Original: There are three major types of blood vessels : the arteries , which carry the blood away from the heart ; the capillaries , which enable the actual exchange of water and chemicals between the blood and the tissues ; and the veins , which carry blood from the capillaries back toward the heart .
Simplified: Blood vessels that take blood to the heart are veins . Capillaries are located between veins and arteries and they supply tissue with blood and oxygen .