解剖學(xué)-英文-皮膚-skin復(fù)習(xí)課程

解剖學(xué)-英文-皮膚-SkinTHESKINSkinpigment—deepestepidermallayerisresponsibleforproductionofpigment,whichgivescolortotheskinThebrownpigmentmelaninisproducedbyspecializedcellsinthislayer(melanocytes)Dermal-epidermaljunction—specializedareabetweentwoskinlayersBlisterscancausedifthisjunctionisdamagedordestroyedTHESKIN(cont.)DermisDeeperandthickerofthetwoprimaryskinlayersandcomposedlargelyofconnectivetissue

Upperpapillarylayerofdermischaracterizedbyparallelrowsoftinybumpscalleddermalpapillae

RidgesandgroovesindermisformpatternuniquetoeachindividualBasisoffingerprintingImprovesgripfortooluseandwalkingTHESKIN(cont.)DermisDeeperreticularlayer

ofdermis:filledwithnetworkoftough,interlacing,collagenousandstretchableelasticfibers

Numberofelasticfibersdecreaseswithageandcontributestowrinkleformation

Dermisalsocontainsnerveendings,musclefibers,hairfollicles,sweatandsebaceousglands,andmanybloodvesselsTHESKIN(cont.)AccessorystructuresoftheskinHairSofthairoffetusandnewborniscalledlanugoHairgrowthrequiresepidermaltubelikestructurecalledhairfollicleHairgrowthbeginsfromhairpapillaHairrootlieshiddeninfollicleandvisiblepartofhaircalledshaftArrectorpili—specializedsmoothmusclethatproduces“goosebumps”andcauseshairtostandupstraightTHESKIN(cont.)Accessorystructuresoftheskin(cont.)ReceptorsSpecializednerveendings—makeitpossibleforskintoactasasenseorganTactile(Meissner’s)corpuscle/Merkelcell—capableofdetectinglighttouchClosetotheskinsurfacePacinicorpuscle—capableofdetectingpressureLocateddeepinthedermisFreenerveendings–painKrauseendbulbs(bulboidcorpuscles)–low-frequencyvibrationTHESKIN(cont.)Accessorystructuresoftheskin(cont.)NailsProducedbyepidermalcellsoverterminalends

offingersandtoesVisiblepartiscallednailbodyRootliesinagrooveandishiddenbycuticleCrescent-shapedareanearestrootiscalledlunulaNailbedmaychangecolorwithchangeinbloodflowTHESKIN(cont.)Accessorystructuresoftheskin(cont.)SkinglandsSweatorsudoriferousSebaceous

SweatorsudoriferousglandsEccrinesweatglandsMostnumerous,important,andwidespread

ofthesweatglandsProduceperspirationorsweat,whichflowsoutthroughporesonskinsurfaceFunctionthroughlifeandassistinbodyheatregulationTHESKIN(cont.)

ApocrinesweatglandsFoundprimarilyinaxillaandaroundgenitaliaSecreteathickersecretionquitedifferentfromeccrineperspirationBreakdownofsecretionbyskinbacteriaproducesodor

SebaceousglandsSecreteoilorsebumforhairandskinLevelofsecretionincreasesduringadolescenceAmountofsecretionisregulatedbysexhormonesSebuminsebaceousglandductsmaydarken

toformblackheadTHESKIN(cont.)SkincancerTypesSquamouscellcarcinomaBasalcellcarcinomaMalignantmelanomaKaposisarcomaCausesGeneticpredispositionSun'sultraviolet(UV)radiationdamagesskincellDNA,causingmistakesduringmitosisTHESKIN(cont.)Skincancer(cont.)Basalcellcarcinoma(mostcommontypeofskincancer)Originatesincellsatbaseofepidermis—oftenonupperfaceLesionsbeginassmallraisedareasthaterodeincenter,bleed,andcrustoverLesslikelytometastasizethanotherskincancertypesSquamouscellcarcinomaCommontypeofskincancerSlowgrowingLesionsbeginaspainless,hard,raisednodulesWillmetastasizeTHESKIN(cont.)Skincancer(cont.)MalignantmelanomaMostseriousformofskincancerMaydevelopfrombenign,pigmentedmoles

orexcessUVradiationIncidenceintheUnitedStatesisincreasingABCDruleofself-examination

(Table5-1)KaposisarcomaRareformFrequentlyassociatedwithAIDSorimmunedeficiencyTHESKIN(cont.)FunctionsoftheskinProtection—firstlineofdefenseagainst:InfectionbymicrobesUltravioletraysfromsunHarmfulchemicalsCutsandtears

TemperatureregulationSkincanreleasealmost3000caloriesofbodyheatperdayMechanismsoftemperatureregulationRegulationofsweatsecretionRegulationofflowofbloodclosetothebodysurfaceTHESKIN(cont.)Functionsoftheskin(cont.)SenseorganactivitySkinfunctionsasanenormoussenseorganReceptorsserveasreceiversforthebody,keeping

itinformedofchangesinitsenvironmentTHESKIN(cont.)BurnsTreatmentandrecoveryorsurvivaldependontotalareainvolvedandseverityordepthoftheburn

Bodysurfaceareaisestimatedusingthe“rule

ofnines”inadultsBodyisdividedinto11areasof9%eachAdditional1%locatedaroundgenitalsTHESKIN(cont.)Burns(cont.)Classificationofburns

First-degree(partial-thickness)burns—onlythesurfacelayersofepidermisinvolved

Second-degree(partial-thickness)burns—involvethedeepepidermallayersandalwayscauseinjurytotheupperlayersofthedermisTHESKIN(cont.)Burns(cont.)

Third-degree(full-thickness)burns—characterized

bycompletedestruct