360 THE INFERIOR EXTREMITY 



mences at the medial border of the foot, where it is formed 

 by the union of the medial end of the dorsal venous arch of 

 the foot with the medial digital vein of the great toe. It 

 ascends anterior to the medial malleolus, passes obliquely 

 upwards and backwards across the medial surface of the distal 

 third of the tibia, and then vertically upwards, along the 

 medial border of the tibia, to the posterior part of the medial 

 side of the knee. Thence it passes obliquely upwards, 

 forwards, and laterally, through the superficial fascia of the 

 medial and anterior areas of the thigh, to the fossa ovalis, 

 where it pierces the cribriform fascia and the femoral sheath 

 and terminates in the femoral vein (Figs. 163, 107, 106). 



Its named tributaries are the dorsal venous arch, the 

 medial digital vein of the great toe, the lateral and medial 

 femoral circumflex veins (p. 230), the superficial pudendal, 

 epigastric, and circumflex iliac veins (p. 230), but it receives 

 in addition numerous other tributaries from the dorsum of 

 the foot, and from the front, medial side, and back of the 

 leg. Further, it forms numerous communications with the 

 deep veins of the limb by anastomosing channels which 

 pierce the deep fascia. A fairly large communicating 

 vein pierces the ligamentum laciniatum and curves below the 

 medial malleolus to join the great saphenous vein at the 

 anterior border of that process ; others pierce the deep fascia 

 along the medial borders of the tibia and in the distal third 

 of the thigh. 



The great saphenous vein is accompanied by numerous 

 superficial lymph vessels. They drain the regions from 

 which the tributaries of the vein issue, and they terminate 

 in the medial and lateral groups of subinguinal lymph glands, 

 which lie at the sides of the proximal part of the vein in the 

 region of the femoral triangle. It is also accompanied by 

 several cutaneous nerves from the fossa ovalis to the middle 

 of the thigh by branches of the medial cutaneous nerve of 

 the thigh, from the middle of the thigh to the knee by the 

 anterior terminal branch of the medial cutaneous nerve of the 

 thigh, and from the knee to the medial border of the foot 

 by the saphenous nerve. 



It contains a number of valves which help to divide the 

 long column of blood into a series of segments, and so 

 diminish the pressure on the walls of the more distal parts 

 of the vein. 



