

THE REGION OF THE ELBOW. 147 



the internal cutaneous, lesser internal cutaneous, median 

 and musculo-cutaneous. The superficial veins are de- 

 rived principally from the radial, ulnar, and median 

 veins, and at the outer border of the biceps tendon the 

 median joins the basilic, by means of a large oblique 

 branch, the median basilic; and also the cephalic, by a 

 similar branch ; the median cephalic, directed along the 

 lower border of the biceps. At the point of bifurcation, 

 the aponeurosis of the forearm is perforated by a com- 

 munication between these veins and those accompanying 

 the brachial artery, also between the superficial and deep 

 lymphatics. The aponeurosis of the bend of the elbow 

 is a continuation of the brachial, and is strengthened 

 internally by an offset from the tendon of the biceps 

 (the bicipital fascia). It is this process which separates 

 the median basilic vein from the brachial artery. It 

 receives, moreover, posteriorly, a slip from the tendon 

 of the triceps, is attached to both condyles, and has a 

 further slip from the brachialis anticus tendon. 



On reflecting the aponeurosis, the mass of muscles 

 which form the boundaries of the space are brought into 

 view. Externally, from above downwards, in order, are 

 the supinator longus, extensor carpi radialis longior and 

 brevior, covering the lower and external part of the 

 humerus, and the external lateral ligament. Internally, 

 the common tendon of origin of the flexors and prona- 

 tors of the wrist and forearm above ; and passing between 

 these muscular masses are, externally, the tendon of the 

 biceps ; internally, the tendon of the brachialis anticus, 

 covering in the anterior part of the articulation, part of 

 the head of the radius, and the coronoid process. These 

 muscles form two wedge-like troughs, in the outer of 

 which lie the musculo-spiral nerve, superior profunda 



