Arteries carry blood away from the heart. They are subdivided into the elastic arteries that are close to the heart, muscular arteries that distribute blood to the tissues, and the small arterioles that regulate blood pressure. Elastic arteries include the major arteries, such as the aorta and its branches, that expand and recoil to maintain blood flow during diastole (when the heart is not contracting).
Distribution, or muscular, arteries aplit off from the major arteries and travel to the tissues. They have smooth muscles cells that stretch and contract, damping the pulsatile flow caused by the beating of the heart. They give off arterioles, which have smooth muscle cells that control the diameter of the blood vessel. In this way, arterieoles regulate peripheral resistance to blood flow and contribute to control of blood pressure.
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