2.  Secrete onto skin  About 2-5 million throughout the body  Lots in palms and soles of feet  Secretion:  99% water  Electrolytes  Urea  Cools surface and lowers body temp  Blood vessels dilate  Reddens skin  Negative Feedback System

4.  Protect tips  Nail body—what you see  Nail bed—skin under nail body  Nail root—produces nail  Pink color due to blood vessels

6.  Bleeding at injury  Mast cells trigger inflammatory response  Scab forms  Phagocytes remove debris  Clot forms  Epidermal cells form  Scab falls off  New epidermis underneath

11.  First Degree  Killed superficial epidermis  Injured deep epidermis  Inflamed, tender

12.  Second Degree  Killed superficial and deep epidermis  Injured superficial dermis  Blisters, very painful

13.  Third Degree  Killed all epidermal and dermal cells  Injured hypodermis and organs  Charred  No sensation

14.  Skin injuries and infections common  Stem cell activity decreases  Epidermis thins  Immune system less sensitive  Increased rate of infection  Muscle and bone weaken  Due to decreased vitamin D production  Sensitive to sun  Due to decreased melanin production  Skin pales

15.  Dry, scaly skin  Decreased sebum and perspiration  Hair thins and changes color  Follicles stop  Decreased melanocytes  Sagging and wrinkling  Decreased elastic fibers  Ability to lose heat decreases  Reduced blood supply  Slow skin repair