nervetissuenervetissue1CNS:consistingofthebrainandthespinalcord;PNS:consistingofnerves,ganglia(collectionofnervecellbodies)andspecializednerveendings.nervoussystemCNS:consistingofthebraina2Compositionofnervetissuenervetissueneurons(nervecells)supportingcellsIntheCNS:neurogliacell(gliacell)

InthePNS:SchwanncellsatellitecellCompositionofnervetissuener3FunctionofnervetissueNeuron:

toreceivestimuliandconductelectricalimpulses.Supportingcell:physicalsupport(protection)forneuronalprocesses;electricalinsulationfornervecellbodyandprocesses;metabolicexchangepathwaysbetweenvascularsystemandneuron.FunctionofnervetissueNeuron4neuron

Neuronisthefunctionalunitofthenervesystem.Itcanreceivestimuliandconductelectricalimpulses.

Structureofneuron

Neuronismadeupofcellbody(somaorperikaryon),dendriteandaxon.

1.

Soma：whereribosomes,mitichondria,andothersubcelluarpartsdothemetabolicworkofcells

Cellmembrane:

Therearesomeion-channelsandreceptorsinit.

Cytoplasm:

Nisslbodies,neurofibrils,ribosomes,mitochondria,etc.

Nucleus:

central,largeandround,lightlystained,withanobviousnucleolus.neuronNeuronisthefunc5neuronneuron6Nisslbodyinthesoma：Basophilicgranules.EachNisslbodyismadeupofastackofRERandfunctionsinproducingproteins.

Nisslbodyinthesoma：Basophi72.Dendrite：numeroustaperingbranchesformthedendritictrees,whichincreasethereceptorsurfaceareaofaneuron.ThereareNisslbodiesinthedendrites.

Function:receivingstimuliandconductingthemtothecellbody.2.Dendrite：numeroustapering8neuronneuron93.Axon:thinandlong,similarindiameter.fewbranches.withoutNisslbodies.Functionastransmittingstimulitootherneuronsoreffectorcells.

Hillock:continuouswiththeaxon,theareaofcellbodywhereisfreeoflargecytoplasmicorganells:RERandsoon.

Axonaltransportsystem：Amodeofintercellularcommunicationbetweencellbodyandtheterminalofaxon.①Anterogradetransport：fromcellbodytotheterminalofaxon（materialssynthesizedinthesoma)②Retrogradetransport：(metabolicproductsandetc.)3.Axon:thinandlong,simi10neuralstructureneuralstructure11AxonHillockAxonHillock12AxonaltransportsystemAxonaltransportsystem13

Theclassificationofneurons1.Basedonthenumberofitsprocesses①multipolarneuron：oneaxonandtwoormoredendrites

②bipolarneurons：oneaxonandonedendrite.(limitedtotheretinaandetc.)③unipolar(pseudo-unipolar)neuron：oneprocess,whichdividesclosetothecellbodyintotwolongprocesses.Theclassificationof14threetypesofneuronsthreetypesofneurons152.Basedonthefunctionoftheneuron①sensoryneuron：conveyimpulsesfromreceptors(unipolar)toCNS-------afferentneuron.②motorneuron：conveyimpulsesfromtheCNSor

(multipolar)gangliatoeffectorcellsandcontroltheactivityofmuscleandthesecretionoftheglands------efferentneuron.③interneuron:formacommunicatingandintegrating

(multipolar)

networkbetweensensoryandmotorneurons--------intercalatedneuron.2.Basedonthefunctionofthe16synapse

synapseissomespecialcelljunctionbetweenneuronsorbetweenneuronanditseffectorcell(musclefiberorglandularcell).synapseelectricalsynapsechemicalsynapsegapjunction:two-directiontransmissionindependentofneurotransmittersconsistsofpresynapticelement,synapticcleftandpostsynapticelement;one-directiontransmissionmediatedbyneurotransmitters;synapsesynapseissomespe17chemicalsynapse1.presynapticelement:bulb-likeenlargementsoftheaxonterminalswhichiscalledterminalbuttonorsynapticbag.

