Answer:
The middle layer of an artery is called "Tunica media".
Step-by-step explanation:
It is composed of smooth muscle cells and elastic fibers. This layer is responsible for regulating the diameter of the artery, which, in turn, controls blood flow and blood pressure. The smooth muscle cells in the tunica media allow the artery to contract and relax, adjusting its size in response to the body's needs. The elastic fibers provide flexibility and help maintain the structural integrity of the artery. The tunica media is a crucial component in the structure and function of arteries within the circulatory system.