_a._ =A. circumflexa humeri anterior= (_l_′).--The anterior circumflex artery usually leaves the brachial near its origin (but may arise from the subscapular (_l_) or one of its branches); it passes to the biceps (4) near the origin of the latter and sends a branch proximad to the head of the humerus. _b._ =A. profunda brachii= or superior profunda (_u_).--This arises from the first part of the brachial or it may come off from one of the branches of the axillary (e.g., the subscapularis). It passes along with the radial nerve onto the dorsal side of the humerus and supplies the triceps muscle. It also sends branches to the epitrochlearis (6) and latissimus dorsi (7). _c._ =Rami musculares.=--Muscular branches are given off near the supracondyloid foramen to the biceps (4), epitrochlearis (6), and brachialis muscles. A nutrient artery leaves 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) (_z_).--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 mediana cubiti (_y_), 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 ventroradial border of the forearm (Fig. 130) and runs along this border, in company with the vena cephalica (Fig. 130, _c_) 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, _e_) (=Aa. digitales dorsales=) pass distad and anastomose with branches coming from the palm.