presynapticmembrane：presynaptic

cellmembranewith

voltagesensitivecalciumchannels.

synapticvesicles：membraneboundvesicleswhichcontainneurotransmitters.2.synapticcleft：thespacebetweenthepresynapticandpostsynapticmembranes.3.postsynapticelement：postsynaptic

cellmembranewithchemicalsensitiveionchannelsandreceptorsoftheneurotransmitters.chemicalsynapse18synapticbagsynapticbag19synapsesynapse20thetransmissionofthenerveimpulseNerveimpulsearrivesatpresynapticcellmembraneinfluxofthecalciumionsthroughthepresynapticmembraneSynapticvesiclespourtheneurotransmittersintothesynapticcleftNeurotransmittersreachandbindontocorrespondingreceptorsThepostsynapticmembranebecomesdepolarized.thetransmissionofthenerve21神經組織組織學和胚胎學課件22synapsesynapse23synapsesynapse24severalmorphologicalkindsofsynapsesaxodendritic:

occurringbetweenaxonsanddendrites;axosomatic:

occurringbetweenaxonandsoma;axoaxonic:

occurringbetweenaxonandaxon;dendrodentritic:

occurringbetweendendritesanddendrites.severalmorphologicalkindsof25kindsofsynapseskindsofsynapses26supportingcellssupportingcellsInthePNS:SchwanncellsatellitecellIntheCNS:neurogliacell:astrocyte(gliacell)oligodendrocytemicrogliaependymalcellnonconductivecells.function:insulatetheneuronsfromeachother,protecttheneurons

supportingcellssupportingcel27supportingcellsinthePNS

1.Schwanncell2.satellitecellsupportingcellsinthePNS281Schwanncellandmyelinsheath

profile:flatsacinshape

nucleus:flattened,stainsdarkly.function:surroundingtheaxonandconstitutingtheneurilemmaandmyelinsheath.

myelinsheath-formingcellinthePNS.1Schwanncellandm29formationofmyelinsheath

myelinsheath:

composedofmultiplelayersofSchwanncellmembranewrappedconcentricallyaroundtheaxon.EachSchwanncellinitiallysurroundssomepartofanaxon;Itwrapsashortsegmentofaxon,formingmultipleSchwanncelllayers,andcytoplasmissqueezedoutfrombetweenthemembraneoftheconcentriclayers;Theinnerleafletsoftheplasmamembranethenfuse.formationofmyelinsheath30formationofmyelinatedaxonformationofmyelinatedaxon31神經組織組織學和胚胎學課件32myelinatedaxonmyelinatedaxon33myelinsheathmyelinsheath34myelinatedaxon（SEM）myelinatedaxon（SEM）35longitudinalandcrosssectionsofmyelinsheathlongitudinalandcrosssection36神經組織組織學和胚胎學課件37myelinatedaxon:

surroundedbymyelinsheath

unmyelinatedaxon:

withoutmyelinsheath

inthePNSmyelinatedaxon:surroundedby38

(

1)myelinatedaxoninthePNSanditsmyelinsheath

ThemyelinsheathissegmentedbecauseitisformedbynumerousSchwanncellsarrayedsequentiallyalongtheaxon.These"breaks"inmyelinationallowforsaltatoryconduction.neurilemma(thesheathofSchwann):ItispartofSchwanncellwhichisexternalto,contiguouswith,themyelinsheath.myelinsheath:composedofmultiplelayersofSchwanncellmembranewrappedconcentricallyaroundtheaxon.Ranviernode:ThejunctionwheretwoadjacentScheanncellsmeetisdevoidofmyelin.ThissiteiscalledRernode(internodalsegment):

themyelinbetweentwosequentialRanviernodes.ItiscomposedofpartofaxonanditsmyelinsheathwhichisformedbyoneSchwanncell.(1)myelinatedaxoninthe39神經組織組織學和胚胎學課件40

(2)UnmyelinatedaxoninthePNS

TheSchwanncellsareelongated,andaxonsfitintothegroovesinthesurfaceofthecell.AsingleaxonoragroupofaxonsmaybeenclosedinthesurfaceofoneSchwanncell.(2)Unmyelinatedaxon41

2.satellitecell

alayerofcuboidalorlowcolumnarcellsthatsurroundtheneuronalcellbodyoftheganglia.

