1. Skin Hypodermis Skin Color Skin Function

2. Subcutaneous or Hypodermis Not part of the skin Between dermis and tissues below

3. Rich in Adipose tissue (subcutaneous fat) Subcutaneous injections

4. Skin Color Determined by amount of 1. Melanin 2. Carotene 3. Hemoglobin at surface

5. 1. Melanin Dark Brown pigment Produced by Melanocytes – Stratum Basale – Tyrosine → Melanin Enzyme Tyrosinase

6. Melanin Decreased Tyrosinase – Graying of Hair – White skin of elderly

7. Melanin Absence of Tyrosinase – Albinism (recessive)

8. Melanin Absence of Tyrosinase – Albinism

9. Melanin Melanocytes can group together – Results in ….

10. Melanin Freckles

11. Amount of Melanin Controlled by – Genes – Environment UV radiation

12. 2. Carotene Yellow-orange pigment Found in food products

13. 3. Hemoglobin Red Tint – Vessels dilate at surface - Embarrassment (nerves)

14. Skin Functions 1. Protection – Microorganism barrier – Water loss (keratin) – Chemicals (keratin)

15. Skin Functions – Physical damage (collagen fibers and desmosomes) – UV damage (melanin)

16. Skin Functions 2. Sensory – Pressure, touch, pain, and temperature

17. Skin Functions 3. Excretion – Salts and wastes (urea)

18. Skin Functions 4. Vitamin D production – UV light reaction –Important for calcium absorption in bones

19. Skin Functions 5. Immunity – Macrophages in tissue

20. Skin Functions 6. Temperature regulation – Release Heat Vasodilatation – Increase blood flow to dermis

21. Skin Functions 6. Temperature regulation – Conserve Heat Vasoconstriction – Decrease blood flow to dermis