodii pollicis. In the forearm it supplies nii/xrulfii- /irinir/ii'x to the extensor carpi radialis brevior, supinator brevis, extensor conimunis digitorum, extensor minimi digiti, extensor carjii ulnaris, extensor ossis metacarpi pollicis, extensores primi and secundi internodii pollicis, and extensor indicis. At the upper border of the extensor secundi internodii pollicis muscle the posterior interosseous nerve leaves the posterior interosseous artery and runs beneath the extensor secundi internodii pollicis and extensor indicis, upon the interosseous membrane, and accompanies the terminal part t of the anterior inter- osseous artery to the back of the wrist. Here it ends in a ganglitbnn enlargement which gives off articular filaments to the wrist and intercarpal joints. After blows upon the front of the external condyle or outer side of the upper one-fifth of the radius, the condition of the posterior interosseous nerve may cause spasm or paralysis of the supinator brevis and the extensors of the wrist and ringers, excepting the radial extensors which are supplied by branches of the musculo-spiral before it bifurcates. THE BACK OF THE HAND. The superficial veins, nerves, and deep fascia of the back of the hand having been described when the posterior surface of the forearm was considered, it remains to reflect the deep fascia from above downward in order to expose the extensor tendons and remaining deep structures of the back of the hand. The extensor tendons emerge from beneath the posterior annular ligament and diverge for insertion into the backs of their respective digits. Those of the 14 210 SURGICAL A \.\TOMY. extensor communis digitorum become narrow ami thickened opposite the nieta- carpo-phalangeal joints, at which point they give off fasciculi which arc attached to the lateral ligaments of these articulations. They then form a broad aponeurosie which covers the entire back of the iirst phalanges, where they are joined by the tendons of the intcrossei and lumbricales muscles. Opposite the first interphalan- gcal joint each tendon divides into a middle slip which is inserted into the base of the second phalanx, and two lateral .slips which unite over the middle phalanx. for insertion into the back of the base of the terminal phalanx. These tendons constitute the posterior ligaments of the metacarpo-phalangeal and interphalangeal joints. On the proximal side of the metacarpo-phalangeal articulations the tendon of the ring finger sends off two lateral divergent slips, which arc attached to the adjacent tendons of the little and middle fingers. This is important because it restricts the independent extension of the ring finger, a defect especially troublesome in pianists and violinists, who, sometimes, by reason of this interference with the required movement, have these restricting bands divided. The tendon of the middle linger is also connected to the extensor communis tendon of the index finger by a band of transverse fibers. The tendon of the extensor indicis joins that of the common extensor over the first phalanx of the index finger. The tendon of the extensor minimi digit i divides, one part joining the common extensor tendon of the little linger, the other, ending in the dorsal expansion common to this tendon and that of the tendon of the extensor communis digit orum. DISSKCTJOX. Remove the fascia overlying the dorsal interossei muscles and the vessels of the back of the wrist and hand. The vessels on the back of the wrist and band are the radial artery and its branches, which will be described below, the posterior carpal branch of the ulnar artery, and the terminal portion of the anterior interosseous artery. The radial artery, as it leaves the front of the forearm, first lies upon the external lateral ligament of the wrist, then upon .the scaphoid, trapc/ium, and base of the metacarpal bone of the thumb, and under the tendons of the extensoivs ossis m eta carpi, primi internodii, and secundi internodii pollicis, whence it continues to the apex of the interval situated between the metacarpal bones of the thumb and index-finger, where it passes, between the two heads of the first dorsal interos- seous muscle, into the palm. On the back of the wrist it gives off the posterior carpul, metacarpal or first dorsal interosseous, dorsalis pollicis, and dorxulix ////\\ dorsal digital branches which supply the contiguous sides of the middle, ring. and little fingers. At the carpal ends of the interosseous spaces they are joined by the perforating brunches of the deep palmar arch. At the distal ends of the interosseous spaces they give oil' mili'fio,- ji, rji- joint, there are two synovial saes. This membrane lines the ligaments of the joint and fades away at the margin of the articular cartilage, where it is continuous with the surface of the cartilage. The synovial membranes resemble serous membranes, and, like them, are composed of flat endothelial cells. They secrete the synovial fluid which lubri- cates the joints. Inflammation of joints begins in this membrane more frequently than in other parts of the joint. Because of the dose relation between the mem- brane and the ligaments, the latter are likely to be involved. In tubercular arthritis the softening of the ligaments permits increased lateral motion of the joint, whereas the infiltration and contraction of the ligaments and bands of adhe- sions in rheumatic arthritis cause stillness and false ankylosis of the joint. For practical purposes all joints maybe divided into three classes: Those which derive their strength chiefly from the conformation of the bones, those whose strength depends upon their ligaments, and those which largely depend upon surrounding muscles for support. The hip-joint is the best example of the first class. ICxternal violence applied to such a joint is more likely to produce a contusion than a sprain or dislocation. In joints of the second class, such as the radio-ulnar, a sprain is more common than a contusion or a dislocation. In joints of the third class, the best example of which is the shoulder, dislocation is more common than contusion or sprain. In the diagnosis of fractures, dislocations, and diseases of joints of the extrem- ities it is always advisable to compare the affected with the non-affected member. JOINTS OF THE UPPER EXTREMITY. The joints of the upper extremity include the sterno-clavicular, the scapulo- clavicular, the shoulder or scapulo-humeral, the elbow, the superior and infe- rior radio-ulnar, the radio-carpal or wrist, the intercarpal or medio-carpal, the carpo-metacarpal, the metacarpo-phalangeal, and the interphalangeal. THE STERNO-CLAVICULAR JOINT. The sterno-clavicular, an arthrodial joint, is formed by the upper outer part of the manubrium stern i and the inner end of the clavicle, which is larger than the bed or articulating surface of the manubrium in which it rests. The first costal cartilage gives attachment to one of the ligaments of the joint. These parts 216 SURGICAL ANATOMY. are bound together by five ligaments : The anterior sterno-clavicular, the posterior sterno-clavicular, the interclavicular, the costo-clavicular or rhomboid, and the interarticular fibro-cartilage. The anterior sterno-clavicular ligament, which covers the front of the joint, is a fibrous membrane extending from the superior and anterior surface of the inner end of the clavicle to the superior and anterior surface of Hie inanubrium sterni. It is covered by the skin, the fascia', and the sternal origin of the stern o- cleido-mastoid, and it is in relation posteriorly with the intern rtictilar libro-cartiiage and the two synovial sacs. The posterior sterno-clavicular ligament is attached to the hack of the inner end of the clavicle and to the manubrium sterni in a manner similar to that of the anterior ligament. Anterior to the ligament are the interarticular fibro- cartilage and the two synovial sacs ; posterior to it arc the sterno-hyoid and sterno- thyroid muscles. The interclavicular ligament is a strong fibrous band which varies consider- ably in size, and extends from the superior surface of the sternal end of one clavicle to the same part of the other. It is attached to the superior surface of the manu- brium sterni between the ends of the clavicles, and is covered in front by the skin and fascia 1 , while behind it is in relation with the sterno-thyroid muscles. The costo-clavicular (rhomboid) ligament, short, flat, and quadrangular in shape, is attached below to the upper surface of the inner end of the cartilage of the first rib, and above to the rhomboid depression on the under surface of the sternal end of the clavicle. It lies behind the tendon of origin of the subclavius muscle and in front of the subclavian vein. In order to expose the interarticular fibro-cartilage sever the costo-clavicular and the anterior sterno-clavicular liga- ment. The interarticular cartilage, a flat disc nearly corresponding in size and outline to the sternal end of the clavicle, is situated between the end of the clavicle and the clavicular notch of the sternum, where it acts as a buffer and prevents the clavicle from being pushed inward over the sternum. Below it is attached to the first chondro-sternal junction, and above to the upper and back part of the inner end of the clavicle, where it blends with the interclavicular ligament and the anterior and posterior ligaments. It is thinnest in the center, and thickest at its upper posterior part. The joint is divided by this fibre-cartilaginous disc into two compartments, each one of which has a separate synovial sac. These sacs, the inner of which is the larger, sometimes communicate by means of an opening present in the cartilage. BLOOD SUPPLY. Derived from the internal mammary, superior thoracic, and supra-scapular arteries. PLATE LIX, Spine of scapula Conoid ligament Frapezoid ligament Inferior acromio-clavicular ligament Superior acromio-clavicular ligament Coraco-acroinlal ligament Coraco-humeial ligament Transverse ligament Long head of biceps m. Capsular ligament SCAPULO-GLAVICULAR, ACROMIO-CLAVICULAR, AND SCAPULO-HUMERAL JOINTS.-ANTERIOR VIEW, 218 PLATE LX, Coraco-acromial ligament Superior acromio-clavicular ligament Conoid ligament Transverse ligament- Trapezoid ligament Long head of biceps m. Cut edge of capsular ligament Glenoid ligament Glenoid cavity - f -Long head of triceps m SCAPULO-CLAVICULAR AND AGROMIO-CLAVICULAR JOINTS, AND GLENOID LIGAMENT, 219 JOINTS OF THE UPPER EXTREMITY. 221 NERVE SUPPLY. The nerve supply of the joint is derived from the branch of the bnichial plexus which supplies the subclavius muscle. MOVEMENTS. This joint is the center of motion for the shoulder, and admits of cdrcumduction and of limited movement upward, downward, forward, and backward. Dislocation of the clavicle at this articulation does not often occur, for the combined strength of the ligaments is considerable, and compensates for the lack of adaptation of the articular surfaces of the bones. The adjacent muscles assist in preventing luxation. THE SCAPULO-CLAVICULAR JOINT. The scapulo-clavicular, an arthrodial joint, is formed by the acromial end of the clavicle and the acromion process of the scapula. The bones are held in place by the ligaments proper, which are the superior acromio-clavicular, the inferior acromio-clavicular, and the iuterarticular fibro-cartilage. The coraco-clavicular is an accessory ligament. The superior acromio-clavicular ligament covers the upper surface of the joint and is attached to the contiguous margins of the two bones. It is quadri- lateral in shape, and composed of parallel transverse fibers which interlace with the tendinous fibers of the trapezius and deltoid muscles. It is covered by skin and fascia?. The inferior acromio-clavicular ligament is the counterpart of the preceding, covers the under surface of the joint, and is similarly attached. Below it is in relation with the tendon of the supra-spinatus muscle. These two ligaments are continuous around the joint and constitute its capsule. An interarticular nbro-cartilage sometimes exists in this joint. When present it is rarely a complete disc, and occupies the upper part of the joint. There is but one synovial membrane. The cartilage when present can be exposed by dividing the superior acromio-clavicular ligament. The coraco-clavicular ligament composed of two parts, the trapezoid and conoid connects the clavicle and the coracoid process of the scapula. The trape- zoid ligament, the anterior of the two, is quadrilateral in shape, and is attached to the upper surface of the coracoid process and to the oblique ridge on the under surface of the clavicle. Behind it is continuous with the conoid ligament, while in front and externally it has a free margin. The conoid ligament, triangular in shape, is attached by its apex to a rough impression upon the base of the coracoid process on the inner side of the trapezoid ligament ; by its base to the conoid tubercle, and for half an inch to a ridge on the under surface of the clavicle. In front and externally the conoid ligament is continuous with the trapezoid. 222 SURGICAL ANATOMY. Tliis ligament is in relation with the subclavius and deltoid muscles in front, and with areolar tissue, i'at, and the insertion of the t rape/his behind. MOVKMKXTS. This joint permits a slight gliding, rotatory, or forward and backward movement, limited by (lie two portions of the coraco-clavicular ligament. Upward dislocation of the outer end of the clavicle is not uncommon; it is characterized by an undue prominence of the outer end of the bon BLOOD SUPPLY. The nourishment of the joint is derived from the supra- scapular, acromio-thoracic, and posterior circumflex arteries. NERVE SUPPLY. The supra-scapular and circumflex nerves supply the articulation. The ligaments proper of the scapula are the 1 coraco-acromial and the trans- verse ligaments. The coraco-acromial ligament, triangular in shape, is attached by its base to the entire outer border of the coracoid process ; by its apex to the tip of the acromion process. It completes the coraco-acromial arch, which is above the head of the hnmerus. It is covered by the clavicle and deltoid muscle and separated from the capsular ligament of the shoulder-joint by a bursa. The transverse or supra-scapular ligament bridges over the supra-scapular notch, converting it into a foramen which gives passage to the supra-scapular nerve. The supra-scapular vessels pass over it. In dislocation of the scapula the inferior angle of the bone slips from under the upper portion of the latissimn.s dorsi muscle, and the condition which results is "winged scapula." The causes are general weakness of the muscles, as in pulmonary tuberculosis and paralysis of the serratus inagnus muscle. The inferior angle is normally held against the chest by the latissimus dorsi and serratus inagnus, consequently any condition which weakens these muscles allows this angle to project. In the treatment of this condition the scapula should be held against the chest by a broad belt, so that the extent of movement of the arm will not be much restricted. The condition of the muscles may be improved by massage, electricity, and hypodermic injection of strychnin. THE SHOULDER-JOINT. The shoulder, an enarthrodial or ball-and-socket joint, is formed by the glenoid fossa of the scapula and the head of the humerus, which are united by the capsular and coraco-humeral ligaments. The glenoid fossa is deepened by the glenoid ligament which is attached to its margin. The deepened glenoid fossa is much smaller than the head of the humerus, to allow of greater freedom of motion. JOINTS OF THE UPPER EXTHEMITY. The capsular ligament is attached to the margin of the glenoid cavity of the scapula and to the anatomic neck of the huinerus. Tlie capsule is very loose, or sacciform, to permit free movement ; it is thickest above. The capsular ligament is perforated at three points : Above, where the bursse beneath the tendons of the infra-spinatns and subscapnlaris communicate with tin- shoulder-joint, and on the outer side, where the long tendon of the biceps pierces it between the tuberosities oft lie linmerus. The three e said to form two joints, a superior and an inferior; and to be connected in three places, at the superior and inferior articulations and throughout the length of their shafts. The Superior Radio-ulnar Articulation, a pivot-joint, is formed by the recep- tion of the head of the radius into the lesser sigmoid cavity of the ulna. But one ligament, the orbicular, is found at this joint. It encircles the head of the radius in the form of a complete ring, as it passes from the anterior to the posterior border of the lesser sigmoid cavity. It also suspends the head of the radius, as its lower circumference is less than its upper, and it is therefore funnel- shaped. It is intimately blended with the anterior, posterior, and external lateral ligaments of the elbow-joint. The supinator brevis muscle is afforded a partial origin from this ligament. The synovial membrane of this articulation is continuous with that of the elbow-joint. BLOOD AND NERVE SUPPLY. Derived from the same sources as those of the elbow-joint. The Inferior Radio-ulnar Articulation, a lateral hinge-joint, is formed by the reception of the head (lower end) of the ulna into the sigmoid cavity situated on the inner side of the base of the radius. A thin layer of cartilage covers the articular surfaces of the bones. The ligaments of the joint are the anterior and posterior radio-ulnar and the triangular nbro-cartilage. The anterior radio-ulnar ligament is narrow, and passes from the anterior border of the sigmoid cavity of the radius to the front of the head of the ulna. The posterior radio-ulnar ligament is similarly attached to the back of the joint. The triangular fibro-cartilage separates the head of the ulna from the cuneiform bone and the sigmoid cavity of the radius. It is attached, by its apex, to the depression at the base of the styloid process of the ulna, and by its base to the lower end of the radius, along the lower margin of the sigmoid cavity. It is united by its margin to the carpal ligaments. Its apex is thick and its base thin ; it is concave above, being thicker at its edges than at its center. At times the center is perforated, in which event the synovial sac of this joint is continuous with that of the wrist-joint. When, from traumatism or disease, this cartilage becomes detached from the radius, the resulting deformity 2:\\ SURGICAL .I.V.I TO MY. is an abnormal projection of the head of the ulna, a condition frequently cncoun- tt.Tcd as a complication and sequel of Colics' fracture. The synovial membrane of this joint is so loose that it has been aptly called the sacciform membrane; this laxity is necessary to permit the rotation of the base of the radius about the head of the ulna during pronation and supination. The triangular tibro-cartilage follows the base of the radius in its movements around the head of the ulna. ULOOD SriTT.Y. The nourishment of the joint is derived from the anterior intorosseous artery and the anterior carpal arch. XioiiVK SrriM.v. From the anterior and posterior interosseous nerve-. The shafts of the radius and ulna are also connected by the oblique ligament and the interosseous membrane. The Oblique ligament, often absent, is a round slip which passes from the outer part of the coronoid process of the ulna to the radius below the tuberosity. Its direction is downward and outward. It lies above the upper border of the interosseous membrane, its fibers running in a direction at a right angle to those of the membrane. The interosseous membrane is attached to the interosscous borders of the radius and ulna, and stretches across the interval existing between these bones. It is deficient above. The anterior interosseous vessels pass through an opening located near the lower end of this membrane to reach the back of the forearm. The posterior interosseous artery passes between the upper border of the inter- osseous membrane and the oblique ligament to the back of the forearm. The interoers radiate slightly to the luliercle of the scaphoid and the ridge of the trape/ium, while others pass to the dorsal surface of the scaphoid. The external lateral ligament is in relation with the radial artery and the tendons of the exten- sores ossis inetacarpi pollicis and primi internodii pollicis ; the artery lies hetween the tendons and the ligament. The internal lateral ligament (ulnocarpnl) extends from the extremity of the styloid process of the ulna to the inner surface of the cuneiform bone, the pisi- form hone, and the anterior annular ligament. It is fan-shaped, its lihers radiat- ing to a more marked degree than do those of the external lateral ligament. The lower part of the ligament can readily be divided into two fasciculi, one of which passes to the inner side of the cuneiform bone, the other to the pisiform bone and anterior annular ligament. The tendon of the extensor carpi ulnaris passes over the posterior part of the ligament. The anterior ligament (anterior radio-carpal) is a broad, thick membrane which is attached above to the lower end of the radius, its styloid process, the triangular fihro-cartilage, and ulna; and below to the palmar surface of the scaphoid, semilunar, and cuneiform bones. A few of the fibers are continued downward to the os magnum and unciform bones. In relation with the anterior surface of the ligament are the tendons of the flexor profundus digitorum and flexor longus pollicis, while in contact with the posterior surface is the synovial membrane of the joint. Numerous small vessels pierce the ligament. The posterior ligament (posterior radio-carpal), not so strong as the anterior, extends from the posterior surface of the lower end of the radius and triangular fibro-cartilage to the posterior surface of the scaphoid, semilunar, and cuneiform bones. It is strengthened by fibers from the back of the fibro-cartilage, and also by the fibrous sheaths of the extensor secundi internodii pollicis and radial exten- sors. The other extensor tendons, which are in relation with the posterior surface of the ligament, also add to its strength. The anterior surface is in relation with the synovial membrane. The synovial membrane lines the ligaments of the joint from which it is reflected to the margins of the articular surfaces entering into the formation of the joint. It is very lax on account of the free movement of the joint. It does not communicate with the inferior radio-ulnar joint, except when the triangular fibro-cartilage is perforated. It is not in communication with the carpal joints owing to the intervention of the interosseous ligaments. In acute synovitis of the wrist-joint there is pain, and as the joint is super- 238 vrnnicAL AXATOMY. iicial. heat ami redness are also present. Swelling is nio-t pronounced on the dorsal surface as the subcutaneous tissue is more loosely arranged in that location, and there may he bulging het\veen the extensor tendons. Acute syiHivitis is differentiated from teno-synovitis, or inflammation of the sheaths of the tendons, by the fact that when the wrist-joint is lixed the tinkers can, in the former '-ondj- tion, 1)0 moved without producing pain, and if a teno-synovitis exists, movement of the fingers causes pain. In front of the wrist-joint are the flexor tendons of the hand, and behind are the extensors. The numerous tendons which pass over the wrist-joint, and the ill irons extensions from their sheaths, serve to strengthen an otherwise ill protected articulation. MOVKMKNTS. The movements of the wrist-joint are very similar to those of a ball-and-socket joint, the main difference being that the wrist does not possess rotation. This loss of rotation is overcome by the pronation and supina- tion of the forearm, which is effected by means of the radio-ulnar articulation-. BLOOD STPPLY. Derived from the anterior and posterior carpal arches, the anterior and posterior intcrosseous, and the recurrent carpal branches of the deep palmar arch. NERVE SUPPLY. Derived from the ulnar and the posterior interosseous nerves. DISSECTION. To expose the articular surfaces of the joint, cut the anterior and lateral ligaments transversely and strongly extend the hand. THE CARPAL JOINTS. The articulations of the bones of the carpus are divided into three sets viz., those between the bones of the first row, those between the bones of the second row, and the articulation between the two rows. The ligaments of the first row of carpal bones are two dorsal, two palmar, two interosseous fibro-cartilages, and the capsular ligament connecting the pisiform and cuneiform bones. The two dorsal ligaments connect the dorsal surfaces of the bones the scaphoid with the semilunar and the semilunar with the cuneiform. The two palmar ligaments connect the anterior surfaces of the bones the scaphoid with the semilunar and the semilunar with the cuneiform. The palmar ligaments are stronger than the dorsal. The two interosseous fibro-cartilages are two strips of cartilage which con- nect the adjacent surfaces of the scaphoid and semilunar, and the semilunar and cuneiform. They fill in the interstices between the bones and help form the smooth convex surface for articulation with the radius and triangular fibro- cartilage. The pisiform bone is attached to the cuneiform by a capsular ligament. PLATE LXV. SECTION OF JOINTS OF WRIST AND HAND. 239 JOLXTS OF Till': I'l'l'Kl! KXTlll'.M 1TY. -> 41 This articulation has a separate synovial membrane. The pisiform i-< also attached to the unciforni by a strong palmar band, the />ix<>-ii,i<-!niitc lii/min nt. and to the base of the iil'tli metacarpal bone by another strong palmar band the />ix<>- nnli(aii-[>nl Hi/in, a nt. These palmar bands might lie regarded as prolongations from the tendon of the Hexor carpi ulnaris ; and the pisiform as a sesamoid bone in that tendon. The synovial membrane is an extension of that lining the joint between the first and second rows of carpal bones. The ligaments of the second row of carpal bones are three dorsal, three palmar. and two interosseons. The three dorsal ligaments connect the dorsal surfaces of the bones of the second row the trapezium with the trapezoid, the trapezoid with the os magnum, and the os magnum with the unciform. The three palmar ligaments connect the palmar surfaces of the bones of the second row in the same manner as do the dorsal ligaments. The palmar ligaments are stronger than the dorsal. The two interosseous ligaments connect the unciform with the os magnum, and the os magnum with the trape/.oid. At times there is a third interosseous ligament found between the trapezium and the trapezoid. The synovial membrane is an extension of that lining the joint between the first and second rows or the medio-carpal joint. The Medio-carpal Articulation is formed by the union of the two rows of carpal hones. The line of articulation is composed of three' distinct parts on the outer side the scaphoid of the first row articulates with the trapezium and the trapezoid of the second row ; in the middle the scaphoid and the semilunar of the first row form a cup-shaped cavity into which the head of the os magnum and the superior margin of the unciform of the second row are received ; on the inner side the cuneiform of the first row articulates with the unciform of the second. The two rows of the carpus are held in place by four ligaments the anterior medio-carpal, the posterior medio-carpal, the internal lateral, and the external lateral. The anterior medio-carpal ligament connects the palmar surfaces of the bones of the first row with those of the second. Most of the fibers extend from the first row to the os magnum, others connect the scaphoid to the trapezium and the trapezoid, while the remaining ones pass from the cuneiform to the unciform. The posterior medio-carpal ligament consists of fibers which pass obliquely from the first to the second row. It is not uniform throughout, being stronger on the ulnar side. 16 2-\-> SURGICAL A ^. \THMY. The external lateral ligament connects the sc.-iphoid \vitli the trapezium. The internal lateral ligament connects tlie cuneiform with the nnciibrm. The synovial membrane of the carpus lines the medio-carpal joint, ami sends two prolongations upward between the scaphoid and semilunar and the semilnnar and cuneiform bones. It sends downward three extensions which line the joints of the second row, the earpo-metaearpal joints of the four inner inetacarpal bones, and till' joints between the bases of these inetacarpal bones. MOVEMENTS of the carpal joints are limited, to a great extent, to the motions of ilexion and extension. There is allowed a gliding motion which i.s antero- posterior, and a very .slight degree of rotation between the articulation of the os magnum with the scaphoid and the semilunar. BLOOD SUPPLY. The carpal articulations are nourished by the anterior and posterior carpal branches of the radial and ulnar arteries, by the anterior inter- osseous, and the recurrent carpal brandies of the deep palmar arch. NEKVK STPPLY: Derived from the ulnar, the median, and the posterior interosseous nerve. DISSECTION. To expose the articulating surfaces of the medio-carpal joint and the interosseous ligaments divide the dorsal and lateral ligaments and strongly ilex the hand. CAi;?( >-MKTACARPAL ARTICULATIONS. The articulations between the carpal and inetacarpal bones may be divided into two sets the junction of the four inner inetacarpal bones with the unciform, os magnum, and trape/oid ; and the articulation of the inetacarpal bone of the thumb with the trapezium. In the First Set the metacarpal bone of the index finger articulates with the trape/oid, that of the middle finger with the os magnum, and the ring and little lingers with the unciform. The ligaments connecting the bones are dorsal, palmar, and interosseous. The dorsal ligaments are stronger and more distinct than the palmar. They connect the dorsal surface of the respective carpal bones with the dorsal surface of the inetacarpal bones. The inetacarpal bone of the index finger has two fasciculi one from the trapezium, the other from the trape/oid ; that of the middle finger has two one from the trapezoid and one from the os magnum ; that of the ring finger has two one from the os magnum and one from the unciform ; that of the little finger has but one from the unciform. The palmar ligaments are somewhat similar to the dorsal. The metaearpal bone of the index linger has one fasciculus from the trapezium, under cover of the flexor carpi radialis ; that of the middle finger has three one from the os PLATE LXVI. Metacarpal bone- -Metacarpal bone Lateral process of common extensor tendon- Synovial membrane- Lateral ligament- -Transverse metacarpal ligament Proximal phalanx- Extensor tendon. Lateral ligament- -Proximal phalanx .Anterior Interphalangeal ligament .Flexor sublimis digitorum tendon Lateral ligament- Extensortendon- -Anterior Interphalangeal ligament -Flexor profundus dfgitorum tendon METACARPO-PHALANGEAL AND INTERPHALANGEAL LIGAMENTS (MIDDLE FINGER). 244 JOINTS OF THE UPPER EXTREMITY. magnum, one from the trapezium, and a third from the imciform and the base .of the fifth mcta carpal ; the ring and little fingers have one each from the uncifonn. The interosseous ligament is found only in one part of the joint. It connects the adjacent angles of the unciform and os magnum with the metacarpal bones of the middle and ring fingers. The synovial membrane is a continuation of that lining the medio-carpal joint. At times there is a separate synovial lining for the articulation of the unci- form with the fourth and fifth metacarpal bones. BLOOD SUPPLY. The carpo-metacarpal joint of the index finger is nourished by the radial, the metacarpal, the dorsalis indicis, and the radialis indicis artery ; of the middle and ring fingers, by the anterior and posterior carpal arches and the deep palmar arch ; of the little finger, by the ulnar artery and its deep branch and, also, the posterior carpal arch. NERVE SUPPLY. From the deep palmar branch of the ulnar, from the median and posterior interosseous nerves. The Second Set consists of the articulation between the metacarpal bone of the thumb and the trapezium. But one ligament, the capsular, connects these bones. The ligament is a loose capsule which extends from the margin of the articu- lar surface of the trapezium to that of the metacarpal bone. It is stronger on its dorsal aspect. The synovial membrane is separate from that of the carpal and the other carpo-metacarpal joints. MOVEMENTS of the carpo-metacarpal joint of the four inner metacarpal bones are slight ; that of the little finger is most free, followed by that of the ring finger. The articulations of the index and middle fingers are almost immovable. The carpo-metacarpal joint of the thumb is allowed the greatest freedom of motion by the shape of the articulating surfaces of the bones. BLOOD SUPPLY. This joint is nourished by the radial, dorsalis pollicis, and princeps pollicis arteries. NERVE SUPPLY. From the median nerve. THE INTERMETACARPAL ARTICULATIONS. The metacarpal bones of the four fingers are held together at each end by ligaments. The lateral articular surfaces, at their carpal extremities, are held in apposition by dorsal, palmar, and interosseous ligaments. The dorsal and palmar ligaments are attached to the respective surfaces of the bones. 246 SURGICAL AXATOMY. The interosseous ligaments pass between the lower margins of the adjacent articulating surface-. The synovial membranes of these joints are extensions of the common carpal synovial membrane. BLOOD SI:ITLY. From twigs of the palmar and dorsal interosseons arteries. NERVE STI-PLY. From the ulnar and posterior interosseous nerves. The distal extremities or heads of the four inner metaearpal bones are held in place by the transverse ligament, which is situated on the anterior or palmar surface. It is a fibrous band consisting of three fasciculi, which connect the second and third, the third and fourth, and the fourth and fifth bones. It blends with the glenoid ligament of the mctacarpo-phalaiigeal articulations. The interosseous muscles pass behind it to reach their points of insertion, while the digital arteries and nerves and flexor tendons and lumbrical muscles pass in front of it. The Metacarpo-phalangeal Articulations. The head of each metaearpal bone is received into a cup-shaped cavity on the proximal end or base of the cor- responding phalanx. They are held in place by an anterior (glenoid) and two lateral ligaments. The anterior (glenoid) ligament is a dense, fibrous plate which is firmly attached to the base of the first phalanx and loosely attached, by areolar tissue, to the head of the metaearpal bone. It deepens the articular surface of the base of the phalanx. Its margins are continuous with the lateral ligament, the transverse metaearpal ligament, and the fibrous sheath of the flexor tendon. The lateral ligaments are strong short bands, situated on either side of the joint, that connect the tubercle and depression on the side of the head of the meta- earpal bone to the base of the phalanx. Anteriorly they are continuous with the anterior ligament and. posteriorly, with the expansion of the extensor tendon. The synovial membrane is very loose. The posterior surface of the joint is covered by an expansion of the extensor tendon, which serves the purpose of a dorsal ligament. MOVEMENTS of these joints include flexion, extension, adduction, and abduction. BLOOD SUPPLY. Derived from the digital and palmar interosseous arteries. NERVE SUPPLY. Derived from the digital nerves. The articulation between the head of the metaearpal bone of the thumb and the base of the phalanx is different from those of the fingers, on account of the shape of the articulating surfaces. The head of the metaearpal bone of the thumb is wider than the heads of the metaearpal bones of the fingers, and instead of being rounded, has an irregularly raised palmar edge, upon which are two facets i>47 for sesanioid bones. The ligaments are two lateral and a posterior. The ligaments are sliort, fibrous hands which connect the adjacent ends of the articu- lating hones. The jin.ffi i-'nir ligament passes across I he joint and connects the two lateral ligaments. The sesamoid bones, two in number, rest on the facets on the head of the metacarpal bone of the thumb, in the tendons of the flexor brevis pollicis. They are connected by transverse libers which cover the front of the joint. BLOOD SUPPLY. Derived from the princeps pollicis and dorsales pollicis. XKKVK SUPPLY. Derived from the digital branches of the median and radial nerves. THE IXTERPHALAXGEAL ARTICULATIONS. The ligaments of the interphalangeal articulations consist of an anterior (gleiioid) and two lateral. The anterior (glenoid), like that of the metacarpo-phalangeal joint, is loosely attached to the proximal bone, but very firmly to the distal. It blends with the lateral ligaments. The flexor tendons pass over the anterior ligament, The two lateral ligaments are strong bands which connect the sides of the proximal phalanx with the lateral aspect of the distal phalanx. Posteriorly, the extensor tendon covers the joint and takes the place of a posterior ligament. The tendon blends with the lateral ligaments to com- plete the capsule around the joint. The synovial membranes of these joints are lax. MOVKM KNTS of the interphalangeal joints are limited to extension and tlexion ; flexion being much more free than extension. Lateral movement is prevented by tenseness of the lateral ligaments. BLOOD SUPPLY. Derived from the collateral digital arteries. NERVE SUPPLY. From the collateral digital nerves. DISLOCATIONS. It has been shown, in the description of the ligaments of the various joints, that the bones forming the articulations are so firmly held in place that it is almost impossible to have a luxation, or dislocation, without tearing one or more of the ligaments. At times the tiasues surrounding the joint may become so lax and so stretched that without rupture of any of the ligaments they will allow a displace- ment of the bones composing the joint. The muscles play a very important part IMS SURGICAL ANATOMY. in the reduction of lnxation>. By manipulating tlu' dislocated nuMiilici 1 so Unit the muscles will have an opportunity to return to tlieir normal condition from the Overstretched state caused by the luxation, the displaced member can, more easily. lie reduced. Dislocations should be reduced as som after the injury :is possible, because after swelling and inflammation have developed reduction is more difficult, and early reduction lessens the probability of subsequent disability. The clavicle may be dislocated at either end. Luxations at the sternal end may be forward, forward and upward, forward and downward, or upward. A backward displacement is rarely, if ever, si-en. In complete luxation of the sterno-clavicular joint it is probable that the anterior and posterior sterno-clavicular and the inlerclavicnlar ligament will be ruptured. The costo-clavieular ligament will also stiller to a greater or less extent. The interarticular fibi'o-cartilage may remain attached to either of the bones. Dislocation of the clavicle at the acromial end is much more frequent than at the sternal end. In most cases there is but a partial dislocation. The capsular ligament formed by the superior and inferior aeromio-clavicular ligaments is torn, while the conoid and trapexoid ligaments remain intact but are stretched. In complete luxation the conoid and trapezoid ligaments are more or less torn. The trape/.ius muscle then tends to pull the distal end of the clavicle upward, section of the libers of the trapezius often being required to allow reduction to be maintained. Dislocations of the humerus are very frequent, owing to the great freedom of motion at the shoulder, the exposed position of the joint, and because the joint depends- for its strength chiefly upon the elasticity and tonic contraction of the surrounding muscles; consequently, when the muscles are relaxed and force is suddenly applied to the joint directly by a blow upon the shoulder, or indirectly by a fall upon the hand or elbow, the head of the humerus slips out of the glenoid cavity. Four varieties are usually described : Three anterior subcoracoid, sub- glenoid, and subclavicular ; and one posterior the subspinous. In the aiitii/fciiniil /ii.i'iifinn the head of the humerus makes nts escape from the glenoid cavity by tearing through the lower part of the capsular ligament. The head of the humerus is then found in the axilla, resting upon the triangular part of the axillary border of the scapula, immediately below and a little in front of the glenoid cavity and between the tendon of the subscapularis and that of the long head of the triceps muscle. The superior part of the capsule is tightly stretched across the glenoid cavity. In many cases the tendon of the long head of the biceps will be torn. The muscles attached to the tuberosities of the humerus are put on the stretch or are lacerated. Thus the supru-spinatus muscle is PLATE LXVII, DISLOCATED SHOULDER AND NORMAL SHOULDER. 249 DISLOCATIONS OF THE UPPER EXTREMITY. 251 stretched or lacerated ; the inftaspirtatus, suhscapularis, and coraco-brachialis are generally put oil the stretch ; the deltoid muscle is in extreme tension and draws tlin elbow away from the body ; the teres major and the teres minor are relaxed. The rotundity of the shoulder is lost, and a flatness is present owing to the displacement of the greater tuberosity, which allows an undue prominence of the acromion process to exist and causes the formation of a transverse depression below it. The circumflex nerve, which curves over the lower margin of the subseapularis muscle and around the surgical neck of the humerus is liable to injury, producing paralysis of the deltoid. Atrophy of the deltoid is caused by disuse, as in ankylosis of the shoulder-joint; more frequently by diseases of the spinal cord, as acute anterior polio-myelitis ; by ascending neuritis of the circum- flex nerve usually due to disease of the shoulder-joint and causing paralysis of the muscles; and by injury of the circumflex nerve by a blow or fracture of the upper part of the humerus. On account of the relation of the contents of the axilla to the head of the dislocated humerus there may be injury to the nerves and vessels of this space ; the axillary artery or vein may be ruptured ; the brachial plexus of nerves has been stretched so much that a partial paralysis followed the dislocation. This dislocation and fracture of the anatomic neck of the scapula are the only injuries about the shoulder in which the arm is lengthened. In the aubcoracoid, the most frequent luxation, the head of the bone escapes through a tear in the anterior part of the capsule, and rests below the coracoid process upon the anterior surface of the neck of the scapula. There is, generally, injury to the coraco-brachialis and the short head of the biceps, the conjoined tendon of origin of which muscles will be found to rest on the anterior surface of the head of the bone. In the subclavicular luxation the head of the bone escapes through a tear in the anterior portion of the capsule, and rests below the clavicle against the chest, beneath the pectoralis major and minor muscles. In both the subcoracoid and subclavicular luxations the deltoid is greatly stretched, and the subseapularis is carried upward, with occasional rupture of its attachment to the lesser tuberosity of the humerus. The infra-spinatus and supra-spinatus muscles are stretched and, at times, lacerated. The vessels and. nerves of the axilla are carried forward with the head of the humerus ; the stretching of the nerves causes extreme pain. The long head of the biceps has been torn. The circumflex nerve, which curves over the lower margin of the subseapularis muscle, may be severely injured by pressure, contusion, or laceration. In the subspinous luxation the head of the bone is forced through a rent in the posterior and lower part of the capsule, and rests upon the posterior surface SURGICAL -lY.I'/'O.UT. of the capsule, below the spine of the scapula aud beneath the infra-spinatus muscle. The infra-spinatus will he relaxed, but the supra-spiiiatus and snl>- scapularis stivlcheil or torn. The tendon of the long head of the hiceps and llie anterior tihers of the deltoid will he stretched, hut not ruptured. In all the lii.i'iitim/x of the J/cad of the hunierus the r<>fniulili/ of the shoulder will be lost, and jln, the most common, the head of the radius is generally found upon the front of the humerus. The anterior and external lateral ligament > are more or less torn, and the orbicular ligament is either lacerated or so stretched that it will allow complete luxation. The head of the radius may be dislocated forward by roughly jerking a child's hand, or by lifting the child by the hand. In this manner the bones of the forearm may be fractured, the deltoid muscle torn, the shoulder dislocated, or the clavicle fractured. In the backward hi .rut inn the orbicular ligament and the capsular ligament of the elbow are both torn. The oblique ligament will either be ruptured or stretched. The head of the radius is found rotating behind the external eondyle. DISLOCATIONS OF THE UPPER EXTREMITY. ->:,r, Dislocation of the upper end of the ulna alone is very rare. It is almost always associated with dislocation of the radius, or with fracture of some of the neighboring liony prominences. The anatomy is similar to that found in luxation of both bones, with the exception that the orbicular ligament is always torn, but the head of the radius holds its normal relation to the capitellum of the humerus. Dislocations of the radio-carpal joint are very rare. When they do occur, they are, generally, complicated by fracture of the radius or the styloid process of the ulna. Cases of simple luxation of the joint, either backward or forward, do occur. In the Inn- f.-ini I'd In. nit inn the posterior and lateral ligaments are torn ; the anterior ligament may remain intact, although it is often lacerated. The extensor muscles will probably be found to be torn from the bones in the lower part of the forearm, and also displaced. The nerves and arteries, in relation with the joint, are usually displaced or ruptured. The radius and ulna will present anteriorly, while the first row of carpal bones will lie behind the bones of the forearm and beneath the extensor tendons. If the luxation be compound, as it frequently is, there will be laceration of the tendons which cross the joint. If the carpus be displaced forward, the reverse position of the various bones will be held, and the flexor tendons lacerated and displaced. The anterior liga- ment will be ruptured. In both luxations the forearm is shortened. In the back- ward luxation the hand is flexed, while in the forward it is extended. In the diagnosis of dislocation of the wrist-joint the relation of the metacarpal bone of the thumb to the styloid process of the radius should be observed. If this relation be normal, no dislocation of this joint can be present. The lower end of the ulna may be dislocated either backward or forward ; this accident, uncomplicated, is rather rare. The posterior radio-ulnar and the internal lateral ligament of the wrist-joint are torn in the backward luxation, and the triangular fibro-cartilage is detached from the ulna. The head of the ulna is forced out of its socket and lies across the lower end of the radius. In the forward dislocation of the ulna the anterior radio-ulnar and the internal lateral ligament are torn, and the triangular fibro-cartilage is detached from the ulna. The head of the ulna presents on the anterior surface of the radius. The separate carpal bones are rarely, if ever, dislocated, on account of the strong surrounding tendons and firm ligaments. When any one bone of the carpus is luxated, the ligaments holding it in place will be more or less stretched, according to the extent of the displacement, and the overlying or underlying tendons will be somewhat displaced. Luxations of the metacarpal bones of the fingers and thumb are also very rare, and many surgeons are doubtful as to their ever occurring except -'><; SURGICAL A \ATOMY. as a complication. The fact that they are so firmly held in place hy the anterior annular ligament and their own ligaments, as well as hy the tle.xor and extensor tendons, will show why this accident is BO rare. Dislocations of the phalanges are frequent occurrences, and often lead to permanent deformity. Dislocation of the proximal phalanx of the thumb is an accident often seen, and is, at times, one of the most difficult to reduce. It mayoccur either as a back- ward or a forward luxation, the former being the more frequent. In the Inn-L-iniril liu-tiUn/i the proximal end of the phalanx will present on the dorsum of the metacarpal hone of the tlmmh, and the head of the latter hone will form a distinct projection on the palmar surface of the thumb. The anterior ligament is torn and lies in front of or upon the head of the metacarpal hone : the lateral ligaments may or may not be lacerated; (he tendon of the flexor longus pollicis is displaced to the ulnar side of the head of the metacarpal hone. Many reasons have been advanced to explain the frequent difficulty in reduction of this dislocation ; some of these reasons are that the neck of the metacarpal hone is held between the two tendons of the flexor brevis pollicis ; that the muscles of the thumb are so strong that it is almost impossible to overcome them ; and that the neck of the metacarpal bone is held between the lateral ligaments. Inter- position of the anterior ligament and other parts of the capsule between the articular ends of the bones is regarded by many surgeons as oii'ering the chief obstacle to reduction of this dislocation. Forirnnl Jiij-iit/ini of the proximal phalanx of the thumb is not very common. The base of the phalanx will present anteriorly, with the head of the metacarpal bone resting upon its dorsum. The lateral and anterior ligaments will either sustain severe stretching or he torn. This luxation is more readily reduced than the backward variety. In dislocation of the various phalanges of the fingers the lateral ligaments will always be stretched and possibly torn ; the anterior ligament maybe lacerated, and the tendons passing to and over the bones displaced. Before considering excisions and fractures we will consider the anatomy of the long bones without unnecessarily trespassing upon the domains of histology and osteology. The long bones, such as the hnmerus, consist of a shaft and two extremities. The shaft is composed of an outer layer of hard, compact bone which covers a PLATE LXVIII. 17 SKIAGRAPH OF FETAL SKELETON. BY M. i. WILBERT. 257 ANATOMY OF THE LONG BONES. 259 layer of cancellous bone tissue. The central portion of the shaft, throughout the greater part of its length, is occupied by the marrow which fills the medullary canal. When a bone is fractured, some of the fat globules of the marrow may enter torn veins, held open by their adherence to the walls of the bony channels, and cause fat embolism. In the extremities of the bones the whole thickness of the bone internal to the compact bone is occupied by cancellous tissue. The shaft receives its nourishment from the periosteum and from the nutrient artery which passes into the marrow; the extremities are nourished by the periosteum and the articular arteries. AVhen, in an amputation, a bone is divided above the point of entrance of the nutrient artery, the stump of the bone is supplied with nutri- tion through the periosteum and articular arteries. The periosteum is a fibrous membrane which invests the bones at all parts, except those portions which are covered by articular cartilage and give attachment to large tendons. It carries the blood-vessels which nourish the external portion of the bone. The cells next to the bone (osteoblasts) are capable of forming new bone, therefore the deeper portion is called the osteo-genetic layer of the membrane. The outer layer is composed of fibrous and elastic tissue, arranged chiefly in a longitudinal direction. In raising flaps of periosteum it is well, on account of the longitudinal direction of the fibers, to make both longitudinal and transverse inci- sions into that membrane, so that it will not split and be stripped from the bone for some distance. It has been demonstrated that the growth of a bone occurs in three ways : (1) By means of the osteo-genetic layer of the periosteum ; (2) through the epi- physeal cartilage ; and (3) through interstitial deposit or deposit by the osteoblasts in the Haversian systems. By means of the periosteum and interstitial deposit the bone grows in thickness ; through the epiphyseal cartilage and interstitial deposit, in length. A bone increases in thickness chiefly through the osteo-genetic layer of the peri- osteum and partly by interstitial deposit, and in length chiefly through the ossifica- tion of successively developed layers of cells of the epiphyseal cartilage which connects the shaft with the extremities, and to some extent by .interstitial deposit. Therefore, in amputations through bones in young persons the periosteum should not be stripped back by pulling upon the flaps when the bone is divided, and the epiphyseal cartilage should be left intact in excisions of joints. As a result of disease or injury of the epiphyseal cartilage the epiphysis sometimes unites with the shaft, and the corresponding bone of the other side gradually becomes the longer of the two. In excisions in young persons under eighteen years of age it is, therefore, important to avoid the epiphyseal cartilage, so that the limb may grow to its full length. Occasionally, after a slight traumatism the osteo-genetic layer 2W xrildH'AL AXATOMl'. of the periosteum becomes locally active, and an cxostosis develops. In acute suppnrative periostitis an early incision down to the hone i< required to allow the pus to escape, for if drainage is not provided, the periosteum is floated from the shaft of the bone from one epiphyseal line to the other, and the whole shaft dies or undergoes necrosis. The termination of the periosteum at the line of attach- ment of the ligaments, and the five and separate supply of blood to the epiphyses through the articular arteries, minimize the danger that the process will extend into the joints. This is fortunate, as involvement of the joints would probably necessitate amputation. EXCISIONS. Excisions may be divided into excisions of bones and excisions of joints. Bones are usually excised for ununited fracture and malignant growth, and joints for disease and injury and for the results of disease and injury. Excision of a bone implies either removal of a portion or of the whole bone. The injuries in which excision of a joint may be demanded are fractures extending into joints, especially if compound; gunshot wounds of the joint or of the articular ends of the bones entering into the joint ; and compound dislocations. The disease requiring exci- sion is usually tubercular in character. The operation is performed to shorten the length of time necessary for recovery, thereby shortening the convalescence of the patient to a few weeks instead of allowing the disease to exist for months or years with an uncertain result. Where the patient is becoming weaker as a result of pain and persistence of the disease, the operation is performed to save life. One of the results of disease or injury to relieve which excision is performed is ankylosis of the joint in a bad position. All of the diseased (issue should be removed so that a good result will be assured. In the upper extremity the best result is obtained by preserving mobility through the formation of a false joint. In the lower extremity ankylosis is more desirable than a false joint, as the latter would not give certain support to the superimposed weight. Conditions for which excisions are done in early life require amputation later in life, especially if the disease involves a large joint. In excision of the clavicle an incision is carried along the whole length of the bone, from its sternal to its acromial end. The incision should be carried down to the bone, and will sever skin, superficial fascia, twigs from the acromio- thoracic and supra-scapular arteries, jugulo-cephalic vein when present, descending branches of the cervical plexus, and the platysma myoides muscle. The perios- teum should be divided the whole length of the bone, and stripped from it, first OF THE I'PPEH EXTREMITY. 261 below and then above. I" stripping oil' the periosteum sever the attachments of the sterno-niiistoitl, pcctoralis major, trape/ius, and deltoid muscles, and the attach- ment of the .interior Inver of the costo-coracoid membrane. Next cut through the ligaments of the acromio-clavicular articulation, superior and inferior acromio- clavieular ligaments, ami the interarticular fibro-cartilage, when the acrmnial end of the bone should he raised and the structures attached to its under surface divided namely, the coraco-clavicular ligament, the subclavins muscle with the posterior layer of the costo-coracoid membrane, and the costo-clavicular (rhomboid) ligament. Next detach the bone from the opposite clavicle and sternum by divid- ing the interclavicular ligament, the anterior and posterior sterno-clavicular ligaments, and the interarticular fibro-cartilage. In separating the clavicle from the underlying structures care must be taken to avoid injuring the subclavian vessels and brachial plexus. In sareomatous tumors of the clavicle there will be found many additional vessels, which make the excision more difficult. If the subelavius muscle remain intact, it may be taken as a guide to the subclavian vessels which lie beneath it. Excision of the shoulder-joint is required for disease of the joint, caries of the head of the humerus, and disease of the cartilage. As the glenoid cavity quickly recovers after the head of the bone is excised, the glenoid fossa need not be removed. Excision may also be necessary in the treatment of injuries such as compound fracture and gunshot wounds ; and sometimes the results of injury or disease require excision of the head of the humerus. Ankylosis of this joint seldom demands excision, because the weight of the arm causes fixation in the best position, with the arm at the side, and the mobility of the scapula largely compensates for fixation in the shoulder-joint, and the utility of the limb after excision may not be any greater than after the occurrence of ankylosis. Excision of the shoulder. Tn excision of the head of the humeniB an incision is carried from the acromion process for about five inches down the arm in the line of the humerus. The incision should be made down to the bone, dividing in its course the skin, superficial fascia, twigs from the acromio-thoracie, anterior and pos- terior circumflex vessels, acromial branches of the cervical plexus of nerves, the deep fascia, the fibers of the deltoid muscle, and the trunk of the anterior circumflex artery and vein. The capsular ligament, is opened and the supra-spinatus, infra- spinatus, and teres minor muscles severed from their attachment to the greater tuberosity, and the subscapularis from the lesser tuberosity. These muscles should be detached close to their insertions into the tuberosities. The long head of the biceps must be dissected from its groove and pushed to one side. The coraco- humeral and capsular ligaments are then divided and the head of the humerus 2f>-2 SfJiGICAL ANATOMY. protruded from the glenoid cavity by carrying the arm in front of the body ami pushing it upward. The diseased portion of the bone can then be removed with- out injury to the posterior circumflex vessels and circumflex nerve and the struc- tures in the axilla. At times it may be necessary to detach the head of the bone from the shaft while it remains in the glenoid cavity. In such eases a broad strip of metal or horn should be passed between the neck of the bone and the axillary structures, in order to prevent injury to the latter. Excision in the continuity of the humerus. In excising a portion of the shaft of the liumerus the incision should be made on the outer aspect of the arm, in the sulcus between the biceps in front and the triceps behind. The skin, superficial fascia, twigs of the upper and lower cutaneous branches of the circumHex nerve, twigs from the anterior and posterior circumflex and superior profunda vessels, the deep fascia, and the periosteum will be severed. The cephalic vein is avoided. The incision should be made as long as necessary, but in carrying it downward, care should be taken to keep close to the outer border of the biceps. In the lower part of the arm it is necessary to avoid the musculo-spiral nerve, which lies between the brachialis anticus and supinator longus muscles. The periosteum should be separated from the bone, and as much as necessary of the humerus removed. There will be but little bleeding. Excision of the elbow-joint is performed for disease of that joint, as tuber- cular arthritis ; injury, as compound dislocation, compound and comminuted fractures ; and the results of disease, as ankylosis in a bad position. Ankylosis of this joint causes considerable disability ; therefore, in treating disease of the joint it is most important to preserve its mobility. Excision of the elbow. With the forearm pronated and slightly flexed, a longitudinal incision about four inches in length is carried over the joint, the middle of the incision being directly over the olecranon process of the ulna. The incision severs the skin, superficial fascia, twigs of the inferior external cutaneous branch of the musculo-spiral nerve, twigs of the lesser internal cutaneous nerve, branches of the inferior profunda, anastomotica magna, interosseous and posterior ulnar recur- rent vessels, and the deep fascia. This exposes the tendon of the triceps, which should be split longitudinally down to the bone. The outer half of the triceps, its aponeurotic expansion, and the anconeus muscle should then be carefully pushed to one side. The internal part of the triceps should next be lifted. In doing this care must be taken not to injure the ulnar nerve, which lies in the groove between the internal condyle of the humerus and the olecranon. The nerve is here covered by a dense membrane, which should be incised, when the nerve can be pulled to one side. Now remove the olecranon with the bone forceps. The internal and external lateral ligaments can then be severed, and the ends of EXCISIONS OF THE UPPER EXTIIKMITY. 263 the bones protruded through the wound by sharply flexing the forearm and separating the periosteum from (lie bones with the soft parts attached. A spatula, may no\v he passed between the anterior surfaces of the hones and the struetures in front of the elhow-joint, and a.s much hone removed as is necessary. ]f )><>>- slide, it is advisalde to remove only the articulating surface of the humerus, ihe (decranon process as low as the coronoid process, and the head and neck of the radius ahove the tuhercle. This will allow the hrachialis anticus and biceps muscles to remain intact. After this operation for disease ankylosis is likely to occur, consequently the amount of hone removed must not he too small, and passive motion should he practised after ten days. After excision for injury a flail-like joint is a result more likely than ankylosis, and the part must he kept steady hy a splint, which should have a hinge at the clhow so that passive motion may he practised without laterally moving the joint. Passive motion should at first consist merely of a change in the position of the forearm, which should lie flexed during the day and extended at night. Later, the movements may he more frequently and freely performed, and Stipulation and pronation may he practised. Excision of the bones of the forearm. In excising the ulna, or a portion thereof, the incision should be carried along the posterior or subcutaneous border of the bone, between the extensor carpi ulnaris and flexor carpi ulnaris. The skin, superficial fascia, a few small vessels and nerves, and generally the posterior branch of the internal cutaneous nerve will be severed. After incising the deep fascia, the periosteum is divided and separated from the bone as far as necessary, carrying with it the soft parts. The interosseous membrane, is incised along the radial side of the bone. The bone can then be divided with bone forceps or with a metacarpal or chain saw, and removed. In excision of the radius, or a part of it, the incision should be made along the outer side of the bone, between the supinator longus and the extensor carpi radialis longior, taking advantage of the position of the radial nerve in locating the interval between the tendons of the respective muscles. The skin, the superficial fascia, a few small vessels and nerves, the- deep fascia, and the periosteum will be severed. The periosteum is separated from the radius as far as necessary ; the insertion of the supinator longus at the lower end of the bone and that of the pronator radii teres at the middle of the bone being detached with the periosteum. The interosseous membrane, and at times the orbicular ligament, must be detached from the ulnar side of the bone, which can then be removed either with a powerful pair of bone forceps or the chain saw. Excision of the radio-carpal joint. Excision of the wrist-joint is usually per- formed for disease, such as caries, and rarely for injury, as compound fracture, 2i\-\ SURGICAL A \ATUMY. compound dislocation, or gunshot wounds. It' an excision is performed for disc it is usually necessary to remove the end- of the radius and ulna, the carpus, and the l>ases of the nu'tacarpal hones, so as to include all diseased hone. Total excision of this joint, including the carpal hones and the hases of the nietaearpal hones, is seldom necessary. !>y placing the part at rest and improving the general health the disease may usually he arrested without operation and a useful hand preserved. Passive' motion of the lingers must he practised early to obtain the best possible result. In excising the wrist-joint two incisions should be made: one along the radius, extending from a point about two inches above the styloid process of the radius to the middle of the metacarpal bone of the thumb; and another along the ulna, from a point about two inches above the styloid process of the ulna to the middle of the metacarpal bone of the little finger. The radial incision severs the skin and superficial fascia, twigs of the musculo-eutancous and radial nerves, small branches of the radial artery, some superficial veins, and the dee]) fascia. (I real care must be taken not to injure the radial artery, which lies in front of the lower end of the radius and upon the external lateral ligament of the wrist-joint. The radial incision passes between (lie tendons of the extensor ossis metacarpi pollicis and extensor primi internodii pollicis. The nlnar incision divides the skin and superficial fascia, twigs of the internal cutaneous nerve, small cutaneous branches of the ulnar artery, some superficial veins, and the deep fascia. The tendons and soft parts are to be carefully dissected from the posterior surface of the carpus, radius, and ulna. The radial artery is now displaced, and held aside with a retractor. A sharp-pointed bistoury is entered on each side in front of the radius and ulna, and the soft parts separated from both bones by currying the knife downward. As the knife passes over the carpus it will come in contact with the pisiform bone, which lies on the ulnar side of the forearm ; this bone should be removed with a pair of bone force] is. The lateral ligaments are next divided, the ulna and radius drawn out on their respective sides, and the articulating surfaces removed. A blunt-pointed bistoury is used to divide the dorsal ligaments between the two rows of carpal bones, and the upper row is removed with the sequestrum forceps. If necessary, all the bones of the carpus may be removed in this manner. As the curpo-metacarpal articulations, are reached, great care must be observed not to injure the deep palmar arch. In this operation there is but little danger of wounding the radial and ulnar arteries, if the proper amount of care be exercised. In excising a metacarpal bone the incision should be made over the dorsal aspect of the bone. The skin and superficial fascia will be severed, together with branches of the radial and ulnar arteries and superficial veins, branches of the dorsal cutaneous branch of the ulnar nerve over the metacarpal bone of the little and the ring finger, and branches of the radial nerve over the metacarpal bone EXCISIONS OF THE UPPER EXTREMITY. 265 of the middle and the index finger. The deep fascia is cut, and care must be taken to avoid injuring the extensor tendons ; these must be pushed to one side, and the periosteum divided. If the head of the bone is to be removed, the meta- carpo-phalangeal joint must be opened by cutting through one of the lateral expan- sions of the extensor tendon, raising the tendon, and dividing the lateral ligaments and the transverse melacarpal ligament ; the bone is then elevated. The interossc< >ns muscles must be separated from the bone with the periosteum, and the bone freed from all surrounding structures. As much of the metacarpal bone as is diseased can then be removed with the forceps. Care must be taken not to injure the deep palmar arch when removing the structures from the palmar surface of the bone. If the entire bone be removed, the carpo-metacarpal ligaments must be severed. In excision of the metacarpal bone of the thumb the incision should be made on the line between the dorsal and palmar surfaces. Skin, fascia 1 , branches of the radial artery, superficial veins, and branches of the radial nerve will be severed, yet with care the branch of the radial nerve supplying the outer side of the thumb need not be divided. The incision reaches the bone by passing along the palmar side of the tendon of the extensor primi internodii pollicis. The soft structures with the periosteum are separated from the bone on the palmar and dorsal surfaces, and the ligaments of the carpo-metacarpal and metacarpo- phalangeal joints severed. In excising the articulating surfaces of the phalanges the incision should be made over the dorsal aspect of the respective joints at the side of the extensor tendon, and should extend from the proximal side of the joint to the middle of the phalanx to be removed. The incision is made parallel with the extensor tendon, which is pushed to one side as soon as it has been exposed. The extensor tendon is raised, the lateral ligaments are severed, the ends of the bones are elevated, and as much bone as necessary removed with the bone forceps. In excising the last phalanx the incision may be made along the palmar surface of the finger, or around the end of the finger. In the former case the soft parts are stripped from the sides of the bone, and in the latter from the dorsal and palmar aspects. The bone is then grasped with the bone forceps and twisted on its long axis so as to facilitate the division of the two lateral ligaments and of the flexor and extensor tendons. It is better to leave the soft parts in place than to remove part of them with the bone. If the base of the phalanx is not much diseased, it is better not to remove it, on account of the attachment of the tendons. 2C,C, VnuiH'Al. ANATOMY. Development of the Bones of the Upper Extremity. The time <>f union of the various centers of ossification in the bones of the body plays an important part in the diagnosis and treatment of the various fractures which occur. This is especially so when the fracture is located near one of the epiphyseal ends of the bone. The clavicle lias two centers of ossification one for the shaft, and one for the sternal end. Ossification in the shaft begins about the sixth week of fetal life. The clavicle is the first bone in the body to show signs of ossification. About the nineteenth year an epiphysis appears at the sternal end, and subsequently unites with the remainder of the bone. The scapula has seven centers of ossification one for the body, two for the coracoid process, two for the acromion, one for the posterior border, and one for the inferior angle. At birth the body of the scapula is the only part which is ossified. The center for the middle of the coracoid process appears in the first year. The other centers appear in the fifteenth or sixteenth year, when the coracoid process joins the body of the bone. These epipliyses join and unite with 'the body of the bone between the twenty-second and twenty-fifth years. An ununited epiphysis of the acromion may be mistaken for an ununited fracture. The former condition is recognized by the presence of an ununited epiphysis upon the uninjured side also, whereas ununited fracture of the acromion is almost invariably unilateral. The humerus has seven centers of ossification one for the shaft, one for the head, one for the greater tuberosity, one for the capitellum, one for the internal condyle, one for the trochlea, and one for the external condyle, and, generally, one for the lesser tuberosity. These centers appear at different periods, and unite, as a rule, in the reverse order of their appearance. About the fifth year the centers for the head and tuberosities coalesce ; the union of this epiphysis to the shaft does not take place, however, until about the twentieth year. The centers for the external condyle, capitellum, and trochlea coalesce and unite with the shaft in the seventeenth year. The center for the internal condyle forms a separate epiphysis, which joins the shaft during the eighteenth year. From this it can be seen that there may be separation of the upper epiphyses as late as the twentieth year, and of the lower ones as late as the sixteenth to the eighteenth year: In all epiphyseal fractures in young children it is to be remembered that consid- erable shortening may follow, as the bone may fail to increase in length owing to injury to the epiphysis. The radius has three centers of ossification one for the shaft and one for each end. The upper end unites during the seventeenth year, the lower during the nineteenth. ' PLATE LXIX, EisplacEmEntin FracturEnfthE middlEoffhE Davids. Sferno-delda-mastoid. \5ubcl wiu s, Trff/jpzius 3 nit } Rftmitboidei. [Perforates mBJrmi i" \Lafis5ifTJus dorsi. \WeightoMrm \antl Shou/der. Frdcfi/re of Anatomies I Nsck of E cap u la, 268 FI;. \rruRES OF THE UTTER EXTREMITY. The ulna lias three (.'(.'liters one fur (lie shaft and coronoid process, oiu the oleeranon, and one tor the lower (Mid. The lower end unites to the shaft ahout the eighteenth year, and the oleeranon center, although it does not begin ossifica- tion before the eighth, unites to the shaft about the sixteenth year. The carpal bones each have but a single center of ossification, and these uppeur after birth, at different periods. The metacarpal bones have two centers the metacarpal bones of the fingers have a center for the shaft and proximal end, and another for the distal end ; the metacarpal bone of the thumb has a center for the shaft and distal end, and another for the proximal end. These centers are united about the twentieth year. Each phalanx has two centers one for the shaft and distal end, the other for the proximal end. They unite about the twentieth year. FRACTURES. The treatment of fractures aims : (1) To return the parts to their normal relations ; (2) to continuously keep the fragments and their ends steady, this requiring a splint, or other stiff dressing, which extends throughout the length of the fragments and beyond joints moved by muscles attached to the fragments ; (3) to retain the function of joints or tendons in close proximity by passive move- ment practised as soon as union is sufficiently firm. Fracture of the clavicle is very frequent because it holds an exposed position and is the only bony connection between the upper extremity and the trunk. As about one-half of these fractures occur in children under five years of age, green- stick fracture of this bone is common. In this form of fracture there may be little displacement, and the true condition may not be detected until callus forms and a swelling is produced. If a child has fallen and cries constantly, the clavicle should be carefully examined. In comminuted fracture of the clavicle there is danger that the subclavian vein, subclavian artery, or brachial plexus may be injured. These structures are protected by the intervening subclavius muscle and prevertebral fascia, and there- fore this complication is rare. If the vein or the artery be torn, the blood gravi- tates to the axilla through its apex, and the resulting condition is a traumatic aneurysm. If the brachial plexus be injured, there will be motor and sensory disturbances in the upper extremity. Of these three structures the vein is most likely to be injured because of its closer relation to the bone and the thinness of its walls. A traumatic aneurysm of the axilla has been mistaken for an abscess. 270 SURGICAL ANATOMY. Fractures of the claviele generally occur near the outer end of the middle third. The reasons for the greater frequency of fractures in this position are that the hone at this situation is smaller and consequently weaker, and begins to bend forward and derives less support from the muscles and ligaments. The deformity in fracture of the middle third of the clavicle is displacement of the inner frag- ment upward, and of the outer fragment downward and inward. The inner fragment is drawn upward by the sterno-cleido-mastoid. The outer fragment is drawn downward by the weight of the arm and shoulder ; downward and inward by the pectoralis major, the pectoralis minor, and the latissimus dorsi ; inward by the subclavius, trapezius, and rhomboidei muscles. In displacement of the inner fragment upward the action of the sterno-cleido- mastoid is antagonized by the rhomboid ligament, the clavicular portion of the pectoralis major, and the inner fibers of the subclavius muscle. The clavicular fibers of the trapezius antagonize the downward displacement of the outer fragment, and the serratus magnus its inward displacement. Fractures of the scapula are uncommon, only one per cent, of all fractures occurring in this bone. This is due to the free mobility of the bone and to its pro- tection by overlying muscles. Fractures may involve any portion of the bone. They are usually produced by direct violence, but may be caused by muscular action or by indirect violence, as a fall upon the arm. Fractures of the body of the scapula not involving the spine of the bone are detected with difficulty, because of the thickness of the overlying muscles ; whereas those of the spine and acro- mion are readily detected because of their superficial position. Fracture of the anatomic neck of the scapula, which is external to the coracoid process, is so rare that but one case has been recorded. This condition simulates subglenoid dislo- cation, in that the arm is lengthened as the arm and glenoid cavity drop down- ward. It is readily differentiated from subglenoid dislocation by raising the arm, when crepitus may perhaps be elicited. As soon as support of the arm is with- drawn, the arm again lengthens. In fracture of the anatomic neck of the scapula, injury of or pressure upon the axillary vessels and brachial plexus is almost certain to occur. In fracture of the surgical neck of the scapula the glenoid cavity and arm are prevented from dropping downward by the attachment of the coracoid process to the clavicle by the coraco-acromial ligament, unless the latter is torn. Fractures of the spine and acromion are detected by tracing these subcutaneous processes with the finger. Most of the recorded fractures of the acromion are supposed to have been ununited epiphyses. Fracture of the coracoid process is produced by indirect violence applied to the arm, thereby forcing the scapula upward and driving the coracoid process against the clavicle. Fractures of the humerus comprise about eight per cent, of all fractures. PLATE LXX. * .. IT i ' ^ ^ n. 1 272 FRACTURES OF THE I '/'/'Hi; I^TIiKMITY. 273 They nisiy occur through any of tlic various divisions of the bone, as the ana- tomic neck, the tuberosities, the surgical neck, the middle third of the shaft, the external or internal condylc, the shaft immediately almve the condyles and between the condyles. Separation of the epiphysis may occur at either extremity of tile bone. In fracture of the ii
