Artery ‒ Anatomy

An **artery** is a blood vessel that carries blood away from the heart. All arteries have relatively thick walls to withstand the high pressure of blood generated by the heart. Arteries larger than 10 mm in diameter are typically elastic, containing abundant fibers that allow them to expand with each surge of blood from the ventricles and recoil as the surge passes. The innermost layer, the tunica intima (or tunica interna), is composed of epithelial and connective tissue layers. The tunica media, the middle layer, consists of smooth muscle layers supported by connective tissue rich in elastic fibers, most of which are arranged in circular sheets. The outermost layer, the tunica externa (or tunica adventitia), is a substantial layer of connective tissue primarily composed of collagen fibers. In veins, the tunica externa also includes groups of smooth muscle fibers. *LICENSES AND ATTRIBUTIONS CC licensed content, Shared previously, Structure and Function of Blood Vessels, Authored by: OpenStax College. License: CC BY: Attribution. License Terms: Download for free at:http://cnx.org/contents/WNsszrPZ@4/Structure-and-Function-of-Bloo*