5-1 chapter 5 integumentary system. 5-2 integumentary system consists of: –skin –hair –nails...

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  • Chapter 5Integumentary System

  • Integumentary SystemConsists of:SkinHairNailsGlandsFunctionsProtectionSensationTemperature regulationVitamin D productionExcretion

  • HypodermisSkin rests on this, but not a partConsists of loose connective tissueTypes of cellsFibroblastsAdipose cellsMacrophagesAlso calledSubcutaneous tissueSuperficial fascia

  • SkinDermisStructural strengthCleavage linesTwo layersReticularPapillaryEpidermisAvascularCellsLayers or strata

  • Cleavage or Tension LinesElastin and collagen fibers oriented in some directions more than others Important in surgeryIf incision parallel to lines there is less gapping, faster healing, less scar tissue

  • Dermis and Epidermis

  • Epidermal CellsCell typesKeratinocytes: Produce keratin for strengthMelanocytes: Contribute to skin colorLangerhans cells: Part of the immune systemMerkels cells: Detect light touch and pressure Desquamate: Older cells slough offKeratinization: Cells die and produce outer layer that resists abrasion and forms permeability layer

  • Epidermal StrataStratum BasaleDeepest portion of epidermis and single layerHigh mitotic activity and cells become keratinizedStratum SpinosumLimited cell divisionStratum GranulosumIn superficial layers nucleus and other organelles degenerate and cell diesStratum LucidumThin, clear zoneStratum CorneumMost superficial and consists of cornified cells

  • Epidermal Layers and Keratinization

  • Thick and Thin SkinThick skinHas all 5 epithelial strataFound in areas subject to pressure or frictionPalms of hands, fingertips, soles of feetThin skinMore flexible than thick skinCovers rest of body

  • Skin ColorDetermined by 3 factorsPigmentsMelanin: Provides for protection against UV lightAlbinism: Deficiency or absence of pigmentCarotene: Yellow pigmentBlood circulating through the skinImparts reddish hue and increases during blushing, anger, inflammationCyanosis: Blue color caused by decrease in blood oxygen contentThickness of stratum corneum

  • Accessory Skin StructuresHairFound everywhere on human body except palms, soles, lips, nipples, parts of external genitalia, and distal segments of fingers and toesGlandsSebaceous or oil glandsSudoriferous or sweat glandsCeruminous glandsMammary glandsNails

  • Hair StructureComposed of shaft and rootShaft protrudes above skin surfaceRoot located below surface and base forms the hair bulbHas 3 concentric layersMedulla: Central axisCortex: Forms bulk of hairCuticle: Forms hair surface

  • Hair Growth, Color, and MusclesHair GrowthCyclesGrowth and restingPermanent hair lossPattern balding most commonHair ColorCaused by varying amounts and types of melaninMusclesArrector pili: Muscle contraction causes hair to stand on end

  • Oil and Sweat GlandsSebaceous glandsProduce sebumOils hair and skin surfaceSudoriferous glandsMerocrine or eccrineMost commonNumerous in palms and solesApocrineFound in axillae, genitalia, around anus

  • NailsAnatomyNail root proximallyNail body distally: Eponychium or cuticleGrowthGrow continuously unlike hair

  • BurnsClassificationsFirst-degreeSecond-degreeThird-degreeSkin GraftsSplit skinArtificial skinCadavers or pigs

  • The Rule of Nines

  • Aging Effects

    Skin more easily damagedSkin becomes drierFunctioning melanocytes decrease or increase as with age spotsSunlight ages skin more rapidly

  • Clinical DisordersBacterial infectionsAcneViral InfectionsChicken pox, German measles, cold soresDecubitus ulcers or bedsoresIschemia and necrosisCancerBasal cell carcinomaSquamous cell carcinomaMalignant melanoma