1. Skin Cell Types

2. Keratinocytes Keratin producing cells
Make up 90% of all epidermal cells

3. Melanocytes
Epidermal cells (~8%) which produce melanin

4. Langerhans cells
Participate in immune responses against microbes invading the skin

5. Merkel cells Least numerous epidermal cells, found in deepest layer
Function in sensation of touch

6. Meissner corpuscles
Receptors for fine touch located in dermal papillae of hairless skin

7. Thermoreceptors
Detect changes in temperature

8. Mechanoreceptors
Detect pressure, stretching, touch

9. Nociceptors
Detect pain, usually as a result of physical or chemical damage to skin

10. Pacinian corpuscles
Detect pressure

11. Fibroblasts
Immature cells that secrete fibers and the matrix in loose and dense connective tissue

12. Macrophages
Cells that remove foreign particles by engulfing them

13. Mast cells
Cells that secrete histamine which dilates blood vessels during inflammation

14. Adipocyte
Fat cell
Stores fat to be used for energy/insulation

15. Functions of the Skin Function Regulations of body temperature
Cells/structures maintaining homeostasis
Regulations of body temperature
High body temp – sweat  evaporates to cool
Changes in blood flow regulate as well
Sweat glands
Blood vessels

16. Function of the Skin Function Protection Stratified squamous cells
Cells/Structures maintaining homeostasis
Protection
From abrasion
From bacterial invasion
From dehydration
From UV radiation
Stratified squamous cells
Macrophages
Keratinocytes
Langerhans cells

17. Function of the Skin Function Sensation Mechanoreceptors Nociceptors
Cells/Structures maintaining homeostasis
Sensation
Detect stimuli
Mechanoreceptors
Nociceptors
Merkel cells
Meissner corpuscles
Thermoreceptors
Pacinian corpuscles

18. Function of the Skin Function Excretion Sweat glands
Cells/Structures maintaining homeostasis
Excretion
Small amounts of water, salts, etc
Sweat glands

19. Function of the Skin Function Immunity Macrophages Langerhans cells
Cells/Structures maintaining homeostasis
Immunity
Fight foreign invaders of the body
Macrophages
Langerhans cells

20. Function of the Skin Function Synthesis of vitamin D melanocytes
Cells/Structures maintaining homeostasis
Synthesis of vitamin D
Sun exposure initiates synthesis of vitamin D
melanocytes