分子细胞生物学课件：Connective Tissue

ConnectiveTissueCTEPCT=cells+fibers+groundsubstanceEpCTBVMesenchymalTissueinMesodermfeaturesofconnectivetissue1.cells：fewermanykindsnonplarity2.abundantintercellularmatrix3.noBMrichinBV/nervefibersKindsandOriginationofCTCTproper:1.LooseCT2.DenseCT3.ReticularT4.Adipose(fat)TSpecialCT:5.CartilageT6.Osseous(bone)T7.BloodOriginatedfrommesenchymeMesenchymemesenchymalcelldifferenciatesintoallconnectivecellandbloodvessels,muscles,bodycavities,extraembryonicmesodermday14-16Day14Haemangioblasts

-initialcelltype:

differentiateto

(1)Angioblasts(2)Haematopoiticstemcells(1)(2)

CTcomponents:

cells+fibers+groundsubstancecomponentsofCTCTcellsintercellularmatrixfibersgroundsubstance

(indifferentphysicalproperties)fluid:bloodsolid/notcalcified:cartilagehardcalcified:bonecolloid:CTproper

cellsinconnectivetissue

fixedcellsfibroblast/adipocyte/undifferentiatedmessechymalcellwanderingcellsplasmacell/macrophage/mastcell/leukocytesconnectiveintercellularmatrixfiberscollagenfiberelasticfiberreticularfibergroundsubstance

proteoglycansglycoproteintissuefluidFibers&cellsinLooseCT

spreadpreparation/bluedyeinjectedCollagenousFiberpinkinHEsectionwhitewhenfresh

collagentypeI:dermis,bone,capsule,tendons,ligamentstypeII:cartilages(hyaline/elastic)typeIII:reticularfiber(inliver,LO,kidney,uterus...)typeIV:

BMtypeV:skin,fetal/placentaltissue...typeIforming:

collagen(incell)fibrilfiberbundles(inmatrix)peptidetypeI:(a1(I))2,a2thick/strongresistanttotensiontypeII:(a1(II))3thinfibrilsresistanttopressuretypeIII:(a1(III)3thin/argyrophilicstructuralmaintenancetypeIV:(a1(IV))3thinamorphousfiltration/supportiontypeV:(a1(V))3small/bindtotypeIassociatettotypeItypeXI:aI(XI)a2(XI)a3(XI)smallassociatedtotypeII-------------------------------------------------------------------fibrilstypeIX:aI(IX)a2(IX)a3(IX)small/vitreousbodytypeXII:a1(XII)3skin/tendonassociatedwithtypeItypeXVI:a1(XVI)3fetalskintypeVII:a1(VII)3basalepitheliaanchoringEMofcollagenfibrilsincrossandlongitudinalsections.Eachfirilshowsregularalternativedarkandlightbands

-crossstriations.TypeIcollagen(indermis):themostcommontypeinCT,tendon,ligament,capsule,skin...whitewhenfresh,pinkinHEsectiontendstoformbigbundlesTypeIIcollagenincartilagematrix--finecollagenfirils(barelyvisible)

MesentreyspreadunderpolaringMbundlesofcollagenF/thinelasticFyoungratmesentreyspreadperapation

Elasticfiber:inelastictissueslightpinkinHE,yellowwhenfreshonefibercontainsabundleofmicrofibrils(fibrillin)anddepsitionsofmuchelastinsfibrillin-resistancetoforce(upto6Xsteel)elastin-elasticity:stretcheasily(upto300x)

Elasticmembranesinlargearterywall(silverstain)ReticularfiberTypeIIIcollagencoatedbyproteoglycansinconspicuousinHEaphinitivetosilversalt(argyrophilicfiber)ReticularfiberinlymphnodesilverstainExtracellularmatrixinmouseendometriumunderEMAnetworkofproteoglycans(Groundsubstance)fillstheintercellularspaces.GroundsubstanceAcomplexmolecularmixtureofmultihesiveglycoproteins,proteoglycans,glycosaminoglycans,andtissuefluidAmorphous(LM):colourlessandtransparentGranularparticlesunderEM:aggregatedmoleclesViscouspropertyFillsthespacebetweencellsandfibersActsasbothalubricantandabarriertothemorphouselementsMolecularstructuesofProteoglycansandGlycoproteinsA:acoreofproteinboundwithmuchGAGsB:aglobularproteinboundwithlessmonosaccharidesand/oroligosacchareidesproteoglycansproteins+glycosaminoglycanshyaluronicacid(HA):thelongest,2.5uchondroitinsulfateA/Cdermatansulfate(chondroitinsulfateB)heparinsulfateglycosaminoglycans

