Introduction and Background

A MANUAL OF DISSECTION PRACTICAL ANATOMY. FOUNDED ON GRAY AND GERRISH. BY WILLIAM T. ECKLEY, M.D., PROFESSOR OF ANATOMY IN THE MEDICAL AND DENTAL DEPARTMENTS OF THE UNIVERSITY OF ILLINOIS, THE CHICAGO SCHOOL OF ANATOMY AND PHYSIOLOGY, THE CHICAGO CLINICAL SCHOOL AND WEST SIDE TRAINING SCHOOL FOR NURSES, AND CORINNE B, ECKLEY, DEMONSTRATOR OF ANATOMY IN THE MEDICAL AND DENTAL DEPARTMENTS OF THE UNIVERSITY OF ILLINOIS AND CHICAGO SCHOOL OF ANATOMY AND PHYSIOLOGY, AND MEMBER OF THE ASSOCIATION OF AMERICAN ANATOMISTS. ILLUSTRATED WITH 220 ENGRAVINGS, 116 OF WHICH ARE COLORED. LEA BROTHERS & CO., PHILADELPHIA AND NEW YORK. 1908. y o™ Entered according to the Act of Congress, in the yeur 1902, by LEA BROTHERS & CO., In the Office of the Librarian of Congress. All rights reserved. DORNAN, PRINTER E34 £18 1903 ELMER F. CLAPP, M.D., FORMERLY PROFESSOR OF ANATOMY IN THE UNIVERSITY OF IOWA, IN RECOGNITION OF BIS SCHOLARLY ATTAINMENTS AND ABILITY AS A TEACHER OF HUMAN ANATOMY, amie ROOK 18 DEDICATED BY THE AUTHORS, HIS FORMER PUPILS. 41'700 PREFACE. Tue present work has a twofold purpose, namely, to provide the student with a detailed guide for dissection, and to answer the requirements of the physician and surgeon wishing to review the anatomy of any region. The directions for dissecting and identifying the various structures of the human body have been given in full detail, with particular care as to sequence, so that each item of instruction should appear in its natural and most useful relationship. The general arrangement adopted is, first, to give the landmarks, then the integu- mentary incisions, and, finally, the description and relations of succeeding anatom- ical entities. Special effort has been devoted toward achieving precision in direc- tions for locating every structure—a matter of the utmost importance, particularly for the surgeon. Inasmuch as most students prefer Gray and Gerrish, this Dissector has been prepared for practical use with either. The publishers have placed at our disposal the incomparable series of illustrations found in these two standard works. The student can, therefore, enjoy the advantage of having in the dissecting-room a full and detailed guide for his work, presenting to his eye the same pictures with which he is familiar in his study and class-room. Tt scarcely needs to be said that no dissector can take the place of a standard descriptive anatomy. The arrangement of these two classes of books is opposite and correlative, the text-books following the systemic order, and the dissectors being necessarily regional. To increase the usefulness of the present volume it has been developed along this line to such an extent that it might with propriety be entitled a Regional Anatomy as well as a Dissector. It is hoped that the careful and complete treatment of the various areas will enable it to serve the needs of the surgeon and post-mortem pathologist. Much effort has been bestowed upon the tables, owing to the advantage this method offers for the presentation of anatomical knowledge systematically and clearly. Acknowledgments are due to the following anatomists: Dr. De Lee Shaw has ad with absolute fidelity to Gray and Gerrish the blood vascular system ; Prepared the articles on metamerism and conduction paths of ain; Dr. H. E. Santee read the proof om dissection of the ‘holder and Conboy read proof of the sections on the “ee, vi PREFACE. thorax and abdomen, and rendered valuable service in advising the judicious parenthetic use of the new nomenclature; Dr. P. Gad Kitterman tabulated the meningeal vessels, and cranial and spinal nerves; Dr. J. S. Brown assisted in read- ing the proof, and, moreover, made valuable suggestions regarding the legitimate scope of the book; Dr. Mortimer Frank kindly furnished some of the illustra- tions. We are deeply indebted to Dr. Lewellys F. Barker for suggestions of a conservative nature looking to exactitude in dissecting-room study. Finally, acknowledgment is due to the works of Gray and Gerrish, on whose texts the present volume is founded, and from which most of the illustrations are drawn, Catcaco, November, 1902, CONTENT CHAPTER I. PAGE Tae Face . . . . . 7 CHAPTER II. Tue ScaLp, MENINGES AND BasE OF THE SKULL . . . . » " . 61 CHAPTER III. THE BRAIN.AND THE SPINAL CoRD © 7 ww eee eee OD CHAPTER IV. Tue Moura . . . . 76 CHAPTER V. Tue Eve . . . . . 86 CHAPTER VI. Tue OrcaNs oF HEARING eee 95 CHAPTER VII. Tue NECK. . . a . . 106 CHAPTER VIII. Tue THoracic aND SHOULDER REGIONS. . . é : . : : . 189 CHAPTER IX. Curangzous VEINS AND NERVES OF UPPER EXTREMITY—ANTERIOR REGION OF FoREARM. $ : 2 q . ‘ . 