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 199 A N A T O M Y. fkin of the large eminence in the palm of the hand, beULNARIS EXTERNUS. tween the carpus and the little finger; its fibres adhering fkin, and being in fome meafure interwoven with This is a long mufcle lying on the outfide of the to themembrana adipofa. fore-arm, fkihy toward the os humeri, and tendinous to- theThefe fibres are fixed along the edge of the aponeuroward the carpus. from the large ligament of the carpus toIt is fixed above to the external condyle of the os hu- fiswardpalmaris, the little finger; and they run in for fome fpace on meri, being there united to the anconaeus minor, to the plane of the aponeurofis, hut without any connexion annular ligament of the head of the radius, and to the the the bones of the metacarpus. Near the aponeurofis, upper half of the external angle of the ulna. From with thefe fibres are more or lefs tendinous, and fome of them thence it advances, and forms a tendon, which palfes often crofs each other. through the external notch at the lower extremity of this bone, on one fide of the ftyloid apophyfis. METACARPIUS. The tendon, having afterward pafied under a particular ligament fituated near the os cuneiforme of the car- This is a very fmall flefhy mufcle, fituated obliquely pus, is inferted in the outfide of the bafis of the fourth between the large internal annular or tranfverfe ligament metacarpal bone, fending fome tendinous filaments to the of the carpus, and the whole infide of the fourth metabafis of the little finger. carpal bone. fixed by a fmall fhort tendon to the os orbiculare, Radialis Externus, Primus Sc Secundus. andIttois the neighbouring part of the large ligament of the These are two mufcles clofely united together, lying From thence its fibres run more or lefs obliquealong the external angle of the radius, between the os lycarpus. toward the of the fourth metacarpal bone, in humeri and the carpus, being fleflry near the former, and the outer edgeinfide of which they are inferted. The fibres tendinous near the latter. of this mufcle are of unequal lengths, and extend all the The firft is inferted above, in the crifta of the exterto the articulation of the firft phalanx of the little nal condyle of the os humeri, below the infertion of the way finger with the fourth metacarpal bone, but they have no fupinator longus. The fecond is inferted in the fame manner of relation to that finger. condyle below the infertion of the firft; and in the neighbouring articular ligament. From thence the two Uses of the Mufcles which move the Carpus on the flelhy bodies run down very clofe together ; and having Fore-arm. reached the middle of the outfide of the radius, each of them terminates in a long tendon. the ulnarus internus a£ls alone, or as the prinThe two tendons accompany each other to the extre- cipalWheh mover, it brings the obliquely toward the inmity of the radius; and, having paffed under a particu- ternal condyle, and towardhand the olecranum, though with lar annular ligament, they are divided as it were into difficulty. two cornua ; from whence the ancients, who looked up- When it a<fts together with the radialis internus, it on them as one mufcle, gave it the name of bicornis. turns the hand equally towards the two extremities of One of thefe tendons is inferted anteriorly in the bafis bones of the fore-arm ; and thereby moves not only of the firft metacarpal bone, the other nearly in the fame the the carpus in general on the fore-arm, but alfo the feplace of the fecond bone. cond row of the carpus on the firft, and the metacarpal on the fecond. Ulnaris Graciejs, vulgo Palmaris Longus. bones When it adts with the ulnaris externus, it turns the edge of the hand toward the olecranum. This is a fmall mufcle, lying between the os humeri outer When the ulnarus externus adts with the ulnaris inand the carpus, on the infide of the fore-arm ; its body ternus, it turns the outer edge of the hand toward the being fmall and flender, its tendon very long and flat. olecranum, already faid. It is fixed by its flefhy portion, in the fmall crifta With theasradiales it turns the back of the of the inner condyle of the os humeri, fometimes clofe- hand toward the outerexterni, condyle. ; ly united to the ulnaris internus. From thence it runs this mufcle afls alone, it brings the outer edge down flefhy for fome fpace, turning a little obliquely of When the hand obliquely toward the olecranum and the extowards the middle of the fore-arm, and ends in a long, ternal condyle at the fame time. Barrow, thin tendon. the radialis externus, the internus carries the inThis tendon pafles down the middle of the fore-arm, nerWith edge of the hand, or that next the thumb, toward over all the other mufcles to which it flightly adheres, and the extremity radius, and toward the fold made advancing over the large internal annular or tranfverfe liga- by the ulna andofosthehumeri. ment of the carpus, is inferted in the furfaoe thereof, fend- Alone, it moves that-part of the hand which is next ing off" fome radiated filaments to the aponeurofis palmaris. the thumb obliquely, toward the internal angle of the. radius. PALMARIS CUTANEUS.The radialis externus, together with the" radialis inThis mufcle is afmall thin plane of flefhy fibres, fitu- ternus, turns the inner edge of the hand dire&ly toward ated tranfverfely, or more or lefs obliquely, under the the ftyloid apophyfis of the radius. Witht

Parc II.