The veins of the pelvis and the lower limb drain the deoxygenated blood and return it to the systemic circulation and the right atrium of the heart.
There are three major veins providing the venous drainage from the pelvic walls and viscera: the external iliac vein, the internal iliac vein, and the common iliac vein. These veins of the pelvis correspond to the major pelvic arteries and share their names.
The veins of the lower limb can be divided into two groups: the superficial and the deep veins. There are many anastomoses formed between the superficial and deep veins of the lower limb, called the communicating veins. The major deep veins of the lower limb continue as the pelvic veins.