5 5 . . . + 150 CHAPTER X. THE PosTeRIoR REGION OF ARM AND FOREARM AND RADIAL RgGION OF FOREARM 166 CHAPTER XI. Tue Tuoracic WaLis . . . . . . 7 CHAPTER XII. THORAX—SUBDIVISIONS AND CONTENTS meee amc 18H CHAPTER XIII. Tue ABDOMINAL WALLS. . . . . : 200 CHAPTER XIV. IDENTIFICATION OF ABDOMINAL ORGANS AND OTHER STRUCTURES IN SITU . . 209 CHAPTER XV. @ . . . . 216 viii CONTENTS. CHAPTER XVI. THE ABDOMINAL AND PeLvic OrGans. .. CHAPTER XVII. THE ABDOMINAL VESSELS se ee CHAPTER XVIII. Tae Petvic OoTLet eee ee CHAPTER XIX. Curanzous Vessets AND NERVES OF THE Lower EXTREMITY CHAPTER XX. Tue Iniac REGION . Roe © #€ 3 CHAPTER XXI. THe ANTERIOR FemoraL REGIon . CHAPTER XXII. THE INTERNAL Femorat REGIon . CHAPTER XXIII. THe GLUTEAL REGION ee CHAPTER XXIV. Tue Posterior Femorau Recion . CHAPTER XXV. THE ANTERIOR TIBIOFIBULAR REGION . CHAPTER XXVI. THE PosTeRIOR TIBIOFIBULAR REGION CHAPTER XXVII. Tue Finutar ReGion CHAPTER XXVIII. Tue Soe oF THE Foor . CHAPTER XXIX. Tue Back . CHAPTER XXX. Tue Sympatnetic Nervous System CHAPTER XXXI. Tue Boop VascuLar System nr (By De Leg Suaw, M.D.) CHAPTER XXXII. Sensory AND Motor Conpuction Paris BETWEEN THE SPIES CEREBRAL CoRTEX (By ©. M, Jacksox, M.D) PAGE . 220 + 238 . 248 . 263 . 269 « 298 . 803 . 811 . 816 . 824 . 327 » 340 - 855 . 362 A MANUAL OF DISSECTION, CHAPTER I. THE FACE. Dissection and Identification. Fill the mouth with cotton and sew the lips together. Remove the integument as indicated in Fig. 1. Consult the illustrations and identify the structures found on the cadaver by comparison. Follow order given in text, viz.: mental, infra-orbital, pterygoid, supra-orbital structures, and parotid gland. After these have been studied then turn attention to the muscles, vessels, and nerves. Fic. 1. 1. Dissection of scalp. 2, 3, of auricular region, 4, 5, G, of face. 7, 8 of neck, Dissection of the head, face, and neck. (Gray.) The Mental Nerve. The mental nerve is the cutaneous part of the inferior dental, a branch of the third division of the trifacial. The inferior-dental, a sensory nerve, traverses the mandibular canal in the lower jaw, giving in its course branches to the teeth, called the dental ; to the gums, called the gingival. The cutaneous branches communicate with branches of the facial, a motor nerve. The Mental Artery is a branch of the inferior dental ; it emerges through the mental foramen. The inferior dental artery, a branch of the internal maxillary, in its course through the canal in the mandible, gives dental branches to the teeth, gingival to the gums. The mental artery, on emerging through the mental foramen, anastomoses with the inferior labial branch of the facial. The Infra-orbital Nerve emerges through the infra-orbital foramen with vessels of like name (foramen is under cover of the levator Jabii superioris muscle) and e ranch Communications between it and the facial which lies between the levator labii superioris and ‘The infra-orbital nerve is a continuation of the superior e fi a It traverses the sphenomaxillary fossa and giving dental branches to the upper teeth ; gingival branches 18 A MANUAL OF DISSECTION, to the gums; infra-orbital branches to the skin of the nose, eyelid, and upper lip, and is accompanied by the artery and veiu of same name. The Infra-orbital Artery emerges from the infra-orbital foramen, anastomoses with the facial, and is a branch of the internal maxillary, which in turn is a ter- minal of the external carotid artery. The artery traverses the infra-orbital canal in the floor of the orbit, giving dental branches to the teeth, gingival branches to the gums, cutaneous branches to the nose, eyelid, and upper lip. The veins accompany the artery, take the same name, traverse the same territory, convey the blood in an opposite direction, to the pterygoid plexus. Fig. 2. Terminations of supratrochienr. of tu fratrachtear \ of nasal, The nerves of the scalp, face, and side of the neck. (GAY ) The Pterygoid Plexus is formed by a confluence of veins from the deep parts of the face. It derives its name from its location on the external pterygoid muscle. The veins returning the blood are the inferior dental, the infra-orbital, and certain muscular branches. These veins form a plexus between the ext pterygoid and the temporal muscles, preparatory to uniting n maxillary vein, The veins forming the plexus internal maxillary artery, while the intern internal maxillary artery itself. The it in the parotid gland to form the ex THE FACE. 19 plexus have no valves. They communicate in front with the facial vein by the deep facial ; at the base of the skull and with the cavernous sinus in the dura mater by the emissary veins, ‘The Supra-orbital Nerve. The supra-orbital nerve is a branch of the ophthalmic division of the trifacial ; it passes through the supra-orbital foramen in the frontal bone, and supplies the skin of the eyelid and forehead with sensation ; it communicates with the facial nerve, and is accompanied by the vessels of like name. The Supra-orbital Artery is a branch of the ophthalmic ; it traverses the supra- orbital foramen, and anastomoses with the superficial temporal artery. Fie. 3, Internal maxillary artery. (Gents after TEstUT.) The Parotid is the largest salivary gland ; it weighs about one ounce, and is covered by a very dense fascia, which is continuous above with the temporal, in front with the masseteric, and below with the cervical fascia. Liarratio: Superiorly, the zygomatic arch ; inferiorly, the mastomandib- e ; anteriorly, the mid-line of the masseter ; posteriorly, the ear and sterno- mastoid muscle ; in(ernal/y, the styloid process. Supra he anterior surface of the gland embraces the mandible ; the # surface is lobulated and covered by the parotid fascia, superficial fascia, and j the inner surface embraces the styloid process of the temporal hone ; J carotid artery and the internal jugular vein are in close relation 20 A MANUAL OF DISSECTION. ConTENTs. 1. The facial nerve, whose temporofacial und cervicofacial divi- sions give off the pes anserinus. 2. The auriculotemporal nerve, a branch of the superior maxillary. 3. The external jugular vein, formed by a confluence of the posterior division of the temporomaxillary and posterior auricular veins. 4, The external carotid artery, which breaks up into the temporal, internal maxil- lary, transverse facial, and posterior auricular arteries, Tue Broop-suppty is derived from the external carotid, temporal, internal maxillary, posterior auricular, and transverse facial arteries. The veins which accompany the arteries from the parotid gland empty into the external jugular and take the name of the arteries. Nerve-supp.y. 1. Sympathetic, from the carotid plexus. 2. Motor, from the facial. 3. Sensory, from the great auricular and auriculotemporal. 4. Vaso- Fig. 4, 7 ‘The salivary glands. The right half of the body of the mandible has ceen removed. GL. W., gland of Weber. GL. B., gland of Blandin. (Gennisy after TextuT.) dilator, from the ninth nerve, via tympanic, small superficial petrosal, otic gang- lion, third division of fifth, and anricnlotemporal. Srensoy’s Duct is the excretory conduit of the parotid gland. It lies ina line extending from the lower part of the lobule of the ear to the middle of the upper lip. It is about a quarter of an inch in diameter, and in its course crosses the masseter muscle, perforates the buccinator, and opens into the vesti- bule of the mouth opposite the second upper molar tooth, one and one-half inches long, and the distal one-half im mucous membrane and the buccinator muscle, the mueou valve. The duct may receive a tributary from the 4 small, detached portion of the parotid gland on the” gland is separated from the submaxillary by the: THE FACE, 21 THE MUSCLES OF FACIAL EXPRESSION. The Orbicularis Oris surrounds the mouth. It has two series of fibres: 1. An inner, which surrounds the mouth by continuity. 2. An outer, which decussates at the angles and intermingles with fibres of all muscles, above and below, that antagonize it. The continuous fibres constitute the labial, the decussating fibres ‘The labial fibres are pale, thin, and not attached are thinner, broader, attached to the alveolar and haye muscles inserted into them. The muscle is closely connected, in and to the mucous membrane, The labial glands and coronary cous membrane and the muscle, Attachments, cartilage 22 A MANUAL OF DISSECTION. at ike nasal s*ptum, incisive fossa of the maxilla, incisive fossa of the man- ible. The Zygomaticus Major. Origin: The malar bone. Insertion: The angle of mouth. The facial artery and vein are beneath, while Stenson’s duct passes under this muscle. The Zygomaticus Minor. Origin: The malar bone. Insertion: The upper lip. It may be incorporated with the zygomaticus major, and it requires care to distin- guish the two muscles. The Levator Labii Superioris. Origin: The superior maxillary bone above the infra-orbital foramen. Insertion: The facial part of the orbicularis oris, Beneath the muscle is the infra-orbital plexus, formed by the fifth and seventh nerves, and also the anastomoses of the infra-orbital and facial arteries. Action, elevates and protrudes the lip. The Levator Anguli Oris. Origin: The canine fossa. Insertion: The facial part of the orbicularis oris. Between it and the preceding muscle is the infra- orbital plexus, The Levator Labii Superioris Al que Nasi. Origin: The nasal process of the superior maxillary bone. Insertions: 1. The nasal