THE UPPER LIMB 335 



external epicondyle, and external supracondylar ridge as high as a 

 point posterior to the lower part of the tendon of insertion ot the 

 deltoid, with which it is connected. It gives origin posteriorly to 

 fibres of the inner head of the triceps, below where it is pierced by the 

 musculo-spiral nerve, and above that point to fibres of the external 

 head. Anteriorly, from above downwards, it gives origin to a small 

 part of the brachialis anticus, brachio-radialis, and extensor carpi 

 radialis longior. It is pierced from behind forwards by the musculo- 

 spiral nerve and the anterior terminal branch of the superior profunda 

 artery, the posterior terminal branch descending behind it. The 

 internal septum is stronger than the external, and is attached to the 

 internal epicondyle, and internal supracondylar ridge as high as a 

 point behind the insertion of the coraco-brachialis. It gives origin 

 anteriorly to the brachialis anticus, and posteriorly to the inner head 

 of the triceps. It is pierced, at its upper part, from before back- 

 wards by the ulnar nerve and inferior profunda artery, and, a little 

 above the elbow, by the posterior branch of the anastomotica magna 

 artery. Connected with the internal septum there is a fibrous 

 band, known as the internal brachial ligament (Struthers), which 

 extends from the humerus below the tendon of insertion of the teres 

 major to the internal epicondyle. The two intermuscular septa 

 divide the lower half of the arm into two compartments — anterior 

 and posterior. The anterior compartment contains the biceps, 

 brachialis anticus, brachio-radialis, extensor carpi radialis longior, 

 basilic vein, brachial vessels, median nerve, ulnar nerve for a short 

 distance above, internal cutaneous nerve, nerve of Wrisberg, and 

 musculo-spiral nerve after it has pierced the external septum. The 

 posterior compartment contains the triceps and a smaH part of the 

 musculo-spiral nerve. 



Internal Epicondylar Lymphatic Glands. — ^These glands, usually 

 two in number, are situated about li inches above the internal 

 epicondyle of the humerus. They lie superficial to the deep fascia, 

 and in close proximity to the commencement of the basilic vein. 

 Their afferent vessels are derived from (i) the inner three fingers, 

 (2) the inner part of the palm, and (3) the ulnar side of the forearm. 

 Their efferent vessels ascend with the basilic vein, and, about the 

 centre of the arm, they pass with the basilic vein through an opening 

 in the deep fascia. Thereafter they join the deep hTnphatics along 

 the brachial artery, which terminate in the external axillary glands. 



Anticubital Lymphatic Glands. — ^These are very inconstant. 

 When present they are about two in nimiber, and lie opposite the 

 bend of the elbow, superficial to the deep fascia. They receive 

 their afferent vessels from the centre of the palm and the front of 

 the forearm. Their efferent vessels ascend superficially along the 

 inner border of the biceps brachii, and, piercing the deep fascia, 

 they terminate in the external axillary glands. 



Coraco-brachialis — Origin. — (i) The tip of the coracoid process of 

 the scapula ; and (2) the inner aspect of the tendon of the short head 

 of the biceps for 3 inches or more. 



