Both the Tunica Media and the Tunica Adventitia are Absent

Question

Both the tunica media and the tunica adventitia are absent in:
A)arteries.
B)veins.
C)capillaries.
D)both B and C.

Accepted Answer

Capillaries are the smallest blood vessels in which only a single layer of endothelial cells is present. They do not have a tunica media or adventitia. Arteries and veins have all three layers, with the tunica media being particularly thick in arteries to withstand high pressure.