1. Looking Deeper Into the skin
Skin Proteins and Appendages

2. Skin Proteins Keratin – strengthens & waterproofs
Collagen – strengthens, helps in wound repair, provides structural support
Elastin – provides stretchiness

3. Skin Proteins Melanin – UV protection, skin color Freckles Sun spots
Vitiligo
Albinism

4. Skin Appendages - Glands
Sebaceous glands
Oil glands – secrete sebum
Softens & moisturizes skin, inhibits bacteria
Connected to hair follicles
Acne is inflamed sebaceous glands

5. Skin Appendages - Glands
Sudoriferous (sweat) glands:
Apocrine
Mainly in hairy places
Stimulated by stress/excitement
Possible pheromone source
Is main source of body odor when digested by bacteria
Eccrine
Found everywhere
Thermoregulation

6. Skin Appendages - Hair
Made of highly keratinized dead epithelial cells
Formed by follicle & nourished by dermal papilla
Functions
Arrector pili – attached muscles that cause goosebumps

7. Hair Structure Cuticle – protective outer layer
Cortex – largest area, filled with melanin
Medulla – center, can be hollow or filled with cells

8. Hair Growth Patterns Three main phases: Anagen – grows
Catagen – slows, ends when it stops
Telogen – rests, pushed out by new hair

9. Skin Appendages - Nails
Tightly packed keratinized cells
Grow from lower layer of epidermis
No pigment - colorless