64脊髓

脊髓spinalcord一、脊髓的位置和外形颈膨大（C4～T1）腰骶膨大(L2～S3）长约45cm占据椎管上2/3部分与脊柱的弯曲一致重约35g椎管内上端－平枕骨大孔接延髓下端－新生儿L3成人L1下缘沟和裂前正中裂后正中沟前外侧沟后外侧沟脊神经节后根前根脊神经后正中沟前正中裂示脊髓节段每一对脊神经前、后根的根丝附着的范围即是一个脊髓节段脊髓全长可分31个节段cervical颈髓8thoracic胸髓12lumbar腰髓5sacral骶髓5coccygeal尾髓1颈膨大（C4～T1)腰骶膨大(L2～S3）颈髓第6节最粗腰髓第3节最粗两个膨大脊髓圆锥终丝马尾脊髓圆锥终丝马尾Relationshipofsegmentsofspinalcordtovertebrae脊髓节段与椎骨的对应关系RelationshipofsegmentsofspinalcordtovertebraeSpinalsegmentsVertebrallevels(spines)Uppercervicalregion(C1~C4)=C1~C4Lowercervicalandupperthoracicregion(C5~T4)—1=C4~T3Middlethoracicregion(T5~T8)—2=T3~T6Lowerthoracicregion(T9~T12)—3=T6~T9Lumbersegments=T10~T12Sacralandcoccygealsegments=L1ThemeningesofspinalcordSpinalduramater硬脊膜Spinalarachnoidmater脊髓蛛网膜Spinalpiamater软脊膜脊髓的被膜（1）硬脊膜硬膜外隙（2）脊髓蛛网膜硬膜下隙蛛网膜下隙终池（3）软脊膜终丝软脊膜蛛网膜硬脊膜椎体黄韧带齿状韧带Spinalduramater硬脊膜CharactersAbove,attachedtocircumferenceofforamenmagnumBelow,becomesthinneratlevelofS2,investsfilumterminaletoattachatbackofcoccyxEpiduralspace硬膜外隙Position:liesbetweenspinalduramaterandperiosteumofvertebralcanalContents:aquantityoflooseconnectivetissue,fat,lymphaticvesselsandvertebralvenousplexus,thespinalnervesoneachsidepassthroughtheepiduralspacewhichisapplicableforblockanesthesiaSubduralspace硬膜下隙椎管内面骨膜硬脊膜硬膜外隙蛛网膜硬膜下隙软脊膜蛛网膜下隙Spinalarachnoidmater脊髓蛛网膜CharactersAthin,delicate,tubularmembranlooselyinvestingspinalcordAbove,itiscontinuouswithcerebralarachnoidmaterSubarachnoidspace蛛网膜下隙Position:liesbetweenpiaandarachnoidmaterscontainingcerebrospinalfluidTerminalcistern终池:thelargestpartofsubarachnoidspaceextendingfromterminationofspinalcordtolevelofS2,whereitisoccupiedbynervesofcaudaequina,soitisthebestsiteforalumbarpunctureSpinalpiamater软脊膜AdelicatevascularmembranethatcloselyinveststhespinalcordDenticulateligament齿状韧带:consistof21pairstriangularligamentsextendingfromspinalcordoneachsidebetweenanteriorandposteriorrootsofspinalnervestospinalduramate;theseligamentshelptofixpositionofspinalcord.Filumterminale:anextensionofpiabeyondconusmedullaris终池终丝硬脊膜蛛网膜软脊膜Lumbarspinalpuncture(spinaltap)（二）脊髓的内部结构InternalstructuresCentralcanal中央管GraymatterAnteriorhorn(column)前角（柱）Posteriorhorn(column)后角（柱）Intermediatezone中间带Lateralhorn(column)侧角（柱）Anteriorgraycommissures灰质前连合Posteriorgraycommissures灰质后连合WhitematterAnteriorfuniculus前索lateralfuniculus外侧索Posteriorfuniculus后索Anteriorwhitecommisure白质前连合Posteriorhorn(column