中枢神经系统解剖(英文版)

Nervoussystem1DepartmentofAnatomyLuzhouMedicalCollegeEditedbyprofessorXiaoNervoussystemIntroductionThenervoussystemiscomposedoftwoparts,thecentralnervoussystemandperipheralnervoussystem.Theformerisrepresentedbythebrainandspinalcord;whilethelatterconsistsofthespinalandcranialnerves.Theautonomicnervoussystem,oftenconsideredasaseparatefunctionalentity,isapartcentralandapartperipheral.BrainSpinalcordCranialnervesSpinalnervesNervoussystemasawholeThenervoussystempossesses(拥有)particularimportanceinallorgansandsystemsofhumanbody.Itmodulates（调整）thedifferentcells,tissuesandorgans,tocompletecertainactivitiesorresponse（反射）exteriorstimulus（外界刺激）forthebenefitoforganism（机体）asawhole.Thebrainiscommonlyregardedastheorgansolelyconcernedwiththought,memoryandconsciousness.Allinformationwehaveconcerningtheworldaboutusisconveyedcentrallytothebrainbyanelaborate（精心的详尽的）sensorysystem.NervoussystemIntroduction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”.NervoussystemIntroductionTheelementsofthenervoussystemThenervoussystemcomposedofnervoustissuethatconsistsofbillionsofnervecells(neurons)andsupportedbyaspecialvarietyofconnectivetissueknownasneuroglia.（神经胶质）Theneuron（神经元）Theneuronareindependentstructuralunitofthenervoussystemandarefunctionalspecializedforreception,integration（整合）,andtransmissionofcodedinformation（编码）.NervoussystemIntroductionRoughgranularEndoplasmicreticulumSmoothgranularEndoplasmicreticulumMicrotubuleSchwann’scellMyelinsheathLysosomesLipofuscin脂褐质dendriteEachneuronpossessesanucleatedcellbodyandtwotypesofprocesses(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).NervoussystemIntroductionThestructuresoftheneuronThenuclearenvelopeisdouble-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.NervoussystemIntroductionengagein从事于ThestructuresoftheneuronThemicrotubulesandneurofilamentsinthecytoplasmextendthroughoutthecellbodyandprocessesandconstitutethecytoskeletonoftheneuron,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.NervoussystemIntroductionThestructuresoftheneuronTheaxonisaslenderprocess.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.NervoussystemIntroductionThestructuresoftheneuronBecausetheaxoplasmdoesnotcontainRNA,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-boundvesicl