What is the function the tunica media and tunica adventitia?

The tunica media is the middle layer of blood vessel walls, primarily composed of smooth muscle and elastic fibers, which allows for the regulation of blood vessel diameter and blood pressure through contraction and relaxation. The tunica adventitia, the outer layer, provides structural support and stability to the blood vessel, anchoring it to surrounding tissues and containing larger blood vessels and nerves that supply the vessel itself. Together, these layers play crucial roles in maintaining vascular function and integrity.