cartilage of the ala of the nose, 2. Facial part of the orbicularis oris, The Levator Menti, or Levator Labii Inferioris, Origin: The incisive fossa. Insertion: The facial part of the orbicularis oris and skin of the chin, The Depressor Labii Inferioris. Origin: ‘The oblique line of the mandible, below and internal to the mental foramen. Insertion: The facial part of the orbicularis oris. The muscle is quadrate, hence called quadratus menti. The outer and lower part of the muscle is covered by the depressor anguli oris, Action, draws the lip downward and ontward. The Depressor Anguli Oris. Origin: The external oblique line below the cuspid, bicuspid, and first molar teeth. Insertion: The corner of the mouth. The Risorius. Origin: The masseter fascia. Insertion: The angle of the mouth. The muscle is horizontal, varies iu size and shape, and draws the angle back. Morphologically, it is a divorced part of the platysma. The Platysma Myoides has (1) a facial part ; (2). cervical part. The facial part covers the facial vessels and supramandibular branch of the facial nerve. The muscle arises from the pectoral and deltoid fascise, and is inserted into a part of the orbicularis oris. This muscle depresses the mandible. The Orbicularis Palpebrarum surrounds the base of the orbit and covers the eyelids. The interval between the lids is the palpebral fissure. ‘The extremes of the fissure are the outer and inner canthi. ‘The muscle consists of two parts: 1. An inner, that covers the lids, called the palpebral portion. The fibres of this are pale and thin, and not completely under control of the will. 2. An outer part, spread over the margins of the orbit. The fibres of this part are thicker, voluntary, and mingle with the occipitofrontalis, corrugator supercilii, levator labii supe- rioris ale que nasi, levator labii snperioris, and zygomaticus minor. The muscle has the following attachments: 1. The nasal process of the maxillary bone. 2. The internal angular process of the frontal bone. 3. The lower margin of the orbit. 4, The tendo oculi. The Tendo Oculi, At the inner angle of the eye is a thin cord, one-sixth of an inch long. It arises from the nasal process of the superior maxilla, in front of the lacrymal groove. The tendon divides into two parts. One is inserted into the upper lid ; the other into the lower A part of the tendon is attached to the lacrymal sac and margins of the lacrymal groove, in which the sac rests. The tendo oculi aids indirectly the flow of tears into the lacrymal sac. The Tensor Tarsi is a deep part of the orbicularis palpebrarum, specialized for drawing the eyelids and lacrymal canals into a position most favorable for receiv- ing the tears. The muscle arises from the crest of the Incrvmal bone, passes across the lacrymal sac, and divides into two portions, which are inserted into the upper and lower tarsal curtilages. THE FACE. 23 The Corrugator Supercilii, Origin: The inner end of the superciliary ridge. Insertion: The under surface of orbicularis palpebrarum. This muscle produces vertical wrinkles of the forehead by drawing the eyebrows downward and inward. The Levator Palpebre arises from the lesser wing of the sphenoid, above and in front of the optic foramen, and is inserted into the tarsal plate of the upper lid. The Pyramidalis Nasi arises from the occipitofrontalis, and is inserted, with the compressor nasi, into the fibrocartilage of the ala of the nose. It produces transverse wrinkles on the bridge of the nose by drawing the eyebrows down. The Occipitofrontalis consists of (1) an anterior belly, (2) an intermediary aponeurosis, (3) a posterior belly. The posterior belly arises from the outer two-thirds of the superior curved line of the occipital and mastoid process of the temporal bones. The frontal part is very thin. The internal fibres are continuous with the pyramidalis nasi ; the middle and outer fibres are blended with the corru- gator supercilii_ and orbicularis palpebrarum. The.two bellies are united by an aponeurosis. The muscle raises the eyebrows. The Attrahens Aurem. Origin: The aponeurosis of the occipitofrontalis. In- sertion: The helix. The retrahens aurem arises from the mastoid and is inserted into the concha. The attollens aurem arises from the aponeurosis of the occipito- frontalis, and is inserted into the pinna. In man these muscles are rudimentary.’ (See Chapter VII., External Ear) The Compressor Naris arises from the canine fossa. It is inserted into the dorsum of the nose, joining here its fellow of the opposite side, The muscle is triangu- lar. Its origin is concealed by the levator labii superioris ale que nasi. The Compressor Narium Minor arises from the fibrocartilage of the nose,