1. CHAPTER 6

2. INTEGUMENTARY SYSTEM SKIN Largest organ by weight ACCESSORY STRUCTURES

3. SKIN FUNCTIONS: MAINTAIN HOMEOSTASIS PROTECTIVE COVERING PREVENT WATER LOSS REGULATE BODY TEMPERATURE SENSE RECEPTORS SYNTHESIZES CHEMICALS IMMUNE SYSTEM CELLS EXCRETES SOME WASTE

4. CUTANEOUS MEMBRANE EPIDERMIS STRATIFIED SQUAMOUS EPITHELIUM DERMIS THICKER CONNECTIVE TISSUE: DENSE IRREGULAR; AREOLAR; SMOOTH MUSCLE; NERVOUS TISSUE; BLOOD BASEMENT MEMBRANE: SEPARATES BOTH

5. SUBCUTANEOUS LAYER HYPODERMIS AREOLAR AND ADIPOSE TISSUE BINDS TO UNDERLYING ORGANS FIBERS CONTIGUOUS WITH DERMIS INSULATION: CONSERVE HEAT? MAJOR BLOOD VESSELS RETE CUTANEUM

6. http://classes.midlandstech.edu/carterp/Courses/bio210/chap05/lecture1.htm

7. EPIDERMIS STRATIFIED SQUAMOUS NO BLOOD VESSELS LAYERS: STRATUM BASALE (STRATUM GERMINATIVUM/ BASAL CELL LAYER) STRATUM SPINOSUM STRATUM GRANULOSUM STRATUM LUCIDUM STRATUM CORNEUM

8. http://classes.midlandstech.edu/carterp/Courses/bio210/chap05/lecture1.htm

9. STRATUM BASALE LIVING: DIFFUSION MITOSIS NUCLEI SINGLE ROW OF CUBOIDAL MELANOCYTES

10. STRATUM SPINOSUM MANY LAYERS LARGE, CENTRAL, OVAL NUCLEI KERATIN FIBERS FORMING CELLS STARTING TO FLATTEN

11. STRATUM GRANUSLOSUM 3-5 LAYERS FLATTENED GRANULAR CELLS KERATIN SHRUNKEN NUCLEI

12. STRATUM LUCIDUM IN THICKEST SPOTS: PALMS, SOLES CLEAR CELLS: NUCLEI, ORGANELLES CAN’T BE SEEN

13. STRATUM CORNEUM DEAD KERATINIZED DESMOSOMES NONNUCLEATED SQUAMOUS

14. EPIDERMAL HOMEOSTASIS RUBBED OFF CELLS = MITOSIS INCREASES IN AREAS OF HEAVIER WEAR CALLUSSES, CORNS

15. EPIDERMAL FUNCTIONS PROTECTION: PREVENTS WATER LOSS AGAINST MECHANICAL FORCE AGAINST HARMFUL CHEMICALS PREVENTS ENTRANCE OF PATHOGENS

16. MELANOCYTES MELANOSOMES PRODUCE MELANIN FROM TYROSINE SKIN COLOR ABSORBS UV RADIATION IN STRATUM BASALE BUT CELLULAR EXTENSIONS (PROCESSES) ALLOW MELANIN TO PASS TO KERATINOCYTES KERATINOCYTES SEEM TO STIMULATE MELANOCYTES TO RELEASE MELANIN

17. SKIN COLOR GENETICS & ENVIRONMENT SAME NUMBER OF MELANOCYTES BUT DIFFER IN HOW MUCH MELANIN IS PRODUCED DARK SKIN: MORE MELANIN; SINGLE, LARGE PIGMENT GRANULES LIGHTER SKIN: SMALLER AND 2-4 GRANULES ALBINISM: NO PIGMENT SUNLIGHT, UV AND X-RAYS INCREASE PRODUCTION OF MELANIN: FADES OXYGENATED BLOOD IN SKIN: LOTS OF BLOOD= PINK CYANOSIS: LOW O2: DARK RED HEMOGLOBIN

18. DERMIS DERMAL PAPILAE- ? FINGERPRINTS BINDS EPIDERMIS DENSE IRREGULAR CONNECTIVE TISSUE 1-2 MM (.5MM-3.0MM) SMOOTH MUSCLE; SKELETAL MUSCLE NERVE CELL PROCESSES: SENSORY AND MOTOR SENSE RECEPTORS (CHAP 12)

19. ACCESSORY STRUCTURES NAILS NAIL PLATE, NAIL BED- SPECIALIZED EPITHELIAL CELLS LUNULA- MITOSIS-TINY KERATINIZED SCALES