Function:

providingelectricalinsulationandphysicalprotectionoftheneuronalbody.2.satel42satellitecellsatellitecell43satellitecellsatellitecell44supportingcellsintheCNS1.neuron2.oligodendrocyte3.bloodvessel4.Axon5.astrocyte6.ependymalcell7.microgliasupportingcellsintheCNS1.451.astrocyte(fibrousandprotoplasmic)profile:largest,star-shapedglialcellsoftheCNSthathavenumerousprocesses.Manyoftheseprocessesextendtobloodvessels.Theexpandedendingsoftheastrocyteprocessesareknownasend-feet.

blood-brain-barrier:Itisformedbytightjunctionsbetweenendothelialcells,theend-feetfunctiontoinduceandmaintaintheblood-brainbarrier.

supportingcellsintheCNS1.astrocyte(fibrous46endfeetofastrocytesandBBBBBB:torestrictthematerialpermeationbetweenbloodandbrain.endfeetofastrocytesandBBB47astrocyteastrocyte48astrocyteastrocyte49（1）fibrousastrocyte：morecommoninwhitematter.Fewerprocesseswhicharerelativestraight.（1）fibrousastrocyte：morecomm50（2）protoplasmicastrocyte：moreprevalentingraymatterTheyhavenumerous,short,branchingprocesses. （2）protoplasmicastrocyte：more51

2.oligodendrocyte

Profile:smallerthanastrocyte,processesareshorterandlessthanthoseoftheastrocyte.Nucleus:smallerandstaineddarkly.Function:involvedintheformationofthemyelinsheathintheCNS.2.oligod52oligodendrocyte

andthemyelinsheathintheCNSoligodendrocyte

andthemyel53(1)myelinatedaxonintheCNS

2.oligodendrocyte4.Axon(1)myelinatedaxonintheCNS54(1)myelinatedaxonintheCNSIntheCNS,myelinsheathisformedbyoligodendrocytes.eachprocessoftheoligodendrocytescansurroundsomepartofoneaxon:Processesofoneneuroncansurroundtheaxonsofseveralneurons.(1)myelinatedaxonintheCNSI55

(2)TheunmyelinatedaxonintheCNS

Theaxonisthinner.Usuallythereisnogliasurroundingit.(2)Theunmyelinateda56

3.microgliaprofile:thesmallestgliacell.roundorthinandlonginshape.withfewerandshorterprocesses.nucleus:triangleinshapeorlookslikeapole.function:similartothatofmacrophage.

3.microgli57

microglia

microglia584.ependymalcell：column-shapedcellsthatlinetheventriclesofthebrainandcentralcanalofthespinalcord.itisanimportantpartofthebarrierbetweenthebrainandcerebrospinalfluid.4.ependymalcell：column-shape59supportingcellsintheCNSsupportingcellsintheCNS60myelinatedaxonmyelinatedaxon61axonsinthePNSaxonsinthePNS62

nervefiberandnervenervefiber:Itiscomposedoftheaxonwithorwithoutthemyelinsheath.

Basedon

thepresenceofmyelinsheath,nervefibersaredividedintotwocategories:

myelinatednervefiberandunmyelinatednervefiber.nervefiberandnervenervef63

nerve

nerve:abundleofnervefibersheldtogetherbytheconnectivetissue(C.T.).

epineurium：CTsurroundinganerve.

perineurium：CTsurroundingeachnervefiberfascicle.

endoneurium：CTsurroundingeachindividualnervefiber.

