THE AR.TERIES. 297 



the brachial proximad of the supracondyloid foramen, either 

 separately or in common with the muscular branches, and 

 passes into the nutrient foramen at the junction of the middle 

 and distal thirds of the shaft of the humerus, supplying the 

 bone. 



d. A. collateralis ulnaris (superior) (or A. anastomotica 

 magna) {s). — This leaves the brachial artery just proximad of 

 the supracondyloid foramen and passes to the convexity of the 

 elbow, supplying the structures about the olecranon. 



e. A. collateralis radialis superior (Fig. 130). — This rises 

 from the axillary artery just proximad of the supracondyloid 

 foramen (Fig. 122, x), in company with the vena medianacubiti 

 (j'), passes across the surface of the biceps (4), beneath the 

 pectoantibrachialis, into the concavity of the elbow. Here it 

 gives branches to the pectoantibrachialis, clavobrachialis, and 

 extensor muscles of the forearm. It then passes onto the ven- 

 troradial border of the forearm (Fig. 130) and runs along this 

 border, in company with the vena cephalica (Fig. 130, r) and 

 the superficial radial nerve {g), to the wrist, sending off 

 branches to the integument. At the wrist it turns onto the 

 dorsum of the hand, passing in a gentle curve to the ulnar side 

 and distad, and giving off a branch for the space between each 

 pair of metacarpal bones. These branches (Fig. 130, c) 

 (Aa. digitales dorsales) pass distad and anastomose with 

 branches coming from the palm. 



/. A. radialis (Fig. 123).- — Distad of the convexity of the 

 elbow the brachial artery takes the name radial artery. It 

 passes from the supracondyloid foramen on the medial side of 

 the biceps tendon (1) and beneath the pronator teres muscle 

 (5), giving off small branches, as far as the middle of the fore- 

 arm, where it gives off the ulnar artery (/'). It then passes 

 from beneath the pronator teres (5) and lies on the surface of 

 the fifth part of the flexor profundus (8 ), covered only by the 

 fascia and integument. Near the wrist it sends off a branch 

 (;;/) toward the ulnar side of the arm, which passes into the 

 palm on the surface of the tendon of the flexor profundus, 

 giving twigs to the digits and to the pad in the palm. A 

 branch from this may join the ulnar, and the common trunk 



