The coronary artery provides blood supply to the walls of the ventricles and the right atrium of the heart. It is an example of muscular artery.
Tunica Intima - inner layer composed of the endothelium, subendothelial connective tissue, and the internal elastic lamina. As seen in this specimen, the tunica intima progressively thickens by increasing amounts of smooth muscle and elastic tissue with aging.
Tunica Media - middle layer composed mostly of circumferentially arranged smooth muscle.