Leg and abdomen arteries (red), coloured magnetic resonance angiography (MRA) scan. The abdominal portion of the aorta (top centre, white, the main body artery) has renal arteries branching off from it to supply the two kidneys (green, on each side) with oxygenated blood. Further down (upper centre) it splits to form the iliac arteries in the groin. These supply each leg with blood. As the external (main) arteries descend the leg, internal branches split off to supply blood to internal tissues and organs. The arteries between each split are named for the region of the leg: iliac (groin), femoral (thigh), popliteal (knee) and tibial (calf).