2. INTEGUMENTARY SYSTEM

3. Includes skin and all accessory organs - hair, nails and a variety of glands (sweat and oil); single largest organ in the body FUNCTIONS: 1. Protection - most important function; especially from ultraviolet radiation 2. Regulate body temperature 3. Remove wastes from the body 4. Barrier against infection and injury

4. INTEGUMENTARY SYSTEM Skin is composed of two MAIN layers: 1. Epidermis - outermost cells of skin; undergo rapid cell division (mitosis) 2. Dermis - inner layer of skin; contains blood vessels, nerve endings, glands, sense organs, smooth muscle and hair follicles 3. Hypodermis - below the dermis (layer of fat and connective tissue); not a main layer

5. INTEGUMENTARY SYSTEM ACCESSORY ORGANS: 1. Hair - produced by cells at base of hair follicle; used for protection and warmth 2. Nails - grow from nail root located near tip of fingers and toes; for protection 3. Sweat/Oil Glands - sweat glands - regulate body temperature and remove wastes; oil glands - keeps skin flexible and waterproof

7. Picture of Skin A = Epidermis B = Dermis C = Hypodermis D = Sweat Gland E = Hair Follicle F = Sebaceous (Oil) Gland G = Hair E G F