| XXX | (176) | XXX |
Part I. 176 A N A T o M Y. ridge'gives infertioa to a (hare of the cucullaris mufcle. ftreight: For, above the fpine, it runs obliquely forThe upper furface of the clavicle here is fiat; but the wards to the luperior angle; that here it might not be loy/er is hollow, for lodging the beginning of the muf- too protuberant' backwards, and fo bruife the mufcles and culus fubclavius; and towards its back-part a tubercle teguments: Into the oblique fpace the mufculus patientiae rifes, to which, and a roughnefs near it, the ftrong fhort is inferred. At the root of the fpine, on the backthick ligament connefting this bone to the coracoid pro- part of the bafe, a triangular plain furface is formed, by the preflure of the lower fibres of the trapezius. cefs of the fcapula is fixed. The external end of this bone is horizontally oblong, Below this the edge of the fcapula is fcabrous and rough, fmooth, Hoping at the polterior fide, and tipped in a re- for the infertion of the ferratus major anticus, and rhomcent fubjedt with a cartilage, for its articulation with the boid mufcles. The back-part of the inferior angle is made fmooth by acromion fcapulm. The medullary arteries, having their direction oblique- the latiffimus doth palling over it. This mufcle alfo ally outwards, enter the clavicles by one or more fmall ters the diredHon of the inferior cofta, fome way forwards from this angle: and fo fat it is flatted behind by the opaffages in the middle of their back-part. The triarigular unequal interior end of each clavicle, rigin of the teres major. As the inferior cofta adhas the cartilage above deferibed interpofed betwixt it vances forwards, it is of confiderable thicknefs, is (lightand the irregular cavity of the fternum.—■—The liga- ly hollowed and made fmooth behind by the teres minor, ments, which furround this articulation to fecure it, are while it has a fofla formed into it below by part of the fodhort and ftrong, that little motion can be allowed any fubfcapularis ; and between the two a ridge, with a fmail way; and the ftrong ligament that is ftretched acrofs the depreffion, appears^ where the longus extenfor ciibiti has upper furcula of the fternum, from the pofterior promi- its origin. nent angle of the one clavicle, to the fame place of the The fuperior cofta is very thin; and near its fore-part other clavicle, ferves to keep each of thefe bones more there is a femilunar nitch, from one end of which to firmly in their place. By the nfliftance, however, of the other a ligament is ftretched; and fometimes the the moveable intervening cartilage, the clavicle can, at bone is continued, to form one, or fometimes two holes, this joint, be raifed or deprefted, and moved backwards for the paflage of the fcapular blood-veflels and nerves. and forwards fo much, as that the external end, which ■—-—Immediately behind this femilunar cavity,.-the corais at a great diftance from that axis, enjoys very confpi- co-hyoid mufcle has its rife. From the iritch, to the termination of the foffa for the teres minor, the fcapula cuous motions. The ufes of the clavicles are, to keep the fcapulas, is narrower than any where elfe, and fupports the third and confequently all the fuperior extremities, from falling procefs. This part has the name of cervix. in and forward upon the thorax. The whole dorfum of the fcapula is always faid to be Scapula, or Jhouldcr-blade, is the triangular bone convex; but, by reafon of the raifed edges that furround fituated on the outfide of the ribs, with its longeft fide, it, it is divided into two cavities by the fpine, which is called its bafe, towards the fpinal proceiTes of the verte- ftretched from behind forwards, much nearer to the fubrae, and with the angle at the upper part of this fide perior than to the inferior cofta.. The cavity above about three inches, and the lower angle at a greater di- the fpine is concave where the fupra-fpinatus mufcle is ftance from thefe proceffes.—The back-part of the fca- lodged ; while the furface of this bone below the fpine, pula has nothing but the thin ends of the ferratus anticus on which the infra-fpinatus mufcle is placed, is convex, major, and fubfcapularis mufcles, between it and the except a fofla that runs at the fide of the inferior cofta. ribs: But as this bone advances forwards, its diftance The internal or anterior furface of this bone is hollow, from the ribs increafes.—The upper, or {horteft fide, call- except in the part above the fpine, which is convex. ed thefuperior cojla of the fcapula, is nearly horizontal, and The fubfcapularis mufcle is extended over this furface, parallel with the fecond rib.—The lower fide, which is where it forms feveral ridges and intermediate deprefnamed the inferior cofia, is extended obliquely from the fions, commonly miftaken for prints of the ribs; they third to the eighth rib. The inferior angle of the point out the interftices of the bundles of fibres of which fcapula is very acute; and-the upper one is near to a right the fubfcapularis mufcle is coatpofed. angle. The body of this bone is concave towards the The fpine rifes fmall at the bafe of the fcapula, and ribs, and convex behind, where it has the name of dor~ becomes higher and broader as it advances forwards. fiim. Three procefles are generally reckoned to pro- On the fides it is unequally hollowed and crooked, by ceed from the fcapula. The firft is the. large fpine the aftions of the adjacent mufcles. Its ridge is dithat rifes from its convex furface behind, and divides it vided into two rough flat furfaces: Into the upper one, unequally. The fecond procefs ftands out from the the trapezius mufcle is inferted; and the lower one has fore-part of the upper fide; and, from its imaginary re- part of the deltoid fixed to it. The end of the fpine, called acromion, or top of the fhoulder, is broad and femblance to a crow’s beak, is named coracoides. The third procefs is the whole thick bulbous fore-part of flat, and is fometimes only joined to the fpine by a cartilage. The anterior edge of the acromion is flat, •the bone. After thus naming the feveral conftituent parts of the fmooth, and covered with a cartilage, for its articulation fcapula, the particular defeription will be-more eafily un- with the external end of the clavicle; and it is hollowed derftood. below, to allow a paflage to the infra and fupra-fpinati The bafe, which is tipped with cartilage, .is not all mufcles, and free motion to the os humeri. The
