Vein system

Deep venous system (1), superficial venous system (2), connecting veins (3)

The leg veins can be divided into superficial and deep veins or into the superficial and deep vein system. The superficial veins run in and just beneath the skin. They transport blood from the skin and subcutaneous tissues into the deep vein system, accounting for some 10% of the blood carried back to the heart from the legs. The deep vein system lies deeper inside the leg and is responsible for about 90% of the return blood flow. The superficial and deep systems are joined together at certain points by perforating veins.