Veins contain valves that primarily prevent the back-flow of blood. The media has circular smooth muscle, which is usually not prominent, except for the superficial veins of the legs. They have well developed longitudinal smooth muscle in the tunica adventitia.
Tunica Intima: Endothelial cells with a thin subendothelium of connective tissue and discontinuous elastic laminae.
They function to ‘conduct’ blood from the heart to regions of the body, where it can be distributed.Įlastic arteries include most of the named vessels surrounding the heart, such as the aorta and pulmonary arteries. These are the largest arteries found in the body, and are found closest to the heart. Fig 1.1 – The components of an artery wall.