Anatomy - Arteries and Veins

Arteries: Elastic tubes which carry the blood away from the heart to the tissues. Two great trunks, the aorta and pulmonary artery, leave the heart and divide again and again until they become minute vessels to which the name of arterioles is given.

Veins: Blood vessels which return the blood from the capillaries toward the heart. As they approach that organ they join together to form larger and larger trunks.