How many layers does an arterial wall possess?

An arterial wall consists of three layers:

1. Tunica Intima: The innermost layer of the arterial wall is called the tunica intima. It is made up of a single layer of endothelial cells that lines the lumen of the artery. These endothelial cells are responsible for maintaining blood flow and regulating vascular tone.

2. Tunica Media: The middle layer of the arterial wall is called the tunica media. It consists of multiple layers of smooth muscle cells, elastic fibers, and collagen fibers. The smooth muscle cells are responsible for controlling the diameter of the artery by constricting or relaxing, thus regulating blood flow and blood pressure.

3. Tunica Adventitia: The outermost layer of the arterial wall is called the tunica adventitia. It is composed of connective tissue, fibroblasts, and collagen fibers that provide structural support, protection, and nourishment to the artery.