74 THE UPPER EXTREMITY 



in the proximal part, after the vein has pierced the fascia, it 

 comes into closer relationship with the artery. The two 

 venae comites are closely applied to the sides of the artery, 

 and the numerous connecting branches which pass between 

 them, both in front of and behind the artery, make the 

 relationship still more intimate. 



Behind the brachial artery there are four muscles. From 

 above downwards they are (i) the long head of the triceps 

 which is separated from the artery by the radial nerve and the 



N. musculo- 

 cutaneus ' 



hept. inter- 

 5j-- muse. lat. 

 | Hrs. of A. prof. 

 [-- brachii 



I N. radialis 



~ (musculo-spiral) 



Dorsal cutaneous nerve of arm (O.T. 

 , internal cutan. of musculo-spiral) . 



FIG. 31. Transverse section through Middle of Upper Ann. 



profunda artery. (2) The medial head of the triceps. (3) The 

 insertion of the coraco-brachialis. (4) In the remainder of 

 its course the brachialis forms the posterior relation. 



With the exception of the musculo-cutaneous nerve all 

 the terminal branches of the brachial plexus lie in relation 

 to the brachial artery. The median nerve lies laterally 

 and somewhat anteriorly in the proximal half of the arm ; it 

 crosses anterior to the artery at the level of the insertion of 

 the coraco-brachialis, and in the distal half of the arm and 

 the cubital fossa it is to the medial side of the artery. The 

 ulnar nerve and the medial cutaneous nerve of the forearm 

 lie close to the medial side of the artery as far as the 



