The common iliac artery originates from the abdominal aorta, the main blood vessel in the abdominal area. Both the aorta and the systemic arteries are part of the systemic circulatory system, which carries oxygenated blood from the heart to the other areas of the body and back.
The aorta ends at the fourth vertebra of the lumbar spine. There it divides into the right and left common iliac arteries. These two arteries travel down and to each side of the body for about five centimeters towards the edges of the pelvis. They then each split again into internal and external iliac arteries at the pelvic inlet, the area where the abdomen ends and the pelvis begins.
The internal iliac artery provides blood to the pelvic organs including the urinary bladder, the man's prostate gland, and the woman's uterus and vagina. The external iliac artery provides the main blood supply to the leg. It becomes the femoral artery and branches off as the popliteal artery and the anterior and posterior tibial arteries. The femoral artery supplies blood to the thigh, the popliteal artery supplies the knee area, and the anterior and posterior tibial arteries supply the area below the knee, including the feet and toes.
The common iliac artery is a paired structure, meaning there is one on the right and one on the left of the body.