1. Integumentary System Kristen Cianci

2. What is it?  Includes skin, hair, and nails  Body’s largest organ  15% of total body weight

3. Functions  First defense against bacteria, viruses, and other pathogens  Eliminates waste through perspiration  Protects us from harmful ultraviolet radiation  Guards against sunburn

4. The 3 Layers  Epidermis -has no blood vessels -consists of keratinocytes

5. The 3 Layers  Dermis -contains two layer = provides elasticity -ending sight for blood vessels and nerves -contains sweat glands, lymph vessels, and oil glands

6. The 3 Layers  Hypodermis -insulate and cushion organs -stores fat -blood vessels, lymph vessels, nerves, and hair follicles run through here

7. Diseases  Acne- caused by increased levels of androgens  Alopecia Areata- attacks hair follicles  Athlete’s Foot- common fungus infection between the toes  Dermatitis- inflammation, such as poison ivy  Psoriasis- causes skin cells to mature quickly, backup of cells on surface  Skin cancer- epidermis stops producing keratin