DEEP VEINS OF THE UPPER EXTREMITY 671 



Beginning at the fingers, two minute proper volar digital veins [vense digitales 

 volares propriae], accompany each digital artery along the sides of the fingers, 

 and uniting at the cleft, form common volar digital veins [vv. digitales volares 

 communes], which join the vense comitantes of the arteries, forming the super- 

 ficial palmar arch. In like manner the veins accompanying the arteries forming 

 the deep arch receive tributaries, the volar metacarpal veins [vv. metacarpese 

 volares], corresponding to the branches of that arch. A superficial and a deep 

 volar venous arch [ arcus volaris venosi superficialis et profundus] are thus formed 

 accompanying the arterial arches. The vense comitantes from the ulnar side of 

 the superficial and deep arches unite at the spot where the ulnar artery divides 

 into the superficial and deep branch to form two ulnar venae comitantes [vv. 

 ulnares] ; whilst those on the radial side of the superficial and deep arch accompany 

 the superficial volar artery and the termination of the radial artery respectively, 

 and unite at the spot where the superficial volar is given off from the radial artery, 

 to form the radial venae comitantes [vv. radiales]. The ulnar and radial vense 

 comitantes thus formed course up the forearm with their respective arteries, 

 receiving numerous tributaries from the muscles amongst which they run, and 

 giving frequent communications to the superficial veins. They finally urute at 

 the bend of the elbow to form the brachial venae comitantes [vv. brachiales]. 

 The ulnar vense comitantes receive, before joining the radial, the companion 

 veins of the interosseous arteries. At the bend of the elbow the deep veins are 

 connected with the basilic or with the median antibrachial vein by a short, thick 

 trunk (fig. 528). 



The brachial venae comitantes accompany the brachial artery. At the lower 

 border of either the teres major or subscapularis muscle, the more medial vein 

 receives the more lateral and the basilic vein, to form a single axillary vein. 



The vense comitantes of the arteries of the arm anastomose with one another 

 by frequent cross branches. 



The axillary vein [v. axillaris], is formed by the junction of the medial brachial 

 vena comitans with the basilic vein at the lower border of either the teres major 

 or subscapularis muscle. It is a vessel of large size, conveying as it does nearly 

 the whole of the returned blood from the upper extremity. It accompanies the 

 axillary artery through the axillary fossa, lying to its medial side and, at the upper 

 part of the space, on a slightly posterior plane. At the lateral border of the first 

 rib it changes its name to the subclavian. It has one or two axillary lymphatic 

 nodes in close connection with it, and is liable, if care is not taken, to be wounded 

 in removing these glands. The vein contains a pair of valves, usually placed 

 near the lower border of the subscapularis muscle. 



Tributaries : — (1) The subscapular veins which accompany the subscapular 

 artery; (2) the circumflex veins accompanying the circumflex arteries; (3) the 

 lateral thoracic vein [v. thoracalis lateralis] a large vein which accompanies 

 the lateral thoracic artery and receives numerous thoraco-epigastric veins [vv. 

 thoracoepigastricae] from the epigastric and lower thoracic regions; (4) the costo- 

 axillary veins [vv. costoaxillares] the radicles of which arise in the pectoral region 

 from the mammary plexus [plexus venosus mamillae]; and (5) the cephalic vein. 



The subclavian vein [v. subclavii] (fig. 528), is the continuation of the axillary. 

 It begins at the lateral border of the first rib, and terminates by joining the 

 internal jugular to form the innominate vein opposite the lateral end of the 

 sterno-clavicular articulation. It lies anterior to the subclavian artery and on a 

 lower plane, and is separated from the artery in the second part of its course 

 by the scalenus anterior muscle. The subclavian vein, just before it is joined by 

 the external jugular, contains a pair of valves. 



Tributaries. — The subclavian vein receives the thoracoacromial vein near its 

 distal end, and the external jugular vein near the lateral border of the sterno- 

 mastoid muscle. The transverse cervical veins terminate in the subclavian near 

 the external jugular, or in the latter vein, or in a plexiform arrangement formed 

 between the transverse scapular, transverse cervical and external jugular veins. 

 The external jugular vein is described with the superficial veins of the head 

 and neck (p. 646). 



The thoracoacromial vein [v. thoracoacromialis], receiving tributaries cor- 

 responding to the branches of the artery of the same name, terminates near the 

 lateral border of the first rib. 



