Aorta, the great artery through which the heart forces blood to the entire body. In the human body it springs from the left ventricle, and arches backward to the spinal column, thence downward. From the very beginning the aorta begins to give off small arteries; first, those that supply the heart itself, then from the top of the arch, the arteries that supply the head, neck, and arms. On its downward descent the aorta gives off branches that supply the body with arterial blood, dividing finally into two large arteries, one for each leg. All arteries save that which carries blood to the lungs for purification are branches of the aorta. The aorta of an average person is about half an inch in diameter. It is considered that all the blood of the body is pumped through the aorta on an average once each twenty-three minutes. See HEART; BLOOD.