组织学与胚胎学-内分泌系统--双语教学07Nerve-Tissue

NERVOUSTISSUE,神经组织,组织学与胚胎学教研室,主讲陈同强,1、掌握神经组织的基本结构，神经细胞的结构特点。2、掌握突触的超微结构特点与分类。3、掌握神经纤维的结构与分类。4、熟悉神经胶质细胞、神经末梢的分类和功能。,大纲要求,GeneralCharacteristics,Madeupof2typesofcells:(nervecell)-structuralandfunctionalunit;-supporting,protectingandnourishingneurons.,neuron,neuroglialcell,神经元,神经胶质细胞,.Neurons,Variousshapeandsizeincellbody:Maybespherical,fusiform,pyramidal,stellate,orirregularinshape.5-6umindiameter,thelargecanreachmorethan150um.Morethanoneprocesses,theshorteronlyseveralum,thelongestmorethan1m.,神经元,Cellbodyandprocesses(and),树突,轴突,dendrites,axons,1.Cellbody(metabolic,trophicandintegralcenter):Nucleus,andplasmalemma,(1).Nucleuslarge,spherical,andpale-staining;aprominent,核周质/细胞质,(2).(perinuclearcytoplasm)containing:,Nisslbodies,Perikaryon,Neurofibrils,Perikaryon,神经原纤维,尼氏体,nucleolus.,核仁,Roughendoplasmicreticulum,Indicatingactiveproteinsynthesis.,Basophilicparticles,粗面内质网,(RoughER/RER)+freeribosomes,核糖体,(a).Nisslbodies,尼氏体,thinthreadsinperikaryonandprocessesvisualizedwithsilverstaininginLM.consistingofandinbundles.serveingascytoskeleton,involvedintransportationofsubstances.,(b).Neurofibrils,neurofilaments,神经原纤维,神经丝,microtubules,微管,(c).OtherorganellessuchasGolgicomplex,mitochondrion,Lysosome,etc.,Lipofuscinisincreasedinnumberwithage.,(3).plasmalemma,2.Processesand,(1).Dendrites,Oftenbranched;Oneormore/neuron,andusuallyshortandthick;Numerousfineprojections()onsurfaces;ContainingNisslbodiesandneurofibril;,树突,轴突,dendrites,axons,dendriticspines,树突棘,Receivinginformationandconductingittoparentcellbody.,Oneaxoneachneuron;Longandthinwithuniformdiameter;doesnotbranchprofusely;afewcollateralsperpendiculartotheaxon.,轴突,(2).Axons,Function:1.Conductimpulsesawayfromcellbody.,(conicalregion);DevoidofNisslbodies;(buttons)containvesicleswithneurotransmittersinthem;,轴丘,Axonhillock,轴突终末,Axonterminals,轴突运输,2.Axonaltransport,神经递质,neurotransmitters,3.Classification,(1).AccordingtonumberofprocessesPseudounipolarfoundinspinalganglia;Bipolar:presentincochlearandvestibularganglia,retina,olfactory,etc;Multipolor:majorityofneurons.,假单极,Pseudounipolar：,(2).AccordingtofunctionSensoryorafferent;Motororefferent;Interneurons:toformcomplexfunctionalcircuits,toaccountfor99%ofneuronsinthebody.,(3).AccordingtoneurotransmitterreleasedCholinergic:acetylcholine(Ach);Noradrenergic:norepinephrine(NE)Aminergic:dopamine(DA),hydroxytryptamine;Aminoacidnergic:glycine,glutamicacid,etcPeptidergic:polypeptidessuchassubstanceP,vasopressin,etc.,胆碱能,Cholinergic:,Noradrenergic:,去甲肾上腺素能,胺能,Aminergic:,(4).AccordingtolengthofaxonGolgitypeIneuronGolgitypeIIneuron,1.Definition:Junctionbetweentwoneuronsorbetweenaneuronandaneffectorcellspecializedfortransmissionofimpulses.,突触,.Synapse,轴体突触,Axosomaticsynapse,轴棘突触,Axospinoussynapse,轴树突触,Axodendriticsynapse,2.Classification,(1).Electricalsynapse:permitdirectflowofelectricalcurrentbetweentwoneurons(gapjunction).,(2).Chemicalsynapse:useachemicalmediator(neurotransmitter)totransmitimpulsesinonedirection;,3.Structureofchemicalsynapses,(axonterminals),突触前成分,Presynapticelement,突触间隙,Synapticcleft,突触后成分,Postsynapticelement,突触小体,Synapticknob,Synapticvesicles(40-60nmindiameter,havingcontentofneurotransmitters,synapsinattachedtoitsmembrane),Mitochondrion(Mit),SmoothER(SER),Microtubule(Mt),Microfilament(Mf);,Presynapticmembranethickenedwithgrid,denseprojections.,突触前成分,(1).Presynapticelement,突触小泡,Synapticvesicles,突触素,synapsin,(2).SynapticcleftExtracellularspacebetweenpre-andpostsynapticmembranes(15-30nm).,(3).Postsynapticelement(theregiononthesurfaceofthereceivingneuronatthecontactpoint)Usuallydendrite(spine)orcellbody;Postsynapticmembranethickened;,Specificreceptorstotheneurotransmitter.,突触间隙,(2).Synapticcleft,4.Functiontransmittingimpulsesinonedirection,Calciumionentering,Synapsinphosphorylated,Vesiclesmovingtoandfusingwithpresynapticmembraneanddischargingneurotransmitters,Neurotransmittersdiffusingacrossthecleftandcombiningwiththerecepter,Permeabilityofthepostsynapticmembraneincreasingandmembranepotentialchanging,Generalfeatures,Supportingcellswithprocesses,non-excitableandnotconductimpulses;Morethanneuronsby10-50times;,OnlynucleiseeninH,神经胶质细胞,.neuroglialcell,NeuroglialcellinCNS(Astrocyte,Oligodendrocyte,Microglia,Ependymalcell),Mostnumerous,bigeststar-shaped;withoval,palestainingnucleusandmanyprocesses;,Containglialfilaments(glialfibrillaracidicprotein);Twoformsofastrocytes:fibrousandprotoplasmic;,Support,星形胶质细胞,(1).Astrocytes,胶质丝,glialfilaments,胶质原纤维酸性蛋白,(glialfibrillaracidicprotein);,神经营养因子,neurotrophicfactor(NTF),Smallerwitharound,dark-stainingnucleus;FormingaroundaxonsintheCNS.,smallestwithairregular,darklystainednucleus;Phagocytic;Derivedfrommonocytes.,少突胶质细胞,(2).Oligodendrocytes,髓鞘,myelinsheath,小胶质细胞,(3).Microglia,columnarorcuboidalepithelioidcells;liningventriclesofbrainandcentralcanalofspinalcord.,室管膜细胞,(4).Ependymalcells,2.Neurogliacellinperipheralnerveoussystem(PNS),FormingaroundaxonsinPNS;Secretingneurotrophicfactors(NTF),Guidingnerveregeneration.,(2).Satellitecells(capsularcells)Alayerofflattenedorcuboidalcells;Formingcapsulearoundneuronsin,施万细胞,(1).Schwanncells,髓鞘,myelinsheath,神经节,spinalganglia.,1.inPNS,(1).BasicstructureAxon+myelinsheath+;,NodeofRanvierPortionsdevoidofmyelinsheath;Eachsegmentbetween2consecutivenodes-oneSchwanncell.,Obliquesection,神经纤维,.NerveFibers,有髓神经纤维,Myelinatednervefibers,神经膜,neurolemma,Internode,结间体,andnerve,(2).Myelinsheath,LM:spongelike(HNoneurolemma,noincisuresofmyelin;,DifferenceofmyelinatednervefiberinPNSandinCNS1.Themyelin-formingcellsinperipheralnervoussystemaretheSchwanncells,butinthecentralnervoussystemareoligodendrocytes.2.InPNS,oneSchwanncellformsoneinternodalsegment,butinCNSoneoligodendrocyteformsseveralinternodalsegments.3.InPNS,eachmyelinatedfiberisdelimitedbyabasallamina,andsuchfibersareseparatedfromeachotherbyconnectivetissueoftheendoneurium.However,intheCNS,thereisnobasallaminaorendoneuriumsurroundingmyelinatednervefibers.4.Mesaxonsarepresentinperipheralmyelinatednervefibers,butnotinthemyelinatednervefibersoftheCNS.,Myelinsheathisformedbyprocessesofoligodendrocyteswhichcanformseveralinternode.,3.Unmyelinatednervefibers,(1)PNSThinaxons(singleorgroup)indentedintoSchwanncells;NomyelinsheathandnodesofRanvier.,(2)CNSFreeaxonsamongothermyelinatednervefibersandglialprocesses,:Myelinsheathservingasaninsulator,thenerveimpulsesjumpfromnodetonodeacrossinternodeandconductionspeedareenhanced;,Thickeraxonthickermyelinsheathandlongerinternodegreaterconductionvelocity.,(1)Myelinatednervefibers:,4.Functionalroleofnervefiber,跳跃式传导,Saltatoryconduction,(2)UnmyelinatednervefibersImpulseconductionoccursalongtheentireaxolemma(continuousconduction)lowervelocity,axolemma:Axonplasmalemma(轴膜)P62,5.Nervesbranching,cord-likestructureswhichextendoutwardsfromthebrainascranialnerves,andfromthespinalcordasspinalnerves,toreachalmosteverypartofthebody.Becomposedofnervefibersandconnectivetissue.,(1).NervefibersNervefibersMixed,bothmyelinatedandunmyelinated,sensoryandmotor.,Epineurium:FibrousCTenclosingentirenerveandalsofillingthespacebetweenbundlesofnervefibers.;Perineurium:Sheetofflattenedepithelium-likecellssurroundingeachnervebundles;Endoneurium:ThinlayerofLCTenvelopingeachnervefiber.,Ep,Pe,(2).Connectivetissue,Ep,神经扫描电镜图,1.Classification(1)Sensorynerveending(receptors)(2)Motornerveending(effectors),FreenerveendingsTactilecorpusclesLamellarcorpusclesMusclespindles,Somatic(motorendplate)Visceral,神经末梢,.Nerveendings,(1).FreenerveendingsBranchesofnakednervefibers;,Respondingtocold,heat,lighttouch,andpain.,2.Sensorynerveending,Abundantinepidermis,cornea,hairfollicles;,(2)Tactilecorpuscles,Foundindermalpapillae;OvalbodieswithCTcapsule,flattenedcellsandnerveterminal(s).Touchreceptors;,2.Sensorynerveending,(3)Lamellarcorpuscles,Distributedinsubcutaneoustissue,mesentery,lig