The Dublin dissector or manual of anatomy. Comprising a description of the bones, muscles, vessels, nerves, and viscera ...

Chapter I

ANATOMY. OF THE EXTERNAL PARTS OF THE HEAD AND FACE, PAGE.

EXTERNAL PARTS OF HEAD, . . SS bie.

General remarks on muscles of head, ain of, .i« or sg ne Occipito-frontalis, . . F F ‘ : ib.

Epicranial aponeurosis, . : . ast ib, Structure, pathology, &e. of scalp, * h 3 External muséles ofear, . . : . saa EXTERNAL PARTS OF FACE, : ‘ : - 9 Division of muscles of, . d : : Pee Orbicularis palpebrarum, . e . . me i Physiology, &c. of do. . . ye ee ee) S Tensor tarsi, or Horner’s muscle, _. 7 «ib. Mascles of the nose, lips, &c. “ . : > 9 Buccinator muscle, : eat 4 + aban ty OE sey ia Division of glands in gente : : A 25 28 Peculiarities of salivary giants - F 2 - 14 Parotid gland, . , . . A - 15 Steno’s duct, ; “ M - 16 Pathology of parotid slaid! : , ‘ - 18 Masseter, temporal, and pterygoid muscles, : - 19 Temporal aponeurosis; : . : , - 20 Motion of lower jaw, : . : $ - 24 Vessels and nerves of fase, « | . : ; ~ 25 CHAPTER IJ.

ANATOMY OF: THE NECK.

General remarks on the muscles of the neck, a no 28

Platysma myoides, and cervical fascia, ‘ . « ib.

iV CONTENTS.

PAGE.

Sterno-cleido-mastoid muscle, i : ° ot Division of neck into triangular regions, . 32 Sterno-hyoid, thyroid, and omo-byoid muscles, 33 Thyroid body, : ; . , . 34 Physiology and pathology of, : . . - 35 Digastric muscle, . . : - 5 36 Sub- maxillary gland, : : : 37 Whartonian duct, . °! - . ib.

Pathology of sub- “maxillary g gland, ; . 38 Mylo-hyoid and genio-hyoid muscles, 4 . Pa i Sublingual gland, . : ‘ 39 Hyo and genio-hyo-glossi dinshleet sh ib. Styloid muscles, . : A 40 Vessels and nerves of neck, : ; 41 MouTH, . : ‘ : : ‘ 46 Tongue, : : : é : AT Pharynx, constrictors of ; opens in, ° : 48 Palate, arches of ; peetey i : x 52 Levator palati, ea: palati, palato-glossus, ke: 53 Tonsils or amygdala, : 54 Pathology of soft palate, tonsils, io, ib. (Esophagus, A : 4 c 35 Pathology of pharynx and oesophagus, | ib. LARYNX, cartilages, muscles, &c. &e , - 96 Vessels and nerves of lara Nx, :- . ° 61 _ Pathology of larynx and trachea, . a9 O24 Deep muscles of neck ; longus colli, &c. = ib.

CHAPTER IIT.

ANATOMY OF THE THORAX.

Muscles on anterior and lateral parts of thorax, G4 Mammary gland, . : . . - G65 Pathology of, . . 6 ° é(Z ib.

Pectoralis major, &c. &c. : : - 66 Serratus magnus, ° 68 _ Intercostal muscles, : 4 : . 69 Levatores eostarum, dunt sterni, , aTib. ‘ AXILLA, ° . ° ° ° 2iTO Cavity. OF THE THORAX, . : : - 72 ‘Mode of opening thorax, : : wi 7S ‘Anterior mediastinum, ; : oath, Pipers ° : Pe : 0 te Ligainentam latum boteitate: SS la Oe . Mey 3 Posterior mediastinum, vena azygos; thoracic duct, &c. &c. 76 Lunes, ~. . = : ats Pathology of jung and pleare, . . . - 80

CONTENTS. Vv

Pericardium : , : ‘ ; . $l

Pathology of cue HY am . : - 83 HEART, . * ° % P i Be | Pulmonary artery, ; : OD TROTa . 87 Ductus arteriosus, : ; : : a ED, Aorta, . . 5 : : = . 89

Pathology of heart, . s . . oi OD

Parts passing through upper orifice of thorax, . ood Trachea, . . ° ° : : too EE Bronchial glands. : ‘ ‘ . syu92

CHAPTER IV.

