1. Integumentary System Functions:
Protect the body from infection and outside environment.
Maintains homeostasis.
Prevents the loss of water.
Produces vitamin D.
Eliminates waste (sweat)
Regulates body temperature.

2. Layer #1: Epidermis Part of your skin you can see.
Does NOT contain nerves or blood vessels.
Composed of dead skin cells that shed (about 9 lbs/per year).
Protects lower layer.
This layer contains melanin (pigments that give your skin its color and protects from UV light). More melanin = darker skin.

3. Layer #2: Dermis Contains: nerve endings (feeling)
sweat glands (waste)
oil glands (moisture)
hair (sense danger)
Some cells here also produce Vitamin D that helps with calcium uptake, to keep bones strong.

4. Layer #3:Subcutaneous
Made mostly of fat and helps your body stay warm and absorb shocks.
This layer is where you'll find the start of hair, too (follicles).