Artery

The largest arteries which leave the heart are the aorta and the pulmonary artery; both spring from the base of the heart iny front. They branch and anastomose to a large extent. The contractility of the arteries forces the blood to the extremities from the heart, the valves of which prevent its return. The prominent difference between blood drawn from the arteries and that from the veins is to be found in the bright scarlet eolor of the former and the dark red, almost black, of the latter. |