–Vascular channels in which blood circulates throughout the body

–All blood vessels

▪Have a central opening or lumen

▪Are lined with a smooth layer of endothelium, also called the intima

Intima

Smooth lining of the blood vessel AKA endothelium

3 types of blood vessels

–There are three kinds of blood vessels, each of which performs a different function

▪Arteries carry blood away from the heart

▪Capillaries connect arteries and veins

▪Veins carry blood toward the heart

Vasoconstriction and vasodilation of the arteries are important ways in which the body regulates the blood pressure.