1. S KIN AND BODY MEMBRANES

2. T HE SKIN Fun Facts: Avg. makes up about 9-11 lbs. or 7% of your weight Regenerates every 25-45 days Every minute you lose 30,000-40,000 dead skin cells

3. S KIN S TRUCTURE (EDH) Epidermis (epithelial) Dermis (fibrous) Hypodermis (subcutaneous – fat)

4. S KIN S TRUCTURE (EDH)

5. S KIN S TRUCTURE Epidermis—outer layer Stratified squamous epithelium

6. S KIN S TRUCTURE Dermis Dense connective tissue Not part of the skin Anchors skin to underlying organs Mostly adipose tissue (subcutaneous tissue)

7. 5 L AYERS OF THE E PIDERMIS (CLGSB) Stratum corneum Statum lucidum Stratum granulosum Stratum spinosum Statum basale

8. 5 L AYERS OF THE E PIDERMIS (CLGSB) Stratum basale

9. 5 L AYERS OF THE E PIDERMIS (CLGSB) Stratum spinosum

10. 5 L AYERS OF THE E PIDERMIS (CLGSB) Stratum granulosum

11. 5 L AYERS OF THE E PIDERMIS (CLGSB) Stratum lucidum

12. 5 L AYERS OF THE E PIDERMIS (CLGSB) Stratum corneum

13. NOTE: Thick skin- covers palms, fingertips, soles of feet Thin skin – covers rest of body missing stratum lucidum and sometimes stratum granulosum

15. M ELANIN Pigment produced by melanocytes Amount of melanin produced depends upon genetics and exposure to sunlight

16. M ELANIN – S KIN C OLOR GENETICS is the key factor Quantity of melanin (yellow to reddish- brown to black) protects skin from UV radiation Melanocytes use enzyme tyrosinase to convert tyrosine into dark brown melanin pigment, albinos lack DNA code to make tyrosinase

17. A LBINISM IN H UMANS

18. M ELANIN – S KIN C OLOR Sunlight increases melanin production by the release of hormones freckles or moles are accumulations of melanin other pigments such as carotene or hemoglobin contribute to skin color

19. M ELANIN – S KIN C OLOR Prolonged exposure causes substantial melanin buildup which helps protect the DNA of viable skin cells from UV radiation by absorbing the light and dissipating the energy as heat

20. D ERMIS Two layers Papillary layer (upper dermal region) Reticular layer (deepest skin layer)

21. D ERMIS Papillary layer (upper dermal region)

22. D ERMIS Reticular layer (deepest skin layer)

23. D ERMIS O VERVIEW Collagen fibers give skin its toughness Elastic fibers give skin elasticity Blood vessels play a role in body temperature regulation

24. S KIN A PPENDAGES Glands Hair Hair follicles Nails

25. S EBACEOUS GLANDS Produce oil Glands are activated at puberty

26. S EBACEOUS GLANDS

27. S WEAT GLANDS Produce sweat Widely distributed in skin Two types Eccrine Apocrine

28. S WEAT GLANDS

29. H AIR Produced by hair follicle Consists of hard keratinized epithelial cells Melanocytes provide pigment for hair color

30. H AIR Hair follicle- shaft, follicle (root) Growth- 4 in./year or 2 mm/week

31. H AIR Associated hair structures Hair follicle Arrector pili muscle Sebaceous gland Sweat gland

35. N AILS Scale-like modifications of the epidermis

36. N AILS Consists of: free edge Body Root Cuticle Lunula Growth- 0.5 mm/week

37. N AILS

38. Did you know that your fingernails grow much faster than your toe nails? 3-4 times faster!

39. S KIN I NFECTIONS AND A LLERGIES Contact dermatitis Exposures cause allergic reaction Cold sores Caused by virus Impetigo Caused by bacterial infection Psoriasis Cause is unknown Triggered by trauma, infection, stress

40. S KIN I NFECTIONS AND A LLERGIES

41. B URNS Burns Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals

42. B URNS Associated dangers

43. R ULE OF N INES Way to determine the extent of burns Body is divided into 11 areas for quick estimation Each area represents about 9% of total body surface area

44. R ULE OF N INES

45. S EVERITY OF B URNS First-degree burns Second-degree burns Third-degree burns

46. S EVERITY OF B URNS

47. C RITICAL B URNS Burns are considered critical if Over 25% of body has second-degree burns Over 10% of the body has third-degree burns There are third-degree burns of the face, hands, or feet