2. THE SKIN Function –Protective covering Bacterial infection Physical trauma –Receptors Touch, pressure, pain, heat and cold –Vitamin D production UV light –Regulation of body temperature Dilation or constriction of blood vessels Sweat glands

3. Epidermis Dermis Hypodermis (Subcutaneous Layer) SKIN REGIONS

4. SKIN REGIONS Epidermis –Protective outer epithelial layer –Avascular

5. Dermis  Tough, fibrous connective tissue layer  Largest region of the skin  Vascular Dermis  Tough, fibrous connective tissue layer  Largest region of the skin  Vascular SKIN REGIONS

6. Hypodermis  Region just deep to the dermis  Adipose and areolar C.T.  Anchors the skin Hypodermis  Region just deep to the dermis  Adipose and areolar C.T.  Anchors the skin SKIN REGIONS

7. Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale LAYERS of the EPIDERMIS

8. THE EPIDERMIS Definition –Keratinized, stratified squamous E.T. Layers –Five layers in thick skin –Four in all other skin

9. THE EPIDERMIS Cells –Keratinocytes Most numerous cell type keratinProduce the protein keratin for waterproofing and protection Replaced every 25 to 45 days

10. EPIDERMAL LAYERS Stratum Basale –Deepest layer –Attached to dermis –Single layer of cuboidal keratinocytes –Mitotic layer melanocytes –Contains melanocytes Produce the pigment melanin Merkel’s discs = –Contains Merkel’s discs = Sensory nerve endings Pressure

11. melanocytes EPIDERMAL LAYERS: Stratum Basale

12. EPIDERMAL LAYERS Stratum Spinosum  Several layers of keratinocytes with a “spiny” appearance  Scattered melanin granules  Langerhan cells  Langerhan cells = macrophages Stratum Spinosum  Several layers of keratinocytes with a “spiny” appearance  Scattered melanin granules  Langerhan cells  Langerhan cells = macrophages

13. EPIDERMAL LAYERS: Stratum Spinosum

14. EPIDERMAL LAYERS Stratum Granulosum  Thin region of dark- staining cells keratohyaline  Flat cells with keratohyaline granules  Cells above are dead Stratum Granulosum  Thin region of dark- staining cells keratohyaline  Flat cells with keratohyaline granules  Cells above are dead

15. EPIDERMAL LAYERS: Stratum Granulosum

16. EPIDERMAL LAYERS Stratum Lucidum  Only present in thick skin  Thin, translucent layer of dead keratinocytes Stratum Lucidum  Only present in thick skin  Thin, translucent layer of dead keratinocytes

17. EPIDERMAL LAYERS: Stratum Lucidum

18. EPIDERMAL LAYERS Stratum Corneum  Outer, loose layer of dead, flaky cells  Protects skin from: J Abrasion or penetration Stratum Corneum  Outer, loose layer of dead, flaky cells  Protects skin from: J Abrasion or penetration

19. EPIDERMAL LAYERS: Stratum Corneum

20. THE DERMIS Definition  A thick, flexible C.T. layer  Rich in nerve fibers  Very vascular Layers  Papillary layer  Reticular layer Definition  A thick, flexible C.T. layer  Rich in nerve fibers  Very vascular Layers  Papillary layer  Reticular layer

21. THE DERMIS

22. Papillary Layer  Loosely woven  Highly vascular  Contains: J Dermal papillae J Meissner’s corpuscles Detect touch J Free nerve endings Detect pain  Larger dermal folds form ridges = fingerprints J On palms of hands and soles of feet Papillary Layer  Loosely woven  Highly vascular  Contains: J Dermal papillae J Meissner’s corpuscles Detect touch J Free nerve endings Detect pain  Larger dermal folds form ridges = fingerprints J On palms of hands and soles of feet dermal papillae Meissner’s corpuscle LAYERS of the DERMIS

23. dermal papilla epidermal peg STRUCTURES of the DERMIS

24. Meissner’s Corpuscle STRUCTURES of the DERMIS

25. Reticular Layer  Makes up 80% of the dermis  Dense, irregular C.T. rich in collagen  Contains: J Hair follicles J Sebaceous glands J Blood vessels and nerves J Pacinian corpuscles J Pacinian corpuscles in deep regions Detect crude touch; deep pressure Reticular Layer  Makes up 80% of the dermis  Dense, irregular C.T. rich in collagen  Contains: J Hair follicles J Sebaceous glands J Blood vessels and nerves J Pacinian corpuscles J Pacinian corpuscles in deep regions Detect crude touch; deep pressure Pacinian corpuscle LAYERS of the DERMIS

26. Pacinian Corpuscle STRUCTURES of the DERMIS

27. Three Pigments Determine Skin Color  Melanin J Brown to black pigment J Prevents UV damage  Carotene J Yellowish, orange pigment J Noticeable in the palms and soles  Hemoglobin J Red pigment when oxygenated J Gives the skin a bluish or gray appearance when poorly oxygenated (cyanosis) Three Pigments Determine Skin Color  Melanin J Brown to black pigment J Prevents UV damage  Carotene J Yellowish, orange pigment J Noticeable in the palms and soles  Hemoglobin J Red pigment when oxygenated J Gives the skin a bluish or gray appearance when poorly oxygenated (cyanosis) SKIN COLOR

