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.
Here, 7 foods that can make acne worse. Because of recent research on diet and acne, the American Academy of Dermatology now says there may be a link between milk consumption and breakouts. Blame the hormones in dairy, says Dr. Frank Lipman, an integrative and functional medicine physician and the founder