MUSCLES ON THE POSTERIOR PART OF THE TRUNK.

Muscles of the back ; Jigamentum nuchz, lumbar fascia, . \9a Trapezius, : ; : . f » 95 Latissimus dorsi, . : A ‘ : - 96 Rhomboid, levator anguli scapule, . | Ms filial . I Serrati postici, . : . P . 28 Splenius, . ; 4 : 7 . 99

Sacro-lumbalis, longissimus dorsi, spinalis ania; cervicalis descendens, &c. &c. . mare ae, 6 T Recti and obliqui capitis postici, . x . . 103

CHAPTER V.

ANATOMY OF THE UPPER EXTREMITY.

Fascia and superficial veins of the arm, . - 105 Deltoid muscle, M 4 ‘ P : . 106 Supra and infra-spinatus, and teres minor muscles, . ~ 107 Sub-scapular muscle, : . - 109

Remarks on Capsular muscles of the shouldet joint, Be al De Coraco-brachialis muscle, . . . . eL41 Biceps, , . : . : : Pers A Brachialis anticus, or externus, ‘ ; .. 113 Triceps, . . F ‘ ‘ «Tbs Vessels and nerves of the arm, . Rae ta . 115 Forearm and hand, ° . » 11% Cutaneous veins, basilie, cephalic, mediad’ ri A . ib. Fascia of forearm, : : > 4 due ghite Palmar fascia, ; : ; : , ‘out 1S Palmaris brevis muscle, . . ei;

Division of muscles of forearm into pronators and Bokors, - 119 Supinators and extensors, . : : : - 124 Muscles of the hand, ‘ : . - 129

Vessels and nerves of the forearm and hand, : . » 432 a2 vi CONTENTS,

CHAPTER VI.

ANATOMY OF THE ABDOMEN AND PELVIS.

Superficial fascia of the abdomen,

Obliquus externus,

Linea alba, linea semmiladatis: lineze tranaveren” External inguinal ring iatevanitxaier fascia, Poupart’s or Vainpinst ligament,

Gimbernant’s ligament, . ° ° .

Triangular ligament or fascia, tA’ .

Obliquus iitehive or ascendens, . ‘ Cremaster muscle, i ; A : Transversalis, i 5 : 5 .

Rectus and pyramidal muscles, : : .

Transversalis fascia, p : ° me: Spermatic or inguinal canal, ar , ° HERNIA, ‘ : y : .

Oblique inguinal, : : . .

Direct or ventro-inguinal, Femoral or crural,

Inguinal glands, . Ay on ‘ :

Saphena vein, .

Fascia lata, . 4 : ‘

Fascia iliaca, ‘ ° ‘

Femoral or crural ring, : ° :

Fascia propria, . :

Measurements of parts eieaved | in hennie, : :

Regions of abdomen, ‘ . ° :

Peritoneum, °

Omenta, mesocolons, &c. 0! ‘ Division of viscera of abdomen, .

Stomach, : A ‘ ‘ .

Glandule Branneri, : ‘A rs

Duodenum, jejunum, ilium,

Large intestine, division of, &c. °

Cexcum or caput coli, ilio-colic valves, Colon and rectum,

Structure of intestinal a : A ; Glandule agetegate or Peyeri, .

Pathology of peritonzam and abdominal viscera, _. Liv eT, ® e

Pathology of .

