The veins of the lower limb, like those of the upper limb, are arranged in a superficial and deep set. The deep veins accompany their respective arteries, and are called by their names. The superficial veins are the:

Internal, or Long Saphenous.

External, or Short Saphenous.

The internal saphenous commences at the inner side of the venous arch, on the dorsum of the foot. It passes in front of the inner malleolus, and extends up the leg and inner side of the knee to the thigh, when it inclines forward, but goes up still on the inner aspect of the thigh, and joins the femoral vein by passing through an opening in the deep fascia, called the saphenous opening, about two inches below Poupart's ligament.

The external saphenous commences at the outer side of the dorsal arch, and passes behind the outer malleolus ; it ascends the back of the leg to the lower part of the popliteal space, when it pierces the deep fascia and joins the popliteal vein.

Fig. 58.—Long Saphenous Vein.

Both deep and superficial veins pour their contents into the external iliac veins ; the internal and external iliacs unite to form the common iliac veins ; the two common iliacs unite to form the inferior vena cava, which pierces the diaphragm, and carries the blood from all parts of the body below the heart to the lower part of the right auricle.

The valves in the veins of the lower limb are more numerous than in those of the upper limb.

The arteries send off branches all along their course. The veins' receive tributaries.