組胚教研室陳同強

CirculatorySystem循環系統

Nisslbodies

Synapse

Internode0目的與要求1、掌握心臟結構2、掌握大中小動脈的結構特點和功能3、了解靜脈的結構特點4、掌握毛細血管的光鏡結構及幾種毛細血管的超微結構1Circulatorysystemisaclosedtubularsystemconsistingofcardiovascularandlymphatic

vascularsystem.

B.Thelymphaticvascularsystembeginsinblind-endedlymphaticcapillaries,whichanastomoseinlymphaticvesselsandthenemptyintothelargeveinsneartheheartbylymphaticducts.A.Thecardiovascularsystemincludestheheart,arteries,capillariesandveins.Theyareholloworgans,wallofwhichiscomposedof3andlinedwithendothelium.Introduction

tunics(tunica)膜2Ⅰ.Heart

–apump,hollowmuscularorgan1.Thewalloftheheart–3layers:rightventriclerightatriumendocardium心內膜myocardium心肌膜epicardium心外膜3(1)Endocardium–thininnerliningcomposedof2layersEndothelium:simplesquamousepithelium

:athinsheetofconnectivetissue.consistsoflooseconnectivetissuecontainingbloodvessles,nervesandtheconductingsystemoftheheart.Subendotheliallayer內皮下層Subendocardiallayer心內膜下層4(2)Myocardium

Composedofrichlysuppliedwithcapillaries.Thickerinventriclesthaninatria,andthickestintheleftventricle.

AtrialmyocardialfiberscontainspecificatrialgranulessecretingThishormoneincreasesexcretionofwaterandsodiumionsanddecreasesbloodpressure.cardiacmuscle心肌atrialnatriureticpeptide(ANP).心房納尿肽5–oftheConsistsofathinlayeroflooseconnectivetissuecoveredby(simplesquamousepithelium

).Numerousadiposecellsinthe(3)Epicardiumpericardium心包膜viscerallayer臟層subepicardiallayer.心外膜下層mesothelium間皮(4)Cardiacvalve6Sinoatrialnodeoccupiesasubepicardialpositionnearjunctionofthesuperiorvenacavaandtherightatrium.Othersarelocatedinsubendocardiallayer.

Composedofthesinoatrialnode(SAnode),atrioventricularnode(AVnode),AVbundleandthenetworkofPurkinjefibers.2.ConductingsystemoftheheartThreetypesofspecializedcardiacmusclecells:Pacemakercell(P-cell),transitionalcelland

Purkinjefiber.Differingsignificantlyfromordinaryworkingmyocardialcells.7(1).Pacemakercell(Pcell):

pale

appearanceunderbothLMandEM,thesiteofpacemaker

impulseformation,smallerthanordinarycardiacmuscularcells,morenumerousintheSAnodeandAVnode,particularlyintheircentralpart;(2).Transitionalcell:intermediatebetweensimpleP-cellsandmorecomplexordinarycardiacmuscularcells,distributedintheperipheryoftheSAnodeandtheAVnode.8(3).Purkinjefiber

/

cell–terminalbranchesofconductingsystema.Broaderandshorterthanordinarycardiacmusclefibers.b.Palestainedandrichinsarcoplasm(肌漿).Twonucleimaybefound.c.Fewmyofibrils,majorityofthemdistributedintheperipheryofthecell;abundantglycogen.d.Well-developedintercalateddiscsbetweenPurkinjefibers.e.Conductimpulsesmuchfasterthan,andtoordinarycardiacmusclefibers.9Ⅱ.Arteries–classifiedaccordingtosizeinto4groups:Large,

Medium-sized,Smallarteriesandarteriole,butnoclearly-definedlimitsexistbetweenthem.–

composedofthreeconcentriclayers:tunicaintima,tunicamediaandtunicaadventitia.Largearteries(elasticarteries)

–including主動脈、肺動脈、無名動脈、頸總動脈、鎖骨下動脈、髂總動脈等。101.tunicaintimaEndotheliumSubendotheliallayera.

