OF THE TIPPER EXTREMITY. 467 



inner side of the forearm to the bend of the elbow, where it joins with the posterior 

 ulnar vein to form the basilic. It communicates with branches of the median 

 vein in front, and with the posterior ulnar behind. 



The Posterior Ulnar Vein commences on the posterior surface of the ulnar 

 side of the hand, and from the vein of the little finger (vena salvatella), situated 

 over the fourth metacarpal space. It ascends on the posterior surface of the ulnar 

 side of the forearm, and just below the elbow unites with the anterior ulnar vein 

 to form the basilic. 



The Basilic is a vein of considerable size, formed by the coalescence of the 

 anterior and posterior ulnar veins ; ascending along the inner side of the elbow, it 

 receives the median basilic vein, and, passing upwards along the inner side of the 

 arm, pierces the deep fascia, and ascends in the course of the brachial artery, ter- 

 minating either in one of the vena3 comites of that vessel, or in the axillary vein. 



The Radial Vein commences from the dorsal surface of the thumb, index finger, 

 and radial side of the hand, by branches which communicate with the vena salva- 

 tella. They form by their union a large vessel, which ascends along the radial 

 side of the forearm, receiving numerous branches from both its surfaces. At the 

 bend of the elbow it receives the median cephalic, when it becomes the cephalic 

 vein. 



The Cephalic Vein ascends along the outer border of the Biceps muscle, to the 

 upper third of the arm ; it then passes in the interval between the Pectoralis major 

 and Deltoid muscles, accompanied by the descending branch of the thoracica acro- 

 mialis artery, and terminates in the axillary vein just below the clavicle. This 

 vein is occasionally connected with the external jugular or subclavian, by a branch 

 which passes from it upwards in front of the clavicle. 



The Median Vein collects the blood from the superficial structures in the 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, the smaller of the two, passes outwards in the groove 

 between the Supinator longus and Biceps muscles, and joins with the cephalic 

 vein. T'ue 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 expansion, 

 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 of as well 

 as behind this vessel. 



2. 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 sides 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 vola3, 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 venje comites of the 

 brachial artery. 



The InterosseoiLS 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 

 forearm they receive the posterior interosseous veins, and terminate iu the venae 

 comites of the ulnar artery. 