  • i> I fracture the deformity is widening of the joint and inward displacement of the olecranon. After fracture of the condyles there is not infrequently seen an inward deflec- tion of the bones of the forearm at the elbow. In the normal condition, with the forearm extended and supinated, the radius and ulna form an obtuse angle with the humerus, so that when the arm lies at the side of the body, the hand projects away from the median line of the body. By an upward displacement of the inner condyle, or a downward of the outer, this angle may be lost, and the so- called "gun-stock deformity," described by Allis, is then produced. In fractures of the upper end of the humerus i. e., of the surgical or ana- tomic neck the circumflex nerve may be injured, in fracture of the shaft the musculo-spiral nerve, and in fracture of the internal condyle the ulnar nerve. When the symptoms of nerve injury appear shortly after or at the time of the occurrence of the fracture, they are caused by laceration or pressure by a frag- ment ; but if they develop late, they are the result of pressure by callus. The character of the symptoms presented depends upon the amount of pressure exerted. Moderate pressure irritates the nerve, and causes tingling and pain in the area of distribution of its sensory branches, and spasm of the muscles supplied by its motor branches. Greater pressure causes anesthesia and trophic disturbance in the area supplied by its sensory fibers, and paralysis and atrophy of the muscles supplied by its motor branches. In fracture the circumflex nerve is rarely injured ; injury to the musculo-spiral and ulnar nerves occasionally occurs. AVhen the circumflex nerve is involved, there is pain or partial or complete anesthesia over the deltoid and upper part of the triceps, and spasm or paralysis of the deltoid and teres minor. If the musculo-spiral nerve be affected, there is pain or more or less anesthesia in the back and outer part of the arm and forearm, and spasm or paralysis of the muscles which the nerve supplies. These muscles are the trice] is, anconeus, supinator longus, extensor carpi radialis longior, extensor carpi radial is PLATE LXXI. 276 FRArrri!l-:s OF THE T/'/V-.V,' KXTHKM1TY. Ill brcvior, extensor eonimuiiis digitorum, extensor minimi digiti, extensor carpi uliiiiris. siqiinator brevis, extensor ossis metacarpi pollicis. extensor longtis pollicis. extensor lirevis pollicis, and extensor indieis. Paralysis of the triee|is is unlikely because of the high origin of the branches to that muscle. The condition which results from paralysis of the musculo-spiral nerve is known as "wrist-drop." The hand is pronated and the wrist and fingers Hexed. Loss of opposition from the extensors, which steady the fingers during flexion, causes loss of power in grasping objects. When the ulnar nerve is affected, there is pain or anesthesia in the ulnar side of the forearm and hand, in the little finger and ulnar half of the ring finger, and there is spasm or paralysis of the flexor carpi ulnaris, ulnar side of the flexor prothndus digitorum, the palmaris brevis, short muscles of the little finger, two ulnar lumbrieales, inlerossei, adductor pollieis, and inner head of the flexor brevis pollicis. Paralysis of the interossei unbalances t lie state of equilibrium existing between the flexors and extensors, and as a result the first phalanges are extended and the distal phalanges partially flexed. This produces a " clnwcd hand," or main en griffe." Power of flexion of the little and ring fingers is lost, and power of movement of the thumb is much diminished. Fracture of the radius. The radius usually sustains fracture about the lower one-third, where it occurs much more frequently than in the middle or upper one-third. In fracture of the head or neck of the radius the lower fragment is carried upward and forward by the biceps, which is inserted into the tuberosity. Many surgeons and anatomists claim that it is impossible to have a fracture of the neck of the radius, unless it be complicated by some other fracture or a dislocation. The author has proved by X-ray photography and subsequent operation that simple fracture of the neck of the radius does occur. Fracture of the radius may occur between the insertion of the biceps and that of the pronator radii teres, although such a fracture is very rare. The upper frag- ment would be strongly supinated by the action of the biceps and the supinator brevis, and the lower would be pronated and approximated toward the ulna by the pronator radii teres and the pronator quadratus. As the two strong supinators, the biceps and supinator brevis, would have no influence over the lower fragment, the supinator loiigus could not counterbalance the action of the pronator radii teres and pronator quadratus. Fracture of the lower end of the radius (Colics' fracture) is the most frequent of this bone. The deformity is chiefly caused by the breaking force, which pushes the lower fragment backward and upward, making it override the upper fragment, which is forced downward and forward. The alteration of contour thus effected is 278 SI'KGICAL ANATOMY. known as the " silver-fork deformity." The displacement of the fragments is partly due to the extensors of the wrist and fingers. The hand is carried to the radial side by the supinator longus, the extensores carpi radialis longior and liivvior, and the extensors of the thumb, they being rendered tense by the displace- ment of the lower fragment. The ulna may be fractured at any point. As a rule, fracture of the ulna is caused by direct violence, and for this reason there is no uniform displacement of the fragments, as this must vary with the angle of impact at which the breaking force operates. If there be any usual direction for displacement of the fragments, it is probable that the lower fragment would be drawn toward the radius by the action of the pronator quadratus. The upper fragment can only be displaced to any extent backward or forward, because of its connection with the humerus at the elbow-joint. Fracture of the coronoid process is exceedingly rare. If it should occur, the process will probably be drawn upward by the brachialis anticus, which is attached to its base. As the coronoid process forms the anterior wall of the greater sigmoid cavity of the ulna, this fracture is usually associated with a backward dislocation of either this bone alone or of both the radius and ulna. In fracture of the olecranon process the displacement of the upper fragment is always upward, and is determined by the action of the triceps. The extent of the displacement depends upon the degree of the breaking force and upon the extent of the rupture of the ligaments which surround the elbow-joint. If the forearm lie markedly flexed at the time the fracture occurs, it is probable that the ulna will be dislocated forward by the action of the biceps and the brachialis anticus. Fracture of both bones of the forearm most commonly occurs below the middle, where they are least protected by muscles. When the fracture is com- plete, the deformity is usually very slight. In incomplete, or " green-stick," fracture the deformity depends upon the amount of bending of the bones. Occa- sionally there is sufficient displacement to produce an angular deformity. Simple fractures of the carpus are rare. When they occur, there is but little, if any, displacement of the fragments, owing to the firm ligamentous con- nections existing between the bones. In fractures of the metacarpal bones there is but little displacement, on account of the attachments of the ligaments, and the position of the flexor and extensor tendons and interossei muscles ; all of which tend to hold the frag- ments in place. If there be any displacement, the proximal end of the distal fragment will project on the back of the hand, resulting in shortening produced by the fracturing force and by the action of the flexors and extensors. , AMITTATIOXS. :27',) The displacement in fractures of the phalanges is never very great. AY hen. present it is usually transverse ami duo to the direction of the breaking force. If the line of fracture he oblique, there may be some overlapping. AMPUTATIONS. In amputations the following considerations should be borne in mind : (1) Save the patient's life. (2) Obtain a useful stump. (.">) Secure a suilicieiit and healthy cutaneous covering for the end of the stump, with little redundant muscular tissue therein. All tendons are cut even with the end of the bone or bones and not drawn out, as it is desirable that they adhere to the cica- tricial tissue and add to the mobility of the stump. Large nerves should be gently drawn out and severed on a level with the end of the bone, so that they will retract within their sheaths and the bulbs, or false neuromata, which form upon their cut ends will not be included in the cicatrix and cause a painful stump. (4) The flaps should usually be made by dissection, and be of sufficient length to avoid the formation of a conic stump and allow free mobility of the stump. (5) The resulting scar should not be in the middle of the end of the stump, because pressure upon the scar causes pain, and usefulness of the member will be thereby lessened. In the thigh and leg it should be situated posteriorly ; this result is secured by making a long anterior and a short posterior flap. In this location the greater contraction of the muscles divided upon the dorsal aspect tends to retract the scar still further posteriorly. At the wrist or ankle or in the foot a palmar or plantar flap is desirable, as it is best adapted fur bearing pressure. (6) It is well to save as much of the limb as can be retained with safety and future utility, as the danger of the operation increases with the length of the limb removed. (7) A deformed and ugly living appendage is likely to be of greater utility than the best artificial one. After the operation is completed, the vessels are ligatured, the wound is cleansed, drainage is established, and the flaps are held in apposition by sutures. In amputation of the phalanges : (1) Save as much as possible, especially of the thumb, in order that it may be apposed to the remaining digits. (2) Do not interfere with the palm, large scars of which may be painful and develop epitheli- oma. (3) Do not remove the heads of the metacarpal bones or divide the trans- verse metacarpal ligament, as the hand would thus be weakened. (4) The full breadth of the hand should be preserved. Amputations are performed at one of two points through the continuity of the bones of the limbs or between their contiguous extremities. SURGICAL ANATOMY. < >f tin 1 various methods of amputation which have lieen adopted, only those wliich have proven most satisfactory to the autlior will he described. The methods of amputation adopted hy the autlior include the- following: The circular, the modified circular, the flap, Teale's. Speiice's, Lister's, and the oval. The method adapted to any operation depends upon the position, conforma- tion, and anatomy of the part to he amputated and upon the condition of the tissues in that locality. No one method is expedient in all locations; for while in one place the circular method gives good results, better results are obtained in other situations by one of the Hap methods. The circular method. In the original circular method the hone and all other tissues were divided at the same level. At present in this method three incisions are made. The first incision divides skin and superficial fascia and separates the superficial from the deep fascijc ; in this manner a cuff of skin and superficial fascia equal in length to one-half of the diameter of the limb is dissected up and everted and rolled up as high as possible. The second incision divides the deep fascia and underlying tissues at the level of the attachment of the cuff of skin and superficial fascia ; and the third divides the bone as high as possible while the soft tissues are retracted. The resulting wound is in the form of a pit with the sawed end of bone at the bottom; in this way the danger of a resulting conic stump is eliminated. The advantages of the circular method are that in a fleshy limb it avoids a redundance of useless muscular tissue in the stump. All the vessels are divided transversely, contract and retract well, while unnecessary hemor- rhage is avoided. The surface of the wound is smaller than in other methods; for this reason union occurs more promptly and the resulting cicatrix is smaller. The disadvantages are that the cicatrix extends across the middle of the end of tlie stump and is adherent to the bone. This is likely to cause a tender stum}), and in the lower extremity will be a great disadvantage, as the patient can not bear any weight upon the stump. As the corners of the stump wound are always puckered, the edges of skin do not lie in apposition and union does not, therefore, occur quickly. The modified circular method. Tn this method two semilunar incisions are made through skin and superficial fascia, dissecting up two short flaps equal in length to one-quarter of the diameter of the limb. These flaps are then everted and a short cuff of skin and superficial fascia rolled up as in the circular method. Then the muscles and deep fascia are divided at the level of the retracted skin on the anterior surface of the limb, and on the posterior surface of the limb at a distance from the retracted skin equal to one-fourth of the diameter of the limb. The soft parts are retracted from the bone, which is sawed at the highest possible Icvd. This method differs 1'rom the circular method only in having two small Haps of skin and superficial fascia and a short sleeve of skin and superficial fascia instead of a long sleeve of skin and superficial fascia to cover the stum]). The circular method is well adapted to amputations of the arm, where the part does not taper from above downward. Where the part tapers, as in a muscular fore- arm or calf of the leg, the modified circular is best. Both the circular and modified circular methods are well adapted to amputation of the arm and fore- arm where a seal 1 across the middle of the end of the stump is not of serious dis- advantage. These two methods give the longot possible stump. The flap method. The flaps, are made by cutting from without inward (dis- sect ion), or from within outward (transfixion). The flap furthest from the main vessel is usually made first. The advantages of this method are the following: It is more easily and readily performed than the circular method ; it gives a thicker cushion for the stump, as the muscular tissue of the flaps disappears while some fibrous tissue of the muscles remains. The disadvantages are the following: Many of the blood-vessels of the part are divided obliquely and do not contract and retract well, and in ligaturing them it is necessary to exercise more care in order that the vessels maybe tied entirely above where they have been severed ; on account of the irregular contraction of the various muscles divided, the stump may be irregular ; the surface of the wound is larger than in the circular method, and very thick muscular flaps are in themselves a disadvantage. The transfixion method of making flaps is more rapid than the method by dissection, but the skin is divided in an uneven line and the flaps are likely to be too thick. The first objection can be avoided by dividing the skin and superficial fascia by dissection and then dividing the muscles, deep fascia, vessels, and nerves by transfixion. The dissection method of making flaps requires more time, but the skin is divided in the manner desired and the flaps may be made of proper thickness. When there are ulcers, sinuses, or malignant growths the flap may be shaped as circumstances demand. Teale's method consists of the formation of a long and a short rectangular flap. The breadth of each flap is equal to one-half of the circumference of the limb. The length of the anterior flap is equal to one-half of the circumference of the iimb, and that of the short flap to one-fourth of the length of the long flap. As the long flap covers the end of the bone it should not contain the large vessels, and for this reason it is taken from the front of the leg in amputations through the tibia and fibula, in the forearm from the dorsal surface, and just above the knee the long flap should be taken from the antero-external surface. This method is used above the ankle, immediately above the knee, and sometimes in the forearm. 282 SUlKiK'M. ANATOMY. The advantages of this method are the following : The bone is well covered, the wound is in a position to allow free drainage, the cicatrix is not upon the end of the stump and hence is not likely to cause pain from pivssmv produced by an artificial limb. The chief disadvantages are as follows: The great length of one of the Haps necessitates a very high amputation; the operation requires much time, as the flaps must be accurately outlined; the doubling of the long flap by pressure upon the vessels may impair its nutrition; in malignant disease recur- rence often takes place in one of the flaps on account of its length, which makes it more difficult to avoid including involved tissue; in injury of the soft parts an unnecessarily high amputation is required to secure good flaps; if the flaps fail to unite by first intention, the sagging of the long flap prolongs recovery by increas- ing the space to be filled by granulation tissue ; the area of the wound is extensive, and too much bone is sacrificed. In Spence's method a long anterior and a short posterior flap are made. The long flap is not so long, and the short flap is longer than in Teale's method, and the tissues are cut obliquely from without inward to the bone. The soft parts are retracted from the bone, which is sawed two inches above the bases of the flaps. This method is best adapted to the lower third of the thigh and to a very muscular limb. The advantages are : That the long flap is not doubled upon itself; that if union by first intention does not occur, there is not much tendency to separation of the flaps and the wound is more manageable ; that a good covering is afforded for the stump, and that the cicatrix is not upon the center of the end of the stump. In Lister's method a long anterior flap, equal in length to two-thirds of the diameter of the limb, and a short posterior flap, equal in length to one-half of that of the anterior flap, are made. The flaps are procured by dissection, and are chiefly composed of skin and superficial fascia although some deep fascia and muscular tissue may be included in the base of the anterior flap so that its blood supply may be as plentiful as possible. The flaps are raised and the remainder of the soft tissues divided at the level of the bases of the flaps. The soft tissues are forcibly retracted for a distance equal to one-fourth of the diameter of the limb, and the bone divided as high as possible. If retraction of the soft parts be impos- sible, it will be necessary to carry a lateral incision upward from the points of junction of the two flaps, so that the bone may be divided at a sufficiently high level. In the thigh it is necessary to retract the soft parts a distance equal to one-half the diameter of the limb before sawing the bone. In the lower part of the forearm and leg the anterior flap must be equal in length to the diameter of the limb, and the posterior flap in length equal to one-half the diameter of the limb. Such modifications are required in these locations because the bones occupy a large part of the diameter of the limb. AMPUTATIONS OF THE UPPER EXTREMITY. 283 The oval method is similar to the circular, except that it has a longitudinal incision at one side. When this cut is very long, the incision is said to be racket- shaped. This method is best adapted to amputation of the fingers and toes. Amputation of the phalanges. Phalanges are usually amputated because of injury, or the results of whitlow or felon. The base of the phalanx may not be affected by necrosis, as the periosteum is protected by the insertions of the flexor and extensor tendons. In removing a portion of the finger through the continuity of the phalanx, two oval flaps one anterior and one posterior are made. The palmar flap is the longer, in order to preserve as much as possible acute tactile sense for the end of the stump. The structures divided will depend upon the distance of the incision from the metacarpal bone and the finger amputated. In these amputations the skin and superficial fascia, with the collateral digital arteries, which receive blood from both the radial and ulnar arteries, will be divided. The nerves severed in the amputations are, in the case of the little finger, branches of the ulnar nerve ; of the ring finger, branches of the ulnar, median, and radial nerves ; of the middle and index fingers and thumb, branches of the median and radial nerves. In amputation through the last phalanx no tendons will be divided. In amputations of the distal phalanges of the fingers, the tendons of the extensor communis digitorum and flexor profundus digitorum are divided. When ampu- tating the second phalanx of the fingers, the tendons of the flexor sublimis and flexor profundus digitorum and extensor communis digitorum are severed. In amputations of the first phalanx of the thumb, the tendons of the extensor primi internodii pollicis, extensor secundi internodii pollicis, flexor longus pollicis, and of the short muscles of the thumb are divided. In amputating the second phalanx of the thumb, the tendons of the flexor longus pollicis and extensor secundi internodii pollicis are severed ; in amputating the proximal phalanx of the fingers, the tendons of the superficial arid deep flexors, the common extensor, the interosseous and lumbrical tendons are divided. The line of the interphalangeal joints is opposite the transverse furrows on the palmar surface of the fingers, and immediately to the proximal side of the ridge on the base of the respective phalanges. In disarticulating the metacarpo-phalangeal joints the preferable incision is one commencing over the distal end of the dorsal surface of the metacarpal bone, carried around both sides of the finger and through the crease of the palmar surface of the proximal phalanx. The structures divided are the tendons of the common extensor, flexor sublimis digitorum, flexor profundus digitorum. iriter- osseous and lumbrical tendons, the lateral and anterior metacarpo-phalangeal ligaments, and the collateral digital vessels and nerves. iis4 SURGICAL .I.V.I TOMY. Disarticulation of the four metacarpal bones of the fingers. In disarticu- lating these Indies from the cari>ns by transfixion tlit. 1 point of tin- knife is inserted at the junction of the tnetacarpal lione of the little tinker \vitli tin- earpus, pushed through the soft parts of the palm of the hand close to the hones, and brought out in the fleshy tissue between tin- thumb and index finger. The knife is then carried downward and forward (away from the bones), cutting through the flexor brevis minimi digiti, opponens minimi digit i, abductor minimi digiti, adductor pollicis, palmaris brevis and lumbricales muscles, the tendons of the flexor sub- limis digitorum and flexor profundus digitorum, tin- profunda branch of the ulnar artery and nerve, the deep palmar arch, the digital arteries and nerves, the deep and superficial palmar fascia', and the skin. The hand is then pronated, and a semicircular incision, with the convexity downward, carried across the dorsal surface joining the two ends of the palmar incision. The dorsal incision divides the skin and superficial fascia, some of the radicles of the radial, anterior and posterior ulnar veins, branches of the radial and ulnar nerves, the deep fascia, the tendons of the extensor carpi nlnaris, extensor minimi digiti, extensor communis digitorum, extensor indicis. the synovial sheaths of the tendons, the dorsal inter- osseous arteries, and the dorsalis indicis. These two flaps are then dissected upward until the articulation is reached. The metacarpal bones should be disar- ticulated, beginning on the palmar surface. The capsular, palmar, dorsal, and interosseous ligaments are severed and the hand removed. The sheaths of the flexor and extensor tendons should be sutured, there being less liability of infection traveling along them than if they were allowed to remain open. Amputation of the thumb at the carpo-metacarpal articulation. In amputating the thumb at the carpo-metacarpal articulation the incision should be made along the junction of the dorsal and palmar integument and around the base of the proximal phalanx. The proximal extremity of the incision commences over the articulation of the metacarpal bone with the carpus, about one inch from the styloid process of the radius. In this amputation care must be exercised to avoid injuring the radial artery, which is closely related to the base of the metaearpal bone of the thumb. The following structures are divided : The skin, superficial and deep fascia 1 , branches of the radial and median nerves, the dorsales pollicis and princeps pollicis arteries, the tendon of the flexor longus pollicis, the short muscles of the thumb, the abductor indicis (first dorsal interosseous), and the capsular ligament. A lateral, rather than a dorsal, incision may also be made in removing the metacarpal bone of the little finger. Disarticulation of the radio-carpal or wrist-joint. That the movements of pronation and supination of the stump may be retained, the wrist, rather than a higher position on the arm, is selected for the amputation. This operation is PLATE LXXII. MedianN. Flexor carpi Radia/is M. Flexor Lnnjjus pal HcisM. Radial A. RadialN. Palmar/s /nngus Tendon FlexorSublim/sdigirorum M. UlnarA. \UlnarN. , Flexor prof undus d /giro rum M. Supinaf-arlongusTent/on /onginr Tendon Extensor carpi rdd/a//s AreworAt. Anterior inferosseous/V. Anterior interosseousA. /nrerosseoi/BMembrj/ie Extensor carpi ulnans M. Extensor languspo//ir./sM. Extensor min/m/dij?/fiM. Posterior interosseas ft. Posterior inferasseus A . Extensor 055/5 mef-aarpi po///cis M. TRANSVERSE SECTION OF FOREARM JUST BELOW MIDDLE. 286 AMPUTATIONS OF THE UPPER EXTREMITY. 287 usually |>(Tl'<>niir lie ligated are the radial and ulnar. The radial will be found on the radial side of the forearm, on the external lateral ligament of the wrist-joint just below the styloid process of the radius. The ulnar artery w r ill be found on the anterior aspect of the forearm, just internal to the tendon of the flexor carpi ulnaris, and external to the tendons of the flexor sublimis digitorum. Amputation at the middle of the forearm. This operation is generally per- formed by the antero-posterior flap method. The anterior incision is semilunar, with its convexity downward, passes from one border of the forearm to the other, and divides skin, superficial fascia, the radial, median, and anterior ulnar veins, the anterior branch of the musculo-cutaneous nerve, the anterior branch of the internal cutaneous nerve, cutaneous branches of the radial and ulnar arteries, the deep fascia, the flexor carpi ulnaris, the ulnar vessels and nerve, the flexor sublimis digitorum, the palmaris longus, the flexor carpi radialis, the median nerv^3 and artery, the flexor profundus digitorum, flexor longus pollicis, the radial vessels and nerve, and the supmator longus. The posterior incision divides the skin, the superficial fascia, the posterior ulnar vein, the posterior branch of the internal cutaneous nerve, the inferior 288 SURGICAL AXAToMY. external cutaneous branch of the musculo-spiral nerve, the posterior branch of the musculo-cutaneous nerve, cutaneous branches of tlie radial and ulimr arteries, the deep fascia, the extensor carpi ulnaris. extensor mininii digiti, extensor eoiuniunis digitorum. extensores carpi radialis longior ami bivvinr. extensores primi and M'cimdi internodii pollieis, extensor ossis rnetacarpi pollieis, and the posterior interosseous vessels ami nerve. The interosseous membrane and the anterioi 1 interosseous vessels and nerve are divided. The 1 bones should then lie sawed, and the main vessels Heated. These will be the radial artery, which will be found between the pronator radii teres and snpinator longns muscles; the ulnar artery, between the flexor carpi ulnaris, the flexoivs snblimis and profundus digitorum ; the anterior interosseous artery, on the anterior surface of the inter- osseous membrane; and the posterior interosseous artery, between the superficial and deep extensors. Amputation of the elbow-joint. The most satisfactory method for per- forming this operation is by transfixion. The knife should be introduced about three-quarters of an inch below the internal condyle of the hurnerus, with the forearm supinated and slightly flexed. The object in flexing the forearm is to relax the anterior ligament so that it can be transfixed when the knife passes over the joint. The point of the knife should emerge from the radial side of the forearm the same distance below the external condyle. The knife should then be carried down the forearm for about four inches and brought abruptly to the surface. The structures severed will be the anterior ligament of the joint, the brachialis anticus, the snpinator brevis, the posterior interosseous nerve, the tendon of tlie biceps, the extensor carpi radialis lougior, the supinator longns, the flexor profundus digitorum, flexor longus pollieis, the common interoaseous or anterior and posterior interosseous vessels, the anterior interosseous nerve, the median artery and nerve, the radial vessels and nerve, the ulnar vessels and nerve, the posterior ulnar recurrent artery, the superficial flexors, the deep fascia, the superficial fascia, the radial, anterior and posterior ulnar and median veins, the anterior and posterior branches of the musculo-cutaneous nerve, the anterior branch of the internal cutaneous nerve, and skin. A posterior incision should then be made directly across the back of the forearm, over the base of the olecranon, so as to connect the two ends of the anterior incision when a flap of skin and superficial fascia is raised as high as the tip of the olecranon. This incision divides the skin, superficial fascia, the inferior external cutaneous branch of the musculo-spiral and the posterior branch of the internal cutaneous nerve. The knife should then be passed between the head of the radius and the humerus, and then across the front of the joint between the coronoid process of the ulna and the humerus, severing the internal and external lateral ligaments and part 1!) PLATE LXXIII. Cepha/icV. Brae hi a/i s Anf/cusM. B/ceps m. Superficial fascia Muscu/o cutaneous /V. Deep fascia Med/an/V. fx/ernal /nfermuscu/ar 5ept-um. Outer Head of Triceps M. Muscu/vspfra/M Superior ProfuntiA W$^$^J8<1? \T VvV-v" v'- '- -"',"^W--C* >*f~ \ ^g5^|g|l" \\. \v- .-..;'Sfc-v. --- Long Head of Triceps M. Vena comes Brachial A. Internal Cutaneous N. Bas/t/cV. U/narH. /nferiarProfundaA. fafema/ /nfermuscu/ar Septum. /finer head of Tr/cepsM. TRANSVERSE SECTION OF ARM BELOW INSERTION OF DELTOID M. 290 PLATE LXXIV, Muscula-cutaneaus A f . Biceps M. \l/e/?3 comes. \Brachidl 'A. Jupingf-arLnngusM. Radial recurrent A . Muscula-spiral N. External Intermuscular Septum Posterior ArticularBr. oFSuperiorProfundaA. MedianN. Vena comes. Internal [ufaneousN. Basilic V. Internal Intermuscu/ar Septum Inferior ProtundaA. Ulnar V. Triceps M. TRANSVERSE SECTION OF ARM ABOVE CONDYLES OF HUMERUS. 291 AMPUTATIONS OF THE UPPER EXTREMITY. 293 of the posterior ligament. Next siw through the base of the olecranon, and remove the forearm by cutting the supinator brevis, interossoous recurrent artery, anconeus, extensor carpi radialis brevior, extensor communis digitorum, extensor carpi ulnaris, flexor carpi ulnaris, and deep fascia. The principal vessels to be ligaled are the radial, ulnar, common interossemi- or anterior, and posterior inlerosseous, posterior ulnar recurrent, and the inter- osseuus recurrent artery. Tlie radial artery will be found on the radial side of the Hap, just beneath the ulnar margin of the supinator longus muscle. The ulnar artery will be found between the flexor sublimis digitorum and the flexor carpi ulnaris. The common interosseous or anterior and posterior interosseous arteries will be severed near their origin. Amputation through the middle of the arm. The circular or the antero- posterior flap method may be used in this amputation. In either the following structures will be severed on the front and inner side of the arm : Skin, superficial fascia, intercosto-humeral nerve, the internal cutaneous and external cutaneous branches of the musculo-spiral nerve, a cutaneous branch of the circumflex nerve, Ilie lesser internal cutaneous nerve (nerve of Wrisberg), internal cuta- neous nerve, branches of the superior and inferior profunda arteries, the cephalic vein, the deep fascia, the biceps and brachialis anticus muscles, the musculo- cutaneous nerve, the median nerve, the brachial artery and its vena? comites, the basilic vein, and the ulnar nerve ; on the posterior aspect of the arm, the triceps muscle, the musculo-spiral nerve, the superior profunda artery, the musculo-spiral nerve and the superior profunda artery will be seen immediately behind the bone, in close relation to that structure, and the brachial artery beneath the inner border of the biceps muscle. Amputation at the shoulder-joint. This amputation is performed for injury, tumors, malignant or benign, and disease of the joint. But one of the numerous methods of amputation at the shoulder-joint is described below, because practically the same structures are divided in all methods. The most important requisite is the surgeon's knowledge of the anatomy of the parts rather than of the different operations. The author prefers Spence's operation, a modification of the oval method. It is especially adapted to those cases of injury where there has been much comminution of the humerus. The posterior circumflex artery is not severed, the head of the bone can be disarticulated very readily, and the resulting stump is generally full and round. The incision extends from a point just external to the coracoid process, downward, in a line with the humerus, to a point just below the attachment of the pectoralis major muscle. The following struc- tures are divided : Skin, .superficial fascia, supra-acromial branches of the cervical plexus of nerves, branches of the anterior and posterior circumflex vessels, the. 294 WRGICAL ANATOMY. deep fascia, the cephalic vein, the humeral branch of the acromio-thoracic artery, the deltoid, the peetoralis major, and the anterior circumflex vessels. The incision is then carried backward, in a gentle curve, to the posterior border of the axilla. The skin and superticial fascia, with twigs of the posterior circumflex artery and circumflex nerve, the cephalic vein, the deep fascia, and the deltoid muscle will be severed. The posterior flap can now be readily stripped from the bone and joint. The flap will carry with it the terminal part of the circumflex nerve and posterior cir- cumflex vessels which enter its deep surface. The muscles attached to the greater tuberosity are then to be severed. They are the supra-spinatus, infra-spinatns. and teres minor. The subscapularis is next detached from the lesser tuberosity, the long head of the biceps divided, and the joint opened by dividing the capsular ligament. The arm is carried well inward, thus causing the head of the humerus to pass from the glenoid cavity. Before proceeding further a slight dissection of the axilla may be made to expose the axillary vessels, when they may be ligated before the remaining soft parts arc severed ; or the knife may be carried downward close to the bone on its internal aspect, the insertion of the teres major and latissimus dorsi muscles severed, and the anterior flap made by cutting from within outward. Care must be taken to have an assistant follow the knife down- ward with his fingers in contact with the vessels, and the outward cut should not be made until the surgeon is sure that the vessels are controlled by the assistant, The last incision severs the triceps muscle ; the brachial vessels ; basilic vein : the anterior circumflex artery ; the ulnar, median, musculo-spiral, internal cutaneous, lesser internal cutaneous, internal cutaneous branch of the musculo-spiral, and the intcrcosto-humeral nerve; the deep fascia; superficial fascia, and skin. LIGATIONS OF THE ARTERIES. Arteries are ligatured in the treatment of aneurysms ; to arrest hemorrhage ; check malignant growths; and previous to some operations, as amputation at the shoulder and removal of the tongue. Aneurysms are treated by medical and surgical means. The medical treat- ment consists of rest in bed in the recumbent position. Whenever possible, the part affected should be placed in such a position as to impede the flow of the blood current through the aneurysm, but not interfere with the return circulation. The diet should be non-stimulating, easily digested, in small quantity, and contain little liquid. All excitement must be avoided. Depletion may be practised to PLATE LXXV, m. I. ANEURYSMAL VARIX. II, VARICOSE ANEURYSM. Ill, METHOD OF ANTYLLUS IV. HUNTER'S METHOD, V, BRASDOR'S METHOD. VI. WARDROP'S METHOD. 295 LIGATIO.\S OF THE ARTERIES. 297 lower vascular pressure and allow the blood to begin to clot in the aneurysm. Drills which lower vascular tension, such as veratrum viride and aconite, should he given ; and iodid of jiotassiuin administered to break up the white corpuscles and liberate the librin torment. Various other methods of treating aneurysms have been practised. Among these are pressure, ligature, manipulation of the aneurysm, injection of coagulating materials, introduction of foreign bodies, and galvano-puncture. Pressure applied to the artery to the proximal side of the sac has given good results, and acts by checking the passage of blood through the sac and allowing it to clot. Digital pressure may be applied by relays of trained assistants. Its feasi- bility, however, is limited to aneurysms of the arteries of the extremities, as the brachial, superficial femoral, and popliteal. The pressure may be applied more conveniently by means of tourniquets which do not interfere with the return circulation. Ligatures have been used according to various methods. In the method of Anh/Uus, or the "old operation," the artery was tied on both sides of the aneurys- mal sac. The sac- was freely exposed, opened, the clot turned out, and the artery tied upon either side of the sac. This is not a good operation because there is copious bleeding, the artery is tied where its coats aie diseased, and consecutive or secondary hemorrhage is likely to occur. This method is the one commonly prac- tised in the treatment of traumatic false aneurysms. In these aneurysms there is not the same objection to tying the artery close to the aneurysm, since the walls of the vessel are not necessarily diseased at that point. In the method of And the sac is exposed and the artery tied immediately above the sac. In this method, as in that of Antyllus, the artery is tied where its coats are diseased. In /,Y<>- 1 $rj;<;lc.\l. ANATOMY. its position ; for if the vasa vasorum be torn, tlie danger of secondary hemorrhage is increased by preventing nutrition. The vasa vasorum should not be ruptured more than is necessary : this can be prevented if the operator will not unnecessarily separate the sheath from the artery, nor lift the vessel from its original position, nor depress the handle of the needle, thereby unnecessarily elevating the artery. The needle is always passed away from the structure which would be most endangered. If one vein accompanies the artery, the needle is passed away from the vein ; if the artery has two vena 1 comites and one accompanying nerve, the needle is passed away from the nerve. The needle may he passed either armed or unarmed. Before the needle is with- drawn always compress the artery between the curve of the needle and the finger and notice if the pulsation in the artery or its branches beyond the site of the operation is checked, and if any other structures are included in the ligature. The ligature should always be tied at a right angle to the course of the artery ; because if the ligature be placed obliquely, it is apt to become loose. The ligature is tied with a reef-knot, or a surgical knot, firmly enough to rupture the middle and internal coats of the artery. The undesirable sequela* of ligature of an artery are consecutive hemorrhage from loosening of the ligature' or diseased coats of the vessel, secondary hemorrhage from the breaking down of these diseased coats, sloughing around the ligature or imperfect organization of the clot, and rupture of the vessel. Gan- grene of the limb upon the distal side of the ligature may occur because of tin- slow and insufficient establishment of the collateral circulation. Sloughing of the sac may result. The pulsation in the sac may continue or return after having been absent : because the ligature was placed obliquely and became loosened, or was placed too far above the sac; the collateral circulation is too rapidly established through free anastomosis of branches above and below the ligature, or because of the presence of a vas aberrans. The axillary artery begins at the lower border of the first rib, and extends as far as the lower margin of the tendon of the teres major muscle. With the arm abducted to a right angle with the body, the course of the artery is represented by a line drawn from just to the inner side of the middle of the clavicle to the middle of the bend of the elbow. The artery is divided into three parts by the pectoralis minor muscle. The first part lies between the lower border of the first rib and the upper border of the muscle : the second under the muscle, and the third between the lower border of the muscle and the lower border of the tendon of the teres major. As a rule, the axillary artery is ligated only in its third portion. If a higher ligation be necessary, it is generally safer to ligate the third portion of the subclavian artery, as the first portion of the axillary artery is deeply seated, LIGATIONS OF Tin-: Aim-:uii-> or TIII-: UTTER KXTHKMITY. sos and the accompanying vein is large. prominent, and closely connected with the co-to-coraeoid ineinhraiie. The third portion of the axillary artery is quite acces- sible, he ing covered for a short distance l>y the pectoralis major muscle, beyond which it lies just beneath the skin, superlieial fascia and deep fascia when the arm is, abducted. In front of the third portion of the artery, when the arm is abducted, are the peetoralis major muscle, axillary fascia, inner head of the median nerve, and the internal cutaneous nerve. Ilehind it are the nxusculospiral and circumflex nerves, the subscapularis muscle, and the tendons of the latissimus dorsi and teres major muscles. On the inner side are the ulnar nerve, the axillary vein. and the lesser internal cutaneous nerve (nerve of Wrisberg) the latter being sepa- rated from the artery by the vein. On the outer side are the median and mnsculo- cutaneous (external cutaneous) nerves, the outer of the veiue comites of the brachial artery, and the coraco-brachialis muscle. The branches of this portion of the artery are the subscapular, anterior circumflex, and posterior circumflex. In ligating this portion of the axillary artery the arm should be carried outward to a right angle with the body. An incision is made in the line of the vose], beginning at the middle of the floor of the axilla. It is then carried downward about three inches along the inner border of the coraco-brachialis muscle, which can be easilv felt. The skin and superficial fascia, with small branches of the intercosto- humeral, internal cutaneous, and lesser internal cutaneous nerves, and branches of the long thoracic artery, are divided. The deep fascia is then incised, and the inner margin of the coraco-brachialis muscle exposed. The coraco-brachialis is drawn outward, and the position of the artery determined by its pulsation. The median nerve will then be exposed, and should be drawn outward, while the inter- nal cutaneous nerve is drawn inward. The outer of the vente comites of the brachial artery and the axillary vein being well exposed, the ligature can be passed around the artery from within outward. The unusual forms and relations of the axillary artery are the following : The third portion of the artery may be covered by a muscular slip from the latissimus dorsi. In ten per cent, of cases there are two large arterial trunks instead of one; one of them may be a common trunk of origin for the long thoracic, subscapular, posterior circumflex, and superior profunda arteries, while the other is the continuation of the axillary, and continues to form the brachial ; or one of the trunks ma}' be a radial or ulnar artery with an unusually high origin. When several of the branches of the axillary arise from a common trunk, as already stated, the main branches of the axillary plexus may surround this trunk and therefore be useless as landmarks for locating the main trunk of the axillary artery. 20 :',()(- SURGICAL ANATOMY. The <;,lliiti'i-ei ween the origin of the subscapular and circumflex arteries, the collateral circulation is established l>y the anastomosis of The supra-scapular and acroniio- . , the anterior and posterior circum- thoracic arteries ilex arteries, and The subscapular artery with the posterior circumflex artery. The subscapular artery. The arm is abducted to a right angle with the body, and the artery is exposed by an incision made through the floor of the axilla along the anterior border of the posterior fold of the axilla. The skin, superficial fascia, superficial vessels, posterior branches of the lateral cutaneous nerves, and the axillary fascia, are divided. The artery is found to the inner side of the anterior border of the latissimus dorsi, lying in the areolar tissue in front of the subscapu- laris muscle. The incision should avoid the axillary vessels which are upon the outer wall of the axilla. The long subsccqtular nerve lies to the inner side of the upper one-third of the artery and in intimate relation with the middle one-third. The subscapular n'm lies in front of the artery at its origin, and holds a varying relation to the remainder of the artery. The <]-ri/ arises from the subscapular artery about one inch from the origin of the latter. The lower xn/>- scapular nerve passes toward the teres major muscle just above or below the position of the dorsalis scapula? artery. The posterior circumflex artery and the circumflex nerve are most readily found upon the dorsal surface of the shoulder as they emerge from the quadrangu- lar space to supply the deltoid. The arm is abducted to a right angle with the body, and the incision is made along the posterior border of the deltoid. The center of the incision should be at the angle formed by this border of the deltoid and the axillary border of the scapula. The skin and fascia? are divided and the deltoid is drawn forward. The long head of the triceps and the lower margin of the teres minor are seen, and the finger may be introduced into the wound to detect the pulsation of the artery as it winds around the surgical neck of the humerus. The nerve lies upon the upper side of the artery. The quadrangular LIGATIONS OF THE M!TE[UE* r THE UPPER EXTHEMITY. 307 space is bounded upon the ouier side by the hunierus, upon the inner side by the long head of (lie triceps. above by the teres minor, and below liy the tercs major. As the nerve passes through the space it supplies a branch to the teres minor, liranclies to (lie deltoid, and gives oif cutaneous branches to tlie skin over the deltoid. The brachial artery is the continuation of the axillary artery, and begins at the lower edge of the tendon of the teres major muscle. Its course is on the same line as the axillary artery namely, from just to the inner side of the middle of the clavicle to the middle of the bend of the elbow, with the arm at a right angle to the body ; or from the junction of the anterior one-third with the middle one-third of the outer part of the floor of the axilla to the middle of the bend of the elbow. The artery is practically subcutaneous throughout its entire extent; except in the middle of its course where the median nerve lies in front of it ; and at its lower end where the bicipital fascia and median basilic vein are in front. In front of the artery are the skin, superficial and deep fascia>, inner border of the coraco-brachialis and biceps muscles, the median nerve at the middle of the arm, the median basilic vein, internal cutaneous nerve, and bicipital fascia at the bend of the elbow. Behind it, from above downward, are the long head of the triceps, the musculo-spiral nerve, the superior profunda artery, the inner head of the triceps, the insertion of the coraco-brachialis, and the brachialis anticus muscle. To its inner side are the ulnar nerve in the upper half of the arm, the internal cutaneous nerve and the basilic vein in the upper two-thirds of the arm, and the median nerve at the bend of the elbow. To its outer side are the coraco-brachialis and biceps muscles, as well as the median nerve in the upper part of the arm, and the tendon of the biceps at the elbow. Two veins accompany the artery, one lying on each side of it. The artery may be ligated at the lend of tlie elbow, or at the middle of the arm. In ligating it at the bend of the elbow the arm should be slightly flexed in order to make prominent the tendon of the biceps. The median, median basilic, median cephalic, and deep median veins usually join on a level with the point where the tendon ceases to be felt distinctly. Having located these points, the forearm should be extended and the arm abducted and allowed to rest on the olecranon. An incision, about two inches long, is made along the inner edge of the tendon of the biceps ; the upper end of the incision being about on a level with the tip of the internal condyle. The skin, superficial fascia, the anterior branch of the internal cutaneous and branches of the external cutaneous nerve, twigs from the inferior profunda and anastomotica magna arteries, with their veins, are severed. The median basilic vein will be found lying on the inner side of, and parallel with, the incision, and should be drawn to one side as soon as 308 SURGICAL ANATOMY. exposed. Tin- deep fascia and bicipital fascia arc divided in the line of the original incision, and the artery with its vena- coinites and the median nerve, which lies to its inner side, exposed. The veins should be separated from the artery, its sheath opened, and the ligature passed around the artery from within outward. Ligature of the hrachial artery or st retell ing of the median nerve at the bend of the elbow is not an advisable operation, because, if possible, scars should not be made at tlexures of joints. In ligating the braehial artery in tin 1 iitiildle of t}te arm the incision should be made along the inner edge of the biceps muscle. The skin, superficial fascia, twigs of the internal cutaneous nerve, and small branches of the superior profunda and anterior circumflex arteries will be divided. The deep fascia is then incised and the inner edge of the biceps muscle clearly demonstrated. The muscle is displaced outward, and the position of the artery determined by its pulsations. The median nerve is then exposed, generally lying over the artery in this part of its course. It should be drawn inward and the sheath of the vessel opened. The veiue coinites are then separated from the artery, and the ligature passed from within outward away from the basilic vein. After ligature of the braehial artery above the origin of the superior profunda artery the cnllntfi'iil circulation is established by the anastomosis between the posterior circumflex and superior profunda arteries. In ligating the braehial artery it is to be remembered that in about twenty per cent, of all cases there are two large arteries in the arm instead of one. This is due to the high origin of either the radial or nlnar artery, or to the presence of a vas aberrans. A third head of origin of the biceps sometimes crosses in front of the braehial artery near the middle of the arm. The median nerve is frequently under instead of over the middle portion of the artery. The braehial artery and the median nerve rarely pass toward the posterior surface of the internal condyle ; they pass around the supra-condyloid process and then in front of the elbow. This artery is most readily compressed at the middle of the arm where it lies upon the coraco-brachialis muscle; it is usually ligated in this location. The braehial artery is sometimes ligatured for an arterio-venous aneurysm. This is usually caused by a wound which involves both the artery and the adja- cent median basilic vein or venae coinites, but may occasionally result from disease. Arterio-venous aneurysms are of two varieties aneurysmal varix and varicose aneurysm. In an aneu/rysmal rmites will be exposed. The radial artery may arise from the braehial artery in the arm or from the axillary artery, and is at times quite superficial, overlying the supinator longus muscle. The ulnar artery may be ligated in the middle or lower one-third of the fore- arm ; but is seldom done in the upper one-third because <>f the deep position of the artery there. The upper portion of the ulnar artery describes a curve inward, to the ulnar side of the forearm. Its lower two-thirds correspond to a line drawn from a point midway between the internal eondyle of the humerus and the middle of the bend nf the elbow to the radial .side of the pisiform bone. The forearm should be supinated, and an incision made over the line of the vessel, just to the radial side of the tendon of the flexor carpi ulnaris. The incision divides skin, superficial fascia, twi^s of the cutaneous branches of the ulnar nerve, the anterior branch of the internal cutaneous nerve, and small branches of the ulnar artery. The deep fascia is exposed and incised and the tendon of the flexor carpi ulnaris brought into view. The tendon is drawn inward, and the ulnar vessels exposed. The sheath of the vessels is generally bound to the flexor profuudus muscle by a layer of fascia, which must bo divided. The ulnar nerve will be found near the artery, on its inner side, and its palmar cutaneous branch in front of the vessel. Displace the ulnar nerve and its palmar cutaneous branch inward. Separate the venae comites from the artery and pass the ligature from within outward. The ulnar artery occasionally arises from the braehial artery high in the arm, or from the axillary artery. When it has a high origin, it usually passes over the muscles which spring from the internal eondyle, and is, therefore, in much danger of being wounded, ruder the circumstances the recurrent and common interosseous branches arise from the continuation of the braehial artery. After ligature of the radial or ulnar artery the collateral rhrnliifinn is chiefly established through the palmar and carpal arches, and partially through the anastomosis of the muscular branches of the two vessels. STRETCHING OF THE NERVES. In stretching the main branches of the braehial plexus of nerves in the axilla the arm should be abducted to a right angle with the body, and an incision made in the line of these nerves. With the arm abducted as above mentioned, this line is drawn from just the inner side of the middle of the clavicle to the 312 SURGICAL A.\AT(t.MY. middle of the bend of the elbow. They will he found along the inner edge of the coraco-brachialis muscle, in company with the third portion of tlie axillary artery. The incision extends from tlie middle of the floor of the axilla, along the inner eil^e of the coraco-brachialis muscle for about three inches. The parts divided will include the skin, superficial fascia, small brandies of the Lntercosto-humeral, internal cutaneous and lesser internal cutaneous nerves, cutaneous branches of the long thoracic artery, and of the superficial external mammary artery when present. The deep fascia is then incised, and the inner edge of the coraco-brachialis muscle exposed. The first portion of the axillary vein and the third portion of the axillary artery will next be located. The vein lies in front of tlie artery with the arm in this position. The median and musculo-cutaneous nerves will be found on the outer side, the ulnar nerve on the inner side of the artery, and the musculo-spiral and circumflex nerves behind the vessel. The musculu-spiral and circumflex nerves can be readily reached by drawing the coraco-brachialis muscle and the brachial artery outward. These nerves are generally stretched in the arm separately. The course of the ulnar nerve in the lower part of the arm corresponds to a line drawn from a point on the inner side of the insertion of the coraco-brachialis to a point midway between the internal condyle of the humerus and the olecranon. To expose the nerve an incision should be made along its course, beginning about three inches above the internal condyle and extending to about one-half of an inch above. The skin and superficial fascia are to he divided, with brandies of the internal and lesser cutaneous nerves, and small branches of the inferior profunda and anastomotica niagna arteries. Next, the deep fascia should be incised, thereby exposing the internal intermuscular septum covering the inner head of the triceps muscle. Now incise the intermuscular septum, when will be seen the inferior profunda artery, which is readily located by its pulsations, and the ulnar nerve lying to the inner side of the vessel. The median nerve may be stretched at any part of its course in the arm. At the bend of the el how an incision should be made along the inner edge of the biceps muscle, beginning about on a level with the tip of the internal condyle of the humerus and extending downward for about two inches. The skin and superficial fascia, branches of the internal cutaneous nerve, and small branches from the anastomotica magna and anterior ulnar recurrent arteries will be divided. The median basilic vein will he found lying on the inner side of, and parallel with, the incision, and should be drawn to one side as soon as exposed. The deep fascia and bicipital fascia should be divided in the line of the original incision and the brachial artery exposed. The median nerve will be found on the inner side of the artery. >"//,' /;/> '///AY/ or riu: NERVES OF THE i'i>ri:n EXTREMITY. ::i:; The point of elect i< in lor exposing the musculo-spiral nerve is immediately above the external condyle of the humerus. The incision is made parallel with the inner margin of tlie snpinator longu.- nuisele. Skin and superficial fascia Avill ln> divided, with cutaneous twigs of the nmscnlo-spirnl nerve and superior profunda artery. The deep fascia is incised in the line of the original incision, and the inner bonier of the supinator longus muscle exposed. At the hottoin of the interval between this muscle and the hrachialis anticus the nerve is found. The terminal portions of the superior profunda and radial recurrent arteries are in relation with the nerve in the interval. To expose the radial nerve just above the middle of the forearm, an incision should he made in the line of the radial artery namely, from the middle of the bend of the elbow to the radial pulse. At this point the nerve will be found on the outer side of the artery ; but a short distance lower down, the nerve will be seen to leave the artery and pass to the posterior aspect of the forearm by going beneath the tendon of the supinator longus muscle. The incision divides the skin, superficial fascia, twigs of the anterior branch of the musculo-cutaneous nerve and of the anterior branch of the internal cutaneous nerve, and small branches of the radial artery. The deep fascia is then incised and the supinator longus muscle exposed. The muscle is drawn outward, and the radial artery located by its pulsations. The radial nerve will be found lying along the outer side of the artery. The ulnar nerve is best exposed in the forearm by an incision made immedi- ately above the wrist, to the outer side of, and parallel with, the tendon of the flexor carpi ulnaris. The skin, superficial fascia, twigs of the anterior branch of the internal cutaneous nerve, and a few small cutaneous arteries and veins will be divided. The deep fascia is incised and the tendon of the flexor carpi ulnaris exposed. This tendon should be drawn inward, and the ulnar artery located by its pulsations. The ulnar nerve will bo found to the ulnar side of the artery. The point selected in stretching the median nerve in the forearm is immedi- ately above the wrist. The incision should be made parallel with the ulnar border of the tendon of the flexor carpi radialis ; or, if the palmaris longus be present, between the tendons of these muscles. The skin, superficial fascia, twigs from the anterior branch of the internal cutaneous nerve, and a few small cutaneous arteries and veins will be divided. The deep fascia is incised and the tendon of the flexor carpi radialis exposed. This tendon should be drawn outward, when the nerve will be seen between the superficial and deep set of flexor tendons, to the radial side of the outermost tendon of the flexor sublimis digitorum. The median artery accompanies the nerve. At times this vessel is of considerable size, and assists in forming the superficial palmar arch in place of the ulnar artery. 314 SURGICAL AXATOMY. The brachial plexus of nerves and its large branches are stretched fur the relief of epileptiform convul-ions following injury ui' tin- plexus or one oi branches; in epilepsy with a definite aura beginning in the upper extremity ; in paralysis agitans following a nerve injury ; fur the relief uf pain ami anesthesia in anesthetic leprosy ; and fur the relief of pain and spasm of the muscles result- ing from a contusion or a lacerated wound which has involved a nerve. Stretch- ing of the involved nerve or nerves is not certain to afford permanent relief in any case, hut the operation is mure satisfactory in cases of irritation or sclerosis of the nerve from contusion or involvement of a lacerated wound in scar tissue. Irritation of the circumflex nerve causes spasm of the deltoid and teres minor muscles, and pain over the deltoid and upper part of the triceps muscle. Irrita- tion of the nuixciil't-x/iii-iil nerve produces spasm of the triceps muscle, radial exten- sors, superficial extensors, and deep extensors, and pain in the hack of the arm, outer side of the arm and forearm, radial side of the hack of the hand, and in the dorsal surface of the thumh, of the index finder, of the middle ringer, and of the radial side of the ring finger. Irritation of the median nerve causes spasm of the pronator radii teres, flexor carpi radialis, palmaris longus, flexor suhlimis digi- torum, flexor longus pollicis, radial side of flexor profundus digitorum, pronator quadratus, abductor pollicis, opponeiis pollicis, outer head of flexor hrevis pollicis, and the two radial lumhricales muscles, and pain in the front of the wrist, palm of the hand, and anterior surface of the thumh. of the index finger, of the middle finger, of the radial side of the ring finger, and in the back of the middle finger over the two distal phalanges. Irritation of the ulnar iic/'n causes spasm of the flexor carpi ulnaris, ulnar side of flexor profundus digitorum, palmaris brevis, muscles of the hypothenar eminence, the two ulnar lumbricales, interossei muscles, adductor pollicis, and the inner head of the flexor hrevis pollicis muscle, and pain in the ulnar side of the wrist, palm, and back of the hand, and in the palmar and dorsal aspects of the little finger and ulnar side of the ring finger. Operation upon the nerves of the upper extremity in tetanus, tetany, and athetosis has not been mentioned, for it is generally conceded that little or nothing is gained by this procedure. Primary or secondary suture of any of the large nerves of the upper extremity may he required after solution of the con- tinuity of the nerve. PLATE LXXVIII. - (J 15 .5 rt C g CL OPERATIONS FOR EXPOSURE OF THIRD PART, AXILLARY ARTERY AND LARGE BRANCHES OF BRACHIAL, BRACHIAL ARTERY AND MEDIAN NERVE AT MIDDLE OF ARM, AND ULNAR NERVE IN LOWER ONE-HALF OF ARM. 316 PLATE LXXIX. Median n. Skin Brachial a. Coraco-brachialis m. Short head of biceps m. Superficial fascia External vena comes of brachial a. Axillary v. Subscapular v. Teres major m. Internal cutaneous n.' Latissimus dorsi tendon Ulnar n. 1 Musculo-spiral n. Subscapular a. .esser internal cutaneous n. Subscapularis m. THIRD PORTION-AXILLARY ARTERY AND LARGE BRANCHES OF BRACHIAL PLEXUS. 317 PLATE LXXX, Biceps m Basilic v. Ulnar n. Brachial a. Internal cutaneous n. Median n. Deep fascia Superficial fascia Skin BRACHIAL ARTERY AND MEDIAN NERVE AT MIDDLE OF ARM. 319 PLATE LXXXI. Internal intermuscular septum Deep fascia Superficial fascia Skin Inferior profunda a. ,Ulnar n. Triceps m. 21 DINAR NERVE IN LOWER HALF OF ARM. 321 PLATE LXXXII. Suprascapular ; Superior intercostal a. Posterior scapular a Acrcmio-thoracic a. Subclavian a. Internal mammary a. Superior thoracic a. )\ y^ Long thoracic a. Vas aberrans loracic aorta Aortic intercostal a. -Radial recurrent a. -Posterior ulnar recurrent a, -Posterior interosseojs recurrent 5 DIAGRAM OF COLLATERAL CIRCULATION. 324 PLATE LXXXIII. Radial recurrent a. Radial a. Posterior interosseous recurrent Postoi ior interosseo'js a Anterior radial carpal a. Superficial volae a Dorsalis pollicis a. Posterior radial carpal a Princeps pollicis a. Dorsalis indicis a Radialis indicis a Deep palmar arch Brachial a. Ulnar a. Anterior ulnar recurrent ?. Posterior ulnar recurrent a. Common interosseous a. Anterior interosseous a. Muscular branches Anterior ulnar carpal a. Posterior ulnar carpal a. Deeo branch of ulnar a. Superficial palmar arch DIAGRAM OF COLLATERAL CIRCULATION. 325 PLATE LXXXIV, Deep fascia Bicipital fascia Biceps tendon Superficial fascia Deep fascia Supinator longus m. Radial n._ Radial a. ^^H ' Rrarhial a II % Vpnap romitps Superficial Fascia Radial a. Supinator longus Venae comites Inner tendon of flexor sublimis digitoruin Venae comites Pronator radii teres m. Flexor carpi radialis m. Flexor carpi radia'is tendon Superficial fascia Deep fascia Flexor carpi ulnaris tendon Ulnar a. Posterior carpal a. Ulnar n. Venae comites BRACHIAL ARTERY AND MEDIAN NERVE AT ELBOW, RADIAL ARTERY AND RADIAL NERVE AT MIDDLE OF FOREARM, RADIAL ARTERY IN LOWER THIRD OF FOREARM, AND ULNAR ARTERY AND NERVE ABOVE WRIST. 328 PLATE LXXXV, Skin Superficial fascia Deep fascia Bicipital fascia Brachial a. Biceps tendon Median n. Brachial venae comites BRACHIAL ARTERY AND MEDIAN NERVE AT ELBOW. 329 PLATE LXXXVI. s Skin Superficial fascia Deep fascia Radial a. Radial venae comites Pronator radii teres m. Supinator longus m. Extensor carpi radialis longior m. Flexor carpi radialis m. Radial n. RADIAL ARTERY AND NERVE AT MIDDLE OF EOREARM. 