Gall bladder, °

Pathology of , Spleen, ; :

Pathology of

CONTENTS, Vil ; PAGE. _ Pancreas, - : 4 ‘ . 183 Pathology of, . { ° : : . 184 Vessels and nerves of the abdomen, . : . - Hb. Kidneys." « - : : : 189 Ureter, -+ : i j 190 Renal capsule or pts a -renal or Pialiaey body, ‘ . 191 Pathology of ate . ° ° . - 192 Bladder, . ° 5 4 . - 211 Pathology of 217 Urethra, . . Sa he FoR . 229 Diaphragm, : - 193 Muscles which siteist in respiration, 196 Quadratus lumborum, psoz, and iliac maseles, . 197 PERINEUM IN THE MALE, . . 199 Sphincter ani, superficial fascia, : : - 200 Erector or compressor penis, . - 202 Accelerator urine or ejacalator sunate: &e. dau! : 203. Triangular ligament of urethra, i F ‘ . 205 Cowper’s, or the anti-prostatic glands, : . «10s Levator ani muscle, - : : ‘ 206 Compressores urethrx,-or Wilson’s muscles, : ° 204, Surgical anatomy of parts concerned in lithotomy, 208 Pubic. ligament, : . 209 Coccygeas muscle, : ‘ Ae Triangular space on fundus of bidet . 210 Pelvic portion of peritoneum, i - 211 Urinary bladder, : : ib.

Pathology of, i . é 217 Pelvic, obturator, and vesical en seeae: ; Spree Ligaments of the bladder, : . fs ib. Gdits of the bladder, ©. : ¥ : - 215 ORGANS OF GENERATION IN THE MALE, 218 Scrotum, - 5 219 Dartos, superficial fascia, ie Tunica vaginalis, albuginea, : - - 220 Testicle, , i : : : aged hl Epididymis, p : : ‘ ‘ ae | Vas deferens, at 3 4 ‘ ‘222 Spermatic cord, o eae Vesicniz seminales, P , r : . 225 Prostate gland, f . . ib.

Penis, : ‘ ‘ - eee a a Urethra, . : 4 tiaeo Method of iene the penis and corpus spongiosum urethre, : u : 230 Pathology of testicle : | 5 . 232 _ Pathology of vesicula seminales sud prostate ghar: » 233 vill CONTENTS.

_ CHAPTER VIL.

ORGANS OF GENERATION IN THE FEMALE.

Vagina, uterus, &c. &&. Sy 4 , : Fallopian tubes and ovaries, ; a Pathology of female’ “organs of generation, o

CHAPTER VIUI.

ANATOMY OF THE INFERIOR EXTREMITY.

Fascia lata, ; 7 Muscles on the forepart and lee of the high; : Tensor vagine femoris, sartorius , triceps adductor, &e. &e. Vessels and nerves of the thigh, . ‘ : Mascles on the posterior part of the thigh, . ; Glutzus maximus, medius, &c. &c. : 7 Pyriformis, obturator internus, externus, gemelli, &c. &c. Gluteal and sciatic vessels, Sc. 3 : . Sciatic nerve, &c. . “ ; Hamstring muscles, : , : : Popliteal space, . ‘ : a : Leg ; fascia, sub-cutaneous veins and nerves,

Plantar fascia, 8 A ; - Muscles on the anterior and external part of the leg, Anterior tibial vessels and nerves, . ’ d Muscles on the back of the leg, ‘ 4 ~ Muscles of the foot, . ‘ ¢ .

Posterior tibial vessels and nerves, . Ate :

Part II. Of The Nervous: System

CHAPTER TI.

- 240 . 243 e ib.

BRAIN, MEDULLA OBLONGATA, AND ORIGIN OF THE

CEREBRAL NERVES. »

BRAIN, | F d ‘ ‘ e Dura mater, ; . ‘ ‘ ‘ Sinuses, . ‘ . ‘ . .

- 286 - 287 « 290

CONTENTS.

Arachnoid meee pia mater, ° : : Cerebrum, ° 7 4 ° ° Ventricles, 4 ° on Hf ° Cerebellum, ; ‘ ah F .

