中枢神经系统解剖(英文版)

Nervoussystem1DepartmentofAnatomyLuzhouMedicalCollegeEditedbyprofessorXiao

Nervoussystem

Introduction

Thenervoussystemiscomposedoftwoparts,thecentralnervoussystemandperipheralnervoussystem.Theformerisrepresentedbythebrainandspinalcord;whilethelatterconsistsofthespinalandcranialnerves.Theautonomicnervoussystem,oftenconsideredasaseparatefunctionalentity,isapartcentralandapartperipheral.BrainSpinalcordCranialnervesSpinalnervesNervoussystemasawholeThenervoussystempossesses(拥有)particularimportanceinallorgansandsystemsofhumanbody.Itmodulates（调整）thedifferentcells,tissuesandorgans,tocompletecertainactivitiesorresponse（反射）exteriorstimulus（外界刺激）forthebenefitoforganism（机体）asawhole.Thebrainiscommonlyregardedastheorgansolelyconcernedwiththought,memoryandconsciousness.Allinformationwehaveconcerningtheworldaboutusisconveyedcentrallytothebrainbyanelaborate（精心的详尽的）sensorysystem.Nervoussystem

Introduction

Receptorofmanykindsactastransducerswhichchangephysicalandchemicalstimuliinourenvironmentintonerveimpulsewhichthebraincanreadandgivemeaningto.Attention,consciousness,emotionalexperienceandsleepareallcentralneuralfunctions.Suchhigherfunctionsasmemory,imagination(想像力),thoughtandcreativeabilityarepoorlyunderstood（难懂的）butmustberelatedtocomplexneuronalactivity.Whilethegrossfeaturesofthehumanbrainarenotespeciallyimpressive（印象）,itsversatility（多功能性）,potentialcapabilities（濽能）,efficiency（效率）andself-programmingnature（自我谋略天性）putitinaclassbeyondany“electronicbrain”.Nervoussystem

Introduction

TheelementsofthenervoussystemThenervoussystemcomposedofnervoustissuethatconsistsofbillionsofnervecells(neurons)andsupportedbyaspecialvarietyofconnectivetissueknownasneuroglia.（神经胶质）Theneuron（神经元）Theneuronareindependentstructuralunitofthenervoussystemandarefunctionalspecializedforreception,integration（整合）,andtransmissionofcodedinformation（编码）.Nervoussystem

Introduction

RoughgranularEndoplasmicreticulumSmoothgranularEndoplasmicreticulumMicrotubuleSchwann’scellMyelinsheathLysosomesLipofuscin脂褐质dendriteEachneuronpossessesanucleatedcellbodyandtwotypesofprocesses(突起),anneuron,whichconductsimpulseawayfromthecellbody,andoneormoredendrites（树突）thatconductsimpulsestowardsthecellbody.Bothoftheseprocessesshowmarkedmorphological（形态学的）difference.Thecellbodyservesasmetabolic（代谢的）centeroftheentireunitandconsistsofalarge,pale（灰白的）nucleus（胞核）andcytoplasm（细胞浆）(perikaryon).Nervoussystem

Introduction

ThestructuresoftheneuronThenuclearenvelopeisdouble-layeredmembranewithnumerouspores（小孔）.Thechromatin（染色质）consistsmostlyoflargemoleculesofdeoxyribonucleicacid(DNA).Thenucleolus（核仁）occupiesaprominentpositioninthenucleus,whichisrichinribonucleicacid(RNA).Asinallcells,thenucleusengagesinmarkeddegreeofproteinsynthesis（蛋白质合成）.Theorganelles（细胞器）containedwithinthecytoplasm（细胞质你）arecommontoothercellsinthebody,butthereisabundantgranularendoplasmicreticulumthatconstitutestheNisslbody,aproteinsynthesisapparatus.Nervoussystem

Introduction

engagein从事于ThestructuresoftheneuronThemicrotubulesandneurofilamentsinthecytoplasmextendthroughoutthecellbodyandprocessesandconstitutethecytoskeletonoftheneuron,whichareinvolvedinthemaintenanceoftheshapeofneuronandfacilitate（易于）transferofsubstancebetweenthecellsbodyandcellprocesses.Theneuronalsocontainsabundantlysosomes（溶酶体）,andmitochondria（线粒体）forenergymetabolism.Therearelipofuscin（脂褐质）granules(prominentlyinsomelargeadultneuron)whicharebyproductsofmetablism,andtheneuromelanin（神经黑色素）granulesinthesubstantianigraandlocusceruleuswhicharethewasteproductofcatecholamine（儿茶酚胺）synthesisprobably.Nervoussystem