331 PLATE LXXXVII. Skin Superficial fascia Deep fascia Radial a. Radial venae comites Flexor carpi radialis tendon Supinator longus tendon Extensor carpi radialis longior tendon RADIAL ARTERY ABOVE WRIST. 333 PLATE LXXXVIII. Skin Superficial fascia Deep fascia Dinar a. Ulnar venae comites Flexor carpi ulnaris tendon Inner tendon of flexor sublimis digitorum m. Ulnar n. ULNAR ARTERY AND ULNAR NERVE ABOVE WRIST. 335 PLATE LXXXIX. Extensor primi internodii pollicls tendon Extensor secundii internodii pollicis tendon Line of incision for radial a. extensor ossis metacarpi pollicis tendon INCISION FOR RADIAL ARTERY IN "SNUFF-BOX." 337 PLATE XC. Radial Fxtenspr secundi internodii pollicis tendon Branch of radial n.< Deep fascia Superficial fascia Extensor primi internodii pcliicis tendon Extensor ossis metacarpi pollicis tendon Radial a RADIAL ARTERY IN "SNUFF-BOX." 339 PLATE XCI. Circumflex n. Posterior circumflex a. Posterior circumflex v. Superficial fascia Deep fascia Deltoid m Teres minor m, Infraspinatus m. Long head of triceps m POSTERIOR CIRCUMFLEX ARTERY AND CIRCUMFLEX NERVE. 341 PLATE XCII. Dorsalis scapulae a. Teres major m, Latissimu,s dorsi m Middle or long subscapular n ubscapular a. Subscapular v. Lower subscapular n. Subscapularis m. Deep fascia Superficial fascia SUBSCAPULAR ARTERY, MIDDLE AND LOWER SUBSCAPULAR NERVES, 343 PLATE XGIII. Superficial fascia- Deep fascia- Brachialis anticus m. Radial recurrent a.- Musculo-spiral n. tor longus m. MUSCULO-SPIRAL NERVE ABOVE EXTERNAL CONDYLE OF HUMERUS, 345 PLATE XCIV. Brachialis anticus m. Deep fascia Superficial fascia Skin Supinator longus m. Musculo-spira! n. Radial Recurrent a, MUSCULO-SPIRAL NERVE ABOVE EXTERNAL CONDYLE OF HUMERUS. 347 PLATE XCV. Superficial fascia Median a. Flexor carpi radialis tendon Palmar cutan.br. of median n. - Skin - Deep fascia Palmaris longus tendon Flexor sublimis digitorum m. Median n. MEDIAN NERVE ABOVE WRIST. 349 TIIK H.K'K OF THE .V/-.VA'. SHOULDER, AXD TJtl'XK. 351 Till: BACK OF THE NECK, silorLDEH, AM) 77,'f.VA". Surface anatomy. In the middle line, extending from tlir external occipital protuberance 1o the sacrum, is a longitudinal furrow, especially well pronounced in muscular subjects in the dorsal and lumbar regions. At the back of the neck it is called the nuchal, and below that point the spinal, furrow. It is produced by the presence of large muscular masses upon each side of the median line, and by the close adherence of the fascia' to the ligamentum undue and the supra-spinous ligaments. In the neck and dorsal region this groove lies between the trape/ius muscles, and in the lumbar locality between the erector spina- muscles. The spinal furrow is deepest in the lower dorsal and the upper lumbar region and, asit descends toward the sacrum, where the erector spina' muscles arc more tendinous, gradually fades away. A little above and external to the last spinous process of the sacrum (third sacral spine) is a depression which marks the position of the posterior supe- rior spine of the ilium. At the bottom of the nuchal furrow the bilid spine of the axis, and less distinctly the spines of the third, fourth, and iii'th cervical verte- brae, may be felt. The spines of the sixth and seventh cervical vertebra? stand out prominently. At the bottom of the spinal furrow the spinous processes of the dorsal, lumbar, and sacral vertebra: may be readily distinguished ; they become more pronounced when the body is bent forward. The scapula can be outlined at the back of the shoulder with facility in thin persons and with difficulty in obese persons. The vertebral border of the bone is felt at the side of the spinal furrow, and with the arm at the side of the body is parallel with the spinous processes of the vertebras. During abduction of the arm, the inferior angle of the scapula glides forward and the vertebral border makes an increasing angle with the spinous processes of the vertebra?. The axillary border is indistinctly felt, and the superior border can not be palpated through the over- lying muscles. AVhen the arms are hanging by the side, the superior angle of the scapula is opposite the upper margin of the second rib, and the inferior angle over- lies the seventh intercostal space. The inferior angle is a guide in the operations of aspiration or drainage of the pleural sac, which are performed in the fifth or sixth intercostal space at the side of the thorax. The spinous and acromion pro- cesses of the scapulae are subcutaneous and readily palpated, so that fractures of these processes are detected more easily than fractures of other portions of the scapula. The vertebral extremity of the spinous process is opposite the spinous process of the third thoracic vertebra, and the outer extremity joins the acromion process. The acromial angle is at the junction of the lower margin of the spinous process with the outer margin of the acromion process. From this angle the length of the upper extremity may be measured, the lower points selected being \~>-2 SURGICAL . I. V.I TO MY. the external eondyle of the humerusand the stylnid process of the radius, or the internal eomlylc of the humerus and the styloid process of the ulna. Over the inner end of the spine of the scapula is a depression which marks the position of the flat, triangular tendon, into which the lower libers of the trapt'/ius muscle are inserted. Above the spine of this bone, extending to the sloping Mirfacc of the shoulder, is a rounded elevation, produced by the trape/.ins resting upon the levator anguli scapula- and supra-spinatus muscles. When the patient is sitting and his arms hang between his thighs so as to depress (he scapula', the spines of those bones are almost opposite the fissures, between the upper and lower lobes of the lungs. The location of these fissures is of importance in the diagnosis of lobar pneumonia. The lower ribs can be felt at the back of the trunk, external to the erector spin.-i- muscle. As the twelfth rib does not always extend beyond the outer margin of the erector spina- muscle, the ribs should be counted from above downward. Just below the last rib and external to the erector spime muscle the kidney can be palpated and subjected to pressure. In percussion or auscultation at the back of the chest, the patient should cross his arms and lean forward so that the scapula; will be carried forward, and uncover as much of the posterior surface of the chest as possible. Because of the presence of thick masses of muscular tissue in the vertebral grooves, there is at all levels dullness on percussion close to the spinous processes of the vertebrae. The spines of the vertebrae lie in a straight line, and the spinal column presents no lateral curves. The back, like the spinal column, contains four antero-posterior curves the cervical, thoracic, lumbar, and pelvic. The cervical curve of the spinal column is convex forward, the thoracic curve concave forward, the lumbar curve convex forward, and the pelvic curve, which is formed by the -acrum and coccyx, concave forward. As seen in viewing the surface of the back, the cervical curve is concave backward, the thoracic convex backward, the lumbar concave backward, and the pelvic convex backward. Disease, overwork, or senility may alter the curves of the spinal column. Kyphosis, or fonvar<| curvature of the spine, is seen in rickety children, in old persons, and in laborers who do heavy work. In rickets the bones, containing less earthy matter than in health, become so abnormally flexible that the weight of the head bends the spinal column forward. In old persons and in laborers the forward curvature is caused by thinning or compression of the intervertebral discs. In lordosis the lumbar curve is exaggerated, and the depression in the lumbar region of the back is increased. This condition is seen in persons who, to retain their equilibrium, are compelled to throw the shoulders backward. It is observed in persons whose acetabula and hip-joints are situated unusually far PLATE XCVI. SURFACE MARKS OF BACK. 353 THE BACK OF THE XECK, SHOULDER, AXD TRUNK. 355 backward; in persons who, from spinal caries, liavo angular forward curvature of the upper part of the thoracic region of the spine and are compelled to increase the curve of the lumbar spine on account of the advanced position of the head and shoulders ; in pregnant women, and in obese persons. Lateral curvature of the spinal column in children is caused by sitting in one position for a long time ; by an unequal length of the lower extremities, which causes lateral inclination of the pelvis, and by empyema. Lateral curvature of the spinal column from malposition is most common in girls who have less exercise than boys and who are, therefore, more easily tired. If such a child sit for a long time upon a seat not well designed for comfort, or at a desk which is not of the proper height, the muscles of the back become tired, and the child curves the back so that the weight will be supported by the spinal column without much assistance from the muscles. By taking the child from school and giving her plenty of muscular exercise, massage, and gymnastics, and avoiding uncomfortable positions, the condition is corrected. If the lateral curvature lie produced by a short leg, a thick sole on the shoe of that leg will correct the deformity of the spinal column. The most common condition which causes shortening of one leg is hip disease. Nature tilts the pelvis to compensate for the shortness of the affected limb, and laterally curves the spinal column so that equilibrium may be maintained. When one lung is permanently collapsed as a result of empyema, the pulmonary space of that side is diminished, the ribs fall together, and the thoracic portion of the spinal column is curved. Curvature of the thoracic portion necessitates compensatory curvature of the lumbar portion of the spinal column. The concavity of the thoracic and the convexity of the lumbar curvature are directed toward the affected side. In the most common form of lateral curvature the thoracic region of the spinal column is deflected to the right and the lumbar region to the left. A line drawn along the tips of the spines of the vertebra) would be curved more than a line passing through the centers of the bodies of the vertebrae ; this difference is due to rotation of the vertebra so that the tips of the spines extend still farther in the direction of the convexity of the curve. When the lateral curve of the thoracic region of the spinal column is convex to the right, the right shoulder is elevated and the left shoulder depressed ; and if the thoracic region be deflected toward the left side, the left shoulder is elevated and the right shoulder depressed. Angular curvature of the spinal column is produced by caries of the vertebra. In this disease the bodies of some of the adjacent vertebra are more or less disintegrated by tubercular ulceration. Removal or softening of the bodies of the vertebra allows the superimposed weight to compress the bodies ; and as the vertebral arches are not compressible, the affected portion of the spinal SURGICAL . I.V. I T<> MY. column is sharply curved forward and the spinous processes of the involved vertebrae project backward. When caries of the vertebne is rapidly progressing, abscess formation occurs. These pus collections are called cold abscesses because ihey are not associated with heat and redness. In disease of the cervical vertebrae the pus accumulates behind the pre- vertebral fascia and the pharynx, forming a retro-pharyngeal abscess, which causes bulging in the posterior pharyngeal Avail, and difficulty in respiration and deglutition. It may rupture into the pharynx, gravitate to the posterior medias- tinum, or burrow outward to the posterior triangle, of the neck, and even enter the axilla. In caries of the dorsal vertebrae the pus usually gravitates to the diaphragm, passes under the internal arcuate ligament and the psoas fascia, and becomes a psoas abscess ; or it burrows under the external arcuate ligament and the anterior lamella of the lumbar fascia, and forms a lumbar abscess. The pus may, how- ever, ulcerate backward between the ribs, and cause a swelling in the back ; or it may follow the ribs and intercostal muscles forward, and produce a swelling at the side or front of the chest. Rarely, one of these abscesses may rupture into the esophagus, pleura, lung, or pericardium. In caries of the lumbar vertebrae the pus usually enters the sheath of the psoas muscle, and forms a psoas abscess. It gravitates downward under the psoas division of the iliac fascia. After passing under Poupart's ligament it produces a swelling at the outer side of the femoral sheath, where the psoas and the iliacus muscles approach the surface, from a common tendon, and occupy a common fascial compartment. These abscesses may, however, ulcerate through the iliac fascia and open into the peritoneal cavity, the ascending or descending colon or other portions of the bowel, the ureter, or the bladder. The pus sometimes passes under the anterior lamella of the lumbar fascia into the sheath of the quadratus lumbomm muscle, and forms a lumbar abscess. This abscess may ulcerate through the middle and posterior lamellae of the lumbar fascia and into the triangle of Petit, and produce a swelling near the middle of the crest of the ilium. From this description it may be understood how caries of the upper regions of the spinal column may produce a lumbar or a psoas abscess. The spines of the vertebrae may be used as landmarks in locating various structures. It should be remembered, however, that the tips of the spinons processes in the thoracic region, with the exception of the eleventh and twelfth, are not opposite the bodies of the corresponding vertebra?. The sixth cervical spine is situated opposite the cricoid cartilage and the commencement of the esophagus. PLATE XCVII, Lordnsis. Normal curve. Kyphnsis. Lateral curvature. 358 PLATE XCVIII. /&/-y2/ Lumbar caries Normal Curve Effaced Normal Curve Advanced darsi- Lumbar tariEs Angular Curvature. 359 THE BACK OF THE XECK, FlfOCLDKIt, AND TJ!f\k'. W] The serf nt li cervical spine corresponds to tho liigliost level of the apices of the lungs. The tliird thoracic spine lies opposite the point where the aorta approaches the spinal column, the highest level of the lower lobes of the lungs, and the bifurcation of the trachea. The fourth l/ioi-iteic spine is located opposite the point of termination of the arch of the aorta and the highest level of the heart. The eighth thoracic spine marks the lowest level of the heart and the level of the central tendon of the diaphragm. The ninth thoracic spin/' marks the level of the cardiac orifice of the stomach and the upper limit of the spleen. The fcntJi (Jioracic spin/.' locates the lowest level of the bases of the lungs and the level at which the liver reaches the abdominal walls posteriorly. The eleventh thoracic x/nne locates the lower limit of the spleen, the position of the supra-renal capsule, and the upper border of the right kidney. The twelfth thoracic spine is on a level with the lowest part of the pleurae, the aortic opening of the diaphragm, and the pylorus. The spine of the first hnn/x/r rerteln-n is situated opposite the renal vessels, the pelvis of the ureter, and the pancreas. The second linn/xir spine lies opposite the end of the spinal cord, the third portion of the duodenum, and the receptaculum chyli. The third lumbar spine is found just above the level of the umbilicus and below that of the lower border of the right kidney. The fourth lumbar spine is located opposite the bifurcation of .the aorta and the highest part of the crests of the ilia. The fifth lumbar spine marks the origin of the inferior vena cava. The third sacral spine lies opposite the termination of the sigmoid flexure and the lowest level of the spinal membranes. The tip of the coccyx marks the junction of the first and second portions of the rectum. The origins of the spinal nerves will not be found opposite their corre- spondingly numbered vertebra?, but as follows : The eight cervical nerves arise above the sixth cervical spine, the upper six thoracic nerves between the sixth cervical and fourth thoracic spines, the lotrer six thoracic nerves between the fourth and eleventh thoracic spines, the five lumbar nerves between the eleventh and twelfth thoracic spines, and the five sacral nerves between the last thoracic and first lumbar spines. The positions of the primary bronchi are indicated by lines extending from the third thoracic spine, or a point a little below it, to the dimple in the skin oii-J SURGICAL AXATOMY. over the mot of the spine of the scapula. Sounds are heard more dearly hi the right bronchus because it lies nearer the hack of the chest. The kidneys are Mtuated opposite the lower two ribs, with their inferior ends projecting below the twelfth ril>: 1<> ascertain if any tenderness exist in the diseased organ, pressure may be made upon it just under the last ril>, external to the erector spin.-e muscle. This, too, is the site selected when operating for removal of. and in exploratory operations upon, the kidney through the hack. The right kidney is lower than the left, more than half of it projecting below the last rib. The iliac crest at its highest point is located about opposite the fourth lumbar spine. The external surface of the spleen is directed outward and backward. This organ lies beneath the ninth, tenth, and eleventh ribs, from which it is separated by the peritoneum, diaphragm, the lower portion of the left lung, and the two layers of the left pleura. It holds an oblique position; its long axis almo-t corresponding to the line of the tenth rib. To either side of the spinal furrow in the upper part of the back are the scapulae, or shoulder blades, covered by the trapezius, deltoid, supra-spinatus, infra-spinatus, and latissimtts dorsi muscles. The scapula? cover the ribs from the second to the seventh inclusive. The parts of the scapula most readily felt are the spine and the acromion process, both of which are subcutaneous. The position of the acromion is marked by a depression when the arm is elevated, and in muscular subjects with the arm hanging loosely. At the junction of the outer border of the acromion with the lower border of the spine is found the acromial angle, from which point measurements are taken to determine the comparative lengths of the upper extremities. At the inner end of the spine of the scapula is a depression which corresponds to the triangular tendon into which the lower fibers of the trapezius muscle are inserted. The sloping superior surface of the shoulder is formed by the trapezius which covers the supra-spinatus and levator anguli scapula 1 muscles. The inferior angle of tin- /r< ;!<'.[ I, ANATOMY. intercostal and lumbar arteries. Branches of the posterior primary divisions of the spinal nerves furnish the nerve supply. The posterior primary branches of the spinal nerves, with the exception of the first cervical nerve (suboccipital), the fourth and fifth sacral, and the coiw- geal nerves, divide into external and internal branches: each primary branch supplii - sensory fibers to the skin in each region of the back. Both the external and internal branches supply nerves to the muscles of the back. The external branches in the cervical region supply the muscles, while the internal brandies of the second, third, fourth, and fifth nerves supply the skin, fascia>, and muscles. The internal branch of the posterior division of the second cervical nerve, the great occipital, pierces the complexus and trapezius muscles and ramifies, with the occipital artery, in the superficial fascia of the back of the scalp. The internal branches of the third, fourth, and fifth cervical nerves, after supplying the adjacent muscles, pierce the trape/.ius muscle near the liga- mentum nuchau and pass outward to supply the skin and fascia' over that muscle. The internal branch of the third cervical nerve is directed toward the scalp, and is called the smallest or third occipital nerve. The branches of the sixth, seventh, and eighth cervical nerves supply the adjacent muscles. In the tlinrncic rcf/imi the external branches of the posterior divisions of the upper six thoracic nerves supply the muscles, while the same branches of the lower six, after supplying the muscles, pierce the latissimus dorsi near the angles of the ribs to furnish nerves to the skin. The internal branches of the posterior divisions of the upper six thoracic nerves supply the muscles of the back, and pierce the trapezius near the spinous processes to supply the skin. The internal branches of the lower six thoracic nerves supply the muscles, and send small twigs to the skin. The external branches of the posterior divisions of the first three lumbar nerves supply the adjacent muscles, become subcutaneous at the outer border of the erector spins?, and pass over the crest of the ilium to supply the skin of the gluteal region ; the corresponding branches of the fourth and fifth lumbar nerves supply the erector spins; muscle. The internal branches of the posterior division of the lumbar nerves are small ; they supply the multiiidus spins 1 muscle. The posterior primary divisions of the upper four sdc/'nl m'rrrx emerge at the posterior sacral foramina, while the posterior division of the fifth emerges between the sacrum and coccyx. The posterior divisions of the upper three sacral nerves divide into external and internal branches, while the lower two sacral and the coccygeal nerves do not divide. The external branches of the posterior divisions of the upper three sacral nerves form loops upon the back of the sacrum between themselves and the PLATE Cl. 24 CUTANEOUS NERVES OF BACK 369 THK r>.-K <>r Tin-: .YAY-A', SJIOL'I.DKK, AXD TRUXK. ;::i external branch of (he last lumbar nerve, and upon the posterior surface of the great saero-sciat ie ligament form a secoml series of limps. From these loops are derived two or three nerves which pierce the glutcus maximus to supply the integument. The internal branches of the posterior divisions of the upper three sacral nerves supply the multilidus sphue muscle. The posterior divisions of the lower two sacral nerves form loops with the coccygeal nerve, and the posterior branch of the third sacral. Branches from these loops supply the skin over the coccyx. Cutaneous nerves. The skin of the back is supplied, in the ccrrical r<. by the internal brandies of the posterior divisions of the second, third, fourth, and fifth cervical nerves; in the tlnn-m-ii- ,-> >/!<>,> by the internal branches of the posterior divisions of the upper six thoracic nerves, and the internal and external branches of the posterior divisions of the lower six thoracic nerves; in the linubur ra/imi. by the external branches of the posterior divisions of the upper three lumbar nerves; over the sari-um and coccyx, by the external branches of the posterior divisions of the last lumbar nerve, upper three sacral nerves, the posterior divisions of the lower two sacral nerves, and by the coccygeal' nerve. The cutaneous nerves are accompanied by the cutaneous branches of the dorsal branches of the intercostal and lumbar arteries. DISSECTION. The superficial fascia is to be reflected after making incisions similar to those made in the removal of the skin. The deep fascia, dense and fibrous, invests the superficial muscles of the back (trapeziua and latissimus dorsi). It is continuous with all the adjacent deep fascia', and is attached to the following bony prominences of the back : The spines of the vertcbne with the intervening supra-spinous ligaments, the sacrum, the iliac crests, spines of the scapula-, and the superior curved ridges of the occipital bone. In the lumbar region the deep fascia blends with the glistening triangular aponeurosis of the latissimus dorsi muscle, which aponeurosis extends from the iliac crest and sacrum as high as the spine of the seventh thoracic vertebra. This aponeurosis should be preserved, as it constitutes the superficial, or posterior, layer of the lumbar fascia. The aponeurosis of the latissimus dorsi muscle is pierced at the outer border of the erector spinse muscle by cutaneous branches of the posterior divisions of the lumbar nerves. DISSECTION. The superficial layer of the deep fascia is to be reflected after making incisions similar to those made in removing the skin and superficial fascia. This exposes, in the neck, the trape/ius muscle, with the occipital triangle, and the sterno-cleido-mastoid muscle on its outer side ; at the level of the shoulders the trapeziua muscle, spine of the scapula, deltoid and teres major muscles, the infra- spinous fascia which covers the infra-spinatus and teres minor muscles ; below the :'>7-2 SURGICAL .I.V.I TOMY. level of the shoulders, the lower part of the Irapc/.ius muscle, the latissimus dorsi and its aponeurosis, and the posterior lihevs of (lie external and internal oblique muscles. The trapezius is a hrond, flat muscle, triangular in outline, with the bast of the triangle directed toward the spines of the vertebr;e and the apex toward the summit of the shoulder. It is one of the most extensive muscles of the body. It arises from the inner one-third of the superior curved line of the occipital b<> the external occipital protuberance, the ligamentum undue, the spinnus proce-s of the seventh cervical vertebra (vertebra prominens), the spinous processes of all the thoracic or dorsal vertebra', and from the intervening snpra-spimms ligaments. From this extensive origin its fibers converge outward to the top of the shoulder. It is inserted into the contiguous margins of the clavicle, acromion process, and spine of the scapula, Vicing attached to the outer one-third of the posterior border and upper surface of the clavicle, to the inner border of the upper surface of the acromion process, and to the entire length of the upper margin of the spine of the scapula. The lowermost libers form a triangular aponeurosis at the base of the spine of the scapula, over which it glides to he inserted into a tubercle at the inner extremity of the spine. Between the base of the spine of the 'scapula and the tendon is a small synovial bursa, which facilitates the movements of the tendon. The muscle is tendinous at its attachments, and is lusterless and adherent to the skin in the occipital region, while between the sixtli cervical and third thoracic spines the aponeurosis of origin is semi-elliptic, forming a complete ellipse with its fellow of the opposite side. The two trapczii form a diamond-shaped quadrangle, a trapezium (hence the name), with the lateral angles at the shoulders and the vertical angles at the occiput and twelfth dorsal spine. The trape/.ius muscle is subcutaneous throughout its entire extent ; in the neck it rests upon the complexus, splenius capitis et colli, levator anguli scapula-, ami rhomboideus minor muscles ; and in the hack upon the rhomboideus major, supra-spinatus, infra-spinatus, part of the serratus posticus superior, latissimus dorsi muscles, and the vertebral aponeurosis. Its anterior cervical border forms the posterior boundary of the posterior common triangle of the neck, and is nearly parallel with the posterior fibers of the sterno-cleido-mastoid muscle. BLOOD SUPPLY. From the princeps cervicis, superficial cervical, and posterior scapular arteries. NERVE SUPPLY. From the spinal accessory nerve and deep branches of the cervical plexus which enter the muscle beneath its anterior margin near the clavicle. ACTION. The upper fibers elevate the outer end of the clavicle and the point of the shoulder; acting from their insertion they rotate the head, draw it to the PLATE Gil. Splenius capitis m. Sterno-mas' Ltgamentum nuchae Trap- Rhomboideus major Latisslmus dorsi External oblique rn Aponeurosis of latissimus dorsi Internal oblique m. in triangle of Petit Comp!e> Great occipital n. Splenius capitis m. .Serratus posticus supeiioris m. Spltntus cofli rri , Levator anguli scapulae m. Rhomboideus minor m. Serratus magnus m, Supraspinatus m. Teres minor m. Outer head of triceps m, Long head of triceps m. Teres major m. nfraspinatus m. Rhomboideus major m. Serratus magnus m. Vertebral fascia Serratus posticus inferiors m. External oblique m. Internal oblique m. MUSCLES OF BACK. 373 Tin-: n.K'i\ <>/' Tin-: M-:CK. xii<>ru>rjL AM> Ti;r.\h'. 375 same side, ami extend the neck. The middle fillers draw the scapula Inward the spines (if the vertebra', and rotate il so as to raise the point of the shoulder. The lower lihers draw Hie shoulder Made inward and downward, and rotate it so as to elevate the point of the shoulder. Acting as a whole, the two muscles draw the seapuhe nearer together; elevate the point of the shoulder, and extend the neck, as in opisthotoiios. The ligamentum nuchee is a fibro-elastic band extending from the external occipital protuberance to the spine of the seventh cervical vertebra, where it is continuous with the supra-spinous ligaments of the hack. Fibrous extensions from it to the underlying spines of the cervical vertebra' form a septum between the muscles of the two sides of the back of the neck. It is almost rudimentary in man, but in the living body can be identified through the skin by dropping the head forward and allowing it to hang by its own weight, when the ligament can be demonstrated. In the lower animals, such as the horse, the ligamentum nuch;e holds the head up without any effort ; in fact, muscular force is required to carry the head to the ground and hold it there, as in grazing. The latissimus dorsi is a broad, flat, triangular muscle, with an elongated and twisted apex. It lies upon the lower portion of the back and outer side of the chest, covering a part of the side of the latter structure and all of the back from the level of the sixth thoracic vertebra to the crest of the ilium. This muscle arises by an aponeurosis from the spinous processes of the lower six thoracic, the lumbar, and the sacral vertebra?, the intervening supra-spinous ligaments, the back of the sacrum, and the posterior one-third of the outer lip of the crest of the ilium, and from the lower three or four ribs by fleshy finger-like bands which interdigitate with similar processes of the external oblique muscle. Its sacral origin is in common with that of the erector spime muscle, and its aponeurosis is the posterior layer of the lumbar fascia. Its fibers converge to the common tendon. The upper fibers pass horizontally outward over the inferior angle of the scapula; the middle, obliquely upward and outward ; and the lower, almost vertically upward. At the side of the chest they form a long, thick, fleshy mass, which sometimes receives an additional slip from the inferior angle of the scapula and passes along the axillary border of that hone in contact with the teres major muscle, around which the latissimus dorsi turns. It is inserted into the bottom of the bicipital groove between the insertions of the teres major and pectoralis major muscles by a flat tendon about three inches long. Near its insertion it twists upon itself so that the lower fibers are inserted highest, and the upper ones lowest. The inferior margin of the tendon is united to that of the teres major muscle, a bursa usually existing between the two. Sometimes there is another bursa between this muscle and the lower angle of the scapula. As it :;:<; SURGICAL ANATOMY. turns around the terea major it forms with that muscle the posterior told of the axilla. The latissimus dorsi muscle is subcutaneous throughout its entire extent, exeent at thai portion of its origin where it is overlapped by the trape/.ius muscle. It lies, 1'rom below upward, upon the vertebral aponeurosis which covers the erector spinse muscle and its upward continuations, the serratus posticus inferior muscle, lower ribs, external intercostal muscles, serratus magnus muscle, interior angle of the scapula, rhomboideus major, infra-spinatus, and teres major muscles. Just above the crest, of the ilium there appears, except in very muscular subjects, a triangular interval (trimii/Jr <>/ l' TRUNK. 377 attached to the posterior, or vertebral, border of the scapula : The levalor anguli scapula', above tlie base of the spine; the rhomhoideus minor, opposite the base of the spine: and the rhomboideus major, below the base of the spine. The posterior belly of the omo-hyoid muscle, which arises from the upper border of the seapula internal to the supra-scapular notch, will also be seen. The levator anguli scapulas muscle arises from the posterior tubercles of the transverse processes of the upper four cervical vertebra' by lour tendinous slips. These slips unite to form a Hat, fleshy mass, which passes down the back of the side of the neck to be inserted into the vertebral border of the scapula above the base of the spine. Its superficial surface is in relation with the deep fascia of the neck, the middle scalene, the trapexius, and sterno-mastoid muscles, the internal jugular vein, the spinal accessory nerve, and some of the descending branches of the cervical plexus. It rests upon the spleiiius colli, transversalis colli, cervicalis ascendens, and serratus posticus superioris muscles, and the posterior scapular vessels. BLOOD SUPPLY. From the vertebral, ascending cervical, superficial cervical, and posterior scapular arteries. NERVE SUPPLY. From the fifth cervical nerve, and additional filaments from the deep branches of the cervical plexus. ACTION. This muscle draws the upper angle of the scapula upward and forward, at the same time rotating that bone so as to depress the summit of the shoulder. Acting from its insertion, it inclines the neck to one side and extends it. The rhomboideus minor is a small, fiat, ribbon-like muscle arising from the lower end of the ligamentum undue, the last cervical and first thoracic spines, and the supra-spinous ligament. It extends obliquely downward and outward, and is inserted into the vertebral border of the scajmla opposite the base of the spine. It is covered by the trapezius muscle, and lies upon the serratus posticus superioris and intercostal muscles, the posterior scapular artery, and the ribs. BLOOD SUPPLY. From the posterior scapular artery. NERVE SUPPLY. From a branch of the fifth cervical nerve which will be seen beneath the rhomboidei. ACTION. It draws the scapula upward and inward toward the spinal column. The rhomboideus major muscle lies below the rhomboideus minor, and is about three times as broad. It arises from the upper four or five thoracic spines and their suj>ra-spinous ligaments, and is inserted into the vertebral border of the scapula opposite the infra-spinous fossa. This muscle and the rhomboideus minor have similar relations, except that the former covers part of the sj>lenius colli, the vertebral ajioneurosis, and the erector spina? muscle. 378 SURGICAL ANATOMY. BLOOD SriM'LY. From the posterior scapular artery. NERVE SITI-LY. From a branch of the fifth cervical nerve. ACTION. It draws the scapula upward and inward toward the spinal column, and rotates the scapula so as to depress the summit of the shoulder. DISSKCTION. The fatty tissue covering the posterior belly of the omo-hyoid muscle should lie removed, when this muscle will be seen to arise from the superior border of the scapula immediately internal to the supra-scapular notch, and in part from the ligament converting the notch into a foramen. Jt passes forward and upward into the neck. Divide the posterior belly of the omo-hyoid muscle a short distance above its origin and reflect it upward. This will expose the supra-scapular artery and nerve on their way to enter the supra-scapular fossa. Before dividing the levator anguli scapuhe and rhomboidei muscles the dissector should turn his attention to the cap of the shoulder, as this covers many of the structures to be considered. The cap of the shoulder is formed by the deltoid muscle, which is covered by a part of the dec)) fascia called the deltoid aponeurosis. This aponeurosis is thick and strong, and sends many septa between the bundles of fibers of the muscle. The fascia is continuous with that covering the pectoralis major muscle in front and the infra-spinatus muscle behind, and is attached to the clavicle, acromion, and spine of the scapula. The deltoid muscle resembles an inverted triangle with an indented base ; or the (Jreek J inverted; hence its name, delta-like. It arises from the shoulder girdle opposite the insertion of the trape/dus muscle, and so marked is this that the clavicle and acromion process and spine of the scapula seem but bony inter- ruptions in one grand trapezo-dcltoid muscle which is inserted into the middle of the humcrus. It arises from the outer one-third of the anterior border of the clavicle, the outer border and superior surface of the acromion process, and the entire lower border of the spine of the scapula. From these points its fibers converge to form a thick, short tendon, which is inserted into the middle of the outer side of the shaft of the humcrus opposite the insertion of the coraco- brachialis muscle. Its fibers are irregular in direction, presenting a twisted appearance, and coiling behind one another. There are several main bundles. Many tendinous intermuscular septa subdivide it, giving insertion to some of its fibers and origin to others, the largest bundle coming from the tip of the acromion. On account of these tendinous septa the deltoid resembles the glutens maximus muscle. It rounds off the shoulder. Superficially, this muscle is related to the platysma. deep fascia, and supra-acromial nerves. It almost completely envelopes the shoulder-joint, and is separated from the greater tuberosity of the humerus by THE HACK or THE NECK, SlfOfLDER, AXI) Th'l'XK. 379 a large samilated bursa. It covers the coracoid process of the scapula, the tendons of the pectorales niajur and minor, the coraeo-hraehialis, the subscapularis, the short and long heads of the biceps, the supra-spinatus, the infra-spinatus, the tores minor, the long and outer heads of the triceps, the coraco-clavicular and coraco-acromial ligaments, the circumilex vessels and nei've, and the upper end of the humerus. Anteriorly, it adjoins the upper, outer margin of the pectoralis major muscle, with which it forms the delto-pectoral sulcus in which is lodged the cephalic vein and the descending hranch of the acromio-thoracic artery. Abscess of the shoulder- joint, or the subdeltoid hursa, rarely burrows through the substance of this muscle but usually points at one of its borders. Atrophy of the deltoid muscle causes the acromion process to appear more prominent, and a depression to exist beneath it. This condition is caused by disuse, as in ankylosis of the shoulder-joint ; more frequently by diseases of the spinal cord, as acute anterior polio-myelitis ; by ascending neuritis of the circum- flex nerve, usually due to disease of the shoulder-joint and causing paralysis of the muscles ; and by injury of the circumflex nerve, by a blow or fracture of the upper part of the humerus. A careless observer might regard a case of atrophy of the deltoid one of dislocation of the head of the humerus. BLOOD SUPPLY. From the acromio-thoracic, the anterior and posterior circumflex arteries. NERVE SUPPLY. From the circumflex nerve. ACTION. It is by no means simple in its action. The whole muscle abducts the arm, raising it to a right angle with the body. The posterior fibers retroduct the arm and rotate it outward ; and the anterior fibers draw the arm forward and rotate it inward. Thus this muscle draws the arm forward, backward, or outward, and rotates it inward or outward. DISSECTION. Divide the deltoid muscle about one inch from its origin, and reflect it downward. This will expose the structures already enumerated as in relation with its under surface. When reflecting the muscle, the bursa separating the deltoid muscle from the acromion process and the greater tuberosity may have been opened ; but if it be still intact, it should be incised and its extent carefully noted by passing the finger into it. In some injuries of the shoulder this bursa may be affected by traumatic bursitis, with marked increase of the fluid contents of the sac. This would cause much prominence of the shoulder cap, an'd the consequent increased pressure would account for much of the pain experienced upon movement of the arm. Divide the latissimus dorsi muscle just above the level of the inferior angle of the scapula, and reflect the two portions. The lower portion of the muscle should not be reflected beyond its aponeurosis. SURGICAL A\'.\T<>MY. Circumflex arteries and nerve. The anterior and posterior circumflex arteries and the ciivunilk'x nerve, which \\-.\\c been described \vitli tlie dissection of the axilla, will be seen on the under surface of the ivilecied deltoid muscle. The teres major muscle arises IVoni the lower part of the axillary border of the scapula, from the back of the inferior angle of the scapula, and from the fibrous septum between the teres major and the teres minor muscle. It passes upward and outward, and forms a short, flat tendon, which is inserted into the posterior bicipital ridge of the humerus behind the tendon of the latissimus dorsi muscle, from which it is separated by a bursa. BLOOD SUPPLY. From the suhscapular and posterior circumflex arteries. NERVE SUPPLY. From the lower subscapular nerve. ACTION. It assists the latissimus dorsi muscle in adducting the arm and rotating it inward ; if the arm be fixed upward and forward, it rotates the scapula by drawing the lower angle forward ; and if the scapula also be fixed, it assists the latissimus dorsi muscle in drawing the trunk upward and forward, as in climbing. The infra-spinous fascia is a dense membrane which covers the infra- spiuatus and teres minor muscles. It is attached to the circumference of the infra-spinous fossa, and gives origin to some of the fibers of the muscles which it covers. At the outer border of the deltoid it gives off a process which passes over that muscle. This fascia must lie removed to expose the underlying muscles. The teres minor muscle hugs the axillary border of the scapula. It arises from the upper two-thirds of the dorsal surface of this margin. There is an aponeu- rotic lamina between it and the teres major muscle, and a lamina between it and the infra-spinatus muscle. It passes upward and outward, slightly diverging from the teres major muscle, and is inserted into the lowermost of the three facets upon the greater tuberosity of the humerus and the bone just below it. It is covered by infra-spinous fascia, the deltoid muscle, and the deep fascia, while beneath it are the scapula, the dorsalis scapuhe artery, the long head of the triceps muscle, the teres major and the subscapularis muscle, and the back of the shoulder-joint. Its upper border is in contact with the infra-spinatus muscle, while the lower border assists in forming the upper boundary of the subscapular triangle. BLOOD SUPPLY. From the posterior circumflex and dorsalis scapula? arteries. NERVE SUPPLY. From the circumflex nerve. ACTION. It is an external rotator of the humerus, adducts it, protects the back of the shoulder-joint, and aids in holding the head of the humerus in place. The long head of the triceps muscle is seen arising from the axillary border of the scapula just below the glenoid fossa. It passes downward toward the back of the arm, between the two teres muscles, and through the triangular space formed by PLATE Teres major m. Branch of dorsalis scapulae a. Latissimus dorsi tendon Supraspinatus m. Infraspinatus m. Greater tuberoslty of humerus Teres minor m. Circumflex n. Posterior circumflex a. Long head of triceps m. Outer head of triceps m. Ulnar n.- Flexor carpi ulnaris m- -Tendon of triceps m. POST-SCAPULAR MUSCLES AND TRICEPS MUSCLE. 381 Till-: BACK OF Till- NECK, sllon.DKi;. A.\f> VV.T.VA'. 383 their divergence (the teres minor being behind ami the teres major in front), sub- dividing tliis interval into an inner triangular and an outer rectangular space. (See nisseetion of Axilla.) TllO former gives passage lo llie dorsalis scapulie Vessels, and (In- latter to the posterior cireinnllex vessels and the eireunillex nerve. The scapula lias two dorsal fosse, separated by the spine of the bone, and one anterior, or ventral, making tbree in all. from each of \vliich arises a muscle; these muscles are known as the supra-spinalus, infra-spinalus, and snbseapularis. The infra-spinatus muscle, thick and triangular, arises from' the inner two- thirds of the infra-spinous fossa, the under surface of the spine of the scapula, the infra-spinous fascia, and the septum separating it from the teres major and teres minor muscles. Its fibers converge to a tendon which passes below the concave outer border of the spine of the scapula, and crosses the, shoulder-joint to be inserted into the middle facet upon the greater tuberosity of the hnmerus. A hursa, which sometimes communicates with the shoulder-joint, occasionally exists between the tendon and the outer border of the spine of the scapula. This muscle is covered by the infrorepinous J'uxrin, which sends fibrous septa between it and the two teres muscles, and is continuous with the deep fascia of the arm. It is also covered by the deltoid, trape/ius, and latissimns dorsi muscles. Beneath it lie the scapula, the supra-scapular vessels and nerve, the dorsalis scapula- vessels, and the capsule of the shoulder-joint. External to it are the teres major and teres minor muscles. BLOOD Sri-i'LY. From the dorsalis .scapula? and supra-scapular arteries. NERVE SUPPLY. From the supra-scapular nerve. ACTION*. It rotates the humerus outward, adducts it, and aids in holding the head of the bone in place. DISSECTION. The acromial end of the clavicle and the acromion process should be removed so as to fully expose the top of the shoulder-joint, and afford a clearer view of the muscles inserted into the greater tuberosity of the humerus. The supra-spinous fascia is a dense membrane covering tin- supra-spinatus muscle, and giving origin to some of its fibers. It is very thick internally but less so under the coraco-acromial ligament. It is attached to the margins of the supra-spinous fossa, and must be removed to expose the supra-spinatus muscle. The supra-spinatus muscle fills the supra-spinous fossa, and arises from its inner two-thirds, the upper surface of the spine of the scapula, and the fascia covering the muscle. Its fibers converge into a short, stubby tendon which crosses the top of the shoulder-joint under the acromion process, to be attached to the uppermost of the three facets upon the greater tuberosity of the humerus. It is closely adherent to the capsule of the shoulder-joint. Superficial to it arc the thick and dense supra-spinous aponeurosis, the trapezius muscle, clavicle, acromion, coraco-acromial ligament, and deltoid muscle ; under it are the capsule of the ::si SURGICAL ANATOMY. shoulder-joint, the supra -scapular vessels and nerve, the oino-liyoid muscle, and the scapula. IJi.ooi > SriTLY. From the supra-seapular artery. NKUVK Sci'iM.v. From the supra-scapular nerve. ACTION. ii assists the dehoid muscle in abducting the arm, and holds the head of the Immerus in contact with the glcnoid fossa. DISSK.CTIO.X. Having carefully studied the muscles just descrihed, the dissector, in order to ohtain a better view of the vessels and nerve which puss beneath them, should divide the levutor anguli scapuhe muscle near its attachment to the base of the scapula and relied it upward; the infra-spinatus und supra- spinatus muscles should be divided near their insertions and reflected inward ; divide the rhomboidei muscles near their insertion and reflect them outward; then divide the teres minor muscle near its insertion and reflect it downward. The posterior scapular artery, one of the terminal branches of the trans- versal is colli. runs beneath the vertebral border of the scapula, between (lie levator anguli scapuhe and the rhomboidei muscles behind and the serratus magnus muscle in front, to the inferior angle of that bone, where it anastomoses with the terminal portion of the subscapular artery. In its course it gives oft' numerous branches, which ramify on the dorsal and ventral aspects of the scapula. These branches supply the rhomboidei, supra-spinatus, infra-spinatus, trape/.ins, and latissimus dorsi muscles. They anastomose with the supra-scapular, dorsal is scapuhe, subscapular, and branches of the intercostal arteries. The posterior scapular often arises from the third portion of the subclavian artery. The nerve to the rhomboidei muscles accompanies this artery. The supra-scapular artery, a branch of the thyroid axis, after passing along the under surface of the posterior belly of the oino-hyoid muscle enters the- supra- spinoiis fossa by passing over the transverse ligament. It traverses that fossa beneath the supra-spinatus muscle and passes around the outer border of the spine of the scapula and enters the infra-spinous fossa. Within these foss;e it supplies the supra-spinatus and infra-spinatus muscles, and anastomoses with the posterior scapular and dorsal is scapuhe arteries. The supra-scapular nerve accompanies the supra-scapular artery, but passes through the supra-scapular notch beneath, and not over, the transverse ligament. It supplies twigs to the supra-spinatus muscle and the shoulder-joint, and passes into the infra-spinous fossa together with the supra-scapular artery, terminating in the infra-spinatus muscle. The dorsalis scapulae, a branch of the subscapular artery, enters the infra- spinous fossa by winding around the axillary border of the scapula under the teres minor muscle. It supplies the infra-spinatus muscle and anastomoses with PLATE CIV, Branch of Acromio-thoracic a. Suprascapular a. Branch of posterior circumflex a 1 . Subscapular a. Suprascapular a Posterior scapular a. Dorsalis scapulae a.- 25 ANASTOMOSES OF ARTERIES AROUND THE SCAPULA. 385 THE HACK OF THE .VAY'A", SIIriJ)KK, A.\J> TRL'XK. ;jx7 thu supra-scapular and posterior scapular arteries. It sends a branch along the axillarv border of the scapula, between the teres major and minor muscles, to the posterior surface of the inferior angle of that bone, where it again anastomoses with the posterior scapular artery. The subscapularis, a large and triangular muscle, fills the subscapular fossa. It arises from the inner two-thirds of that fossa, except from the front of the upper and lower angles and the front of the posterior border to which the serratus magnus muscle is attached. Its scapular origin is fleshy, except at the ridges on the bone, where it is tendinous. Its filters converge 1 to a strong tendon, which lies below the base of the coracoid process, and is inserted into the lesser tuberosity of the humerus ; those libers arising from the axillary border are inserted into the sur- gical neck of the humerus for an inch below the lesser tuberosity. Between its tendon and the coracoid process is found a large bursa, which communicates with the shoulder-joint. The muscle is covered by a thin subscapular aponeurosis attached to the entire circumference of the fossa, and gives origin to some of its fibers. In addition to this covering it lies behind the serratus magnus and coraco-brachialis muscles, the short head of the biceps, the axillary vessels and brachial plexus, and some of their branches. Behind, it rests upon the scapula, the teres minor muscle, the long head of the triceps, the capsule of the shoulder- joint., and the intervening bursa. To its outer side are the teres major and the latissimus dorsi muscle, the posterior circumflex and dorsalis scapulas vessels, and the circumflex nerve. BLOOD SUPPLY. From the axillary and subscapular arteries. NERVE SUPPLY. From the short and lower subscapular nerves. ACTION. It is an internal rotator of the humerus, draws the arm downward after it has been raised, and holds the head of the humerus in place. DISSI-XTIOX. The anterior dissection of the chest having been made, the clavicle should be severed, when the serratus magnus muscle will be the only remaining connection between the trunk and upper extremity. The serratus magnus muscle is closely attached to the upper outer anterior part of the thorax. It arises by nine fleshy (limitations from the upper eight ribs and the corresponding interspaces, two digitations arising from the second rib. From this broad origin its fibers converge backward around the chest for insertion into the anterior surface of the vertebral border, and of the upper and low^er angles of the scapula. It is therefore irregularly quadrilateral in form. It is con- veniently divided for examination into an upper, middle, and lower part. The vpper .portion narrowest, thickest, a,nd shortest consists of the first two digita- tions arising from the first and second ribs and intervening intercostal space, whence it passes upward, outward, and backward to the anterior surface of the 388 SURGICAL ANATOMY. superior angle of the scapula. The ////i>,ii'in consists of the remaining four digitations arising from tlie fifth, sixth, seventh, and eighth rihs and the corresponding intervals, and interdigitates with the upper serrations of the external oblique muscle. Its fibers pass upward, outward, and backward, to be inserted into the oval space on the anterior surface of the inferior angle of the scapula. The serratus magnus muscle is in relation superficially with the pectoralis major and minor muscles, the Bubscapularis and latissimus dorsi muscles, the subclavian and axillary vessels, the axillary or brachial plexus of nerves, and the posterior or long thoracic nerve. It covers the ribs, intercostal muscles, and serratus posticus superioris muscle. BLOOD SUPPLY. From the axillary and intercostal arteries. NERVK Srppi.v. From the posterior or long thoracic nerve (external respiratory of Bell). This nerve is seen running over the muscle at the side of the chest. ACTION. It draws the scapula and entire shoulder forward, thus increasing the forward reach of the arm and antagonizing the rhomboidei muscles and central fibers of the trape/ius muscle. If the scapula- are fixed close to the spinal column, tin 1 lower fibers of the two serratus niagnus muscles will evert and draw the ribs upward, thus pushing the sternum outward and increasing the antero-posterior and lateral diameters of the chest. It helps sustain weight upon the shoulder by holding the lower angle of the scapula forward, thus aiding the trapezius in drawing the summit of the shoulder upward. It holds the scapula? firmly against the chest wall, and its lower portion by far the strongest pulls the inferior angle of the scapula forward. It steadies the scapula while the deltoid muscle abducts the arm to a right angle ; then, by rotating the inferior angle forward, it can raise the arm to the vertical position. Paralysis of the serratus magnus muscle prevents the deltoid muscle from raising the arm, and allows the inferior angle and verte- bral border of the scapula to project from the chest, producing the " winged scapula." Before leaving the shoulder the student should carefully note the actions and relations of the magnificent tripartite muscle composed of the trapezius, deltoid, and pectoralis major muscles. The trapezius and deltoid may be considered, for many reasons, a single muscle ; so may the pectoralis major and deltoid muscles be viewed as one muscular mass, arising from an extensive origin, beginning at the costo-chondral margin and extending up the side of the sternum and along the PLATE GV. Long head of b: Subscapularis m. Teres major m. Long head of triceps m. Latissimus dorsi tendon Outer head of triceps m. ectoralis major tendon Inner head of triceps m. SUBSCAPULARIS MUSCLE AND SUBSCAPULAR TRIANGLE, 390 PLATE CVI. External intercostal m. Internal interco: ' Serratus magnus m. SERRATUS MAGNUS MUSCLE. 391 Tin-: n.\<-K or '////; M-CK. AM> n;r.\K. 393 entire length of the shoulder girdle /'. e., tlie clavicle, acromion, and spine of the >ca|iula. It is inserted into the anterior bicipital ridge and the middle of the outer side of the shaft of the humcrns. The following grouping of the seventeen mnselcs attached to the scapula will be of considerable aid to the student in remembering them : Three to the vertebral border, Three to the axillary border, Three to the three fossa;, Three to the coracoid process, . Three irregularly attached, . . Two to the spine of the scapula, Serratus magnus muscle. Hliomboideus minor muscle. Rhomboideus major muscle. Long head of triceps muscle. Teres minor muscle. Teres major muscle. Supra-spinatus muscle. Infra-spinatus muscle. Subscapularis muscle. Short head of biceps muscle. ( '( iraco-braebialis muscle. 1'ectoralis minor muscle. Omo-hyoid muscle. Long head of the biceps muscle. Levator anguli scapulae muscle. J Trapezius muscle. I Deltoid muscle. DISSECTION. It is now necessary to remove the arm and scapula. This can be done by dividing the coraco-clavicular ligament, the serratus magnus muscle at its origin, and the axillary vessels and brachial plexus of nerves. There are two serratus posticus muscles the superior and inferior. The superior lies under the three muscles attached to the vertebral border of the scapula ; and the inferior under the latissimus dorsi muscle. The serratus posticus superioris is a thin, flat muscle, which arises by a thin aponeurosis from the lower end of the ligamentum nucha?, the last cervical and the upper two or three thoracic spines; it is inserted by four fleshy slips into the upper borders of the second, third, fourth, and fifth ribs beyond their angles. The fibers are directed downward and outward. It is covered by the trapezius and the levator anguli scapulae and the rhomboidei muscles. It lies upon the splenius muscle, the vertebral aponeurosis covering the upper continuations of the erector spime, upon the intercostal muscles, and the ribs. NERVE SUPPLY. From the branches of the second and third intercostal nerves. SURGICAL ANATOMY. ACTION. It draws upward the ribs to which it is attached, assisting in inspiration. The serratus posticus inferioris is also a thin. Hat muscle. It arises by an aponeurosis from the last two dorsal and upper two or three hmihar spines and from the interspinous ligaments. It passes upward and outward, and is inserted by four fleshy (limitations into the lower borders of the lower four ribs beyond their angles. It is covered hy (lie latissimus dorsi muscle and rests n|>on the erector spina- and its continuations, upon the levatores costaruin and intercostal muscles, and rihs. Its upper margin blends with the vertebral aponeurosis. 'NiOKVK Sri'iM.Y. -From the branches of the tenth and eleventh intercostal nerves. ACTION. It depresses and fixes the lower four ribs, resisting the action of the diaphragm, which tends to elevate and draw forward the lower ribs; it is a muscle of inspiration. The splenius muscle (spleuius capitis et colli) arises from the lower two- thirds of the ligaineiitum nuchie, and, hy tendinous slips, from the spines of the last cervical and upper six thoracic vertebra', and the intervening interspinous liga- ments. It passes upward and outward, expanding into a broad, flat muscle which divides into two portions, one going to the head and the other to the neck. The head segment (splenius capitis) is inserted into the mastoid process of the temporal bone and the surface of the occipital hone helow the superior curved line and under the sterno-cleido-mastoid muscle. The neck segment (splenius colli) is inserted into the posterior tubercles of the transverse processes of the upper three or four cervical vertebra 1 . The muscle is covered by the posterior process of the deep cervical fascia and the following muscles: Trape/ius, serratus posticus siipe- rioris, rhomboidei, levator anguli scapuhe, sterno-cleido-mastoid. It lies upon the spinalis dorsi, semi-spiualis colli, longissimus dorsi, cervicalis ascendeiis, trans- versalis colli, complexus, and trachelo-mastoid muscles. NEKVK .SrrrLY. From the external branches of the posterior divisions of the lower cervical nerves. ACTION. It extends the head and neck, rotates them to the same side, and flexes them laterally. The vertebral fascia or vertebral aponeurosis is a thin, fibrous membrane, which extends from the spines of the vertebra' to the angles of the ribs, and binds down the muscles occupying the vertebral groove. It is continuous below with the upper margin of the serratus posticus inferioris muscle and the aponeurosis of the latissimus dorsi muscle; above, it passes under the serratus posticus superioris muscle and is continuous with the deep fascia over the spleuius muscle. This aponeurosis separates the deeper muscles of the back from the posterior axo- PLATE CVII, Complexus m. Ligamentum nuchae Splenius capitis m.- Splenius colli m, Scalenus posticus m Serratus posticus superioris m. Supraspinous lig. Vertebral fascia Serratus posticus inferioris m.- Appneurosis of latissimus dorsi m External oblique m Internal oblique m Obliquus capitis superioris m. Complexus m. Tracrtelo-mastoid m. Transversalis coMi m. Semispinalis colli m. .Cervicalis ascendens m. Semispinalis dorsi m. Accessorius ad ilio-costalem m, Spinalis dorsi m. Longissimus dorsi m. Ilio-costalis m. Erector spinaem. Lumbar fascia .Cut edge of posterior lamella of lumbar fascia External oblique m. Internal oblique m. MUSCLES OF BACK, 396 PLATE CVII I. C o in p I e x u s m -. Trachelo-mastoid m Semispinalis colli m Transversalis colli m. Cervicalis ascendens in. Semispinalis dorsi m. Longissimus dorsi m. Spinalis dorsi m .- Accessorius ad ilio- costalem m_ Ilio-costalis m. Rectus capitis posticus minor m. Rectus capitis posticus maior m. Obliquus capitus superiorly m. Obliquus capitis inferioris m. Levatores costarum Multifidus spinaem. Middle lamella of lumbar fascia Lumbar fascia edge of posterior lamella of lumbar fascia Transverse process DEEP MUSCLES OF BACK, 397 Till: HACK OF Till-: .V/-.VA', S7/OT l.DT.R. AND TRUNK. appendicular muscles /. e., those muscles upon tin- l>ark which unite the trunk with the upper liml>. DISSKCTION. Beginning from helow, remove the aponeiirosis of tlie latissimus dorsi muscle, the serratns posticus inferioris muscle, and the vertebral fascia. Pivi'le tlie Berratus posticus superioris and splcnius muscles at their middle, and reflect the two halves. This exposes tin- erector spina- muscle and its upward continuations and the greater part of the complexus muscle. The erector spinae is an extensive, seetional lihro-muscular mass with uumer- uus costo-vertebral attachments extending the entire length of tlie spine. It is densely lihrons and poiuteil in the sacral region, becomes very muscular in the lumbar region, and divides in the lower dorsal region into three main sections an outer, ilio-costalis or sacro-lumbalis ; an inner, spinalis, dorsi ; and an intermediate, longissimus dorsi. It arises, by a thick aponetirosis, from tlie spines of the lower two thoracic, from the lumbar, and upper four sacral vertebra 1 ; from the back of the sacrum and the posterior sacro-iliac ligaments; and, by muscular tib(>rs, from the posterior fifth of the crest of the ilium. The whole mass ascends, and divides below the last rib into three column?-. The outer column is subdivided into the ilio-costalis or sacro-lumbalis and its continuations the accessorius ad ilio-costalem and the cervicalis ascendens muscle. BLOOD SUPPLY. From the posterior scapular, intercostal, and lumbar arteries. NERVE SUPPLY. From the external branches of the posterior divisions of the spinal nerves in the lumbar, thoracic, and cervical regions. The ilio-costalis or sacro-lumbalis is the outermost and fleshy part of the erector spinae muscle, and is inserted into the angles of the ribs from the sixth to the eleventh, and into the inferior border of the twelfth, the transverse processes of the lumbar vertebra, and into the middle layer of the lumbar fascia. Very often this muscle is inserted as high as the fourth rib. NERVE SUPPLY. From the external branches of the posterior divisions of the spinal nerves in the lumbar and thoracic regions. ACTION. It depresses the ribs, and is, therefore, a muscle of expiration. It keeps the body erect by extending the spinal column, which it also flexes laterally. DISSECTION. Turn the ilio-costalis muscle outward to expose the origins of the accessorius muscle. The accessorius muscle (accessorius ad ilio-costalem) is the upward continua- tion of the ilio-costalis muscle and arises, by tendinous slips, from the angles of the lower six ribs, internal to the costal insertions of the ilio-costalis muscle. It is inserted into the angles of the upper six ribs and the transverse process of the seventh cervicalfvertebra. it HI SURGICAL AXATOMY. XKRVE SUPPLY. From the external branches of the posterior divisions of the spinal nerves in the thoracic region. ACTION. With fixation of the lower six ribs hy the ilio-costalis this muscle draws downward the upper six rihs, as in expiration. It also aids in extension and lateral flexion of the spinal column ; acting from its insertion, it elevates the lower six ribs, as in inspiration. The cervicalis ascendens is the continuation of the am-ssorius muscle and arises from the upper four or five rihs internal to the costal insertions of the acces- sorius muscle. It passes upward over the first rib and the Iransversalis colli muscle, and is inserted into the posterior tubercles of the transverse processes of the fourth, fifth, and sixth cervical vertebrae. XKKVK SUPPLY. From the external branches of the posterior divisions of the spinal nerves in the thoracic and cervical regions. ACTION. It extends the neck and flexes it laterally. Acting from its inser- tion, it elevates the ribs to which it is attached, as in inspiration. The intermediate column consists of the longissimus dorsi, transversalis colli, and trachelo-mastoid muscles. BLOOD SUPPLY. From the princeps cervicis, proftmda cervicis, intercostal, and lumbar arteries. The longissimus dorsi muscle is the largest of the erector spinse group. Its inner side lies in close contact, in the lumbar region, with the spinalis dorsi muscle, from which it often receives a slip. It has two series of insertions an inner, or vertebral ; and an outer, or costal : the inner series, by rounded tendons, is attached to the transverse processes of all of the thoracic and the lumbar vertebra? ; the outer series, by fleshy and tendinous slips, is inserted into all of the ribs external to the tubercles, the transverse processes of the lumbar vertebra-, and the adjacent portion of the middle lamella of the lumbar fascia. XKRVE SUPPLY. From the external branches of the posterior divisions of the spinal nerves in the lumbar and thoracic regions. ACTION. It extends the spinal column, flexes it laterally, and depresses the ribs, as in expiration. The transversalis colli muscle is the upward continuation of the longissimus dorsi, and is situated upon the inner side of that muscle. It arises from the trans- verse processes of the upper five or six thoracic vertebrae, and is inserted into the posterior tubercles of the transverse processes of the cervical vertebras from the second to the sixth. NERVE SUPPLY. From the external branches of the posterior divisions of the spinal nerves in the thoracic and cervical regions. ACTION. It extends the neck, flexes it laterally, and rotates it to the same side. mi: HACK or THE .Y/-.V-A-. Miori.nr.n. A.\D TRUNK. 401 The trachelo-mastoid muscle is .-iuiated upon the inner side of the trans- versalis rolli. and forms the continuation of that muscle toward (lie head. It arises from the transverse processes ( f the third, fourth, fifth, and sixtli thoracic vertebra* and, hy additional tendons, from tin- hack of the articular processes of the lower three or four cervical vertebra'. It proceeds upward as a small muscle which is inserted into the posterior border of the mastoid process under the splenius and sterno-mastoid muscles. It lias frequently a tendinous intersection near its insertion. NERVE SUPPLY. From the external branches of the posterior divisions of the spinal nerves in the thoracic and cervical regions. ACTION. It Ilexes the head laterally, rotates it to the same side, and with the aid of its fellow extends the head. The inner column of the erector spiiue muscle consists of the spinalis dorsi muscle. The spinalis dorsi muscle is the continuation of that portion of the erector spina- muscle which arises from the upper two lumbar and lower two thoracic spines. It is inserted into the spines of the upper thoracic vertebra', varying from four to eight in number. Its outer lower side is closely connected with the longissimus dorsi muscle, and, at its insertion, with the seini-spinalis dorsi muscle. BLOOD SUPPLY. From the intercostal and lumbar arteries. NERVE SUPPLY. From the posterior branches of the spinal nerves of the thoracic region. ACTION. It extends the spinal column and flexes it laterally. The spinalis colli muscle, analogous to the spinalis dorsi muscle, generally extends from the fifth and sixth cervical spines to the spine of the axis. It varies considerably, and may be attached to two additional spines below the origin and insertion here given. This muscle is not present in all subjects. NERVE SUPPLY. From the posterior 'branches of the cervical nerves. ACTION. It extends the neck and inclines it laterally. The complexus is a broad, bulky muscle occupying the cervical and upper thoracic regions, and passing upward and inward to the occipital bone. It arises from the posterior surface of the transverse processes of the upper six thoracic and the last cervical vertebrae, the posterior surface of the articular processes of the cervical vertebrae (third to the sixth) and the spine of the seventh cervical vertebra. It is inserted into the occipital bone between the superior and inferior curved lines. Near the center it has a transverse tendinous interruption. It lies beneath the trape- zius and the splenius muscles, external to the ligamentum nuchae, which separates it from its fellow of the opposite side, and internal to the trachelo-mastoid and 26 SI RGICAL A ^. \T<)MY. transversalis colli muscles. It lies upon the obliquus capitis superioris ami inferioris muscles, the rectus capitis po-tidis major and minor muscles, the serni- spinalis colli muscle, the profunda cervicis and princeps cervicis arteries, and the posterior division of the spinal nerves, including the great occipital nerve which pierces it. BLOOD Srpi-LY. From the profunda cervicis, princeps cervicis, and super- ficial cervical arteries. NKKVK SCPI-LY. From the suboccipital, great occipital, and the internal branches of the posterior divisions of the third, fourth, and fifth cervical nerves. ACTION. It is a powerful extensor of the head and neck, flexes the head laterally, and turns the face slightly to the opposite side. The biventer cervicis, which is the innermost portion of the complexus, is a small, delicate, double-bellied muscle. DISSECTION. The attachments of the erector spinse and the spinalis dorsi muscles to the spines of the vertebrae and the insertions of the longissimus doi>i and the ilio-costalis muscles should be severed, and the muscles reflected down- ward. Next detach the accessorius, the cervicalis ascemlens, the transversal!