64

peripheralnerve

epineuriumendoneuriumperineuriumperipheral655.nerveendingsensorynerveendingtheterminalpartoftheperipheralarborizationofthesensoryneuron.Itcanformkindsofsensoryreceptorsinthetissueororgan.1.freenerveending2.tactilecorpuscle

3.lamellarcorpuscle

4.musclespindle5.nerveendingsensorynervee66

1.Freenerveending

terminalbranchesofthemyelinatedsensorynervefiber.Itisdevoidofmyelinsheath.Distribution:betweenthecellsofepidermis,cornealepitheliumorintheC.T.ofdermisandhairfollicles,etc.Function:

receptorofpain.

672.tactilecorpuscle(Meissner’scorpuscle)ellipse,freenerveendingswithacapsuleofC.T.Distribution:lieinthedermalpapillae.Function:servingastouchreceptors.2.tactilecorpuscle(M68

3.lamellarcorpuscle(Paciniancorpuscle)Distribution:mainlylyingindeeperdermisandhypodermis,internalorgans,etc.Function:deeppressurereceptorformechanicandvibratorypressure.3.lamellar69LamellarcorpuscleLamellarcorpuscle70LamellarcorpuscleLamellarcorpuscle714.musclespindleDistribution:liesintheskeletalmuscle.Function:serveasaspecializedstretchreceptorwithintheskeletalmuscle4.mus72motornerveending

motornerveending:

terminalbranchesofmotorneurondistributinginmuscletissueandglands.oneneuroncancontrolmanymusclefibers,whileonemusclefiberiscontrolledbyonlyoneneuron.

motorunit：aneuronalongwithitsspecificmusclefibersthatitinnervates.

motorendplate:

thejunctionbetweenmotornerveendingandskeletalmusclefibers.motornerve73motorendplatemotorendplate74motorendplatemotorendplate75神經組織組織學和胚胎學課件76Keypoint1.Thecompositionofnervetissue:neuronandsupportingcells()2.basicstructureoftheneuron(soma,dendriteandaxon)andtheNisslbody3.Classificationoftheneuron4.StructureoftheChemicalsynapse5.Myelinsheathandmyelinsheath-formingcellsinthePNSandCNS;Myelinatedaxonandunmyelinatedaxon6.Nerve;thecompositionofsensorynerveendingsandtheirfunction;motorunit;motorendplate.Keypoint1.Thecompositionof77神經組織組織學和胚胎學課件78nervetissuenervetissue79CNS:consistingofthebrainandthespinalcord;PNS:consistingofnerves,ganglia(collectionofnervecellbodies)andspecializednerveendings.nervoussystemCNS:consistingofthebraina80Compositionofnervetissuenervetissueneurons(nervecells)supportingcellsIntheCNS:neurogliacell(gliacell)

InthePNS:SchwanncellsatellitecellCompositionofnervetissuener81FunctionofnervetissueNeuron:

toreceivestimuliandconductelectricalimpulses.Supportingcell:physicalsupport(protection)forneuronalprocesses;electricalinsulationfornervecellbodyandprocesses;metabolicexchangepathwaysbetweenvascularsystemandneuron.FunctionofnervetissueNeuron82neuron

Neuronisthefunctionalunitofthenervesystem.Itcanreceivestimuliandconductelectricalimpulses.

Structureofneuron

Neuronismadeupofcellbody(somaorperikaryon),dendriteandaxon.

1.

Soma：whereribosomes,mitichondria,andothersubcelluarpartsdothemetabolicworkofcells

Cellmembrane:

Therearesomeion-channelsandreceptorsinit.

Cytoplasm:

Nisslbodies,neurofibrils,ribosomes,mitochondria,etc.

Nucleus:

central,largeandround,lightlystained,withanobviousnucleolus.neuronNeuronisthefunc83neuronneuron84Nisslbodyinthesoma：Basophilicgranules.EachNisslbodyismadeupofastackofRERandfunctionsinproducingproteins.

Nisslbodyinthesoma：Basophi852.Dendrite：numeroustaperingbranchesformthedendritictrees,whichincreasethereceptorsurfaceareaofaneuron.ThereareNisslbodiesinthedendrites.