Introduction

ThestructuresoftheneuronTheaxonisaslenderprocess.Itmayarisefromtheconicalregionofthecellbodycalledaxonhillock,orfromthebaseofoneofthemaindendrites.Theaxongivesrisetoseveralsidebranchesorcollaterals,usuallyorientedperpendicular（垂直的）tothemainaxonprocess.Distally,theaxonbreaksupintofinebranchesthatendinswollenbuttoncalledbuttonterminaloraxonterminal.Thelattercomesintocontactwithotherneuronstoformsynapse,orwithmuscletocausemusclecontraction,orwiththeglandtocausesecretion.Theplasmicmembraneoftheaxonisknownasaxolemma（轴膜）andtheinteriorofaxoncalledaxoplasm（轴索原浆）.TheaxoplasmdiffersfromthecytoplasmofthedendritesbycompleteabsenceoftheNisslbody.Componentsoftheaxoplasmconsistofagranularendoplasmicreticulum,mitochondria,microtubulesandneurofilments.Theterminalsegmentsofaxoncomprisesnumeroussynapticvesiclesthatcontainneurotransmittersubstances.Nervoussystem

Introduction

ThestructuresoftheneuronBecausetheaxoplasmdoesnotcontainRNA,proteinssynthesiscannottakeplaceintheaxon.Allaxonalproteins,therefore,mustcomefromthecellbody,andproductsaretransportedbyaperpetual（永久的）axoplasmicmotion,someorganelles,structuralproteinandneurotransmitterscontainedwithincytoplasmarecarriedbyaxoplasmicflowwhichmovesinbothdirectionsandwithvaryingvelocity.Theanterogradetransport,movingfromthecellbodytothenerveterminals,hastwotypesofrate:oneistheslowtransport,whichisbulkflow（总体流动）ofaxoplasmcarryingmitochondria,lysosomes（溶酶体）andvesicles;theotherisarapidtransportwhichmovesthemembrane-boundvesicles,andothermaterial.Nervoussystem

Introduction

AxoplasmictransportTheretrogradetransports,movingfromthesynapticterminaltothecellbody,provideafeedbackpassage.Somepinocytotic（胞饮的）materialuptakenbyanaxonalterminalsordistaldendritesarecarriedtothecellbodyforutilizationorlysosomaldegradation.Theaxoplasmictransportcanbeusedexperimentallytodetermineneuronalconnectivity（连通性）byanaxon-tracingtechniqueandgasaclinicimplicationascentripetal（向心力）transportofneurotoxic（神经毒素）andinfectiveagents,whichmayberesponsibleforsomedisease.Nervoussystem

Introduction

AxoplasmictransportThedendritesconstituteprotoplasmic(原浆)extensionsofthecellbody.Themainorprimarydendritesarisesfromthecellbodyandthenbranchrepeatedlyinatree-likemannertoformacomplexdendritestree.Further,thedendritesarestudded（颗粒状的）withalargemembersofthorn（棘）likeprocess,dendritespinesorgemmulus（芽）,whicharestructuresspecializedforsynopticcontact.Inthismannerthedendritesgreatlyincreasethereceptivesurfacearea（接收面积）ofthewholeneuronandthusenhance（增加）thescope（机会）foritsbeinginfluencedbyotherneurons.Toalargeextend,thediversity（多样性）amongneuronsdependsonthecomplexity,configurationsandpositionofthedendrites.Nervoussystem

Introduction

AxoplasmictransportNervoussystem

Introduction

ClassificationoftheneuronneuronBipolarneuron

pseudounipolarneuronMultipolarneuronAccordingtothenumberOftheirprocessesneuronSensoryneuronMotorneuron

AssociationneuronAfferentneuronEfferentneuronIntermediateneuronfunctionallyneuronSmall

Medium

Large

From10～200umBipolarneuronpseudounipolarneuronMultipolarneurondendritenucleusaxonNisslbodyAxonhillockNervoussystem

Introduction

nervousfibersThelongerprocessesoftheneuronenvelopedbythemyelinsheathandtheneurilemmaaretermednervefibers.Themyelinatedfibersaresurrounded