tunica media

The tunica media, or middle coat, is made up principally of smooth (involuntary) muscle cells and elastic fibres arranged in roughly spiral layers. The outermost coat, or tunica adventitia, is a tough layer consisting mainly of collagen fibres that act as a supportive element. The large…

The tunica media, or middle coat, is thicker in arteries, particularly in the large arteries, and consists of smooth muscle cells intermingled with elastic fibres. The muscle cells and elastic fibres circle the vessel. In larger vessels the tunica media is composed primarily of elastic fibres.…

…intima; a middle layer, or tunica media; and an outer layer, or tunica adventitia. Each coat has a number of sublayers. The tunica intima differs from the inner layer of an artery: many veins, particularly in the arms and legs, have valves to prevent backflow of blood, and the elastic…