344 FEMORAL VEIN VEINS OF THE TRUNK. 



VEINS OF THE LOWER EXTREMITY. 



The veins of the lower extremity are the deep and superficial. The 

 deep veins accompany the branches of the arteries in pairs, and form the 

 venaB comites of the anterior and posterior tibial and peroneal arteries. 

 These veins unite in the popliteal region to form a single vein of large 

 size, the popliteal, which successively becomes in its course the femoral 

 and the external iliac vein. 



POPLITEAL VEIN. 



The popliteal vein ascends through the popliteal region, lying, in the 

 first instance, directly upon the artery, and then getting somewhat to its 

 outer side. It receives several muscular and articular branches, and the 

 external saphenous vein. The valves in this vein are four or five in 

 number. 



FEMORAL VEIN. 



The femoral vein, passing through the opening in the adductor magnus 

 muscle, ascends the thigh in the sheath of the femoral artery, and entering 

 the pelvis beneath Poupart's ligament, becomes the external iliac vein. 

 In the lower part of its course it is situated upon the outer side of the 

 artery ; it then becomes placed behind that vessel, and, at Poupart's liga- 

 ment, lies to its inner side. It receives the muscular veins, and the pro- 

 runda, and, through the saphenous opening, the internal saphenous vein. 

 The valves in this vein are four or five in number. 



The Profunda vein is formed by the convergence of the numerous small 

 veins which accompany the branches of the artery ; it is a vein of large 

 size, lying in front of the profunda artery, and it terminates in the femoral 

 at about an inch and a half below Poupart's ligament. 



The Superficial veins are the external or short, and the internal or long 

 saphenous. 



The External saphenous vein collects the blood from the outer side of 

 the foot and leg. It passes behind the outer ankle, ascends along the 

 posterior aspect of the leg, lying in the groove between the two bellies of 

 the gastrocnemius muscle, and pierces the deep fascia in the popliteal 

 region to join the popliteal vein. It receives several cutaneous branches 

 in the popliteal region before passing through the deep fascia, and is ac- 

 companied in its course by the external saphenous nerve. 



The Internal saphenous vein commences upon the dorsum and inner 

 side of the foot. It ascends in front of the inner ankle, and along the 

 inner side of the leg ; it then passes behind the inner condyle of the femur 

 and along the inner side of the thigh to the saphenous opening, where it 

 pierces the sheath of the femoral vessels, and terminates in the femoral 

 vein, at about one inch and a half below Poupart's ligament. 



It receives in its course the cutaneous veins of the leg and thigh, and 

 communicates freely with the deep veins. At the saphenous opening it 

 is joined by the superficial epigastric and circumflexa ilii veins, and by 

 the external pudic. The situation of this vein in the thigh is not unfre- 

 quently occupied by two or even three trunks of nearly equal size. 



VEINS OF THE TRUNK. 



The veins of the trunk maybe divided into, 1. The superior vena cava, 

 with its formative branches. 2. The inferior vena cava, with its formative 



