REGION OF (UPPER) ARM 43 



In its proximal third the artery lies to the medial side of 

 the humerus and can be compressed laterally against the bone. 

 In ligature of this part the artery is found immediately under 

 the deep fascia, but it is overlapped laterally by the coraco- 

 brachialis, from which it is partially separated by the median 

 nerve. Both the medial cutaneous nerve of the forearm (internal 

 cutaneous) and the ulnar nerve (p. 38) lie to its medial side 

 and separate it from the basilic vein. Behind the artery lie 

 the long head of the triceps and the radial (musculo-spiral) nerve. 



The middle third of the brachial artery can be compressed 

 backwards and laterally against the bone. In ligation of 

 this part the artery is found to be overlapped by the medial 

 border of the biceps, and to be covered by the median 

 nerve, which crosses it very obliquely about the middle of the 

 arm. The ulnar nerve lies to its medial side, but is diverging 

 from the artery to reach the medial intermuscular septum. 

 Posteriorly, it lies on the insertion of the coraco-brachialis and 

 on the brachialis. The medial cutaneous nerve of the forearm 

 (internal cutaneous) and the basilic vein are both separated 

 from the vessel by the deep fascia, which they pierce at the 

 middle of the arm. 



The distal third of the artery lies in front of the distal 

 part of the humerus and can be compressed backwards against 

 it. In ligature of this part, the artery is found to be overlapped 

 by the medial border of the biceps, but near its termination it 

 lies to the medial side of the tendon of that muscle and is crossed 

 anteriorly by the lacertus fibrosus (bicipital fascia) (p. 45). 

 The median nerve lies to its medial side. 



Branches. (i) The (Superior) Pro/undo, arises near the commencement 

 of the brachial artery and runs with the radial (musculo-spiral) nerve. 



(2) The Superior Ulnar Collateral (Inferior Profunda) usually arises near 

 the middle of the arm (p. 44). 



(3) The Inferior Ulnar Collateral (Anastomolica Magnd) (p. 44). 



(4) The Nutrient artery usually arises from a muscular branch to the 

 brachialis ; it may be injured in fractures of the humerus, and, in these cases, 

 it is said that delayed union results. 



Collateral Anastomosis (a) Ligature Proximal to the Origin of the 

 Profunda Artery. The circulation is re-established through an anastomosis 

 which occurs between a descending branch from the posterior circumflex 

 (p. 1 8) and an ascending branch from the profunda. 



(V) Ligature between the Origins of the Profunda and the Superior Ulnar 

 Collateral (Inferior Profunda). The profunda artery divides into anterior 

 and posterior branches at the distal end of the radial (musculo-spiral) groove. 

 The anterior branch accompanies the radial (musculo-spiral) nerve into the 

 groove between the brachio-radialis and the brachialis to anastomose with 

 the radial recurrent, which enters the same groove at its distal end. The 



