1. Integumentary System Epidermis Skin Color & Cancer Dermis
Hair, Nails & Glands
Temperature Regulation
Wounds & Healing

2. The Skin & Its Tissues

3. View of Skin & Underlying Tissues

4. Inhabitants of the Epidermis

5. Epidermal Layers - Blisters, Calluses &Psoriasis
Composed primarily of keratinized stratified squamous
epithelial cells -- consisting of 4-5 layers:
stratum corneum: outermost layer, keratinized dead epithelium
stratum lucidum: layer found in thickest areas of skin
stratum granulosum: 3-5 layers of flattened granular cells, developing keratin fibers
stratum spinosum: multiple layers of cells
stratum basale: deepest layer of single cuboidal or columnar cells, also contains melanocytes
- Blisters, Calluses &Psoriasis

6. Melanocytes Specialized cells in epidermis produce melanin
dark pigment providing skin color
cells lie in stratum basale
cytocrine secretions: cellular extension
absorbs UV radiation in sunlight
protects dermis

7. Skin Color - Genetics, Environment & Physiology:
# of melanocytes - difference in kind, amount & size
sunlight, UV light, etc.
blood in dermis, blood vessels, freckles & moles
other pigments - carotinoids
jaundice – liver disorder

8. Skin Cancer http://www.skincancer.org
Squamous cell Basal cell carcinoma Malignant melanoma
carcinoma

9. Dermis: 2 layers
Dense CT: composed of collagen, elastin & reticular fibers:
unevenness b/t layers (dermal papilae) form fingerprints (epidermal ridges)
delivers nutrients & O2 to epidermal cells
binds epidermis to underlying tissue
contains muscle fibers (facial expressions)
nerve cells are distributed throughout (e.g., Meissner’s & Pacinian corpuscles)
hair follicles, sweat & sebaceous glands

10. Dermis

11. Hair & Nails are Derivatives of Skin
Hair: protective function, found on most skin surfaces consisting of epidermal cells & keratin
hair follicle: structure hair develops from
hair root: portion below skin surface
hair shaft: extends away from skin surface
hair color: epidermal melanocytes
arrector pili muscle: goose bumps
sebaceous glands: associated w/ hair follicles, lubricate hair & skin
androgenic alopecia

12. Hair Follicle

14. Nails: Protect Ends of Fingers & Toes
Specialized epithelial cells that keratinize; consist of nail plate & nail bed
Lunula (1/2 moon shape region): active growing area of nail
What can nail appearance indicate?

15. Skin Glands Sweat glands: Sebaceous glands:
- assoc. w/ hair follicles,
secrete sebum - oils hair,
lubricates skin & prevent
water loss
- acne vulgaris
Sweat glands:
Eccrine: deep in dermis or subcutaneous layer, odorless secretions, function in thermoregulation
Apocrine: found near hair follicles, in axillary regions, released during pain, fear & stress or sexual arousal
- Ceruminous & mammary glands

16. Eccrine & Apocrine Sweat Glands

18. Temperature Regulation
Homeostatic mechanism
- receptor
- control center
- effectors

19. Body Temperatures Under Varying Conditions
heat exhaustion
heat stroke
fever
hypothermia

20. Wounds & Healing Inflammation: normal response to injury or stress
Laceration: break in the skin
epidermal cut: epithelial cells around injury proliferate & newly formed cells fill in
dermal cut: clot forms (RBC, platelets, proteins)
growth factors: induce migration of fibroblast & macrophages
smooth muscle & fibroblasts stimulate tissue repair

21. Steps of Tissue Repair