Structure and Function of Arteries, Capillaries, and Veins. The walls of arteries and veins have three layers or tunics: 1  An outer layer (tunica adventitia) of connective tissue with collagen fibers. 2  A middle layer (tunica media) of circularly arranged smooth muscle and elastic fibers.
You might have heard that eating chocolate or greasy foods can cause acne, but these are both just myths. The truth is that food has little to do with breakouts. Acne occurs when the openings of hair follicles become blocked with oil secretions, dead skin cells and bacteria.
Does caffeine in tea cause acne? While weighing the question, can drinking tea cause acne, consider its caffeine content. Caffeine is a great energiser, but the downside is that it boosts your adrenalin and leaves you in a state of high stress , hyper in other words. High stress of course, is linked to acne. Caffeine causes sleeplessness as well.