Nikolas
Created page with "The body has both an external and internal surface. The external surface consists of skin and is very large, approximately 1.8 m2. The internal surface however, consists of mucosa and is 400 m2! The skin is a strong physical barrier, which nothing is supposed to leave (except sweat and oils). The mucosa however, must be somewhat permeable to allow the body to take up nutrients from food and oxygen from air. The immune system of the mucosa is therefore more highly special..."
