546 VEINS. 



palmar surface of the hand and middle line of the forearm, communicating with 

 the anterior ulnar and radial veins. At the bend of the elbow, it receives a 

 branch of communication from the deep veins, accompanying the brachial 

 artery, and divides into two branches, the median cephalic and median basilic, 

 which diverge from each other as they ascend. 



The Median Cephalic, usually the smaller of the two, passes outwards in the 

 groove between the Supinator Longus and Biceps muscles, and joins with the 

 cephalic vein. The branches of the external cutaneous nerve pass behind this 

 vessel. 



The Median Basilic vein passes obliquely inwards, in the groove between the 

 Biceps and Pronator Radii Teres, and joins with the basilic. This vein passes 

 in front of the brachial artery, from which it is separated by a fibrous expan- 

 sion, given off' from the tendon of the Biceps to the fascia covering the flexor 

 muscles of the forearm. Filaments of the internal cutaneous nerve pass in front 

 as well as behind this vessel. 1 



The Deep Veins of the Upper Extremity follow the course of the arteries, 

 forming their venae comites. They are generally two in number, one lying on 

 each side of the corresponding artery, and they are connected at intervals by 

 short transverse branches. 



There are two digital veins, accompanying each artery along the sines of the 

 fingers; these, uniting at their base, pass along the interosseous spaces in the 

 palm, and terminate in the two superficial palmar veins. Branches from' these 

 vessels on the radial side of the hand accompany the superficialis volas, and on 

 the ulnar side terminate in the deep ulnar veins. The deep ulnar veins, as they 

 pass in front of the wrist, communicate with the interosseous and superficial 

 veins, and unite, at the elbow, with the deep radial veins, to form the venas 

 comites of the brachial artery. 



The Interosseous Veins accompany the anterior and posterior interosseous 

 arteries. The anterior interosseous veins commence in front of the wrist, 

 where they communicate with the deep radial and ulnar veins; at the upper 

 part of the forearnrthey receive the posterior interosseous veins, and terminate 

 in the venae comines of the ulnar artery. 



The Deep Palmar Veins accompany the deep palmar arch, being formed by 

 branches which accompany the ramifications of that vessel. They communi- 

 cate with the superficial palmar veins at the inner side of the hand; and on the 

 outer side terminate in the venae comites of the radial artery. At the wrist, 

 they receive a dorsal and a palmar branch from the thumb, and unite with the 

 deep radial veins. Accompanying the radial artery, these vessels terminate in 

 the venae comites of the brachial artery. 



TheBrachial Veins are placed one on each side of the brachial artery, receiv- 

 ing branches corresponding with those given off from that vessel ; at the lower 

 margin of the axilla they unite with the basilic to form the axillary vein. 



The deep veins have numerous anastomoses, not only with each other, but 

 also with the superficial veins. 



The Axillary Vein is of large size and formed by the continuation upwards 

 of the basilic vein. It commences at the lower part of the axillary space, in- 

 creases in size as it ascends, by receiving branches corresponding with those of 

 the axillary artery, and terminates immediately beneath the clavicle at the outer 

 margin of the first rib, where it becomes the subclavian vein. This vessel is 

 covered in front by the Pectoral muscles and costo-coracoid membrane, and lies 

 on the thoracic side of the axillary artery. Opposite the Subscapularis, it is 

 joined by a large vein, formed by the, junction of the venae comites of the bra- 



1 Cruveilhier says : " Numerous varieties are observed in the disposition of the veins of the 

 elbow; sometimes the common median vein is wanting; but in those cases, its two branches of 

 bifurcation are furnished by the radial vein, and the cephalic is almost always in a rudimentary 

 condition. In other cases, only two veins are found at the bend of the elbow, the radial and 

 ulnar, which are continuous, without any demarcation, with the cephalic and basilic." 



