BRANCHES OF THE ULNAE ARTERY. 



443 



between that process and the olecranon it lies beneath the flexor carpi ulnaris, and, 

 passing between the heads of this muscle along the ulnar nerve, supplies branches to 

 the muscles, to the elbow-joint, and to the nerve itself. This branch communicates 

 with the inferior profunda, the anastomotic, and over the olecranon also with the 

 posterior interosseous recurrent. 



3. The interosseous or common interosseous artery (iv), the largest 

 branch, is a short trunk which arises from the ulnar artery about an inch from its 

 commencement, and inclines backwards to reach the upper border of the 

 interosseous membrane, where it divides into the anterior and posterior^ interosseous 

 arteries. 



The anterior interosseous artery descends upon the front of the interosseous 

 membrane, accompanied by the interosseous branch of them edian nerve and venae 



Fig. 362. THE ANASTOMOSES OF THE EL- 

 BOW : A, FROM BEFOKE ; B, FROM BE- 

 HIND. (R. Quain. ) g 



A. a, brachialis anticus muscle ; b, ex- 

 ternal condyle, covered by the anastomoses 

 of the superior profunda and radial recurrent 

 arteries ; c, ulnar nerve ; d, median nerve ; 

 e, musculo-spiral nerve ; e', its posterior in- 

 terosseous branch ; its radial branch is cut 

 short ; 1, brachial artery ; 2, radial ; 3, 

 ulnar ; 4, inferior profunda ; 5, anasto- 

 motic ; 6, anterior ulnar recurrent, anasto- 

 mosing with the anterior branch of the 

 anastomotio ; 7, posterior ulnar recurrent, 

 passing up behind the inner condyle to anas- 

 tomose with the inferior profunda and pos- 

 terior branch of the anastomotic ; 8, anterior 

 terminal branch of superior profunda ; 9, on 

 the tendon of the biceps muscle, points to 

 the radial recurrent artery ; 10, 10, interos- 

 seous artery and its anterior branch. 



B. a, brachialis anticus muscle ; 6, ex- 

 ternal lateral ligament of the elbow-joint ; c, 

 ulnar nerve ; d, a small part of the musculo- 

 spiral nerve ; 1, superior profunda artery ; 

 2, branch which descends in the inner head 

 of the triceps muscle ; 3, its posterior ter- 

 minal branch ; 4, branches of the radial 

 recurrent ; 5, posterior interosseous recur- 

 rent, anastomosing with the preceding and * 

 with the posterior ulnar recurrent ; 6, 

 inferior profunda ; 7, 7, anastomotic ; 8, 



anastomosis of the inferior profunda and anastomotic with the superior profunda; 9, posterior 

 ulnar recurrent, anastomosing with the inferior profunda and anastomotic. 



comites, and overlapped by the contiguous borders of the flexor profundus digitorum 

 and flexor longus pollicis muscles. It continues its course directly downwards as 

 far as the upper border of the pronator quadratus muscle, then pierces the inter- 

 osseous membrane, and descends to the back of the carpus. It gives off the 

 following branches : 



(a) The median artery, a long slender branch, which accompanies the median 

 nerve, and sends offsets into its substance and to the flexor sublimis digitorum. 

 This artery is sometimes much enlarged and assists in supplying the hand, as will 

 be hereafter noticed. 



(b) Muscular branches to the flexor profundus, flexor longus pollicis, and 

 pronator quadratus muscles, and others which perforate the interosseous membrane 

 to supply the extensors of the thumb. 



(c) The medullary arteries of the radius and ulna, which enter the foramina in 

 those bones to be distributed in their interior. 



