1. The Skin
Ch 14 Sect 3

2. Functions of the Skin
Integumentary System includes the external coverings of the body: skin, hair and nails.
Skin is the largest organ of your body.
Skin protects your muscles and bones from the external environment.
It keeps your body from drying out.
Protects the cells and tissue from damage.
First line of defense.

3. Sensory Response & Temperature Regulation
Skin has sensory receptors that detect texture, temperature and sense pain.
The more sensory receptors in an area the more sensitive it is.
Skin helps control body temp.
When exercising, the body sweats and the sweat is released from pores (lowers temp.)
Releasing thermal energy from blood vessels lowers temp.

4. Vitamin D Production & Elimination
Skin makes Vitamin D when exposed to sunlight.
Vitamin D helps absorb calcium & phosphorous (bone growth).
Skin eliminates wastes : water, salts, and other waste products through sweat.

5. Structures of the Skin
Epidermis is the outermost layer of the skin (tough, thin). Melanin (sun absorbing pigment) production.
Dermis is a thick skin layer that gives skin strength, nourishment, and flexibility. (contains sweat glands, blood vessels, nerves, hair follicles and muscles).
Fatty Layer insulates the body, acts as a protective padding and stores energy.

7. Skin Injuries and Repair
Bruises is an injury where blood vessels in the skin are broken, but the skin is not cut or opened.

8. Cuts & Burns
Cuts occur when the skin has broken and cuts often cut blood vessels too. Scabs form to prevent dirt and other substances from entering the body.
Burns are caused by touching extremely hot or cold objects, chemicals, radiations, electricity, or friction.

11. Healthy Skin & Homeostasis
Skin needs to be protected from ultraviolet rays (sun). Ex. Wrinkles, dry skin and skin cancer
Eating a balanced diet helps keep skin healthy.
Skin helps the body maintain homeostasis by producing Vitamin D, and protects the body from outside substances.
Regulates the body’s internal environment.
Skin works with the nervous and muscular system to react to stimuli.