28. Definition  Keratinized cells produced by hair follicles Hair Structure  Papilla J At the hair base J Supplies the cells with nutrients  Arrector pili J Smooth muscles J Pull hair upright Definition  Keratinized cells produced by hair follicles Hair Structure  Papilla J At the hair base J Supplies the cells with nutrients  Arrector pili J Smooth muscles J Pull hair upright APPENDAGES of the SKIN: Hair and Hair Follicles

29. papilla epidermal tissue Hair and Hair Follicles

30. Arrector Pili Muscle Hair and Hair Follicles

31. Types of Hair  Vellus Hair J Soft body hair of children and adult females  Terminal Hair J Coarse, longer growing hair J Found: Eyebrows, head, armpits, pubic regions of adults Face, chest, arms and legs of adult males Types of Hair  Vellus Hair J Soft body hair of children and adult females  Terminal Hair J Coarse, longer growing hair J Found: Eyebrows, head, armpits, pubic regions of adults Face, chest, arms and legs of adult males APPENDAGES of the SKIN: Hair and Hair Follicles

32. Definition  Epidermal modifications J Protects the dorsum of the fingers and toes keratin J Contain keratin Definition  Epidermal modifications J Protects the dorsum of the fingers and toes keratin J Contain keratin APPENDAGES of the SKIN: Nails

33. Two Types:  Eccrine Sweat Glands J Open to skin surface J Regulation of body temperature Two Types:  Eccrine Sweat Glands J Open to skin surface J Regulation of body temperature Merocrine sweat gland APPENDAGES of the SKIN: Sudoriferous (Sweat) Glands

34.  Apocrine Sweat Glands J Open into hair follicles in anal, groin and axillary region J Active at puberty J Not important in thermoregulation J Active during stress  Apocrine Sweat Glands J Open into hair follicles in anal, groin and axillary region J Active at puberty J Not important in thermoregulation J Active during stress Apocrine sweat gland APPENDAGES of the SKIN: Sudoriferous (Sweat) Glands

35. Sudoriferous (Sweat) Glands

36. Definition  Modified sweat glands J Within breasts J Produce milk following childbirth Definition  Modified sweat glands J Within breasts J Produce milk following childbirth mammary glands APPENDAGES of the SKIN: Mammary Glands

37. Definition  Simple alveolar glands found all over the body except on the palms and soles J Near hair follicles sebum J Secretes sebum Definition  Simple alveolar glands found all over the body except on the palms and soles J Near hair follicles sebum J Secretes sebum Sebaceous gland APPENDAGES of the SKIN: Sebaceous (Oil) Glands

38. Sebaceous (Oil) Glands

39. Hyperthermia Hyperthermia  An abnormally high body temperature J Can result in: Heat exhaustion (headache, vomiting, and tiredness) Heat stroke (dizziness, confusion, delusions) Increased fluid intake and possible medical care are needed in both cases J Fever Hyperthermia brought on by illness Body’s attempt to fight off infection Hyperthermia Hyperthermia  An abnormally high body temperature J Can result in: Heat exhaustion (headache, vomiting, and tiredness) Heat stroke (dizziness, confusion, delusions) Increased fluid intake and possible medical care are needed in both cases J Fever Hyperthermia brought on by illness Body’s attempt to fight off infection SKIN DISORDERS

40. Hypothermia Hypothermia  An abnormally low body temperature J Results in: Shivering, incoherent speech and lack of coordination Body functions slow and death occurs when metabolism stops completely Person must be warmed immediately Hypothermia Hypothermia  An abnormally low body temperature J Results in: Shivering, incoherent speech and lack of coordination Body functions slow and death occurs when metabolism stops completely Person must be warmed immediately SKIN DISORDERS

41. Skin Cancer Skin Cancer  Squamous cell carcinoma and basal cell carcinoma J Most common J Likely caused by sun exposure J Surgical removal is the standard treatment  Melanoma J Arises from melanocytes J Can metastasize Skin Cancer Skin Cancer  Squamous cell carcinoma and basal cell carcinoma J Most common J Likely caused by sun exposure J Surgical removal is the standard treatment  Melanoma J Arises from melanocytes J Can metastasize SKIN DISORDERS

42. Basal Cell Carcinoma Squamous Cell Carcinoma Malignant Melanoma SKIN CANCER

43. Burns Burns  Factors affecting burn severity J Depth of burn J Extent of area burned  Classification of burns J 1 st degree burns Epidermis is burned: redness and pain Damaged skin peels off Burns Burns  Factors affecting burn severity J Depth of burn J Extent of area burned  Classification of burns J 1 st degree burns Epidermis is burned: redness and pain Damaged skin peels off SKIN DISORDERS

44. Burns Burns  Classification of burns J 2 nd degree burns Extends through epidermis and part of the dermis Results in redness, pain and blisters May result in scarring Burns Burns  Classification of burns J 2 nd degree burns Extends through epidermis and part of the dermis Results in redness, pain and blisters May result in scarring SKIN DISORDERS

45. Burns Burns  Classification of burns J 3 rd degree burns Entire thickness of skin is burnt Blood vessels, sweat glands, and other skin accessories are also burnt Fluid and heat loss and bacterial infection Skin grafting required Survival chances are not good if large area Burns Burns  Classification of burns J 3 rd degree burns Entire thickness of skin is burnt Blood vessels, sweat glands, and other skin accessories are also burnt Fluid and heat loss and bacterial infection Skin grafting required Survival chances are not good if large area SKIN DISORDERS

46. 2 nd Degree Burn 3 rd Degree Burn 1 st Degree Burn BURNS