MEDULLA OBLONGATA, - . Bs .

ORIGIN OF THE CEREBRAL NERVES, e °

CHAPTER IL.

ANATOMY OF THE MEDULLA SPINALIS, ETC.)

Origin of the spinal nerves, ; 3 Dissection of the brain from below, ; é Structure of the cerebellum, ; a e Structure of the cerebrum, ait é Vessels of the brain, ; ie , .

Pathology of the brain and its membranes, ’

CHAPTER ‘III.

316 317 318 319 320

. 321

DISSECTION OF THE CEREBRAL, SPINAL AND GANGLIONIC

NERVES.

Olfactory, a ; . : Optic, . 5 ° o° Third and fourth, ae : ° .

Ophthalmic nerve, ° : : : Lachrymal, frontal, and nasal nerves, “ Sixth or abducens nerye, ‘ si . : Ophthalmic or lenticular ganglion, . : .

Offices of orbital nerves, . a : Superior maxillary nerve, : : : Meckel’s ganglion, . : : Palatine, spheno-palatine, naso-palatine, or nerve of

Naso-palatine ganglion, : : . .

Vidian nerve, corda tympani, submaxillary ganglion, Inferior maxillary nerye . wk . : Inferior dental and gustatory nerves, .

_ Facial nerve or portio dura, ats : . Auditory nerve or portio mollis, ‘ . . Glosso-pharyngeal nerye, . . : : Pneumo-gastric nerve, eis : . : Pharyngeal plexus, be oe : : Laryngeal nerves . . . : . : Pulmonic plexuses, . : : : Cisophageal plexus or plexus gulez, : 4

Spinal accessory nerve, ea [ 3 §

. 340 p.< CONTENTS.

‘Lingual nerve, .. : . : SPINAL NERVES, »

Sub-occipital nerve, . we .

Cervical plexus, .~ , a ; Phrénic or internal respiratory nerve, . ‘External respiratory nerve, . ° Brachial plexus, . alert : Thoracic and scapular branches, . : Internal cutaneous, external cutaneous, 4

Median or brachial, ulnar, musculo-spiral, &c. Dorsal nerves, ps : .

‘Nerves of Wrisberg, . ‘ Lumbar nerves and plexus, ° : Inguino-cutaneons, anterior crural nerves, . Obturator, glutzal, communicating, &e., Sacral nerves.and plexus, . -

Lesser sciatic, inferior gluteal, pudic nerves, &c.,

Great sciatic or posterior crural nerve, . SYMPATHETIC NERVES, F d Cervical ganglions, ° ‘ .

Cavernous or carotid ganglion, ‘ .

Cardiac nerves, s . . F Cardiac plexus, cardiac ganglion, . . Thoracic ganglions, . . .

Splanchnic neryes, ° . : Solar plexus, . . . : Lumbar ganglions, ‘ ° e Sacral or pelvic ganglions, °

Ganglion impar, .

CHAPTER IV.

ORGANS OF SENSE.

Nose, : ‘ ; ° Taste, . 4 Y ° Ear, . a 4 é Eustachian tube, ‘ : : Bones of the ear, . . ° Muscles of the ear, : - A Labyrinth, * . ‘ : . Eye, : : 4 : i Muscles of the orbit, ; < .

Lachrymal apparatus, , . .

Eyelids, . : = .

Horner’s muscle, . L Z ° Globe of the eye, : : : Skin, or the organof touch, ° .

Cellular membrane, . , °

. 364

366 367 368

CONTENTS. xi

Part III. Anatomy Of The Vascular System

PAGE.

ARTERIAL SYSTEM, ‘ ‘ e . 386.

Aorta, 5 " ‘ A £ &.abs Coronary arteries, . : . . - 387 Arteria innominata, . 3 ‘ ah oA De Carotid arteries, . A , ‘ r «| ab.