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21. HAIR FOLLICLES GROWTH CYCLE: 2-6 YEARS, REST, FALLS OUT, REPLACED ON MOST SURFACES BUT NOT ALL AS DEFINED HAIR FOLLICLE: EPIDERMAL CELLS AT BASE, HAIR ROOT: NOURISHED BY DERMAL BLOOD VESSELS MOVE UP, KERATINIZE, DIE = HAIR SHAFT BALDNESS: GENETIC DOMINANT/RECESSIVE

22. http://classes.midlandstech.edu/carterp/Courses/bio210/chap05/lecture1.htm

23. HAIR COLOR GENES DETERMINE PIGMENT TYPE AND AMOUNT MELANOCYTES: EUMELANIN: DARK HAIR PHEOMELANIN BLONDE, RED TRICHOSIDERIN: RED NO PIGMENT: WHITE MIX OF WHITE AND PIGMENTED: GRAY: SOME INTERMEDIATE COLOR = GRAY

24. ARRECTOR PILI MUSCLE ON EACH HAIR FOLICLE: GOOSE BUMPS SMOOTH MUSCLE INVOLUNTARY

25. http://classes.midlandstech.edu/carterp/Courses/bio210/chap05/lecture1.htm

27. SEBACEOUS GLANDS SPECIALIZED GLANDULAR EPITHELIAL CELLS ASSOCIATED WITH HAIR FOLLICLES: PILOSEBACEOUS UNIT BRANCHED ACINAR GLAND HOLOCRINE: FATTY MATERIAL: SEBUM: BURSTS CELL: LIPID, WAX, CELL DEBRIES INTO HAIR FOILLICLE; SOME TO SWEAT PORES (AREAS WITHOUT HAIR) KEEPS HAIR AND SKIN SOFT, PLIABLE AND WATERPROOF SCATTERED; NOT ON PALMS, SOLES; NOT ALL WITH FOLLICLES SPECIALIZED: MEIBOMIAN GLANDS: SECRETION SLOWS EVAPORATION OF TEARS

28. SWEAT GLANDS SUDORIFEROUS GLANDS WIDESPREAD BALL IN DERMIS OR SUBCUTANEOUS SPECIALIZED GLANDULAR EPITHELIAL CELLS MOST NUMEROUS/ FOUND IN MOST AREAS: ECCRINE: RESPOND TO INCREASED BODY TEMPS ARE MEROCRINE: ODORLESS; MOSTLY H2O AND SALT, A LITTLE UREA CONTROLLED BY SYMPATHETIC NERVOUS SYSTEM APOCRINE GLANDS: ARE ACTUALLY MEROCRINE MORE VISCOUS FLUID; DEVELOP SCENT FROM SKIN BACTERIA; ACTIVATED AT PUBERTY IN ARMPITS, AREOLA, GENITALANAL AREA; HAIR FOLLICLES STIMULATED BY ADRENALINE

29. MODIFIED SWEAT.T GLANDS: CERUMINOUS GLANDS AND MAMMARY GLANDS

30. http://classes.midlandstech.edu/carterp/Courses/bio210/chap05/lecture1.htm

31. REGULATION OF BODY TEMPERATURE HOMEOSTASIS: HEAT PRODUCED= HEAT LOST HEAT PRODUCTION: CELLULAR RESPIRATION SET POINT IN: HYPOTHALAMUS: VASODILATION/VASOCONSTRICTION HEART

32. HEAT LOSS RADIATION: MAJOR PROCESS; INFRARED CONDUCTION: TO COOLER OBJECT IN CONTACT (CHAIR/AIR) CONVECTION: WARMER AIR MOVES AWAY AND COOLER AIR IS THEN HEATED EVAPORATION: ECCRINE SWEAT GLANDS RELEASE SWEAT EVAPORATES AND CARRIES HEAT AWAY

33. HEAT RETENTION VASOCONSTRICTION: STOPS RADIATION, CONDUCTION, CONVECTION, SWEAT GLANDS INACTIVE STOPS EVAPORATION CONTRACTION OF MUSCLES WHICH COULD LEAD TO SHIVERING

34. HEAT REGULATION PROBLEMS HOT, HUMID DAY: NO EVAPORATION HYPERTHERMIA IF HOTTER THAN BODY TEMP MAY GAIN HEAT FROM ENVIRONMENT PROLONGED COLD EXPOSURE/SICKNESS: HYPOTHERMIA SHIVERING MENTAL CONFUSION, LETHARGY, LOSS OF REFLEXES, LOSS OF CONSCIOUSNESS, MAJOR ORGANS SHUT DOWN, DEATH BODIES CORE CAN ONLY DROP A FEW DEGREES, EXTREMETIES CAN SURVIVE DROPS TO 20-30° F RISK: HOMELESS, AGED, YOUNG, VERY THIN

