Medium muscular arteries are composed of a tunica media that contains mostly smooth muscle fibers. This characteristic allows these vessels to regulate their diameter and control the flow of blood to different parts of the body. Examples of medium muscular arteries are most of the named arteries, including the femoral, axillary, and radial arteries.
Small arteries and arterioles control the filling of the capillaries and directly contribute to the arterial pressure in the vascular system.
Veins also are subdivided into three classes.