214 



SURGICAL APPLIED ANATOMY. [Chap xm. 



of the biceps tendon, and, therefore, the latter vein 

 passes in front of the tendon, of the brachial artery 

 and its veins, and of the median nerve. From 

 these structures it is separated by the bicipital fascia. 

 The median basilic vein may 

 cross the brachial artery ab- 

 ruptly, and be comparatively 

 free of it, except at the point 

 of crossing, or it may run for 

 some distance quite in front 

 of the artery, or, crossing it 

 early, it may lie parallel with 

 the vessel, although at a diffe- 

 rent level, for the greater part 

 of its course. As regards size, 

 the median basilic is usually 

 the largest of these veins, the 

 median cephalic coming next, 

 and the median itself third, 

 while the ulnar and radial veins 

 are the smallest of the series. 

 These veins are liable to many 

 abnormalities, some of the most 

 conspicuous being in cases where 

 the main arteries of the part are 

 Fig. 23. The Left Elbow a i so abnormal. The deviation 



from in front. . . 



a, Basilic vein; 6, -cephalic is more usual in the veins on 



jSia&^SK^ffi the radial than in those on the 



Sedian e ^Sir^ein; ulnar side of the limb. Thus 



^^,Ubr m SSS it is common for the radial or 



the median cephalic veins, or 



both, to be either very defective or entirely absent. 

 In spite of the relation the median basilic vein 

 bears to the brachial artery, it is nevertheless 

 the vein usually selected in venesection. The 

 reasons for its selection are these : it is usually 

 the largest and most prominent of the veins, and 