(richin-NH2and-SO4)groundsubstancestructure

--"molecularsieve"proteinchondroitindermatenHAproteinBarrierfunctionofproteoglycansConstituteastablemicroenvironmentforlivingcellsActasabarriertothepenetrationofinvadingbacteriaandotherparticularsubstancesHAasehydrolizesHAtoreducetheviscosityofgroundsubstanceThehyaluronidaseproducingbacteria:havegreatinvasivepowerintissuesFibron(FN)/Laminin(LN)/Chondronectin(CN)Importantglycoproteinsinmatrixcellrecognitioncelladhesioncellproliferationcelldifferentiationcellmigrationtisureorganization......Associatedespeciallywithtissue/organformationinembryo

Fibroblastactive(fibroblast)/quiescent(fibrocyte)Fibroblast:largeelongatedovoidalwithbranchedprocesses,weakbasophiliccytoplasm,richinRERalargedevelopedGolgicomplex

producefibersandgroundsubstances---atypicalproteinsynthesizingcellFibrocyte:

small,thinspindle,littleacidophiliccytoplasmcanbeactivatedrepeatedly

"Physicalscars":easilyactivatedFibroblastsinconnectivetissue

-normalratdermissectionActivefibroblatsinscartissue

someofthemaremyofibroblasts

-causewoundcontractionMacrophage(LM)

1.origin:derivedfrommonocytenumberanddistribution:muchinLO,Liver,inflammatorysites....kinds:constitutemononuclearphagocytesystem2.sizeandshape:largeirregular3.abigacidophiliccytoplasm(smallN/Pratio)4.nucleus:onesmalleccentricalkidneyshapefinefilamentouschromatininconspicuousenucleolemmaandnucleolusMacrophage(EM)

--ultrastructuresrelatedtoitsfunction1.pseudopodiaandprotrusions-engulfandmigration2.developedMF/MT/IF(cytoskeleton)-movement3.Lysosomes(primary/secondary/residualbody-digestion4.phagocyticgranule(pinocyticvescicle/phagosome)

-ingest

Macrophage'sfunction1.migration:ameboidmovement,

chemotaxisattractedbychemotacticfactor2.pahgocytosis:recognition,adhesion,engulfing,digestion3.secretion:(>50bioactivemolecules)TGF-b-stimulatingcellproliferation...IL-1-stimulatingLcInterferon-antivirus,antitumourTNF-inflamationPGF-growthfactorproteinases-inflamationandtissueremodeling4.immunereaction:initiatesimmunereactionantigen-presentingPlasmacellPlasmacell(protein-synthesisizing)OriginatedfromBlymphocteMuchinmucosa,chronicinflammatorysite(esp.inpolypus)OvoidbasophilicwithapalestainedareanearnulceusRichinRERBigGolgicomplexChromatin:clockfacepatern(wheel-likenucleus)Function:secrete

immunoglobulin

MastcellMastcell-strctureLocation:nearsmallbloodvesselsLargeovoid,smallneucleus,gE-receptorsAbundantroughgranules:membranecoated,0.3-2nm,heterogeneous,scroll-like,basophilic,watersoluble,metachromatic(metachromasia:changecolorofapplieddye)vasoactivesubtancesandinflamativemediators

histamine,E-chemotactors,heparin---ingranulesproteases(chymase/tryptase),PGd2,

leukotriene-C4(SRS),TNFa,ILs---outofgranulesMastcell-allergic/inflammativefunctionactivatedbybridgecouplingof1Agto2IgE-Rleadstodegranulationandsynthesiseofmediators

smoothmuscleconstraction,bloodvesseldilationand