Skin皮膚-英文-汕頭大學(xué)醫(yī)學(xué)院課件

TheskinandSkinRegenerativeMedicineKayiName?skin

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

skinstructureandfunction

epidermis-----keratinization:proliferation/differentiationAcquaitanceAnomaliesofskin----commonskindiseases

AdvanceSkinregenerativemedicineDermisPapillarylayer+Reticularlayer第二節(jié)真皮skindermis真皮papillarylayer乳頭層reticularlayer網(wǎng)織層appendages附屬器hair毛sebaceousgland皮脂腺sweatgland汗腺THESTRUCTUREOFSKINepidermis表皮stratumcorneum角質(zhì)層stratumlucidum(透明層)stratumgranulosum顆粒層stratumspinosum棘層stratumbasale基底層nail指(趾)甲EPIDERMIS主要細(xì)胞組成keratinocyte(角質(zhì)形成細(xì)胞)non-keratinocyte(非角質(zhì)形成細(xì)胞)differentiationstratumcorneum角質(zhì)層

stratumgranulosum顆粒層stratumlucidum(透明層)

stratificationstratumbasale基底層stratumspinosum棘層PSORIASIS銀屑病redandwhitehuesofscalypatchesappearingonthetopfirstlayeroftheepidermis(skin).Langerhanscell(郞格漢斯細(xì)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.Tyrosinaseisrequiredformelanocytestoproducemelaninfromtheaminoacid

tyrosine

melanocyte(黑素細(xì)胞)Melanocytesaremelanin-producingcellslocatedinthebottomlayer(thestratumbasale)oftheskin'sepidermis,themiddlelayeroftheeye(theuvea),theinnerear,meninges,Melaninisapigmentthatisresponsibleprimarilyforthecolorofskin.Nodifferenceinmelanocytenumberbetweenspecies.Thedistributionandtyrosinaseactivity!Melanoma(黑色素瘤):4%ofalldiagnosedskincancers,melanomabeginsinthemelanocytes,cellswithintheepidermisthatgiveskinitscolor.Melanomahasbeencoined“themostlethalformofskincancer”becauseitcanrapidlyspreadtothelymphsystemandinternalorgans.Withearlydetectionandpropertreatment,thecurerateformelanomaisabout95%.Onceitsspreads,theprognosisispoor.Melanomamostoftendevelopsinapre-existingmoleorlookslikeanewmole,whichiswhyitisimportantforpeopletoknowwhattheirmoleslooklikeandbeabletodetectchangestoexistingmolesandspotnewmoles.

Acnevulgaris(orcysticacne)isacommondisease,characterizedbyareasofskinwithscalyredskin,blackheadsandwhiteheads,pinheads,pimples,nodulesandpossiblyscarring.Acneaffectsmostlyskinwiththedensestpopulationofsebaceousfollicles;theseareasincludetheface,theupperpartofthechest,andtheback.Severeacneisinflammatory,butacnecanalsomanifestinnoninflammatoryforms.2Thelesionsarecausedbychangesinpilosebaceousunits,skinstructuresconsistingofahairfollicleanditsassociatedsebaceousgland,changesthatrequireandrogenstimulation.Acneoccursmostcommonlyduringadolescence,andoftencontinuesintoadulthood.Inadolescence,acneisusuallycausedbyanincreaseintestosterone,whichpeopleofbothgendersaccrueduringpuberty.AlopeciaTotalis(全頭脫毛癥）Alopeciameanslossofhairfromtheheadorbody.baldness,Hemidesmosomes(HD)areverysmallstud-orrivet-likestructuresontheinnerbasalsurfaceofkeratinocytesintheepidermisofskin.Theyaresimilarinformtodesmosomeswhenvisualizedbyelectronmicroscopy.Whiledesmosomeslinktwocellstogether,hemidesmosomesattachonecelltotheextracellularmatrix.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,pigmentationSunscreenSPF:ratiooftheminimalerythemadose(MED)ofsunscreen-protectedskinovertheMEDofunprotectedskin.CurrentlyavailableproductsofferexcellentprotectionfromUVBand,toamorevariableextent,fromUVA;therefore,theregularuseofsunscreensshouldofferprotectionagainstsunburnaswellasphotoagingAwater-resistantproductmain