Functions of human skin. A)protection-physical chemical and infection. B)physiological-homeostasis of electrolytes water and protein. C)thermoregulation. D)sensation-specialised nerve endings. E)lubrication and waterproofing-sebum. F)immunological-langerhans cells lymphocytes and macrophages. G) vitamin D synthesis. H)body order-apocrine glands. I)psychological-Cosmetic.