- colli, and the trachelo-mastoid muscle. Sever the complexus muscle where the great occipital nerve pierces it, preserving that nerve intact ; reflect the two portions, when the suboccipital and the other nerves which enter its deep surface will be brought into view. In reflecting the trachelo-mastoid and the complexus muscle avoid injuring the occipital, princeps cervicis, and profunda cervicis arteries, and the deep cervical vein. The occipital artery in the deepest part of its course will be found beneath the mastoid process of the temporal bone. At this point it is covered by the origin * of the posterior belly of the digastric muscle, the mastoid process, the trachelo- mastoid, splenius capitis and sterno-mastoid muscles. This artery winds through the interval between the mastoid process of the temporal bone and the transverse process of the atlas ; it is separated from the vertebral artery by the rectus capitis lateralis muscle, and then traverses the occipital groove upon the mastoid portion of the temporal bone. It crosses the superior oblique and a portion of the complexus muscle and at the posterior border of the splenius pierces the trapezius muscle together with the great occipital nerve. The vessels arising from this portion of the artery are the princeps cervicis, the mastoid, and muscular arteries. The princeps cervicis artery is given off near the posterior border of the splenius muscle, and divides into a superficial and a deep branch. The superficial branch pierces the splenius, and, passing downward between that muscle and the trape/ius, anastomoses with the superficial cervical artery. The deep branch passes THE HACK <>!' THE \ECK, SHOrLDEH, AM) TKl'XK. 40;; downward between the complexus and semi-spinalis eolli muscles and anastomoses witli the profunda cervicis artery and some small branches of the vertebral artery. The mastoid branch passes through the mastoid foramen to supply the mastoid cells, the diploe, the walls of the lateral sinus, and the dura mater. The muscular branches supply adjacent muscles. The profunda cervicis artery, a branch of the superior intercostal, emerges from between the transverse process of the last cervical vertebra and the neck of the first rib, and, passing upward between the complexus and the semi-spinalis colli muscle anastomoses with the princeps cervicis artery and branches of the ascending cervical and vertebral arteries. The deep cervical vein is formed by small veins in the suboccipital triangle, usually receives the occipital vein, accompanies the princeps cervicis and then the profunda cervicis artery, and empties into the vertebral or innominate vein. The previous dissection exposed the deepest muscles of the back ; these are, from below upward, the following : The multifidus sphue, the levatorcs cost-arum, semi-spinalis dorsi, semi-spinalis colli, the obliquus capitis superioris and inferioris, the rectus capitis posticus major and minor. The middle layer of the lumbar fascia, the occipital, the princeps cervicis, and the profunda cervicis arteries, the great occipital and suboccipital nerves, and the suboccipital triangle were also revealed. BLOOD SUPPLY. These deep muscles are nourished by the vertebral, princeps cervicis, profunda cervicis, intercostal, and lumbar arteries. The semi-spinalis dorsi muscle is composed of small, fleshy bellies uniting rather long tendons. It arises from the transverse processes of the fifth to the tenth thoracic vertebra;, and is inserted into the spines of the upper four thoracic and lower two cervical vertebrae. It is covered by the longissimus dorsi and the spinalis dorsi muscle, and rests upon the multifidus spinae muscle. NERVE SUPPLY. From the internal branches of the posterior divisions of the spinal nerves. ACTION. It is an extensor and lateral flexor of the spinal column. The semi-spinalis colli muscle is thicker and shorter than the semi-spinalis dorsi. It arises from the transverse processes of the upper five or six thoracic vertebrae, and is inserted into the spines of the second to- the fifth (inclusive) cervical vertebra}. It is covered by the branches of the posterior division of the cervical nerves, the princeps cervicis and profunda cervicis arteries, the deep cervical vein, and the complexus muscle ; it rests upon the multifidus spinaj muscle. NERVE SUPPLY. From the internal branches of the posterior divisions of the spinal nerves. KM SURGICAL ANATOMY. ACTION. It is an extensor and lateral flexor of the cervical portion of the spinal column. The levatores costarum muscles arise from the tips of the transverse pro- cesses of the last cervical and all of the thoracic vertebne except the twelfth, and are inserted into the upper bonier and outer surface of the next rib below, between the tubercle and single. The lower levatores divide into two slips, the additional one going to the second rib below. They lie external to the semi-spinalis dorsi muscle. NERVE SUPPLY. From the intercostal nerves. ACTION. The levatores, as indicated by their name, elevate the ribs, thus assisting the external intercostal muscles. The multifidus spin* muscle is situated in the groove at the side of the spinous processes, under the semi-spinalis muscle, and extends from the axis to the sacrum. The fibers arise from the groove on the dorsal aspect of the sacrum, the posterior superior spine of the ilium, the posterior saero-iliac ligament, and the die)) surface of the apoucurotic origin of the erector spline muscle. In the lumbar region the fibers arise from the mammillary processes ; in the thoracic, from the transverse processes; and in the cervical, from the articular processes of the lower four vertebra 1 . From these numerous points of origin the muscular bundles pasa upward in an oblique direction, and are attached to the spinous processes and lamina? of the vertebra? ; the most superficial bundles are the longest, and pass to the third or fourth vertebra above their origin ; while the deeper ones pass to the next vertebra and to the second or third above. NERVE SUPPLY. From the internal branches of the posterior divisions of the spinal nerves. The rotatores spinae, situated under the multifidus spinac muscle, are eleven small quadrilateral muscles, each of which arises from the upper back part of a transverse process of a thoracic vertebra, and ascends to be inserted into the lower margin and outer surface of the lamina of the vertebra immediately above, extending as far inward as the base of the spinous process. NERVE SUPPLY. From the internal branches of the posterior divisions of the spinal nerves. ACTION. They rotate the spinal column, turning the body of the vertebra toward the opposite side ; and, acting bilaterally, extend the spinal column. The interspinales muscles extend in pairs between contiguous vertebral spines, the muscles of the two sides being separated by the interspinous ligaments. There are six cervical pairs between the axis and the first thoracic vertebra, and these are the most distinct. Two or three thoracic pairs are found between the first and second thoracic spines above and the eleventh and twelfth below, and PLATE CIX. Rectus capitis posticus minor m. Obliquus capitis superioris m. .Occipital a. Suboccipital n. Princeps cervicis a. Vertebral a. Great Occipital n. Smallest occipital n. Posterior occipito-atlantal lig. Posterior arch of atlas Obliquus capitis inferioris m' Rectus capitis posticus major m.' Multifidus Spinae m. Semispinalis dorsi m. SUBOCCIPITAL TRIANGLE. 406 Till: BACK OF Till- XM'h; SHot'I-DEH. A\I> TUl'XK. -l<>7 ~ionally a pair may be found between the second and third thoracic spines. There are lour lumbar pairs between ihe five lumbar spines. Sometimes there are pairs ahove the iirst and below tin- last lumbar spine. NI:I;VK SrrrLY. From tlie internal branches of the posterior divisions of the spinal nerves. ACTION. Thev assist, to a slight decree, ill extending the spinal column. The intertransversales muscles lie between the transverse processes of adjacent vertebra'. There are seven pairs of cervical intertransversales muscles on each side of the spinal column. They are found between the two adjacent anterior and two adjacent posterior tubercles, and are separated by the anterior branch of the cervical nerve emerging from the corresponding intervertebral foramen. They extend from the atlas to the Iirst thoracic vert el mi. The ivctus capitis lateralis. extending between the jugular process of the occipital bone and the transverse process of the atlas, corresponds to an inti rtransversalis muscle. The Ilini-in-ic iiitri-ti-iitixiTi'xiih-x muscles are found only in the lower three intervals. There are four pairs of /inn/mi- iii1<-,-l,- triangle by piercing the posterior occipitoatlantal ligament. The Kii/iniri/iitii/ neroe passes through the posterior occipito-atlantal ligament ami between the verd'hral artery and the posterior arch of the atlas. It is small and supplies the posterior reeti, the obliqui, and the complexus muscle. The rectus capitis posticus major muscle, cone-shaped, arises by its apex from the spine of the axis, passes upward, outward, and backward, and is inserted by its base- into the inferior curved line of the occipital bone and the surface im- mediately below it. It is covered by the complexus muscle, and, at its insertion, by the superior oblique muscle; it rests upon the posterior arch of the atlas, the occipital bone, i he posterior occipito-atlantal ligament, and the rectus capitis posticua minor muscle. NKHVH STI-PLY. From the suboccipital nerve. ACTION. It extends the head and rotates it to the same side. The rectus capitis posticus minor muscle, triangular in shape, arises by its apex from the tubercle upon the posterior arch of the atlas and ascends directly upward. It is inserted into the inferior curved line of the occipital bone and the surface immediately below it. It is covered by the complexus and the ivcms capitis posticiis major muscle, and lies upon the posterior occipito-atlantal ligament. XKUVK SUPIM.Y. From the suboccipital nerve. ACTION. It extends the head. The obliquus capitis superioris muscle, also triangular in shape, is smaller than the inferior oblique muscle. It arises by its apex from the back of the upper surface of the transverse process of the atlas, and passes upward and backward. It is inserted into the occipital bone between the two curved lines beneath the com- plexus muscles. It is covered by the complexus, the trachelo-niastoid, and the splenins muscles, and rests upon (he rectus capitis posticus major muscle, vertebral artery, and posterior occipito-atlantal ligament. NKUVK SUPPLY. From the suboccipital nerve. ACTION. It extends the head, ilexes it laterally, and rotates the face to the opposite side. The obliquus capitis inferioris muscle, larger than (he superior oblique muscle, arises from the spinous process of the axis between (he attachments of the rectus capitis posticus major and semi-spinalis colli muscles. It passes almost directly outward, and is inserted into the tip of the transverse process of the atlas. It is covered by the complexus muscle and the great occipital nerve, the latter curving over its lower margin, and rests upon the posterior atlo-axial ligament and the vertebral arterv. THE BACK OF THE XKCK, SHOULDER, AND TRUXK. 409 NERVE SUPPLY. From the suhorcipital nerve. ACTION. It rotates the atlas upon the axis, carrying the face to the same side. The lumbar fascia is a dense aponeurotic structure seen in the space between the last ril> and the crest of the ilium. It assists in supporting the muscles of the loin, and gives partial origin to the internal oblique and transversalis muscles of the abdominal wall. It is attached above to the last rib and the cartilage of the eleventh rib, and below to the posterior one-third of the crest of the ilium. Internally, it divides into three layers. The posterior layer passes behind the erector spinre muscle and blends with the aponeuroses of the latissimus dorsi and serratus posticus inferioris muscles, which aponeuroses are continued upward as the vertebral fascia. This division of the lumbar fascia is attached to the spines of the lower thoracic, lumbar, and sacral vertebras. The middle layer passes between the erector spinse muscle and the quadratus lumborum, and is attached to the tips of the transverse processes of the lumbar vertebra?. The anterior layer passes in front of the quadratus lumborum, and is attached to the anterior surface of the bases of the transverse processes of the lumbar vertebra?. The upper portion of the anterior layer which extends between the transverse process of the first lumbar vertebra and the tiji and lower border of the last rib is called the ligamentum arc/mtum (.rt< mum. The lumbar fascia is overlapped to the outer side of the erector spina? muscle by the latissimus dorsi and external oblique muscles. It is an important guide in operations upon the kidney or colon through the loin. In lumbar abscess, pointing at Petit's triangle, the pus burrows through the middle and posterior lamellae of the lumbar fascia. The nerves of the back are derived from the posterior primary divisions of the spinal nerves. "With the exception of the first and second cervical nerves, the posterior primary are smaller than the anterior primary divisions. The posterior primary division of the first cervical nerve (suboccipital) runs backward, pierces the occipito-atlantal ligament, passes between the vertebral artery and the posterior arch of the atlas and through the suboccipital triangle. It supplies twigs to the rectus capitis posticus major and minor muscles, the obliquus capitis superioris and inferioris muscles, and the complexus muscle. A small branch usually communicates with the great occipital nerve. The posterior primary division of the second cervical nerve divides into an external and an internal branch, the latter being much the larger. The external branch sends a twig to the inferior oblique muscle, and then ends in the com- plexus and the trachelo-mastoid muscle. The internal branch is called the great occipital nerve. It sends twigs upward and downward which communicate with the first and third cervical nerves, forming the posterior cervical plexus of Cruveil- hier. The great occipital nerve then ascends, turning upward and backward over IK) srur.K'M. .\\ATOMY. the lower bonier of the inferior ol>li<|iir muscle and under cover of the eoni]>lexus. It crosses over the suboccipital triangle, pierces the complexus muscle which it supplies and the outer bonier of the trape/.ius near the superior curved line of the occipital bone. It then families in the superficial fascia of the back of the scalp with the occipital artery. The posterior divisions of the third, fourth, and fifth cervical nerves pass backward at the outer border of the semi-spinali.s colli muscle, and divide into external and internal branches. The c.dcrnul bi'riiiir]ii-K supply the semi-spinalis colli and the complexus muscle, between which they lie. and send brandies to the multifidus spline. They next pass between the complexus muscle and the liganientum nuch;e, pierce the origin of the trapezius muscle, and are distributed to the integument of the back of the neck. The smallest occipital nerve is the internal branch of the posterior division of the third cervical nerve. It passes upward and communicates with the great occipital nerve. The external branches of the posterior divisions of the sixth, seventh, and eighth cervical nerves supply the splenius, the complexus, the cervicalis asceiidens, and the transversalis colli muscle. The internal branches supply the semi-spinalis colli and the multifidus spline muscle. The posterior primary divisions of the thoracic nerves pass backward between the transverse processes of the thoracic vertebra;. They then divide into external and internal branches, the former increasing and the latter decreasing in size from the second to the last. The external branr/icx of the posterior divisions of the upper six or seven thor- acic nerves terminate in the longissimus dorsi and accessorius muscles. The lower five or six pierce the outer insertions of the longissimus dorsi, and are then found between that muscle and the accessorius. After piercing the latissimus dorsi muscle they reach the integument of the lower and outer part of the back. The intiriifil />/-iinfli/-x supply the longissimus dorsi, the spinalis dorsi, the semi-spinalis dorsi, the multifidus spline, the rotatores spiine. the intertransversales, and the interspinales muscles. The upper six or seven branches pierce the origin of the trapeziua muscle and supply the integument. The posterior divisions of the lumbar nerves also divide into external and internal branches, the latter going entirely to the multifidus spiine muscle. The i.i-fi-riil. /tranches of the upper three lumbar nerves pierce the aponeurosis of the latissimus dorsi near the outer border of the erector spiine muscle, cross the crest of the ilium, and are distributed to the integument of the gluteal region. The Till-: BACK OF THE XI-X'K, SHOULDER, AXD THl'XK. 411 external branch of the fourth lumbar nerve supplies, and that of the fifth tci, the erector spin;e muscle: the last communicates with the first sacral nerve. The posterior primary divisions of the upper four sacral nerves emerge at the posterior sacral foramina ; that division of the fifth sacral nerve emerges at a point between the sacrum and coccyx, and the coccygeal nerve issues from the lower opening of the spinal canal. The posterior divisions of the upper three sacral nerves divide into external and internal branches, while the lower two sacral and the coccygeal nerve remain undivided. The external t/nnn-lics of the posterior divisions of the upper three sacral nerves form loops between themselves and the external branch of the last lumbar nerve on the back of the sacrum, and form a second series of loops on the posterior surface of the great sacro-sciatic ligament. From these loops are derived two or three nerves which pierce the glutens maximus muscle to supply the integu- ment. The internal branches of the posterior division of the upper three sacral nerves supply the multifidus spinaa muscle. The posterior divisions of the lower two sacral nerves form loops with the coccygeal nerve and the posterior branch of the third sacral nerve. Branches from these loops supply the skin over the coccyx. A careful study of the groups of muscles of the back will reveal the fact that their arrangement is simpler than is generally supposed. The five axo-appendicu- lar muscles i. e., the trape/dus, latissimus dorsi, levator anguli scapula?, and the two rhomboidei are well known. The two posterior serrati muscles are not readily forgotten. The deep cranio-vertebral group, the two recti and the two oblique muscles, are interesting and easily understood and remembered. The erector spinte muscle, with its three upward extensions, like a spreading vine, picking its way, hand over hand, as it were, from rib to rib, by regular intervals, is not difficult to master : The inner stem being the spinalis dorsi muscle, the middle consisting of the longissimus dorsi, the transversalis colli, and the trachelo- mastoid muscle ; and the outer stem being composed of the ilio-costalis, the acces- sorius ad ilio-costalem, and the cervicalis ascendens muscle. The complexus and the biventer cervicis really form but one muscle. The semi-spinales dorsi and colli muscles extending by long fibers from the transverse to the spinous pro- cesses, over a number of intervening vertebrae form really one long, slender group. The only group remaining is formed by the deep muscles which fill the posterior spinal groove; these extend between the spines (interspinales), between the transverse processes (intertransversales) from the dorsal aspect of the transverse processes of the thoracic vertebra? to the laminae just above (rotatores spins;), found only in the thoracic region, and similar but more extensive muscles having the same origins and going to the spines of the two or three vertebras above (multifidus spiiue muscle). M'2 SURGICAL ANATOMY. LIGA.MKXTs OF Till-: I '/;/,' 7V-; /,'/.'. I L COLUMN. Tlu 1 ligaments uniting the vertebra 1 may IK' divided as follows : Those con- necting tin- bodies; the lamina-; tin- spinous processes ; the transverse processes, and the articular processes of the vcrteline. The Ligaments which Unite the Bodies of the Vertebrae are the anterior and posterior common ligaments, the intervertebral discs, and the lateral vertebral ligaments. The anterior common ligament is a fibrous band which is situated upon the anterior surface of the bodies of the vertebra, and extends from the tubercle upon the anterior arch of the atlas to the front of the middle piece of the sacrum. Above, it is narrow and forms the central portion of the atlanto-axoid ligament. As it descends it broadens and forms a glistening white investment for the anterior surface of the bodies of the vertebra?. Below, it is attached to the front of the sacrum, and is lost in the periosteum of that bone. It is continued as the anterior sacro-coccygeal ligament. The ligament is composed of numerous fibers of various lengths. The most superficial fibers extend over four or five consecutive vertebrae, deeper ones over two or three vertebra', and the deepest connect adjacent vertebra;. The fibers of these different lengths are so interlaced that it is impossible to sepa- rate the ligament into these three sets of fibers. The ligament is closely attached to the intervertebral discs and the edges of the bodies of the vertebra;, but is not so firmly united with the intermediate portion of the bodies. It is thickest in the thoracic region, and in the lumbar is thicker than in the cervical region. The posterior common ligament is located upon the posterior surface of the bodies of the vertebra? and lines the anterior wall of the spinal canal. It extends from the basilar groove of the occipital bone to the coccyx ; is broader above than below, and thickest in the thoracic region : presenting opposite the intervertebral discs lateral expansions which give it a dentated appearance. Between the liga- ment and the middle of the posterior surface of bodies of the vertebne is an interval which is occupied by some areolar tissue and vessels to the bodies of the vertebne. The filum terminate of the spinal cord blends with the ligament at the back of the base of the coccyx. The more superficial fibers extend between three or four vertebne, and the deeper ones between adjacent vertebrae. The intervertebral substance or intervertebral discs arc twenty-three in number, situated between the adjacent surfaces of the bodies of the vertebra- from the axis to the sacrum. They are tough, elastic, and compressible, and form the chief bond of union between the vertebra 1 . In the sacral region they are more or less completely ossified. They are flattened or rather wedge-shaped, and their outline corresponds to that of the adjacent vertebral bodies. In the thoracic region PLATE CX. Posterior Common Lig. Inter-Vertebral Substance. Pulpy Centre. Anterior Common Lig Vena Basis Vertebrae. Spinous Process. Supra-Spinous Lig- Capsular Lig. Interspinous Lig. Ligamentum Subflavum. LIGAMENTS OF SPINAL COLUMN. 413 LIGAMKMV 01-' T1IH VERTEBRAL C'OLI'MX. 415 their thickness is nearly uniform, and the thoracic curve is chiefly formed by tin- bodies of the vertebra-, and in the cervical and lumbar regions their greater thickness in front assists in forming the curves of (hose portions of (he spinal column. They form about one-fourth of the length of the spinal column, and are thickest and largest in the lumbar region. When they are shrunken or compressed, as in old persons or laborers, the spinal column shortens and bends forward. They are composed of a firm ring of fibro-cartilaginous tissue and a central pulpy substance. The fibro-cartilaginous tissue is arranged in concentric lamiiue, the fibers of which pass obliquely from one surface of the disc to the other. The directions of the fibers of the two adjacent laminae are not parallel, but form angles like, the limbs of the letter X. The central substance of the discs is of a pulpy consistency, and is composed of a fine connective-tissue matrix which contains cartilage cells in its meshes. The lateral or short vertebral ligaments connect the adjacent margins of the bodies of the vertebra in the interval between the anterior and posterior common ligaments, with which they are continuous. They are best developed in the thoracic and lumbar regions. The Laminae are connected by the ligamenta subflava, The ligamenta subflava are found in the spaces between and connecting the lamina? of the vertebrae. The first of these ligaments extends from the axis to the third cervical vertebra, the two spaces above being filled by the posterior occipito- atlantal and posterior atlanto-axoid ligaments. The ligamenta subflava are attached, above, to the inner surface of the inferior articular process and the inner surface of the lower margin of the lamina of the vertebra ; below, to the inner surface of the superior articular process and the upper margin of the lamina. Each ligament extends from the articular processes of one side to those of the opposite side, forming one broad, short ligament. These ligaments assist in forming the capsular ligaments, which connect the articular processes and are continuous with the interspinous ligaments at the roots of the spinous processes. They are strongest in the lumbar region, of greater strength in the thoracic than in the cervical region, are composed of yellow elastic tissue, and assist in retaining the spinal column in the erect position. The Spinous Processes are connected by the supra-spinous and interspinous ligaments. The supra-spinous ligaments connect the tips of the spinous processes, and present the appearance of a strong, narrow, continuous band extending from the seventh cervical vertebra (vertebra prominens) to the spinous processes of the sacrum. They are continued upward as the ligamentum nuchse and downward along the spines of the sacrum. The downward continuation of the supra-spinous SURGICAL .\\.Crti.MY. ligaments closes in the lower end of the spinal canal, and is attached to the back of the coccyx. The interspinous ligaments are thin, membranous sheds which connect adjacent spinous processes of the vertebra?. The fibers of each ligament decussate. They arc stronger in the lumbar than in the thoracic region, and in the cervical region are delicate and supported by the interspinales mii-cles. The Transverse Processes are connected by the intertransverse ligaments. The intertransverse ligaments pass between the tips of the transverse pro- -e.s. In the thoracic region they are weak bands; in the lumbar region they are weak and membranous; and in the cervical region they are replaced by the intertransversales muscles. The Articular Processes are connected by capsular ligaments. The capsular ligaments connect adjacent articular processes and are attached along the margins of the articulating surfaces. Their inner portion is formed by the lateral part of the ligamenta subflava. In the cervical region they are loose; in the lumbar region not so lax ; and in the thoracic region short and tight. Kach joint is lined by one synovial membrane. MOVEMENTS. The spinal column is the axis of the skeleton; it supports the cranium, upper extremities, and part of the trunk, and is supported by the pelvis and lower extremities. It is composed of a number of bones, one superimposed upon another and bound together by numerous strong ligaments. When assisted b\- the surrounding muscles, it is capable of sustaining great weight, and by means of their elasticity the intervertible discs diminish or prevent the transmission of shock. Although the vertebnc are iirmly united and then.' is little movement between adjacent vertebra?, the spinal column is quite flexible and capable of many movements; these are possible on account of the elasticity of the inter- vertebral substance, and all occur around an axis which passes through the central pulpy substance of the intervertebral discs. The movements vary in different regions, and their freedom differs with the shape of the bodies, the articu- lar, transverse, and spinous processes. The bodies and intervening discs are the chief supports of the superimposed weight, and the articular processes, assisted by the ligaments between the spines and between the transverse processes, steady the column. The movements are flexion, extension, lateral flexion, cireumduc- tion, and rotation. In the neck there is little movement between the axis and the third cervical vertebra, but below this vertebra all movements are free in this region. Flexion is more limited than in the lumbar region. In the thoracic region there is slight movement, because of the obstruction offered by the ribs. PLATE CXI. Occipito-Atlantal Capsular I,iV. Anterior oblique Occipito-Atlautal Atlanto-Axoidean Capsular Lig. Anterior AtlantO' Axoidean Lig. Body of Axis Capsular Lig. between \ articular processes of I Axis and third [ Cervical Vertebra. I Superficial portion of Anterior Occipito- Atlantal Lig. Anterior Occipito- Atlantal Lig. Atlanto-Axoidean Synovial membrane. Anterior Common Lig. Short Vertebral Lig. ANTERIOR VIEW. Anterior Oblique or Lateral Occipito- Atlantal Lig. Posterior Occipito- Atlantal Lig. Posterior Arch of Atlas Lamina of Axis Posterior Atlanto- Axoidean Lig. Atlanto-Axoidean Capsular Lig. and Synovial Membrane. Ligamentum Subflavum. 27 POSTERIOR VIEW. OCCIPITO-ATLANTAL AND ATLANTO-AXOIDEAN LIGAMENTS. 117 LIGA.M]-:.\TS OF Till: VFAlTFAUtAL rul.l'MX. 41!) In the lumbar region all of the movements are comparatively free between the third and fourth, and fourth and tilth vertebra-. As the forms of the joints between the occipital bone, atlas, and axis differ from those of the intervertehral joints below, they require a separate description. The Axis is Connected with the Atlas by the anterior and posterior atlanto- axoid. two eapsuhir, transverse, and atlanto-odontoid capsular ligaments, and between them are two lateral and one central atlanto-axoid joint. The anterior atlanto-axoid ligament is a thin, fibre-elastic membrane. It is attached above to the anterior surface and lower border of the anterior arch of the atlas, and below to the base of the odontoid process and the transverse ridge on the front of the body of the axis. Its median portion is covered by the narrow upper end of the anterior common ligament, which, in this location, is sometimes called the superficial anterior atlanto-axoid ligament. On either side the atlanto- axoid ligament is continuous with the capsular ligaments. It is covered by the longus colli muscles. The posterior atlanto-axoid ligament is a thin membrane which takes the place of the ligamenta subflava in this location. It is attached above to the posterior surface and lower margin of the posterior arch of the atlas and below to the dorsal aspect of the superior margins of the lamina of the axis. On either side it extends to the posterior roots of the transverse processes, and is continuous with the capsular ligaments. It is covered by the rectus capitis postieus major and obliquns capitis inferioris muscles. The lateral atlanto-axoid joints are formed by the articulation of the superior articular processes of the axis with the inferior articular surface of the lateral mass of the atlas. Each joint, has a loose capsular ligament and one synovial sac. The ligaments are strengthened in front and behind by the anterior and posterior atlanto-axoidean ligaments. The central atlanto-axoid joint is divisible into two joints one between the odontoid process of the axis and the transverse ligament (syndesmo-odontoid) and the other between the odontoid process and anterior arch of the atlas (atlanto- odontoid). Each of these joints has a synovial membrane. The s} r novial sac of the syndesmo-odontoid joint is limited by a fibrous membrane which passes from the transverse ligament to the margins of the articular facet upon the posterior surface of the odontoid process and thus forms a capsular ligament. This synovial sac often communicates with the occipito-atlantal synovial sacs. The synovial sac of the atlanto-odontoid joint is supported by the atlanto-odontoid capsular liga- ment, which passes between the margins of the articular surface upon the anterior aspect of the odontoid process and those of the articular surface upon the internal surface of the anterior arch of the atlas. The atlanto-odontoid capsular liga- )_'() SURGICAL .-l.y ment is continuous with the occipito-atlantal eapsular ligaments. At thr margins of the uivh of ihe atlas it blends \vitli the central occipito-odontoid, anterior occipito-atlantal, and anterior atlanto-axoid ligaments. The transverse ligament is a strung, closely woven, fibrous band which passes across the large central opening in the arch of the atlas, and divides it into a small anterior portion through which the odontoid process projects and a large posti-rior part, which is the upper continuation of the spinal canal and transmits the spinal cord, its membranes, and the spinal portion of the spinal accessory nerves. I'pon each side the transverse ligament is attached to the tubercle upon the inner surface of the lateral mass of the atlas. A vertical band of fibers, placed immediately behind the transverse ligament, passes from the back- part of the base of the odontoid process to the occipital bone. This band is Mreiiglhened by fibers, some of which pass upward and others downward from the transverse ligament. The transverse ligament and the vertical band form a crucial ligament. The anterior surface of the transverse ligament is smooth and in relation with the syndesmo-odontoid synovial membrane. The lower margin of the ligament is closely apposed to the neck of the odontoid process and thus firmly suspends that process in place. MOVKMKNTS. The movements between the atlas and axis are necessarily chiefly in a rotatory direction. These movements are limited by the occipito-axoid (check) and the atlanto-axoid ligaments. The movement in the lateral atlanto- axoid joints is of a gliding character. There is also slight antero-posterior and lateral flexion. The Ligaments which Connect the Axis with the Occipital Bone are the occipito-cervical, crucial, and three odontoid ligaments. The occipito-cervical, cervico-basilar, or occipito-axoid ligament is the upper portion of the posterior common ligament, some of the fibers of which are not attached to the axis but pass upward to the occipital bont>. The ligament is attached below to the posterior surface of the body of the axis from the root of the odontoid process downward, and its lower attachment also extends to the upper part of the body of the third cervical vertebra. Above, it is attached to the basilar groove of the occipital bone. It is narrow at the body of the axis and gradually broadens above. It is in relation in front with the crucial ligament, and behind with the dura mater of the spinal cord, and is exposed by removing the spines and laminie of the atlas and axis. The crucial ligament is described with the transverse ligament. The odontoid ligaments connect the odontoid process with the occipital bone. They are three in number viz., a central and two lateral. The central odontoid ligament, or suspensory lii/mur//!, is attached below to the PLATE CXil. Posterior Common Lig. Cervico-Basilar Lig. Vertical Portion) of Transverse or I Crucial Lig-/ Atlanto-Axoidean Capsular Lig. Cervico-Basilar Lig Central Occipito-Odontoid Lig. Lateral Occipito- Odontoid Lig. Transverse Lig. Occipito-Atlantal Capsular Lig. and Synovial Membrane. Posterior Common Lig. LIGAMENTS IN POSTERIOR SURFACE OF UPPER PART OF ANTERIOR WALL OF SPINAL CANAL. Transverso-Odontoid Synovial Sac. Odontoid Process. Lateral Occipito- Odontoid Lig. Vertical Portion of Transverse or Crucial Lig. Atlanto-Odontoid Synovial Sac. Central Occipito- Odontoid Lig. Transverse Lig. CENTRAL ATLANTO-AXOID JOINT. 421 /.A/.u//-:.Y7N OF nil-: vr.nrr.nnM. COLUMN. 4-2:} tip of the odontoid process and above to the under surface of the anterior margin of tlie foramen magnum. It is a slender hand which is located between the two lateral odontoid ligaments. It is in relation in front with the anterior occipito- atlantal. and behind with the upper division of the crucial ligament. The lulu -it! iii/iiiitniil, nr dark, /!T/,V//r,l/, A y ATOMY. backward Mini forward. tints giving a limited nodding movement to tin- head. In more extensive forward MIK! backward movements of the head the cervical ])ortioii of the spinal column is flexed and extended. There is also a verv slight transverse and oblique gliding moveiiu'tit. I>i.n<>n Srri'LY. The Mood supply of the spinal column and its articulations is derived from the vertebral, occipital, ascending pharyngeal. ascending cervical, intercostal, luinhar. ilio-luniliar. sacra-media, and lateral sacral arteries. NKKVK SrriM.Y. From the spinal nerves. Fractures and dislocations of the vertebra are most common in the cervical and lumbar regions where mobility of the spinal column is greatest. If displace- ment exists, the spinal cord is compressed, lacerated, or pnlpiiied. Pressure upon or laceration of the motor tracts of the spinal cord causes loss of voluntary motion in muscles supplied by nerves which arise below the site of injury, because the motor cells of the cerebral cortex can not send impulses to the motor cells in or below the injured segments of the spinal cord. Sensation in the paralyzed parts is lost through involvement of the sensory tracts of the spinal cord and interruption of the impulses to the brain. Through pressure upon or rupture of the inhibitory nerves from the brain the relle.xes are not controlled and are much exaggerated unless the lumbar enlargement be destroyed. Pressure upon the inhibitory nerves for this reason causes priapism. Through pressure upon the trophic nerves nutri- tion of the skin is imperfect and bed-sores develop. Loss of trophic and motor impulses allows degeneration and atrophy of the muscles. Through pressure upon the sensory and motor tracts fullness of the bladder causes no reflex act, and reten- tion of urine results. After some time elapses the function of micturition may be performed through reflex action governed by the cells in the lower portion of the spinal cord. Paralysis of the sphincter ani causes incontinence of feces. DISSECTION. Having finished the study of the muscles of the back, the student should thoroughly clean the posterior aspect of the vertebra' from the skull to the base of the sacrum. In removing the muscles, care must be taken to avoid destroying the posterior divisions of the spinal nerves which supply them. The posterior wall of the spinal canal should then be removed in one piece. To accomplish this, place the body upon the table, face downward, the head hanging- over tin- edge, and a block under the abdomen : saw through the lamh:;c of the vertebrae. on each side close to the bases of the spinous processes from the third cervical to the last lumbar, inclusive. The ligaments between the spinous pro- cesses and between the lamina' of the second and third cervical, and between the PLATE CXIII. Posterior Longitudinal Meningo-Rachidean Veins. (Anterior Longitudinal \Meningo-Rachidean Vein. Vena Basis Vertebrae. Dorsi- Spinal Veins Posterior Longitudinal Meningo-Rachidean Vein Intercostal V. Anterior Longitudinal \\. Meningo-Rachidean Vein. Veins. Intervertebral Disc. Spinal Canal. Intercostal V. Vena Basis Vertebrae. (Anterior Longitudinal JMeningo-Rachidean Veins. SPINAL VEINS. 425 All TEH //>' A\D VEL\S OF Till'. 1 7.7/77-;/, 1 /,'.!/. COLUMN. 11 same portions dt' the last lumbar and first sacral verteline, should he divided with the knife, and the posterior wall of the canal lifted out. This will expose n (|iiantity of loose areolar tissue and fat which contains plexuses of veins and some small arteries. Carefully remove the areolar tissue and fat, The Spinal Arteries. The blood supply of the spinal column, spinal liga- ments, periosteum, and of the spinal cord and its membranes is derived from the spinal arteries which enter the canal through the inierverteliral foramina. The spinal arteries in the cervical region are derived from the vertebral, ascending cervical, and profunda cervicis arteries; in the thoracic region, from the dorsal branches of the intercostal arteries; in the lumbar region from the posterior brandies of the lumbar arteries; and in the sacral region from the lateral sacral arteries. The arrangement of the arteries after entering the spinal canal is similar in the different regions. Each spinal artery divides into three branches one of which passes to the vertebral arches and ligamenta subflava : another pierces the dura mater above the corresponding spinal nerve, and supplies the spinal cord and its membranes; and a third passes to the posterior surface of the bodies of the vertebra 1 . Tin 1 small plexuses of arteries seen on the posterior aspect of the bodies of the vertebra' are formed by the divisions of the third set of branches which anastomose with each other. These plexuses also give off branches which pass anteriorly around the wall of the canal to join branches from a median artery found on the posterior surface of the anterior common ligament, The Veins found Within the Spinal Canal are the meningo-rachidian and the medulli-spinal veins. The meningo-rachidian veins lie in the extra-dural fat, and are arranged in two plexuses one anterior and one posterior. The ante- rior plexus, of course, can not be studied until the spinal cord and its membranes have been removed from the spinal canal. It consists of two longitudinal veins which communicate freely with each other by means of transverse veins which pass beneath the posterior common ligament and receive the veins from the bodies of the vertebra? (venae basis vertebrae). The anterior plexus communicates with the basilar and occipital sinuses. Near the arch of the atlas it gives off a branch which forms the origin of the vertebral vein. Other branches are given off near the intervertebral foramina, and accompany the spinal nerves. The posterior longitudinal plexus consists of two longitudinal veins or channels, placed upon the inner surface of the lamina;. Branches pass freely from one channel to the other ; others pierce the ligamenta subflava to communicate with the dorsi-spinal veins ; while other branches pass forward to join the anterior plexus, thus forming a network which entirely encircles the spinal cord. The posterior plexus commu- nicates with the occipital sinus. The medulli-spinal veins are described with the spinal cord. SURGICAL ANATOMY. TIIK SPINAL CORD. The spinal cord (medulla spinali.-i is the continuation of the medulla oblon- gata. It extends from tin- lower border of the foramen magnum (below the deeussatiou of the pyramids of the medulla) to the level of the upper hurder <>f the second lumbar vertebra ; near its termina.tion it assumes a conic shape, the conus medullaris, and terminates in a slender thread, the filum terminate. In the fetus the cord extends the entire length of the spinal canal, hut does not in the adult, as the vertebral column prows more rapidly than the spinal cord. The length of the- spinal cord in the adult is from sixteen to eighteen inches. and its average weight is ahout one and one-half ounces. It is a somewhat flattened cylinder, wider in the transverse diameter. In the thoracic region, how- ever, it is almost cylindric in form. As it is lodged in the spinal canal, it follows the curves of the spinal column. It presents a cervical enlargement hot ween the third cervical and second thoracic vertebra-, and a lumbar enlargement between the ninth thoracic and the first lumbar vertebra. The former enlargement is widest opposite the sixth cervical, and the latter opposite the twelfth thoracic vertebra. These enlargements occur where the large nerves are given off to supply the extremities. The Membranes of the Spinal Cord. The membranes of the spinal cord are the dura mater, arachnoid, and pia mater. They are continuous with the corres- ponding membranes of the brain, and hold the same relation to each other as do those of the brain. The dura mater is a non-adherent, dense, fibrous sheath which surrounds the spinal cord. It differs from the dura mater of the brain in that it does not form the internal periosteum of the spinal canal, nor the fibrous septa fur the spinal cord ; it does not contain sinuses, nor adhere to the walls of the canal. Like the dura mater of the brain, the dura mater of the spinal cord sends over the nerves tubular prolongations which become continuous with their sheaths. The periosteum which lines the spinal canal is continuous with and represents the periosteal layer of the dura mater of the brain. The extra-dural veins of the spinal canal (meningo-rachidian) correspond in position to the sinuses of the dura mater of the brain. The dura mater is separated from the walls of the spinal canal by loose areolar tissue, fat, and the anterior and posterior plexuses of the extra-dural veins (meningo-rachidian). It extends from the lower margin of the foramen magnum to the back of the base of the coccyx, where it blends with the periosteum. It exists as an enveloping membrane only as far as the third sacral vertebra, beyond which it is impervious and exists only as a hollow, slender cord which surrounds the filum terminale. It is attached above to the margin of PLATE CXIV. SPINAL CORD AND MEMBRANES. 429 THK SIVXAL CORD. 431 the foramen magnum, to the axis, and third cervical vertebra; and below, to the posterior surface of the base of the coccyx. DissKiTiox. The spinal cord and its membranes should now be removed. To do this, divide the medulla, oblongata ami membranes of the cord at the fora- men magnum, and the spinal nerves as far outward in (lie intervertebral foramina as possible, so as to preserve the ganglia on their posterior roots. If the cord be perfect I v fresh, it should be hardened before its membranes are removed ; but if soft, it should be dissected in plenty of water, which will protect it from pulpefac- tion. Incise the dura mater near its termination, and open it along its posterior median surface with a pair of blunt-pointed scissors. Care must be taken to avoid injuring the subjacent arachnoid. Reflect the dura mater laterally, and note the shining, inner surface. Note also that the spinal nerves as they leave the cord are enveloped by prolongations of the dura mater. It will be seen that each nerve has a separate tubular prolongation of the dura mater, and that the anterior and posterior roots of the nerves are separated by a septum. The space exposed by reflecting the dura mater is known as the subdural space, and lies between the dura mater and the arachnoid. It is pro- longed for a short distance upon the roots of the spinal nerves. The arachnoid. The arachnoid is a thin, delicate, veil-like membrane which is continuous with the arachnoid of the brain, and lies between the dura and pia mater. It is more delicate than that of the brain, but resembles the encephalic arachnoid in sending tubular prolongations along the nerves. It is attached to the dura mater behind by prolongations of connective tissue. These trabeculae of connective tissue are not always demonstrable, and exist only in few and scattered places. Below it is prolonged upon tJie cauda equina. It will be noted that the arachnoid forms a long sac, the cavity of which lies between the arachnoid and the pia mater, and is known as the subarachnoid space. It contains the cerebro-spinal fluid, and is continuous with the sub* arachnoid space of the brain. To demonstrate this space, inflate it by injecting air into it through a blow-pipe inserted near the foramen magnum. This will illustrate the condition found in the congenital defect spina bifida, in which there is an overabundance of cerebro-spinal fluid with faulty development of the posterior wall of the lumbar portion of the spinal canal. In this condition the membranes are pushed through the opening in the spinal canal by the weight of the cerebro-spinal fluid which occupies the space now containing air. Through the foramen magnum the subarachnoid space of the spinal cord communicates with the corresponding space of the brain, and through openings in the posterior part of the fourth ventricle (foramina of Magendie, Key, and Retzius) the subarachnoid space of the brain communicates with the ventricles of the latter 432 SUUUK'AL ANATOMY. Pressure exerted upon (lie swelling of a spina biiida will at times cause slight bulging of the anterior fontanel. As the suharachimid space eomnmni- eates with the ventricles of the brain, opening a spina bifida may drain the cerebro- spinal thud from the brain and result in fatal convulsions. DISSECTION. Incise the arachnoid and reflect it from the underlying pia mater. This will open the subarachnojd space, which has just been inflated. It will be seen that the arachnoid is attached to the pia mater by numerous trahecuhe of subarachnoid tissue, and by three incomplete septa,- a posterior and two lateral, which not only attach the two membranes to each other, but at the same time divide the subarachnoid space into compartments. The posterior septum is placed opposite the posterior median fissure of the cord, and is less marked in the cervical region. It carries blood-vessels to the cord. The two lateral septa are formed by the ligamenta denticulata. The pia mater. The pia mater is a thin, delicate, vascular membrane which is continuous with the pia mater of the brain. It is closely adherent to the cord, and sends vertical partitions, or septa, into the anterior and posterior median fis- sures. Along the anterior median line of the cord the pia is thickened into a glistening band the Ihien ./.'!>. i:;;, tain motor libers ; tin: posterior ;itv sensory tiliers, and arise from the posterior horns. The liliers of the anterior root- emerge in several bundle- \vhieh are not placed in a single line : whereas the po.-trrior roots are larger, and their iiliers also emerge in several bundles, which form a single row at the postero-lateral fissure. These roots of the nerves pass along lor a varying distance within the dttral -heath of the cord, which intra-dnral portion of their course is called intra-thecal. The inti'ii-tlii'fiil cnin-xi' of the nerves is shorter above and longer below, as the upper spinal nerves pass transversely outward and the lower pass downward with increasing decrees of obliquity. As the cord terminates opposite the second lum- bar vertebra, the lumbar and sacral nerves and the coccygeal nerve have a longer intra-thecal course than those above. If the lumbar and sacral nerves are cut out with the cord, a condition similar in appearance to the under surface of a horse's tail will be seen, and hence the designation cumin r.!'. Direct Pyramidal Tract. NERVE-TRACTS OF SPINAL CORD. 441 Till-: SPINAL CORD. 443 spinal con! have a definite arrangement. Kach half of the spinal cord is divided into an antcro-laleral and a posterior tract l>y the postero-lateral fissure. The antero-lateral tract contains the direct pyramidal, crossed pyramidal, and direct cerebellar tracts, (lowers' tract, and the antero-lateral ground bundle. That portion of the antero-lateraJ tract which is in relation with the anterior median fissure is the anterior or direct pyramidal tract (column of Turck). It is the continuation of the anterior pyramid of the medulla, and contains those fibers which do not decussate in the medulla, though in all probability they do so in the cord by passing through the anterior commissure and thence to the crossed pyramidal tract of the opposite side. It tapers as it passes downward, and termi- nates in tin' middle of the thoracic region. It contains descending fibers i. e., libers in which nerve impulses descend. The crossed or lateral pyramidal tract contains the greater number of the libel's of the anterior pyramid of the medulla those which decussate. It passes downward into the posterior portion of the antero-lateral tract in front of and to the outer side of the posterior cornu. It contains descending fibers, and extends the whole length of the cord. The direct cerebellar tract lies between the lateral pyramidal tract and the surface of the cord, and does not extend further forward than that tract. It begins at the level of the root of the first lumbar nerve, ascends to form part of the resti- form body of the medulla, contains ascending fibers, and increases in size as it ascends. Gowers' tract, or the antero-lateral ascending tract, is a band of fibers on the surface of the cord in front of the direct cerebellar tract. It contains ascending fibers which enter the outer side of the tract of the fillet. The antero-lateral ground bundle comprises the remainder of the antero- lateral tract. This has been subdivided into the anterior ground bundle, the mixed lateral zone, and the lateral ground bundle. The anterior ground bundle is separated from the remainder of the antero- lateral ground bundle by the anterior roots of the spinal nerves and the anterior cornu. This division is hardly warrantable, as it contains fillers similar to those of the mixed lateral zone. Its fibers connect the cells of the anterior cornu. The mixed lateral zone is the backward continuation of the anterior ground bundle, and is limited behind by the crossed pyramidal tract. It contains both ascending and descending fillers which are connected with the cells of the anterior cornu. The anterior ground bundle and mixed lateral zone seem to be continuous above with the posterior longitudinal bundle of the medulla oblongata. The I//!/ ,-til i/rttuiid Imndle lies between the mixed lateral zone and crossed pyramidal tract externally, and the crescent of gray matter internally. Its ante- 444 SURGICAL AXATOMY. rior portion contains libers which arc connected with the anterior cornu, and its posterior portion has libers connected with the posterior eoriiu. The posterior tract of the white- matter of the cord is divided into two portions the columns of (loll and Bnrdach. These are :-e pa rated by a septum, and on the surface of the cord by a furrow. The column of Goll, or postero-internal tract, is in relation with the posterior median lissure. It contains ascending tibers which arc derived from the posterior roots of the nerves and others which connect the cells of the posterior cornu. Above, it is continuous with the posterior pyramid of the medulla. The column of Burdach, or postero-external tract, lies between the column of Goll and the posterior cornu. It contains ascending libers which are derived from the posterior roots of the nerves and others which are associated with the cells of the posterior cornu. Like the column of Goll, it is continuous above with the posterior pyramid of the medulla. The boundary zone of Lissauer is composed of the most external fibers of the posterior roots of the spinal nerves ; these libers ascending in that column or zone to enter the posterior cornu. The microscopic structure of the cord is not within the scope of this work, and is therefore not given. The Arteries of the Spinal Cord are the anterior spinal artery and the posterior and lateral spinal arteries which form upon the cord an anterior median and four postero-lateral arteries. The anterior spinal artery is a small branch which arises from the vertebral artery near its termination. It joins its fellow of the opposite side in front of the medulla oblongata, and forms a single median vessel which descends in front of the cord to its termination and for some distance on the filum terminate. It is joined on either side by branches from the lateral spinal arteries. This median vessel is lodged under the pia mater in the anterior median fissure, and supplies the cord and the cauda equina. The posterior spinal arteries are derived from the vertebral artery at the side of the medulla ; each artery passes to the side of the cord and divides into an anterior and a posterior branch, one branch running in front of the posterior roots of the spinal nerves and the other behind them. These arteries continue down the postero-lateral aspect of the cord to its termination. They are joined by the lateral spinal arteries and supply the adjacent cord, membranes, and cauda equina. The lateral spinal arteries in the cervical region are branches of the vertebral, ascending cervical, and deep cervical arteries ; in the thoracic region, of the dorsal branches of the intercostal ; and in the lumbar region, of the lumbar 7v//-; *rr\AL CORD. arteries. They enter the spinal canal through the intervertebral foramina, and divide into two branches one of which goes to the back of the bodies of the vertebras and the other reaches the cord upon the posterior root of a spinal nerve. Some of the latter branches join the anterior median artery while the others either terminate in the nerve root or join the postern-lateral arteries of the cord. They supplv the cord, its membranes, and the vertebra 1 . The Veins of the Spinal Canal and Spinal Cord are the dorsi-spinal, the meningo-rachidian, the vena; basis vertebra;, and the veins of the cord itself. All the veins of the spinal canal and spinal cord are devoid of valves. The meningo-rachidian veins have been described. The veins of the spinal cord (medulli-spinal) form a plexus over the surface of the cord within the pia mater, and emerge chiefly from the anterior and posterior median fissures. Branches from the plexus pass outward upon the nerve roots and communicate with the meningo-rachidian veins which in the upper part of the spinal canal empty into the vertebral and the inferior cerebellar veins or into the inferior petro.sal sinuses, and in the lower part of the canal into the inter- costal and lumbar veins. The Motor, Sensory, and Reflex Areas of the body governed by the spinal cord at different levels are approximately shown in the accompanying table from Gowers. While it is not my object to go into any details as to the structure or function of the spinal cord, it is perhaps well to say a few words upon the sub- ject. Thus, while most of the motor fibers cross at the decussation of the pyramids in the medulla, the sensory fibers cross in the cord throughout its entire length. This difference in the motor and sensory decussation is only anatomic, for from the functional standpoint they cross over upon the same principle /. e., practically upon their entrance into the cord : the motor fibers, with the exception of those of the direct pyramidal tract, entering above en masse, soon decussate in a body ; and the sensory fibers, entering at different levels, cross over soon after their entrance, thus decussating separately all along the cord. Reflex Action is a fanciful designation to indicate the centripetal impulse along a sensory nerve to the nerve center (gray matter) and the resulting centrifugal (return, reflected) impulse along a motor nerve. Thus, if a corn be stepped upon, the resulting excitation of the gray matter of the cord is so great that it promptly responds by a reflex motor impulse tending to withdraw the damaged part from the site of injury, even before the centripetal impulse reaches the brain and the individual becomes conscious of injury. This quick reflex act independent of conscious action is what is generally meant by reflex action, though all acts are reflex. Each portion of the spinal cord from which a pair of spinal nerves arise is IK; SURGICAL AXATOVY. termed M Moment, though, of course, there is no anatomic separation of the cord into these segments. Pathologic processes may involve one of these segments ; sncli a lesion is calldl a local lesion : a tumor would be an example of this. When one or more longitudinal tracts or systems of iihers are diseased the condition is designated a systemic disease; of this, loeomotor ataxia is an example. Disease of the Spinal Cord may all'ect its entire transverse area, or certain portions of it, in varying lengths ; or it may begin at any level, and thence extend upward or downward ; in that event being designated ascending or descending. Inflammation of the anterior horns of the spinal cord is a disease quite often seen in infants, and frequently overlooked ; its most constant symptom is paralysis of a group of muscles of the extremities; because of an infant's inability to walk, this symptom is not readily detected. The signs of lesions of the cord depend upon the area of gray matter or column of nerve fibers involved. Whether the symptoms be those of irritation or of paralysis depends upon the kind and degree of the pathologic process. An active congestion of the cord may cause symptoms of irritation, such as tingling, iibrillary twitching, and pains; while enough turgescencc and exudate to cause marked compression will result in numbness and motor paralysis. Passive congestions produce their most marked symptoms in the morning, because of the gravitation of venous blood to the cord during recumbency upon the back. All active inflammatory diseases of the spinal cord are aggravated by exercise, for the double reason that movements of the spinal column and functional activity of the cord increase the blood supply. Again, an intra-spinal tumor will, as it begins to encroach upon the cord, at first produce signs of irritation, and compression symptoms (paralysis or loss of function) will manifest themselves as the encroach- ment increases. Any disease involving the integrity of the entire transverse diameter of the cord will cause complete motor and sensory paralysis of the areas supplied by the part of the cord at and below the site of the disease. If the lesion affect only one lateral half of the cord, there will be motor disturbance on the same side of the body below the lesion and sensory disturbance upon the other side, which is accounted for by the different modes of decussation of the motor and sensory nerve fibers. No other affections of the body offer the same field for absolute accuracy in diagnosis and localization of lesions as do diseases of the spinal cord ; or, in fact, of the entire cerebro-spinal axis. A careful study of the areas of motor and sensory disturbance, together with the mode of onset and general course of the disease, usually leaves no room for doubt as to the location of the lesion, though its nature mav be doubtful. PLATE CX!X. Scapular Epigastric Abdominal Neck and Scalp Neck and Shoulder Shoulder Arm Hand Front of thorax Ensiform area Cremasteric Knee-joint Gluteal Foot clonus Plantar Abdomen (Umbilicus loth) Buttock, upper part Groin and Scrotum (front) outer side front Thigh inner side Leg, inner side Buttock, lower part Back of thigh v except part Sterno-mastoid ) 3 Trapezius , Diaphragm -| / Serratus f / berratus f , y the portion of the cord below the site of the Him7 thickened, brownish epidermis (keratu.-is i-enilis), particularly in persons much exposed to the weather. After middle life there is a tendency to dilatation of the superficial vessels, especially on the nose and cheeks. The absorption of the alveolar processes and loss of the teeth cause the charac- teristic appearance of the mouth in old age ; the lips being inverted, the red border becomes narrower, and when the mouth is closed the chin is drawn toward the nose. The more or less characteristic changes produced by disease can not, of course, be described here; allusion may be made to the waxy line of the skin in certain renal affections, the cyanosis in grave cardiac lesions, the hectic flush associated with pulmonary tuberculosis, and the "fades hippocratica." In the last named the sunken temples and cheeks ; the pointed nose and chin ; the dull, leaden hue : tin few drops of perspiration, and the cold, clammy skin portend the near approach of death. The supra-orbital arches are readily recognized as the dividing line between the forehead and the face. They are strong arches which form the upper boundary of the circumference of the orbit. They are covered by the eyebrows. Internally they end in the internal angular processes of the frontal bone, which articulate with the lacrymal bone and the nasal process of the superior maxilla. Between the two internal angular processes, at the fronto-nasal suture, a meningo- cele or an encephalocele sometimes appears. Externally, the supra-orbital arches terminate in the external angular processes, which articulate with the malar bone. Immediately below the supra-orbital arches are the eyes. They and their lids present points of interest. In size the eyes do not vary much in different indi- viduals, the apparent difference being due to the variations in the length of the palpebral fissure, which thus permits a larger or smaller portion of the ocular surface to come into view. The palpebral fissure is the aperture between the edges of the two lids, and extends from the inner to the outer canthus. The fissure is not, as a rule, exactly horizontal, the outer canthus being generally a little higher than the inner. By everting the eyelids, the tarsal cartilage may be felt as a thickened portion of the lid. The vertical arrangement of the Meibomian glands in the tarsal cartilage can also be made out. During sleep the eyeball turns upward and inward, thus sheltering the pupil behind the base of the upper lid under the supra- orbital arch, the lower lid, at the same time, moving upward and somewhat inward. In fainting spells, or during sleep, the white sclerotic of the eyeball shows through the palpebral fissure. This fact is often of value in detecting a sham sleep or a sham faint ; when, after gently lifting the upper lid by pressing upward and against the eyeball, if the pupil is in view, the patient is not asleep. 458 SURGICAL .I.Y.I TOMY. The puncta lachrymalia arc readily discernible near the inner canthus, the lower being the larger ami more c.xlcrnal. The introduction nf a probe into the lacrynial canaliculus should he preceded by drawing the lid outward, thus straightening the canal. The tendo oculi can be felt after drawing the eyelids outward, or forcibly clos- ing the eye. Immediately behind this is the laerymal sac. If a knife were pushed backward just below the tendo oculi it would enter the sac, with the angular artery and vein on the inner side of the puncture. A probe passing through this opening into the sac, and then downward, slightly outward, and backward, would enter the nasal duct and appear in the inferior meatus of the nose. Tension upon the tendon, as in closure of the eyelids, compresses the sac, with which it is closely connected, thus emptying the sac and forcing the tears which have collected at the inner angle of the eye down the nasal duct. The nasal duct extends from the inner angle of the eye to the inferior nasal meatus, just under the inferior turbinated bone. It is about three-quarters of an inch in length, and constricted in its middle. The lower opening in the nasal mucous membrane is a slit, but there is quite a large opening in the dry bone. When the lower end of the duct lies in the lateral wall of the meatus instead of in its roof, greater difficulty is experienced in passing a probe into the duct. The lower border of the orbit (infra-orbital margin) lies immediately below the eyeball and is formed by the superior maxillary and malar bones. It can be readily felt throughout its entire extent. The glabella is a flat, triangular eminence situated between the two internal extremities of the superciliary ridges. Immediately below the apex of the glabella is found the prominence of the nose formed by the nasal bones. The form of the nose and much of the general expression of the face are due to the size and form of the nasal bones. The difference in these bones accounts for the variations we find in the various races. In the Mongolian and Ethiopian the nasal bones are flat and broad at their base, and thus form the flat nose which is so characteristic of those races. In the Caucasian race, however, the nasal bones are narrow and elongated as well as prominent at the bridge. The nose is rigid at its root and base as far as its middle, beyond which it is cartilaginous and flexible. The intimate adherence of the skin to the nasal cartilages, which are attached to the lower ends of the nasal bones, makes furuncles or erysipelas in this region exceedingly painful, because of the lack of cutaneous elasticity. The lower end of the nose is open and divided into the two anterior nares by the nasal septum and the columna. It should not be forgotten that the nose is attached lower than the floor of its cavity ; so that it must be elevated when the interior is to be inspected. SURFACE ANATOMY OF THE FAt'K. Below the nose is seen the mouth, which is the upper opening of the gastro- intestinal tract. The lips contain muscles and vessels, and play a large part in the general expression of the face. In the living suhject the pulsations of the superior and inferior coronary arteries can ho easily felt by holding the lips between the linger and the thumb. In the operation for harelip these arteries are divided, the ensuing hemorrhage being easily controlled by pressure with the finger and thumb. Although the aperture between the lips is generally spoken of as the mouth, it must be remembered that the mouth extends backward from the lips to the pharynx. Below the lips can be found the prominence of the symphysis of the lower jaw. The lower jaw is easily felt from the symphysis to the condyle, where it articulates with the temporal bone. By slight pressure along the bone the alveolar border, in which the teeth are set, can be readily distinguished. In passing the finger backward along the lower border of the body of the jaw the angle, which is at the junction of the body with the ramus, can be distinguished. In front of the angle is a depression through which passes the facial artery, the pulsation of which can be detected in the living subject. The condyle of the lower jaw is felt in front of the tragus of the external ear and below the zygomatic arch. When the mouth of a living person is opened, the condyle can be felt leaving the glenoid fossa and advancing upon the eminentia articularis. This forward motion of the condyle affords a freer access to the external ear, which can be demonstrated by passing the little finger into the external auditory meatus and opening and closing the mouth. In the supra-orbital margin, at the junction of its inner with its middle third, is the supra-orbital notch, or foramen, which gives passage to the supra-orbital vessels and nerve. The mental foramen is found in the lower jaw, opposite the second bicuspid tooth ; it gives passage to the mental vessels and nerve. In a line drawn between the supra-orbital notch and mental foramen, and just below the infra-orbital margin, is the infra-orbital foramen, which gives passage to the infra- orbital vessels and nerve. These nerves are derived from the fifth cranial nerve. Quite frequently accessory foramina are found external to the constant ones, and usually transmit a portion of the nerve which commonly passes through the normal foramen. These anomalies, especially on account of their frequency, are of considerable significance in the treatment of neuralgias by nerve section. The anomalous openings occur most frequently in connection with the supra-orbital, the infra-orbital, or the mental foramen, in the order named, and upon the right side. At times a deep groove extends for several inches upward from the accessory supra- orbital foramen and about a finger's breadth internal to the temporal ridge. Failure to obtain relief in some cases of neuralgia, after section of the nerve which 460 SI'RGICAL ANATOMY. passes through the normal foramen, may he due to an accessory nerve, instead of to central disease or affections of the ganglia connected with the parent stem. Continuing outward from the external angular process is the zygomatic arch, formed l.y (lie malar hone and the zygomatic process of the temporal hone. The anterior part of the arch is Hat and hroad, and forms the prominence of the cheek, or the "cheek bone." Posteriorly, the zygomatic arch terminates in front of, and just above, the external auditory meatus. On account of the attachment of the dense temporal fascia to the upper border of this arch, the lower border is more easily distinguished. The zygomatic arch forms a dividing line between two depressions. These are generally filled with fat in the healthy individual, and, therefore, are not markedly evident. As soon as a wasting disease begins to tax the organism, the fat above the zygoma is absorbed, and this bony arch becomes much more prominent; as the wasting progresses, the masseteric depression can be plainly seen, and, at the same time, the fat in front of the anterior margin of the masseter muscle and below the anterior half of the malar bone disappears, with resultant sinking of the cheeks. The arteries of the face are the temporal, between the ear and zygoma, and the facial, on the body of the lower jaw just in front of the masseter muscle, at the angle of the mouth, and passing along the naso-labial fold and side of the nose to the inner angle of the eye. The facial vein runs straight across the face from the inner canthus of the eye to the anterior inferior angle of the masseter muscle at the lower border of the lower jaw. The anterior temporal and facial arteries are useful to the anesthetizer in studying the pulse, and also to the physician when the patient is sleeping. Expression is due to muscular traction upon the facial integument. In facial hemiplegia, when the muscles of the affected side have lost their power, expres- sion is gone, and the wrinkles of the face disappear. The " expression of the eye " is due to wrinkling of the lids and the peri-ocular integument. The study of the relation between facial expression and the permanent markings of the face resulting therefrom, as an index to character and disposition, is still in its infancy. Note the proximity of the muscle centers of the face in the ascending frontal and parietal gyri to the speech center. The latter is at the tip of the operculum around the ascending arm of the Sylvian fissure, and at the lower part of the ascending gyri. Just above it is the lip center, followed by that of the face, fingers, hand, and arm, with that of the lower limb overtopping all. Is this not also the order in which these muscle groups are involved during increasing animation accompanying a dis- cussion ? The central excitement becomes greater and extends over wider areas, sending larger and more intense impulses to those muscle bundles which traverse the facial integument and pull its surface hither and thither, forming wrinkles, PLATE CXXI. INCISIONS FOR DISSECTION. 461 Artery in superficial fasci PLATE CXXII. Superficial fascia Occipito-frontalis aponeurosis ./Pericranium/ / / Areolar tissue^ Outer table of skull D.ploe LAYERS OF SCALP. )ura mater CIRSOID ANEURYSM. 463 SCALP. Ki.