How many layers of tissue does an artery have?

An artery consists of three distinct layers of tissue, which are critical for its function and structure. The innermost layer is the tunica intima, made up of endothelial cells that provide a smooth surface for blood flow and regulate the interaction between the bloodstream and the vessel wall. The middle layer, known as the tunica media, contains smooth muscle and elastic fibers, which allow arteries to withstand and regulate the pressure of the blood flowing through them by constricting or dilating. The outer layer, or tunica externa (also called tunica adventitia), is composed of connective tissue that provides additional support and flexibility to the artery.

Understanding the anatomy of arteries and their three-layer structure is essential for recognizing how they function within the circulatory system. This layered organization is critical for maintaining blood pressure, regulating blood flow, and ensuring that arteries can adapt to the varying demands of the body.