| XXX | (183) | XXX |
183 Parti. A N A T O M Y. one. From the backmoft prominent part of this above which, a rough protuberance gives infertion to the great trochanter, a rough ridge runs "backwards and tendon of the triceps. The condyles, both on the outer and inner fide of the knee, are made flat by the mufdownwards, into which the quadratus is inferted. In the deep hollow, at the internal upper fide of this cles palling along them. On the back part of the inridge, the obturator externus is implanted. More in- ternal, a flight depreflion is made by the tendons of the ternally, a conoid procefs, called trochanter minor, rifes, gracilis and fartorius ; and on the external, fuch another for the infertion of the mufculus pfoas and iliacus inter- is formed by the biceps flexor cruris behind which, a nus, and the pedtineus is implanted into a rough hol- deep folia is to be obferved, where the poplitaeus mufcle low below its internal root. The mufcles inferted in- has its origin. From the tubercle immediately before to thefe two procefles being the principal inltruments of this cavity, a Itrong round ligament goes out to the upthe rotatory motion of the thigh, have occafioned the per part of the fibula. Round this lower end of the thigh-bone, large holes are found, into which the liganame of trochanters to the procelfes. The body of the os femoris is convex on the fore-part, ments for the fecurity of the joint are fixedv and bloodand made hollow behind, by the adtion of the mufcles veflels pafs to the internal fubltance of the bone. that move it and the leg, and for the conveniency of fit- The thigh-bone being articulated above with the acetabulum of the ofia innominata, which affords its round ting, without bearing too much on thefe mufcles. The fore-part of the thigh-bone is a little flatted above head a fecure and extenfive play, can be moved to every by the beginning^of the crurseus mufcle, as it is alfo be- fide; but is rellrained in its motion outwards by the high low, by the fame mufcle and the redtus.— Its external brims of the cavity, and by the round ligament; for 0furface is likewife made flat below by the vaftus externus, therwife the head of the -bone would have been frequentwhere it is feparated from the former by an obtufe ridge. ly thru!! out at the breach of the brims on the infide, rThe valtus internus depiefies a little the lower part which allows the thigh to move confiderably inwards. of the internal furface. The pofterior concave furThe body of this bone enjoys little or no rotatory face has a ridge rifing in its middle, commonly called li- motion, though the head moll commonly moves round nea afpera, into which the triceps is inferted, and the its own axis; becaufe the oblique progrefs of the neck Ihort head of the biceps flexor tibiae rifes from it. and head from the bone is fuch, that the rotatory motion At the upper part of it, the medullary veflels enter by a of the head can only bring the body of the bone forfmall hole that runs obliquely upwards.—A little above wards and backwards. The os femoris is articulated which, there is a rough fofia or two, where the tendon below to the tibia and rotula in the manner afterwards to of the glutaeus maximus is fixed. The lower end of be deferibed. the linea afpera divides into two, which defeend towards The nearnefs of the fmall neck to the round head of each fide. The two valli mufcles have part of their > the diigh-bone, and its upper end being covered with very origin from thefe ridges; and the long tendon of the tri- thick mufcles, make greater difficulty in diltinguilhing ceps is fixed to the internal, by means of part of the between a luxation and fra&ure here, than in any other fafeia aponeurotica of the thigh. Near the beginning part of the body. of the internal ridge, there is a difeontinuation of the The Leg is compofed of three bones, tihia, fibula-, ridge, where the crural artery pafles through the apo- and rotula. neurofis. Between thefe two rough lines, the bone Tibia, fo called from its refemblance to an old mulhis made flat by the large blood-yeflels and nerves which cal pipe or flute, is the long, thick, triangular bone, fi pafs upon it; and near the end of each of thefe ridges, tuated at the internal part of the leg, and continued in: a fmall fmooth protuberance may often be remarked, almolt a ftreight line from the thigh-bone. where the two heads of the external gaftrocnemius muf- The upper end of the tibia is large, bulbous, and cle take their rife ; and from the fore-part of the inter- fpongy, and is divided into two cavities by a rough irre,nal tubercle, a ftrong ligament is extended to the infide gular protuberance, which is hollow at its molt prominent part, as well as before and behind. T he anterior of the of the tibia. The lower end of the os femoris is larger than any o- two ligaments that compofe the great crofs one, is inther part of it, and is formed into a great protuberance ferred into the middle cavity, and the depreflion behind on each fide, called its condyles; between which a confi- receives the pollerior ligament.—The two broad cavities derable cavity is found, efpecially at the back-part, in at the tides of this protuberance are not equal; for the which the crural veflels and nerves lie immerfed in fat. internal is oblong and deep, to receive the internal conThe internal condyle is longer than the external.— dyle of the thigh-bone; while the' external is more fuEach of thefe procefles leans to be divided in its plain perficial and rounder, for the external condyle. In fmooth furface. The mark of divifion on the external each of thefe two cavities of a recent fubjeft, a femiluis a notch, and on the internal a fmall protuberance. nar cartilage is placed, which is thick at its convex edge,, The fore-part of this divifion, on which the rotula moves, and becomes gradually thinner towards the concave or is formed like a pulley, the external fide of v/hich is interior edge. The middle of each of thefe cartilages higheft. Behind, there are two oblong large heads, is broad, and the ends of them turn narrower and thinwhofe greatefl: extent is backwards, for the motion of the ner, as they approach the middle protuberance of the titibia; and from the rough cavity between them, but near bia. The thick convex edge of each cartilage is conto the bafe of the internal condyle, the ftrong ligament, nected to the capfular and other ligaments of the articucommonly called the crofs one, has its rife. A little lation, but fo near to their rife from the tibia, that the cartilages