-> dimples, scowls, and puckerings, expressive of the condition of the mind in relation to the nutter engaging it. The hahitnal recurrence of these emotional results leaves ii- impress hy gradually ondermining the elasticity of the skin involved and hy contracting the alleeted muscles, producing upon the individual's face indications of his character which may he read hy all who are competent. The external ear, or pinna, is placed at the junction of the face, neck, and cranial vault. The general conformation and direction of the pinna, and its utility for the collection and partial condensation of sound, need only he mentioned. During inspection of the tympanic memhrane and of the whole length of the exter- nal auditory canal, the direction of the latter concerns us practically. It is about an inch and a quarter long. When removing foreign hodies, which frequently lodge in this canal, it is important to note that it sags at its outer end, and can he straightened by pulling the pinna upward. The greatest diameter of the canal is vertical at the external end, and transverse at the internal. The upper and posterior portions of the tympanic memhrane incline outward. SCALP. DISSECTION. The dissection of the scalp should be made before that of the face and neck. The body should lie on its back, the head being well elevated by means of a large block placed under the nape of the neck. The head having been shaved, an incision should be carried from the root of the nose over the middle line of the vertex to the external occipital protuberance; and a second incision, at a right angle to the first, commencing at the nasal eminence, should extend on each side as far back as the ear. Beginning at the junction of the two incisions, reflect the skin backward and outward, forming two flaps. When dissecting these flaps great care must be taken to remove only the skin, the best guide being the bulbs of the hair, which are in the superficial fascia. The scalp is that portion of the cranial covering which lies in front of the superior curved ridges of the occipital bone and above the two temporal ridges, though in the dissection of the scalp, for convenience, the tissues in the temporal region are included. Layers. The scalp above the temporal ridges is made up of five layers viz., skin, superficial fascia, occipito-frontalis aponeurosis, loose areolar tissue, and peri- cranium (external periosteum). In the frontal and occipital regions, in place of the aponeurosis, are the muscular bellies of the occipito-frontalis muscle. Below the temporal ridges (in the temporal regions) the scalp is composed of eight layers 30 SURGICAL ANATOMY. viz., skin, superficial fascia, attolens and attrahens amvm muscles, occipito-fron- talis (epicranial) aponeurosis, arcolar tissue, temporal fascia, the temporal muscle, and the periosteum. That which is usually spoken of as the scalp includes the skin, the superficial fascia, and the OCClpito-frontalis muscle and aponciirnsis ; these three layers 'are closely adherent to one another. The skin of the scalp is thicker than thai of any other part of the body. By means of the superficial fascia the skin is closely adherent to the oceipito-fronlalis muscle and aponeurosis, which accounts for the movement of the skin with the muscle and its aponeurosis. It is rich in sebaceous glands which, when enlarged on account of occlusion of their duds, constitute sebaceous cysts or wens, so common in this region. These growths, even when large, except in very rare instances, are superficial to the oceipito-frontalis aponenrosis, and with care can. therefore, he removed without risk of opening the areolar tissue layer. The skin is well nourished by the vessels of the .superficial fascia. The superficial fascia of the scalp consists of but one layer, which presents a granular appearance, due to the nodulated fat and dense fibrous septa. Its septa firmly connect the skin to the oceipito-frontalis aponeurosis. In its density and capability of resisting pressure it is like the superficial fascia of the palm of the hand and sole of the foot. It is continuous behind with the superficial fascia of the hack of the neck ; laterally, and in front, with the superficial fascia of the face. It contains the principal blood-vessels and nerves of the scalp, in this respect differing from the superficial fascia elsewhere, with the exception of that of the face and ischio-rectal fossa?, the muscles of the auricle, and the hair-bulbs. The arteries of the scalp lie, as it were, in canals in the fascia, and are attached to the walls of these canals by loose fibrous tissue; when divided, they have a slight tendency to retract within these channels or canals, and, on account of the density of the fascia, it may he difficult to seize them with the artery forceps. Consequently, some form of pressure 1 is often employed to check the bleeding. The presence of the hair-bulbs in this dense fascia and their firm attachment to the scalp enable a strong person, by securely grasping the hair, to lift the entire weight of the body without tear- ing out the hair-roots. Owing to the density of the superficial fascia, redness and swelling are not very pronounced in inflammation of the scalp. The super- ficial fascia is thickest in the occipital region, and gradually grows thinner as it approaches the front and sides of the cranium. Wounds of the scalp bleed freely, because the arteries can not contract or retract on account of the density of the superficial fascia and their close adherence to the connective-tissue septa within which they ramify. DISSICCTIOX. Upon one side of the head the superficial fascia with the vessels PLATE CXXIII. Ante al a. Supraorbital a. Frontal a. Posterior temporal a. C/- ' . . 1 1 I Posterior auricular a. Occip SUPERFICIAL FASCIA OF SCALP, 467 and nerves are i<> be removed a.- one common layer, bringing into view the corre- sponding half of the occipito-frontalis aponeurosis and muscle; while upon tin- other side only the superficial fascia in the immediate neighborhood of the vessels and nerves is to lie removed, in this way exposing and giving a clear idea of the blood and nerve supply of the scalp. In reflecting the superficial fascia preserve the attolens and attrahens aurem muscles which lie between it and the aponeurosis. The Extrinsic Muscles of the Ear are very feeble and rudimentary, the auricle in man being practically immovable. They are three in number the attolens aurem, attrahens aurem, and retrahens aurem ; they require con>iderable care in dissection to avoid being overlooked and destroyed. DISSECTION. Draw the pinna downward and fasten it with hooks; this will make tense the attolens and attrahens aurem muscles. The attolens aurem, the largest of the three muscles, is broad and fan-shaped, converging to a narrow tendon below. It arises from the superficial surface of the occipito-frontalis aponeurosis below the temporal ridge, and is inserted into the cranial aspect of the upper part of the pinna. NKKVI; SKI-PLY. From the temporal branch of the facial nerve. ACTION. It draws the pinna upward. The attrahens aurem is the smallest muscle of the three, and arises from the occipito-frontalis aponeurosis in front of the attolens aurem muscle, and is inserted into the front of the helix. NI:I;VI: STPPLY. From the temporal branch of the facial nerve. ACTION. It draws the pinna forward and upward. DISSECTION. Release the pinna from its present position and draw it forward ; fasten it with hooks, and divide the integument over the tense band behind the auricle to expose the retrahens aurem muscle. The retrahens aurem muscle consists of two or three short muscular bundles which arise from the mastoid process of the temporal bone and are inserted into the back of the concha. NERVE Srppi.Y. From the posterior auricular branch of the facial nerve. ACTION. It draws the pinna backward. The Arteries of the Scalp are derived, in front, from the supra-orbital and frontal arteries ; on the sides, from the temporal ; and behind, from the posterior auricular and occipital arteries. The supra-orbital artery, a branch of the ophthalmic, leaves the orbit through the supra-orbital notch, and divides into a superficial and a deep branch, which ascend toward the vertex, anastomosing with the temporal and frontal arte- ries and with the supra-orbital' artery of the opposite side. It supplies the tissues of the forehead. 470 SURGICAL A \ ATOMY. The frontal artery, one of the two terminal branches of the ophthalmic, leaves the orbit at its inner angle and ascends on the forehead, anastomosing with the supra-orbital and with the frontal artery of the opposite side. The temporal artery, the smaller of the two terminal divisions of the exter- nal carotid, commences in the substance of the parotid inland and ascends over the posterior root of the zygoma, about two inches above which it divides into the anterior and posterior temporal ; in some cases it divides immediately after crossing the zygoma ; rarely, it divides below the zygoma. It is accompanied by branches of the facial and auriculo-temporal nerves. It is covered by the attrahens aurem muscle and crossed by one or two small veins. The temporal and anterior temporal arteries are the vessels used by the anesthetize!' to ascertain the character of the pulse. The (interior temporal artery passes forward in a tortuous course to anas- tomose with the supra-orbital and frontal arteries and with the anterior temporal artery of the opposite side'. It supplies the tissues along its course. It is the branch usually selected when blood is to Lie extracted from the arterial system. The /toalerior temporal artery, the larger of the two, passes upward and backward above the pinna and anastomoses with the posterior temporal artery of the opposite side and with the occipital and posterior auricular arteries. The transverse facial, anterior auricular, and middle temporal branches of the temporal artery will be described with the dissection of the face. The posterior the sinuses in the interior of the skull and with the veins of the diploi- l>y menus of till' emissary veins. The Nerves of the Scalp are branches of the trifaciul, facial, and great occip- ital nerves, and of the cervical plexus. The supra-orbital nerve, the larger of the two terminal branches of the frontal branch of the ophthalmic nerve, leaves the orbit with the supra-orbital artery through the supra-orbital notch or foramen, which is located in the upper margin of the orbit at the junction of its inner and middle thirds, and ascends upon the forehead beneath the orbicularis palpebrarum and the frontal belly of the occipito- t'rontalis muscle. It divides into two branches an inner and an outer and liecoines subcutaneous; the inner brand), the smaller, pierces the frontal belly of the occijiito-frontalis muscle and ascends as high as the parietal bone ; the outer branch, the larger, pierces the occipito-frontalis aponeurosis and ascends over the vertex as far as the occipital bone. The supra-trochlear nerve, the smaller of the two terminal brandies of the frontal branch of the ophthalmic nerve, appears at the inner angle of the orbit above the pulley of the superior oblique muscle, and ascends upon the forehead. It is covered by the orbicularis palpebrarum and frontalis muscles, piercing the latter to end in the integument. It supplies the skin of the forehead and the upper eyelid. Neurectomy. The supra-orbital and supra-trochlear nerves are often nilected by neuralgia, for the relief of which division or resection of these nerves may be required. The supra-orbital notch, if present, forms a sure guide to the position of the supra-orbital nerve, which can be reached and exposed by a vertical incision immediately over the notch, or by a transverse incision parallel to and a little below the eyebrow. The latter method, as it leaves a less noticeable scar, is the one more commonly practised. The former method, however, will expose a larger portion of the nerve. The skin having been divided by either a vertical or a transverse incision, the further dissection should be in a direction parallel to the fibers of the orbicularis palpebrarum muscle. The old subcutaneous operation is now seldom done on account of the extensive extravasation from division of the supra-orbital vessels. To divide the nerve well back in the orbit, it is necessary to sever the orbito-tarsal ligament and depress the orbital fat, when the nerve is sepa- rated from its connections and lifted on a blunt hook. The supra-trochlear nerve is exposed through an incision carried in a line drawn from the angle of the mouth through and beyond the inner canthus. The nerve will be found at the point of intersection of this line with the upper margin of the orbit. The occasional presence of an accessory supra-orbital foramen, giving passage to a division of the supra-orbital nerve, should not be overlooked. Recurrence of pain 176 SURGICAL ANATOMY. immediately after operation is good presumptive evidence of the existence of mi accessory foramen. Temporal branch of the orbital nerve. About an inch a hove the zygoma the temporal i'ascia is ]iierced by tlie temporal liraneli of the orbital branch of the superior maxillary nerve, which is distributed to the integument of the temple and communicates with the temporal branch of the facial nerve. The auriculo-temporal nerve, a branch of the inferior maxillary nerve. accompanies the temporal vessels, lying posterior to them. The auriculo-temporal nerve emerges from beneath the upper part of the parotid gland, and divides into two terminal branches the anterior and posterior temporal. The anterior temporal nerve, the larger, accompanies the anterior temporal artery to the vertex, and communicates with the facial and temporo-malar nerves. The posterior temporal nerve, the smaller, accompanies the posterior temporal artery. Temporal branches of the facial nerve extend upward over the zygoma upon the temple to supply the attrahens and attolens aurem, the orbicularis palpe- brarum, the frontalis, and the c-orrugator supercilii muscle. They communicate with tlie temporo-malar, auriculo-temporal, lacrymal, and supra-orbital nerves. The posterior auricular nerve, a branch of the facial, accompanies the posterior auricular artery, and, like the latter, divides into two branches a posterior and an anterior. The posterior (occipital) supplies the occipitalis muscle : the anterior (auricular), the auricle and the retrahens and attolens aurem muscles. This nerve is joined by filaments from the auricular branch of the pneuniogasirie nerve and from the great auricular and small occipital nerves. The small occipital nerve (occipitalis minor), a branch of the anterior division of the second cervical nerve, supplies the scalp behind the ear and over the occiput. It communicates with the great auricular and the great occipital nerve, and with the posterior auricular branch of the facial nerve. It can be seen in the neck running along the posterior border of the stemo-mastoid muscle. The great occipital nerve (occipitalis major), the largest cutaneous nerve of the scalp, accompanies the occipital artery over the occiput. It is the internal branch of the posterior division of the second cervical nerve; pierces the corn- plexus and trapezius muscles near their attachment to the occipital bone ; enters the superficial fascia with the occipital artery, and breaks up into a number of large branches which spread over the back of the head, supplying the integument as' far forward as the vertex. It communicates with the small occipital and the first cervical nerve, and receives a branch from the third cervical nerve. The Lymphatics of the Scalp follow the same course as the blood-vessels, which is the general rule. The posterior, or occipital, lymphatics enter the occipital glands situated along the origin of the occipitalis muscle ; the postero- PLATE CXXVI. r. of faciaM n. Iran. , Orbital a. Temporal br. of facial n. Temporal br. of o Supra' S u p r i Supratroc; Frontal a Angular a. I Posterior temporal a. Auriculo-temporal n. Superfical temporal v, Occipital a. Great occipital n. Small occipital n. Posterior auricular a. Superior coronary a) Inferior coronary a Infer ior labial a Facial a Fi Anterior auricular a. Middle temporal a. Parotid gland Supramaxillary br. of facial n. Stenson's duct Buccal br.of facial n. Infraorbital br.of facial n, Socia parottdis ARTERIES, NERVES, AND MUSCLES OF SCALP AND FACE, 477 M 'ALP. 17'.) > lateral, or posterior auricular, set enter (he posterior auricular glands situated upon (he niastoid attachiucnt of the sternomastoid niusele ; the temporal lyuiphalics enter the glands situated upon and within (lie parotid gland; and a frontal set end in (he facial lymphatics. In congestion of the scalp due to cold, and in other atfectioiis of this region which increase the activity of the lymphatics, these glands are considerably swollen and painful. The occipito-frontalis muscle and aponcurosis, exposed upon the side from which the superficial fascia has been removed, will now he studied. The occipito-frontalis is a broad, musculo-aponeurotic layer covering one side of the vertex of the skull from the occiput to (he brow. It consists of two flattened muscular bellies, an occipital and a frontal, with an intervening aponeu- rosis. The ncci/iifii! />i'/li/ (nirijiitfi/ix munch'), thin and quadrangular, arises from the outer two-thirds of the superior curved ridge of the occipital bone and the adjoining niastoid process, thus leaving a triangular interval between the two occipitales muscles as their fibers eventually meet higher up in the median line. The fibers are about an inch and a half in length and ascend to the aponeurosis. BLOOD SUPPLY. From the occipital and posterior auricular arteries. XKKVK SUPPLY. -The occipitalis muscle derives its nerve supply from the posterior auricular branch of the facial and, exceptionally, from the occipitalis minor nerve. The fntiital belly (frontalis muscle), a thin, muscular layer having intimate cutaneous connections, arises from the aponeurosis below the coronal suture. It descends over the forehead and blends with the orbicularis palpebrarum, the corru- gator supercilii, and the pyramidalis nasi muscle. BLOOD SUPPLY. From the frontal, supra-orbital, and anterior temporal arteries. NKKVE SUPPLY. The frontalis muscle derives its nerve supply from the temporal branch of the temporo-facial division of the facial nerve. The apftiifiirnxin extends over the vertex and is continuous across the middle line with the aponeurosis of the opposite side ; laterally it is continued over the temporal fascia to the zygoma, just above which it is attached to that fascia. Connected with the lateral portion of the aponeurosis are the attolens and attrahens aurem muscles. It is intimately connected with the skin through the attachment of the superficial fascia, and but loosely connected with the pericranium bv the connective tissue which intervenes, thus accounting for the movement of the integument when the occipito-frontalis muscle is in action. ACTION. Contraction of the anterior belly of the muscle elevates the eye- !>i' SURGICAL A^^'m.MY. Imnv and produces wrinkling of the forehead ; if contraction be continued, it draws the scalp forward, and pulls up the skin of the nose, to the extent even of moving the naso-lahial folds ; contraction of the occipital belly draws the scalp backward ; and alternate contraction of the two bellies niove< the scalp backward and forward. DISSECTION. Divide the aponeurosis in the median line, and make another incision at its junction with the frontalis muscle. Reflect the aponeurosis outward and backward, and the frontalis muscle downward. Areolar tissue layer. The mobility of the scalp depends entirely upon the laxity of the subjacent areolar tissue layer: it is this layer which permits ex- tensive Haps of the scalp to be torn loose. When the hairs become caught in moving machinery the entire scalp may be torn off, laying this tissue bare. It was due to the laxity of this layer that the American Indian, with no knowl- edge of anatomy or surgery, was able to peel off the scalp with so much ease. Exposure of the skull in a postmortem examination is effected by peeling off the seal]) along this layer of tissue, and it is remarkable with what ease the skull can thus be exposed. To further illustrate the laxity of this tissue, it will suffice to relate a case mentioned by the late I). Hayes Agnew : A midwife attending a woman in child-birth incised the child's scalp, thinking it the protruding bag of waters. Labor pains came on, and the head protruded through the scalp wound with the entire vault of the skull laid bare. Tumors. By careful examination tumors situated above the occipito-frontalis aponeurosis or in it will be seen to be freely movable. All immovable growths of the scalp should be most carefully examined before extirpation, for they are probably beneath the aponeurosis ; a tumor originating within the cranium may force its way outward and form a prominence on the scalp. Wounds involving only the skin and superficial fascia of the scalp, when the occipito-frontalis muscle or its aponeurosis has not been divided, do not gape, because of the close adherence of the skin to the superficial fascia and of the superficial fascia to the aponeurosis. The areolar tissue layer permits of wide separation of the edges of a wound which divides the occipito-frontalis aponeu- rosis. Antero-posterior wounds which involve the aponeurosis gape but little, while the edges of transverse wounds are widely separated by the contraction of the occipito-frontalis muscle. The great vascularity of the scalp lessens the likeli- hood of sloughing and gangrene. A large flap of the scalp attached by but a small pedicle is much less likely to perish than a flap of skin torn from another part of the body, as the vessels of the scalp run immediately beneath the skin and are included in the flap. In phlegmonous erysipelas and in deep inflam- mation of the scalp the areolar tissue layer becomes infiltrated with pus and conse- quently sloughs. As the vessels are superficial to this layer the skin does not M '. I LP. 1 8 1 necrose, ulcerate, and allow pointing, and for this reason it is important to incise early. The pericranium (external periosteum) is but loosely attached to the bone, except at the sutures, where the union is firm. In lacerated wounds of the seal]) the pericranium is frequently stripped from the skull to the extent of exposing large areas of bone. The pericranium differs in its functions from the periosteum covering other bones in that, if the periosteum be removed to any extent from another hone, the part of the bone from which it is removed will most probably necrose, while the pericranium may be stripped from a considerable part of the vault of the cranium without necrosis following. This is due to the 1 fact that the bones of the skull receive their blood supply chiefly from the vessels of the exter- nal (endosteal) layer of the dura mater, while the other bones are nourished to a great extent through their pcriosteal covering. The pericranium at the sutures becomes continuous with the external layer of the dura mater, constituting the so-called intersutural membrane. It is also continuous with the dura at the for- amina ; hence it is that inflammation of the pericranium may extend by continuity and involve the dura mater, producing pachymeningitis. Collections of blood or pus in the scalp may he situated superficial to the occipito-frontalis aponeurosis, between the aponeurosia and the pericranium or beneath the pericranium. A collection superficial to the aponeurosis is of but little moment, since the density of the superficial fascia causes it to be circum- scribed. Collections in the areolar tissue layer, between the aponeurosis and the pericranium, are limited only by the attachments of the occipito-frontalis muscle and its aponeurosis; thus they may undermine the entire scalp and prove serious if not evacuated early. Collections beneath the pericranium are limited to a single bone, on account of the sutural attachments of the membrane. Collections in the areolar tissue layer call for drainage, and should they be slow in healing, the scalp must be firmly bandaged in order to arrest the movements of the occipito- frontalis muscle. Hematomata in the areolar tissue layer are uncommon, except as a result of fissured fracture of the skull with rupture of one of the branches of the middle meningeal artery, or of the superior longitudinal or lateral sinus, as the areolar tissue between the aponeurosis and the pericranium contains but very few vessels. Collections of blood beneath the pericranium, generally termed cephalhematomata, must be limited to one bone, since the membrane dips into the sutures and becomes continuous with the dura mater ; they are usually congenital and due to pressure upon the head at birth. In septic inflammation of the scalp infection may reach the superior longitudinal sinus through the parietal emissary vein and the lateral sinus through the occipital and posterior auricular veins and their communications with 31 482 SURGICAL AXATO.MY. the mastoid vein which empties into the lateral sinus. Through the anastomo-t - between the diploic veins and the veins of the pericranium septic material in the scalp may ivaeh thr sinus ahe parvie and the cavernous sinus through the fronto- sphenoid diploic vein, the superior petrosal sinus through the anterior temporal diploic vein, and the lateral sinus through the posterior temporal and occipital diploic veins. In erysipelas, abscess, and other infectious inflammations of the scalp germs may enter the sinuses through these various routes and cause throm- bosis, embolism, and pyemia. Temporal fascia. The temporal fascia is a white, shining membrane, which is stronger than the occipito-frontalis aponeurosis in this location, and which gives attachment by its under surface to the superficial fibers of the temporal muscle. Above, it is attached to the entire extent of the temporal ridge as a single layer; while below, it divides into two layers, the outer of which is attached to the external and the inner to the internal border of the upper margin of the zygo- matic arch and zygomatic process of the malar bone. Between these two layers are seen a small <]uantity of fat, the orbital branch of the middle temporal artery, and the temporal branch of the temporo-malar or orbital branch of the superior maxillary nerve. In relation with its outer surface is the extension of the occipito- frontalis aponeurosis, the orbicularis palpebrarnm, the attolens and attrahens aurem muscles, the temporal vessels, the auriculo-temporal nerve, and the temporal branches of the orbital and facial nerves. Immediately above the zygoma it is pierced by the middle temporal artery, a branch of the temporal. Density of the temporal fascia. Owing to the density of this fascia abscesses beneath it very rarely point upon the surface, the pus passing in the direction of least resistance namely, through the pterygo-maxillary region into the mouth or neck. Its unyielding nature is well illustrated by a ease recorded by Denonvilliers : "A woman who had fallen in the street was admitted to the hospital with a deep wound in the temporal region ; a piece of bone several lines in length was found loose at the bottom of the wound and was removed. After its removal the finger could be passed through an opening with an unyielding border, and came in contact with some soft substance beyond. The case was considered one of com- pound fracture of the squamous portion of the temporal bone, with separation of a fragment and exposure of the brain. .A bystander, however, noticed that the bone removed was dry and white. A more thorough examination of the wound revealed the fact that the skull was uninjured, that the supposed hole in the skull was merely a laceration of the temporal fascia, that the soft matter beyond was muscle and not brain, and that the fragment removed was simply a piece of bone, which, lying on the ground, had been driven into the soft parts when the woman fell " (Troves). PLATE CXXVII. Supraorbital a Supraorbital n. Frontal a. Infraorbital br.of facial n. Temporal br. of orbital n. Malar br.of facial n. Temporal br.of facial n. Temporal fascia Infratrochlear n. Nasa n I Auriculo-temporal n. Middle temporal a. Anterior auricular a. w X Superficial temporal v. ^Superficial temporal a. ^Facial n. -Posterior auricular a. Internal maxillary a. Buccal br.of facial. n. Inframaxillary br.of facial n. Mental n Mental a. Labial br\ Facial v. Facial a. Infraorbital n. 'Palpebral br. Infraorbital a. Nasal br. 'Supramaxillary br.of facial n. Transverse facial a. TEMPORAL FASCIA AND NERVES OF FACE. 484 PLATE CXXVIII. Temporal m. Superficial temporal a. Facial n. Internal maxillary a. Temporo-maxillary v. Masseter m. Platysma myoides m. TEMPORAL MUSCLE. 485 PLATE GXXIX, INCISIONS FOR DISSECTION AND LINES FOR VESSELS AND NERVES. 487 FACE. 489 DISSECTION. The temporal fascia should now be detached from the /ygomatic arch and reflected upward, wlien the greater portion of the temporal muscle and a quantity of fat overlying the muscle above the zygoma will be exposed. The tendon of insertion of the muscle will be seen in dissecting the face. The temporal muscle, broad, flat, and triangular, is situated on the side of the head, and occupies the temporal fossa. It arises from the under surface of the temporal fascia and from the whole of the temporal fossa, whence its libers descend and converge to a tendon which passes under the zygornatic arch to be inserted into the apex, the inner surface, and the fore part of the coronoid process of the lower jaw down to the last molar tooth. BLOOD SUPPLY. From the middle and deep temporal arteries. NEK VK SUTLY. Derived from the temporal branches of the inferior ma.i-illary in i'/ 1 . ACTION. The action of the temporal muscle is to elevate the lower jaw ; its posterior fibers also assist in drawing the lower jaw backward after other muscles have carried it forward. FACE. DISSECTION. The dissection of the face should follow that of the scalp. The head should be placed in the same position as for the dissection of the scalp, but slightly lower, and turned so that the side of the face to be dissected is upward. The cheeks and nostrils should be distended with cotton or oakum and the lips sewed together. The muscles and vessels should be dissected on one side of the face and the nerves on the other. The incisions are made as follows: The first incision is made from the nasal eminence along the median line of the nose, around the aperture of the nostril, along the median line of the upper lip, around the mouth along the line where the skin joins the mucous membrane to the median line of the lower lip, and thence to the point of the chin. A second incision is carried along the lower border of the jaw to the angle of the jaw, then upward to the lobe of the ear. Reflect the skin outward. The facial muscles (muscles of expression) are inserted partly into the skin, and great care must be taken that they are not removed with the skin. The skin of the face is remarkably thin, and freely supplied with vessels and nerves. On account of the free blood supply it is a common site of nevi, except over the chin, where it is peculiarly dense and adherent to the parts beneath. The skin covering the eyelids and the bridge of the nose, owing to the presence 4 !>0 SURGICAL A ^ ATOMY. of a layer of lax cellular tissue, is luoselv aillicreiit t<> the parts beneath. Over the cartilages of the nose the skin is so intimately adherent to the tissues beneath that it is removed with difficulty. It is very freely supplied with sebaceous and sudor- iferous glands, and hence is commonly the site of acne and eruptions which especially involve the seha-ceous follicles; it is also the site of sebaceous tumors. Facial abscesses usually point quickly and seldom attain large size. The superficial fascia the cellular tissue layer of the face contains a con- siderable amount of fat, except in the eyelids and over the bridge of the nose. The laxity of the cellular tissue favors the spreading of infiltrations, so that the cheeks and other parts of the face may become greatly swollen. In general dropsy the face soon becomes puffy, the edema first appearing, as a rule, in the lax areolar tissue of the lower eyelid. The soft tissues of the cheek favor the spread of destructive processes. In cam-rum oris a form of gangrene of the mouth attack- ing the young the whole cheek may be lost in a few days. (Ireat contraction is apt to follow upon loss of substance, so that the jaw may be firmly closed in some cases, as is seen a ft el' recovery from deep ulceration (Treves). The mobility of the tissues of the face renders this region favorable for the performance of plastic operations, and their vascularity insures a prompt and perfect union. Notwith- standing the fact that there is a large quantity of fat in the subcutaneous tissue, fatty tumors are rarely seen in this region. The thickness of the tissues of the cheeks and lips favors the embedding of foreign substances in these parts. Thus, a tooth which has been knocked out has remained embedded in the lip. Henry Smith reported a remarkable cast' in which he removed a piece of tobacco-pipe three inches long from the cheek, where it had remained for several years. DISSECTION. The superficial fascia underlying which are the muscles, vessels, and nerves should be removed in the same manner as the skin, taking- care not to disturb the muscles. As the superficial fascia is not easily removed in a continuous layer, it may be taken away in sections, the dissection being made in the line of the muscular fibers ; this is necessary, too, in order to avoid dividing the blood-vessels and nerves of the face. The removal of the fascia in this manner exposes the muscles, the vessels, and the nerves. The Muscles of the Face (muscles of expression) are divided into three groups : those of the nose, those of the eyebrows and eyelids, and those of the mouth i. p., nasal, palpebral, and oral. The Muscles of the Nose are the pyramidalis nasi, the compressor nasi, the levator labii superioris alseque nasi, the dilator naris, and the depressor a la.- nasi. The pyramidalis nasi muscle covers the nasal bone, and is continuous above with the frontalis muscle, where it is attached to the deep surface of the inter- superciliary integument. It arises from the aponeurosis over the cartilage of PLATE CXXX. Pjramidahs nail m. Orb.cularis palpebrarum m. Frontalis m. - apor.euros.s Attrahens aurem m. ttollens auiem m. Retrahens aurem m. Occipitalis m. Depressor anguii oris m. MUSCLES OF FACE AND SCALP. 491 tysma myoides m. FACE. la- the nose, where it joins the lower edge of the nasal bone and the compressor nasi muscle. NKKVK STPPLY. From tlie infra-orbital branch of the temporo-facial division of the facial nerve. ACTION. It renders the skin over the cartilages tense, and that over the root of the nose lax. thus forming the transverse crease at the root of the nose. The compressor nasi muscle is triangular in shape, arises by its apex from the canine fossa of the superior maxillary hone, and ends in the aponeurosis covering the cartilaginous part of the nose, blending with the corresponding muscle of the opposite side. The origin of this muscle is concealed by the levator labii superior!* aheque nasi muscle. NF.KVE STPPLY. From the infra-orbital branch of the upper division of the facial nerve. ACTION. It throws the skin at the side of the nose into vertical wrinkles, aids in the elevation of the upper lip, and slightly compresses the cartilaginous ridge of the nose. When the compressor nasi muscle is reflected from the median line outward, the superficial branch (naso-lahial) of the nasal nerve, which becomes subcutaneous between the nasal bone and the lateral nasal cartilage, will be seen running down- ward to the tip of the nose. The levator labii superioris alaeque nasi muscle, placed by the side of the nose and overlapping the origin of the compressor nasi muscle, arises from the upper part of the nasal process of the superior maxilla. It descends, and divides into two portions : the inner and smaller part is inserted into the inner side of the ala nasi, and the outer into the upper lip, blending with the orbicularis oris muscle. It is partially overlapped near its origin by the orbicularis palpebrarum muscle. NERVE SUPPLY. From the infra-orbital branch of the facial nerve. ACTION. It raises the inner half of the upper lip, and draws outward the wing of the nose, thus dilating the anterior naris. The dilator naris muscle consists of two portions an anterior and a posterior. The anterior portion is a thin fasciculus which passes from the lower edge of the cartilage of the wing of the nose to the integument over the ala ; the posterior portion arises from the margin of the nasal notch of the superior maxilla and from the outer surface of the sesamoid cartilages of the nose, and is inserted into the skin over the back and lower margin of the ala of the nose. NERVE SUPPLY. From the infra-orbital branch of the facial nerve. ACTION. It enlarges the anterior naris by raising and everting its outer edge, thus counteracting its tendency to be closed by atmospheric pressure. In condi- tions occasioning dyspnea e. g., laryngeal or tracheal obstruction the action of !'.U SURGICAL A \ATOMY. these muscles can plainly he seen, and constitutes one ol' the signs which indicate tracheotomy or intubation. The depressor alae nasi is a short. Hat muscle which may lie exposed when the upper lip is everted and its mucous membrane removed from the side of the labial frenum. It arises from the incisive fossa of the superior maxilla, whence its fibers ascend to be inserted into the septum nasi and the posterior lower part of the wing of the no NICRVK SUPPLY. From the buccal branch of the cervico-facial division of the facial nerve. ACTION. It draws downward and inverts the edge of the nasal cartilam .-. The Muscles of the Eyelids and Eyebrows are the orbicularis palpebrarum, the corrugator supercilii, the levator palpebrse superioris, and the tensor tarsi. Tendo oculi (tendo palpebrarum). Before examining the orbicularis palpe- brarum the tendo oculi (internal tarsal ligament) is to be noted. It is a short tendon, about one-sixth of an inch in length by one-twelfth of an inch in breadth, and can readily be felt at the inner angle of the eye after drawing the eyelids outward. It is attached to the nasal process of the superior maxilla in front of the lacrymal groove, passes transversely outward in front of the lacrymal sac, and divides into two portions, separated by the caruneula lachrymalis ; the upper portion is attached to the inner extremity of the upper, and the lower to the inner extrem- ity of the lower, tarsal cartilage. As the tendon crosses the lacrymal sac it gives off a strong aponeurotic lamina, which covers the sac and is attached to the margin of the lacrymal groove. This expansion will be seen on reflecting that portion of the orbicularis palpebrarum muscle which covers the lacrymal sac. To puncture the lacrymal sac a knife is inserted below the tendo oculi in a direction downward and a little backward, dividing the skin, the orbicularis palpebrarum muscle, and the fibrous expansion derived from the tendo oculi. The angular artery and vein are situated on the inner side of the incision. The external tarsal ligament extends, undivided, transversely inward from the edge of the frontal process of the malar bone to the adjacent outer extremities of the two tarsal cartilages. The orbicularis palpebrarum (orbicularis oculi, sphincter oculi) is a thin. broad muscle which surrounds the margin of the orbit and the eyelids, forming a sphincter ; it is continuous, above, with the fibers of the frontalis muscle. It arises from the internal angular process of the frontal bone, the nasal process of the superior maxilla, the tendo oculi, and the lower margin of the orbit. From this origin the fibers are directed outward, forming a series of oval curves which cover the eyelids, surround the margin of the orbit, and spread over the forehead. temple, and cheek. The central fibers, occupying the eyelids and connected inter- PLATE CXXXI. Pulley Superior rectus m. Tendon of superior oblique m Orbital fat Inferior rectus m Inferior oblique m Corrugator Supercilii m. Puncta lachrymalia Meibomian gland Conjunctiva Tensor tarsi m. TENSOR TARSI AND CORRUCATOR SUPERCILII MUSCLES. 496 FA el-:. -Jit? nally with the tendo oeuli and externally witli the external tarsal ligament and the malar bone, constitute tln.Q palpebral portion of (lie muscle. The libers of this portion, which are in immediate relation with the eyelashes, have been docrilied as the i-Hliii-i/ muscle; but this, however, must not be confounded with the ciliary muscle proper the muscle of visual accommodation. More peripheral fibers con- stitute the oi-tilfiil /I'nii'iii of the muscle. The latter arise from the internal angular process of the frontal bone and from the nasal process of the superior maxillary bone, and are distributed around the margin of the orbit. They are continuous above with the frontalis and corrugator supercilii muscles, and extend outward upon the cheek to mingle with the elevators of the upper lip and nose and with the zygomaticus minor muscle. NKKVE STPPLY. From the temporal and malar branches of the temporo-facial division of the facial nerve ; hence in paralysis of this nerve the eyelids on the paralyzed side can not be closed. ACTION". The orbicularis palpebrarum muscle closes the eyelids and protects the eye. The palpebral portion of the muscle contracts during winking. Con- traction of the orbital portion presses the eyeball backward into the orbit and draws the soft parts covering the margin of the orbit around the eyeball, thus protecting it from injury. While this cushion of tissue may be severely bruised, as is seen in a "black" eye, the eyeball itself is rarely injured. As the outer portion of the orbicularis is mingled with the fibers of the frontalis muscle and the elevators of the upper lip and nose, slight depression of the eyebrow and elevation of the upper lip and of the wing of the nose follow contraction of this portion. Strong contraction of the entire muscle holds the eye firmly in the orbit, thus protecting it against the severe strain in violent coughing, sneezing, and vomiting, during which acts the muscle usually contracts spasmodically. Contraction of the palpebral portion of the muscle following that of the orbicular portion tends to draw the lids slightly inward, thus directing the tears to the inner angle of the fissure between the eyelids, near which are situated the puncta lachry- malia. The tensor tarsi (Homer's muscle) is a small muscle, really a deep portion of the orbicularis palpebrarum, situated at the inner angle of the orbit behind the tendo oculi. To expose it it is necessary to cut perpendicularly through the middle of the upper and lower eyelids, when the nasal half of each lid should be reflected inward and the mucous membrane removed. The muscle will be seen to arise from the ridge on the lacrymal bone. It passes outward behind the lacrymal sac and divides into two portions which cover the posterior aspect of the canaliculi. The two portions terminate in the inner ends of the upper and lower tarsal cartilages near the puncta lachrymalia. 32 SURGICAL A\ ATOMY. NHIVK SrrpLY. From tin- infra-orbital branch of the temporo-facial division of the facial nerve. ACTION. It compresses the lacrymal sac. The corrugator supercilii muscle arises from the inner end of the superciliary ridge of the frontal hone. Its lihers are directed outward and a little upward to the under surface of the orhicularis palpebrarum and frontalis muscles, to he inserted into the former over the middle of the supra-orbital arch. XKRVE SUPPLY. From the temporal hranch of the temporo-facial division of the facial nerve. ACTION. It draws the eyebrow downward and inward, thus making the vertical wrinkle of the forehead at the inner extremity of the eyebrow. DISSECTION. The nasal half of the orhicularis palpebrarum and a small part of the frontalis muscle having been reflected inward, the corrugator supercilii is exposed. The levator palpebrae superioris muscle. By reflecting the outer as well as the nasal half of the orhicularis palpebrarum muscle, and detaching the orbit o- tarsal ligament from the superior orbital margin and reflecting the ligament downward, the insertion of the levator palpebraj superioris muscle by a broad aponeurosis into the upper border of the tarsal cartilage of the upper eyelid can be seen. The Muscles of the Mouth are the orhicularis oris, the levator labii supe- rioris, the levator anguli oris, the zygomaticus major, the zygomaticus minor, the buccinator, the risorius, the depressor labii inferioris, the depressor anguli oris, and the levator labii inferioris. The risorius muscle (Santorini's muscle), a part of the platysma myoides, consists of a thin bundle of fibers which arises from the fascia covering the masseter muscle and parotid gland, and passes horizontally forward to the angle of the mouth, where it joins the fibers of the orbicularis oris and depressor anguli oris muscles ; some of its fibers pass to the skin at the angle of the mouth. NERVE SUPPLY. From the buccal branch of the lower division of the facial nerve, which enters it from beneath. ACTION. It retracts the corner of the mouth. Its contraction during certain conditions, as in tetanus, causes the " risus sardonicus" of the old authors. The orbicularis oris muscle (sphincter oris), nearly an inch in breadth, sur- rounds the mouth, forming a sphincter ; at its periphery it unites with several muscles which act upon that aperture. It consists of two parts an inner, central, or labial part, and an outer, peripheral, or facial part ; the two differing in appear- ance and in the arrangement of fibers, like the orbicularis palpebrarum muscle. The inner, central, or labial portion consists of pale, thin fibers, fine in texture, FA f the lips, and has no bony attach- ment, hut is continuous around tlic angles of llie mouth from one lip to the other. The outer, peripheral, or faeial part is thinner and wider than the lahial, and has a bony attachment as well as eonnection with the adjacent muscles. In the upper lip the orhicnlaris oris mnscle is attached at each side of the middle line to the lower part of the septum nasi by naso-labial slips, and to the alveolar border of the upper jaw opposite the incisor teeth ; in llie lower lip it is attached to the alveolar border of the lower jaw opposite the canine teeth by a single fasciculus (nmscnli iucisivi). The cutaneous surface of the muscle is intimately connected with the skin of the lips and surrounding parts. The intimacy of this union is so great in some instances that the mouth is surrounded by radiating wrinkles, especially marked in the upper lips of women. The labial integument of the male probably contains fewer wrinkles on account of the presence of large hair-bulbs. The deep surface of the orbicularis oris is covered by mucous membrane, between which and the muscle, in the submucous tissue, are the coronary arteries and the labial glands. NKKVI: STPPLY. From the buceal and supra-maxillary branches of the cervico-facial division of the facial nerve. ACTION. \Vhen the facial and labial portions act conjointly, they press together and project the lips. The labial fibers acting alone bring the lips and the angles of the mouth together and invert the lips. The facial fibers acting alone press the lips against the alveolar borders of the jaws, and, at the same time, evert the lips. The orbicularis oris is the antagonist of all those muscles which converge to the lips from the various parts of the face. Hypertrophy of the orbicularis oris or, rather, an increase of the connective tissue, particularly of tin- portion in the upper lip, to the extent of producing a considerable deformity, is sometimes seen, and indicates a plastic operation involving the removal of a trans- verse, wedge-shaped section from the lip. The levator labii superioris muscle (levator labii proprius) arises from the superior maxilla above the infra-orbital foramen, and is inserted into the upper lip, its fibers blending with the orbicularis oris muscle. At its origin it is over- lapped by the orbicularis palpebrarum, and covers the infra-orbital vessels and nerves. It is a landmark in exposing the infra-orbital nerve. NERVE SUPPLY. From the infra-orbital branch of the upper division of the facial nerve. ACTION. It raises the upper lip, at the same time making prominent the skin below the eye. DISSECTION. The levator labii superioris muscle is to be reflected downward from its origin, when will be exposed the levator anguli oris, the infra-orbital plexus of nerves, and the infra-orbital vessels. .-><><> SURGICAL .\\ATOMY. The levator anguli oris muscle (nmsculus caninus) arises from tin- canine I'M-- ii of the superior maxilla below the infra-orbital foramen, and is inserted into the angle of the mouth, supcrlirial to the hueeinator muscle, its (ihers Mending with the urhieularis oris, the y.ygomatici, and the dejiressor anguli oris muscle. NKIJVK SUPPLY. From the infra-orhital branch of the upper division of the faeial nerve. ACTION*. It raises and draws inward the angle of the mouth. The depressor labii inferioris muscle (quadratus menti) arises from the oblique line of the lower jaw by a wide origin, extending from a point below the foramen mentale nearly to the symphysis. Its fibers are assoeiated with those of the muscle of the opposite side, ascend, and are inserted into the integu- ment of the lower lip, blending with the orbicularis oris. Its outer border is overlapped by the depressor anguli oris muscle. NI:I;\ i: SUPPLY. From the supra-maxillary branch of the cervico-facial divi- sion of the facial nerve. ACTION. It depresses and everts the lip. The depressor anguli oris muscle, triangular in shape, hence also called triangularis oris, arises from the oblique line of the lower jaw external to the depressor labii inferioris muscles. Its fibers ascend, to be inserted into the angle of the month, intermingling with the zygomatici, the levator anguli oris, the risorius, and the orbicularis oris muscle. Its outer border overlaps the anterior part of the buccinator muscle. NERVE SUPPLY. From the supra-maxillary branch of the cervico-facial divi- sion of the facial nerve. ACTION. It draws the angle of the mouth downward and outward, producing an expression of sorrow. The levator labii inferioris, or levator menti, is a small muscle seen by everting the lip and dissecting off the mucous membrane on each side of the labial frenum. It arises from the fossa below the incisor teeth, near the symphysis. Its fibers descend, and are inserted into the integument of the chin. NERVE SUPPLY. From the supra-maxillary branch of the cervico-facial divi- sion of the facial nerve. ACTION.- It assists in raising the lower lip, at the same time wrinkling the integument of the chin over the point of its insertion. The zygomatic muscles pass obliquely from the /ygomatic arch to the upper lip and angle of the mouth. The zygomaticus major arises from the outer part of the malar bone in front of the suture, between it and the zygoma ; its fibers pass obliquely downward and inward, to be inserted into the angle of the mouth, blending with the fibers of the orbicularis and depressor anguli oris muscles. /'.I <'H. r.Ol The zygomaticus minor ari-es from tin- outer ]>;irt of tlic malar bone, anterior to the zygomaticus major, and behind the suture between the malar bone and tbe superior maxilla ; its fibers pass downward and inward, to be inserted into the lower border of the levator labii superioris muscle. It is often absent. NI:I:VK Sri'pLY. From the infra-orbital branch of the temporo-facial divi- sion of the facial nerve. ACTION. Tbe xygomaticus major draws the corner of the mouth upward and backward ; the /ygomatieus minor assists the levator labii superioris muscle in raising the upper lip. Bucco-pharyngeal fascia. Before making a dissection of the buccinator muscle, the thin layer of fascia which covers and adheres closely to its surface should be studied ; it is attached to the alveolar borders of the superior and infe- rior maxillary bones, and posteriorly, where it is thickest, is continuous with the fascia over the constrictors of the pharynx. It is called by Holden the " bucco- pharyngeal fascia," since it supports and strengthens the walls of the pharynx and mouth. The density of the buccal fascia offers a barrier to the escape of pus into the mouth or pharynx from an abscess in the cheek. The buccinator, quadrangular in form, is a thin, flat muscle which occupies the interval between the jaws at the side of the face. It arises from the outer surface of the alveolar borders opposite the middle and posterior molar teeth of the superior and inferior maxilla?, and behind from the pterygo-maxillary ligament. The pterygo-mn.i illnr;/ lii/nnK'nt is a fibrous band extending from the apex (hamular process) of the internal pterygoid plate of the pterygoid process to the posterior extremity of the internal oblique line (mylo-hyoid ridge) of the lower jaw ; it separates the buccinator muscle from the superior constrictor of the pharynx. The fibers of the buccinator pass forward, to be inserted into the orbicularis oris muscle at the angle of the mouth. The central fibers intersect one another, while the upper fibers pass to the upper lip and the lower fibers to the lower lip. In relation with the superficial surface of the buccinator muscle is a large mass of fat (buccal pad), which separates it from the ramus of the lower jaw, the masseter muscle, a small portion of the temporal muscle, and the muscles converging to the angle of the mouth. Absorption of the fat overlying the muscle is followed by sinking of the cheek, as seen in persons who are emaciated. In compression of the brain the flapping of the cheeks in breathing is the result of paralysis of the nerve supplying the buccinator, while the stertorous breathing (snoring) is the result of paralysis of the nerves of the soft palate. The duct of the parotid gland (Stenson's duct), which pierces the buccinator muscle opposite the second molar tooth of the superior maxilla, crosses the upper part of the muscle obliquely, at about a finger's breadth below the zygoma. It is also crossed by the facial artery and vein and 502 SURGICAL ANATOMY. by branches of the facial nerve. Internally il is lined l>y the mucous membrane n!' the month; between this and the muscle lie a number of racemo.~. Called the btlccal glands. A few of these glands are tonild on llie oilier surface of the muscle and are called molar glands. NEJIVK Sri'iM.v. I'Yom the facial nerve. The long luiccal nerve, a hraneli of the inferior maxillary, pierces the buccinator muscle on its way to supply the mucous niemhrane of the month. ACTION. The two huccinator muscles widen the aperture of the mouth transversely and contract and compress the cheeks so that during mastication the food will not remain hetwcen the cheeks and the teeth. When but one muscle acts, the angle of the mouth is drawn to that side, and the cheek is wrinkled ; when whistling, the muscle contracts and prevents bulging of the cheeks. It is hardly fair to the earnest dissector to leave this subject without the consoling reminder that the most expert dissectors can not bring out these muscle.- in the cadaver as they are shown in the anatomic plates. It must be remembered that some of the facial muscles belong to the panniculus carnosus group, so exten- sive in animals but so limited in man. In some faces the musculature is a com- plex network of subcutaneous fibers running in all directions. In a muscular subject a large number of distinct fasciculi are seen crossing one another, and more or less merged with the constant muscles of the face. This difference in the amount of facial musculature undoubtedly accounts for much of the variation in the amount of facial wrinkling observed in different persons. It is safe to say that a dissection of the muscles of the face with their boundaries as well defined as shown in pictures does more credit to the dissector's skill in imitating a diagram than to any painstaking effort to exhibit the natural state of the parts. The Facial Artery, a branch of the external carotid, enters the face over the body of the lower jaw, at the anterior inferior angle of the masseter muscle, where its pulsation may readily be felt and it may be compressed against the bone. Thence it ascends forward across the cheek, over the buccinator muscle, and beneath the platysma myoides muscle, to the angle of the mouth ; thence to the side of the nose, to terminate at the inner canthus of the eye as the angular artery. Where the artery passes over the lower jaw it is covered by the platysma myoides muscle and the deep fascia ; near the mouth it passes beneath the zygomatici major and minor and the risorius muscle ; and along the side of the nose it is usually covered by the levator labii superioris alseque nasi. It rests successively on the lower jaw, the buccinator, and the levator anguli oris muscle. The companion vessel of the facial artery, the facial vein, runs in an almost straight line from the inner canthus of the eye to the anterior inferior angle of the masseter muscle, being in contact PLATE CXXXII. Supraorbital a Frontal a. Orbital a. Anterior temporal a. Posterior temporal a. Occipital a. Posterior auricular a. Facial a Inferior Labial a. Inferior coronary a. Superior coronary a. Superficial temporal a. Anterior auricular a. Middle temporal a. Parotid gland Transverse facial a. Stenson's duct ARTERIES OF SCALP AND FACE. 504 PLATE CXXXIII. Malar br. of facial n. Ttansverse facial a. Or(v- I Temporal br. of facia! n. Temporal br. of o : Supraorbital Supraorbttal a. Supratrochlear n. Posterior temporal a. '-temporal n. Occipital a. Small occipital n. Posterior auricular a. Infratrochlear n, Artery of septum Lateral nasal a. Superior coronary a Inferior coronary a Inferior labial a Facial a Facial v. Anterior auricular a. Middle temporal a. Parotid gland Supramaxillary br. of facial n. Stenson's duct Buccal br.of facial n. Infraorbital br.of facial n, Socia parotidis ARTERIES, NERVES, AND MUSCLES OF SCALP AND FACE, 505 FACE. on? with tlio facial artery at thrse points, luit dsc-where above and external to it. The artcrv is crossed by filaments of the facial nerve, while the levator lahii superioris niu.-cle separates it from the infra-orhital nerve liehind. Branches of the Facial Portion of the Facial Artery. These are the mus- cular, inferior labial, inferior coronary, superior coronary, lateralis nasi, and angular. The muscular branches are directed outward to supply the buccinator, niassetcr, and internal pterygoid muscles. They anastomose with the masseteric and buccal brandies of the internal maxillary and with the infra-orbital and transverse facial arteries. The inferior labial artery passes inward beneath the depressor anguli oris to supply the muscles and integument of the lower lip and chin. It anastomoses with the inferior coronary, the submental branch of the facial, and the mental branch of the inferior dental artery. The inferior coronary artery arises, either independently or in common with the inferior labial, from the facial artery near the angle of the mouth. It passes forward and inward in a tortuous manner beneath the depressor anguli oris toward the angle of the mouth, then pierces the orbicularis oris, and continues between it and the mucous membrane along the free margin of the lower lip. It anas- tomoses with the inferior coronarj 7 artery of the opposite side, the inferior labial, and the mental branch of the inferior dental artery. The superior coronary artery, which is larger and takes a more tortuous course than the inferior coronary, arises from the facial artery beneath the zygo- maticus major muscle. It pierces the orbicularis oris, and runs between it and the mucous membrane along the free margin of the upper lip to anastomose with the artery of the opposite side. By the anastomosis of the superior and inferior coronary arteries with their fellows an arterial circle is formed, which surrounds the mouth and can be felt pulsating on the internal surface of the lips between one-fourth and one-half of an inch from the junction of the skin and the mucous membrane. A small branch to the ala nasi and numerous branches to the labial glands are given off from this circle. The artery of the septum of the nose is a branch of the superior coronary. The twigs of this arteria septum narium are a common source of epistaxis (nose- hired). The hemorrhage from the branches of this vessel is readily controlled by compression of the artery of the septum, either by direct backward pressure against the upper lip, or by pressure from within outward, as when a firm pledget of cotton, paper, or other substance is pushed well up under the lip so as to put its tissues upon the stretch and occlude the lumen of the artery. This is a common procedure practised by the laity. Another simple method is that of holding the cartilaginous end of the nose between the thumb and finger. . SURGICAL .I.Y.r/'o.l/r. Harelip. In the operation tin- harelip the bleeding can he controlled hy grasping the lip between the ihunih and lot-Hinder. In introducing the harelip pin or suture, it must be passed deep enough lo go hcneatli the divided coronary artery. Harelip is a congenital detonnity consisting of one or more lissttres in the upper li]>, the result of arrested development. It may he single or donhle, the fissure or lissures being to the side of the median line of the lip, corresponding to the line of union between the intermaxillary and the superior maxillarv hone. In double harelip the intermaxillary hone is often displaced forward. Double harelip is frequently associated with cleft palate. The lateralis nasi artery arises from the facial artery opposite the wing of the nose, and passes forward over the lower part of the nose and over the ala ; it supplies the side and dorsum of the nose, and anastomoses with the lateralis nasi artery of the opposite side, the nasal branch of the ophthalmic, the infra-orbital, and the artery of the septum. The angular artery, the terminal part of the facial, passes to the inner canthus of the eye, where it lies on the nasal side of the lacrymal sac and tendo oculi ; it anastomoses with the nasal branch of the ophthalmic, and with the infra- orbital artery, and supplies branches to the cheek. In opening an abscess of the lacrymal sac it is important to bear in mind the situation of this artery on the inner side of the sac. Nervi molles. The facial artery and its branches are surrounded by a minute plexus of sympathetic fibers (nervi molles) not demonstrable maeroscopi- cally. These fibers are brandies of the superior cervical ganglion of the sympa- thetic, and supply the walls of the artery and its branches; they furnish the sympathetic root to the submaxillary ganglion. Transverse facial artery. Passing transversely across the face between the zygoma and the duct of the parotid gland, and resting upon the niasseter muscle, is the transverse facial artery, which arises from the temporal artery in the substance of the parotid gland. It supplies the small, often detached, part of the parotid gland (the socia parotidis) in relation with the duct, the massctcr and orbicularis palpebrarum muscles, and the integument. It anastomoses with the infra-orbital, facial, and masseteric arteries. It is accompanied by two or three branches of the facial nerve. It is quite small except when it supplies those parts which usually receive blood from the facial artery. It occasionally gives off the coronary and nasal arteries, the facial itself being small. It arises, at times, from the external carotid artery. The facial vein, the continuation of the angular vein, and formed by the union of the frontal and supra-orbital veins, commences at the inner canthus of the eye and, PLATE CXXXIV. Transverse faci Front Supraorbit th mastoid v. VEINS OF SCALP FACE, AND NECK, 509 FACE. 511 :is already stated, runs in an almost straight line to the anterior inferior angl the massetcr muscle, where it comes into relation with the outer siile of the facial artery. In its course across the face it lies above ami to the outer side of the artery, passing over the leva tor lahii superioris, beneath the zygornatic muscles, and over the parotid duet, the buccinator muscle, the anterior inferior angle of the masseter muscle and masseterie fascia, and the body of the lower jaw. Below the jaw it is joined liy the anterior branch of the tcmporo-maxillary vein, and empties into the internal jugular vein. It receives veins from the lower eyelid (the inferior palpebral), from the side of the nose (the lateral nasal), from the orbital vein, and, heiieath the zygomaticus major muscle, a branch (deep facial) from the ptervgoid plexus, besides muscular branches and branches corresponding to those of the facial artery. The facial vein through the angular, in which it commences communicates freely with the ophthalmic vein, and thus with the cavernous sinus ; and it also communicates with the cavernous sinus, through the deep facial vein with the pterygoid plexus of veins, which, in turn, communicates with the sinus by means of small veins which pass through the foramen ovale, the foramen of Vesalius, ami the middle lacerated foramen. Owing to the free communication between the vein and the cavernous sinus, the latter is endangered by any inflam- matory condition of the facial vein. Disease involving the facial vein. The facial vein, us a rule, has no valves ; it will therefore be understood how emholi are readily carried to the internal jugular vein and thus into the general circulation. Carbuncle of the face may prove fatal by inducing thrombosis of the cerebral sinuses through the com- munications previously described. Any deep inflammation of tin 1 face, as phleg- monous erysipelas, may he complicated by thrombosis or pyemia. The injec- tion of facial nevi in infants may result in death from thrombosis, owing to the direct communication of the facial with the internal jugular vein. Pulmonary embolism and death have followed the injection of perchloric! of iron for nevoid growths of the face. In arterio-venous aneurysm of the cavernous sinus arterial blood, through the ophthalmic and angular veins, flows through the facial vein and gives rise to a pulsating varicose condition of the latter vein and a distinct thrill and bruit. Vascularity of the face. It has been demonstrated that the tissues of the face are very vascular. In persons exposed to cold, or in those addicted to strong drink, the very small vessels of the skin, especially over the nose, appear per- manently injected or varicose. Attention has been called to the fact that nevi and various forms of erectile tumors arc common about the face. AVounds of the face, while they bleed freely, heal very rapidly; their edges should be carefully adjusted as soon after the accident as possible. " Extensive flaps of :.]_' SURGICAL ANATOMY. skin which have been torn up in lacerated wounds of the face often retain their vitality in almost as marked a manner as similar flaps torn from the scalp" (Treves). The anastomose- of the facial artery are so free that when the vessel is divided, both ends bleed freely and. according to the general rule, they should both be tied. I)ISSI-:i-t/,-ii/n, or interpalpebral slit. At the points of union of the eyelids are the e.rfrrituf irml iittfrim/ c!<> SURGICAL ANATOMY. inferior nieatus of the nose. In tin- loose subconjunctival tissue- there are not infre- (|Ueiitly seen, (specially in elderly person-, small yellowish masses of fal, called pingueculse. In jjosi-ciinjuiictival operations, as in section of the oqular muscles, the con- junetiva must lie cut. Its lax attachment to the sclera is now of advantage. for a loose fld is readily raised with the forceps and incised to the rcnperi<>r maxilla and the crest of the lacrymal bone to the internal extremities of the Iarsal cartilages. The division of the tendo oculi which is attached to the nasal proce-- of the superior maxilla passes in front of the lacrymal sac, while the limb attached to the crest of the lacrymal bone passes over its outer wall. The orbito-tarsal ligaments (palpebral fascia?) are fibrous membranes continu- ous with the periosteum, and extend from the superior and inferior orbital mar- gins to the tarsal cartilages. In the upper lid the orbito-tarsal ligament fuses with the tendon of the levator palpebnc superioris muscle. These ligaments prevent pus in the subcutaneous areolar tissue from making its way into the orbit, and hence are called the septa orbitale. The tarsal cartilages, situated in the free margins of the eyelids, are two plates of dense connective tissue. They are thickest at their free, or ciliary, margins, and give support and shape to the eyelids. The cartilage of the upper lid is much larger than that of the lower, and gives attachment to the aponeurosis of the levator palpebrse superioris muscle. In both lids the attached margins of the tarsal cartilages are continuous with the orbito-tarsal ligaments. The Meibomian glands are sebaceous glands lodged in the substance of the tarsal cartilages, and number between twenty and thirty in the upper and some- what less in the lower lid. The orifices of the glands open on the free borders of PLATE CXXXVI. Superior portion of lacryma! gland Inferior portion of lacryinal gland Levator palpebrae superioris m Frontal sinus Meibomian glands Conjunctiva Orifices of ducts of meibomian glands Orifices of lacrymal ducts Tensor tarsi m. Lacrymal sac Lacrymal canaliculi LACRYMAL APPARATUS AND MEIBOMIAN GLANDS. 517 r.i a-:. 519 the lids behind (lie lashes. Each salami consists of a straight tube with many short, Lilind, diverticula. The Meibomian glands secrete a sebaceous material which prevents the lids from adhering, and are readily distinguished as closely adjacent, vertical, parallel, yellow streaks across the inner surface- of the lids. When the duet of one of these glands becomes occluded, a retention cyst, similar to a wen, is formed. Non-striated muscular iihers are found in hoth lids. In the upper lid these fillers originate from the lower surface of the levator palpebrffi superioris ; in the lower lid they arise from the vicinity of the inferior oblique muscle. In hoth lids they are inserted close to the attached border of the tarsal cartilage. They arc known as the superior and inferior palpebral muscles of Midler. Hi, OOD SUPPLY. The eyelids receive their blood supply from the palpebral and lacrymal branches of the ophthalmic artery and from small branches of the temporal and transverse facial arteries. The palpebral branches of the ophthalmic, two in number, arise from that artery near the pulley of the superior oblique muscle; one is found in each lid and runs through the fibrous tissue layer of the lids between the orbicularis palpebrarum muscle and the tarsal cartilages near their margins. The lacrymal is the first branch of the ophthalmic artery. It accompanies the lacrymal nerve and gives oil' palpebral twigs which anastomose with the other palpebral arteries to form the tarsal arches. The ri'hix i >f (lie ei/e!i/ls are larger than the arteries, and outnumber them. They empty into the frontal and angular veins at the inner canthus, and into the orbital vein at the outer canthus. Some of the veins of the lids pass between and through the bundles of fibers of the orbicularis palpebrarum, and hence in many inflammatory conditions of the conjunctiva and cornea in children, in which prolonged spasm of this muscle occurs, the lids are very apt to become edematous, from interference with the venous How (Fucho). NKUVK SUPPLY. The nerve supply is free. The nerves to the palpebral portion of the orbicularis palpebrarum muscle arise from the -facial nerve and enter the lids near the outer canthus. The cutaneous filaments of the upper lid are obtained from the lacrymal, supra-orbital, and eupra-trochlear nerve, and the lower lid derives its supply from the infra-orbital and infra-trochlear nerves. The non-striated muscular tissue of the lids is supplied by the sympathetic nerve. The lymphatics of the eyelids pass to the parotid and submaxillary lymph glands. The conjunctiva has been described. The levator palpebrae superioris muscle arises from the under surface of the lesser wing of the sphenoid bone above the optic foramen ; its fibers terminate VJi> SURGICAL .\\.