False-colour artwork showing the human circulation, as depicted in a standing human figure. The major branches of arteries & veins are shown, as are the heart, lungs and kidneys. The great vessels, the aorta and vena cava, can be seen running in parallel down the body to divide into the iliac arteries & veins that serve the legs. The pulmonary circulation (the blood supply to the lungs) and the subclavian arteries & veins (serving the arms) are also prominent.