External carotid, : ‘ . . 388 Superior thyroid, lingual, and isbiel: : “ arabe Muscular, occipital, posterior, auricular, and pharyngeal, . 389 Trausverse facial, temporal, and internal maxillary, . . 390 Internal carotid, : . . 391

Ophthalmic stl cerebral duidies, ‘ . é mars | Subclavian arteries, * ‘ . 393

Vertebral, basilar, thyroid axis, internal mammary, Se: - ib. Axillary artery, . ; A : : - 395 Brachial artery, . , i : ° . 397 Profunda arteries, &c. x 3 é . ib.

Ulnar artery, ‘ . ‘ : «EDS Radial artery, : : P ‘ . . 399, Thoracic aorta, é - «pidhs Bronchial, oesophageal, and intercostal arteries, ° « ib, Abdominal aorta, . ; é a ghee -« 400) Phrenic arteries, ‘ ‘ : ° ae Cceliac axis, : F EEE a telah Sk . 401 Mesenteric and renal arteries, * ; ° - 402: Spermatic, lumbar and middle sacral arteries, : ~ 403; Internal iliac arteries, " bin : «pid dal Glutzal, obturator, prdic, bo. : . : - 404) External iliac, — 7 Ove : ‘ ‘ « 405°, Femoral artery, : - 406: Profunda artery, ‘ ‘ F by Circumflex arteries, - . - 407 Popliteal artery, ee ye Bears - 408 Anterior tibial artery, : : : : ~. db. Posterior tibial, . : m : ‘ . 409 Peronzeal arteries, Ashe : : ay aie VENOUS SYSTEM, a “3 . ; - 410 Veins of the head, ‘ é x s ib.

External jugular vein, : les aati , ib. Internal jugular vein, , 7 ’ . Alle Veins of the arm, ‘ ‘ » iby Venz innominate, ; . . b r Al2

Vena cava superior,

Xi CONTENTS.

Vena azygos, : . ‘ : : Veins of the leg, .. ° . > : Iliac veins, : : . ° : Vena cava inferior, : : : 4 Vena porte, : : : Heemorrhoidal, mesenteric, ttid pleaic veins, LYMPHATIC SYSTEM, ‘ é : ‘Thoracic duct, Z ea: if § ar Receptaculum chyli, :

Structure of coats in arteries, vtinws and lyhiphatiate Feetal circulation, : : , Umbilical vein, ; ter “i ; .

Ductus venosus, . “ 3 ; Ductus arteriosus, : : ° : Thymus gland, : : : : :

Part IV. Of The Bones

The vertebra, 5 4 i as “

Sternum, . ee : : i a Ribs, Z 7 i ’ : - Thorax, . ; Sacrum, . : 2 : - Ossa coccygis, - ‘ : Ossa innominata, , : : : F llium, , : : : : Ischium, . ; , : : Pubis, : ; F : : ; Acetabulum, ee ; : - Pelvis, i : 5 : ! : Head, : ; e A ~ Frontal bone, 4 : ‘ Parietal, : : 4 “ s Occipital, . .

Temporal, ; : ‘ omer hrs Ethmoid, - ; P 3 Ales ‘Sphenoid, : Sutures, . : { ‘ ‘ ‘ Skull in general, . ; : : Bones ‘of the face, ‘

. Malar bone, : : ‘ ; , Superior maxillary bone, . , . .

Palate bone, ae , : iter 4

CONTENTS. xii

PAGE.

Enferior spongy or turbinated hone, . ‘ ) + 463 Os unguis or lachrymal bone, ; ‘ o 1b Nasal _ bone, . . : 7 464 Yomer, . ‘ q P , ari say Inferior maxillary bone, 4 3 : a - 465 Teeth, 3 A : 4 é - 466 Orbit, i : x ‘ : - 468 Palatine region, H 3 : i i sj hy lbe Temporal fossa, . . - « . - 469 Zygomatic fossa, . ; . ‘ ‘ «ab.

