Describe the general structure of the venous wall.

Tunica intima: luminal layer consisting of a single thickness of endothelial cells, similar in composition to the arterial intimal layer
Tunica media: thickest layer of the vessel wall, consisting of smooth muscle cells. Contains far fewer smooth muscle cells than the tunica media of arteries, making veins thinner and more flaccid than arteries
Tunica adventitia: outermost layer, connective tissue sheath; similar in composition to arterial adventitial layer