\TOMY. in ;i broad, tliiu aponeunMs which is inserted into the upper border of the superior tarsal cartilage. '1'his muscle runs aliove the superior red us. and its uj>]ier suri'aee is in relation witli the frontal nerve and tin 1 supra-orbital artery. The parotid gland, the largest of the saliva ry glands, weighs from one-half to one ounce. It is situated on the side of the face, and extends as high as the xygoma and below the level of the angle of the lower jaw. It covers about one- third of the masseter muscle, and extends backward to the external auditory ineatns, the masloid process, and the sterno-niastoid muscle. It is lodged in tin- space between the ranius of the lower jaw and the niastoid process. This spact known also as the bed of the parotid gland can be increased in si/e by extending, and diminished by Hexing, the head. With the mouth wide open in which posi- tion the angle of the jaw is carried backward and the condyle forward the width of the space is diminished below, but increased above. The si/e of the space ig influenced by the age of the individual. In the infant, owing to the obliquity of the ranius and the absence of the angle of the lower jaw, it is broader, in propor- tion, below. Ill advanced age, when the teeth have fallen out. thus allowing the angle of the lower jaw to project forward, the space is broader below. When operating in this space these facts should be kept in mind, as it may be necessary to take advantage of them. The gland has three large processes or lobes : one. the ijli-nniil lulu-, extends upward into the posterior part of the glenoid cavity of the temporal bone which it occupies; another, the ji/fri/f/oiil /<,/,<; extends forward beneath the minus of the lower jaw, between the external and internal pterygoid muscles; the third process, the cartiy swelling in the parotid region, lietro-pharyngeal growths as, for example, sarcomata, when they have attained any si/.e -cause bulging of the parotid region : and, conversely, tumors of the parotid may bulge into the pharynx. The severe pain in a rapidly growing tumor or abscess of the gland is due to the density of the fascia covering it. This, too, makes it difficult to detect fluctuation early. It also explains why the pus in a parotid abscess is so slow to find its way to the surface, and why an early opening should be made. The intimate relation existing between the parotid gland, the external auditory nieatus, and the temporo-maxillary articulation is to be borne in mind, as a parotid abscess may open into the meatus or cause involvement of the joint, Purulent meningitis and thrombosis of the cranial sinuses may be caused when pus finds its way through the foramina at the base of the skull. The sensory nerves supplying the parotid gland are the auriculo-temporal branch of the inferior maxillary nerve, the great auricular branch of the cervical plexus, the facial nerve, and branches from the carotid plexus of the sympathetic nerve. In painful affections of the gland the pain is apt to be referred to the areas of distribution of these nerves. The parotid lymphatic glands. Lying upon the surface of the parotid gland (in front of the cartilage of the ear, and close to the root of the zygoma) are one or more superficial lymphatic glands, enlargement of which must not be mistaken for a similar condition of the parotid gland itself. Contents of the parotid gland. The parotid gland is important, not only on account of its function, of the position which it occupies, and of the relation it bears to the surrounding parts, but also because important structures are found in it. These structures are, from without inward : The facial nerve, passing from behind forward ; the temporo-maxillary, superficial temporal, internal maxillary, and posterior auricular veins; the commencement of the external jugular vein ; the external carotid artery which supplies branches to the gland and divides at the neck of the lower jaw into its two terminal branches the temporal and internal '>!! SURGICAL ANATOMY. maxillary arteries; the terminal part of the great auricular nerve: and one or two lymphatic glands. The posterior auricular hranch of the external carotid artery and the transverse facial hranch of the temporal artery arise in the substance of I he inland. The parotid gland is separated from the internal carotid artery, from the internal jugular vein, and from the pneumogastric. glosso-pharyngval, and hypo- glossal nerves hy a thin layer of fascia; therefore in stab wounds of the parotid region involving one of the two carotid arteries it may be difficult, at first, to tell which of the two vessels has been wounded. From an anatomic point of view it is difficult to sec how complete removal of the parotid gland is possible, yet the operation has been done so many times by skilful surgeons that there is no question of its feasibility. Doubtless, as long ago suggested by Fiihrer, when the gland becomes the site of a neoplasm it becomes more compact, its processes being rounded off, as it were, and lifted away from the surrounding structure-;. Complete removal of the parotid gland results in paralysis of the muscles of expression, for it is impossible to avoid dividing the facial nerve. The author has seen a growth of the overlying lymphatic gland cause facial paralysis from pressure, and thus so closely simulate a parotid neoplasm as to be pronounced a tumor of the parotid gland ; but upon the removal of the growth the parotid gland was seen to occupy the bottom of the wound, and to be in a very much atrophied condition. Socia parotidis. That portion of the parotid gland resting upon the masseter muscle above the parotid duct (Stenson's duct), and quite separate from the gland proper, is known as the socia parotidis. Its duct empties into Stenson's duet. Stenson's duct. Running about one finger's breadth below the zygoma, or in a line drawn from the lower margin of the concha to a point midway between the free margin of the upper lip and the ala of the nose, is the duct of the parotid (Stenson's duet). It is about two inches in length by one-eighth of an inch in diameter, being narrowest at its point of communication with the mouth. It lies between the transverse facial artery above and the buccal branch of the facial nerve below. The duct runs over the masseter muscle, turning abruptly inward at its anterior border, passes through the mass of fat overlying the buccinator muscle and beneath the facial vein, and pierces the buccinator muscle to open into the mouth opposite the crown of the second molar tooth of the upper jaw. The turn of the duct around the anterior border of the masseter muscle must be borne in mind when passing a probe into the duct from the mouth. In opening a parotid abscess the incision should be horizontal, and should be made below the line of the duct and in front of the posterior border of the ramus of the lower jaw. Failure to observe this caution may result in section of the duct, with r.ics. resulting fistula ('salivary fistula). It is also advisable to take every precaution against cutting through the gland tissue in opening a jiarotid aliseess, for these collections of pus, like those of the mamma-, generally atl'ect the connective tissue of the gland and not its snhstaiice or parenchyma. Stenson's duct mav he divided into a niassrteric and a bnccal portion. The i,ttixx/ft //( /mi -tin a rests upon the ma>seter musele and the /nnrn/ /mrt exh-nd> from the anterior horder of the masseter muscle to the termination of the duct in the mucous memhrane of the check. Fistula. 1 of the masseteric part are closed with difficulty, whereas fistula' of the hnccal portion are remedied hy making an opening from the duct into the mouth on the proximal side of the fistula. The author has successfully treated listula 1 of the buccal portion hy exposing the duct through an incision in the cheek, dividing the duct at the proximal side of the fistula, freeing the duct from the surrounding tissues, and stitching the divided end to the margins of an opening made in the mucous membrane of the mouth. DISSECTION. Before turning over the head to make the dissection of the oppo- site side of the face, the parotid gland should he removed entire; this operation will convey an approximate idea of the difficulties which would attend the removal of the gland in the living subject. The masseter muscle should then be exposed and (lie external ear dissected. In exposing the parotid gland, its fascial covering is seen to be continuous anteriorly with the fascia covering the masseter muscle, and, therefore, the parotid and masseteric fascia: are practically one. These fascia- are derived from the superficial layer of the deep cervical fascia, which is continued upward over the body of the lower jaw and attached above to the zygoma. By displacing the parotid gland forward and removing the fascia covering that portion of the masseter muscle in advance of the gland, the muscle itself is exposed. The masseter, the most superficial of the muscles of mastication, is of quad- rate form, and arises as two portions a large, tendinous, superficial layer, and a small, Ik-shy, deep layer. The superficial sheet arises from the anterior two-thirds of the lower border of the zygomatie arch and from the lower border of the malar hone ; its fibers pass downward and backward to he inserted into the outer surface of the angle and lower portion of the ramus of the lower jaw. The deep sheet arises from the posterior third of the lower horder and all of the inner surface of the zygoma ; it passes downward and forward to be inserted into the upper half of the ramus and the outer surface- of the coronoid process of the lower jaw. The posterior portion of the muscle is concealed by the parotid gland. In relation with the superficial surface of the muscle are the orbicularis palpebrarum, the zygomatici major and minor, and the platysma myoides muscle, the anterior margin of the parotid gland, Stenson's duct, the transverse facial vessels, branches of the facial nerve, and, at its anterior inferior angle, the facial vein. In relation V_M SURGICAL AXATO-UY. witli its dec]) surface are llic buccal pad of fat. the l)iiccin;(t(ir iind a small part of the temporal muscle, the masseteric arterv and nerve, and the minus of the jaw. l)L(Kii) SriTi.v. From the masseteric brunch <>f the internal maxillary, the transverse facial, and the facial artery. NKKVK Sri'i'i.v. From the masseteric nerve, a brunch of the interior maxil- lary division of the trifacial nerve. ACTION. It raises the lower jaw, us in mastication. The External Ear consiMs of the pinna, or auricle, and of the tube leading to the tympanic membrane the external auditory cunul. The pinna collects the vibrations of sound, and the canal conveys them to the tympanum. The pinna, or auricle, is pyriform in shape, with its concave surface diivcicd outward and slightly forward, and consiMs of a layer of yellow fibre-cartilage having an uneven surface covered with integument. It is attached to the com- mencement of the external auditory meatus, and consists of various elevations and depressions, each elevation having a corresponding depression on its opposite surface. The deep hollow in its center, which is wide above and narrow below, is called the concJm. The concha leads to the commencement of the external audi- tory meatus. and is partly divided into two by the beginning of the helix. The liclix passes upward, forms the rim of the pinna, and terminates behind in the Io/ml<; which is the lowest portion of the auricle and consists of fatty and areolar tissue. Internal to the helix is the depression called the fossa of tin- lihoid fossa. Internal to the fossa of the helix is the ridge bounding the concha behind and above. This ridge is called the (inllirfl.,- : it begins above the lobule, at a small prominence, the cintltrf tin- iniflidi.c. In front of the concha and projecting backward over the orifice of the external audi- tory meatus is the tragus. Between the trugus and antitragus is a notch the incisuni intertragica. DISSECTION. The integument should be removed from the pinna, when the small and rudimentary muscles and the cartilage will be exposed. The integument of the pinna is thin and delicate. It contains sebaceous glands which are largest in the concha, and here the ducts of the glands often become filled with foreign matter, giving rise to the so-called comedones. Upon the posterior aspect of the auricle the integument is less firmly attached to the underlying parts than elsewhere, consequently inflammatory swellings, as in erysipelas, are most marked in this situation. Extravasations of blood beneath the skin are not uncommonly seen as the result of blows upon the ear ; these so-called othematomuta have been most often observed in insane persons and in prize-fighters. According to Yirchow and PLATE CXXXVII. Heli Fossa of helix Darwin's tubercle Antihelix Concha Antitragus Lobule Fossa of antihelix Tragus isura intertragica PINNA 525 PLATE CXXXVIII, Helix Darwin's tubercle ; major m. Obliquus auris m. Tragicus m. Fibrous band Helicis minor m . Antitragicus m. Processus caudatus Transvesus auris m. Fissure of Santorini INTRINSIC MUSCLES OF PINNA. 527 FACE. r,-_><) Ludwig Meyer, degenerative changes in the blood-vessels and cartilage favor the occurrence of such extravasations. Cicatricial contractions may cause deformity of the pinna alter the absorption or evacuation of such hematuinata. I'nder the integument of tlie lobule polity deposit- (tophi) arc sometimes found. The Muscles which move the cartilage of the ear as a whole, three 1 in number, have heel) described under the dissection of the scalp. The muscles proper <>f the auricle, which extend from one part of the cartilage to another, are six in number namely, the muscle of the trains, the muscle of the antitragus, the small muscle of the helix, the large muscle of the helix, the transverse muscle of the auricle, and the oblique muscle of the auricle. The tragicus, the muscle of the trains, is situated upon the outer surface of the trains. The antitragicus, the muscle of the antitragus. arises from the outer part of the antitragus : its libers pass upward and are inserted into the posterior extremity of the helix. The helicis minor, the small muscle of the helix, is attached to the commence- ment of the helix and extends into the concha. This muscle is sometimes absent. The helicis major, the large muscle of the helix, is situated upon the anterior margin of the helix : it arises above the small muscle and is inserted into the front of the helix, where it begins to curve backward. The transversus auris, the transverse muscle of the auricle, is situated on the back of the auricle in the depression between the helix and the convexity of the concha ; it arises from the convexity of the concha and is inserted into the back of the helix. The obliquus auris, the oblique muscle of the auricle, extends from the upper back part of the concha to the convexity immediately above it. NERVE SUPPLY. The pinna derives its nerve supply from the auriculo- temporal, the posterior auricular, the auricular branch of the pneumogastric (Arnold's nerve), the occipitalis minor, and the auricularis magnus nerve. ACTION. The muscles of the helix assist those of the tragus and antitragus in retarding the passage of sound to the meatus. BLOOD SUPPLY. The pinna is well supplied with freely anastomosing vessels branches of the posterior auricular, temporal, and occipital arteries. The veins accompany the corresponding arteries. The numerous lymphatics empty into the pre-auricular glands and into those situated upon the insertion of the sterno-mastoid muscle. The cartilage of the pinna is a single piece, and presents the irregularities characteristic of the external ear. It is prolonged inward in the shape of a tube 34 SURGICAL ANATOMY. wliicli forms the outer part of the external auditory nicatus ; it is wanting IH tween the trains and the commencement of the helix, the interval between them being occupied by lihrous tissue. Where the helix makes its lirst liend, at the front part of the pinna, is a conic projection of the cartilage the process of the helix. At the highest part of the helix there is not infrequently to he seen another conic projection, to which Darwin tirst called attention; he regards it as the represen- tative of the extreme tip of the pinna of some of the lower animals. At certain places the cartilage is incomplete; these gaps are known as fissures, and are located as follows : at the anterior part of the pinna, behind the process of the helix (fissure of the helix) ; on the surface of the tragtis ; and at the lower part of the anthelix. In the piece of cartilage which forms the outer part of the meatus are two fissures the //'.-.-X///VN i if Suii/nriiii. The pinna is attached anteriorly to the root of the x.ygoma and posteriorly to the mastoid process by hands of fibrous tissue ; iii addition, there are various intrinsic ligaments, uniting the different parts. DISSECTION. Turn the head to the opposite side, fix it with hooks, and work out the facial nerve and the branches of the trifacial nerve which make their exit upon the face. Expose the facial nerve by a longitudinal incision carried into the substance of the parotid gland in front of the lobe of the ear, cutting away a little of the gland with each movement of the knife until the nerve is seen, when it can be traced both backward and forward. The facial nerve (the seventh cranial) is the motor nerve of the face; it consists of three portions the intra-cranial, the temporal, and the facial. The facial portion, that which concerns us in this dissection, supplies all the muscles of expression and the platysma, the buccinator, the occipito-frontalis, the attrahens, attolens, and retrahens aurem, the posterior belly of the digastric, and the stylo- hyoid. A line drawn from the anterior border of the mastoid process opposite the li.-iM' of the lobule of the ear downward and forward across the face for about one inch will represent the course of the facial portion of the trunk of the nerve. COURSE. It leaves the cranial cavity through the internal auditory meatus in company with the auditory nerve, the pars intermedia of Wrisberg, and the auditory artery. Reaching the bottom of the internal auditory meatus it enters the facial canal, or aqueductus Fallopii of the temporal bone, from which it makes its exit by way of the stylo-mastoid foramen. Passing downward and forward from the foramen it enters the parotid gland, crosses the external carotid artery, gives off a posterior auricular, a digastric, and a stylo-hvoid branch, and terminates in two divisions the temporo-faeial and the cervico-facial. The posterior auricular nerve, the first extra-cranial branch, passes upward in the groove between the ear and the mastoid process, communicates with the PLATE CXXXIX. Temporal br. of orbital n Supraorbi: Supratrochlear Malar br. of facial n. Temporal br. of facial n. Great occipital n. Small occipital n. 'Auriculo-temporal n. Infraorbital br. of facial n. Great auricular n. Supramaxillary br. of facial n. Buccal br. of facial n. Infraorbital br. of superior maxillary n. Mental n. Infratrochlear n. Nasal n" NERVES OF SCALP AND FACIAL NERVE. 531 l-'A i-ii-i/ In-nni-li emerges from the lower horder of the ]>arotiil gland in front of the external jugular vein and passes downward and forward toward the sternum heneath the platysma myoides muscle, which it supplies. It communicates with the great auricular and superficial cervical nerves hrauehes of the cervical plexus. The infra-maxillary hranch can he traced when dissecting the superficial fascia of the neck. The pes anserinus (plexus parotidetis). The hreaking up of the two terminal divisions of the facial nerve within the substance of the parotid gland gives rise to a plexus, the pes anserinus (goose's foot). Bell's palsy. 1'aralysis of the facial nerve is known as Bell's palsy, and may be either central or peripheral. A central paralysis is due to involvement of the nucleus of the nerve, its center in the cortex of the brain, or the fibers connecting these, and results from pressure, as by hemorrhage, abscess, or tumor; it may also be brought about by degenerative processes in the brain. A peripheral paralvsis is due to affection of the trunk of the nerve within the cranial cavil v by tumors or meningitis; within the facial or Fallopian canal, by middle ear disease or frac- ture of the base of the skull ; external to the stylo-mastoid foramen, by a growth at the stylo-mastoid foramen, rapidly growing tumors or abscess of the parotid gland, division during an operation, or exposure of the face to cold. When the lesion is situated beyond the origin of the chorda tympani nerve the muscles of expression and the buccinator muscle on the same side of the face become paralysed, the mouth is drawn to the opposite side, and the affected side of the face becomes flattened and free from wrinkles. Through paralysis of the orbicularis palpebrarum muscle the eye on the paralyzed side remains open, and the tears run down the cheek. The anterior naris of the affected side is smaller in appearance through paralysis of the nasal muscles. 1'aralysi.s of the buccinator muscle causes the food to collect between the cheek and the teeth of the affected side. Through paralysis of the orbicularis oris muscle the saliva dribbles from the mouth, and the patient can not whistle. When the lesion is situated in the aqueductus Fallopii PLATE CXL t of emergenc ; of spinal accessor OPERATION FOR EXPOSURE OF FACIAL NERVE. 536 PLATE CXLI. Supraorbital a Supraorbital n. Frontal a. Infraorbital br.of facial n. oral br. of orbital n. Malar br.of facial n. Temporal br.of facial n. Temporal fascia Infratrochlea n. Nasal n Auriculo-temporal n. Middle temporal a. .Anterior auricular a. Superficial temporal v Superficial temporal a. 'Facial n. Posterior auricular a. Internal maxillary a. Buccal br.of facial .n. Inframaxlllary br.of facial n. Mental n! Mental a. Labial brt Facial v. Facial a. nfraorbital n. Palpebral br. Infraorbital a. Nasal br. Supramaxillary br.of facial n. Transverse facial a. TEMPORAL FASCIA AND NERVES OF FACE. 537 ,-,:;:) and above the origin of Hie chorda tympani nerve, there is loss of the sense of taste in (he anterior two-thirds of the tongue on the diseased side, and through paralvsis of (lie stapedius muscle loud sounds are distressing. \\'hen tlie lesion is eentral or in the hrain, the hrow and eyelid are not alfected /'. e., the f'rontalis, corriigator supercilii, and orhieuhiris ]>a Ipehraniin muscles are not involved. This is probably due to escape of the fibers which arise from the nucleus of the opposite side. SJHIXIHX, both tonic and dome, of the muscles supplied by the facial nerve may occur. 1'ersi^tent spasm oi these muscles is relieved by stretching the facial nerve. Operative exposure of the facial nerve. The facial nerve is exposed by carrving a vertical incision from in front of the mastoid process and behind the lobule of the ear downward toward the angle of the lower jaw, laying bare first the posterior border of the parotid gland, which is displaced forward, and then the anterior border of the sterno-mastoid muscle at its insertion. The parotid gland should be separated from the mastoid process to the depth of about one centimeter, when the nerve may be seen. The exact location of the nerve in tin- wound can be ascertained by the use of the faradic battery. The trifacial nerve. The branches of the trifacial or fifth nerve which make their exit upon the face are the supra-orbital and the supra-trochlcar (pre- viously described), the lacrymal, the infra-orbital, the malar, the anterior branch of the nasal, and the mental nerve. The lacrymal nerve, the smallest of the ophthalmic branches, supplies the lacrymal gland, and frequently communicates with the temporal branch of the temporo-malar nerve in the orbit ; it sends a small filament the palpebral to the skin and conjunctiva around the outer canthus of the eye. The infra-orbital nerve, the terminal branch of the superior maxillary division of the trifacial nerve, emerges from the infra-orbital foramen in company with the infra-orbital artery, under cover of the levator labii superioris muscle. It immediately divides into palpebral, nasal, and labial branches. The palpebral fn-i/ncJtcs, the smallest, pass upward beneath the orbicularis palpebrarum muscle, supply the lower eyelid, and communicate with the facial and the malar branch of the orbital or temporo-malar nerve. The nasal branches, three or four in number, pass inward under the levator labii superioris alseque nasi muscle to supply the side of the nose, and communicate with the external (naso-labial) branch of the nasal nerve. The labial briuichcx, usually four, are larger than the palpebral or nasal branches, arid descend beneath the levator labii superioris muscle to supply the upper lip. Beneath the levator labii suporioris the branches assist in forming the infra-orbital plexus. (See description of plexus under Facial Nerve.) 340 SfRGICAL ANATOMY. Tin; infra-orbital artery, a branch uf ihe internal maxillary, accompanies the infra-orbital nerve through tin- infra-orbital foramen, and divides into l>ranclics which are distributed like tho.se of the nerve. It anaMomoses with the 1ransvei>e facial, facial, and ophthalmic arteries. The infra-orbital vein communicates with the facial vein in front, and empties into the ptcrygoid plexus of veins. Th<> malar division of the orbital or temporo-malar branch of the >uperior maxillary nerve makes its exit through a foramen in the malar bone, pierces the orbicularis palpebrarum muscle, and supplies the skin of the cheek covering the malar hone. It communicates with the facial and the palpebral branches il SURGICAL ANATOMY. It is related, externally, with the ramus of the inferior maxilla, the temporal and masseter muscles, tin- superficial portion of the internal pterygoid mu>cle, the internal maxillary artery, the anterior and posterior deep temporal arteries, and the huccal artery and nerve. Internally, it is in relation with the deep part of the internal pterygoid ninsele, the middle meningeal artery, and the interior maxillary nerve, the internal lateral ligament of the lower jaw, the lingual and inferior dental nerves, which emerge from beneath its lower horder : the long Iniceal nerve, which runs between its two heads; the chorda tympani nerve, and the anterior and posterior deep temporal and masseteric nerves, which pass out from beneath the upper border of the muscle. Bi.oon Si iM'i.Y. From the external pterygoid branches of the internal maxil- lary artery. NicuvK SCPPLY. From the inferior maxillary nerve. ACTION. The external pterygoid muscles acting together pull the lower jaw forward ; alternately, they move it forward and laterally ; and, singly, forward and to the opposite side. They are muscles of trituration. The internal pterygoid muscle (the internal masseter) arises by two heads, a superficial and a deep. The superficial, the smaller, arises from the lower and back part of the tubcrosity of the upper jaw, and the outer side of the tuberosity of the palate bone. The deep lies behind the lower head of the external pterygoid and arises from the internal surface of the external pterygoid plate, and from the grooved portion of the tuberosity of the palate bone situated in the pterygoid fossa. These two heads unite at the lower margin of the external pterygoid muscle, and thence extend downward, backward, and outward for insertion into the rough inner surface of the posterior portion of the ranius of the lower jaw included between the angle and the inferior dental foramen. It is related, externally, with the ramus of the lower jaw, the external pterygoid muscle, the internal lateral ligament of the lower jaw, the lingual or gustatory nerve, and inferior dental and mylo-hyoid vessels and nerves ; internally, with the tensor palati, stylo-glossus, stylo-hyoid, posterior belly of the digastric, and the superior constrictor muscle of the pharynx. BLOOD SUPPLY. From the mylo-hyoid and internal pterygoid branches of the internal maxillary artery. NERVE SUPPLY. From the internal pterygoid branch of the inferior maxillary nerve. ACTION. Both internal pterygoid muscles acting together draw the lower jaw upward and forward ; and, singly, upward and to the opposite side. The internal maxillary artery, the larger of the two terminal branches of the external carotid, arises in the parotid gland, opposite to or slightly lower than PLATE CXLIil. Infraorbital a. Spheno-palatine a. Pterygo-palatine a. ,Vidian a. Orbita! br. Palpebral br. Anterior dental br. Nasal br. Labial br. Posterior dental a Gingival br.of posterior dental a Decending palatine a. Anterior deep temporal a External pterygoid a. Posterior deep temporal a. Small meningeal a. Middle meningeal a. Superficial temporal a . Typanic a. Deep auricular a. Internal maxillary a. External carotid a Masseteric a. Internal pterygoid a. Inferior dental a. Buccal a. Mylo hyoid a. Submental a. Mental a. Incisive br. INTERNAL MAXILLARY ARTERY AND BRANCHES, 546 FACK. ">;: the neck of the lower jaw. The artery is divided into three portions : maxillary, pterygoid, and splieno-ma x illary. Tlie j!r*t or nin.i-il/nri/ jinr/inn passes forward between tile internal lateral ligament and the neck of the lower jaw, and reaches the lower margin of the external pterygnid muscle. The mm/nl or pterygoid portion extends ohli(|Uely upward and i'orwanl upon the outer surface of the external pterygoid muscle, and is hidden hy the insertion of the temporal muscle. The flilril in- x/i/i/'iKi-iiKi.ril/iift/ /iiiiii'in lies in the spheno-maxillary fossa. In some instances the second or pterygoid portion runs entirely heneath the external pterygoid muscle, hut, hy passing hetween the two heads of that muscle, appears upon the outer surface of the muscle just before entering the spheno- maxillary fossa. The In'iini-li i if III' Jirxf nr iii tnii/mmf urt/rirx pass upward through the corresponding parts of the temporal fossa, between the temporal muscle and the pericranium, which they supply. 54S SURGICAL ,1 .V.I To MY. The /i/i ri/i/oiil branches, varying in number, supply the external and internal pterygoid muscles. The inii.-ixiti rii- /n-ni/rli, with the masseleric nerve, passes outward behind the temporal muscle through the sigmoid notch of the lower jaw to the massetcr muscle. Tlie linrraf lirnnfli accompanies the long buccal nerve in its forward course between (lie ramus of the lower jaw and the external pterygoid to the buccinator muscle. The hra IK-III x i if tin /liiril a,- xfilii no-mu.rilliirii portion are the alveolar, infra- orbital, posterior or descending palatine, Yidian, pterygo-palatine, and nas<,- palatine or spheno-palatine arteries. The ali'colar (podrrior xti/i/ r!nr rinr jim-timi, chiefly motor, are derived the anterior and posterior deep temporal nerves, the masseteric nerve, branches to the pterygoid muscles, and the long buccal nerve. The pnxftrior i/iri- *io,i, chiefly sensory, divides into three large branches: the aurieulo-temporal, the lingual (gustatory), and the inferior dental nerve. The deep temporal nerves, anterior and posterior, arise from the motor root of the fifth nerve, and ascend between the pericranium and the temporal muscle, which muscle they supply. The masseteric nerve emerges from between the external pterygoid muscle and the pterygoid ridge. It proceeds backward along the upper border. of the external pterygoid muscle : outward in front of the temporo-maxillary articulation, and through the sigmoid notch of the lower jaw, together with the masseteric artery, entering the masseter muscle, which it supplies. The branch to the internal pterygoid muscle arises from the inferior maxil- ">-2 SURGICAL ANATOMY. lary nerve before it divides : il gives off a branch to tlic otic ganglion, and enti -r- the dcr|i Mirface of the muscle. The branch to the external pterygoid muscle is. usually, a twig of tin' long buccal nerve, ami divides into two branches, which enter the deep -nirface of tin- muscle. The long buccal, a sensory nerve, is derived from the anterior portion of the inferior maxillary division of the fifth nerve. It runs between the two heads of the external pterygoid muscle, and passes downward and forward beneath the temporal muscle and the anterior edge of the masseter to the buccinator muscle. upon the outer side of which it communicates with the facial nerve and forms a plexus from which filaments pass to the adjacent mucous membrane and skin of the cheek. It contains all of the sensory libers of the anterior division of the inferior maxillary nerve, and a few fibers from the motor root of the lifth nerve. The motor fibers run to the external pterygoid and temporal muscles. The auriculo-temporal nerve arises by two roots, between which passes the middle meningeal artery. It runs backward and outward beneath the external pterygoid muscle, bet ween the internal lateral ligament and the temporo-maxillary joint, curves outward around the. neck of the condvle of the lower jaw, and pierces the upper part of the parotid gland. It next ascends over the root of the zygoma, in front of the external auditory meatus and beneath the temporal artery. In its course it receives communicating twigs from the otic ganglion, and supplies branches to the external auditory meatus, the parotid gland, and the temporo- maxillary articulation. From the parotid gland it sends a communicating branch to the temporo-faeial division of the facial nerve. It divides near the level of the tragus into the anterior auricular and superficial temporal branches. The unt< rinr auricular supplies the upper part of the pinna. The SHJH rliritil fim/>ry division of this nerve. The incision should he made through the nineous membrane of the floor of the mouth opposite the second molar tooth of the lower jaw and close to the gum, where the nerve lies immediately beneath the mucous membrane. The inferior dental nerve, the largest branch of the inferior maxillary. emerges from beneath the lower head of the external pterygoid muscle and de- scends between the internal lateral ligament and the ram us of the. lower jaw to enter the inferior dental canal. At its origin it lies internal to the inferior dental artery, which it crosses at the inferior dental foramen ; the artery is, therefore, nearer the teeth than the nerve. It is a sensory motor nerve, lying external to the lingual nerve and more superficial, the motor filaments bein.ii given off as the mylo-hyoid nerve just previous to its entrance into the inferior dental canal. The mylo-hyoid nerve is accompanied by the mylo-liyoid arterv, pierces the internal lateral ligament of the lower jaw, and descends to the mylo-hyoid groove upon the inner surface of the lower jaw. It then runs over the superficial surface of the mylo-hyoid muscle, supplying it and the anterior belly of the digastric muscle. In the interior dental canal the inferior dental nerve supplies branches to the molar and bicuspid teeth and to the gums, and divides into an incisive and a mental branch opposite the mental foramen. The incisive branch passes forward and inward in the inferior dental canal to supply the canine and incisor teeth and the adjacent region of the gum. The mental branch emerges upon the face at the mental foramen, and after communicating with the supra-maxillary branch of the facial nerve divides into several branches. These supply the mucous membrane of the lower lip and the fascia and skin of the lip and chin. The chorda tympani nerve arises from the facial in the aqueductus Fallopii, almost one-fourth of an inch above the stylo-mastoid foramen. It runs in the iter chordae posterius to the middle ear, where it passes between the handle of the malleus and the fibrous layer of the membrana tympani externally, and the mucous membrane internally. It next enters the iter chordse anterius, or canal of Huguier, to reach the pterygo-maxillary region, where it joins the outer side of the lingual nerve beneath the external pterygoid muscle. Some of its fibers leave the lingual nerve to enter the subjnaxillary ganglion and sublingual gland. The otic (Arnold's) ganglion lies upon the internal surface of the trunk of the inferior maxillary division of the fifth nerve, in front of the middle 556 SURGICAL ANATOMY. meningeal artery, and may be found by tracing any of tin- larger branches of the nerve until the root of the parent stem, near the foramen uvale. is reaelieil. tts sympathetic rool is derived from the plexus on the middle meningeal artery; its sensory rum from the inferior maxillary through the internal pterygoid nerve; its motor root from the small superficial petrosul nerve, which communicates with the tympanic branch of the glosso-pharyngeal nerve. It communicates with the auricmo-temporal and chorda tympani nerves. Motor libers of the inferior maxillary nerve pass through it to the tensor palati and tensor tympani muscles. DISSECTION. To study the first portion of the internal maxillary artery and its branches, the trunk of the inferior maxillary nerve, the origins of its branches, and the- otic ganglion, it is necessary to remove the external pterygoid muscle, the condyle of the jaw, and the remainder of the ramus as far as the transverse incision in the ramus. Fracture of the base of the skull may cause serious hemorrhage into the pterygo-maxillary region, because of rupture of the meiiingcal vessels. Lacerations of the deep temporal vessels due to cranial fracture would result in the elfusion of blood into this space, its escape above the zygoma being rendered impossible because of the attachments of the temporal fascia. Under these conditions pain on pressure made below the zygoma and behind the malar bone would be a rational symptom. Such effusion might give rise to secondary irritation of the nerves in this space. Thus, irritation of the chorda tympani nerve would cause sali- vation ; of the lingual, disturbances of sensation and laste at the end of the tongue; of the inferior dental, toothache; of the motor branches, tonic or clonic spasms of the muscles of mastication ; of the mylo-hyoid and anterior belly of the digastric muscles, more or less complete fixation of the jaw. Tumors and abscess would have similar effects, but would vary in degree in accordance with the exact location and rapidity of growth. Owing to the presence of important structures in this space, it is well to practise Hilton's method of opening a deep abscess in this region; this is done as follows: Through an incision in the skin push a grooved director into the abscess; then insert a pair of forceps along the director, and withdraw them with the blades sufficiently separated to make an opening large enough to insure good drainage. It is im- possible to do serious damage by this procedure. DISSECTION. The pterygo-maxillary region should now be thoroughly cleaned, in order to study the spheno-maxillary fissure, the pterygo-maxillary fissure, and the spheno-maxillary fossa. It will be remembered that the zygomatic fossa was mentioned in connection with the contents of the pterygo-maxillary region ; its contents have been dissected. FA CE. 557 They consist of the lower part of the temporal muscle, the internal and external pterygoid muscles, the internal maxillary artery, the inferior maxillary nerve, hranehes of the artery and nerve, and the chorda tympani nerve. The zygomatic fossa practically corresponds to the upper portion of the pterygo-maxillary region. It is hounded ahove l>y the under surface of the great wing of the sphenoid and adjacent portion of the temporal bone: in front, by the 7,ygomatic surface of the superior maxilla ; behind, by the posterior border of the pterygoid process of the sphenoid bone and the eminentia articularis ; internally, bv the external ptcrygoid plate: and externally, by the pterygoid ridge, the xvgo- matie arch, and the ranius of the inferior maxilla. At the upper and inner part of the zygomatic fossa two fissures will be observed, one horizontal, the other vertical. The horizontal fissure is the spheno-maxillary, which opens into the outer and back part of the orbit. It transmits the infra-orbital artery and vein, branches from Meckel's ganglion, and the superior maxillary nerve and its orbital branch. Its bony walls are formed, above, by the lower border of the orbital surface of the great wing of the sphenoid ; below, by the orbital surface of the superior maxilla and a portion of the palate bone ; externally, by a small part of the malar bone. It joins the pterygo-maxillary fissure at a right angle. The vertical fissure is the pterygo- maxillary, which is formed by the angle between the superior maxillary bone and the pterygoid process of the sphenoid bone. It transmits the internal maxillary artery. The spheno-maxillary fossa lies below the great wing of the sphenoid, external to the vertical portion of the palate bone, and between the orbital process of the palate bone and the zygomatic surface of the superior maxilla, in front, and the pterygoid process, behind. It contains the terminal portion of the internal maxillary artery, the branches of this portion, the superior maxillary nerve, and Meckel's ganglion. Three foramina are found in the posterior wall : the fonnmn rotundum, which transmits the superior maxillary division of the fifth nerve ; below this, the anterior opening of the Vidian canal, which transmits the Yidian nerve and vessels, and still lower the ptcrt/yo-palatine foramen the anterior opening of the pterygo-palatine canal, which transmits the pterygo-palatine vessels and the pharyngeal nerve. On the internal wall is the splifmi-jiiihitini- foramen, which transmits the spheno-palatine vessels and the naso-palatine nerve. Below the spheno-palatine foramen is the orifice of the posterior palatine canal, which trans- mits the posterior or descending palatine vessels and nerve. The superior maxillary (second division of the fifth) nerve is a sensory nerve. It arises from the Gasserian ganglion at the apex of the petrous portion of the temporal bone, passes through the foramen rotundum into the spheno- maxillary fossa, and enters the infra-orbital canal with the infra-orbital artery to 558 SURGICAL .I.V.I T<> MY. become the. infra-orbital nerve. Its branches arc: In the cranial cavity, recurrent twiyx to tlie dura mater, which communicate with liranchcs of the inferior maxillary nerve; in the spheno-maxillary fossa, orbital or temporo-malar, spheno-palatine, and jinx/i r!ur xiijn rinr
  • G1 anterior superior dental nerve is larger than the other two superior dental uerves, and arises posterior to the infra-orbital t'oraineii ; it runs downward in the anterior wall of the untrum of 1 1 ighmoiv. and supplies the im-i,r lurt/r /ni/H' two branches (inferior nasal nerve-), which pierce tin- vortical plate of the palate bone tn supply the mumus membrane of the hack part ui' the middle and inlerinr ineatuses ami the inferior turhinated hone. The external or niit/ii!'it!iif nerve (nerve of Cotunnius), the largest of these brandies, runs downward and forward on the septum of the nose, between the periosteum and the mucous membrane, to the anterior palatine canal, where it passes through one of the foramina of Scarpa (subdivisions of the anterior palatine foramen) to supply the mucous membrane of the anterior portion of the hard palate and to join the terminal portion of the anterior palatine nerve. The superior /mxnl nerves are several twigs which pass through the spheno- palatine foramen to supply the mucous membrane of the posterior part of the middle and superior turbinated bones, and of the posterior ethmoid cells and antrum of Highmore. The posterior branch is the pharyngeal nerve. The pharyngeal or pterygo-palatine nerve runs backward through the pterygo-palatine canal in company with the pterygo-palatine artery; it supplies the upper portion of the pharynx and the Eustachian tube. The Vidian nerve has been considered a posterior branch of the spheno- palatine ganglion, but it is really the nerve which is formed by the junction of its motor and sympathetic roots. It will be seen emerging from the Yidian canal at the root of the pterygoid process. The superior maxillary nerve and its many communications are especially important, because it is so frequently affected by neuralgia, the operation for which follows. Trifacial neuralgia may be due to many causes ; among these are : Reflected irritation from diseased teeth, eruption of the wisdom teeth, irritable ulcers in the FACE. area of distribution of the nerve, ami abscess or tumors of the antruni of Iliglnnore, of the ptcrygo-niaxillary region, or of the spheno-maxillary fossa. Tlie infra-orbital foramen is on a line drawn from the supra-orbital notch to a point between the bicuspid teeth of the upper jaw. It corresponds to a point ahont one-half of an inch below the junction of the inner and the middle one-third of the infra-orbital margin. The infra-orbital nerve is best exposed through a semilnnar incision with iN convexitv directed downward, and carried a short distance below the foramen. A Hap, including skin, cellular tissue, and the orbicnlaris palpebrarum muscle, is raised. The levator labii superioris muscle, which covers the foramen, is now apparent, and mu>t he displaced laterally or divided, when both the infra-oijiital plexus and nerve will readily be found, surrounded by a small quantity of fatty tissue. In some cases of obstinate neuralgia of the peripheral branches of the trifacial nerve it becomes necessary to remove a portion of the affected nerve in order to give the patient relief. The infra-orbital nerve may be divided at its exit from the infra-orbital foramen by either a subcutaneous or a conjunctiva! section; in the hitler method the tenotome is introduced through the conjunctiva and carried over the infra-orbital margin ; it is best to expose the infra-orbital nerve by turning up a flap from the face, when a portion of the nerve can be removed. The nerve being exposed and freed at its point of exit, a slightly curved or hooked knife can be entered close to the external canthus just below the outer palpebral ligament, and passed backward along the floor of the orbit toward the apex, and along the anterior border of the spheno-maxillary fissure, which is crossed by the nerve at about an inch behind the orbital margin. The knife is then carefully withdrawn, and the nerve divided as it enters the infra- orbital canal. Traction is then made upon the peripheral end of the nerve to remove it from the infra-orbital canal. Should the knife be carried too far and the spheno-maxillary fossa be entered, serious hemorrhage would result. The objections to this last method are, first, the hemorrhage which results from the division of the infra-orbital vessels inaccessible for ligature; second, the uncertainty of accomplishing the division of the nerve ; and third, in many of these cases the posterior, as well as the anterior, dental branches are involved ; if this be the case, removal of the superior maxillary nerve behind Meckel's ganglion will be required in order to insure positive relief. The best method for removing the superior maxillary nerve through the face from behind Meckel's ganglion is the following: Expose and free the infra-orbital nerve at its exit from the infra-orbital foramen ; then, with a three-quarter-inch trephine, remove a button of bone from the anterior wall of the antrum of High- more ; this button should include the outer wall of the infra-orbital foramen, and SURGICAL ANATOMY. in removing it can 1 must lie taken not to sever the infra-orbital nerve. Open the antruni hy tearing through the lining membrane, and then, with a trephine one- half of an inch in diameter or with a small chisel, perforate its posterior wall. This opens up tin- spheno-maxillary fossa, and will be followed hy considerahle bleeding from wounded brandies of tlie internal maxillary vessels. Before pro- ceeding with tlie next step in the operation pack the opening in the posterior wall with sterile gauze to cheek the hemorrhage; then, with a small chisel, break away the tloor of the infra-orbital canal and the back part of the lloor of the orbit along the roof of the antruni ; this permits the infra-orbital nerve to be drawn down into the antruni, when, bv making slight traction upon it, a pair of long, slender scissors, sharply curved and with blunt points, can be carried along the nerve through the antrum, and the superior maxillary nerve divided behind Meckel's ganglion. In breaking away the floor of the infra-orbital canal the infra-orbital vessels will be torn, but the bleeding therefrom is of no serious consequence and can be controlled by packing a strip of sterile gauze into the broken canal. If hemorrhage persist after the removal of the superior maxillary nerve, the spheno-maxillary fossa also may be packed with gauze, which should protrude through the opening in the anterior wall of the antrum. The gauze may remain for two or three days and serves a two-fold purpose: in controlling the bleeding and in favoring drainage. The operation is facilitated by the use of an incandescent lamp attached to a head-band. Clavus (nail) is the name given to a neuralgic pain, which, from its intensity and the smallness of its area, is likened to a nail being driven through the flesh and bone. It generally affects hysteric voting women. It is not inappropriate for the author to say here that, having had a large experience in the operative 1 treatment of cases of trigeminal neuralgia (tie doulou- reux), he is of the opinion that the simpler operative procedure should first be pursued, for the period of relief following any operation is, comparatively speak- ing, lint temporary in the majority of cases. This is not in accord with the views of some of the leading operators, but it has, nevertheless, been the author's experi- ence. He has operated on a number of cases several times, in one instance as many as five, each operation having been followed by relief for from twelve to eighteen months. The peripheral operations may be repeated, a little more of the nerve being removed at each operation. This course affords the patient a more prolonged period of relief than could be obtained by first performing the more- radical operation. As a last resort, the most radical operation of all, intra-cranial section of the affected nerve or removal of the Gasserian ganglion, may be done. In cases where 1 tlie neuralgia, has returned after removal of the superior maxillary nerve back of Meckel's ganglion by opening both walls of the antrum anel removing FACE. r,<;.-> the infra-orbital nerve from its canal, Ilie author luis, by simply cleaning out the track of the original wound, seen relief follow. In trifaeial neuralgia one, two, or all three branches of the trifaeial nerve may be involved. The ophthalmic division supplies the skin above the palpebral fissure; the superior maxillary division, the skin between the palpebral and oral fissures, including the temple; the inferior maxillary division supplies the skin below the oral fissure as far as the hyoid bone. The superior and the interior maxillary nerves also supply the teeth through their branches, while the latter supplies the anterior two-thirds of the tongue through its lingual branch; the motor root of the third division also supplies the muscles of ma: tie.-ition, except the buccinator /. c., the temporal, rnasseter, and external and internal pterygoid muscles. Thus, cunijilrt,' jxirnl ijxix of the trifaeial nerve abolishes sensation upon one side of the fact' and on top of the head, from the highest point of the vertex above to the hyoid bone below ; laterally, to and including the front of the ear and external auditory canal and temple; mesially, the anterior nares and the sensibility as to touch and taste of the anterior two-thirds of the tongue, besides completely paralyzing the muscles of mastication on the affected side, with the exception of the buccinator. Because of the insensibility of the conjunctiva the lids do not properly protect this mem- brane, and it becomes congested and inflamed, a condition which often occurs spontaneously through implication of the trophic fibers of the trifaeial nerve. At the same time anterior rhinitis may result from similar causes, or may be excited by the discharge of the conjunctival secretion into the inferior nieatus of the nose. Trifaeial neuralgia may be accompanied by active implication of the trophic filaments, so that there is not only conjunctivitis and rhinitis, but vesicles may form upon the lips and anterior nares. This should be borne in mind, as these trophic nerve disturbances, when overlooked, may be the source of much per- plexity to the physician, and may lose him a desirable patient. Paralysis of the orbicularis palpebrarum muscle also leads to conjunctivitis, from inability to close the eyelids ; this must not be confounded with the inflam- mation of perverted function of the trophic nerves. The trophic filaments are derived from the sympathetic nerve ; this is a general rule worth remembering. The entire width of the occiput, as high up as the vertex, and the back of the pinna are supplied by the occipitalis major nerve. As Hilton pointed out, the pinna, may, therefore, often be used to differentiate between spinal and cerebral central nerve disease causing neuralgia ; if spinal, the back of the pinna is affected and the front is not ; if cerebral, the signs are reversed. Reflex or referred pains are frequent in the area of distribution of the trifaeial 566 SURGICAL . I. \.\T<) MY. nerve because nt' llie abundance of its lilameiit> and tlioir numerous inosculations. Tbc ])liysician must, therefore, lie ea refill not to be misled by tbe location of pain, for an earache may lie due to a diseased tooth, as was the case in a patient treated by Hilton: The patient had consulted several leading aurists for ,-i persistent earache without obtaining relief except from the use of anodynes; the ingenior.s Hilton sagaciously concluded it to be useless to treat where so many others had (ailed, and looked elsewhere than at the ear for the cause of the trouble. This he found in a jagged molar tooth which was continually irritating a .small nerve filament at the bottom of an ulcer upon the side of the tongue adjoining the tooth. lie advised the removal of the tooth, which resulted in healing of the ulcer and in cure of the earache. In a similar manner affections of any filament of the trifacial nerve may produce pain in any part supplied by other branches of the nerve. The Lymphatic Glands of the Head are divided into a superficial and a deep set. The superficial set is composed of the occipital, posterior auricular, parotid, buccal, and submaxillary lymphatic glands. The occipital or suboccipital lymphatic glands arc situated in the superficial fascia along the superior curved line of the occipital bone over the attachments of the trape/.ius muscle and the occipital belly of the occipito-frontalis muscle. These glands receive the lymphatic vessels from the posterior portion of the scalp or that area supplied by the occipital artery, and may be involved in erysipelas or other septic conditions of the posterior portion of the scalp. The efferent vessels from these glands empty into the superficial lymphatic glands of the neck. The posterior auricular or mastoid lymphatic glands are situated behind the pinna, over the mastoid process and the insertion of the sterno-mastoid muscle. They receive the lymphatic vessels from the posterior auricular region and the portion of the scalp above it. Their efferent vessels empty into the superficial lymphatic glands of the neck. The parotid lymphatic glands lie upon the parotid salivary gland in front of the pinna, below the zygoma, and a few are found in the substance of the parotid salivary gland. They receive the lymphatic vessels from the temporal region, the portion of the scalp above it, and the outer portion of the eyelids and of the cheek. Their efferent vessels empty into the superficial lymphatic glands of the neck and into the submaxillary lymphatic glands. The buccal lymphatic glands rest upon the buccinator muscle. They receive some of the lymphatics from the anterior portion of the face, inner half of the eyelids, brow, and front of the scalp. Their efferent vessels empty into the submaxillary and the internal maxillary lymphatic glands. The submaxillary lymphatic glands are the largest group. They are FACE. 567 situated below the border of the lower jaw, most of them lying in tlie submaxillary triangle in relation with tlie submaxillary salisary gland ; two or tlnve of them (Mipra-hyoid lymphatics) lie above (he body of the hyoid hone, between the ante- rior bellies of the two digastric museles. The subma x illary ly mphat ie glands, receive the lymphatic vessels from the front of the >calp, inner part of the eyelids, anterior portion of the face, floor of the mouth, anterior portion of the tongue, snblingual and submaxillary salivary glands, and some of the efferent vessels from the parotid lymphatic glands. Their efferent vessels empty into the superficial and deep cervical lymphatic glands. The deep lymphatic glands of the head are the internal maxillary, lingual, and post-pharyngeal lymphatic glands. The internal maxillary lymphatic glands are situated in the pterygo-maxil- lary region : some are in relation with the internal maxillary artery, others lie upon the posterior portion of the buccinator muscle, ami still other deep glands lie upon the side of the pharynx. They receive the lymphatic vessels from the orbi- tal, nasal, temporal, and zygomatic fossa 1 , the roof of the mouth, and tlie soft palate, and some of tlie efferent vessels from the buceal lymphatic glands. Their efferent vessels empty into the deep cervical lymphatic glands and partly into the deep parotid lymphatic glands. The lingual lymphatic glands lie upon the hyo-glossus and genio-hyo-glossus muscles. They receive the lymphatic vessels from the upper surface and posterior part of the tongue. Their efferent vessels unite with the upper glands of the deep cervical chain. The post-pharyngeal lymphatic gland is situated below the base of the skull, between the posterior wall of the pharynx and the rectus eapitis anticus major muscle. It receives the lymphatic vessels from the upper part of the pharynx, part of the nasal fossa, and the upper part of the prevertebral museles. The lymphatic vessels of the scalp, which drain that portion behind a ver- tical line passing through the external auditory nieatus, terminate in the occipital and posterior auricular lymphatic glands ; the lymphatics of the temporal region of the scalp and that portion above it empty into the superficial and deep parotid lymphatic glands; the lymphatic vessels of the frontal region of the scalp follow the frontal, supra-orbital, and the facial veins downward over the face to the sub- maxillary lymphatic glands. The lymphatic vessels of the face are divided into a superficial and a deep set. The superficial lymphatics of the anterior portion of the face /. e., of the inner half of the eyelids, of the nose, lips, and anterior part of the cheek pass downward into the submaxillary lymphatic glands, and those of the outer half of 568 SURGICAL ,1 \.\Tf >MY. the eyelids and outer part of the check Icrminnle in the parotid lymphatic glands. The VESSELS <>!' THE BRAIN. 571 however, in diU'erent subjects (Merkel). These veins arc distinct before the eranial hones unite with one another, after which there isa I'rec anastomosis between them. In young subjects they are small, but they increase in si/.c as age advances (Quain). They have no valves, and their walls are exiivinelx thin. The frontal veins are situated in the anterior part of the frontal hone: they pass most frequently through the sii]ira-orhital foramen and empty into the supra- orbital vein ; they may, however, empty into the fronto-spheiioid vein. Yaricosity ot' this vein, even to the extent of causing absorption of the outer table of the bone, may occur. The fronto-sphenoid veins lie in the lateral part of the frontal and in the sphenoid bone: they empty into the sinus ahe parva-. The fronto-parietal or anterior temporal veins are situated in the posterior part of the frontal and in the anterior part of the parietal bone : externally they empty into the deep temporal veins, and internally into the superior petrosal sinus or a meiiingeal vein. The external parietal or posterior temporal vein is situated in the parietal bone : it passes through a foramen in the posterior inferior angle of this bone, or through the mastoid foramen to empty into the lateral sinus. The occipital or parieto-occipital vein, the largest of the diploic veins, is con- fined to the occipital bone; it empties externally into the occipital vein, or inter- nally into the lateral sinus. In compound fractures of the skull the diploic veins offer an opening favor- able to the introduction of septic matter into the circulation, thereby permitting thrombosis of the sinuses, septic meningitis, general sepsis (pyemia), or, possibly, abscess of other organs, especially the liver. The diploic veins communicate with those of the scalp by means of very small vessels; through these the septic matter may be conveyed to the diploic veins and thence to the sinuses. It is doubtless through one or more of these emissary veins, in the majority of cases, that septic material the result of inflammation of the scalp enters the venous system. DISSECTION. Remove the calvaria (skull cap) by sawing through the outer and middle tables along a line carried horizontally around the skull, connecting a point one-half of an inch above the supra-orbital margin with a point the same distance ahove the external occipital protuberance; then, with a chisel and mallet, cut through the inner table, prying the calvaria from the underlying dura mater. In breaking through the inner table the mallet and chisel are preferred to the saw, there being less danger of cutting the dura mater: even when closely adhe- rent to the calvaria, the dura mater should only be divided as a last resort. In dividing the bone in the temporal region its thinness must be borne in mind, otherwise the brain, as well as the dura mater, may be injured. 572 SURGICAL ANATOMY. Pacchionian bodies. The outer surface nf the dura mater being exposed by removal of the skull cap. it appear- rough, especially along the lines of the sutures iiid in the neighborhood of the foramina, where- it is moM closely attached to the IIOIK-. The anterior and posterior branches of the middle meningeal artery, with the corresponding veins, will be seen to r;iiuifv upon the dura mater over each hemisphere; in most instances granular masses, (he 1'acchionian bodies, which are villous processes of the arachnoid, will he observed upon the surface on each side of the middle line. The position of these bodies should be carefully noted, and they must not be regarded as pathologic when seen on the operating or postmortem table. In some cases they are <|uite large: the author has known one to be so large as t jcasion sufficient pressure to give rise to focal (Jacksonian) epilepsy ; the patient was trephined, and the enlarged 1'acchionian body with the underlying cerebral cortex removed, in the belief that it was a neoplasm. The convulsions were arrested temporarily, but returned after a time: this, unfortunately, occurs in the majority of cases of Jacksonian epilepsy operated upon. These bodies are always impressed upon the oalvaria, so that depressions, corresponding in size to the bulk of the bodies causing them, may be seen upon each side of the median line of the skull; at times they almost perforate the bone. As a rule, they hollow the bone out sulliciciitly to render it translucent. The existence of these bodies may, there- fore, be ascertained by inspection of the interior of the oalvaria, and it is even pos- sible, by the aid of transmitted light, to determine their presence by examining from without. The Pacchionian bodies, as previously slated, are processes of the arachnoid, and serve as channels for the passage of the cerebro-spinal fluid into the venous sinuses of the dura mater; in this way they relieve intra-cranial pressure. They vary greatly in si/<- in different persons, and in children are quite small. The dura mater, the most external of the three membranes of the brain, forms the internal periosteum of the skull, and affords an excellent protection to the brain. Through the medium of this internal periosteum the bones of the skull receive the greater part of their nourishment; this explains why they seldom necrose in scalp wounds in which the pericranium or external periosteum is torn away. The dura mater is a dense, tough, inelastic, fibrous membrane. It is inti- mately adherent to the base of the skull, 'owing, partly, to the numerous foramina found there; therefore, extra-dural extravasations or collections of blood or pus between the dura and skull rarely, if ever, occur at the base of the skull ; at the sides and roof of the cranial cavity, however, where the membrane is com- paratively loosely attached (except along the sutures and around the foramina), purulent collections and extravasations from rupture of one or both branches of the middle meningeal artery are not uncommon. These conditions cause compression of the brain, the symptoms of which, coming on immediately after PLATE CXLVIII, Orifice of superior cerebral v Dura Frontal Sinuses Mat Arachnoid Dura Mater Middle meningeal a Pacchionian bodies Superior cerebral v. Superior longitudinal sinus DURA MATER, ARACHNOID, AND MENINGEAL VESSELS. 573 y///; .i//;.]//;/,'.i.\7-;s A\J> VI-WELS OF THE BRAIX. 575 an injury to the head, indicate depressed fracture: it' they appear a short tinu' then-after, hemorrhage : some days after, pus. Tillaux lias demonstrated that the dura mater is less firmly attached to the t-emporal t'ussa. the most l're([Uent site of extra-dural hemorrhage, than to any other portion of the interior of the skull (Treves). It is most closely adherent to the hone in infancy and old age. It has been demonstrated by Sir Charles Hell that the dura mater may he separated from the vault and sides of the skull by striking the head of a cadaver a hard blow with a heavy mallet. Extra-dural hemorrhage. The most common canse of extra-dural hemorrhage is rupture of the branches of the middle meningeal artery; this is usually associ- ated with fracture of the parietal bone at its anterior inferior angle, the site of the groove through which the anterior branch of the artery passes. The author has trephined for compression of the brain produced by an extra-dural clot not asso- ciated with fracture. The next most frequent source of extra-dural hemorrhage is the lateral sinus. Attachments of the dura mater.- Hesides being closely adherent to the base of the skull, the dura mater is continuous, through the optic foramen, with the periosteum of the orbit; through the foramen magnum, with the dura mater of the spinal canal ; and through the lissnres and the various foramina through which the vessels and nerves enter and leave the cranial cavity, clothed by prolongations of this membrane, with the pericranium. As the dura mater is directly continuous with these various structures, it can be readily understood how inflammation may extend by continuity into the cranial cavity and cause secondary meningitis. Pulsations of the dura mater. The dura mater, when exposed in the living subject, may present two distinct pulsations, communicated from the underlying brain : one synchronous with the pulsation of the arteries, the other with respira- tion, rising in expiration and sinking in inspiration. Layers of the dura mater. The dura mater consists of two layers : an outer, the endosteal, and an inner, the meningeal; the latter is lined by endothelium, which gives it its shiny appearance. Between the two layers venous channels or sinuses and the (Jasserian ganglion are found. The inner or meningeal layer -ends in partitions which separate and support the different portions of the brain. Sarcomata of the dura mater may protrude through the bones of the cranium and cause a swelling in the scalp. DISSECTION. Preliminary to removing the brain, and in order to obtain the most correct idea of the normal relations of the two larger partitions formed by the inner layer, namely, the falx cerebri and the tentorium cerebelli, divide the dura mater in the following manner: Carry two incisions through it from before 576 SI-J!H/r,\i. ANATOMY. backward, one-half of an inch on cadi side of tin- median lino, thus avoiding the superior longitudinal sinus. From the center of those incisions carry a transverse incision upon eaoli side as far as the divided margin of the hone. Ueilect the Haps thus made, and with the lingers gently sejmrate the hemispheres of the cerebrum. The falx eerohri, with the veins from the surface of the eeivl>nim which empty into (lie superior longitudinal sinus, may then be seen. The tontorium cerelielli can no\v lie readily exposed hy lifting up the posterior extremities of the hemi- spheres of the cerelinun (occipital lobes). Next lay open the superior longitudinal sinus and inspect its interior. The small openings of the veins from the top of the hemispheres (superior cerebral veins), the diploe, and the dura mater will be seen along its entire course : they generally enter from behind forward. Divide the anterior uncut portion of the dura mater, and sever the falx eorebri from its attachment to the crista galli, along with the veins which empty into the superior longitudinal sinus ; together with the falx cerebri turn back the strip of dura mater in which is contained the superior longitudinal sinus. Removal of the brain. The brain should now be removed in the following manner : Draw the subject well up so that the head will hang over the edge of the table. With the lingers of the loft hand lift the frontal lobes of the cerebrum from the anterior cranial fossa and raise the olfactory bulbs from the cribriform plate of the ethmoid bone, thus severing the olfactory nerves. The optic nerves with the oph- thalmic arteries beneath will now be seen, and both should be cut across (preferably with scissors), a short distance from the brain. By gently lifting and displacing the hemispheres backward, the infernal carotid arteries and the infundibulum (a pro- cess of gray matter which connects the pituitary body with the tuber cinereum) will be seen. These should next be divided or the artery should be severed and the pituitary body removed from the pituitary fossa after incising the diaphragma sellre. The third pair of cranial nerves, the oculo-motor, will be seen lying behind the anterior clinoid processes on their way to reach the cavernous sinuses. Divide those nerves and then, turning the head to the right, lift the temporo- sphenoid lobes from the middle cranial fossa, and the tentorium cerebelli will be brought into view. This should be cut through close to its attachment to the posterior clinoid process and to the petrous portion of the temporal bone. The pathetic, or fourth, and the trifacial, or fifth, pairs of cranial nerves should be severed on the left side ; turn the head to the left, and divide the corresponding structures on the right side. Bring the face back to the middle line, draw the brain well backward, and divide the following structures from within outward in the order named : The abducens or sixth, the facial or seventh, the audi- tory or eighth, the glosso-pharyngeal or ninth, the pneumogastric or vagus or 37 PLATE CXL1X, Veins of Galen Straight sinus Middle meningeal a. Inferior longitudinal sinus Falx cerebrl Superior longitudinal sinus Falx cerebell Lateral sinus Tentorium cerebeMi Inferior petrosal sinus Nasal septum Circular sinus Transverse sinus SINUSES AND PROCESSES OF DURA MATER. 578 PLATE CL Optic n 6th n Motor oculi n 4th n Opthalmic division of 5th n. Superior maxillary n. Gasserian ganglion Inferior maxillary n. Foramen caecum r Crista galli Pituitary body Circular sinus ^Internal carotid a, Opthalmic a. ,Cavernous sinus .Middle meningeal a. Superior petrosal sinus 5th n Lateral sinus Sigmoid sinus Inferior petrosal sinus Transverse sinus Basilar plexus Occipital sinus Superior longitudinal sinus SINUSES AND CRANIAL NERVES. 579 THE MEMBRANES AND VESSELS OF THE JWALV. 581 tenth, the spinal accessory or eleventh, and the hypo-glossal or twelfth pair of cranial nerves. The next and iinal step consists of carrying a scalpel down into the spinal canal as far as possible and cutting through the spinal cord, the two vertebral arteries, and the spinal portions of the spinal accessory nerves. The fingers of the right hand should then be slipped beneath the cerebellum and pons, and the brain removed. Preservation of the brain. If the brain be not dissected at once, it should be placed in a solution of chlorid of zinc, in alcohol and formaldehyd, or Miiller's fluid. If placed in the zinc solution, the pia mater should be removed later, for if allowed to remain in this solution for some time, it is more easily separated than in the fresh condition. If alcohol alone be used to preserve the brain, the pia mater must be removed before placing it therein ; this is most readily done under water ; but if preserved in alcohol and formaldehyd, the membrane may be removed at leisure. Brains hardened in chlorid of zinc should afterward be kept in alcohol. When the brain has been removed from a subject injected (embalmed) with chlorid of zinc, the pia mater can at once be separated and the brain placed in alcohol. If the brain from a fresh subject be immediately placed in alcohol, subsequent removal of the pia mater will be found almost impossible on account of its firm adherence. If the pia mater is not removed, the study of the convolutions is much less satisfactory. Brains which have been hardened in chlorid of zinc and afterward kept in alcohol are much easier to handle than when kept in zinc alone, as the latter, by its action on the skin, makes the fingers sticky. Brains preserved in alcohol and formaldehyd are preferable to those preserved in a solution of zinc chlorid and alcohol, because they are not shrunken so much as the latter. Brains taken from a subject embalmed with zinc chlorid should be hardened in a solution of the same ; only fresh brains should be hardened and preserved in alcohol and a two per cent, solution of formaldehyd. Processes of the dura mater. The dura mater, through duplication of its inner or meningeal layer, sends three larger and five smaller partitions, folds, or processes into the cavity of the skull and between certain divisions of the brain ; these afford support to the latter. The three larger processes are the falx cerebri, the tentorium cerebelli, and the falx cci-clx-lli. The five smaller processes or folds comprise two pairs and a single one. Of the two pairs, the larger are attached to the lesser wings of the sphenoid bone and project into the Sylvian fissure. The smaller pair, crescentic in shape, are attached to the clinoid processes and over- hang the optic nerves. The single fold of the smaller group stretches across the pituitary fossa covering the pituitary body, and is known as the diaphragm of the pituitary fossa, or diaphragma sellse. Its center contains an opening for the passage of the infundibulum. 