SUPERFICIAL VELXS OF UPPER EXTREMITY 041 



blood from the fingers are superficial and dorsally placed, the arteries are deep and 

 situated towards the palmar surface. Minute venie comites, however, lie on each 

 Bide of the digital arteries. 



The anterior median plexus is situated on the fore part of the wrist. It is 

 very irregular in its arraugeinent. and receives a few small l)ranches from the palm 

 and from the nuter ami fiont i»art of the thumb. 



The superficial radial vein begins at the radial end of the dorsal venous 

 ])lexus or arch, and, after receiving veins from the thumb and communicating with 

 the deep veins accompanying the radial artery, courses up the radial side of the 

 forearm along with the musculo-cutaneous nerve. It receives numerous branches 

 from the front and outer surface of the forearm, and a little above the bend of the 

 ell>ow, in the slight sulcus at the outer side of the bicipital prominence, unites with 

 tlie median ce})halie vein to form the cephalic vein (figs. 395, 396). It contains 

 from four to six valves. 



The anterior superficial ulnar vein begins on the inner and front surface of 

 tlie wrist, runs u]) the inner side of the foreann, and joins the posterior ulnar vein 

 just below the bend of the elbow; or it may unite directly with the median basilic 

 to form the basilic vein. In the latter case the posterior superficial ulnar vein joins 

 the basilic (fig. 395). The anterior ulnar vein is accompanied by the anterior 

 branch of the internal cutaneous ner^-e. It contains about four valves. 



The posterior superficial ulnar vein, larger than the anterior, begins at the 

 ' ulnar side of the dorsal plexus. It receives the vena salvatella, or vein of the 

 little finger, and communicates with the deep ulnar veins by means of an inter- 

 muscular branch which passes beneath the abductor minimi digiti. As it courses 

 upwards on the posterior aspect of the forearm it receives numerous cutaneous 

 l)ranches, and near the bend of the elbow joins the anterior superficial ulnar vein. 

 Just below the internal condyle the united trunk turns forwards to unite with the 

 median basilic to form the basilic vein. When the basilic is formed by the union 

 of the anterior ulnar and median basilic (fig. 395), the posterior ulnar vein may 

 end in the Viasilic vein direct. It contains about four valves. 



The superficial median vein begins in the anterior plexus in front of the 

 wrist, and losses up tlie centre of the front of the forearm, receiving numerous 

 cutaneous branches, and communicating on each side with the superfii'ial ulnar and 

 radial veins. At the bend of the elbow it receives the deep median vein, which 

 is formed V»y tlie union of the outer vena comes of the ulnar artery with the mus- 

 cular and radial recurrent veins. The short trunk pierces the deep fascia to join 

 the median vein, which immediately afterwards bifurcates into the median basilic 

 and median cejthalic. 



The median cephalic vein, the smaller branch of the median, runs upwards 

 and outwards in the sulcus between the biceps and supinatus longus, and, joining 

 the superficial radial vein immediately above the bend of the elbow, forms the 

 ce]ihalie vein. The musculo-cutaneous nerve passes beneath it, a few fibres of the 

 nerve lying superficial to it. 



The median basilic vein, tlie larger of the two divisions of the median vein, 

 runs upwards and inwards across the semilunar fascia of the Inceps, by which it is 

 separated from the brachial artery, to the internal bicipital sulcus, where it joins 

 one of the superficial ulnar veins or their united trunk to form the Ijasilic. Fibres 

 of the internal cutaneous nerve pass both in front and behind it. This vein is 

 especially prominent at the bend of the elbow; and, on account of its larger size 

 and superficial jiosition, was usually chosen in venesection when this operation was 

 in vogue. The lancet, if care was not taken, was liaVdeto i)ass through the bicipital 

 fascia and injure the artery, when varicose aneurysm f)r aneurysmal varix was 

 a common re-^ult. 



The cephalic vein, formed by the union of the median cephalic with the super- 

 ficial radial vein, courses upwards first in the external bicijiital sulcus, and then 

 in the interval between the pect oralis major and the deltoid, jierforates the costo- 

 coracoid membrane, and, crossing the first part of the axillary artery, opens into 

 the axillarv vein. It contains a pair of valves where it joins the axillary vein. 



The basilic vein — formed by the union of the median basilic and one of the 

 superficial ulnar veins or their united trunk — jiasses u\> the inner side of the arm 

 41 