Function:receivingstimuliandconductingthemtothecellbody.2.Dendrite：numeroustapering86neuronneuron873.Axon:thinandlong,similarindiameter.fewbranches.withoutNisslbodies.Functionastransmittingstimulitootherneuronsoreffectorcells.

Hillock:continuouswiththeaxon,theareaofcellbodywhereisfreeoflargecytoplasmicorganells:RERandsoon.

Axonaltransportsystem：Amodeofintercellularcommunicationbetweencellbodyandtheterminalofaxon.①Anterogradetransport：fromcellbodytotheterminalofaxon（materialssynthesizedinthesoma)②Retrogradetransport：(metabolicproductsandetc.)3.Axon:thinandlong,simi88neuralstructureneuralstructure89AxonHillockAxonHillock90AxonaltransportsystemAxonaltransportsystem91

Theclassificationofneurons1.Basedonthenumberofitsprocesses①multipolarneuron：oneaxonandtwoormoredendrites

②bipolarneurons：oneaxonandonedendrite.(limitedtotheretinaandetc.)③unipolar(pseudo-unipolar)neuron：oneprocess,whichdividesclosetothecellbodyintotwolongprocesses.Theclassificationof92threetypesofneuronsthreetypesofneurons932.Basedonthefunctionoftheneuron①sensoryneuron：conveyimpulsesfromreceptors(unipolar)toCNS-------afferentneuron.②motorneuron：conveyimpulsesfromtheCNSor

(multipolar)gangliatoeffectorcellsandcontroltheactivityofmuscleandthesecretionoftheglands------efferentneuron.③interneuron:formacommunicatingandintegrating

(multipolar)

networkbetweensensoryandmotorneurons--------intercalatedneuron.2.Basedonthefunctionofthe94synapse

synapseissomespecialcelljunctionbetweenneuronsorbetweenneuronanditseffectorcell(musclefiberorglandularcell).synapseelectricalsynapsechemicalsynapsegapjunction:two-directiontransmissionindependentofneurotransmittersconsistsofpresynapticelement,synapticcleftandpostsynapticelement;one-directiontransmissionmediatedbyneurotransmitters;synapsesynapseissomespe95chemicalsynapse1.presynapticelement:bulb-likeenlargementsoftheaxonterminalswhichiscalledterminalbuttonorsynapticbag.

presynapticmembrane：presynaptic

cellmembranewith

voltagesensitivecalciumchannels.

synapticvesicles：membraneboundvesicleswhichcontainneurotransmitters.2.synapticcleft：thespacebetweenthepresynapticandpostsynapticmembranes.3.postsynapticelement：postsynaptic

cellmembranewithchemicalsensitiveionchannelsandreceptorsoftheneurotransmitters.chemicalsynapse96synapticbagsynapticbag97synapsesynapse98thetransmissionofthenerveimpulseNerveimpulsearrivesatpresynapticcellmembraneinfluxofthecalciumionsthroughthepresynapticmembraneSynapticvesiclespourtheneurotransmittersintothesynapticcleftNeurotransmittersreachandbindontocorrespondingreceptorsThepostsynapticmembranebecomesdepolarized.thetransmissionofthenerve99神經組織組織學和胚胎學課件100synapsesynapse101synapsesynapse102severalmorphologicalkindsofsynapsesaxodendritic:

occurringbetweenaxonsanddendrites;axosomatic:

occurringbetweenaxonandsoma;axoaxonic:

occurringbetweenaxonandaxon;dendrodentritic:

occurringbetweendendritesanddendrites.severalmorphologicalkindsof103kindsofsynapseskindsofsynapses104supportingcellssupportingcellsInthePNS:SchwanncellsatellitecellIntheCNS:neurogliacell:astrocyte(gliacell)oligodendrocytemicrogliaependymalcellnonconductivecells.function:insulatetheneuronsfromeachother,protecttheneurons

supportingcellssupportingcel105supportingcellsinthePNS

1.Schwanncell2.satellitecellsupportingcellsinthePNS1061Schwanncellandmyelinsheath

profile:flatsacinshape

nucleus:flattened,stainsdarkly.function:surroundingtheaxonandconstitutingtheneurilemmaandmyelinsheath.

