How many layers of tissue are present in an artery?

An artery is composed of three distinct layers of tissue, which is why the answer is three. These layers are known as the tunica intima, tunica media, and tunica externa.

The tunica intima is the innermost layer, consisting of a smooth endothelial lining that helps reduce friction as blood flows through the artery. The tunica media is the middle layer, primarily composed of smooth muscle and elastic fibers, allowing the artery to maintain blood pressure and regulate blood flow through contraction and relaxation. Finally, the tunica externa, or adventitia, is the outer layer made of connective tissue that provides support and structure to the artery while anchoring it to nearby tissues.

Understanding the structure of arteries, including their three-layer composition, is crucial for anyone studying anatomy or involved in medical coding, as it provides foundational knowledge for cardiovascular-related diagnoses and treatments.