The tunica media contains a circular layer of smooth muscle cells that contract and relax in vasoconstriction and vasodilation, respectively.
These structures are lined by the tunica intima, tunica media, and tunica adventitia. The tunica media contains a circular layer of smooth muscle cells that contract and relax in vasoconstriction and vasodilation, respectively. One subset of these structures is inflamed in phlebitis and contains valves that fail to function in their "varicose" variety, while a second subset includes the aorta. For 10 points, name these structures through which blood flows, which include capillaries, arteries, and veins.
These structures are lined by the tunica intima, tunica media, and tunica adventitia.
blood {vessels} [prompt on {veins}; prompt on {arteries}]