THE VASCULAR SYSTEM 



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subscapular, which is ahnost as 

 large as the continuation of the 

 axillary, now called the brachial 

 from this point on. The sub- 

 scapular, about a centimeter 

 from its origin gives off the 

 thoracodorsalis to the teres 

 major, latissimus dorsi, and epi- 

 trochlearis muscles; and the 

 posterior circumflex which winds 

 around the neck of the humerus 

 to its distribution in the triceps 

 and deltoid muscles. The sub- 

 scapular may also give origin to 

 the anterior circumflex and deep 

 branchial arteries, although 

 these usually arise from the 

 brachial. 

 The brachial artery, in addition 

 to several muscular branches, 

 gives origin to the anterior cir- 

 cumflex, superior profunda, the 

 nutrient, and anastomotica 

 magna. The anterior circum- 

 flex supplies the biceps and head 

 of the humerus. The superior 

 profunda is distributed to the 

 muscles on the caudal aspect of 

 the humerus. The nutrient 

 artery enters the nutrient fora- 

 men of the humerus. The an- 

 astomotica magna or superior 

 ulnar collateral artery is the 

 small branch supplying the con- 

 vexity of the elbow. The 

 superior collateral radial artery 

 rises at about the same point 



Fig. 8o. — Arteries of the Forelimb; 

 Ventral Aspect. 

 a. Digital artery, aw, anastomotica 

 magna; ac, anterior circumflex; ai, an- 

 terior interosseous; ax, axillary; at, 

 anterior thoracic; b, digital artery; 

 be, innominate; br, brachial; c, dorsal 

 branch of the radial where it passes 

 between the second and third metacar- 

 pals to the palmar side; ex, circum- 

 flex; is, superior intercostal; Is, left 

 subclavian; //, long thoracic; m, branch 

 to extensor muscles; nt, nutrient; pi, 

 posterior interosseous; r, radial; rd, 

 radial recurrent; sf, supracondyloid 

 foramen of the humerus; spr, superior 

 profunda; sb, subscapularis; sp, supra- 

 scapularis; si, sternal; th, thyreoid 

 axis; id, ulnar; iir, ulnar recurrent; 

 vl, vertebral. 