myelinsheath-formingcellinthePNS.1Schwanncellandm107formationofmyelinsheath

myelinsheath:

composedofmultiplelayersofSchwanncellmembranewrappedconcentricallyaroundtheaxon.EachSchwanncellinitiallysurroundssomepartofanaxon;Itwrapsashortsegmentofaxon,formingmultipleSchwanncelllayers,andcytoplasmissqueezedoutfrombetweenthemembraneoftheconcentriclayers;Theinnerleafletsoftheplasmamembranethenfuse.formationofmyelinsheath108formationofmyelinatedaxonformationofmyelinatedaxon109神經組織組織學和胚胎學課件110myelinatedaxonmyelinatedaxon111myelinsheathmyelinsheath112myelinatedaxon（SEM）myelinatedaxon（SEM）113longitudinalandcrosssectionsofmyelinsheathlongitudinalandcrosssection114神經組織組織學和胚胎學課件115myelinatedaxon:

surroundedbymyelinsheath

unmyelinatedaxon:

withoutmyelinsheath

inthePNSmyelinatedaxon:surroundedby116

(

1)myelinatedaxoninthePNSanditsmyelinsheath

ThemyelinsheathissegmentedbecauseitisformedbynumerousSchwanncellsarrayedsequentiallyalongtheaxon.These"breaks"inmyelinationallowforsaltatoryconduction.neurilemma(thesheathofSchwann):ItispartofSchwanncellwhichisexternalto,contiguouswith,themyelinsheath.myelinsheath:composedofmultiplelayersofSchwanncellmembranewrappedconcentricallyaroundtheaxon.Ranviernode:ThejunctionwheretwoadjacentScheanncellsmeetisdevoidofmyelin.ThissiteiscalledRernode(internodalsegment):

themyelinbetweentwosequentialRanviernodes.ItiscomposedofpartofaxonanditsmyelinsheathwhichisformedbyoneSchwanncell.(1)myelinatedaxoninthe117神經組織組織學和胚胎學課件118

(2)UnmyelinatedaxoninthePNS

TheSchwanncellsareelongated,andaxonsfitintothegroovesinthesurfaceofthecell.AsingleaxonoragroupofaxonsmaybeenclosedinthesurfaceofoneSchwanncell.(2)Unmyelinatedaxon119

2.satellitecell

alayerofcuboidalorlowcolumnarcellsthatsurroundtheneuronalcellbodyoftheganglia.

Function:

providingelectricalinsulationandphysicalprotectionoftheneuronalbody.2.satel120satellitecellsatellitecell121satellitecellsatellitecell122supportingcellsintheCNS1.neuron2.oligodendrocyte3.bloodvessel4.Axon5.astrocyte6.ependymalcell7.microgliasupportingcellsintheCNS1.1231.astrocyte(fibrousandprotoplasmic)profile:largest,star-shapedglialcellsoftheCNSthathavenumerousprocesses.Manyoftheseprocessesextendtobloodvessels.Theexpandedendingsoftheastrocyteprocessesareknownasend-feet.

blood-brain-barrier:Itisformedbytightjunctionsbetweenendothelialcells,theend-feetfunctiontoinduceandmaintaintheblood-brainbarrier.

supportingcellsintheCNS1.astrocyte(fibrous124endfeetofastrocytesandBBBBBB:torestrictthematerialpermeationbetweenbloodandbrain.endfeetofastrocytesandBBB125astrocyteastrocyte126astrocyteastrocyte127（1）fibrousastrocyte：morecommoninwhitematter.Fewerprocesseswhicharerelativestraight.（1）fibrousastrocyte：morecomm128（2）protoplasmicastrocyte：moreprevalentingraymatterTheyhavenumerous,short,branchingprocesses. （2）protoplasmicastrocyte：more129

2.oligodendrocyte

Profile:smallerthanastrocyte,processesareshorterandlessthanthoseoftheastrocyte.Nucleus:smallerandstaineddarkly.Function:involvedintheformationofthe