Normal and pathological anatomy and physiology of the veins of the lower limbs

Veins of the lower limbs are divided into two regions: 1) the superficial region, composed of two saphenous veins, internal and external, and of their tributaries; 2) the deep region, composed of veins that are satellites (and homonyms) of the arteries (anterior and posterior tibial; peroneal; popliteal; superficial, deep and common femoral; external, epigastric and common iliac). The two networks are linked by perforating (or communicating) veins and by the arches of the two saphenous veins. Valvules are found in the venous network below the inguinal ligament; their number decreases with increasing proximity to the inferior vena cava. The function of the valves is the main factor in the physiology of venous circulation, in association with the force essentially provided by the "muscle pump" of the calf. The various forms of venous insufficiency are due to obstruction or incontinence of the veins.