UPPER EXTREMITY AND THORAX, ANTERIOR. 283 



and the median receives the deep median vein from the in- 

 terior of the forearm and divides into the median cephalic 

 and median basilic. The deep median vein is formed by 

 the venae comites of the ulnar, radial recurrent, and mus- 

 cular arteries. 



The median cephalic joins the radial vein to form the 

 cephalic, which passes upward in the groove at the outer 

 border of the biceps muscle. 



The median basilic joins with the common ulnar to 

 form the basilic, which ascends in the inner brachial groove, 

 pierces the deep fascia in the middle and lower thirds of the 

 arm, and terminates as one of the tributaries forming the 

 axillary vein. 



The Superficial Nerves. Figs. 62, 63, 65. 



These are, on the inside of the arm, branches of the 

 intercostohumeral, lesser internal cutaneous, internal cuta- 

 neous ; on the outside, the cutaneous branches of the cir- 

 cumflex and the superior external cutaneous branch of the 

 musculospiral. 



In the forearm there are, on the inside, the anterior divi- 

 sion of the internal cutaneous, which reaches to the wrist ; 

 on the outer side, the external cutaneous branch of the 

 musculocutaneous, which is distributed as low as the ball 

 of the thumb. 



The Deep Fascia. Figs. 61, 65. 



The deep fascia of the arm and forearm encases the 

 muscles like a tight sleeve, forming their compartments and 

 fixing them in position. Above it is continuous with the 

 deep fascia covering the deltoid, pectoralis major, teres 

 major, latissimus dorsi, and axillary space. Through these 

 extensions it passes to the spine and acromion process of 

 the scapula and the clavicle. Below, the fascia is attached 



