醫(yī)學英語 皮膚系統(tǒng)Skin#

TheskinandSkinRegenerativeMedicine再生醫(yī)學LujunYangBurnsandPlasticsuregeryCenterforTranslationalmedicine2ndHospitalofShantouUniversityKayiName?Agingskinskin

thelargestorganinthebodyprotectsenseregulatetemperatureProductionofVitaminDClininiansDermatology-----dermatologistPlasticandestheticsurgery------plasticsurgeonKeratinocytefibroblastOBJECTIVEMaster

skinstructureandfunction

epidermis-----keratinization角化作用:proliferation增殖/differentiation分化AcquaitanceAnomalies異?，F(xiàn)象

ofskin----commonskindiseases

AdvanceSkinregenerativemedicine皮膚再生醫(yī)學INTRODUCTIONepidermisdermishypodermisDermis真皮Papillarylayer乳頭層+Reticularlayer網狀層第二節(jié)真皮epidermishypodermisdermisskindermis真皮papillarylayer乳頭層reticularlayer網織層appendages附屬器hair毛sebaceousgland皮脂腺sweatgland汗腺THESTRUCTUREOFSKINepidermis表皮stratumcorneum角質層stratumlucidum(透明層)stratumgranulosum顆粒層stratumspinosum棘層stratumbasale基底層nail指(趾)甲EPIDERMIS主要細胞組成keratinocyte(角質形成細胞

)non-keratinocyte(非角質形成細胞)differentiationstratumcorneum角質層

stratumgranulosum顆粒層stratumlucidum(透明層)

stratificationstratumbasale基底層stratumspinosum棘層（一）EpidermalstratificationanddifferentiationPSORIASIS銀屑病redandwhitehuesofscalypatchesappearingonthetopfirstlayeroftheepidermis(skin).Langerhanscell(郞格漢斯細胞)Langerhanscellsaredendriticcells(antigen-presentingimmunecells)oftheskinandmucosa,andcontainlargegranulescalledBirbeckgranules.Theyarepresentinalllayersoftheepidermis,butaremostprominentinthestratumspinosum.Inskin

infections,thelocalLangerhanscellstakeupandprocessmicrobial

antigenstobecomefullyfunctionalantigen-presentingcells.Langerhanscellsderivefromthecellulardifferentiationofmonocyteswiththemarker"Gr-1"(alsoknownas"Ly-6G/Ly-6C").Thisdifferentiationrequiresstimulationbycolonystimulatingfactor(CSF)-1.6Theyaresimilarinmorphologyandfunctiontomacrophages.Albinoslackanenzymecalledtyrosinase絡氨酸酶.Tyrosinaseisrequiredformelanocytestoproducemelaninfromtheaminoacid

tyrosine

melanocyte(黑素細胞)Melanocytesaremelanin-producingcellslocatedinthebottomlayer(thestratumbasale)oftheskin‘sepidermis,themiddlelayeroftheeye(theuvea),theinnerear,meninges,Melaninisapigment色素

thatisresponsibleprimarilyforthecolorofskin.Nodifferenceinmelanocytenumberbetweenspecies.Thedistributionandtyrosinaseactivity!VitiligoMelanoma(黑色素瘤):4%ofalldiagnosedskincancers,melanomabeginsinthemelanocytes,cellswithintheepidermisthatgiveskinitscolor.Melanomahasbeencoined“themostlethalformofskincancer”becauseitcanrapidlyspreadtothelymphsystemandinternalorgans.Withearlydetectionandpropertreatment,thecurerateformelanomaisabout95%.Onceitsspreads,theprognosisispoor.Melanomamostoftendevelopsinapre-existingmoleorlookslikeanewmole,whichiswhyitisimportantforpeopletoknowwhattheirmoleslooklikeandbeabletodetectchangestoexistingmolesandspotnewmoles.

