Which layer of a blood vessel wall is the thickest and contains smooth muscle?Multiple choice question.tunica mediatunica externatunica interna

Answer to the Question

The thickest layer of a blood vessel wall that contains smooth muscle is the tunica media.

Explanation

1. Tunica Media: This is the middle layer of the blood vessel wall, primarily composed of smooth muscle and elastic fibers. It is responsible for regulating the diameter of the blood vessel, controlling blood flow and pressure.

2. Tunica Externa (Adventitia): This is the outer layer that provides structural support and protection. It's predominantly made of connective tissue and does not contain smooth muscle.

3. Tunica Interna (Intima): This is the innermost layer that lines the lumen of the blood vessel. It consists of endothelial cells and connective tissue but lacks smooth muscle.

Therefore, the correct answer is tunica media.