264 THE VASCULAR SYSTEMS 



arteries. Its dorsalis scapulas branch passes through a triangle 

 formed by the two teres and the triceps, and divides into three 

 sets, viz., dorsal, to the infraspinous fossa; ventral, to the 

 subscapular fossa; and descending, to run between the teres 

 muscles. 



The circumflex arteries encircle the neck of the humerus. 

 The posterior, with the nerve and veins, passes through the 

 quadrangular space formed by the triceps, teres, and humerus, 

 and ends in the deltoid and shoulder-joint. The anterior, 

 beneath the biceps and coracobrachialis, to end under the del- 

 toid, sends a twig to the shoulder-joint along the bicipital groove. 



The Brachial Artery 



The brachial artery extends from the end of the axillary, 

 at the lower border of the teres major, to \ inch below the elbow 

 joint, dividing into the radial and ulnar arteries. 



Relations. In front, integument and fascia, bicipital fascia, 

 median basilic vein, and median nerve; behind, triceps, coraco- 

 brachialis, brachialis anticus, musculospiral nerve, and superior 

 profunda artery; externally, coracobrachialis, biceps, median 

 nerve above; internally, basilic vein, venae comites, internal 

 cutaneous, ulnar nerve, and median nerve below. 



The branches of the brachial artery are : 



(a) The superior profunda, along the musculospiral groove, 

 sends a branch of the shoulder-joint, anastomosing with the 

 circumflex; the posterior articular artery, to the back of the 

 elbow, joining the interosseous recurrent; branches to muscles; 

 and, finally, the continuation of the vessel joins the radial 

 recurrent in front of the outer condyle. 



(6) The nutrient artery, to the humerus, enters the foramen. 



(c) The inferior profunda, on the inner head of the triceps, 

 accompanies the ulnar nerve, and divides into a branch to the 

 front of the inner condyle and another to the back of it. The 

 former joins the anterior, and the latter the posterior ulnar 

 recurrent artery. 



(d) The muscular branches, to the coracobrachialis, biceps, 

 and brachialis anticus. 



(e) The anastomotica magna comes off about 2 inches above the 

 elbow and runs on the brachialis anticus inward to form an 



