3. Protection- mechanical, chemical, bacterial Body temperature regulation Prevent water loss Metabolic- synthesize vitamin D Cutaneous Sensation Blood reservoir Excretion Prevent UV damage

4. An organ, cells constantly dying and being replaced Facts: Weighs 9-11 lbs s.a. = 1.5-2m 2 1 cm 2 has 70 cm blood vessels, 55 cm nerves, 100 sweat glands, 15 oil glands, 230 sensory receptors New skin produced in 25-45 days

6. Keratinocytes (90%)- waterproofs & protects skin, nails, hair, stratum corneum Melanocytes (8%)- produce melanin Merkel Cells- slow mechanoreceptors Langerhans’ Cells- immunological defense

7. Stratum Corneum Stratum Lucidum Stratum Granulosum Stratum Spinosum Stratum Basale- (Germinativum)

9. Dermis

10. papillary dermis reticular dermis

11. a. Cellular Fibroblasts (synthesize collagen, elastin, and reticulin), histiocytes, endothelial cells, perivascular macrophages and dendritic cells, mast cells, smooth muscle, and cells of peripheral nerves and their end-organ receptors. b. Fibrous Collagen & reticulin - provide tensile strength Elastic fibers- provide for restoration of shape after a deformation c. Ground substance glycosaminoglycans: hyaluronic acid, chondroitin sulfate, and dermatan sulfate.

12. This layer contains adipose tissue and serves to attach the dermis to its underlying tissues. Hypodermis

13. Some variations in human skin color (Sub-Saharan African, Indian, Southern European, and Northwest European) Melanin Pigments: Eumelanin: Phaeomelanin > Eumelanin:Phaeomalanin- darker skin and hair color; < Eumelanin:Phaeomalanin- lighter skin and hair color Skin color due to: Melanin, Carotene & Hemoglobin

14. I -light skinned, burns easily, never tans II - light skinned, burns easily, tans some III - light skinned, burns occasionally, tans well IV - light skinned, tans well, rarely burns V - brown skinned (Asian, Indo-Asian, Chinese, Japanese), tans well, burns rarely, can sunburn after prolonged exposure to UVR VI - black skinned (Afro-Caribbean), deeply pigmented, can burn after prolonged exposure to UVR 25% US pop Human complexions are generally classified into six skin types:

15. Cyanotic Jaundice Erythema Pallor

16. Pigmentation levels usually increase with age. - exception: premature graying Normal pigmentation may be altered by genetic defects or by acquired diseases. -Hyperpigmentation- age spots -Hypopigmentation- vitiligo, albinism

17. External agents can also alter skin color. lightening agents carotene dyes Some internal compounds--such as the byproducts of hemoglobin metabolism--may color the skin. Sunless tanning

18. Malignant melanoma 2% of all cancers Risks: 1.Skin type 2.Sun exposure 3.Family history 4.Age 5.Immunological status A= asymmetry B= border C= color D= diameter Normal mole Melanoma

19. Sweat Glands Eccrine (merocrine) glands- sweat Apocrine glands- axillary & anogenital areas Ceruminous glands- ears canal Mammary glands- female reproductive glands Ceruminous glands Sweat glands

20. Sebaceous

21. Hair Sebaceous gland Hair shaft Hair root Hair bulb in follicle

22. Nail

23. 1 st Degree: epidermal damage Ex. sunburn 2 nd Degree: epidermis & upper dermis Ex. blisters 3 rd Degree: entire thickness of skin

25. Blood vessels dilate WBC & clotting agents released Scab forms

26. Granulation tissue forms Capillary beds invade clot Clean up begins

27. Scar area has contracted Epithelium regeneration begins

28. 1.In which lay of skin are blood vessels located? 2.Where does epithelium regeneration begin? 3.What color is a persons skin if they are cyanotic? 4.List the layer of the epidermis in order from top to bottom. 5.What is the primary tissue of the hypodermis? 30