Comparatively

thickerthanthatinmedium-sizedandsmallarteries.b.ComposedofendotheliumandsubendotheliallayerofLCTwhichcontainscollagenousfibersandafewlongitudinalsmoothmusclecells.c.EndothelialcellshaveWeibel-Palade(W-P)body

containingvonWillebrandtFactor(vWF)inEMtunicaintimatunicamediatunicaadventitia112.tunicamediaThickestlayer,consistingmainlyof40-70concentrically-arrangedelasticmembraneswhichareusuallyfenestratedandcomposedofelastin.Alsocontainingcollagenous,elasticfibresandsmoothmuscles.Allcomponentsareproducedbythesmoothmuscularcell.ChondroitinsulfateingroundsubstancemakingthebackgroundblueinH.E.staining.12elasticmembranessmoothmuscularcellelasticfibresLargeamountofelasticlaminaeintunicamediaareconnectedbyelasticfibers.13Thinlayeroflooseconnectivetissuecontainingsmallbloodvessels(termedvasavasorum)andnervefibres.3.Tunicaadventitia4.Function:

decreasingthebloodpressureandmakingthebloodflowconstantbydilatingperiodically.14B.Medium-sizedartery:

(Muscularartery/distributingartery).

Exceptforthelargearteries,allarterieswhichhavethenameingrossanatomy,e.g.renalartery,hepaticartery.Similartothatofthelargearteries.Distinguishinghistologicalcharacteristicsare:151.tunicaintimaconsistsofthreelayers:anendothelium,asubendotheliallayer(verythin)andanprominentinternalelasticmembrane(brightrefractilewavelikeband).2.Tunicamediaiscomposedof10-40layersofannulararrangedsmoothmusclecells(musculararteries).3.Tunicaadventitia:Asthickasthetunicamedia16Function:Regulatesthebloodflowtoorgans〔distributingarteries〕.Alayerofconnectivetissuecontainingsmallbloodvessels(vasa

vasorum)andunmylinated

.Insomearteries,theexternalelasticmembranecanbefoundbetweentunicamediaandtunicaadventitia.vasomotornerves血管運動神經171.Diameterlessthan1mm.Calledarterioleiflessthan300μm.2.Internalelasticmembranegraduallydisappears.3.Thetunicamediaismainlycomposedofseverallayersofsmoothmusclecells(musculararteries).C.Smallarteryandarteriole182-3layersofsmoothmuscleintunicamedia.Function:Responsibleforthepresenceofbloodpressure().resistancevessels阻力血管Smallartery19BasicfeaturesThesmallestbloodvesselswithanaverageluminaldiameterofabout7-9μm.Thethinnestwall(0.2-0.4μm)composedofalayerofendothelialcellsrestingonabasallamina,withinwhich

areenclosed.Distributewidelyinthebodyandformanetworkwithdifferentdensityaccordingtometabolism.Greatsurfaceareafacilitatessubstanceexchange.Ⅲ.Capillary:–exchangevessels

pericytes20Connectsthearteriolesandvenules.Mostwidelydistributed.Thinnest,simplest,longest.211.Structure:

Endothelium+basallamina+pericyte.Maydifferentiateintoendotheliumandfibroblast(surroundingCT)whentissueisinjured.Pericytecontainsrichcontractileproteinsinitsprocesses.Pericytehasbasallaminaonitsbothsurfaces.Partlysurroundstheendothelium.DifficulttodistinguishfromendotheliumunderLM.222.Classification

