THE BRACHIAL OR AXILLARY ARTERIES. 



651 



magnum and niediuiii, and superficial pectoral muscles. Those which arrive in 

 the latter muscle traverse it only to become subcutaneous alternately ; one of 

 them accompanies the principal superficial vein of the forearm, and sends 

 ramuscules into the bend of the elbow. 



Regular iu their distribution, these ^'S- 376. 



different arteries present numerous 

 varieties of origin, among which it is 

 difficult to distinguish the most con- 

 stant disposition. The last-mentioned 

 vessel and the nutrient artery of the 

 humerus, often emanate directly from 

 the humeral trunk. 



4. Frituipal artery of flip hkq)s, or 

 coraco-radiaUs arterij (Fig. 37G, 6). — 

 This arises a little below or above the 

 preceding ; opposite to, or iu front of 

 it, it usually divides into two branches 

 — one ascending, the other descending, 

 which enter the substance of the 

 muscle. 



1. Anteeior Radial (or Spiral) 

 Artery (Figs. 376, 377). 



The anterior radial artery, the 

 smallest of the two terminal branches 

 of the humeral, separates at an acute 

 angle from the posterior artery, above 

 the articular condyle of the humerus. 

 It descends on the anterior face of the 

 ulnar articulation, passing beneath the 

 inferior extremity of the flexor muscles 

 of the forearm and the superior ex- 

 tremity of the extensor metacarpi, 

 where it meets the radial nerve ; in 

 company with this nerve, it extends 

 on the anterior face of the radius, 

 below the extensor metacarpi magnum, 

 to the knee, where it becomes very 

 thin and breaks up into several 

 ramuscules, which are continued on 



TERMINATIONS OF THE AXILLARY ARTERY 

 IN THE HORSE. 



A, Axillary portion of the brachial trunk. 1, 

 Supra-scapular artery; 2, infra-scapular artery; 



3, branch to the latissimus dorsi from the latter ; 



4, piehunieral or anterior circumflex artery; 



5, hiimeralis jirofunda ; 6, principal artery of 



the biceps; 7, internal collateral or cubital artery; 7', the point where it becomes the ulnar; 

 8, nutrient artery of the humerus, c, Posterior radial artery at its origin. 9, Muscular branch 

 of the posterior radial artery; 10. lu, collateral of the cannon, one of the terminal branches of 

 the posterior radial; 11, vessel common to the interosseous metacarpals, another branch of the 

 posterior radial artery. 



