CHAPTER 6. INTEGUMENTARY SYSTEM SKIN Largest organ by weight ACCESSORY STRUCTURES

INTEGUMENTARY SYSTEMCHAPTER 6

INTEGUMENTARY SYSTEMSKIN

Largest organ by weightACCESSORY STRUCTURES

SKINFUNCTIONS:

MAINTAIN HOMEOSTASISPROTECTIVE COVERINGPREVENT WATER LOSSREGULATE BODY TEMPERATURESENSE RECEPTORSSYNTHESIZES CHEMICALSIMMUNE SYSTEM CELLSEXCRETES SOME WASTE

CUTANEOUS MEMBRANEEPIDERMIS

STRATIFIED SQUAMOUS EPITHELIUMDERMIS

THICKERCONNECTIVE TISSUE: DENSE IRREGULAR;

AREOLAR; SMOOTH MUSCLE; NERVOUS TISSUE; BLOOD

BASEMENT MEMBRANE: SEPARATES BOTH

SUBCUTANEOUS LAYERHYPODERMISAREOLAR AND ADIPOSE TISSUEBINDS TO UNDERLYING ORGANSFIBERS CONTIGUOUS WITH DERMISINSULATION:

CONSERVE HEAT?MAJOR BLOOD VESSELS

RETE CUTANEUM

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EPIDERMISSTRATIFIED SQUAMOUS

NO BLOOD VESSELSLAYERS:

STRATUM BASALE (STRATUM GERMINATIVUM/ BASAL CELL LAYER)

STRATUM SPINOSUMSTRATUM GRANULOSUMSTRATUM LUCIDUMSTRATUM CORNEUM

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STRATUM BASALELIVING: DIFFUSIONMITOSISNUCLEISINGLE ROW OF CUBOIDALMELANOCYTES

STRATUM SPINOSUMMANY LAYERSLARGE, CENTRAL, OVAL NUCLEIKERATIN FIBERS FORMINGCELLS STARTING TO FLATTEN

STRATUM GRANUSLOSUM3-5 LAYERSFLATTENED GRANULAR CELLSKERATINSHRUNKEN NUCLEI

STRATUM LUCIDUMIN THICKEST SPOTS: PALMS, SOLESCLEAR CELLS: NUCLEI, ORGANELLES

CAN’T BE SEEN

STRATUM CORNEUMDEADKERATINIZEDDESMOSOMESNONNUCLEATEDSQUAMOUS

EPIDERMAL HOMEOSTASISRUBBED OFF CELLS = MITOSISINCREASES IN AREAS OF HEAVIER WEARCALLUSSES, CORNS

EPIDERMAL FUNCTIONSPROTECTION:

PREVENTS WATER LOSSAGAINST MECHANICAL FORCEAGAINST HARMFUL CHEMICALSPREVENTS ENTRANCE OF PATHOGENS

MELANOCYTESMELANOSOMES PRODUCE MELANIN

FROM TYROSINESKIN COLORABSORBS UV RADIATIONIN STRATUM BASALE BUT CELLULAR

EXTENSIONS (PROCESSES) ALLOW MELANIN TO PASS TO KERATINOCYTES

KERATINOCYTES SEEM TO STIMULATE MELANOCYTES TO RELEASE MELANIN

SKIN COLORGENETICS & ENVIRONMENTSAME NUMBER OF MELANOCYTES BUT DIFFER IN

HOW MUCH MELANIN IS PRODUCEDDARK SKIN: MORE MELANIN; SINGLE, LARGE

PIGMENT GRANULESLIGHTER SKIN: SMALLER AND 2-4 GRANULESALBINISM: NO PIGMENTSUNLIGHT, UV AND X-RAYS INCREASE PRODUCTION

OF MELANIN: FADESOXYGENATED BLOOD IN SKIN: LOTS OF BLOOD=

PINKCYANOSIS: LOW O2: DARK RED HEMOGLOBIN

DERMISDERMAL PAPILAE- ?FINGERPRINTSBINDS EPIDERMISDENSE IRREGULAR CONNECTIVE TISSUE1-2 MM (.5MM-3.0MM)SMOOTH MUSCLE; SKELETAL MUSCLENERVE CELL PROCESSES: SENSORY AND

MOTORSENSE RECEPTORS (CHAP 12)

ACCESSORY STRUCTURESNAILS

NAIL PLATE, NAIL BED- SPECIALIZED EPITHELIAL CELLS

LUNULA- MITOSIS-TINY KERATINIZED SCALES

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HAIR FOLLICLESGROWTH CYCLE: 2-6 YEARS, REST, FALLS

OUT, REPLACEDON MOST SURFACES BUT NOT ALL AS

DEFINEDHAIR FOLLICLE: EPIDERMAL CELLS AT

BASE, HAIR ROOT: NOURISHED BY DERMAL BLOOD VESSELS

MOVE UP, KERATINIZE, DIE = HAIR SHAFTBALDNESS: GENETIC

DOMINANT/RECESSIVE

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HAIR COLORGENES DETERMINE PIGMENT TYPE AND

AMOUNTMELANOCYTES:

