characteristics of blood vessels
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.hen blood vessels connect to form a region of diffuse vascular supply it is called an anastomosis (pl. anastomoses). Anastomoses provide critical alternative routes for blood to flow in case of blockages. There is a layer of muscle surrounding the arteries and the veins which help contract and expand the vessels.