Pterygo-maxillary fossa, . ° : . xia bhi. Femar, : . ls % . ‘ . 470 Patella or rotula, . : < : - 472 Tibia, ; ‘ . ‘ ‘ ° - A473 Fibula, . : : “ . : - ATS Tarsal bones, ° . % ‘ . - 476 Metatarsal, " ‘ 4 f “ « 479 Phalanges, : ; : : 9) pitt baw 480 Clavicle, . ° . 2 . . - ib.

Scapula, . f : ' . ° - 482 Humerus, : i d a yok < - 484 Ulna, “ ; a " ; . 486 Radius, . i 7 . 4 é - 487 Carpal bones, F 3 : 4 ay at - 489 Metacarpal bones, ° : ° ° - 491 Phalanges, . . ° . ° - 492 Sesamoid bones, ‘ _ . ° ‘ « 493

Part V. Of The Joints

Temporo-maxillary articulations, . . ° - 496 Dislocations of the lower jaw, . ‘ : - 498 ‘Articulation of the occiput with the atlas, . : . 499 Articulation of the occiput with the axis, . . - 500 Articulation between the first and second yertebre, . - 501 Common articulation of the vertebra, a : - 003 Inter-vertebral ligaments or fibro-cartilages, . - 904 Articulation between the pelvis and the spine, ; - 506 Ligaments of the pelvis, . : . e - ib. Articulations of the ribs, . ; : : - 508 LIGAMENTS OF THE SUPERIOR EXTREMITIES, - o10 Sterno-clavicular articulation, 5 ‘ 5 - S11 Scapulo-clavicular articulation, . ° . - 512

XIV CONTENTS.

PAGE.

Dislocations of the clavicle, . , : . 513 Ligaments of the scapula, ' A ° eS |S Humero-scapular or shoulder articulation, . ; . 514 Dislocations of the shoulder, s 3 A . 515 Humero-cubital articulation, or the elbow joint, ; . 516 Radio-ulnar articulations, : . : . 518 Dislocations of the bones of the elbow joint, ° tabs Dislocations of the carpal extremities of the radius or ulna, 520 Radio-carpal articulation, or the wrist joint, : . 521 Articulations of the bones of the carpus, - “ . 522 Dislocations of the bones of the carpus, . 524 Articulation between the carpus and metacarpus, ° - ib. Dislocations of the metacarpal bones from the carpus, - ib. Articulation between the metacarpus and the phalanges, - 525 Dislocation of the thumb, . 2 t - . Id. LIGAMENTS OF THE INFERIOR EXTREMITIES, : - 526 Tlio-femoral articulation, or the hip joint, . . 2 4b. Dislocations of the hip, * - : : - 528 Femoro-tibial articulation, or the knee joint, oe - O81 Dislocations of the patella and knee, * . |, 537 Superior tibio-fibular articulation, . . . . 588 Dislocation of the tibio-fibular articulation, ow .° th. Inferior tibio-fibular articulation, ‘ ‘ - 539 Articulation of the ankle, : . ‘ 2 ib. Dislocations, &c. of the ankle, - ‘ : \ . o41 Articulations of the bones of the tarsus, ‘ . . 543 Articulations between -the tarsus and meta-tarsus, &c. 2 O45

Appendix

Directions for making dried preparations of arteries, . - 548 Laennec’s division of the regions of the thorax, A - 550

Directions for opening the head, thorax, and abdomen, *, 552

THE

DUBLIN DISSECTOR.

CHAPTER I.

DISSECTION OF THE EXTERNAL PARTS OF THE HEAD AND FACE.

