INBDE Practice Exam 2026 – Complete Study Guide

The tunica media is the correct answer because it is the middle layer of an artery responsible for maintaining and adjusting blood pressure. The tunica intima is the innermost layer, consisting of endothelial cells. The tunica adventitia is the outermost layer, providing structural support. The endothelium, while part of the tunica intima, is not a specific layer and is responsible for many functions such as regulating blood flow and maintaining blood vessel health. Therefore, it is thicker in arteries because of its smooth muscles and elastic fibers that allow it to adjust and regulate blood pressure.