TheHair

SebaceousGlands

皮脂腺SweatGlands

TheNails

TheAccessaryStructuresoftheSkinAcnevulgaris尋常痤瘡普通粉刺

(orcysticacne)isacommondisease,characterizedbyareasofskinwithscaly鱗狀的

redskin,blackheads黑頭粉刺

andwhiteheads,pinheads針頭,pimples丘疹,nodules小瘤

andpossiblyscarring結疤.Acneaffectsmostlyskinwiththedenset密集

populationofsebaceousfollicles皮脂腺;theseareasincludetheface,theupperpartofthechest,andtheback.Severeacneisinflammatory炎癥性的,butacnecanalsomanifest顯現(xiàn)

innoninflammatoryforms.2Thelesions損傷

arecausedbychangesinpilosebaceous毛囊皮脂腺

units,skinstructuresconsistingofahairfollicleanditsassociatedsebaceousgland,changesthatrequireandrogen雄性激素

stimulation.Acneoccursmostcommonlyduringadolescence,andoftencontinuesintoadulthood.Inadolescence,acneisusuallycausedbyanincreaseintestosterone睪丸素,whichpeopleofbothgenders性別

accrueduringpuberty青春期.AlopeciaTotalis(全頭脫毛癥）Alopeciameanslossofhairfromtheheadorbody.baldness,Hemidesmosomes(HD)areverysmallstud-orrivet-likestructuresontheinnerbasalsurfaceofkeratinocytesintheepidermisofskin.Theyaresimilarinformtodesmosomeswhenvisualizedbyelectronmicroscopy.Whiledesmosomeslinktwocellstogether,hemidesmosomesattachonecelltotheextracellularmatrix.Desmosomes細胞橋粒

aremolecularcomplexesofcelladhesion黏著蛋白

proteinsandlinkingproteinsthatattachthecellsurfaceadhesionproteinstointracellularkeratin

角蛋白cytoskeletal細胞支架細胞

filaments細絲.Thecelladhesionproteinsofthedesmosome,desmoglein橋粒芯蛋白

anddesmocollin橋粒膠蛋白,aremembersofthecadherin鈣粘蛋白

familyofcelladhesionmolecules.Theyaretransmembraneproteinsthatbridgethespacebetweenadjacentepithelialcellsbywayofhomophilicbindingoftheirextracellulardomainstootherdesmosomalcadherinsontheadjacentcell.Bothhavefiveextracellulardomains,andhavecalcium-bindingmotifs.Age-associatedskinchangesincludethinning,skinlaxity松弛,fragility脆弱,andwrinkles皺紋.Sun-exposedareasdemonstrateadditionalagingchanges,includingdyspigmentation,prematurewrinkling,telangiectasia,andactinicelastosis.UVA400–315nmUVB315–280nmThesun

emitsultravioletradiationintheUVA,UVB,andUVCbands.TheEarth'sozonelayer

blocks97–99%ofthisUVradiationfrompenetratingthroughtheatmosphere.OftheultravioletradiationthatreachestheEarth'ssurface,98.7%isUVAPhotoaging光老化UVandmolecularandgeneticchangesUVBrayisconsideredasaprimarymutagenthatcanonlypenetratethroughtheepidermaloroutermostlayeroftheskin,resultinginDNAmutations.Theepidermallayerdoesnotcontainanybloodvesselsornerveendingsbutmelanocytesandbasalcellsareembeddedinthislayer.UponexposuretoUVBrays,melanocyteswillproducemelanin,apigmentthatgivestheskinitscolortone.However,UVBwillcausetheformationoffrecklesanddarkspots,bothofwhicharesymptomsofphotoaging.WithconstantexposuretoUVBrays,signsofphotoagingmightappearandprecancerouslesionsorskincancermaydevelop.UVAraysareabletopenetratedeeperintotheskinascomparedtoUVBrays.Hence,inadditiontotheepidermallayer,thedermallayerwillalsobedamaged.Thedermisisthesecondmajorlayeroftheskinanditcomprisescollagen,elastin,andextrafibrillarmatrixwhichprovidesstructuralsupporttotheskin.However,withconstantUVAexposure,thesizeofthedermislayerwillbereduced,therebycausingtheepidermistostartdroopingoffthebody.Duetothepresenceofbloodvesselsinthedermis,UVArayscouldleadtodilatedorbrokenbloodvesselsmostcommonlyvisibleonthenoseandcheeks.Photoaging:telangiectasia,pigmentationLaserandPhotonskintreatmentSunscreenSPF:ratiooftheminimalerythemadose(MED)ofsunscreen-protectedskinovertheMEDofunprotectedskin.CurrentlyavailableproductsofferexcellentprotectionfromUVBa