Section I. External Parts Of The Head

Tus integuments covering the cranium are firm and dense, although when felt they give the sensation of being thin: the cuticle is delicate, but the cutis is very thick, and furnished with many sebaceous follicles; the subjacent cellular membrane contains granulated fat, and the bulbs of the hairs, which afterwards perforate the skin in an oblique direction. The cellular tissue is condensed, having somewhat a ligamentous structure, it ad heres so intimately to the subjacent muscular and tendinous expansion, that the inexperienced student may find some difficulty in. exposing the surface of the latter. Make an incision through the integuments along the median line, from the tuberosity of the occipital bone, as far forwards as the lower part of the forehead, from each extremity of this, make a transverse incision about three inches long ; let the posterior one be parallel to the superior transverse ridge of the occipital bone, and the anterior one parallel, and about half an inch superior to the | B g DUBLIN DISSECTOR.

eyebrow ; cautiously dissect off the integuments from the subjacent muscular and tendinous expansion, which is the occipito-frontalis. This muscle, like most of the superficial muscles of the face, is closely attached to the skin, which circumstance, added to the paleness and smallness of their fibres, renders their dissection somewhat difficult and tedious. Most of the superficial muscles of the head and ‘face, during life, assist some of the organs of sense, and contribute to produce ‘certain changes in the countenance, indicative of character or passion, and expressive of many diseases, tetanus, peritonitis, &c. In point of function, they may be considered as belonging to the class of mixed muscles, that is, they are in part voluntary and in part involuntary: with the exception of the aponeurosis of the occipito-frontalis, the tendon of the orbicularis palpebrarum, and that of the corrugator supercilii, there is no perfect tendinous structure in the other muscles of this class.

The superficial museles of the head are divided into those of the cranium and face. Those of the eranium are the occipito-frontalis, and the three common muscles of the ear, to these some add the corrugatores superciliorum ; these, however, I prefer placing among the muscles of the face.

Occipito-Fronvatis is the only muscle which properly belongs to the scalp ; it is a thin, broad, digastric, or rather quadriceps muscle, fleshy ‘at each extremity, aponeurotic in’ the centre. If arises on each side by tendinous and fleshy fibres, from the two external thirds of the superior transverse ridge of the -oecipital bone, and from thé external and posterior part of the mastoid process; the fibres on each side ascend from behind forwards and from without inwards, and soon terminate in one thin and broad tendon, which extends over the upper~and lateral parts of the cranum.—This epicraneal aponeurosis having arrived opposite the coronal suture, ends’ in two fleshy portions, broader and ‘thicker than the posterior extremities of the muscle; these anterior portions, which are thicker externally than internally, descend over the frontal bone, and are inserted, fleshy on each side, into the integument of the eyebrow, mixing with the fibres of the corrugator supercilu and orbicularis palpebrarum ‘muscles: a small fleshy slip is often continued down along the nasal bones, and is attached to the angular process of the os frontis, and inferiorly to the nasal bones or cartilages: this slip is described by some as a distinct muscle, under the name of pyramidalis nasi, or fronto-nasalis. Use. The occipito-frontalis muscle can raise the eyebrows and integument of the forehead into transverse wrinkles, draw the eyebrows alittle outwards, and make tense the skin of the upper eyelids, and thus expose the eyeball, as in staring, it can also pull the scalp backwards; but if the eyebrows be depressed and fixed, this muscle can then (particularly in some persons) draw the scalp downwards and forwards. ‘This muscle is very closely connected to the scalp, particularly in front, but loosely to the cranium, it can thus move easily on {he latter, carrying with it the former, which it also serves to support in apposition with the cranium, so as to prevent the skin slipping or yielding when any weight is pressed against the head.

Its origin is connected with the sterno-mastoid, the trapezius, and splenius muscles, and its insertion with those of the eyebrows. Some describe the occipito-frontalis, not as one, but as four distinct muscles, two on each side, under the names of the occipital and frontal muscles of each side, and consider the cranial aponeurosis as their common insertion. Several vessels and nerves perforate this muscle, and ramify on its surface and in the integument, viz. anteriorly the supra-orbital branches of the ophthalmic nerve and artery; laterally, the temporal and posterior auris arteries with branches of the portio dura and inferior maxillary nerves, and posteriorly, the occipital arteries spread their branches upwards and forwards, accompanied by the occipital nerves, branches of the cervical plexus. It covers from behind forwards, the occipital, temporal, parietal, and frontal bones, also the upper portion of each temporal aponeurosis, the corrugator supercilii muscle, and the supra-orbital nerves and vessels. The cranial or epicranial aponeurosis is composed of tendinous fibres which are distinct, glistening, and parallel behind, but anteriorly become weak, greyish, and interlaced like cellular tissue, and froqueuay deficient in spots.

