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 231 Part III. A N A T O M Y. diftributed to the'petioftetifm, and penetrates'the bone, ulnaris externus, extenfor digitorum communis, and to between the mufculus brachiaeus and anconasus internus. the extenfores pollicis indicis and minimi digiti; commuAbout an inch lower, it gives off another branch, nicating with fome branches of the internal interoffeous which having furnifhed ramifications to the anconaeus in- artery. ternus, runs over the inner condyle, and likewife com- Having reached the lower extremity of the ulna, it uwith a branch of the internal interoffeous artery, municates with branches of the arteries of the fore-arm. nites Having got below the middle of the arm, the brachial which, at this place, runs from within outward, and is attery detaches another branch, which runs behind the diftributed, together with it, on the convex fide of the inner condyle, in company with a confiderable nerve; carpus and back of the hand; communicating with the and having paffed over the mufcles inferred in this con- arteria radialis, and with a branch of the cubitalis. dyle, it communicates with that branch of the cubital By thefe communications, this artery forms a fort of irregular arch, from whence branches are detached to artery which encompaffes the fold of the arm. A little lower, it fometimes fends out another branch, the external interoffeous mufcles, and to the external lawhich paffes on the fore-fide of the inner condyle, and teral parts of the fingers. then communicates with a branch which runs up from the' The internal interoffeous artery runs down very dole cubital artery. Thefe three communicating branches are to the ligament, till it reaches below the pronator teres, between which and the pronator quadrates, it perforates termed collateral arteries. The common trunk of the brachial artery having the ligament, and goes to the convex fide of the carpus reached the fold of the arm, runs, together with a vein and back of the hand, where it communicates with the and a nerve, immediately under the aponeurofis of the external interoffeous artery, with the radialis and interbiceps, and paffes under the vena mediana, detaching nal branches of the cubitalis. From the origin of the two interoffese, the cubital arbranches on each fide to the neighbouring mufdes. About a large finger’s breadth beyond the fold of the tery runs down between the perforatus, perforans, and arm, this artery divides into two principal branches, one ulnaris internus, along the ulna, fending branches to the inner or pofferior, named cubitalis; the other outer or neighbouring parts. anterior, named radialis. Afterward, it paffes over the interna! tranfverfe ligaFrom this bifurcation, the brachial artery fends ment of the carpus, by the fide of the cs pififorme, and branches on each fide, to the fupinator longus, pronator having furnilhed the Ikin, palmaris brevis, and metacarteres, fat, and Ikin. It fometimes, though very rarely, pius, it flips under the aponeurofis palmaris, giving off happens, that this artery is divided from its origin into one branch to the hypothenar minimi digiti, and another, two large branches, which run down on the arm, and af- which runs' toward the thumb, between the trindons of terwards on the fore-arm, where they have the names the flexors of the fingers, and the bafes of the metacarof cubitalis and radialis. pal bones, The cubital artery finks-in between the ulna and the It likewife fends off a branch, which, running between upper parts of the pronator teres, perforatus, ulnaris the third and fourth bones of the metacarpus, rriache? gracilis, and radialis internus; then leaving the bone, it to the back of the hand, where it communicates with the runs down between the perforatus and ulnaris intemus, external interofleous artery. Afterwards, having fupall the way to the carpus and great tranfyerfe ligament, plied the interofleous mufcles, it communicates with the and fends out feveral branches. radialis; and they both form an arterial arch, in the holThe firft is a fmall artery, which runs inward to the of the hand. inner condyle, and then turns upward, like a kind of re- lowThis arch fends from its concave fide, towards the fecurrent, to communicate by feveral branches with the cond phalanx of the thumb, a branch for the lateral incollateral arteries of the arm, already mentioned, arid ternal part thereof, ends near the head of th§ particularly with the third. A little lower down, ano- firft metacarpal bone,andbythen a communication with the rar ther fmall branch goes off, which having run upward a dialis, having firft given a branch to the forefide of thf little way, and almoft furrounded the articulation, com- index, and another to the fide of the thumb next the municates with the fecond collateral artery of the arm, former. Thefe communicate, at the ends of the fingers; between the olecranum and inner condyle. with the neighbouring branches, as in the other fingers. Afterwards, the cubital artery having, in its cou'rfe This arch fends likewife fmall twigs to the interofleous between the heads of the ulna and radius, reached the mufcles, to the lumbricales, p. lmaris, and to other neighr interoffeous ligaments, fends off two principal branches, bouring parts; and, laftly, to the integuments. one internal, the other external, called the interoffeous The radial artery begins by detaching a fmall branch, arteries of the fore-arm. which runs upward like a recurrent toward the fold of Tire external artery pierces the ligament about three the arm, and turns backward round the external condyle, fingers breadth below the articulation, and prefently af- communicating with the neighbouring branches from the terwards gives off a branch, which runs up, like a recur- trunk of the brachial rent, toward the external condyle of the os humeri, un- It runs down alongartery. the infide of the radius, between der the utnaris externus and anco.nsaus,minimus, to which the llipinator longus, pronator teres, and the integuments, it is diftributed, as alfo to the fupinator brevis. giving branches to thefe and likewife to the perAfterward, this external interoffeous artery runs down foratus, perforans, and mufcles, fupinator brevis. From thenceon the outfide of die ligament, and is diftributed to the it runs, in a winding courfe, towards tiie extremity or the