1. CHAPTER 5 Appendages of the Skin

2. Hair Body covered with millions of hairs a. follicles – most are present at birth b. hair papilla – hair growth begins here (base of follicle) c. arrector pili – involuntary muscle a. contract when frightened or cold b. pulls and makes hair go up and skin come down c. “goose pimples”

3. Receptors Sense organ in the skin (touch, pressure, pain, and temperature) 1. Meissners corpuscle – detects light touch – close to surface 2. Pacinian corpuscle – detects pressure on skin surface – deep in dermis 3. Free nerve endings – detect pain 4. Krause end bulbs – sensations of touch, low frequency vibrations, and possibly cold.

4. Nails Produced by cells in the epidermis Cells filled with keratin and become hard and plate-like

5. Eccrine Apocrine More numerous – over total body surface Sweat assists with waste elimination and temperature regulation Armpit and around genitals Larger than eccrine – give off a thicker secretion Odor caused by bacteria decomposing on the skin Begin function at puberty. Suboriferous (Sweat) Glands

6. Sebaceous Glands (oil glands) secrete oil for hair and skin secretion is called sebum prevents drying and cracking of the skin increases during adolescence forms pimples and blackheads