582 SURGICAL ANATOMY. The falx cerebri is a sickle-shaped process, narrowed almost to a point in front. where it is attached to the erista galli ; it is broad hehind, where it is attached to the middle of the upper surface of the tentoriuin cerebclli. Jt projects into ihe great longitudinal fissure of the brain and separates ihe hemispheres of the cere- brum. Its convex upper border is attached upon the inner surface of the calvaria to the edges of the groove which accommodates the superior longitudinal sinus. The concave lower border is free, arches over the corpus callosum. and contains the inferior longitudinal sinus. The tentorium eerebelli is a somewhat triangular-shaped process, having its base attached upon the inner surface of the occipital bone to the edges of the groove for the lateral sinuses ; the sides are attached to the line of junction of the upper and posterior surfaces of the petrous portion of the temporal bone, from the apex of which they a re continued to the posterior and anterior clinoid processes. The apex corresponds to the free edge, which forms the lateral and posterior boun- daries of the triangular opening known as the tuijifrior nrri/iitiil J'oriinn n nr mijtrriur fiti'iin a n IIKII/IIIIIII. This foramen gives passage to the crura eerebri, the superior peduncles of the cerebellum, the oculo-motor and pathetic nerves, and the basilar artery. The tentorium eerebelli projects into the great transverse fissure of the brain ami separates the posterior lobes of the cerebrum from the cerebellum. In the convex border of the base of the tentorium eerebelli the horizontal portions of the lateral sinuses are contained ; in the sides, the superior petrosal sinuses ; and in the middle, at its union with the falx cerebri, the straight sinus. The base of the falx cerebri is attached along the entire median line of the upper surface of the tentorium eerebelli, and the falx eerebelli to the median line of the lower surface. The tentorium serves to support the posterior lobes of the cerebrum, thus protecting the cerebellum from pressure. The falx eerebelli is a small, vertical fold attached posteriorly to the internal occipital crest or inferior vertical limb of the occipital cross, and above to the under surface of the tentorium ce rebel li : it is situated between the hemispheres of the cerebellum. In its posterior border is contained the occipital sinus. This border at times splits into two parts, which are attached to the sides of the back part of the foramen magnum. Sinuses of the dura mater. The sinuses of the dura mater are venous chan- nels formed by the separation of its endosteal and meningeal layers, and are lined by a prolongation of the lining membrane of the veins. They are rigid tubes, which always remain patent (Macewen) ; their function is to return the venous blood from the brain and its coverings, the diploe (with a few exceptions), and also the greater part of the blood from the orbit and eyeball. They collect this blood and convey it to the jugular or posterior lacerated foramina, where it is taken THE MEMBRANES AND VESSELS OF THE BRA IX. 583 up by the internal jugular veins. There are sixteen in all, and they consist of two groups: those situated at the upper and haek part of the cranial cavity, and those situated at the base of the skull. The former group includes the superior longitudinal, the inferior longitudinal, the straight, the lateral, and the occipital sinuses. The last-named group includes the cavernous, the sinuses al;e parv;e, the circular, the superior petrosal, the inferior petrosal, and the transverse. They can also be divided into a median and a lateral group, the former including the single sinuses, situated in the middle line of the skull, and the latter the paired sinuses, situated on both sides of the middle line. Five are in pairs and six are single. The five pairs are the lateral, the superior petrosal, the inferior petrosal, the cavernous, and the sinuses alae parvie. The six single sinuses are the superior longitudinal, the inferior longitudinal, the circular, the transverse, the straight, and the occipital. Some anatomists describe the sigmoid portions of the lateral sinuses as an additional pair, thus making the number eighteen. The superior longitudinal sinus, which has already been exposed, occupies the convex border of the falx cerebri. It passes from the foramen ctceuni at the root of the frontal crest through the mesial groove on the inner surface of the cal- varia ; deviating slightly to the right in the posterior part of its course, it runs to the internal occipital protuberance, to end in the torcular Herophili. The Inmihir Hcmpldli is the point of confluence of the superior longitudinal, lateral, straight, and occipital sinuses, and is situated a little to the right of the internal occipital protuberance. The superior longitudinal sinus is triangular on section, the base being directed toward the calvaria ; it is narrower in front, gradually increasing in width as it passes backward. Its lumen is crossed by a number of fibrous bands, the chordae WHIixii, and Pacchionian bodies are frequently found projecting into it. It receives veins from the scalp through the parietal foramina, from the diploe, the dura mater, and the hemispheres of the cerebrum. These veins, particularly those from the cerebrum, the superior cortical, run into the sinus from behind forward in the direction opposite to that in which the blood current passes ; furthermore, they pierce the wall of the sinus very obliquely. In the fetus the sinus com- municates with the veins of the nose by a small emissary vein which passes through the foramen cajcum, but this seldom occurs in the adult. The superior longitudinal sinus presents a variable number of lateral outgrowths or pouches, which have been named the lacunas laterales. It is into these that the Pacchi- onian bodies project. Wounds of, and line for, the superior longitudinal sinus. The relation of the sinus to the skull renders it likely to be wounded in compound fracture of the vertex, and in trephining operations over the median line of the vertex. Hemor- rhage from this or any of the sinuses is best controlled by plugging with sterile 584 SURGICAL .-I .Y.I ToMY. gauze, unless the wound be small, iu which case it can he closed hy sutures. The course of Hie sinus is represented on the scalp hy a straight line drawn from the root of the nose over the median line of the vertex to the external occipital protuberance. Septic or infective processes of the scalp may enter the superior longitudinal sinus through the parietal emissary veins ; septic processes of the nose may reach that sinus through the vein in which the sinus has its. origin. The lateral sinuses, the largest of the cranial sinuses, extend from the internal occipital protuberance to the jugular foramina, terminating at the begin- ning of the internal jugular veins. They arise on each side of the internal occipital protuberance, across which they are connected by a small branch ; thence they pass outward and forward, grooving the squamous portion of the occipital, the posterior inferior angle of the parietal, the mastoid portion of the temporal, and the jugular process of the occipital bone. Each sinus consists of two portions, a horizontal and a sigmoid. The linrr.niiliil /xir/io/i is situated in the base of the tentoriuni cerebelli ; it is triangular on section, the base of the triangle being directed toward the occipital bone and the posterior inferior angle of the parietal bone. The nii/nmiiJ jujiiinii is situated below the tentoriuni cerebelli, and grooves the mastoid portion of the temporal and the jugular process of the occipital bone; it is seniicylindric on section, and is considered by some anatomists a separate sinus the sigmoid. The superior petrosal sinus empties posteriorly into the sigmoid portion of the lateral sinus at its origin. The lateral sinus varies somewhat in size and position, a fact to be remembered in trephining operations. Tri/n't'/i-iix i if tin lufi rut ximiK. The right lateral sinus is usually larger than the left; it begins at the torcular Herophili, and is the continuation of the superior longitudinal sinus. The left lateral sinus is the continuation of the straight sinus. In addition to the superior petrosal sinuses, the lateral sinuses receive emissary veins IVom the scalp, which pass through the mastoid and pos- terior condyloid foramina ; veins from the diploe (the occipital and the external parietal); the lateral inferior cerebral, and some of the superior and inferior cerehellar veins. Leeching. A suitable site for applying leeches in meningitis is behind the ear; in this way blood is extracted directly from the lateral sinus through the mastoid emissary vein, thus depleting the intra-craiiial circulation. Another, but less favorable, location for the application of leeches in meningitis is near the inner cauthus of the eye, where the angular vein anastomoses with the ophthalmic vein. Thrombosis of the lateral sinus. The sigmoid portion of the lateral sinus, or thi' sigmoid sinus, is the portion of the intra-cranial venous circulation most con- PLATE CLI. Bregma Lower level: of Cerebrum LINES FOR SINUSES. 585 Till': M !:.}[ in; A \i-:s AXD iv-7-;/.N or TUP: BHAIX. 587 cerned in disi',-i-rs of the middle car. Thrombosis of this portion of the sinus and of tin- commencement (>!' the internal jugular vein constitutes one of the complica- tions of snppnrative middle ear disease, and is due to the proximity of the sinus to the middle ear and mastoid cells, and to the fact that veins pass directly from the mastoid portion of the temporal hone to the lateral sinus. This condition demands exposure of the sinus and removal of the clot; this is hest done hefoiv general systemic infection has occurred. When sepsis is present and the mastoid antrum has hecii drained by trephining the mastoid process without producing the desired ell'ect, the sigmoid portion of the lateral sinus should he exposed without delay. The presence of a clot can readily he determined by palpation ; removal of the clot should immediately he followed hy antiseptic packing of the sinus. The four most serious complications of suppurative otit is media are septic thrombosis of the lateral sinus, septic meningitis, abscess of the temporo-sphenoid lobe of the cerebrum, and ccrebellar abscess. Infective processes may also reach the lateral sinus from the scalp through the mastoid vein, occipital diploic and posterior temporal diploic veins, and through the superior longitudinal and the cavernous sinus. Line for the lateral sinus.- In trephining for depressed fracture of the occipital bone, ccivbellar tumor, cerebellar abscess; in opening the mastoid cells or mastoid antrum ; or in exposing the sinus itself in septic thrombosis, it is highly important to bear in mind the relation of the lateral sinus to the exterior of the skull. Its course is represented as follows: Draw a line from the external occipital protuberance to a point an inch above the external auditor}' meatus. The sinus follows this line as far as the base of the mastoid process ; thence it runs downward in the middle line of the mastoid to its apex. According to Macewcn, the right sigmoid groove is generally wider and deeper, projects farther outward, and reaches farther forward .than the left sigmoid groove. The closer proximity of the sigmoid portion of the right lateral sinus to the middle ear perhaps explains the greater frequency of Ultra-cranial lesions consecutive to right-sided otit is media. Operations on the mastoid process. In opening the mastoid cells or mastoid antrum it is better to expose the entire surface of the mastoid process by turning up a large flap, than to expose a limited surface through a vertical incision behind the ear ; this is particularly the case if the disease be advanced, when the overlying soft parts become so swollen as to render it impossible to outline the process with any degree of certainty. When the mastoid process is exposed, draw two lines a hori- zontal one through the roof of the external auditory meatus, and a vertical one through its posterior wall. In adults apply the trephine or gouge at a point a little below the horizontal and behind the perpendicular line ; in children apply 588 SURGICAL .-\\.\TOMY. the instrument at a point directly over the horizontal and behind the perpendicu- lar line. With the trephine or gouge make an opening in a forward and inward direction. Having removed the external table, the mastoid antrnni can usually be entered with a. small elevator or a stilt' director; this is to be preferred to the trephine or goug>, as it lessens the risk of injuring the sigmoid portion of the lateral sinus. Moth the tympanum, or middle ear, and the mastoid cells can be drained through the mastoid aiitrum. In the majority of cases the pus is primarily in the tympanum, yet occasionally suppuration takes place oriffine in the mastoid cells. It must not be forgotten that in children and in many adults there are no well-developed mastoid cells; opening directly into the mastoid ant rum is, therefore, the safest course to pursue in all cases. The inferior longitudinal sinus is situated in the free concave margin of the falx cerebri. It is of small size, cylindric on section, and terminates in the straight sinus at the junction of the falx cerebri with the anterior margin of the tentorium cerelielli and at the posterior boundary of the superior occipital foramen. It receives veins from the falx cerebri, the median surface of the cerebral hemi- spheres, and the basilar surface of the frontal lobes. The straight sinus is formed by the union of the inferior longitudinal sinus with the veins of Galen. It is situated at the junction of the falx cerebri with the tentorium cerebelli, and terminates at the internal occipital protuberance, whence it is continued as the left lateral sinus. It is triangular on section and increases in .size as it passes backward. It receives veins from the tentorium cerebelli and the upper surface of the cerebellum (the superior cerebellar). Its direction is downward and backward. The occipital sinus is formed by the union of two small veins (marginal sinuses') which pass, around the lateral margins of the foramen magnum and com- municate with the sigmoid portion of the lateral sinus near the jugular foramen and with the posterior spinal veins. It passes along the attached margin of the falx cerebelli to the internal occipital protuberance, where it empties into the tor- cular Herophili. It may empty into one of the lateral sinuses or into the straight sinus. It receives veins from the tentorium cerebelli and cerebellum, communi- cating also with the vertebral veins and the anterior spinal plexus. The sinus alae parvae, or spheno-parietal sinus, one of the paired sinuses, occupies a groove on the inferior surface of the lesser wing of the sphenoid bone, and runs through the sphenoid fold of the dura mater. This fold is attached to the base of the lesser wing of the sphenoid bone, and is continuous with the dura mater at its attachment to the anterior clinoid process. It empties into the cavernous sinus, and often receives the fronto-sphenoid veins of the diploi us tributaries. '/'///; .I/A'.)//; A'.iAV-.N AM) !77'.7,N (>!' Till-: BRAIN. 589 The cavernous sinuses are situated along tlie sides of the body of the sphenoid bone, and extend from beneath the anterior clinoid proeesses to the apices of the petrous portions of the temporal bones. The outer wall of the sinus the most distinct contains the third and fourth nerves and the ophthalmic division of the fifth, while the inner wall contains the internal carotid artery, the sixth nerve, and the cavernous plexus of the sympathetic. "Tillaux alludes to some cases of aiieurysmul communication between the internal carotid artery and the sinus; the signs of such lesion are dilatation of the ophthalmic vein and a pul- satory swelling behind the internal angular process of the frontal bone " (Owen). Tin 1 endothelial lining membrane of the sinus prevents the blood from coming into contact with the nerves and artery. Practically speaking, the inner wall of the sinus does not exist as a distinct lamella, hut is formed by the structures pre- viously enumerated as being contained therein. Section of the sinus discloses numerous bands and spaces on its interior hence its name. The nerves which occupy the outer wall of the sinus observe I lie same order, both from above down- ward and from within outward, in which they have been mentioned. < )f the structures occupying the inner wall, the sixth nerve is the most external. The sinus receives the ophthalmic vein in front, and the sinus ahe parva> above the third nerve. It communicates with its fellow by means of the circular sinus, and divides posteriorly (at the apex of the petrous portion of the temporal bone) into the superior and inferior petrosal sinuses. It receives the middle cerebral veins and those from the basilar surface of the frontal lobe, communicating with the pterygoid plexus of veins by means of the Vesalian vein, which runs through the Yesalian foramen in the greater wing of the sphenoid hone. It also communicates with the internal jugular vein through the venous plexus surrounding the petrous portion of the internal carotid artery, and with the pterygoid and pharvngeal plexuses of veins by means of veins which run through the foramen ovale and the foramen lacerum medium. Infective material may reach the cavernous sinus from the scalp through the supra-orbital or frontal and ophthalmic veins, and through the fronto-sphenoid diploic vein and the sinus ake parvse ; from the orbit, through the ophthalmic vein ; and from the pterygo-maxillary region through the vein of Vesalius and emissary veins which pass through the foramina at the base of the skull. Relations of the cavernous sinus to the Gasserian ganglion. But one of the cavernous sinuses should be opened at this stage of the dissection, the opening of the other being deferred until the nerves which run in the walls of the sinus to enter the orbit have been traced. Upon opening the cavernous sinus it will be seen to occupy an interval between the endosteal and meningeal layers of the dura mater, as is the case with the other sinuses. In this interval Meckel's space, which is 590 SURGICAL ANATOMY. occupied liy the (ia.-serian ganglion, may also l>r demonstrated at this time'. The Comparatively hit i male relation existing l)et\veen the sinus and the ganglion should. therefore, be home in mind when attempting to remove the ganglion tor relief of trit'aeial neuralgia, otherwise the sinus might he injured: an accident of this kind, it is hardly necessary to say. might he serious. The circular 'sinus, through which the two cavernous sinuses communicate, surrounds the pituitary hodv. The anterior half is larger than the posterior, and in advanced life is larger than in early life. At times one-hall' is absent. It receives veins from the pituitary hody and the neighboring hone and dura mater. The superior and inferior petrosal sinuses arc the terminal divisions of the cavernous sinus. The superior /"/V- AND VESSELS or TIIK ni:.\i\. 593 Tin- auditory nerves, the eighth pair, leave tin- cranial cavity through the internal auditory incatuscs in company with the auditory arteries, the facial nerves, ami the pars intermedia. Reaching the hutlnm ul' the meatns each nervc> divides into two 1 mint-lies, the eorhlear and the vestilmlar, tor the supply of the cochlea, the veMibule, ami the .semicircular canals. The glosso-pharyngeal nerves, the ninth pair; the pnetunogastric (vagus), the tenth pair: and the spinal accessory, the eleventh pair, leave the cranial cavity by way of the jugular or posterior lacerated foramen, passing through its midtlle compartment. The glosso-pharyngeal nerves have a separate sheath of dura mater and arachnoid, and lie in front of tht> pneumogastric and spinal accessory nerves. The last-mentioned two have a sheath of dura mater common to hoth, hut they have separate sheaths of arachnoid.* The spinal accessory nerve is made up of t-wu pails: a smaller or accessor; portion (accessory to the pneuino- gastric nerve), which runs with the pnenmogastric. and a spinal, which arises from the spinal cord, and is hy far the larger portion. The latter enters the cranial cavity through the foramen magnum and joins the accessory portion shortly after the latter emerges from the medulla. The hypo-glossal nerves, the twelfth pair, leave the cranial cavity through the anterior condyloid foramina. The internal carotid artery. When the cavernous sinus has been laid open and the nerves within its wall exposed, carefully examine the internal carotid artery running in the inner wall of the sinus hefore disturbing the dura mater further. After its exit from the carotid canal, the curves which the artery makes in reaching the brain can now be seen to the best advantage. Having emerged from the carotid canal the artery turns upward, passing toward the posterior clinoid process. It next runs forward through the inner wall of the sinus to reach the inner side of the anterior clinoid process, where it again turns upward and pierces the dura mater on the inner aspect of the anterior clinoid process; just before piercing the dura mater it gives off the ophthalmic branch. The cranial or terminal portion thus makes two bends, which give it the shape of the letter S. Running along with the artery and external to it is the abducent (sixth) nerve. The lining membrane of the sinus alone separates both the artery and the nerve from the interior of the sinus. Within the walls of the sinus the artery gives off branches known as the arteria? receptaculi, which supply the walls of the sinus, the pituitary body, the Gasscrian ganglion, and the dura mater (through the anterior meningeal). It is surrounded by filaments of the sympathetic nerve which form two plexuses, the carotid on the outer and the cavernous on the inner side of the artery. The former plexus communicates with the abducent nerve and the Gasserian and Meckel's ganglia; the latter communicates with the oculo- 38 .V.M SURGICAL AXATOMY. motor, pathetic, and ophthalmic nerves, and Furnishes the- sympathetic root to the ophthalmic or lenticular ganglion. DISSKCTION. The dura mater should now lie dissected From the sides and base of the skull ; it will be Found closely adherent to the latter, requiring care in its removal in order to avoid injuring the Following structures: The ( lasserian ganglion, the superior and interior maxillary nerves, which are branches From tin- ganglion, the In rye superficial petrosal. the external supcriicinl petrosal when present, and the motor root of the trifacial nerve. The last and the large superficial petrosal nerve run beneath the ganglion. The Gasserian ganglion occupies a depression on the superior surface of the petrous portion of the temporal bone near the apex, and rests to a slight extent on the cartilage tilling the middle lacerated foramen. It holds an intimate relation, therefore, to both the internal carotid artery and the cavernous sinus. It is cres- ceiitic in outline, its concavity being directed backward and its convexity forward and outward, and it measures about one-half of an inch in width. Its upper and lower surfaces are slightly convex. It occupies an interval between the endosteai and meningeal layers of the dura mater (Mirl:i-l'x */w/ n-SSELS OF THE IlllMX. :,'.).-, the line of tin- original incision, preferably with an instrument specially con- structed for this purpose. Ciuvniust l>c taken to avoid injuring tlic membrane- of the brain. An elevator is introduced beneath the hone after it has been cut through along the whole line of the incision, and the entire flap is forced outward and downward. The bone will fracture between the ends of the oval incision a little above the line of the zygomatic arch. The bone and soft structures should be reflected as one flap in thus exposing the dura mater of the brain. When the middle meningeal artery lies in a canal in the temporal and parietal bones, it may be torn in forcing the flap downward. This necessitates tying the vessel or plugging the canal for the vessel with gauxe, as the bleeding would be severe. The dura mater is separated from the floor of the middle cranial fosaa, and when the brain is lifted upward, the superior and inferior maxillary divisions of the fifth or trifacial nerve will be exposed. As much as ]x>ssible of both nerves is then excised, and the distal ends pushed through their respective foramina of exit. The operation is completed by repositing the flap of bone, sutur- ing the soft parts, and dressing the wound. Removal of the Gasserian ganglion. In removing the Gasserian ganglion one of two routes can be selected, either through the side of the skull or through its base : the latter method was first practised by Mr. Rose. In the former method, by far the most preferable, an osteo-plastic resection of the side of the skull is made, similar to that in the previous operation. The flap of bone includes part of the frontal, greater wing of the sphenoid, parietal, and the squamous portion of the temporal bone. After the superior and inferior maxillary nerves are exposed, they should be traced backward to the Gasserian ganglion ; this is lodged in a depression near the apex of the petrous portion of the temporal bone, in a space (Meckel's) situated between the two layers of the dura mater. The outer layer of the dura mater should be incised, and the ganglion removed. The inferior and superior maxillary divisions of the trifacial nerve arc then resected up to their point of exit from the skull, and the distal ends pushed through their respective foramina. The inferior maxillary nerve leaves the skull through the foramen ovale ; the superior maxillary nerve through the fora- men rotundum. The osteo-plastic flap is then replaced and the wound closed. The final steps of this and the succeeding operation will be greatly facilitated by the use of an electric headlight attached to a head-band. In the second method the first step consists of dissecting up a flap of skin, superficial and deep fascia from the side of the face, and exposing the zygoma, taking care not to wound the parotid duct. The zygoma should be sawed through at each end and turned down, along with the masseter muscle. Next divide the coronoid process of the inferior maxilla and turn it upward with .V.ii; SURGICAL .\\AToMy. the temporal muscle; this exposes the internal maxillary artery and ptcrygoid muscles. The internal maxillary artery should he tied at two points and divided. The external ptcrygoid muscle should then he carefully detached from its origin, thus exposing the inferior maxillary nerve as it emerges from the foramen ovale, which is the point at the hase of the skull to he attacked with the trephine. If the inferior maxillary nerve has not heeii removed hy a previous operation, it acts as an important guide in locating the foramen. The eminentia articiilaris and the root of the pterygoid process are additional guides. the foramen being usually just in front of a transverse line drawn through the eminence, and immediately hehind the root of the external pterygoid plate. When the foramen has heen clearly exposed, apply a small trephine, one-half of an inch in diameter, to the hase of the skull and remove a hntton of hone which includes the margin of the foramen. The proximity of the fora- men to the carotid canal renders this step a very important one. The disc of hone having heen removed, the exposed dura mater, which bulge- more or le-s into the trephine hole, should he opened and the inferior maxillary nerve, if not already exposed, sought. When found, it is traced to the (lasserian ganglion, which is then removed piecemeal. The operation is completed hy replacing the tissues in as nearly the normal position as possible ; the zygoma and the hone on each side of it are drilled and sutured, drainage is introduced, and the wound dosed. The hutton of bone is not replaced. Extreme care should he exercised throughout this operation, which is one of great magnitude. The nutrition of the eyeball may he so seriously atlected as to result in its destruction. DISSKCTIO.X. To continue the dissection, divide the larger or sensory root of the trifacial nerve, lift the Gasserian ganglion, and displace it forward and down- ward SD as to better expose the smaller motor root and the large superlicial petrosal nerve, both of which lie heiieath the ganglion. The motor root of the trifacial nerve can he traced to the foramen ovale, where, with the inferior maxillary nerve, it makes its exit from the skull. The large superficial petrosal nerve arises from the geniculate ganglion of the facial nerve, and will be seen emerging from the hiatus Fallopii. Thence it runs in a small groove on the side of the superior surface of the petrous portion of the temporal hone to reach the cartilage which fills the middle lacerated foramen. It pierces the cartilage and is joined by the great deep petrosal nerve from the carotid plexus of the sympathetic, thus forming the Vidian nerve. The small superficial petrosal nerve arises from the facial nerve, emerges from the facial canal by way of a small foramen situated external to the hiatus Fallopii, passes to the foramen ovale, and joins the otic ganglion. Occasionally it passes through a small- foramen situated between the foramina ovale and spinosum. '////: .v AM//; A', i. \7'>' A.\D ]V-V-;/.N or TJII-: iin.i/x. 597 The external superficial petrosal nerve leaves the facial nerve ami canal by way of a small foramen placed external to that i'<>r the small superticial petrosal nerve, on its way to join the plexus of the sympathetic upon the middle meningcal artery. This nerve is seldom found in the dissection of the interior of the Imse of the cranium, for in lifting up the endosteal layer of the dura mater the petrosal nerves are very apt to he severed unless the utmost care is observed. The Meningeal Arteries the {interior, the middle, the small, and the posterior nieiiingeal run between the skull and the dura mater, and are apt to lie destroyed, or at least cut. when removing the dura mater; notwithstanding this they can he traced by the Amoves in the hones which they occupy. The greater part of the anterior branch of the middle and the terminal part of the posterior nieningeal arteries have been observed when removing the culvaria. The middle meningeal artery. The largest and most important of the meiiingcal arteries is the middle. As seen when dissecting the pterygo-max :liary region, both this and the small meningeal are branches of the internal maxillary artery. The middle meningeal artery runs between the two roots of the auriculo- temporal nerve and enter- the cranial cavity by way of the fora men spiimsum; it occupies a groove in the greater wing of the sphenoid bone, and almost immediately divides into two branches, the anterior and the posterior. Small branches of the middle meningeal artery pierce the cranial bones and anastomose with the vessels of the scalp. The iinfi-rinr /n'l/nr/i runs through a groove across the great wing of the sphe- noid, and continues into another groove in the anterior inferior angle of the parietal bone. The commencement of this latter groove for a distance of one-fourth to one- half of an inch is often bridged over by a thin plate of bone, and is thus converted into a canal. The vessel continues along the groove near the anterior border of the parietal bone, runs almost parallel with the coronal suture to within a short distance of the superior longitudinal sinus, and gives off brandies which run upward to the vertex and backward toward the occipital bone. The sinus ahe parv;e or spheiio-parietal venous sinus at times accompanies the artery- for a part of its course, and may consequently be injured in fracture or during the manipulations of the surgeon. The posterior In-nm-li. the smaller of the two, crosses the squamous portion of the temporal bone along the line of junction of the squamons with the petrous por- tion, and then upon the posterior inferior angle of the parietal bone, where it divides into its branches. Extra-dural hemorrhage. From the relation which the anterior branch of the middle meningeal artery holds to the anterior inferior angle of the parietal bone, it follows that fracture of this part of the skull is apt to result 598 SUR<:H'.\L AX ATOMY. in hemorrhage, which would he located between the hone and the dura mater. The vessel may lie injured either hy sharp bony spieula or by (lie sudden alteration in shape to which the skull is subjected in cases of severe head injury. It has already heen noted that the dura mater is loosely attached to the vault of the cranium; this accounts for the six.e of the large extra-dnral blood-clots oreasionally seen. From the relation of this branch to the motor area of the brain it can readily be understood why the symptoms eonse,|uenf upon the pressure of an extra-dnral clot are largely, if not altogether, motor. The-e eases constitute an especially favorable class for trephining, which should be done as soon as the diagnosis is made, or as early as possible. If upon the removal of the clot the bleeding has not ceased, the vessel should be tied. This may ssitate enlarging the original trephine opening in order to expose the bleeding points. The author lias found it necessary to tie both the anterior and the posterior branch. It occasionally happens that the injury to the middle meningeal artery occurs on the opposite side to that upon which the external !< sioii exists. Point for trephining. The point of election for applying the trephine in a suspected case of extra-dural hemorrhage, meningeal in origin, is at a point one and one-half inches behind and one inch above the external angular process of the frontal bone. When a simple or a compound depressed fracture is associated with the hemorrhage, the trephine should be applied near the fracture. To reach the posterior branch the trephine should be applied immediately below the parietal eminence, and on the same horizontal level as in the preceding operation. The opening can subsequently be enlarged in a downward or backward direction and the vessel thus brought into view. Branches of the middle meningeal artery. The middle meningeal artery gives off branches within the cranial cavity to the (lasserian ganglion: a petrosal branch, which enters the hiatus Fallopii to supply the facial nerve and anasto- moses with the stylo-mastoid branch of the posterior auricular artery; a lacrymal branch which enters the orbit by way of the sphenoid fissure, or by a separate canal in the greater wing of the sphenoid bone, and anastomoses with the oph- thalmic artery; a branch to the tensor tympani muscle; and branches which have the cranial cavity through foramina in the great wing of the sphenoid bone to anastomose in the temporal fossa with the deep temporal arteries. It is accompanied by two veins which empty into the internal maxillary vein. The anterior meningeal arteries are branches of the ethmoid arteries ; they supply the dura mater of the anterior cranial fossa in the region of the median line. One of the arteria receptaculii, derived from the cavernous portion of the internal carotid artery, supplies the dura mater of the middle cranial fossa. It 7V//-: MEMBRANES AND IV-7-.7>' OF THE J!1!AL\. anastomoses with the middle meningeal artery, an of inferior coronary a.. 507 labial a.. 5117 or long thoracic a., 85 prol'unda ;i., 114 of infra-orbital a.. 5 In of internal mammary a.. s."> of interosscous a., palmar, 180 posterior. 208 recurrent a., -Mil) of lateralis nasi a., .",0- of mammary lymphatics, 57 of mental a.. 540 of occipital a., 470 of palmar interosseous a.. 1-0 of perforating a., IbO, 173, 177 superior, of hand, 180 of posterior auricular a., 470 circumllex a.. *5. si; interosseous a., 2os -eapular a., -li. 384, 385 temporal a., 170 ulnar recurrent a., 147 of princeps ccrvicis a.. 402 of profunda ccrvicis a., 403 of radial recurrent a., 144, 180 of recurrent carpal a., 180 of scapular a.. s(j posterior, 86, ::-'!, 385 of subscapular a., 385 of superior coronary a , 507 perforating a. of hand, 180 prot'unda a.. 113, 192 thoracic a . S5 ulnar recurrent a., 147 of supra-orbital a., 4liil of supra-scapular a., sr>, 384, 385 of transverse facial a., 508 Anastomotica magnaa., 114, 110, 111, 115, 118, 128. 145 anastomosis, 1 14 branches, 114 Anatomic neck of humerus, fracture, 273 displacement in, 273 structures in- volved, '37:5 of scapula, fracture, 270 snuff-box, 32 branches of radial a. in, 32 contents, 32 incision to expose ra- dial a. in, 337 radial a. in, 339 Anatomy, long bones, 256 structural, of arteries, 298 Ancouens m., 202, 184, 194, 200 action, 202 blood supply. 202 insertion, 202 nerve supply, 202 origin, 202 relations, 202 Ariel's method of treating ancii- rysin, 2! 17 Anesthesia, temporal a. in, 170 Anenrvsm. artci io-venous. si ciisoid, 470, 463 general considerations. -Jill method of treating, Auel's, 297 Antyllns'. 2!7, 295 Brasdor s. 21)7, 295 coagulating mate- rial. -is foreign body, 2!'s ga 1 v a no-puncture, ~ 29s Hunter's. 21)7. 295 manipulation, 2!)8 pressure. 2117 War drop's. 2!i7. 295 treatment of. 294 varicose. :!01). 295 \neurvsmal varix. 30S, 295 Angle, acromial, 351, 362, 43 at elbow, 17, 21 of sca]>ula. inferior. 3li2 Angular a., 502,508. 472, 477, 504 anastomosis. 508 rein, 509 Ankvlosis, false, 215 of elbow after excision. 2(i:! Annular ligament of wrist, anter- ior, 121). 157. 2::o. 159, 173 compartments, 157, 167 relations, 157 posterior. 12!), 196, 194. 206 compartments. 1(17 Anomalies of inammarv glands. 63 Antecubital fossa, 38 Anthelix. J'/Wc Antihelix. Antihelix, 524. 525 fossa, 524. 525 Antitragicus in., 529, 527 Antitragus, 524, 525 Antvllus' method of treating aneurysm, 2!)~. 295 Aponeurosis, bicipital, 110, 110, 115, 128, 131, 135, 140, 141 of latissimus dorsi m.. 373. 396 of occipito-frontalis m., 479, 463, 491 snbscapular, 387 vertebral, 394 Appendages of eye, 512 Arachnoid membrane of brain, 573 of cord, 431, 429 Arch, anterior carpal, 173 bony, of shoulder. 1 -i carpal, anterior. 173 hemorrhage from. 180 posterior, 210, 194 branches, 210 coraco-acromial, 222 Arch, deep palmar. 171), 145, 173, 177 branches, 1-u course. ]s(l line. 122, 176, 300 relations, 180 wounds. ls() palmar, dec]). 17!). 145, 173, 177 branches, Isn course. ISO line. 122, 176. 300 relation^. 1-0 wounds, 180 superficial, 147, 1(11. 145, 159, 177 branches. 161 course, lo'l formation, 161 line, 122, 176, 300 relations. 161 posterior carpal. 210, 194 branches, 210 prccarpal, 148 superficial palmar. 147. 101, 145, 159. 177 branches, llil course, llil formation. 161 line. 122, 176, 300 relations, 1(!1 supra-orbital. 457 /ygomatic, 460 Areas of spinal cord, motor, 445 rellex, 445 sensory, 445 Areola of nipple, 54, 55 Areolar tissue of axilla, 95 of eyelids. 516 of scalp, 4-o Arm, amputation of, 293 structures involved, 293 arteries, superficial, 103 back of, dissection of, 1-s fascia, deep. Iss muscles of, 185 collateral circulation, dia- gram, 324 comparative lengths of, 18 edema, 81 fascia, deep. 100 front of, 96 cutaneous nerves, 96 dissection. 96 fascia, deep, 107 lymphatic glands. 104, 105 vessels, 104, 105 muscles, 104 veins, superficial, 100 intermnscnlar septa, 107, 110 landmarks, 21, 24, 25 measurements, 47 movements of, in affections of the breast, 58 nerves, 120 osteo-fascial compartments. 108 INDEX. 003 Ami, osteo-Iasrial ciilll|iill-| lllcllts. ((intents, in* section of, transverse, 290, 291 superficial arteries, UK! fascia of front, !)(> veins. 103 \as:i alierrantia, 114 Arm-pit, the, 71. I'/ili Axilla. Arnold's ganglion. .">.Vi Aiteria se|itnm narinm. .",(17 Arteria- receptacnli. .">:):; Arterial blood ill lacial vein, 511 Arteries, anastomoses, around scapula. 84, 385 anatomy, .!!)-< divided in excision ol' breast, libation, gangrene following, 304 general considerations, 303 hemorrhage followiii", 304 of back, 367 of ear, 529 of face, 4(>0, 472, 477, 504 of forearm, 145 of hand, 145, 177 lines. 35 of back, 206 of palm, 176 of scalp, 152, 4(i!l, 472, 477, 504 of septum of nose. 507. 472, 477. 504 hemorrhage from, 507 of spinal cord, 44 1 of upper extremity, ligation, 394 lines, 122, 300 sheath. 298 .superficial, of arm, 103 Artei io-venons aiieurysin, 81 Artery, acromial branch of acro- mio-thoraeic, 48, 85 anastomosis. 85 acromio-thoracic, 85, 70, 71, 76 acromial branch, 48, 85 branches, 85 descending branch, 48, 85 thoracic branch, 48, 85 anastomosis. -5 alar thoracic, 85. 76 alveolar, 548, 542 anastomotica magna, 114, 110, 111, 115, 118, 128, 145 anastomosis. 114 branches, 114 angular. 502, 508, 472, 477, 504 anastomosis, 508 anterior auricular, 472, 477, 484, 504 carpal, radial, 144, 145, 135. 173, 177 Artery, anterior carpal, ulnar. 1 K 135, 340, 141, 145, 173, 177 anastomosis, 1 H circumflex, S9, 76, 77, 111, 118 aiia.-tomosis. -II branches. -9 ill excision of shoul- der-joint, -li deep temporal, 547, 542, 546, 550 dental, 540 intercostal o f internal mammary. I* interosseous, 117. 140, 141, 145, 177, 203 mcningcai. 5ii- spinal, 441, 429, 433 superior dental, 548, 549 temporal. 470. 467, 472, 477, 504 anastomosis, 470 ulnar recurrent, 147, 111, 140, 141, 145 anastomosis, 1 17 articular branch of posterior interosseous, 208 auricular, anterior, 470, 472, 477,484, 504 anastomosis, 470 deep, 547, 546 posterior. 470. 467, 472, 477, 484, 504, 542 anastomosis, 470 axillary, 81, 62, 72, 76, 77, 111 branches of iirst portion, 82 of second portion, 85 of third ]Hirtion. M! course, 27, 81 digital compression, 82 divisions, 82 first portion, 82 branches, 82 incision for libation. 301 ligation, 8:>, :',OI collateral c i r e u 1 a- tioii after, 306 line for, 45 operation to expose, 316, 317 pressure upon, "81 relations, 82, 89, 305, 316 second portion, 85 branches, 85 third portion, 85 branches, 86 bicipital branch of anterior circumflex, 89 brachial, 108, 110, 111. 115, 118, 128, 131, 135, 140. 141, 145 branches. 113, 111 course, 28 Arterv, bracial, incision for liga- tiou, 301 ligation, 307 collateral circula- tion alter. 3o>. :;i 111 structures involved, 307 line, 108, 307, 122, 300 operation to expose, 316, 317, 319 relations, 108, 307, 316, 317 at elbow. 328, 329 vena; comites, 1 13 buccal, 548, 542, 546, 559 carotid, common, line for, 487 external, 542. 546,550 internal, 5!)3, 579 course. 593 carpal, anterior, radial. 144, 135, 145, 173, 177 anastomosis, 148 ulnar, 148. 135, 140, 141, 145, 173, 177 posterior, radial, 2*1, 145, 177, 200. 206 ulnar. 211. 140, 141, 177, 200, 206 recurrent. 180, 145. 173, 177 anastomosis. 1-0 course, 180 circumflex, 184, 185 anterior, 89, 76, 77, 111, 118 anastomosis. -'.".. -II branches, 89 in excision of shoul- der-joint. 89 posterior, 85, 111, 184, 185 anastomosis, 85, 86 incision lor, 40 ligation. 306 structures in- volved, 306 operation to expose, 341 collateral digital, 162, 140, 159. 173, 177 line. 176 common carotid. 487 line, 487 interosseous, 147. 140, 141, 145, 203 coronary, inferior, of lip, 5o7, 472, 477, 504 anastomosis, 507 course, 507 superior, of lip, 507.472, 477, 504 anastomosis, 507 deep auricular, 547, 546 temporal, anterior, 542 posterior, 547, 542, 546 604 IXDI-:\. \ilery, dental, anterior, 546 superior. .M-i. 559 inferior, 517. 542, 546, 550, 559 middle superior, 559 |pi)sterior, it-lS, 546 desci-ndinf: branch of acro- mio-thoracic. H palatine. 54*. 546 digital, of hand, 161, 140, 141, 145, 156, 159, 173, 177 collateral. 102, 140, 159, 173, 177 line, 176 dorsal, 211 anastomosis, 211 Hue, 176 of bifurcation, 37 relations. Hi'J dorsal interosseous, 145. 177, 206 dor-alis indicia. 211, 145, 177, 200, 206 anastomosis, 211 pollicis, 311, 145, 177, 200, 206 scapula;, 86, 384. 76, 77, 84, 111, 185, 343, 385 anastomosis, 8(i, .'I- 1, 385 external earotid. 542, 546, 550 mammary, deep, 58, 85 superficial, 58 ptervsioid, 548, 546 facial. 472, 477, 484, 485, 504 anastomosis, 512 brandies, 5(17 course. 502 line, 487 relations, 502 transverse, 472, 477. 484, 504, 542 anastomosis. 508 frontal, 470, 467, 472, 477, 484, 504 anastomosis. 470 Rinjiival, 546, 559 luimeral branch of acromio- thoracic, 85 anastomosis, 85 incisive, 547, 546 inferior coronary, of lip, 507. 472,477,504 anastomosis, 507 course, 507 dental, 547, 542, 546, 550, 559 labial, 507, 472, 477, 504 anastomosis, 507 profnnda, of arm, 113, 110, 111, 115, 118, 128, 145 anastomosis, 114 thoracic, 85 anastomosis, 85 Artery, infra-orbital, 54o, 5 4.-. 484, 542, 546, 550, 559 anastomosis. 5 HI intercostal, anterior, of inter- nal mammary, 48 internal carotid. 5!i:!, 579 course, 593 mammary. --5 branches, 48 maxillary, 543, 544. 484, 485, 542, 546, 550, 559 branches, 547 divisions. 547 ptervgoid, 548, 546 interosseons, anterior, 147, 140, 141, 145, 177, 203 common, 147. 140, 141, 145, 203 dorsal, 145, 177, 206 lirst, 211 of hand, 37. 140, 141, 159, 173 line, 176 palmar, 180, 145, 177 anastomosis, l-o course, 180 posterior, 208, 140, 141, 145, 194, 200, 203 anastomosis. 208 branches, 208 relation. 208 recurrent, 208, 111, 145, 200 second, 210 third. 210 labial, interior, 546, 472, 477, 504, 546 anastomosis, 507 lateral nasal. 477 spinal, 44 1 lateralis nasi, 508 anastomosis, 508 long thoracic, 53, 58, 76 mammary, deep external, 58. S5 external, deep, 58, 85 internal, anastomosis, >."> masseteric. 51-*, 485, 542, 546 mastoid. 403 maxillary, internal, 543, 514, 547, 484, 485, 542, 546, 550, 559 anastomosis, 85 median, of forearm, 148, 140 of spinal cord, 444 meniugeal, anterior, 598 middle, 456, 547, 597. 546, 550, 554, 559, 573, 578, 579 branches. 597, 598 wound, 598 posterior, 599 small, 547. 599, 546, 550, 559 mental, 540, 547, 484, 546, 559 Artery, mental, anastomosis. 510 metacarpal. 211. 145, 200, 206 middle meningeal. 456 550. 5!I7: 546, 554, 559, 573, 578, 579 branches, 5!I7, 5ii- \\onnd, 598 superior dental, 559 temporal. 472, 504, 477, 484 mylo-hyoid, 547, 546, 550, 559' nasal, 546 lateral, 477 naso-palatine, 5 I- mitrient, of humerus, 114, 111 occipital. 402, 470. 406, 467, 472, 477. 504 anastomosis. 470 branches, 402 ophthalmic, 579 orbital, 472, 504, 546 palatine, descending, 54*, 546 palmar interosseons, 1-n, 145, 177 anastomosis, 180 course, l-o pnlpehral, 546 perforating branches of in- ternal mammary, 4s. 49 of interosseons 211 of hand, 180, 173, 177 anastomosis. Iso course, 180 posterior articular branch of the superior profnnda, 113 auricular. 170. 467, 472, 477, 484, 504, 542 anastomosis. 470 carpal, radial. 211. 145, 177, 200, 206 ulnar, 211. 14O, 141, 177, 200, 206 circumflex. s.">. 111, 184, 185 anastomosis, 85. S6 incision, 40 ligation. 30ii structures irj- yolved, 306 operation to expose. 341 deep temporal, 547. 542, 546 dental, 548, 546 interosseous, 208, 140, 141, 145, 194, 200, 203 anastomosis. 208 branches, 208 relations, 208 meninjieal. 599 scapular, 384. 84, 385 anastomosis. 384, 86, 385 L\DI:\. 605 Artery, posterior scapular, branches. :;- I relations, 384 spinal, 444 temporal, 47(1. 467,472, 477. 504 anastomosis. 470 ulnar recurrent, 147, 111, 140, 141, 200 anastomosis, 117 prineeps cervieis. 4(1:2, 406 anastomosis, 102 branches, 402 pollicis. 180. 140, 141, 145, 159, 173, 177 branches, 180 coinse. 1st) line, 176 relalions, 1*0 prolunda eervicis, 403, 406 anastomosis, 403 inferior. 113, 111, 115, 118. 128, 145 anastomosis, 114 superior. 113, 192, 110, 111, 145, 184, 194, 200 anastomosis, 113, 192 branches, 113. 192 relations, 192 pterygoid, 542 external, 548, 546 internal, 548, 546 pterygo-palatine, 548. 546 radial, 143, 210, 110, 111, 128, 131, 135, 140, 141, 145, 159, 173, 177, 194, 200, 206 branches, 144, 210 ill anatomic snuff- box, 32 course, 31 in anatomic snuff-box, 339 line of incision, 337 incision for lighting, 301 ligation, 310 collateral circulation after. :!11 structures involved, 310 line. 143,309, 122, 176, 300 pulsation, 31 recurrent, 144, 131, 145, 345, 347 anastomosis, 144 relations. 143, 210, 328, 331, 333 to bicipital aponeu- rosis, 119 vena comes, 128 radialis indicia, 180, 140, 141, 145, 159, 173, 177 course, 180 line, 176 recurrent, anterior ulnar, 147, 111, 140, 141, 145 Artery, recurrent, anterior ulnnr, anastomosis, 147 carpal, ISO, 145, 173. 177 anastomosis. 180 course, ISO interossecms, 20-\ 111, 145, 200 posterioriilnar, 147, 111, 140. 141, 200 radial, 144, 131, 145, 345, 347 anastomosis, 11 1 ulnar, anterior, 147, 111, 140, 141, 145 posterior, 147, 111, 140, 141, 200 scapular, posterior, 384, 84, 385 anast otnosis, 384, 86, 385 branches, :!-'[ relations, 384 small meningeal, 547, "'ii'i. 550, 559 spheno-palatine, 54.-% 546 spinal, 127 anterior, 444, 429, 433 lateral, 444. ]>sterior, 444 subclavian, relations of, to axillary ple.xns, s!l snbinental, 546 subscapnlar, 86, 76, 77, 84, 111, 385 anastomosis, 86, 385 branches, si; incision for ligation, 301 ligation, 30!) structures involved, 306 line, 86 operation to expose, 343 superficial, of arm, 103 of forearm, 129 temporal, 484, 485, 504, 542, 546, 550 superficialis vohe, 32, 144, 131, 135, 145, 159, 173, 177 line, 176 superior corouarv. of lip, 507, 472, 477, 504 an as tomosis. 507 profunda, 113, 192, 110, 111, 145, 184, 194, 200 anastomosis, 113,192 branches, 113, 192 relations. 192 thoracic, 82, 71, 76 anastomosis, 85 supra-orbital. 4(), 467, 472, 477, 484, 504 anastomosis, 469 supra-scapular. 384, 84, 385 anastomosis, 85, 384, 385 relations. 384 temporal, 470, 485 Artery, temporal, anterior, 470, 467, 472, 477, 504 anastomosis. 470 deep. 547. 542, 546, 550 in anesthesia, 470 middle, 472, 477, 484, 504 posleiior. 170. 467, 477, 504, 550 anastomosis. 470 deep, 547,542, 546 superficial. 484, 485, 504. 542, 546, 550 thoracic branch of acromio- thoracic, 48, 85 anastomosis. S5 inferior or long, 85 anastomosis, >."> superior, 82, 76 anastomosis, .-."> transverse facial, fills, 472, 477, 484, 504, 542 anastomosis, 5(is tvmpanic, 547. 546, 550 ulnar, 144, 111, 131, 135, 140, 141, 145, 159, 173, 177 branches, 147 course, 31 guide for ligation, 134 incision for ligation, 301 ligation. 31 1 collateral circulation after, 311 structures involved, 311 line, 144, 122,176,300 recurrent, anterior, 147, 111, 140, 141, 145 anastomosis, 147 posterior, 147, 111, 140, 141, 200 anastoino> i s, 147 relations, 147. 328, 335 vertebral, 408, 406 Vidian, 548, 546 Arthritis, rheumatic, 215 tubercular, 215 Articular a., of posterior interos- seons, 208 posterior, of superior pro- funda, 113 branch of median n., 148 of posterior iuterosseous n., 209 of ulnar n., 151 cartilage, 212 Articulation, acromio-clavicular, 218, 219. Vide Scapnlo- clavicnlar. atlanto-axoid, 419 central, 419, 421 lateral, 419 ligaments, 419 movements, 420 606 IX I) EX. Articulation, carpal. '.':!- blood supply, 242 formation, 2.'!-^ ligaments, 23* movements. 2 12 nerve supply, 242 carpo-mctaearpal, 231, 235 tirst set, 212 blood s up pi v, -.' I.") formation, 242 ligaments, 2 12 movements 245 nerve s u p p I v, :.' 15 second set, 245 lilood sup pi v, 2 15 formation, 215 ligaments, 245 movements, 245 nerve supply, 245 elbow, 17, 224, 225 amputation. 2" blood supply, 22* bursa, 228 excision, 262 formation, 224 ligaments, 227 movements, 228 nerve supply, 228 relations, 228 syuovial membrane, 228 synovitis, 228 inferior radio-uluar, 17, 233, 230, 231, 235 blood supply, 21! 1 formation, 233 ligaments, 233 movements, 233 nerve supply, 2:! 1 intercarpal, 238, 23i, 235 intenuetacarpal, 245 blood supply, 246 formation, 245 ligaments, 245 nerve supply, 246 iiiterphalangeal, 247 blood supply, 217 ligaments, 217. 244 movements. 2 17 nerve supply, 2 17 position, 37 .-ynovial membrane, 247 lateral atlauto-axoicl, 1111 medio-earpal. 211 blood supply, 212 formation. 241 ligaments, 241 movements, 242 nerve supply, 242 synovia! membrane. 212 metacarpo-phalaugeal, 246 blood supply, 246 formation, 246 ligaments, 24fi movements, 246 nerve supply, 246 synovial membrane, 246 oecipito-atlantal, 423 blood supply, 424 ligaments, 423 Articulation, oecipito-atlantal, movements. I 1 . 1 :! nerve supply, 424 occipito-axoid, ligaments, 420 radio-carpal, 234, 231, 235, 239 blood supply. 2:;- disarticulation, 284 dislocation, 255 excision. 263 formation, 234 ligaments. 231 movements. _>:!-< nerve sup|ily. 211* radio-ulnar, inferior, 233, 230, 231, 235 blood supply. 21! I formation. 2:;:! ligaments. 233 movements. 233 nerve supply, 234 superior, 17, 233 blood supply, 233 formation, 233 ligaments, 233 movements. 233 nerve supply, 233 scapulo clavicular. 221, 218, 219 blood supply. 222 formation, 221 ligaments, 221 movements, 222 nerve supply, 222 relations, 222 scapulo-bumeral, 218. Tide Articulation, Shoulder, shoulder, 222 abscess, 379 amputation. 293 blood supplv. 224 bursa, 223 dislocation. 24*, 249 excision, 261 formation, 222 ligaments. 223 movements, 224 nerve supply, 224 relations, 221 synovial membrane, 223 synovitis, 223 stei no-clavicular, 215, 214 blood supply, 216 formation, 215 ligaments, 216 movements. 221 nerve supply, 221 superior radio-ulnar, 17. 233 blood supply, 233 formation, 233 ligaments, 233 movements, 233 nerve supply, 233 wrist. Vide Articulation, Kadio-carpal. Articulations, 212 . divisions, 215 of upper extremity, 215 Aspiration of pleural sac, 351 Asterion, the, 455 Athelia, 63 Atlanto-axoid joint. 419 central, 419, 421 Atlanto-axoid joint, lateral, 419 movements. Tin ligament. 415 anterior, 419, 417 capsular, 417 posterior, II!) superficial, 419 svnovial membrane. 417 Atrophy ofdcltoid m . 27. 251 . 379 Attachments of dura mater of brain, 575 of muscles of scapula. 393 Attolens aurem in., 469, 491 action. 4iili insertion, liili nerve supply. 4(19 origin, 469 Attraheus aurem in., 469, 491 action. Kill insertion, 469 nerve supply, 469 origin, 469 Auditory n., 593 Auricle,' the, 524, 525 landmarks. 524 Auricular a., anterior, 470. 472, 477, 484, 504 anastomosis. 470 deep, 547, 546 posterior, 470, 467, 472, 477, 484, 504, 542 anastomosis, 470 lymphatic- gland.-, 566 \c-ssels, 479 nerve, 530 anterior, 552 great. 473 posterior, 476 region, dissection. 521 vein, posterior, 509 Auriculo-tempond n., 476, 552, 473, 477, 484, 550, 542, 554, 559 divisions, 552 Auscultation of chest, 352 Axilla, the, 27, 74, 76, 77 abscess, 27. 79, 95 contents, 80 depth, 79 dissection, from before back- ward, 76 from below upward, 95, 77 folds, 27, 24 glands, 27 landmarks, 27 suspensory ligament, 6-S walls, 79 Axillary a., 81, 62, 72, 76, 77, 111 branches. first portion. -2 second portion, 85 third portion, 86 course. 27. M digital compression, 82 divisions, >2 first portion, s'2 branches, 82 incision forligation, 301 ligation, 82, 304 collateral circula- tion after, 306 JM)EX. 607 Axillary a., line. 45 operation to expose, 316. 317 pressure upon. -1 relations. --'. 89, 305, 316 srrond portion. -"> l)ranehes, 85 third portion, .-5 bninehes, 86 fascia, li*, 71, 59 diagram, 62 lymphatic Clauds, 92 in ea r i- i n o in a of breast, 92 nerve plexus, 89, 76, 87 brandies. 00 formation, 89 incision to expose, 301 motor points, 40 pressure upon. .-!( relations, t o axil- lary a., 89 to subelaviau a., 89 stretching, 38, 311, :;i I st ruptures i 11 - volved, 31-2 vein, HO, 62, 71, 76, 77 pressure upon. *1 relations, 316, 317 wound, 57, 80 vessels, 80 sheatli. -0 wall, anterior, (i 1 A.xo-appendicular m., 411 B. Back, arteries. :!(i7 cutaneous nerves, 371, 369 dissection, 307 fascia, deep, 371 landmarks, 353 muscles. 373, 396 deep, 397 nerves, 3(>7. -109 of arm. 1*-* of forearm, 195 of neck, 351 of shoulder, 351 of trunk, 351 surface markings, 353 Ball of thumb, 32 Base of skull, fracture, 55(i Basilar plexus. 578 Basilic v., 104, 100, 110, 115. 118, 128 median. 103, 100, 110. 128 infusion into, 104 Bell, external respiratorv n.. 92 Bell's palsy, 534 Bellv, posterior, of omo-bvoid in., 378 Biceps m., 27, 111. 24, 70, 76, 77, 110, 115, 128, 194, 200 action. 119 blood supply, 119 Biceps m., grooves. 27 head, accessory. 119 lonu. 115, 118 short, 1111.115,118 insertion, 119 origin, 119 relations, 119 rupture, 130 tendon, 110, 115, 118, 128, 131, 135, 140, 141 Bicipital aponeurosis, 119 relation, to brachial a., 11!) branch of anterior circumflex a., .-9 nerve. 91 fascia. 110, 115. 128, 131, 135, 140, 141 groove. 27 I'.ivcnter cer\ ids in., 402 Blood-letting. 104 Body of scapula, fracture. 270 pituitary, 579 Bone, cheek', liill frontal, sinuses, 455 growth, 259 marrow, :.'59 metacarpal, 169 sesamoid, of thumb, :!7 Bones, long, anatomy. _'.">(; cancellons tis.-ue. '.'59 nourishment, 259 of cranium, -15:2 of upper extremity, develop- ment, 2(>6 Brachial a . 10*, 110, 111, 115, 118, 128, 131, 135, 140, 141, 145 branches, 113, 111 course, 2* incision for ligatiou, 301 ligation. :vr, collateral drenla lion after, 308, 309 structures involved, 307 line, 108, 307, 122, 300 operation toexposc, 316, 317. 319 relations. 108, 307, 316, 317 at elbow, 328, 329 vena 1 comites. 113 nerve plexus, 7s, 76, 87 branches. 9O formation. 89 incision to expose, 301 motor points, 40 relations, to axillary a., 89 to subdavian a.. 89 stretching, 38, 311, 314 structures in- volved, 312 Brachialis aiiticus m.. 120, 115, 118, 128, 131, 135, 140. 141, 184, 194, 200, 345, 347 Brachialis anticus m.. action. 120 blood supply, 120 insertion. 120 nerve supply, 120 origin, 120 relations, 120 Brachio-radialia m., 197 Brain, arachnoid membrane, 573 compression, 572 membranes, 5i>* preser\ation. 581 removal. .~>72 Bronchi, jiosition. r!(i1 Buccal a., 54*. 546, 559 branch of eervico-facial n., 533 of facial n.. 473. 477. 484 glands. 502 Ivmphatic glands. 5d(i nerve. 552, 542, 550, 559 portion of Stenson's duct, 523 Buccinator m., 501. 485, 491. 542, 550 action, 502 insertion. 501 nerve supply, 502 origin, 501 relations, 501 Bucco-pharyngeal fascia, 501 Burdach, column, 444 Bursa, carpal, great, 157, 166 abscess, 158 of mammary gland, 54 palmar, 157 abscess. 158 subaeromial, inflammation, 223 subdeltoid, 379 abscess. :!79 inflammation, 379 Bursa 1 of elbow, 228 of oleeranon. 188 of shoulder-joint. 223 of upper extremity, 28 Canal, central, of spinal cord. 43(i tumors within, 449 of Huguier, 555 osteo-librons, of hand, 1(!7 Cancellous tissue of long bone, 259 Canprnm oris, 490 Cauthus, external, 512 internal. 512 Cap of shoulder, 378 Capsnlar ligament of atlanto- axoid joint, 419, 417, 421 of carpal joint, 238 608 INDEX. Capsular ligament ol' carpo-incta- carpal joint, first set, 230, 231 second sc-t. 2 1.") i.foccipito-atlantal ioiiit, I-;:;, 417 of radio-carpal joint. 235 lit' shoulder - joint. 223, 218 of vertebrae, 416. 413 een ical. 417 Capsule of niaiiiniary gland. 54 Carcinoma, course of metastasis, 07 edema of ami, -1 ol' axillary lymphatic glands, 92 of mammary gland. 53. 57 of tubercles nf Montgomery. 57 Caries ot' vertebra'. 5 -Hi Carotid a., 546 common, line. 487 external. 542, 550 internal, 593. 579 course, "lit:! lobe of parotid ".land. .">_'> Carpal arch, anterior, 173 hemorrhage, 180 posterior, 310, 194 branches, 210 arterv. anterior, radial, 144. 135, 145, 173, 177 uluar, 143, 135, 140, 141, 145, 173, 177 anastomosis, 148 posterior, radial, 211, 145, 177, 200, 206 nl liar, 211. 140, 141, 177, 200, 206 recurrent, 180, 145, 173, 177 anastomosis. IMIJ course, 180 bursa, 157 alisccss. 15~< great. 166 joints, 23-i blood supply, 242 formation, 23-< ligaments, 238 movements, 242 nerve supply, 242 ligament, dorsal. 231 Carpo-metaenrpnl joint, 231, 235 first set, 2 12 blood snpplv. 845 formation, 242 ligaments. 242 movements, 215 nerve supplv, 345 second set, 24,"> blood snpplv, 245 Carpo-metacarpal joint, second set. forma- tion, :2 15 ligaments. '. 1"> movements, :_' l.~> nerve snpplv. 245 ligaments, anterior, 235 Carpus, centers of ossification, 269 dcvelo]>ment, 269 dislocation. 255 st inclines involved, 2."if) excision, 203 i'ructiire, 27s displacement, 278 front of, 31 pisilorm bone. 31 synovia I membrane, 242 Cartilage, articular, 212 interarticnlar, 210, 214 of pinna, 529 tarsal, \", . 510 Carnncola lachrymal is, 512. 515. 513 Canda C(|iiiiia, 435. 429, 433 t'a\enioiis sinus, 5S9. 579 relation of. to (Jasserian <;an<:lion. o^ii Cavity, glenoid, 219 Cells, gplenoidal, 578 Centers of ossification of carpus. 269 of clavicle. 2(i(i ot' hnmcnis. :.'(i'i of metacarpal IKHICS, 2(i!* of ])halan^es. 2liU of radius, 266 of scapula, 266 of ulna, 269 Central canal of spinal cord, 4"6 Cephalic groove. 64 vein, 27, 103. 59, 70, 71, 76, 77, 100. 110, 128 median. 103, 100, 128 C'erebellar nerve tract. 1 13 Cerebral fissures, lines. 453 vein, superior. 573 Cervical enlargement of spinal cord. 428 intertransversales m.. IOT nerve, eighth, 86 posterior division. 410 fifth, 87 posterior division, 410 first, posterior primary division, 409 fourth. 87 posterior division, 410 second, posterior primary division. H>!i seventh, 87 posterior division, 410 sixth, 87 posterior division, 410 third, posterior division, 410 nerves, oriuin, 361 Cervical plexus, posterior. ol'Cru- veilhier, 4d!t vein, deep, Hi:!. 509 \ertcbrie, abscess, ll.'iii diseases, 3."><; spine of seventh. ::iil of sixth. 3.'i(i ( 'ervicalisasceiidens m.. 4(111, 396, 397 action. Hid insertion, 400 nerve supjilv. 400 origin, 400 relations, 400 CiTvico-hasilar 'ligament, -I'.'O, 421 Check ligament, -123 Cheek bone. 460 Chest, auscultation. 3."i2 ]ierens.-ion. '.',~fl supciticial fascia, I- Chordu tvmpaui n.. "I'M. 542. 550, 559 Chorda- Willisii. .":: Ciliary in., of orbicularis jialpe- brarnm, 497 Circular method of amputation, 280 modified. '.'-(I sinus. .-,!:u. 578, 579 Circulation, collateral, after liga- tion of axillarv a.. 306 brachial a., ::os. 309 radial a , 311 nlnar a.. 311 of arm, diauram, 324 of clllONV. Ill of fingers, diagram, 325 of forearm, diagram, 325 of hand, diagram, 325 Circnlns tonsillaris, 562 venosus. llaller. .">7 Circumflex a., 184, 185 anterior, H9. 76, 77, 111, 118 anastomosis. s,", 89 branches. .!! in excision of shoul- der-joint, 89 posterior. 85. Ill, 184, 185 anastomosis, 85, tij incision, 40 iigation, 306 structures in- volved, 300 operation to expuse, 341 nerve, 90. 124, 380, 76, 77, 87, 184, 185, 381 branches. 90. 124 cutaneous branch, 97 irritation, 314 motor points, 41 operation to expose. 341 stretching, 306 structures involved, 306 trauma, 124 vein, posterior, 341 Cirsoid aneurysm, 470, 463 INDEX. 609 Classilication of joints, 215 Clavicle, K 62 articulations. 1.- ccuters ol' ossilication, 266 development, 206 dislocation. 1-\ 2H structures involved, 248 excision, 2(io structures involved, 260 fracture, 18, 269 displacement, 270, 268 structures involved, 269 sarcoma, '.'lil Clavi-pectoral fascia, 67 Clavus. 5(11 Clawed hand, 277 Coccyx, 361 Collateral circulation after ligation of axillary a., 306 hrachial a., 308, 309 radial a., .'!! 1 ulnar a., 311 digital a., 162, 140, 159, 173, 177 line, 176 nerve, 162. 156, 159 Colics' fracture, 277, 276 displacement, 277, 276 structures involved, 278 Column of Burdach, 444 ofTurck, -t-13 Columna, nasal, 158 Comedones. 521 Comes nervi mediani, 147 Commissure, gray, of spinal cord, 436 palpcbral, f)12 white, of spinal cord, 436 Common carotid a., line, 487 interosseous a.. 147, 140, 141, 145, 203 ligament, anterior, of verte- bra.-, 412, 413, 417 posterior, of vertebrae 412, 413 Communications of facial v., 511 Compartments of anterior annular ligament, 157, 167 osteo-l'ascial, of arm, 108 posterior annular ligament, 197 Complexus m., 401, 373, 396, 397 action, 402 blood supply, 402 insertion, 401 nerve supply, 402 origin, 401 relations, 401 Compression, digital, of axillary a., 82 of brain, 572 Compressor nnrium minor m., 491 nasi m., 4!)3, 491 action, 493 insertion, 493 nerve supply, 493 origin, 493 Concha, 524, 525 C'ondyles of humerus, 28 fracture, 274 displacement in, 274 39 Condyles of humerus. fractures, structures imohcil, 274 Congenital variations of mam- mar/ gland, li.'i Congestion of conjunctiva, 515 of seal)). 1711 Conjunctiva. 515, 496, 517 congestion, 515 corneal portion, 515 palpcbral ]>ortion, 515 reflected portion. 515 sclerotic portion, 515 Conoid ligament, 221, 218 Contents of anatomic snuff-box, 32 ofaxilla, .-0 of infra-clavicular triangle, deep, 73 superlicial, f>7, 70 of osteo-l'ascial compartments of arm, 108 of parotid gland, 521 of ptervgo-maxillary region, 543 of spheno-maxillary fossa. 557 of suboccipital triangle, 407 of triangle at elbow, 130 of zygomatic fossa, 557 Contraction of fingers, Dupuy- tren's, 161 Conns medullaris, 428 Cooper, Sir Astley, ligament, 54 Coraco-acromial arch, '!'!'! ligament, 27, 222, 115, 118, 218, 219 Coraco-brachialis m., 120, 65, 70, 76, 77, 110, 115, 118 action, 120 blood supply, 120 insertion, 120 nerve supply, 120 origin, 120 relations, 120 Coraco-clavicular ligament, 221 Coraco-humeral ligament, 223, 218 Corucoid process, 18, 27(1, 43, 115 fracture, 270 Cord, spinal, 429, 439 arachnoid, 431, 429 areas, motor, 445 reflex, 445 sensory, 445 arteries, 444 blood supply, 427 central canal, 436 tumors, 449 commissure, gray, 436 white, 436 disease, 446 dissection, 428 dura mater, 428. 429 enlargement, cervical, 428 lumbar, 428 fissures, 435 in fetus, 428 injuries, 449 lesions, 44(! median a., 444 Cord, spinal, membranes, 42*, 429 motor tract, degenera- tion in, 450 nerve tracts, 443, 441 pia mater, 432. 429 protection, 449 sections, 437 structure of, macro- scopic, 436 veins, 445 Corneal portion of conjunctiva, 515 Coronal suture, 452 Coronary a., inferior, of lip, 507, 472, 477, 504 anastomosis, 507 course, 507 superior, of lip, 507, 472, 477, 504 anastomosis, 507 Coronoid head of pronator radii teres m.. 140, 141 process of ulna, 278 fracture, 278 displacement, 278 structures in- volved, 278 Corrugatorsupercilii m., 498,496 action, 498 insertion, 498 nerve supply, 498 origin, 498 Costo-clavicular ligament, 216 Costo-coracoid membrane, 68, 62, 70 Cranial nerves, 579 Crauio-vertebral muscles, 41 posterior, 407 Cranium, bones of, 452 landmarks, 451, 453 Crest of ilium, 362 Crista Galli, 579 Crucial ligament of atlauto-axoid joint, 420, 421 Cruveilhier, cervical plexus, 409 Cuneiform bone, 31 Curvature of spine, 352 annular. 355, 359 lateral, 355, 358 normal, 358, 359 Cutaneous branch, dorsal, of ul- nar n., 151, 196, 97, 140, 141 external, of musculo- spiral n., 97, 100 inferior external, of mus- culo-spiral n., 96 of muscnlo-spiral n., 188, 195 internal, of muscnlo- spiral n., 103, 188, 77 of circumflex n., 97 of median n., 129 of ulnar n., 126, 151 palmar, of median n., 148, 97 of radial u., 196, 97 of ulnar n., 151, 97 610 INDEX. Cutaneous branch, superficial, of muscnio spiral n., 96 nerve, external, 126 course, 38 internal. 01, 06. 124, 76, 77, 87, 97, 100, 110, 128 brandies, 124, 97 course. :iS lesser im.Tii.-il, 103, ]6 of mctacarpa! bones, 269 of phalanges. 200 of radius. -;i;(i of scapula, 20(i of ulna, 2li!) Diagnosisof lobar pneumonia. 3.V" Diagram of axillary fascia, 62 of collateral circulation of arm, 324 of lingers, 325 of forearm, 325 of pectoral fascia, 62 Diaphragm of pituitary fossa, 581 Diaphragma selhc, 581 Digastric fossa, 455 nerve, 533 Digital a., collateral, 162. 140, 159, 173, 177 line, 176 dorsal, 211 anastomosis, 211 of hand, 161, 140, 141, 145, 156, 159, 173, 177 line, 176 of bifurcation, 37 relations. 102 compression of axillary a., 82 nerve, collateral, 103 156, 159 from median n., 167 from radial u., 97 from ulnar n., 162, 159 I'acinian bodies, 167 relations. 1(!7 Dilator uaris m., 403 action, 403 insertion. 403 nerve supply, 493 origin, 403' narium in., anterior. 491 posterior. 491 Dimple behind elbow, 28, 25 Diploe, 463 Diploic v. , 568, 569 Disarticulation of metacarpal bones, 284 structures involved, 284 of radio-carpal joint, 284 structures involved. 287 Discs, intervertebral, 412, 413, 425 Diseases involving facial v., 511 of spinal cord, 446 Di.-location at elbow, 252 at radio-carpal joint, 255 of biceps lendoll, 27 of carpus. 255 of clavicle. -il> of humerus, 18, 248, 29, 249 snbelavicular. 251 snhcoiacoid, 251 subglenoid, 27, 248 snbspiiions, 251 of metacarpal bones, 255 of phalanges, 256 of radius. -25 I and ulna, 252 of scapula, 222 of ulna, 255 of vertebra', 424 subelavieular, of humerus, 251 subcoracoid, 251 stibglcnoid, 27, 248 snbspinous, 251 Dislocations, general considera- tion, 247 Displacement in fracture. Colics'. of radius. 277, 276 of carpus, 278 of clavicle, 270, 268 of condvles of linmerns, 274 of coronoid process of ulna, 278 of humerns, condvles. 274 epiphysis, 273 intcrcondyloid, 274 neck, anatomic. '-'7:1 surgical, 273, 272 shaft, 273 su pi a-condyloid, 274 tuberositv, greater, 273 of metacarpal bones, 278 of neck, anatomic, of humerus, 273 surgical. of Ini- mern~. 27:1. 272 of olecranon process of ulna, 278 of phalanges, 270 of radius, 277, 276 and ulna, 278 of shaft of humerus, 276 of ulna. 27s snpra-condyloid, of hu- merns. 27 1 Dissection of arm. back, 188 front, 06 of auricular region, 524 of axilla, from before back- ward, 74, 76 from below upward, 95, 76 of back, 367 incision, 365 of arm, 188 of forearm. 105 of hand, 209 of deep infra-clavicular tri- angle, 73 L\DJ-:X. (ill Dissection of dura mater. 575 of liice. 4*9 incision, 461, 487 of forearm, liaek, 195 front, 125 of front of arm, ill! of forearm, 125 of hand, 152 of baud, back, 209 front, 152 of infra-clavicular triangle, deep, 73 sllpel tielal, (i7 of niemlirancs of brain, 571 of spinal cord, 428 of neck, incision, 487 of palm of hand, 152 of pectoral region, 48 of pterygo-maxillary region, 5 411 of scalp, 4(!5 of spinal cord, 428 of superficial infra-clavicular triangle, 67 of temporal region, 489, 485 of upper extremity. 47 Dorsal ligament of carpal joint, 238, 241 of carpo m ct a carpal joint, 212 of internietacarp.il joints, 245 vertebra;, abscess, 1556 caries, 356 Dn'salis iudicis a., 211, 145, 177, 200, 206 anastomosis, 211 pollicis a., 211, 145, 177, 200, 206 scapula; a., 86, 384. 76, 77, 84, 111, 185, 343, 385 anastomosis, 86, 384, 385 Dorsi-spinal veins, 425 Duct, nasal, 458 Stenson's, 522. 472, 477, 485, 491, 504 course, 522 divisions, buccal, 523 masseteric, 523 line, 487 relations, 522 Ducts, galactophorous, 54, 55 lacrymal, orifice of, 517 lactiferous, 54, 55 of Meibomian gland, 512 orifice, 517 Bupuytren's contraction, 161 Dura mater, of brain, 572, 573 attachment, 575 blood supply. 590 dissection, 575 layers, 575 iierve supply, 590 processes, 581, 578 pulsations. 575 sarcoma. 575 sinuses, 582, 579 hemorrhage from. 583 of spinal cord, 428, 429 E. Ear, external, 465, 524 arteries. ~>:.!!J divisions, 524 muscles, 529 extrinsic, 469 intrinsic, 529, 527 pinna, 524, 525 landmarks, 565 Ec/ema of nipple, 57 Edema of arm, 81 in carcinoma of mam- mary gland, 81 Eighth cervical n., posterior divi- sion, 410 cranial n., 579 Ellx>w, angle of, 17, 21 brachial a. at, 328, 329 collateral circulation, 114 dimple behind, 28, 25 dislocation, 252 excision, 262 structures involved, 2G2 landmarks. >-< ligaments, 227, 225 limits, :!1 median n.. 328, 329 nerves, 128 triangle, 130, 131 contents, 131 Elbow-joint, 17, 225 amputation through, 288 structures involved, 288 blood supply, 228 bursa-. 22- ' formation, 224 ligaments, 227 movements. 17. 228 nerve supplv, 228 relations, 227 synovial membrane, 228 synovitis, 22 Eleventh n., 593, 579 Embolism, fat, 259 Eminence, frontal, 455 hypotheuar, 32, 172 parietal, 456 thenar, 32, 171 muscles forming, 171 Encephalocele, 455 Enlargements of spinal cord, cer- vical, 428 lumbar, 428 Epiphysis of acromion process, 18 ununited, 266 of humerus, fracture, 273 Epistaxis, 507 ICpithelioma of mammary gland. 57 Epitrochlear gland, 104 Erector spinse m., 399, 396 blood supply. 399 insertion, !!!>!) nerve supply, 399 origin, 399 ' relations, 399 Erysipelas, 480 Excision of breast, arteries di- . vided, 58 of clavicle, 260 structures involved, 260 of elbow, 262 structures involved, 262 Excision of humerus, head, 261 shaft, 2(i2 structures involved, 262 of metacarpal bones, 264 structures involved, 264 of phalanges, 265 structures involved, 265 of radio-carpal joint, 263 structures involved, 264 of radius, 263 structures involved, 263 of shoulder-joint, 89, 261 structures involved, 261 of ulna, 263 structures involved, 263 Excisions, general considerations, 259. 260 " Exostosis, 260 Expression, facial, 460 Extensor brevis pollicis in., 207 carpi radiaiisbrcvior in., 198, 135, 140, 141, 184, 194 action, 198 blood supply, 198 insertion, 198 nerve supply, 198 origin, 198 relations, 198 longior m., 198, 128, 131, 135, 140, 141, 184, 194, 200 action, 198 blood supplv, 198 insertion, 198 nerve supply, 198 origin, 198 relations, 198 tendon, 206 nlnaris m., 201, 194 action, 202 blood supply, 202 insertion, 201 nerve supplv, 202 origin, 201 relations, 201 tendon, 200, 206 communisdigitorum m., 198, 184, 194 action, 201 blood supply, 201 insertion, 201 nerve supplv, 201 origin, 198 relations, 201 tendon, 2O6 iudicis m., 208, 200 action, 208 612 INDEX. Extensor indieism., liluod supply, insrrtion, 208 nerve supply, 208 origin, 275, 597 trephining in, 598 Extremity, upper, amputations, 279 anterior view, 40 arteries, ligation, 294 Extremitv. upper, arteries, lines, 300 articulations. 17, 215 bones of, development, 366 dissection. 47 divisions, 17 joints. 17, 215 landmarks, 17, 18 movements, 17 nerves, stretching, 311 posterior view. 41 surface markings, 17, 18 Eye, appendages. 512 landmarks, 457 Eyeball, 513 Eyebrow, 512 muscles, 494 Eyelashes. 512, 515 Eyelids, 512. 51(5 areolar tissue. 516 blood supply, 519 lymphatics, 519 muscles. .ISM nerve supply, 519 veins, 519 F. Face, abscess, 490 appearance, 456 arteries, 460, 472, 477, 504 dissection, 489 incision, 461, 487 fascia, superficial, 490 incision tor dissecting, 461, 487 landmarks, 456 lymphatics, 567 muscles, 490, 477, 491 nerves, 555, 473, 477, 484 skin, 489 surface markings, 456 vascularity, 511 veins, 509 wounds, 511 Facial a., 502, 472. 477, 484, 485, 504 anastomosis, 512 branches, 51)7 course, 502 line, 487 relations, 502 transverse. 508, 472, 477, 484, 504, 542 anastomosis, 508 expression, 460 nerve, 5:50, 592, 484, 485 branches, 530 bnccal branch, 533, 473, 477, 484 course, 530 digastric branch, 533 divisions of, facial, 530 intra-cranial, 530 temporal, 530 infra-maxillary branch, 484 infra-orbital branch, 473, 477, 484 Facial nerve, malar branch, 473, 477, 484 operation to expose, ."::(> paralysis, 534 stylo-hyoid branch. .'.:;:; supra-maxillarv branch, 534, 473, 477, 484 temporal branch, 47li. 473, 477, 484 vein, 50s, 477, 484, 485, 509 arterial blood in, 511 communications, 511 course, 511 deep, 551 diseases involving, 511 line. 487 relations, 511 transverse. 509 Facies Hippocratica, 457 Falx cerebelli, 581, 582, 578 cerebri, 576, 581, 582. 578 Fascia, axillary, 68, 74, 59 bicipital, ' 119, 110. 115, 128, 131, 135, 140, 141 clavi-pectoral, 67 deep, of arm, 100 back, lt-8 front, 107 of back, 371 of forearm, 101 back, 196 front, 129 palmar, 158 abscess, 158 pectoral, 67 infra-spinous, 380, 3K3 lumbar, 409. 396, 397 formation, 409 palmar, deep, 158, 156 abscess, 158 dividing line, 37 superficial, 153 parotid, 520 pectoral, 63, 59 superficial, of chest, 48 vessels, 48, 49 of face, 490 of forearm, front, 126 of front of arm. 96 of hand, front, 152 of pectoral region. 49 of scalp, 466, 463, 467 palmar, 153 supra-spinous, 383 temporal, 482, 484 abscess beneath, 482 density, 482 relations, 482 vertebral, 394, 373, 396 Fat embolism. 