Which Blood Vessel Muscle Layer is Usually Thicker in the Arteries

Question

Which blood vessel muscle layer is usually thicker in the arteries than in veins?
A) tunica media
B) tunica intima
C) tunica externa
D) endothelium

Accepted Answer

The tunica media, which is the middle layer of blood vessels that is composed of smooth muscle cells and elastic fibers, is usually thicker in arteries than in veins. This allows arteries to expand and contract to manage blood pressure and flow. In contrast, veins have thinner tunica media, as they do not need to undergo as much pressure regulation.