334 ^ MANUAL OF ANATQMY 



The radial vein commences in the outer part of the plexus 

 on the back of the hand, and it ascends at first on the back of 

 the outer side of the forearm, but gradually inclines to its outer 

 aspect. . A little above the external epicondyle it joins the median 

 cephalic vein. 



The anterior ulnar vein commences on the inner aspect of the 

 front of the wrist, and it ascends in front of the inner side of the fore- 

 arm, to end either in the median basilic or by joining the posterior 

 ulnar vein. 



The posterior ulnar vein, of large size, commences in the inner 

 part of the plexus on the back of the hand, and it ascends along the 

 back of the inner side of the forearm to join the median basilic, 

 either separately or having previously taken up the anterior ulnar 

 vein. 



The principal superficial veins of the brachial region are the 

 cephalic and the basilic. 



The cephalic vein is formed by the union of the median cephalic 

 and the radial a little above the external epicondyle. It then 

 ascends, lying at first in the groove along the outer border of the 

 biceps, and then between the pectoralis major and deltoid. There- 

 after it crosses the first part of the axillary artery, and, piercing the 

 costo-coracoid membrane and axillary sheath, opens into the 

 axillary vein above the pectoralis minor. 



The basilic vein is formed by the union of the median basilic, 

 anterior ulnar, and posterior ulnar, just above the internal epicon- 

 dyle. It then ascends in the groove along the inner border of the 

 biceps, lying inside the line of the brachial artery. In the lower 

 half of the arm it is superficial to the deep fascia, but about the 

 centre it pierces it, and becomes the axillary vein at the lower border, 

 of the tendon of the teres major. In contact with the basilic vein, 

 just above the internal epicondyle, there are one or two lymphatic; 

 glands. 



FRONT AND INNER ASPECT OF BRACHIAL REGION. 



Deep Fascia. — The deep fascia or aponeurosis forms a continuous 

 investment to the arm, its fibres being principally disposed trans^ 

 versely, but others run more or less longitudinally. It is continuoi 

 above with the axillary fascia and the fascial investments of th^ 

 pectoralis major and deltoid, the tendons of which give expansior 

 to it. It is thin over the biceps, and somewhat thicker over thd 

 triceps, but it becomes specially strong in the region of the elbow| 

 where it is attached to the epicondyles of the humerus and olecranoi 

 process of the ulna. In front of the elbow it receives a considerably 

 accession of fibres from the bicipital or semilunar fascia. At abouj 

 the centre of the arm, on its inner aspect, it presents an opening fc 

 the passage of the basilic vein. The deep fascia is connected wit 

 the lower part of the humerus on either side by two deep processes 

 called intermuscular septa. The external septum is attached to thi 



