296 THE CIRCULATORY SYSTEM. 



glenoid border as far as the glenovertebral angle, supplying 

 the infraspinatus and latissimus dorsi by lateral branches. 



A. thoracicodorsalis (/). — This arises from the subscapular 

 a short distance from its origin and passes across the teres 

 major to the latissimus dorsi (7), giving branches to both these 

 muscles and to the epitrochlearis. 



A. circumflexa humeri posterior, — The posterior circum- 

 flex artery arises from the A. subscapularis close to the origin 

 of the latter. It passes between the subscapularis muscle and 

 the teres major, close to the border of the biceps, then between 

 the lateral and long heads of the triceps. It gives off a branch 

 to the inner surface of the spinodeltoid and acromiodeltoid, 

 then passes distad to supply the lateral and long heads of the 

 triceps. 



4. A. brachialis (^').— The brachial artery is the con- 

 tinuation of the axillary (^) into the arm beyond the origin of 

 the subscapular (/). It passes along that side of the biceps 

 which lies next to the humerus. It passes thus, accompanied 

 by the brachial vein (/') and median and ulnar nerves, through 

 the bicipital arch and afterwards between the biceps (4) and 

 the intermediate division of the medial head of the triceps to 

 the supracondyloid foramen of the humerus, through which 

 it passes with the median nerve to reach the concavity of the 

 elbow. It gives off the following branches: 



a. A. circumflexa humeri anterior (/'). — The anterior cir- 

 cumflex artery usually leaves the brachial near its origin (but 

 may arise from the subscapular (/) 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 (//). — 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 (fi) and latissimus dorsi (7). 



c. Rami musculares. — Muscular branches arc given off 

 near the supracondyloid foramen to the biceps (4), epitro- 

 chlearis (6), and brachialis muscles. A nutrient artery leaves 



