890  HUMAN ANATOMY. 



The superficial veins of the palm of the hand are situated superficially to the 

 palmar aponeurosis. They are for the most part small, and form a net- work which 

 is open o\er the central part of the palm, but much closer over the thenar and 

 hypothenar eminences. These lateral portions communicate with the dorsal net-work 

 as well as the net-work of the anterior surface of the forearm, into which the central 

 portion opens. 



The Basilic Vein. 



The basilic vein (v. basilica) (Fig. 762) takes its origin from the ulnar side of 

 the dorsal net-work of the hand, and is sometimes described as the direct continuation 

 of the dorsal metacarpal vein of the fourth interspace. It passes obliquely upward and 

 inward, winding around the border of the hand towards the anterior surface of the fore- 

 arm, up which it ascends. Beyond the bend of the elbow it continues its wa:y upward 

 along the inner border of the biceps muscle as far as the upper third of the brachium, 

 at which level it pierces the fascia of the arm, and after a usually short subfascial 

 course terminates by opening into the internal brachial vein. 



The basilic is the largest of all the superficial veins of the arm, and is provided 

 with from ten to fifteen pairs of valves. It receives tributaries from the superficial 

 plexus of the thenar eminence and from the anterior and posterior surfaces of the 

 forearm. Near the elbow it receives from the cephalic vein the median vein, the 

 connecting stem being termed the median basilic vein, and it also communicates with 

 the cephalic higher up by branches which pass across the biceps muscle, and with the 

 brachial veins by small branches which pierce the brachial fascia. 



Variations. — The basilic is little subject to variation except in regard to its termination, 

 which is frequently in the axillary and sometimes in the subclavian ; in both these cases the sub- 

 fascial portion of its course is considerably longer than usual. Occasionally it is accompanied 

 throughout its course by an accessory basilic. 



The portion of the vein extending from its origin to the bend of the elbow is frequently 

 spoken of as the superficial ulnar vein, the term basilic being limited to the brachial portion of 

 the vein as described above. 



The Cephalic Vein. 



The cephalic vein (v. cephalica) (Fig. 762) takes its origin from the radial portion 

 of the dorsal net-work of the hand, and especially from the dorsal metacarpal vein 

 of the first interspace. It passes upward, inclining forward over the surface of the 

 brachio-radialis muscle, and so reaches the anterior surface of the forearm. Arrived 

 at the bend of the elbow, it ascends along the groove which marks the outer border of 

 the biceps muscle and then in the groove between the deltoid and the pectoralis major, 

 and at the upper border of the latter muscle it passes between it and the clavicle, per- 

 forates the costo-coracoid membrane, and, crossing in front of the a.xillary artery, 

 empties into the axillary vein. 



It is provided with from twelve to fifteen pairs of valves, of which from four to 

 seven occur in its antibrachial portion, seven in its brachial portion, and one at its 

 union with the axillary. 



Tributaries. — The cephalic vein receives numerous branches from the super- 

 ficial net-work of the posterior surface of the forearm and, indeed, plays a much 

 more important part in the drainage of this region than does the antibrachial portion 

 of the basilic. Quite frequently it is accompanied in its course up the forearm by an 

 accessory cephalic vein (v cephalica accessoria), which arises in the posterior super- 

 ficial net-work and opens into the main cephalic vein at the bend of the elbow. It 

 also receives bx-anches from the superficial net-work of the anterior surface of the 

 forearm and, a short distance below the bend of the elbow, gives off a strong branch, 

 the median vein (v. mediana cubiti), which passes obliquely upward and inward to 

 open into the basilic, giving off in its course a communicating branch to one or other 

 of the deep veins of the forearm. 



In its brachial portion it is connected with the basilic by branches which pass 

 across the biceps muscle, and just before opening into the axillary it receives the 

 acromial thoracic vein (v. thoracoacromialis), which corresponds to the artery of 

 the same name. 