The integuments in this region are highly Gvadnired, being supplied with numerous nerves and vessels, these are derived from different and distant sources, and aré chiefly destined to nourish the hair bulbs in the cellular tissue ; in the line of the sutures*they have frequent inosculations with the vessels of the diploe, and of the dura mater. This high organization of the scalp is not only of anatomical but of practical importance, as it serves to explain many of the pathological phenomena which are of ordinary occurrence in this region; thus, it is fre- .

quently the seat of encysted tumours, horny growths, &c., these appear to arise in the sebaceous follicles, the ducts of which have become obstructed from irritation or injury ; a yitiated secretion then accumulates in the sac, which sometimes becomes circularly enlarged, and at others the contents slowly escaping from the ducts, and hardening, assume horny and various other appearances. The scalp is a common seat of erysipelas, both idiopathic and symptomatic. Injuries of it are of very frequent occurrence, and are more serious than those of the same extent in other situations. Incised wounds bleed more freely ; punctured wounds are very frequently followed by high inflammatory symptoms, local and general, in consequence of matter being confined under the tense epicranial aponeurosis, which, in such cases, will require free division. The compact density of the cellular tissue explains the hard rim which surrounds the ecchymosis, the effect of injury. .

In the foetus the scalp is very thin, and the aponeurosis is loosely attached to the cranium by reticular membrane}; this, and not the subcutaneous cellular tissue is the seat of those large ecchymoses so commonly seen after parturition, and which in general are quickly removed by the absorbent system.

The common muscles of the ear are three in number, viz. superior, anterior, and posterior auris :

SUPERIOR Auris, or ATTOLLENS AUREM, is a small, thin, triangular muscle, situated on the temple, and above the ear, arising broad and tendinous from the cranial aponeurosis, where it covers the temporal fascia on the side of the cranium, just above the external ear; the fibres descend converging, become fleshy, and are inserted into the upper and anterior part of the cartilage of the ear :—use, to raise the cartilage, and deepen the meatus of the ear, also to make tense the epicranial fascia. This

Actgi”? Chips. iit sani ee ae muscle is between the skin and temporal fascia, its anterior edge is confounded with the following muscle.

ANTERIOR AuvrRIs, or ATTRAHENS AUREM, Is connected with the last, is of the same form, but smaller, and often indistinct ; it avzses from the posterior part of the zygomatic process, and from the cranial aponeurosis, passes backwards and downwards, and is inserted into the anterior part of the helix; wse, to draw the external ear forwards and upwards. ‘This muscle is superficial, and hes on the temporal fascia, vessels, and nerves, its lower edge is lost. in the cellular tissue.

Posterior Auris, or RETRAHENS AUREM, often consists of two or three distinct fasciculi, it is the strongest of these auricular muscles; it has no connexion to the epicranial fascia, but arises from the mastoid process above the sterno-mastoid muscle, passes forwards, and is inserted into the back part of the concha; use, to enlarge the meatus of the ear and direct it backwards. This muscle is covered only by the skin, it lies upon the temporal bone.

In addition to these muscles, which move the external ear, there are several small muscles attached to different parts of the cartilages, which serve to alter their form, and expand their cavities; these muscles, as also those in the tympanum, shall be described hereafter in the dissection of the organ of hearing.*

Section II. Dissection Of The External Parts Of The Face

THE muscles of the face require careful dissection ; they are delicate, and often very pale; they may be classed into the superficial and deep: the former into those of