AccordingtotheappearanceoftheendotheliumandbasallaminainEM,capillariescanbeclassifiedas:continuouscapillary,fenestratedcapillary,sinusoidalcapillary.23Acontinuouslayerofendothelialcellsjoinedbytightjunctions.Acontinuouslayerofbasallamina.AlargenumberofpinocytoticvesiclesinthecytoplasmofendothelialcellsPresentinthemusculartissue,connectivetissue,nervoustissueandlungs.(1).Continuouscapillary:24*tightjunctions.*smallirregularprotrusionsontheinnersurfaceofendothelium.*the

pinocytoticvesiclesfortransendothelialtransportofsomewater-solublesubstances.25Thecontinuousendotheliumandbasallamina.Characterizedbypores,whosediameteris60-80nm,usuallyclosedbyadiaphragm,throughthewallofendothelialcells.(2).FenestratedcapillariesPresentintissuesinwhichrapidexchangeofsubstancesoccursbetweenthetissuesandtheblood,suchasintherenalglomerulus,submucosaofstomachandintestine,andsomeendocrineglands.26有孔毛細血管超微結構27Anwideandirregularlumen(diameterof30-40μm).Widegapsbetweenendothelialcells.Thebasallaminaisincompleteorlackatall.Endothelialcellsmayhaveporeslackingdiaphragms.Foundintheliver,spleen,bonemarrow,andincertainendocrineglands.(3).Sinusoid/sinusoidalcapillaryGreatlyfacilitatetheexchangeoffluidsandmacromoleculesacrossthewallofthesinusoidbetweenbloodandtissues28ContinuouscapillaryFenestratedcapillariesSinusoidIntercellularJunctionstightjunctionstightjunctionsnotobvious

pinocytoticvesiclesmanyfewnothaveporesnothavemanymorebasallaminacontinuouscontinuousincompleteorlackpermeabilityalittlemoremostdistributingmusculartissue,connectivetissue,nervoustissue,lungsetc.renalglomerulus,submucosaofstomachandintestine,someendocrineglandsliver,spleen,bonemarrow,certainendocrineglands293.Functionofcapillary:

Theplacewherethematerialexchangestakeplace,andthepermeabilityisregulatedbymanyfactors,suchashistamine,etc.Capillarydensityiscloselyrelatedtothelocalmetabolismrate.30

Largerdiameter,thinnerwallandfewersmoothmusclesthanaccompanyingarteries.Lumenfrequentlyappearsirregular(capacitancevessels).Alsoclassifiedinto:Large,Medium-sizedandSmallveins,Venuleandpostcapillary

venules.Internalandexternalelasticmembranesareabsent,Theboundariesbetween3layersareobscure.Ⅳ.Veins–Generalfeaturescapacitancevessel容量血管311.VenuleandpostcapillaryvenulesPostcapillaryvenulesareformedbytheconfluenceof2-4capillaries,andrangeindiameterfrom10-30umormore.Venulesareformedbytheunionofseveralpostcapillaryvenulesandhaveadiameterin50-200um.1-2layersofsmoothmusclecellsinthetunicamediaorabsent

2.Smallveins

Varyindiameterfrom0.2-1mm,Thetunicamediacontainsmainlyonetofourlayersofcircularsmoothmuscleseparatedbyelasticandcollagenousfibers.323.Medium-sizedveinsThemedium-sizedveins,withadiameterin2-9mm,includeallthenamedveinsofgrossanatomyapartfromthelargeveins.Thetunicamediaismuchthinnerthanthatofcorrespondingarteries.Thetunicaadvenitiaiswell-developedandthickerthanthetunicamedia.Somelongitudinally-orientedsmoothmusclefibersarefrequentlypresent.33Thetunicaadventitiaisrelativelythick.34

4.Largeveins.Largeveinsincludethevenoustrunkswithadiameterlargerthan1cm(頸外靜脈、無名靜脈、奇靜脈、肺靜脈、髂外靜脈、門靜脈和腔靜脈等).Thetunicamediaisverythinandcontainsonlyafewlayersofcircularsmoothmuscle.Thetunicaadventitiaisthethickestofthethreelayersandconsistsoflongitudinally-orientedsmoothmusclecells.355.Veinvalves:

Semilunar-likeprotrusionoftunicaintima,whichpreventsthebloodflowfromrunninginoppositedirection.Bepresentinmedium-sizedveinsandlargeveins(especiallynumerousinveinsoflimbs)

36Ⅴ.Lymphaticvascularsystem:Thelymphaticvascula