35. HEALING INFLAMMATION: BLOOD VESSELS DILATE AND INCREASE PERMEABILITY: EDEMA BECOME: RED, SWOLLEN, HOT, PAINFUL ? BENEFIT: PROVIDE MORE O 2 AND NUTRIENTS

36. HEALING CUTS SHALLOW: EPITHELIAL CELLS INCREASE MITOSIS DEEP: BLOOD VESSEL CUT: CLOTTING FIBRIN FORMED FROM ANOTHER BLOOD PROTEIN WHICH TRAPS PLATELETS DRIES: SCAB EPITHELIAL CELLS REPLICATE FIBROBLASTS MOVE IN AND SECRETE COLLANGENOUS FIBERS CONNECTIVE TISSUE MATRIX RELEASES GROWTH FACTORS INCREASE MITOSIS BLOOD VESSELS EXTEND IN PHAGOCYTES REMOVE DEAD CELLS AND DEBRIS SCAB SLOUGHS OFF SCAR COULD FORM

37. SCAR TOO WIDE GRANULATIONS FORM: NEW BLOOD VESSEL AND FIBROBLASTS SECRETE COLLAGENOUS FIBERS BLOOD VESSELS ARE RESORBED, FIBROBLASTS MOVE SCAR IS MOSTLY COLLAGENOUS FIBERS

38. BURNS 1 ST DEGREE: PARTIAL THICKNESS: ONLY EPIDERMIS; REDNESS, MILD EDEMA,MAY SHED; MILD SUNBURN HEALS QUICKLY, NO SCARRING 2 ND DEGREE: DEEP PARTIAL THICKNESS: EPIDERMIS AND SOME DERMIS;FLIUID LEAKS FROM CAPILLARIES: BLISTERS; DARK RED TO WAXY WHITE; HOT OBJECTS OR LIQUIDS, FLAMES, BURNING CLOTHES; HEALING DEPENDS ON EPIDERMAL STEM CELLS IN ACCESSORY STRUCTURES OF DERMIS ?; NO SCARRING UNLESS INFECTED

39. BURNS 3 RD DEGREE: FULL THICKNESS: DESTROYS EPIDERMIS, DERMIS AND ACCESSORY STRUCTURES; LEATHERY, RED TO WHITE OR BLACK; IMMERSION IN HOT LIQUIDS, PROLONGED EXPOSURE TO HOT OBJECTS, FLAMES OR CORROSIVE CHEMICALS; SCARRING; GRAFTING MAY BE NEEDED: WHY? AUTOGRAFT ALLOGRAFT (MUST BE REPLACED) SKIN SUBSTITUTES AMNIOTIC MEMBRANE, ARTIFICIAL MEMBRANES, CULTURED EPITHELIAL CELLS,

40. http://classes.midlandstech.edu/carterp/Courses/bio210/chap05/lecture1.htm

41. LIFE SPAN CHANGES EPIDERMIS: MITOSIS SLOWS: LARGER, IRREGULAR BUT LESS; SCALY: KERRATIN BONDS; ‘AGE SPOTS’ FROM OXIDATION OF GLANDS; DERMIS: FIBER PRODUCTION SLOWS: THINS; WITH LOSS OF ADIPOSE (SUBCUTANEOUS): WRINKLING; HEALING SLOWWS (LESS FIBROBLASTS); OIL PRODUCTION DECREASES: SKIN DRIES; ACCESSORY GLANDS: LESS MELANIN: WHITE HAIR; HAIR GROWTH SLOWS, HAIRS THIN, FOLLICLE NUMBER DECREASES, BALDNESS (MALES); LESS BLOOD TO NAILS: SLOWS GROWTH, HARDEN; LESS PAIN AND PRESSURE RECEPTORS;

42. LIFE SPAN CHANGES (CONT.) TEMPERATURE CONTROL LESSENS: LESS SWEAT GLANDS AND LESS CAPILLARIES TO GLANDS; SHIVERING ABILITY LESSENS; LESS DEEPER BLOOD VESSELS AND LESS ABILITY TO SHUNT BLOOD TO INTERIOR: FEEL COLD; PALE: LESS BLOOD VESSELS IN SKIN; BED SORES: CHANGES IN BLOOD VESSELS; GET LESS VITAMIN D AND GET OUTSIDE LESS: AFFECTS BONE MAY NEED SUPPLEMENTAL VITAMIN D;

43. THINGS TO KNOW What is the integumentary system? The parts, membrane type, functions. Layers, what is found there, functions Layers of epidermis: what is present, purpose, melanocytes, What determines skin color Accessory structures: nails, hair, oil glands, sweat glands How body temperature is regulated, heat is lost, retained, problems with regulation

44. How healing occurs in the different layers, scar formation Characteristics of different types of burns, healing, grafting Life span changes: epidermis, dermis, accessory glands, temperature control