Arteries and veins have distinct histological features. Arteries have thicker walls composed of three layers: the tunica intima, tunica media, and tunica adventitia. The tunica media is especially prominent, containing smooth muscle and elastic fibers to withstand high pressure. In contrast, veins have thinner walls, a larger lumen, and valves that prevent backflow of blood. Their tunica media has fewer smooth muscle cells, making them less rigid than arteries.