259 orbital, 496 Felon, deep, 168 superficial, Ki8 Fetal skeleton, skiagraph, 257 Fetus, spinal cord in, 428 Fibro-cartilage, interartieular, 221 interosseous, of carpal joint, 238 Fifth cervical n., posterior divi- sion, 410 nerve, 539, 592. 559, 579 branches, 539 L\'DEX. (513 Filuni teriiiinale, 42H, 432, 429, 433 ;s. back ol", lymphatics. 196 collateral circulation, 325 extensor in. ol', deep, 197 radial. 197 superficial, 197 First cervical n. , posterior primary division, 409 u., 5!)1 Fissiira palpebraruin, 512 Fissure of helix, 530 ol' Santorini, 5:!0, 527 of spiual cord, antero-laterul, 435 median. anterior, 435 posterior, 435 postero-lateral, 435 palpebral, 457, 513 Fissures, cereliral, lines, 453 Fistula, salivary, 523 Flap method of amputation, 281 Flexor brevis minimi digiti m., 179, 140, 141, 159, 173 action, 179 blood supply, 17!) insertion, 179 nerve supply, 179 origin, 17!) relations, 17!) pollicis m., 171, 140, 159, 206 action, 172 blood supply, 172 bead of, deep, 171 superficial, 171 insertion, 171 nerve supply, 172 origin, 171 relations, 172 carpi radialis in., 133, 110, 118, 131, 135, 173 action, 133 blood supply, 133 insertion, 133 nerve supply, 133 origin, 133 relations, 133 tendon, 135 ulnaris m., 134, 110, 118, 128, 131, 135, 140, 141, 185, 194, 200, 381 action, 134 blood supply, 134 heads, 134 Flexor carpi uluaris in. in ampu- tation of lore- ami, 134 insertion, 134 nerve supply, 134 origin, 134 relations, 134 tendon, 173 longus pollicis m., 138, 135, 140, 141 action, 138 blood supply, 138 insertion, l:;* ner\e supply, 138 origin, 138 relations, 138 tendon, 167, 140, 159, 173 ossis metacarpi minimi digiti m., 179. I'iitit Opponeus Minimi Digiti Muscle. profundus digitoruni m., 137, 140, 141, 200 action, 138 blood supply, 138 insertion, 137 nerve supply, 138 origin, 137 relations, 137 tendon, 137, 167, 159, 166, 173 sublimis digitoruni in., 134, 131 action, 137 blood supply, 137 head of, humer- al, 134 radial, 134, 140, 141 ulnar, 134 insertion, 137 nerve supply, 137 origin, 134 relations, 137 tendon, 167, 159, 166, 173 tendons, 167 insertion, 168 sheaths. 166 theca, 166 Folds of axilla, 27, 24 Fontauel, anterior, 452 posterior, 452 Foramen ciccum. 579 infra-orbital, 459, 563 magnum, superior, 582 mental, 459 occipital, superior, 582 of splieuo-maxillary fossa, 557 pterygo-palatine, 557 rotundum, 557 Foramen, spheno-palatinc, 557 superior occipital, "> s '- ( siipra-eoudyloid, :.'~ supra-orbital, 459 Forearm, 31 amputation, 287 flexor carpi ulnaris in. in, 134 structures involved, 287 arteries, 145 back of, dissection, 195 fascia, 196 muscles, 194 nerves, 195 veins, 101 collateral circulation. 325 cutaneous nerves, 97 Ihscia, 101 front of, dissection, 125 fascia, deep, 1 29 superficial, 126 veins, 100 intermuscular septum, 129 iuterosseous membrane, 234, 140, 235 landmarks, 31 lymphatics, 129 muscles, 130, 131 section of, transverse, 286 superficial arteries, 129 Formation of carpal joint, 238 of carpo-metacarpal joint, lirst set, 242 second set. > l."> of elbow-joint, 224 of intermetacarpal joints, 245 of lumbar fascia, 409 of medio-carpal joint, 241 of metacarpo-p h a 1 a n g e a 1 joints, 24(i of palmar arch, deep, 190 superficial, 161 of radio-carpal joint, 234 of radio-ulnar joint, inferior, 233 superior, 233 of scapulo-clavicuhir joints, 221 of shoulder-joint, 222 of steruo-clavicnlarjoint, 215 of suboccipital triangle, 407 Fossa, antecubital, 38 digastric, 455 infra-clavicular, 18 of antihelix, 524. 525 of helix, 524, 525 of scapula, 383 pituitary, diaphragm, 581 scaphoid, of ear, 524 spheno-maxillary, 557 contents, 557 foramina, 557 zygomatic, 557 ' contents, 557 Fourth cervical n., posterior divi- sion, 410 nerve, 592, 579 Fractures, compound, of skull, 571 general considerations, 269 intercondyloid, of humerus, 274 nerve injury following, 274 614 INDEX. Fractures of acromion process, 18, 270 of carpus, 278 of clavicle, 269 dis|ilacfiiieut in, 270, 268 of condyles of huinerus. 274 of coracuid process of scapula, 870 of coronoid process of ulna, 278 of humerus, 270 intrrcoml.vloid, 274 of anatomic neck, 273 of rondyles, 274 of epiphvses, 273 of shaft," 273 displacement, in 272 of surgical neck. 2":> of tnlierosity. greater. 273 snpra-condyloid, 274 of ruetacarpal bones, 27H of neck of luimenis, 273 of radius, 277 of scapula, '-'7H of olecranon process, 278 of phalanges. 279 of radius, 277 and ulna, 278 of scapula, 270 of spine, 270 of shaft of humeru.o, 273 of skull, base, 550 of spinal column, 449 of ulna, 278 of vertebra?, 424, 449 supra-condyloid, of humerus, 274 Front of arm, dissection, 96 muscles, 114 of forearm, dissection, 125 fascia, 126, 129 veins, 100 Frontal a., 470, 467, 472, 477, 484, 504 anastomosis, 470 bone, sinuses, 455 diploic v., 571, 569 eminences, 455 lymphatics, 479 sinuses, 517, 569, 573 suture, 452 vein, 509 Frontalis m., 479, 491. Vide Oceipito-frontalis Muscle. Fronto-spheuoid diploic v., 571, 569 Furrow, nuchal, 351 of fingers, 37 of wrist, 31 palmar, 34 flexor, 37 spinal, 351 a. Galactophorous ducts, 54, 55 Galen, vein, 578 Gal va no-puncture in treatment of aneurysm. 298 Ganglion, 197 Arnold's. 5.Vi rian. 594, 559, 579 branches, 594 relations, 594 to cavernous sinus, 589 removal, 595 Meckel's, 561. 550, 554 of Wrisberg. 200 otic, r>5.">. 554 splieuo-palatiue, 561 Gangrene following ligation of arteries. 304 rian ganglion, 594,559, 579 branches, .~i!)4 relations, 594 to cavernous sinus, 589 removal of, 595 Gingivul a.. ">4(i, .V)!( Glabella, 452, 458 Gland, epitrochlear, 104 lacrvmal, 517 parotid, 520, 472, 477, 491, 504 contents, 521 lobe, carotid. 520 glenoid. 5211 pterygoid, 520 removal, 522 sensory nerves, 521 wounds, 522 Glands, axillary lymphatic, 92 in carcinoma of mammary gland, 92 buccal, 502 lymphatic, auricular, poste- rior, 566 axillary, 92 buccal. 566 lingual, 567 mastoid, 566 maxillary, internal, 567 occipital, 566 of arm, 104 of head, 5(><> suboccipital. 566 mammary, 53, 55 acinoe, 55 ampulla:, 54, 55 blood supply, 57 capsule, 54 carcinoma, 53, 57 epithelioma, 57 in males, 53 lobes, 54 lobules, 54 lymphatics, 57 nerve supply, 57 structure, 54 supernumerary, 53 suspensory ligament, 54 veins, 57 Meibomian, 457, 516, 496, 517 ducts, 512 orifice, 517 of axilla. 27 (Hands, sebaceous, of nipple. 54 Gleno-hnmeral ligament, '.>.'.'> Glenoid cavity, 219 ligament of interphalangeal joint, 247 of inetacarpo-phalangcal joint. '. In of shoulder-joint, 223 lobe of parotid gland. .">:JO Glosso-pharyngeal n.. 593 Goll, nerve column, 4 14 Gower's nerve tract, 44:i Great palatine n., 554 Groove, bieipital. 27 cephalic, 64 for biceps muscle, 27 Growth of bone, '.!."><) Gustatory n.. ,~>52 (.N iirromastia, 63 Haller, circulus veuosus, 57 Hand, 32 abM'ess, 37 arteries, 145 back. 209 arteries, 206 dissection, 210 superficial veins, 101 tendons, 206 veins, 195 exteusor muscles of, deep, 197 radial, 197 superficial, 197 fascia, superficial, 152 landmarks, 32 lines of arteries, 35 palm of, dissection, 152 line for arteries, 176 skin, 152 triangle, 32 Harelip, 508 operation, 508 hemorrhage in, 508 Head, accessory, of biceps in., 119 coronoid, of pronator radii teres in., 140, 141 deep, of flexor brevis pollicis m., 171 of pronator radii teresm., 130 inner, of flexor brevis polli- cis m., 140 of triceps m., 128 long, of biceps m., 114, 115, 118 of triceps in.. 191, 380, 115, 118 lymphatic glands, 566 of flexor carpi ulnaris m., 134 sublimis digitorum in , humeral, 134 radial, 134, 140, 141 nl nar, 134 of hnmerns, 27 of median n. , 123 of triceps m., 191, 380, 115, 118 INDEX. 615 Head, outer, of flexor brevis polli- cis 111., 14O radial, of flexor sublimis digitorum in., 134, 140, 141 short, of biceps m., 119, 115, 118 superficial, of flexor . brevis pollieis in. , 171 of pronator radii teres m., i:JO veins, 529 Helicis major in., .V.'!), 527 minor m., 529, 527 Helix, 524, 525, 527 fissure, 530 fossa, 5:34, 525 Hematoma of scalp, 481 Hemorrhage, extra-dural, 575. 597 trephining in, 598 following ligatiou of arteries, 304 from artery of septum, 507 from carpal arch, 180, 187 from sinus of dura, 583 in abscess of axilla, 79 in operation for harelip, 508 into pterygo-maxillary re- gion, 556 Horizontal division of lateral sinus, 584 Homer's m., 497. Vide Tensor Tarsi Muscle. Huguier, caual, 555 Humeral branch of aeromio-tho- racic a., 85 anastomosis, 85 head of flexor snblimis digi- tornm m., 134 Humerns, centers of ossification, 266 condyles, 28 development, 266 dislocation, 18, 248,249 subclavian, 251 structures involved, 251, 252 subcoracoid, 251 structures involved, 251, 252 subglenoid, 27, 248 structures involved, 248, 252 excision of head, 261 of shaft, 262 fracture, 270 intercoiidyloid, 274 of condyles, 274 of epiphysis, 273 of neck, '273 of shaft. 273 of tnberosity, greater, 273 supra-condyloid, 274 head, 27 nutrient a., 114 tuberosity of, greater, 27, 185 lesser, 27 Hunter's method of treating aneu- rysm. 297. 295 Hypo-glossal n., 593 Hypothenar eminence, 32, 172 I. Iliac crest, 362 Ilio-costalis m., 3!)9, 396, 397 action. :!!>!> insertion. 399 nerve supply, 399 origin, 399 relations. 399 Impulse, motor, 450 course, 450 sensory, 450 course, 450 Incision for abscess of axilla, 79 In-east, 58 parotid, 522 for dissection of back, 365 of face, 461, 487 of neck, 487 for exposing axillary a., 64 facial n., 536 * infra-orbital n., 563 for ligatiug axillary a., 301 brachial a . 301 radial a., 301 subscapular a., 301 uluar a., 301 for musculo-spiral n., 94 for parotid abscess, 522 for posterior circumflex a., 41 for radial u., 301 for removing growth of ax- illa, 81 for stretching brachial plex- us, 301 median n.. 301 for ulnar n., 301 Wilde's, 455 Incisive a., 547. 546 branch of mvlo-liyoid n., 555, 559 Incisura iutertragica. 524, 525 Infants, mammary gland, 63 Inflammation of periosteum, 260 of scalp. 481 of sheath of flexor tendons, 157 of subacromial bnrsa, 223 Infra-clavicular fossa. 18 triangle, deep, 73, 71 contents, 73 dissection, 73 superficial. 67, 70 dissection, 67 Infra-maxillary branch of facial n., 534, 484 Infra-orbital artery, 540, 548, 484, 542, 546, 550, 559 anastomosis, 540 branch of facial n., 533, 473, 477, 484 foramen. 459, 563 margin. 4.V nerve, 539, 561, 473, 484, 559 branches. 539, 561 labial, 539, 484 nasal, 539, 484 palpebral, 539, 484 operation to expose, 563 structures involved, 563 Infra-orbital plexus of nerves, 533, 539 vein, 540 Infra-spiuatus m., 383, 184, 185, 373, 381 action, 383 blood supply, 383 insertion, 383 nerve supply, 383 origin, 383 relations. 383 Infra-spinons fascia. :!>(). 383 Infra-trochlear u., 473, 477, 484 Infusion, saline, 104 Inion, 455 Injuries to spinal cord, 449 Innominate v., 509 luterarticular cartilage, 216. 214 fibro-cartilage, 221 Intercarpal joints, 238, 231, 235 blood supply, 242 ligaments, 238 movements, 242 nerve supply, 242 ligaments, anterior, 235 Interclavicular ligaments, 216, 214 relations, 216 Intercondyloid fracture of bu- rn eras, 274 displacement, 274 structures involved, 274 Intercostal branch of internal mammary a., 48 muscles, external. 391 internal, 391 nerve, 87 vein, 425 Iiitercosto-humeral n., 91, 188, 59, 76, 77, 97 Intermetacarpal joints, 245 blood supply, 246 formation. 2-45 ligaments, 245 nerve supply, 246 Intermuscnlar septa of arm, 107 septum of arm, external, 107 internal, 107, 110 of forearm, 129 Interosseous a.. :!7, 140, 141, 159, 173 anterior, 147, 140, 141, 145, 177, 203 common, 147, 140, 141, 145, 203 dorsal. 145, 177, 206 first, 211 line, 176 palmar, 180, 145, 177 anastomosis, 180 course, 180 posterior. 208, 140, 141, 145, 194, 200, 203 anastomosis, 208 branches, 208 relations, 208 recurrent, 208, 111, 145, 200 second, 210 third, 210 616 INDEX. Interosseoiis libro-cai tilage of car- pal joint, >'.',* ligament of carpal joint, :2I1 of carp o-ni ct aca rpal joint, :M"i of intermetacarpal joint, 246 membrane of forearm, 1-13, 234, 140, 145, 203, 230, 235 miiM-le. 169 dorsal, 311, 173, 206 action, 212 blood supply, 212 insertion, 211 nerve supply, 211 origin, 212 relation, 212 insertion, 169 palmar, leT, 141, 173 action, 187 blood supply, 187 insertion, 1>7 nerve supply, 187 origin, 187 nerve, anterior, of median, 148 posterior, 209, 135, 140, 141, 200, 203 brandies, 209 relations, 209 Interpalpebral slit, 512 luterphalangeal joints, -217 blood supply, 247 ligaments, 247, 244 movements, 247 nerve supply, 247 position of, 37 synovial membrane, 247 Interspiuales m., 404 action, 407 blood supply, 403 insertion, 404 nerve supply, 407 origin, 404 Interspinons ligament, 416, 413 Intersiitural membrane, 481 Intertrausversales m., 407 action, 407 blood supply, 403 cervical, 407 insertion, 407 lumbar, 407 nerve supply, 407 origin, 407 relations, 407 tboracic, 407 Intertransverse ligament, 416 Intervertebral discs, 412, 413, 425 Intro-cranial division of facial n., 530 nerves, 591 course, 591 neurectomy of inferior maxil- lary n., 594 of superior maxillary n., 594 Intra-thecal course of spinal nerves, 435 Intrinsic m. of pinna, 527 Irritation of circumflex u., 314 of median n., 314 Irritation of musculo spiral n., 314 of ulnar n., ill 1 Iter chorda' anterius, 555 J. Joints, 212. Vide Articulations. Jugular v., anterior, 509 external, 509 line, 487 internal. 509 posterior. 509 K. Keratosis senilis. 457 Kidneys, position, 36'2 Knuckles. :!7 landmarks, 37 Kyphosis, 352, 358 Labial a., inferior. 507, 472, 477, 504, 546 anastomosis. 507 branch of infra-orbital n., 539, 561, 484, 559 Laerymal canalienli, 512, 517 caruncle, 513 duets, orifice of. 517 gland, 517 nerve, 539 punctum, 513 sac, 45, 517 abscess, 508 Lactiferous duets, 54, 55 Lacuna; lateral is, 583 Lacus lachrymal!?, 512 Lambda, 452 Lambdoid suture, 452 Landmarks of arm, 27. 21, 24, 25 of auricle, 405 of axilla, :27 of back, 353 of neck, 351 of shoulder, 352 of trunk, 351 of cranium, 451, 453 of ear, 565 of eye, 457 of face, 456 of forearm, 31 of hand, 32 of knuckles, 37 of neck, 351 of back, 351 of pinna, 565 of shoulder, 352 of back, 352 of trunk, 351 of back, 351 of upper extremity, 17 Lateral atlanto-axoid joint, 419 sinus, 584, 578, 579 course, 456 divisions, 584 line, 587, 585 thrombosis, 584 tributaries, 584 Lateralis nasi a., .MH anastomosis, 508 Latissimus dorsi in.. '.',~~>, 62, 65, 70, 71, 76, 77, 343, 373 action, :!7(! aponenrosis, 373. 396 blood supply, 376 insertion, 375 nerve supply, 376 origin, '.',!'> relations. .'i7ii tendon, 185 Layers of dura mater of brain, 575 of scalp, 465 Leeching, 5* 1 Length of arms, comparative. 1- Lesioiis of spinal cord, I Hi Levator anguli oris m., 500, 491 action, 500 insertion, 500 nerve supply, 500 origin, 500 scapulae m., 377, 87, 373 action, 377 blood supply, 377 insertion, 377 nerve supply, 377 origin, 377 relations, 377 labii inferioris in., 500 action, 500 insertion, 500 nerve supply, 500 origin, 500 superioris alo;que nasi m., 493, 491 action, 493 insertion, 493 nerve sup- ply, 493 origin, 493 relations, 493 muscle, 409, 491 action, 499 insertion, 499 nerve supply, 41)0 origin, 499 relations, 499 meuti m., 491. ride Leva- tor Labii Inferioris Muscle, palpebrse superioris m 519, 517 insertion, 498, 519 origin, 519 relations. 520 Levatores costarum m., 40), 397 action, 404 blood supply, 403 insertion, 404 nerve supply, 404 origin, 404 relations, 404 IXDKX. 617 lent, accessory, of shoulder, >>;; acromio-clavicular, inferior, 221. 218 superior, 221, 218, 219 auuular, of wrist, anterior. 129, 157,173, 159, 230 compartments, 167 relutions, 157 posterior, 129. 196, 194, 206 compartments, 197 anterior atlanto-axoid, 419 of elbow. 227, 225 of interphalangeal joint, 247 of metaearpo-phalangeal joint, 246 of Ridio-curpal joint, 237 atlanto-axoiil, 415 anterior, 419. 417 capsnlar, 417 posterior, 419 superlicial, 419 capsular, of atlanto-axoid joint, 119, 417, 421 of carpal joint, 238 of carpo-metacarpal joint, 245, 230, 231 of occipito-atlantal joint, 423, 417 of radio-carpal joint, 235 of shoulder-joint, 223, 218 of vertebra?, 415, 416, 413, 417 carpal, dorsal, 231 carpo-metacarpal, anterior, 235 cervico-hasilar, 420, 421 check, 423 common, anterior, of verte- bras, 417 posterior, of vertebrae, 412, 413 conoid, 221, 218, 219 coraco-acromial, 27, 222, 115, 118, 218, 219 eoraeo-clavicular. 221 coraco-humeral, 223, 218 costo-clavicnlar, 216 crucial, of atlanto-axoid joint, 420, 421 dorsal, of carpal joint, 238, 241 of carpo-m etacarpal joint, 242 of intennetacarpaljoint, 245 external tarsal, 494 gleno-humeral, 223 glenoid, 219 of interpbalangeal joint, 247 of metacarpo-phalangeal joint, 246 of shoulder, 223 inferior aeromio-clavicular, 221, 218 Ligament, inteivarpal, anterior, 235 interclavicular, 216, 214 relations. 216 internal lateral, of lower jaw, 543, 542, 550 tarsal, 494 interosseons. of carpal joint, 241 of carpo-metacarpal joint. :.' 15 of internietacarpal joint, 246 iuterspinous, 416. 413 intertrausverse, 416 lateral external, of elbow, -227, 225 of medio-carpal joint. 242 of ra d i o-c a rpa 1 joint, 237 of wrist. 230, 231 internal, of elbow-joint, 227, 225 of HUM! io-carpal joint, 242 of rad i o-car pal joint. 237 of wrist, 230. 231 of interphalangeal joint, 247 of metacarpo-phalangeal joint, 246 of' thumb, 247 of vertebne, 415 medio-carpal, anterior, 241 posterior. 241 metacarpal, 166 oblique, 143, 234, 145, 225 occipito-atlantal, 415 anterior, 423, 417 obli(|iie, 417 capsnhir, 417 lateral, 423, 417 posterior, 423. 406, 417 occipito-axoid, 420 occipito cervical, 420 occipito-odontoid, 420, 421 odontoid, 420 of atlanto-axoid joint, 419 of carpal joint, 238 of carpo-metacarpal joint, first set, 242' second set, 245 of elbow-joint. 227 of intermetacarpal joint, 245 of interphalangeal joint, 247, 244 of medio-carpal joint, 211 of metacarpo-phalangeal joint, 246. 244 of occipito-atlantal joint, 423 of occipito-axoid joint, 420 of radio-carpal joint, 234 of radio-ulnar joint, 233 of scapula, 222 of scapulo-elavicular joint, 221 of shoulder-joint, 223 of Sir Astley Cooper, 54 of spinal column. 412, 413 of sterno-clavicnlar joint, 216 of vertebra?, 412 Ligament of vertebral column, 412 orbicular, 225 orbito-tarsal, 516 palmar, of carpal joint. 238, 241 of carpo-metacarpal joint, 242 of intermetacarpal joint. 245 palpebral, 516 piso-metacarpal, 241 piso-uncinatc, 241 posterior annular. 129. I'M, 194, 206 compartments, 197 atlanto-axoid, 41!) of elbow-joint, 227, 225 of radio-carpal joint. 2::" of thumb, 247 ptcrygo-max illary, 501 radio-carpal, anterior. 2117. 230, 235 external, 237 posterior, 237, 231 radio-ulnar, anterior, 233. 230, 235 posterior. 233. 231 rhomboid, 216, 214 relations, 216 sterno clavicular, a n t erior, 216, 214 relations, 216 posterior, 216, 214 relations, 216 superficial atlanto axoid, 419 superior acromio-cla\ icnlar, 221, 218, 219 supra-scapular, 222 supra-spinous, 415, 396, 413 suspensory, of axilla, 08 of mammary gland, 54 of occipito-axoid joint, 420 tarsal, 494 transverse metacarpal, 37 of atlanto-axoid joint. 420 of intermetacarpal joint, 246 of scapula, 222, 218, 219 superficial, of hand, 152 trapezoid, 221, 218, 219 nlno carpal, 237 vaginal, of fingers, 167 vertebral, 412, 417 Ligamenta brevia, 168, 166 longa, 168. 166 snbtlava. 415. 417 Ligamentiim arcuatum externum, 409 denticulatum, 432, 429, 433 nuchse, 375, 415, 373, 396 Ligation of arteries, gangrene fol- lowing, 304 general considerations, 303 hemorrhage following, 304 of upper extremity, 294 of artery and vein, 81 618 I XI) EX. Ligation of axillary a., -"i. 304 collateral circula- tion. 306 of brachial a.. 301 collateral circula- tion, :;i)8, 3(i7 nerve'. 552, 542, 550, 559 brandies. 55:2 vein, 509 Lister's method of amputation, 282 Lobes of mammai v gland, 54 of parotid glaiid. 52o Lobule of ear. 521. 525 Lobules of mammary glaml, 54 Long huccal .. 552 thoracic a., 53, 76 Lougissimus dorsi m., 400, 396, 397 action, 400 blood supply, 400 insertion, 4oo nerve supply, 400 origin, 400 relations, 400 Longitudinal sinus, inferior, 588, 578 superior. 583, 573, 578, 579 course, 45(i line, 583 wounds, 5-'3 Longus colli m., nerve to, 87 Lordosis, 352. 358 Lumbar abscess, 356, 409 enlargement of spinal cord, 428 fascia. Id!). 386, 397 formation, 409 intertransversales m., 407 nerve, origin, 361 posterior division, 410 vertebrae, abscess, 356 caries, 356 spines, 361 Lumbricales m. of hand, lii-\ 140, 159, 169, 173 action, 168 blood supply, 168 insertion, 168, 169 nerve supply, 168 origin, 168 Lymphatic glands, auricular, 566 huccal, 566 lingual. 567 mastoid, 566 maxillary, 567 occipital, 566 of arm, 104, 105 of axilla, 92 in carcinoma of breast. 92 of head, 566 parotid, 521, 566 posterior pharyngeal, 567 submaxiliary, 566 suboccipital, 566 Lymphatics, auricular, posterior, 479 frontal, 17!) occipital. 17(1 of arm. loi. 105 of evelicls. 51!) of face. 567 of fingers, 1!)5 of mammary gland. 57 anastomosis, 57 of pectoral region. 53 of pinna, 5:2!l of pterygo-maxillary region, 551 of scalp, 476, 567 posterior auricular, 479 superficial, of forearm. 12!) of upper extremity, 104, 105 temporal, 479 M. Main en grifife, 277 Malar branch of facial u., 473, 477, 484 of orbital n., 55s of temporo-facial n.. 533 of temporo-malar n., 540 Mamma, 53, 55 Mammary abscess. 5- artcry, deep external, 58, 85 internal, anastomosis, 85 brandies. 4< perforating branch, 49 gland, 53, 55 abscess, 58 absence, 63 aciiuc, 55 adhesions, 58 ampulhe. 54. 55 anomalies, 63 blood supply, 57 capsule, 54 carcinoma. 53, 57 course of metastasis, 57 epithelioma, 57 excision, 58 in infants, (13 in males, 53 lobes, 54 lobules, 54 lymphatics, 57 anastomosis, 57 nerve supply, 57 structure, 54 supernumerary, 53, 63 suspensory ligament, 54 tumors, 58 Spence's test, 58 veins, 57 Mammilla, 54. Vide Nipple. Marrow of bone. 259 Masseter m., 523, 485, 491 action, 524 blood supply, 524 insertion, 523 nerve supply, 524 origin, 523 relations, 523 INDEX. 619 Masseterica.. 548. 484. 542, 546 nerve, .V>1, 485, 542 port ion <>r Stciison's duet, 5:23 Mastoid branch of priuceps cer- vicis a., UK; lymphatic glands, 566 process, 455 operations, 587 Maxillary a., internal, 543, 544, 484, 485, 542, 546, 550, 559 brandies. 547, 546 divisions, 547 division of internal maxillary a.. 547 Ivmphatic glands, internal, ' 567 nerve, inferior, 551, 594, 550, 559, 579 brandies, 551 neurectomy of, in- tracranial, 594 structures in- volved, 594 superior, 557, 562, 594, 542, 550, 579 branches, 558 course, 557 infra-orbital branch, 473 neurectomy of, in- tracranial, 594 structures in- volved, 594 vein, anterior, 551, 509 internal, 551, 509 Measurements of arm, 47 Meckel's ganglion, 561, 550, 554 branches, 561 removal, 563 structures involved, 563 space, 594 Median a., 148, 140 of spinal cord, 444 basilic v., 103, 100, 110, 128 cephalic v., 103, 100 infusion into, 104 nerve, 91, 123, 148, 162, 76, 77, 87, 110, 115, 118, 128, 131, 135, 159 branches, 123, 148, 162 course, 38 cutaneous branch, 129 palmar, 97 divisions, 162 heads, 123 incision for stretching, 301 irritation, 314 line, 122, 300 motor points, 40 operation to expose, 316, 317, 319 above wrist, 349 relations. 123, 148, 316, 317 Median nerve, relations, at elbow, 328, 329 stretching, 312, 313 structures involved, 312, 313 vein, 126, 100, 128 deep, 100, 128 Medio-carpal joint, 241 ligament, anterior, 241 posterior, '.1 1 1 Medulla spinalis, 428 Medulli-spimil v., 427 Meibomiau inlands, 457, 516, 496, 517 ducts, 512 orifice, 517 Membrana uictitaus, rudimen- tary, 515 Membrane, costo-coracoid, 68, 62, 70 iuterosseous. 143, 234, 141, 145, 203, 230, 235 intersutnral, 481 of brain. 568 of spinal cord, 428, 429 synovia!, 215 of atlanto-axoid joint, 419, 417 of carpal joint, 241 of carpo-metacarpal joint, 245 of carpus, 228 of elbow-joint, 228 of iutermetaoarpal joint, 246 of interphalangeal joint, 247 of metaearpo-phalangeal joint, 246 of radio-ulnar joints, 237 inferior, 234 superior, 233 of shoulder-joint, 223 Meuiugeal a., anterior, 598 middle, 456, 547, 597, 546, 550, 554. 559, 573, 578, 579 brandies, 597, 598 wounds, 598 posterior, 599 small, 547, 599, 546, 550, 559 vein, 599 Meningitis, spinal, 451 Meningocele, 455 Meningo-rachidian v., 427, 425 Mental a., 540, 547, 484, 546, 559 anastomosis, 540 branch of mylo-hyoid n., 555, 559 foramen, 459 nerve. 540, 473, 484, 550 Metacarpal a., 211, 145, 200, 206 bones, 169 development, 269 disarticulation, 284 structures involved, 284 dislocation, 255 Metacarpal bones, excision, 264 structures involved, 264 fracture, 27* displacement, 278 structures involved, 278 position of heads, 37 ligaments, transverse. 166 Metacarpo-phalangeal joint, 17, 246 blood supply, 246 formation, 246 ligaments, 246, 244 movements, 17, 246 nerve supply, 246 synovia! membrane, 246 Metacarpus, centers of ossifica- tion, 269 Metastasis, course of, in carci- noma of breast, 57 Method of amputation, circular, 280 modified, 280 flap, 281 Lister's, 282 oval, 283 Spence's, 282 Teale's, 281 of treating aneurysms, Anel's, 297 Antyllus', 297, 295 Brasdor's, 297, 295 coagulating m a t e - rial, 298 foreign body, 298 ga 1 v an o-puncture, 298 Hunter's, 297, 295 manipulation, 298 pressure, 297 "VVardrop's, 297, 295 Micromazia, 63 Miner's elbow, 188 Mobility of scalp, 480 Montgomery, tubercle, 54, 55 Motor areas of spinal cord, 445 impulse, voluntary, 450 course, 450 oculi n., 579 points, 47 of brachial nerve plexus, 40 of circumflex n. , 41 of median n. , 40 of musculo-spiral n.. 40 of posterior iuterosseous n. , 41 of subscapular n. , 40 of ulnar n. , 40 tracts of spinal cord, degen- eration in, 450 Mouth , 458 muscles, 498 Multifidus spinse m., 404, 397, 406 blood supply, 403 insertion, 404 nerve supply, 404 origin, 404 Muscle, abductor iudicis, 211, 159, 173, 206 620 L\DKX. Muscle, alnluctor iiiiniiiii digiti, 172. 140, 141, 159, 173, 206 pollicis, 17, 140, 141, 159 aecessorias, :','.>'.>. 396, 397 ad ilio-eostulem. I'iilc Aceessorins Muscle, adductor i>ldii|iie, of thumb, 171. I'iile Flexor Brevis Pollicis Mus- cle, pollicis, 17-2, 140, 141, 159, 206 anconens, 202, 184, 194, 200 anterior dilator nariuni, 491 antitragiens, 5:39, 527 ;itt<>lfiis aiin-ni. Hi!). 491 attrahens aurcm, 469, 491 axo-appendicular, 411 biceps, '27, 114. 119, 70, 76, 77, 110, 115, 128, 194, 200 biyenter cervicis, 402 brachialis anticus, 120, 115, 118,128, 131,135,140, 141, 184, 194, 200, 345 brachio-radialis, 197 buccinator, 501, 485, 491, 542, 550 cervical is ascendcns, 400. 396, 397 ciliary, of orbicularis palpe- brarnni. 497 complexns, 401, 373, 396, 397 compressor uariiim, 491 minor, 491 nasi, 493 coraco-brachialis, 120, 65, 70, 76, 77, 110, 115, 118 corrugator supercilii, 498, 496 cranio-vertebral, 407, 411 deltoid, 27, 378, 24, 65, 70, 71, 76, 77, 110, 115, 118, 184, 341, 373 depressor a he nasi, 494 angti I i oris, 491 labii iulenoris, 500, 491 dilator naris. 193 nariuni, anterior, 491 posterior. 491 erector spimu, 399, 396 extensor brevis pollicis, 207. t'iil/ Extensor Primi Internodii Pollicis Muscle. carpi radial is brevior, 198, 135, 140, 141, 194 longior, 198, 128, 131, 135, 140, 141, 184, 194, 200 nlnaris, 201, 194 communis digitorum, 198, 184, 194 indicia, 208, 200 Muscle, extensor lonuus pollicis. 207. I'iilt K\ten>or Sccunili Internodii Pollicis Muscle. minimi digiti, 201. 194 ossis metacarpi pollieis. 207, 194, 200 primi internodii pollicis, 207, 194, 200, 337 secundi internodii polli- cis. 2(17. 194, 200 external oblii|ue. 52, 65, 373, 396 ptervgoid, 543, 542 flexor brevis minimi digiti, 179. 140, 141, 159 pollicis, 171, 159, 206 carpi radialis. 133. 110, 118, 131, 135 ulnaris, 131, 110, 118, 128, 131, 135, 140, 141, 185, 194, 208 longus pollicis, 138,135, 140, 141 ossis mctacarpi minimi digiti, 179. Vide Op- ponens Minimi Digiti Muscle. prol'nndus digitorum, 137, 140, 141, 200 sublimis digitorum, 134, 131, 135 frontalis, 479. Vide Occipito- frontalis Muscle, helicis major, 529. 527 minor. 529, 527 Homer's 497. Vide. Tensor Tarsi Muscle. ilio-costalis, 399, 396, 397 inferior oblique, 496 rectus, 496 infra-spinatus, 383, 184, 185, 341, 373, 381 intercostal, external, 391 internal. 391 internal oblique, 52, 373, 396 pterygoid, 544, 542, 554, 550 interosseous, of hand, 141 latissimus dorsi, 375, 52, 62, 65, 70, 71, 76, 77, 373 levator anguli oris. 500. 491 scapulae, 377, 373 labii int'erioris, 500 snperioris, 499, 491 akeqne nasi, 493, 491 menti, 491 palpebrx snperioris, 519, 517 longissimus dorsi, 400, 396, 397 masseter, 523, 485, 491 mill ti fid us spinse, 404, 397, 406 mnsculus caninus. Vide Levator Angnli Oris Mus- cle. Muscle, oblique, external, 52, 65, 396 inferior, 496 internal. 52, 396 obliqnus anris, 529, 527 capitis inferiiiris. 408, 397. 406 superioris, 408,396, 397, 406 occipitalis. 17!). [ iil< Occip- ito-frontalis Muscle. occi|>ito-lrontalis, 479 omo-hyoid, 65 opponens minimi digiti, 179, 141, 173 pollicis. 171, 140, 141, 159 orbicularis ocnli. Vide Orbic- ularis Palpebrarnm Muscle. oris, 498, 491 palpebrarnm, 494, 491 palmaris brevis, 152. 156 longn~. 133. 110, 128, 131, 135 pannicnlus carnosus, 48 pcctoralis major. (i3, 52, 62, 65, 70, 71, 76, 77, 110 minor, 73, 62, 65, 76 platysma myoides, 48, 485, 491 ] posterior dilator nari urn, 491 scapular, 381 prouator qnadratns, 138, 135, 140, 141 radii teres, 130, 118, 128, 131, 135, 140, 141 pterygoid, external, 543, 542 'internal, 544, 542, 550, 554 pyramidalis nasi, 490, 491 quadratns menti. Vide De- pressor Labii Inferioris Muscle. reetns capitis ]>osticus major, 408. 397, 406 m i n o r, 408, 397, 406 inferior, 496 sternalis, (>'4 superior. 496 retrabens anrem, 4(>9. 491 rhonihoideus major, 377, 373 minor, 377,' 373 risorins, 498, 491 sacro-lunibalis. Vide Ilio- costalis Muscle. Santorini's. Vide Eisorins Muscle. sealenus posticns. 396 semispinalis colli, 403, 406 dorsi, 403, 396, 397, 406 serratus magnus, 387, 52, 65, 71, 76, 77, 373, 391 posticus int'erioris, 394, 373, 396 superioris, 393,373, 396 INDEX. 621 .Muscle, sphineterocnli. I'iili Or- bicularis Palpebrarum .Muscle, oris. I'iili Orhiciilaris ( Iris Muscle, spinalis colli, 401 dorsi, 401, 396, 397 splcnius, 394 capitis, 373, 396 el colli. I'iilr Sple- nius Muscle, eolli. 373, 396 sterno-hvoid, 65 stemo-maatoid, 65, 373 sterno-thyroid, 65 subaiiciiiicus. 192 subclavius, 68, 62, 71 subscapularis. 387, 62, 65, 71, 76, 77, 343, 390 superior reetus, 496 supiuator brevis, 202, 135, 140, 141, 200 longus, 197, 110, 115, 118, 128, 131, 135, 140, 141, 184, 194, 200, 345, 347 radii brevis. fide Supi- nator Brevis Muscle. longus. fidf Snpi- nator Longus Muscle, supra-spinatus, 383, 184, 185, 373, 381 temporal, 489. 485, 542, 550 tensor palati, 554 tarsi. 497, 496, 517 teres major, 380, 62, 65, 76, 77, 110, 184, 185, 343, 373, 390 minor, 3SO. 184, 185, 341, 373 trachelo-mastoid, 401, 396, 397 tragicus, 529, 527 transversal is colli, 400, 396, 397 transversiis auris, 529, 527 trape/.ius, 372. 65, 373 triceps, 188, 65, 70, 76, 77, 110, 184, 185, 381, 390 tripartite, 388 zygomaticus major. 500, 491 minor, 501, 491 , M uscles forming thenar eminence, 171 interossei. dorsal, 211, 169, 173, 206 palmar, 187, 173 interspinales, 404 intertrausversales, 407 intrinsic, of pinna, 527 levatores costarnm, 404, 397 lunibricales, 168, 140, 159, 169, 173 of arm, 114. 185 of back, 373, 396, 397 of ear, 469, 529 of eyebrows. 494 of eyelids, 494 of face, 490, 477, 491 of forearm, 130, 131, 194 Muscles of mouth, 498 of nose, 490 of scalp. 477, 491 of scapula, back, 185, 393 rotatorcs spime, 404 Muscular branch of hrachial a.. Ill of facial a., 5(17 of interosseous a., 208, 309 of median n.. 1 I- of princeps cervicis a., 403 Musculo-cutaneous n., 91, 123, 126. 76, 87, 100, 115, 118, 128, 131 branches, 123 course, 38 motor point, 40 posterior branch, 195 relations, 123 Musculo-spiral n., 91, 124, 192.76, 77, 87, 110, 135, 140, 141, 184, 200 blanches. 125 cutaneous branch, exter- nal, 100 inferior, 96 supe rior, 96 internal, 103, 188, 97 incision to expose, 41, 94 irritation, 314 motor points, 40 operation to expose, aboveelbow, 345,347 paralvsis. 125 relations, 125, 316, 317 stretching, 313 structures involved, 313 Mylo-hyoid a., 547, 542, 546, 550, 559 nerve, 555, 542, 550, 559 branches, 559 incisive branch, 555 mental branch, 555 N. Nares, anterior. 458 Nasal a., lateral, 477, 546, 559 branch of infra-orbital n., 539, 561, 484 of Meckel's ganglion, 562 columna, 458 duct, 458 nerve, 539, 561, 473, 484, 554, 559 external branch, 540 naso-labial branch, 493 of Meckel's ganglion, 562 superior, 562, 554 nerves, inferior, 554 septum, 578 Naso-labial branch of nasal n., 493 Naso-palatine a., 54*, 554 Naso-palatine branch of Meckel's ganglion. 562 Neck, anatomic, of humerus, 273 fracture, 273 displacement, 273 structures in- volved, 27:! of scapula, fracture. 270 structures in- volved, 270 back, 351 landmarks. 351 incision for dissection, 487 landmarks, ,">51 of radius, fracture, 277 surgical, of humerus, frac- ture, 273 displacem en t. 273, 272 structures in- involved. >?:! of scapula, fracture, 270 veins, 509 Nerve, abducent. 592 anterior auricular. 552 cutaneous, 52 superior dental, 561, 559 temporal, 542, 550 auditory, 593 auricular, anterior, .">.">> great, 473 posterior, 476, 530 auriculo-temporal, 476, 552, 473. 477, 484, 542, 550, 554, 559 divisions. 552 buccal. 533, 473, 477, 484, 542, 559 long, 552, 550 cervical, eighth, 87 posterior division, 410 fifth, 87 posterior division, 410 first, posterior primary division. 409 fourth, 87 posterior division, 410 second, posteriorprimary division, 409 seventh, 87 posterior division, 410 sixth, 87 posterior division, 410 third, posterior division, 410 cervico-facial, 533 branches, 533 chorda tympani, 555, 542, 550, 559 circumflex. 124, 380, 76, 77, 87, 184, 185, 381 branches, 90, 124 cutaneous branch, 97 irritation, 314 motor point, 41 operation to expose, 341 622 INDEX. Nerve, circumflex, stretching. 3iMi structures involved, 306 trauma. 1:21 collateral digital, 156 cranial, 579 cutaneous, anterior. 52 branch, dorsal, of ulnar, l. r >l. 196, 97, 140, 141 external, of mus- cnlo-spiral, 97, 100 interior external, of mnscnlo- s].iral, 188, 195 of nmsculo-spi- ral, 96 internal, ofmu-M-ulo spiral, 103, 188, 77 of circumflex, 97 of median, 1:211 of ulnar, 126, 1.11 palmar, of median, 1 18. 97 of radial, 196, 97 of nlnar,151, 97 superlicial, of mus- culo-spiral, 96 external, 126 course. :'," internal, 91, 96, 131, 76, 77, 87, 97, 100, 110, 128 branches, 124, 97 course, 38 lateral, 52 lesser internal, 103, 188, 195, 76, 77, 97, 110 of arm, 97 of back, 371, 369 of forearm, 97 of front of arm, 96 palmar, 1.12 deep temporal, .1.11 dental, anterior superior, 561, 559 inferior, 555, 542, 550, 559 middle superior, 558, 559 posterior superior, 558, 542, 550, 559 digastric, 533 digital, 167, 97, 159 collateral, 156, 159 I'acinian bodies on, 167 relations, 167 eighth cranial. 593. 579 eleventh cranial, 593, 579 external anterior thoracic, 70. 71 cutaneous. :N palatine, 554 respiratory, of Bell,79, 92 superlicial petrosal, 597 facial, .130, 59:2. 484, 485 branches, 530 bneeal branch, 533, 473, 477, 484 Nerve, facial, course, 530 digastric branch. 533 division of, facial, 530 intra cranial, 530 temporal. r>.",D infra-maxillary branch, 531. 484 infra-orbital branch. .133. 473, 477, 484 malar branch. 533. 473, 477, 484 operation to expose, 539 paralysis, 531 stylo-hyoid branch. 5.",.'! supra- maxillarv branch, 534, 473, 477, 484 temporal branch, 17ii. 473, 477, 484 fifth cranial, 539. 592. 559, 579 branches, 539 lirst cranial, 591 fourth cranial. 592. 579 glosso-pharyngeal, 593 gustatory. 552 hypoglossal, 593 incisive branch of mylo- hyoid. .15.1, 559 inferior dental, 555, 542, 550, 559 maxillary. 551, 591. 550, 559, 579 branches, 551 divisions, 551 neurectomy, intra- craiiial, 594 nasal, 554 infra-maxillary branch of cervico-l'acial. 534. 484 infra-orbital, 539, 559 branch of superior max- illary. 539, 561, 473, 484. 559 branches, 539, 561, 473, 484, 559 labial, 539, 484 nasal, 539, 484 palpebral, 539, 484 operation to exjiose, 563 structures in- volved, 563 infra-trochlear, 473, 477, 484 intercostal, first, 87 intcrcosto-hnmeral, 91, 188, 59, 76, 77, 97 internal cutaneous, 91, 96, 124, 76, 77, 87, 97, 100, 110, 128 branches, 121, 97 course, 38 interosseous, anterior, 148 posterior, 209, 135, 140, 141, 200, 203 branches. 209 relations, 209 iutra-cranial, 591 course. .191 labial, 539, 561, 484, 559 lacrymal, 539 lateral cutaneous, 52 Nerve, lesser internal cutaneous, 103. iss, U),l, 76, 77, 97, 110 lingual. 552. 542, 550, 559 brandies. .1,12 long buecal, 5.1:2 lower Mibscapular, motor point, 40 lumbar, origin, 361 posterior division, 410 malar branch of facial, 533, .lid. 473, 477, 484 of orbital. 558 masseteric, 551, 485, 542 maxillary, inferior, 551, 591. 550, 559, 579 branches, 551 neurectomy, intra- cranial, 594 structures in- volved, 591 superior, 557, 562. .191, 542, 550, 579 branches. .1.1-' course. 5.17 infra-orbital branch, 473 neurectomy, intra- eranial. .194 structures in- volved, 594 median. 91, 123, 148, 162. 76, 77, 87, 110, 115, 118, 128, 131, 135, 159 branches, 123, 148, 1(32 course. :;> cutaneous branch, 129 palmar, 97 divisions. Ki2 heads. 123 incision for stretching, 301 irritation. 314 line. 122, 300 motor points. 40 operation to expose. 316, 317, 319 above wrist, 349 relations. 123. 1 Is, 316, 317 at elbow. 328, 329 stretching. 312, 313 structures involved, 312, 313 mental. 540. 473, 484, 550 middle superior dental. 5.1<. 559 motor oculi. 579 musculo cutaneous. 91. 123. 126. 76, 77,87, 100, 115, 118, 128, 131 branches. 123 course. 3- motor points, 40 posterior branch, 195 relations. 123 musculo-spiral. 91. 124, 192, 76.77,87, 110, 135, 140', 141, 184, 200 branches, 125 L\DI'X. 623 Nerve, musculo-spiral. course. .'!- cutaneous branch, external, 1OO inferior c\tcr- nal, 96, 188, 1!).") internal, 103, 188, 97 superior, 96 incision to expose, 41, 94 irritation, 317 motor ]ioiiits, 40 operation to expose, 345, 347 paralysis, 125 relations, 125, 316, 317 stretching, 313 structures involved, 313 mylo-hyoicl, 555, 542, 550, 559 brandies, ,V>r>, 559 incisive branch, 555 mental branch, 555 nasal, 539, 561. 473, 484, 554, 559 external branch, 540 inferior, 554 naso-labial branch, 493 of Meckel's ganglion, 562 superior, 562, 554 naso-labial branch of uasal, 493 naso-palatine, 562, 554 ninth cranial, 593, 579 occipital, great, 368, 409, 476, 373, 406, 473, 477 small, 476, 473, 477 smallest, 410, 406 third, 368 occipitalis major, 476 minor, 47(3 oculomotor, 591 olfactory, 591, 554 ophthalmic, 559, 579 optic, 591, 579 orbital, 558, 542, 550, 559 of Meckel's ganglion, 561 temporal branch, 476, 473, 477, 484 palatine, anterior, 561 external, 562, 554 great, 554 posterior, 562, 554 palpebral, 539, 561, 484, 559 pathetic, 592 petrosal, superficial external, 5!)7 large, 5! 16 small, 51)6 pharyngeal, 562, 554 phrenic, 87 pneiimogastric, 593 posterior auricular, 476, 530 interosseous, motor point, 41 superior dental, 558, 542, 550, 559 Nerve, posterior temporal, 542, 550 ptervgo-palatine, 562 radial, 151, 196, 97, 131, 135, 140, 141 branches, 151, 100 course. 3* cutaneous branch. 196. 97 incision for stretching. 301 relations, 151. 328, 331 stretching, 313 structures involved, 313 ramus subeutaneus mala;, 558 rhomboid, 87 sacral, origin. :'.61 posterior division, 411 second cranial. .">!ll sensory, of parotid gland, 521 septal, of Meckel's ganglion, 562 snpra-maxillarv branch of facial. 534, 484 supra-orbital, 475, 473, 477, 484 neurectomy. 475 supra-scapular, 384, 76, 87 supra-sternal, 53 supra-trochlcar, 475, 473, 477 neurectomy. 475 temporal, anterior, 476, 550 branch of facial, 476, 533, 473, 477, 484 of orbital, 476, 558, 473, 477 posterior, 476, 542 superficial, 552 temjioro-facial, 533 branches, 533 temporo-malar, 558 tenth, 593, 579 third, 591 thoracic, external anterior, 90, 76, 87 internal anterior, 90, 76, 87 posterior or long, 92, 76, 77, 87 to stibclavius m., 87 tract, cerebellar, 443 Gowers', 443 of spinal cord, 443, 441 posterior, 444 pyramidal, 443 anterior, 443 lateral, 44:; trifacial, 539, 592 branches, 539 twelfth, 5!)3, 579 ulnar, 91, 123, 151. 162, 76, 77, 87, 110, 115, 118, 128, 131, 136, 140, 141, 159, 173, 185. 194, 200, 381 branches. 151. 162 course. ::- cutaneous branch, 126 Nerve, uluar, cutaneous branch. dorsal. 1!Mi. 97,140,141 palmar, 97 incision for stretching. 301 irritation, 314 line, 312, 122, 300 motor point, 40 operation in expose, 316, 317 relations, 123. 151, 162, 316, 317, 321, 328, 335 stretching. 312, 313 structures involved, 312, 313 trauma, 123 vagus, 593 Vidiau, 562, 554, 559 Nerves at elbow, 128 cervical, origin, 361 deep temporal, 551 injury following fracture, 274 of arm, 120 course. ;" of back, 367, 409 of face, 530, 473. 477, 484 of tbrearm, 195 of pectoral region, 53 of ptervgo-maxillary region, 551 of scalp, 475, 473, 477 of upper extremity, stretch- ing, 311 of Wrisberg, 91, 103, 124 origins of spinal, 351 plexus of, axillary, 89, 76, 87 branches, 90 formation, 89 incision for stretch- ing, 301 motor points, 40 pressure upon, 89 relations, 89 to snbclavian artery, 89 stretching, 38, 311, 314 structures in- volved, 312 basilar, 579 brachial. J'iile Axillary Nerve, cervical, posterior, of Cruveilhier, 409 infra-orbital, 533, 539 section, 38 si retching, 38 thoracic, posterior primary division, 410 to levator anguli scapula; m., 87 to longus colli m., 87 to sealeni m., 86 Nervi molles, 508 Neuralgia, trifacial, 562, 564 Neurectomy, intra-crauial, of in- ferior maxillary n., 594 of superior maxillarv u., 594 624 INDEX. Nenrectoniv i)l' supra-orbital n.. 17 :> ' of supra-tvochlcar n., 475 Xinth u., 5!).'!, 579 Nipple, 51, 55 areola, 5-1, 55 eczema. 57 retraction, 5- structure, 51 .supernumerary, 63 Xose. l.'i- Nose-bleed, 507 Nourishment of Ion;; holies. '.Mil N'ucliiil furrow. :!51 Nutrient a. of luimerus, 11-1, 111 O. Oblique ligament of forearm. 1 I.'!. 234'. 145, 225 muscle, external. 373, 396 inferior, 496 internal, 373, 396 superior, pulley for. 496 oceipilo-atliintal ligament, 417 Obliquns aiiris in., 529, 527 eapitis iuferioris in., -Kw. 397, 406 action, -1(1!) blood supplv, 403 insertion, 408 nerve supply, 409 origin. 10* relations. KIM superioris in., 408. 396, 397, 406 action, 408 blood supplv, 403 insertion, 10- nerve supply, 408 origin, 408 relations, 408 Occipital a.. 402, 470, 406, 467, 472, 477, 504 anastomosis, -170 brandies. 402 diploic v., 571, 569 foramen, superior, 582 lymphatic glands, 566 Ivmpliatics, 476 nerve, great, 308, 409, 476, 373, 406, 473, 477 small, 476. 473, 477 smallest, 410, 406 third, 368 protuberance, external, 455 sinus. 588, 579 vein, 50!) Occipitalis major n.. 476 minor n.. 176 muscle, 47!t. Vide Occipito- frontalis Muscle. Occipito-atlantal .joint, 423 blood supplv. 424 ligaments, 415. 42:!. 417 movements, 423' nerve supply, 424 Occipito-atlantal ligaments. 415 anterior. -12:!. 417 capsnlar. 417 lateral. 42::. 417 posterior. 423. 406,417 Occipito-axoid joint, ligaments, 120 ligaments. 1211 Oeei|iiti)-cer\ ienl ligament, 420 Occipito- frontalis aponeurosis, 479, 463, 491 muscle. 17!) action, 47!) aponcurosis, 479, 463, 491 blood supply. 17!l insertion. 179 uenc supply, 47!) origin, 4711 relations, 47!) Occipito-odontokl ligament, 420, 421 lateral, 42:'>, 421 Oculo-motor n., 51)1 Odontoid ligament, 420 ( Hccrauon process. 2* bursa, 188 fracture. 27-' displacement. 27- structures involved, 278 olfactory n.. 51)1, 554 tract. 554 Olixan body. 439 Omo-hyoid in., 378, 65 Operation for harelip, 508 hemorrhage in, 508 for removal of (iasserian ganglion, 5! 15 structures in- volved, 5115 of parotid gland, 522 for trifacial neuralgia, 563 on mastoid process, 5-7 to expose axillary a.. 316, 317 brachial a., 316, 317, 319 circumflex a.. 341 nerve, 341 facial n., 539 infra-orbital n.. 563 median n., 316, 317, 319 above w r i s t, 349 musculo-spiral n., 345, 347 posterior circumflex a., 341 radial a., in snuff-box, 339 subscapular a.. 343 nerve, 343 nlnar n., 316, 317 Ophthalmic a., 579 nerve, 559, 579 Opponens minimi digiti m.. 179, 141, 173 action, 179 blood supplv, 17!) insertion, 179 Opponens minimi digit! m.. ner\ c supply. 179 origin. 1711 relations. 17!l pollicis m.. 171, 140, 141, 159 action, 171 blood supply. 171 insertion, 171 nerve supply, 171 origin, 171 relations, 171 Optic n., 591, 579 Orbicular ligament, 233, 225 Orbieularis oculi in. ]'idi Orbic- ularisl'alpchrarum Muscle, oris m., 4!)s, 491 action, 4!)!l nerve supply, 499 relations. 499 palpebrarum m.. 4!)4, 491 action, 197 insertion. 4!>7 nerve supply. -I!I7 origin, 494 relations, 494 Orbital a., 472, 477, 504. 546 branch of MeckePs ganglion, 561 of superior maxillary n., 558 fat, 496 nerve. 542, 550, 559 temporal branch, 476, 473, 477, 484 vein, 509 Orbito-tarsal ligament. 516 Orifice of duct of Mcihomiau gland. 517 of laciymal duct. 517 Ossification centers of carpus. 2(19 of claxide. 260 of humerus, 266 of metacarpus, 269 of phalanges. 269 of radius. 2ii6 of scapula, 266 of ulna, 26!) Osteoblasts. 259 Osteo-fascial compartments of arm. Ids contents, 108 Ostco-librous canal of hand. 167 ( Isteo-genctic layer of periosteum, 259 Othematomata, 524 Otic ganglion. 555. 554 Oval method of amputation, 283 P. Pacchionian bodies, 572, 573 I'aciniau bodies of digital n., 167 I'aget's disease. 57 Palatine a., 5-18. 546 nerve, anterior. 561, 562 external. 554 great. 554 posterior, 562. 554 Palm. 32 dissection, 152 lines for arteries, 176 IXDKX. Palm. skin. 152 triangle, :i2 1'iiliiiiir arch, course, 37 deep. 17!), 145, 173, 177 branches. 1-0 {nurse, l-i> line, 122, 176, 300 relations, 180 superlieial. 147, 161, 145, 159, 177, 300 branches, 161 course, 161 formation, 161 line, 122, 176 relations, 161 wounds, 180 bursa, 157 abscess, 158 cutaneous branch of median n., 1)8, 97 of radial n., 196, 97 nfulnar n., 151, 97 nerve, 15:2 fascia, deep, 158, 156 abscess, 158 dividing Hue, 37 stiperlicial, 153 furrow, 37, 34 mterosseous a., 180, 145, 177 anastomosis, 180 course, 180 ligament of carpal joint, 238, 241 of carpo - metacarpal joint, 242 of intermetacarpal joint, 245 Palmaris brevis m., 152, 156 insertion, 152 nerve supply, 152 origin, 152 lougus m., 133, 110, 128, 131, 135 action, 134 blood supply, 133 insertion, 133 nerve supply, 134 origin, 133 relations, 133 tendon, 135, 159 Palpebrae, 512 Palpebral a., 546 branch of infra-orbital n., 539, 561, 484, 559 commissures, 512 fascia, 516 fissure, 457, 513 ligaments, 516 portion of conjunctiva, 515 Palsy, Bell's, 534 Pannicnlus carnosus m., 48 Papilla; lachrymalue, 512 Paralysis of facial n., 534 of musculo-spiral n., 125 of serratus magnns in., 79 Parietal eminences, 456 Parotid abscess, 521 incision, 522 fascia, 520 40 Parotid gland. 5:20, 472, 477, 491, 504 contents, 521 lobe of. carotid, 520 ' pterygoid. 52O relations. removal, 522 sensory nerve supply, 52) wounds, 522 lymphatic glands, 5:21, 566 Pathetic n., 592 Pectoral fascia, 63, 59 deep, 67 diagram. 62 region, abscess, 68 1 dissection, 48 nerves, .">:! superlieial fascia, 49 Pectoralis major in., 63, 52, 62, 65, 70, 71, 76, 77, 110 action, 64 blood supply, 67 in carcinoma of breast, 67 insertion, 64 nerve supply, G7 origin, 63 relations, 64 sheath, 63 tendon, 115, 118 minor m., 73, 62, 65, 76 action, 74 blood supply, 74 insertion, 73 nerve supply, 71 origin, 73 relations, 74 tendon, 118 Percussion of chest, 352 Perforating a. of hand, 180, 173, 177 anastomosis, 180 course, 180 branch, anterior, of intcrossei a., 211 of internal mammary a., 48, 49 Pericranium, 481, 463 Periosteum, 259 inflammation, 260 of spinal canal, 428 osteo-genetic layer, 259 Periostitis, 260 PCS anserinus, 534 Petit, triangle, 376, 52, 373 Petrosal n., superficial external, 507 large, 596 small, 596 sinus, inferior, 590, 578, 579 superior, 590, 579 Phalangeal joint, 17 Phalanges, amputation, 283 structures involved, 283 development, 269 dislocation, 256 structures involved, 256 excision, 265 structures involved, 265 Phalanges, fracture, 179 displacement in, -27!) Phalanx, centers of ossification of each, 269 Pharyngcal n., 562, 554 Phlegmonous erysipelas. 1-0 Phrenic n., 87 Pia mater of spinal cord, 432, 429 Pingnecuke, 516 Pinna. 165, 524, 5'2!l. 525 action. 5:2!) blood supply, 529 cartilage, 5:29 intrinsic muscles, 527 lymphatics. 529 iierve supply, 529 skin, 5:24 Pisitbrm bone of carpus, 31 Piso-metacarpal ligament, 241 Piso-imcinate ligament, 241 Pituitary body, 579 t'ossa, diaphragm, 5s 1 Platysma myokles m., 485, 491 origin, 48 Pleural sac, aspiration, 351 Plexus of nerves, axillary, 89, 76, 87 branches, 90 formation, 89 incision for stretch- ing, 301 motor points, 40 pressure upon, 89 relations, 89 stretching, 38, 311. 314 structures in- volved, 312 basilar, 579 brachial. Vide Axillary, cervical, posterior, of Cruveilhier, 409 infra-orbital, 533, 539 of veins, pterygoid, 551 parotidens, 534 Plica semilunaris. 515, 513 Pneumogastric n., 593 Pneumonia, lobar, diagnosis, 352 Polymastia, 63 Polymazia, 63 Polythelia, 63 Pons Varolii, 439 Pre-carpal arch, 148 Preservation of brain, 581 Pressure method of treating aneu- rysm, 297 upon axillary a., 81 plexus of nerves, 89 vein, 81 Princeps cervicis a., 402, 406 anastomosis, 402 branches, 402 pollicis a., 180, 140, 141, 145, 159, 173, 177 branches. 180 course, 180 line, 176 relations, 180 Process, acromion, 18, 43 epiphyses, 18 u'nunited, 266 626 INDEX. 1'roress, aeromion. fracture, 18, 270 coracoid. 18, 43, 115 'l~0 coronoid, ol' ulna, 1'racture, 278 cl is placement, 278 structures in- volved, 278 mastciid. I.V, uperations upon. 5-7 oleorauon, 28 fracture, :>7- displacement, 278 structures involved. 278 styloid, of radius, l!l supra-condyloid, _'- Processes of dura mater of brain, 581, 578 Processiis camlatiis, 527 Profunda a., inferior, 113 110. Ill, 115, 118, 128, 145 anastomosis, 114 superior. 113, 102. 110, 111, 145, 184, 194, 200 anastomosis, 113, 192 brandies, 113, 192 relations, 102 cvrvicisa., 403, 406 anastomoMs. 403 1'ronatorquadratus m.. 138, 135, 140, 141 ail ion, 143 blood supply, 138 insertion, 13* nerve supply, 138 origin, 13-< ' relations, 13- radii teresm., 130, 118, 128, 131, 135, 140, 141 action, 133 blood supply, 133 head, coronoid, 140,141 deep, 130 superficial, 130 insertion, 130 nerve supply, 133 origin. 130 relations, 130 Protection 1o spinal cord, 449 Protuberance, external occipital, 455 I'soas abscess. 35(i Pterion, 452 Pterygoid a.. 547, 542 external, 548, 546 internal, 548, 546 lobe of parotid gland, 520 muscle, external 543, 542 action, 544 blood supply. 544 insertion, 543 nerve supply, 544 Pterygoid muscle, external, mi gin, 543 relations, 544 internal, 541. 542,550. 554 action, 5 1 1 blood supply, 544 insertion, 544 nerve supply, 51 I origin, 5-1 1 relations, 544 plexus of veins, 551 Pterygo-maxillary ligament. 501 region, 540, 542 abscess, 556' contents. 513 dissection. ~> Id hemorrhage into. 55fi lymphatics, 551 nerves. 551 veins. 551 Pterygo-palatine a., 548. 546 Ibraincn. 557 nerve. 5l!2 Pulley for superior oblique in., 496 Pulsations of dura mate]' of brain, 575 of radial a., 32 Pulse, 32 absence, 81 double, 32, 144 Pulsus duplex, 32 I'nneta lacbrymalia, 458, 51-;. 496, 513 ' Pyramid, anterior, 439 Pyramidal nerve tract, anterior. I 13 lateral, 413 Pyramidalis nasi in., 490, 491 action, 493 insertion, 490 nerve supply, 493 origin, 490 relations, 490 Q Quadratns ineuti in., 500. F'/Vc Depressor Labii Inferioris Mus- cle. R. Radial a., 143, 210, 110, 111, 128, 131, 135, 140, 141, 145, 159, 173, 177, 194, 200, 206 branches, 144, 210 course, 31 incision for ligating, 301 ill snuff-box, 339 line of incision, 337 ligation. 310 collateral circula- tion, 311 structures involved. 310 line. 143, 309, 122, 176, 300 pulsation. 32 Radial a., recurrent. 144. 145 anastomosis. Ill relations. 1 13. -.'10. 328. 331, 333 to bieipital aponeii- rosis. 1111 vena comes. 128 head of llexor sublimis digi- torum m., 13 I nerve, 151. 19(i, 97, 131, 135. 140, 141 brain-lies. 151. 100 course. 3* cutaneous branch, 1'lii. 97 incision for stretching. 301 relations, 151. 328, 331 stretching, 313 structures involved. 313 pulse. 32 absence. 81 double, 32, 144 recurrent a., 144, 131, 135, 140, 141, 345, 347 anastomosis. 141 vein. 12fi. 195, 100, 101, 128, 339 Radialis indicia a., 180, 140, 141, 145, 159, 173, 177 course, 180 line, 170 Radio-carpal joint. 17, 234, 231. 235, 239 blood supply, " disarticulation, :.'.- 1 structures involved, 287 dislocation, 255 structures involved, 255 excision. 263 structures involved, 264 formation, 234 ligaments, 234 movements, 17, 238 nerve supply, 238 ligaments, anterior, 237, 230, 235 external, 237 posterior, 237, 231 Kadio-ulnar joint, inferior, 17, 233, 230 blood supply, 234 formation, 233 ligaments, 233 movements, 233 nerve supply, 234 superior, 17, 233 blood supply, 233 formation, 233 ligaments, 233 movements, 233 nerve supply, 233 synovitis, 237 ligaments. anterior, 233, 230, 235 posterior, 233, 231 Radius, 31, 200 INDEX. 627 K:ulius and ulna. fracture. 27- structures involved. 278 centers of os-iliration, 2H(> ilevelopinrnt, 2(i(i dislocation, 252, 25 I structures involved, 253, 25 1 excision. 263 structures involved, 263 fracture, 277 displacement. 277. 276 stnictnrcs involved. 277 position of head, 2S, 25 tuberosity. 2* Rainn.s subciituncus mala- n., 558 Rectus capitis posticns major m., 108, 397, 406 action, 408 blood supply, 403 insertion, 408 nerve supply. 408 origin, 408 relations, 40* minor in., 408, 397, 406 action, 408 blood supply, 103 insertion, 408 nerve supply, 408 origin, 408 relations, 408 muscle, inferior, 496 superior, 496 sternalis in., (> I li'ccnrrent a., carpal. 1*0, 145, 173, 177 anastomosis. 180 course. I -i i interosscoiis, 208. 145 posterior, 111, 200 radial, Ml, 131, 135, 140, 141, 345, 347 anastomosis. 144 ulnar, anterior, 147, 111, 140, 141, 145 a nastomosis. 1 17 posterior, 147, 111, 140, 141, 145, 200 anastomosis, 147 Reflected portion of conjunctiva, ."> 1 5 Kellex action, 445 areas of spinal cord, 445 K'cid's base line, 453 Removal of brain, 576 of Gasserian ganglion, 595 structures involved, 595 Respiratory n., external, of Bell, 92 1,'ctc. acromial, 85 Rctraheus aurem in., 46!), 491 liYtrahens aurem in., action, 469 insertion, 4blt nerve supply, 16, 214 relations, 216 nerve, 87 Rbomboidens major m.. 377. 373 action, ill- blood supply. 378 insertion. :'.77 ncnc supply, 377 origin. 377 n-lations. 377 minor m., 377, 373 action, 377 blood supply. 377 insertion. 377 nerve supply, 377 (infill. i!77 relations. 377 Ridges, superciliary. 152 tcni]M>ral. |.~>i; Kisorius m., 498, 491 action, 498 insertion, 498 nerve supply, 498 origin. In- Risus sardonicus, 4!l-< Roots of spinal nerves, anterior, 432 posterior, 432 Rotatores spina' m.. 40 I aelion, 101 blood supply, 403 insertion. 1(11 nerve supply, 404 origin, 404 relations, 404 Roundness of shoulder, 18 Rupture of biceps in., 130 a. Sac, laerymal, 458, 517 abscess. 508 plenral, aspiration. 351 Sacral n., origin, 301 posterior primary divi- sions. 411 vertebra?, 361 Saero-lmiibalism., 399. Vide Ilio- costalis Muscle. Sagittal suture, 452 Salivary fistula, 522 Santori'ni, fissure, 530. 527 muscle, 498. Vide Risorius Muscle. Sarcoma of clavicle, 361 of dura mater of brain, 575 of tubercle of Montgomery, 57 Scaleni m., nerve to, 87 Scalenns posticns m., 396 Scalp, 451, 465 abscess, 481 areolar tissue, 480 arteries, 452, 469, 472, 477, 504 congestion, 479 Scalp, dissection, !((."> lascia, -!;(>, 467 heinatoma. 1-1 inflammation. -1*1 layers, 4(i5, 463 lymphatics. I7(i. 5(>7 mobility, -HO muscles. 177. 491 nerves, 475, 473, 477 skin, 46(i tumors, 451. 4*0 veins. 470, 509 wounds, 466. 1-0 Scalping, 480 Scaphoid tbssa. 524 tubercle, .'!! Scapula. 351 acroiniou process of, fracture. 270 anastomosis of arteries around, 84, 385 angle of, inferior, :',<>'! back of, muscles, 185 body of, fracture, 270 centers of oilication. 2fiG coracoid process of, fracture, 270 development, 266 dislocation. 222 dorsuni, 43 fossa, 383 fractures, 270 struc'tures involved. 270 ligaments, 222 movements, 367 muscles of, attachment, 393 position. 362 spine. IS, 43, 184 fracture, 270 winged, 222, 362 Scapular a., posterior. 384. 84, 385 a n ast oin os is, 86, 384, 385 branches. :;- I origin. 3S4 relations, 384 Scapulo-clavienlar joint, 221, 218. 219 blood supply, 222 formation, 221 ligaments, 221 movements. 222 nerve supply, 222 relations, 222 Scapnlo-hunicral joint. Vide Shoulder joint. Sclerotic portion of conjunctiva, 515 Sebaceous gland of nipple, 54 Second cervical n., posterior prim- ary division, 409 cranial n., 5!)1 Section, transverse, of arm, 290, 291 of forearm, 286 Sections of spinal cord, 437 Semilunar lines of abdomen, 52 Semispinalis colli m., 403, 396, 397, 406 action, 404 blood supply, 403 insertion, 403 I.\J)EX. i.inalis culli m., nerve supply. Hi:! origin. In:; relations. 40:; dorsi m., 40:!. 396, 397, 406 action, -lit:! blood supply, 403 insertion, in:; nerve supply, 403 origin, -103 relations, HI:; i v arras ot' spinal con!. 445 impulse, 450 course, 450 nerves of parotid gland, 521 Septa, intcrnuisrular, ol'urni, 107 orliitale, 510 S.ptal branch of Meckel's gang- lion, 502 Septic matter, entrance of, into veins, 81 Septum, intcnnnscular. external, of arm, 107 internal, of arm, 107 of forearm, 129 of nose, artery, ',07, 477, 504 hemorrhage fro m, 507 Serratus niagniis m.. 3*7. 52, 65, 71, 76, 77, 373, 391 action, 388 blood supply, 388 insertion. 3S8 nerve supply, 388 origin, 387 paralysis, 79 relations, 388 posticus inferioris m., 394, 373, 396 action, 394 insertion, 394 nerve supply, :;:M origin, 394 relations, 391 superioris m., 393, 373, 396 action, 394 insertion, 393 nerve supply, 393 origin, 393 relations. 393 Sesanioid bone of thumb, .'!7, :.' 17 Seventh cervical nerves, posterior division, 410 cranial n., 592. 579 Shaft of humerns, fracture, 273 displacement, 273, 272 structures involved, 273 Sheath of arteries, 298 of axillary vessels, 80 of flexor tendons, 107, 166 inflammation, 157 of pectoralis major m., 63 synovial, of flexor tendons of fingers, 37 Shoulder, 362 Shoulder, back, 351 landmarks, 351 buliv arch, 18 cap, 378 dislocation. 2 18, 29 excision, 201 structures iiiMihed, 261 landmarks, 351 roundness, 18 Shoulder-joint. 17, 222, 218 abscess, 379 amputation, 293 structures involved, 293 blood supply, 224 bursa-. 223 excision, 89 formation, 222 ligaments. 22:'. movements. 224 nerve supply, 224 relations. 22 I synovial membrane, 223 synovitis, 223 Sigruoid sinus, 584, 579 course, 456 Sinus a he paiva-, 688 cavernous, relation to (iasse- rian ganglion. 589 circular, 590, 578, 579 frontal, 517, 569, 573 inferior longitudinal, 588, 578 petrosal, 590, 578, 579 lateral, 584, 578, 579 course, 150 divisions, 584 line, 587, 585 thrombosis, .">- I tributaries, 584 longitudinal, inferior, 588, 578 superior, 583, 578, 579 course, 450 line, 583 wound. 583 occipital, 588, 579 petrosal. inferior, 590, 578, 579 superior. ".90, 579 sigmoid, 579 course, 456 sphcno-parictal, 588 straight. .>'s. 578 superior longitudinal, 583, 578, 579 course, 456 line, 583 wound, 583 petrosal, 590, 579 transverse, 590, 578, 579 Sinuses, cavernous, 589, 579 of dura mater of brain. 5*2. 578, 579 hemorrhage from, 583 of frontal bone, 455 ; Sixth cervical n., posterior divi- sion, 410 cranial n., 592, 579 Skeleton, fetal, skiagraph. 257 Skiagraph of fetal skeleton, 257 , Skin of face, 4S9 of palm, 152 Skin of pinna, 524 of seal].. 400, 463 Skull, blood supply. -181 fracture. 55(i, f>7] Slit, iuterpalpebr.il, 512 Snoring, 501 Snutl'-box. anatomic, 32 Socia parotidis, 520, 522, 477, 491 Sjieiice's method of amputation, 282 test, 58 Sphenoidal cells, 578 Spheno-maxillary division of in- ternal maxillary a., 547 fossa, 557 contents. 557 foramina, 557 Spheno-palatine a., 548, 546 foramen, 557 ganglion, 561 nerve, 558, 554, 559 Spheno-parietal sinus, 588 Sphincter oculi in. Vide Orbicu- laris 1'aJpcbrariim .Muscle. oris in., 498. Viile Orbicu- laris (iris Muscle. Spina bih'da, 431 Spinal accessory n., 593 arteries, 427 lateral, 444 posterior, 444 artery, anterior, 444, 429, 433 median, 444 canal, periosteum, 428 tumors, 449 reins, 427 column, fracture, 449 ligaments, 412, 413 movements, 407, 416, 419 cord, 429, 439 arachnoid, 431, 429 areas of, motor, 445 reflex, 445 sensory, 445 arteries, 444 blood supply, 427 canal of, central, 436 tumors, 449 commissure of, gray, 436 white, 436 disease, 446 dissection, 428 dura mater, 428, 429 enlargement of, cervical, 428 lumbar, 428 fissures, 435 in fetus, 428 injuries to. 449 lesions, 446 median a., 444 membranes, 428, 429 motor tract of, degenera- tion in, 450 nerve tracts, 4 13. 441 pia mater, 432. 429 protection to, 449 sections, 437 structure of, macro- scopic, 436 INDEX, 629 Spinal cord, veins, 445 curvature, 352 angular, 359 lateral, 358 iii.rnuil, 358, 359 I'll now, 351 meningitis, 151 nerves. 368 intra-theeal course, 435 origin. 'M\ roots. 13'.' Spiualis eolli ra., 401 action. lo] insei'tion, 101 nerve supply, 401 origin, 401 relations. 101 dorei m., 401, 396, 397 action, 401 blood supply, 401 insertion, 401 nerve supply, 401 origin, 401 relations, 40l Spine, cervical, seventh, 361 sixth, 356 lumbar, lirst. second, third, fourth, fifth, 361 of scapula, 18, 43, 184 fracture, 27o sacral, third, 361 Spines of vertebra 1 , 352, 356 lumbar, 361 sacral, 361 thoracic, 361 Spleen, ]K)sition, 362 Splenins capitis et colli in., 3!M. J "/'(/< Splenins Muscle, muscle, 373, 396 colli m., 373, 396 muscle, 394 action, 394 insertion. 394 nerve supply, 394 origin, 394 relations, 394 Stenson's duct, 522, 473, 477, 485, 491, 504 course, 522 divisions, 523 line, 487 relations, 522 Stephanion, 456 Sterno-clavicular joint, 215, 214 blood supply, 216 formation, 215 ligaments, 216, 214 relations, 216 movements, 221 nerve supply, 221 Sterno-hvoid m., 65 Stcnio-niastoid m., 65, 373 Sterno-thyroid m., 65 Stertorous breathing, 501 Straight sinus, 588, 578 Stretching of axillary plexus of nerves, 38, 311, 314 structures in- volved, 312 of circumflex n., 312 of median n., 312, 313 of musculo-spiral n., 313 Stretching of nerves of upper ex- tremitv, 311 of radial n., 313 of nlnar n.. 312, :!13 Stylo-hvoid brunch of facial n. , Styloid process of radius. :!1 Subacromial bursu, inflammation, 223 Subauconeus in., 192 action. 192 nerve supply, 192 Siibaruchnoid sjiace of spinal cord 341 Subclavian a., relation of, to ax- illary plexus of nerves, 89 vein, 509 Subclavicular dislocation of 1m nienis. 251 structures involved. 251, 252 Subclavius m., 68, 62, 71 action, 73 blood supply, 73 nerve supply. 73, 87 Subeoracoid dislocation of hu- inerus. 251 structures involved, 251, 252 Subdeltoid bnrsa, 379 abscess. 379 inllanimation, 379 Subdural space of spinal cord, 431 Suhgleiioid dislocation of liu- inerus. _' l~ structures involved, 2K 252 Snbmammary cyst, 58 Subma.xillarv lymphatic glands, 566 Submental a.. 546 vein, 509 Suboccipital Ivmjihatic glands, 566 nerve, IDS, 40!). 406 triangle, 407, 406 contents, 4u7 formation, 107 Subscapular aponeurosis, 387 artery, 86, 66, 67, 76, 77, 84, 111, 385 anastomosis, 86, 385 brandies, 86 incision for ligating, 301 ligatiou, ::oii structures involved. 306 line, 86 operation to expose, 343 nerve, 90 lower, 76, 77, 87 motor point, 40 operation to expose, 343 middle or long, 90, 76, 77, 87 motor point, 40 operation to ex- pose, 343 upper. 90. 87 triangle, 86, 390 Subscapular vein, 343 Snliscapularis m., 3*7, 62, 65, 71, 76, 77, 343. 390 action. blood supply, 387 insertion, ."-" nerve supply, 387 origin, 387 relations, 387 Subspiuous dislocation of bu- menis, :>51 structures involved, 251, :.':-' Snbstantia gelatinosa Kolaudi, 436 Sulcns, delto-pectorul, 64 Superciliary ridges, 452 Superlicialis vohc a., 32, 144. 131, 135, 145, 159, 173, 177 line. 176 Supernumerary mammary gland, 53, <>:: nipple, 63 Snpinator brevis in., 202. 135, 140, 141, 200 action, 202 blood supply. 202 insertion. 202 nerve supply, 202 origin, 202 relations, 202 longus m., 197, 110, 115. 118, 128, 131, 135, 14O, 141 184. 194, 200, 345, 347 action, 198 blood supply, 198 insertion, 197 nerve supply, 198 origin, 197 relations, 197 radii brevis m., 202 longus m.. J97 Snpra-acroniial n., 53, 97 Supra-clavicular n., 53 Supru-coiidyloid foramen, 28 fracture of humenis, 274 process, 28 Supra-maxillary branch of facial n .. 534,473, 477, 484 Supra-orbital arches, 457 artery, 469, 467, 472, 477, 484, 504 anastomosis, 469 foramen, 459 nerve, 175, 473, 477, 484 neurectomy, 475 notch, 459 vein, 509 Supra-scapular a., 384, 84, 385 anastomosis, 85, 384, 385 relations. 384 ligament, 222 nerve, 384, 76, 87 vein, 509 Supra-spinatus m., 383, 184, 186, 373, 381 action, 384 blood supply, 384 insertion, 383 630 Snpra-spinatns in., nerve supply. 384 origin. 3-3 relations, 383 Supra, spinous fascia. 3-3 liniment, -11."). 396, 413 Supra-Menial n., 53 Supra-lrorlilear n., -175, 473, 477 neniectomy. 475 Surface markings of arm. 27. 21, 24, 25 of auricle, 465 nf axilla. 27 of back, 353 of neck, 351 of shoulder. 352 of trunk, 35 1 of cranium, 451, 453 of ear, 565 of elbow, 28 ol' eve. 157 of face, 456 of forearm. 31 of band. 32 of knuckles, 37 of neck, 351 of back. 351 of pinna. 5(i5 of shoulder, 352 of back, 351 of trunk, 351 of back. 351 of upper extremity, 17 Surgical neck of bumerns, frac- ture, 273 of scapula, fracture, 270 Suspensory ligament of axilla, ' 08 of mammary gland, 54 of occipito-axoid joint, 420 Suture, coronal, 452 frontal, 452 lanibdokl, 452 sagittal. 452 Synovial membrane, 215 of atlanto-axoiil joint, 419, 417 of carpal joint. 2 11 of c a r p o - metacarpal joint, 245 of carpus, 242 of elbow, 228 of intermetacarpal joint, 216 of interphalangeal joint, 217 of niedio-earpal joint, 242 of metacarpo-phalangeal joint, 246 of radio-carpal joint, ajn of radio-ulnar joint, 233, 234 of shoulder-joint, 223 Syuovitis of elbow, '-'-'- of radio-carpaljoint, 237 of shoulder-joint, 223 of wrist, 237 T. Tarsal cartilage. 457, 516 ligament, external, 494 internal, 494 Tcale's method of amputation, 281 Temporal a., 470 anterior, 470, 467, 472, 477, 504 deep. 517, 546, 542, 550 middle, 472, 477, 484, 504 posterior. 470, 467, 472 477, 504 anastomosis. 170 deep. 547, 542, 546 superficial, 472, 477, 484, 485, 504, 542. 546, 550 branch of facial n., 47(i, 533, 473, 477, 484 of orbital n., 47(i, 568, 473, 477, 484 division of facial n., 530 fascia, 482, 484 abscess beneath, 482 density. 4*2 relations, 482 lymphatics, 479 muscle, 48!), 485, 542, 550 action, 489 blood supply, 489 insertion. l-'!i nerve supply, 489 origin, 489 nerve, anterior, 476. 550 posterior, 476. 542 superficial, 552 nerves, deep. 551 region, 489, 485 ridges. 456 vein, middle, 509 superficial, 477, 484, 509 Teniporo-facial n., 533 branches, 533 Teuiporo-inalar n., 558 Temporo-maxillar.v v., 485, 509 Tenalgia crepitans, 32, 197 Tendons, extensor, 209 insertion, 210 flexor. 167 insertion, 168 sheaths, 166 theca. 166 Tendo oculi, 458, 494, 516 palpebrarum. 494 Teno-synovitis. 197 Tensor palati in.. 554 tarsi m., 497, 496, 517 action, 498 insertion, 497 nerve supply, 498 origin, 497 relations, 497 Tenth n., 593, 579 Tentorium cerebelli, 576, 581, 582, 578 Teres major in., 380, 62, 65, 76, 77, 110, 184, 185, 343, 373, 381, 390 Teres major in., action, 380 blood supply. 3-0 ilisorlion. 3-n nerve supply, 380 origin. 380 relations, ::-n minor in., 380, 184, 185, 341, 373, 381 action. 3-'ll blood supply, 3-n insertion. 3-0 nerve supply, 3-0 origin. 3-o n-liii ions, 3-0 Tot, Spence's, .">.- Tlieca of llexor tendons, 166 Thecitis, 32, 168 Thenar eminence, 32 muscles forming, 171 Third cervical n., posterior divi- sion, 410 cranial n., 591 Thoracic a.. 85 long, 53, 5*. 85 anastomosis, -5 superior, 82, 76 anastomosis. s5 intertransversales m., 407 nerve, external anterior, 90, 76, 87 internal anterior, !)0, 76, 87 posterior or long, 92, 76, 77, 87 primary division of spinal. 410 origin of spinal u., 361 vertebra', spines. 3111 Thorax, relations of viscera, 363 Thrombosis of lateral sinus. 5-1 Thumb, amputation, 37, :.' s I structures involved, 284 sesamoid bone, 37, 247 Thyroid v., middle. 509 superior. 509 Tic douloureux, 564 Tissue, adipose, of axilla, 95 areolar, of axilla, 95 of eyelids, 516 Tophi, 529 Torcular Heropbili, 455, 583 Trachelo-inastoid m., 401, 396. 397 action, 401 blood supply, 400 insertion, 401 nerve supply, 401 origin, 401 relations, 401 Tract, motor, of spinal cord, de- generation in. 450 olfactory. 554 Tragieus m.', 520. 527 Ttagus. 524, 525 Transversalis colli m.. 400, 396, 397, 509 action, 400 blood supply, 400 insertion, 400 nerve supply, 400 origin, 400 relations, 400 INDEX. 031 Ti-ausverse facial a., 508, 472, 477, 484, 504, 542 vein, 509 lines of abdomen, 52 .sinus, 590, 578, 579 Transversns auris ni., 529, 527 Trapezium, 31 Trapezius in., 372, 65, 373 action, 372 Wood supply, 372 insertion, 372 nerve supply, 372 origin, 372 relations, 372 Trapezoid liuamcnt, 221, 218, 219 Trauma of circumflex n., 124 of ulnar u., 123 Treatment of anenrysins, 204 Trephining in extra-dnral hemor- rhage, 598 Triangle at elbow, 130, 131 contents, 130 infra-clavicular, deep, 73, 71 dissection, 73 superficial, 07, 70 dissection, 07 of palm, 32 of Petit, 376, 52, 373 suboccipital, 407, 406 contents, 407 formation, 407 subscapnlar, 86, 390 Tributaries to lateral sinus, 584 Triceps m., ]H8, 65, 70, 76, 77, 110, 184, 185, 381, 390 action, 192 blood supply, 192 beads, 191 insertion, 191 nerve supply, 192 origin, 188 relations, 191 Trifaeial n., 592 neuralgia, 562 Trigeminal neuralgia, 564 Tripartite m., 388 Trunk, back, 351 landmarks, 351 Tubercle, Darwin's, 527 deltoid, 18 of Montgomery, 54, 55 of scaphoid, 31 Tuberosity, bicipital, of radius, 28 greater, of humerus, 27, 185 fracture, 273 lesser, of humerus. 27 Tumors of mammary gland, 58 of scalp, 451, 480 of spinal canal, 449 Twelfth n., 593, 579 Tympanic a., 547, 546, 550 IT. Ulna, 31 centers of ossification, 209 coronoid process of, fracture. 278 development, 209 I'lna. dislocation, 25.) structures involved, 255 excision, 203 structures involved, 203 fracture, 278 olecranou process of, fracture, 278 Ulnar a., 144. Ill, 131, 135, 140, 141, 145, 159, 173, 177 branches, 147 course, 31 guide for ligation, 134 incision for ligation, 301 ligation, 311 collateral circula- tion, 311 structures involved, 311 line, 144, 122, 176, 30O relations, 147, 328, 329 deflection, 17 head of flexor sublimis digi- torum m., 134 nerve, 91, 123, 151, 102, 76, 77, 87, 110, 115, 118, 128, 131, 136, 140, 141, 159, 173, 185, 194, 200, 381 branches, 151, 102 course, 38 cutaneous branches, 120 dorsal, 190, 97, 140, 141 palmar, 97 incision for stretching, 301 irritation, 314 line, 312, 122, 300 motor point, 40 operation to expose, 316, 317 relations, 123, 151, 162. 316, 317, 321, 328, 335 stretching. 312, 313 structures involved, 312, 313 trauma, 123 recurrent a., anterior, 147, 111, 140, 141, 145 anastomosis. 147 posterior, 147, 111, 140, 141, 145, 200 anastomosis. 147 vein, anterior, 126, 195, 100, 128 common, 100 posterior, 195, 100, 110, 128 Ulno-carpal ligaments, 237 Upper extremity, amputations. 279 anterior view, 40 arteries, ligation, 294 lines, 300 articulations, 17, 215 bones, development of, 266 dissection, 47 Upper extremity, divisions, 17 joints, 17, 215 landmarks, 17, 18 movements, 17 nerves, stretching, 311 posterior view, 41 surface markings, 17, 18 V. Vaginal ligament of fingers, 167 Vagus n., 593 Varicose aneurysm, 309, 295 Vasa aberrantia, 114 Vasciilarity of face, 511 Vein, angular, 470, 509 anterior .jugular, 509 maxillary, 551, 509 temporal diploic, 571, 569 auricular, posterior, 509 axillary, 80, 62, 71, 76, 77 pressure upon, 81 relations, 310, 317 wounds. 57. 80 basilic, 104, 100, 110, 115, 118, 128 median, 103, 100, 110, 128 infusions into, 104 cephalic, 27. 103, 59, 70, 71, 76, 77, 100, 110, 128 median, 103, 100, 128 cerebral, superior, 573 cervical, deep, 403, 509 circumflex, posterior. 341 deep cervical, 403, 509 facial, 551 external jugular, 509 line, 487 facial, 470, 508. 477, 484, 485, 509 arterial blood in, 511 communications, 511 course, 511 deep, 551 disease, 511 line, 487 transverse. 509 infra-orbital, 540 innominate, 509 intercostal, 425 internal jugular, 509 maxillary, 551. 509 jugular, anterior, 509 external, 5O9 line, 487 internal, 509 posterior, 509 lingual, 509 maxillary, anterior, 551, 509 internal, 551, 509 median, 126, 100, 128 basilic, 103, 100, 110, 128 infusion into, 104 deep, 100, 128 middle temporal, 509 thyroid, 509 occipital, 509 632 INDEX. Vein, occipital diploie. 571, 569 orl)itul, 509 radial, 126, l!ir>, 100, 101, 128, 339 subckivian, 509 submental, 509 snhscapnlar, 343 snperlicial temporal. 484, 509 superior thyroid, 509 supra-orbital, 509 supra-scapular. 509 temporal diploic, anterior, 571, 569 middle. 509 superficial, 484, 477, 509 temporo-maxillarv, 485, 509 thyroid, middle, 509 superior. 509 transversalis colli. 509 transverse facial, 509 nluar, anterior, 12(i, 195, 1OO, 128 common, 100 posterior, 195, 100 110, 128 vertebral, 509 Veins, diploic, 568, 569 dorsi-spiual. 425 entrance of septic matter into, 81 frontal, 571, 509 diploic, 571, 569 fronto-sphenoid, 571, 569 libation, HI nieclulli-spinal, 427 meningeal, 599 meningo-rachidean, 427, 425 of arm, 103, 100 of eyelids. 519 of /'ace, 509 of forearm, 100, 101 of Galen, 578 of hand, 195, 101 Veins of head, 509 of mammary gland, 57 of neck, 509 of ptci yuo-maxillary region, 551 of scalp. 470, 509 of spinal canal. 427 cord, 145 of upper extremity, 28 pterygoid plexus, 551 spinal, 425 Vena basis vertebrie. 127, 413, 425 comes of radial a.. 12- Venn- comites of aeromio-t horacic a.. 85 of braeliial a., 22, 77, 113 Venesection, 104 Vertebra, dislocations, 424 fractures, 424, 449 spine of seventh cervical. 361 of sixth cervical, l!56 of third sacral, 361 Vertebra. 1 , abscess in caries, '.}'>!> cervical, abscess, 356 diseases. o.~>(> dorsal, abscess, 356 caries, :!5!>- of palmar arches, I -it of parotid gland. 522 of scalp,. 4(i(i, 480- Wrisberg, ganglion, 200 nerve, 91, 103, 124 Wrist, 31 abscess. 32 furrows, 31 level, 31 Wrist-drop, 125. 277 Wrist-joint. I'iile Radio-carpal Joint. /ygomatic arch, 460 fossa, 557 contents, 557 Zygomaticus major m., 500, 491 action, 501 insertion, 500 nerve supply, 501 origin, 500 minor in., 501, 491 action, 501 insertion, 501 nerve supply, 501 origin, 501 THE LIBRARY UNIVERSITY OF CALIFORNIA San Francisco Medical Center THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW Books not returned on time are subject to fines according to the Library Lending Code. Books not in demand may be renewed if application is made before expiration of loan period. 30m-10,'61 (C3041s4)4128