EUMELANIN: DARK HAIRPHEOMELANIN BLONDE, REDTRICHOSIDERIN: REDNO PIGMENT: WHITEMIX OF WHITE AND PIGMENTED: GRAY:

SOME INTERMEDIATE COLOR = GRAY

ARRECTOR PILI MUSCLEON EACH HAIR FOLICLE: GOOSE BUMPSSMOOTH MUSCLEINVOLUNTARY

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SEBACEOUS GLANDSSPECIALIZED GLANDULAR EPITHELIAL CELLS

ASSOCIATED WITH HAIR FOLLICLES: PILOSEBACEOUS UNIT

BRANCHED ACINAR GLANDHOLOCRINE: FATTY MATERIAL: SEBUM: BURSTS CELL:

LIPID, WAX, CELL DEBRIESINTO HAIR FOILLICLE; SOME TO SWEAT PORES (AREAS

WITHOUT HAIR)KEEPS HAIR AND SKIN SOFT, PLIABLE AND WATERPROOFSCATTERED; NOT ON PALMS, SOLES; NOT ALL WITH

FOLLICLESSPECIALIZED: MEIBOMIAN GLANDS: SECRETION SLOWS

EVAPORATION OF TEARS

SWEAT GLANDSSUDORIFEROUS GLANDSWIDESPREADBALL IN DERMIS OR SUBCUTANEOUSSPECIALIZED GLANDULAR EPITHELIAL CELLSMOST NUMEROUS/ FOUND IN MOST AREAS: ECCRINE:

RESPOND TO INCREASED BODY TEMPSARE MEROCRINE: ODORLESS; MOSTLY H2O AND SALT, A

LITTLE UREACONTROLLED BY SYMPATHETIC NERVOUS SYSTEMAPOCRINE GLANDS: ARE ACTUALLY MEROCRINEMORE VISCOUS FLUID; DEVELOP SCENT FROM SKIN

BACTERIA; ACTIVATED AT PUBERTY IN ARMPITS, AREOLA, GENITALANAL AREA; HAIR FOLLICLESSTIMULATED BY ADRENALINE

MODIFIED SWEAT.T GLANDS: CERUMINOUS GLANDS AND MAMMARY GLANDS

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REGULATION OF BODY TEMPERATUREHOMEOSTASIS: HEAT PRODUCED= HEAT

LOSTHEAT PRODUCTION:

CELLULAR RESPIRATIONSET POINT IN:

HYPOTHALAMUS:VASODILATION/VASOCONSTRICTIONHEART

HEAT LOSSRADIATION:

MAJOR PROCESS; INFRARED

CONDUCTION: TO COOLER OBJECT IN CONTACT (CHAIR/AIR)

CONVECTION: WARMER AIR MOVES AWAY AND COOLER AIR IS

THEN HEATEDEVAPORATION:

ECCRINE SWEAT GLANDS RELEASE SWEATEVAPORATES AND CARRIES HEAT AWAY

HEAT RETENTIONVASOCONSTRICTION:

STOPS RADIATION, CONDUCTION, CONVECTION,

SWEAT GLANDS INACTIVESTOPS EVAPORATION

CONTRACTION OF MUSCLES WHICH COULD LEAD TO SHIVERING

HEAT REGULATION PROBLEMSHOT, HUMID DAY:

NO EVAPORATIONHYPERTHERMIAIF HOTTER THAN BODY TEMP MAY GAIN HEAT FROM

ENVIRONMENTPROLONGED COLD EXPOSURE/SICKNESS:

HYPOTHERMIASHIVERINGMENTAL 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

HEALINGINFLAMMATION:

BLOOD VESSELS DILATE AND INCREASE PERMEABILITY: EDEMA

BECOME: RED, SWOLLEN, HOT, PAINFUL ?BENEFIT:

PROVIDE MORE O2 AND NUTRIENTS

HEALING CUTSSHALLOW:

EPITHELIAL CELLS INCREASE MITOSISDEEP:

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

SCARTOO WIDEGRANULATIONS FORM:

NEW BLOOD VESSEL AND FIBROBLASTSSECRETE COLLAGENOUS FIBERSBLOOD VESSELS ARE RESORBED,

FIBROBLASTS MOVESCAR IS MOSTLY COLLAGENOUS FIBERS

BURNS1ST DEGREE:

PARTIAL THICKNESS: ONLY EPIDERMIS; REDNESS, MILD EDEMA,MAY SHED;

MILD SUNBURNHEALS QUICKLY, NO SCARRING

2ND 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

BURNS3RD 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,

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LIFE SPAN CHANGESEPIDERMIS:

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;

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;

THINGS TO KNOWWhat is the integumentary system? The

parts, membrane type, functions .Layers, what is found there, functionsLayers of epidermis: what is present,

purpose, melanocytes,What determines skin colorAccessory structures: nails, hair, oil glands,

sweat glandsHow body temperature is regulated, heat is

lost, retained, problems with regulation

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