SkinSlide 2PowerPoint PresentationSlide 4SkinSlide 6Slide 7Skin•Outer covering containing and providing barrier•Barrier – mechanical between external environment and underlying tissues•Barrier – defense mechanisms and separation / immunity ideas•Two layers – epidermis and dermisSkin•Epidermis – numerous layers of epithelial cells–Inner epidermis – living, dividing–Outer epidermis – dead, flattened•No direct blood supply–Nourished by diffusion of nutrients from extensive vascular system in underlying dermisSkin•Outer layer – cells far from vascular layer•Keratin filaments connect outer ‘dead’ cells and as outer cells fuse with keratin connectors to form a keratinized layer–Constantly replaced from inner dermal cells–Thickness and rate of cell division depends on location in body–Thick where most pressure/abrasion – bottom of feet, elbowSkin •Dermis – connective tissue layer with elastin (stretch) and collagen (strength)•Vessels – supply tissues–Also – temperature regulation–Volume of blood through the vessels between parasympathetic and sympathetic controls heat exchangeSkin•Exocrine glands – invaginations of the epidermis into underlying dermis–Sweat glands – release NaCl solution through sweat pores and evaporation cools skin and assists in temperature regulation–Sebaceous glands – release sebum (oily secretion) Assists in ‘waterproofing’ external epidermis and prevents drying/cracking – insufficient sebum = chapped (cold and constriction of tissue and release of