):Marginallayer（缘层）Substantiagelatinosa（胶状质）Nucleusproprius（后角固有核）Nucleusthoracicus（胸核）insegmentsC8~L3IntermediatezoneIntermediaolateralnucleus（中间外侧核）(lateralhornorcolumn):liesinsegmentsT1~L3,containingsympatheticpreganglionicneuronsSacralparasympatheticnucleus（骶副交感核）:liesinsegmentsS2~S4,containingparasympatheticpreganglionicneuronsIntermediomedialnucleus（中间内侧核）:forsensationofvisceraAnteriorhorn(column):containmotorneuronsThreekindsofneuronα-motorneuron:largermultipolarneuron,innervatesextrafusalfibersofskeletalm.,producingcontractionofm.γ-motorneuron:smallerneuron,innervatesintrafusalfibersregulatingmusculartonusRenshaw’scell:negativefeedbackmechanismTwogroupsofnucleiMedialnucleargroup:presentinmostsegmentsofspinalcord,innervatingaxialmusclesLateralnucleargroup:presentonlyincervicalandlumbosacralenlargements,innervatinglimbmusclesRexed’slamina板层posteriorhornisformedbylaminaⅠtoⅥ；IntermediatezonecorrespondingtolaminaⅦ；AnteriorhorniscomposedlaminaeⅧandⅨ；laminaⅩisthegraymattersurroundingthecentralcanal.ImportantSubdivisionofSpinalCordGrayMatter分区板层核团后角Ⅰ边缘带Ⅱ胶状质Ⅲ,Ⅳ，后角固有核后角颈、网状核，后角基底部中间带Ⅶ胸核(C8~L3)Ⅶ中间外侧核(T1~L3)Ⅶ副交感核(S2~S4)Ⅶ中间内侧核前角Ⅸ运动核脊髓的细胞构筑分层C6L5白质(whitematter)(1)上行纤维束薄束和楔束脊髓小脑后束脊髓小脑前束脊髓小脑吻侧束脊髓丘脑束脊髓橄榄束脊髓顶盖束脊髓前庭束脊髓皮质束脊髓脑桥束内脏感觉束WhitematterWhitemattercontainsthreekindsoffibers:ascending,descending,andfasciculuspropriusAscendingtractsFasciculusgracilis（薄束）Fasciculuscuneatus（楔束）Posteriorspinocerebellartract（脊髓小脑后束）Anteriorspinocerebellartract（脊髓小脑前束）Spinothalamictract（脊髓丘脑束）皮质脊髓束皮质脊髓侧束皮质脊髓前束薄束和楔束脊髓丘脑束SLTC浅感觉传导通路白质(whitematter)(1)上行纤维束薄束和楔束脊髓小脑后束脊髓小脑前束脊髓小脑吻侧束脊髓丘脑束脊髓橄榄束脊髓顶盖束脊髓前庭束脊髓皮质束脊髓脑桥束内脏感觉束AscendingtractsTractSiteoforiginFuniculusTerminationFunctionFasciculusgracilisSpinalgangliabelowsegmentT5PosteriorGracilenucleusConveyproprioceptiveandfinetouchsensationoftrunkandlimbsFasciculuscuneatusSpinalgangliaabovesegmentT4CuneatenucleusPosteriorspinocerebellarHomolateralnucleusthoracicusLateralCerebellumUnconsciousproprioceptionfromlowerlimbandlowerportionoftrunkAnteriorspinocerebellarContralateralLaminaeⅤ~ⅦSpinothalamicLaminaeⅠ,Ⅳ~ⅦLateralandanteriorDorsalthalamusPain,temperatureandsimpletouchsensationoftrunkandlimbs（2）下行纤维束皮质脊髓束皮质脊髓前束皮质脊髓侧束红核脊髓束前庭脊髓束顶盖脊髓束网状脊髓束内侧纵束皮质脊髓束起始1）皮质脊髓前束2）皮质脊髓侧束皮质脊髓束脊髓spinalcord皮质脊髓侧束皮质脊髓前束皮质脊髓束皮质脊髓侧束皮质脊髓前束上、下运动神经元损伤的临床表现临床表现上运动神经元损伤出现部位对侧肌张力增高瘫痪硬(痉挛性)瘫浅反射减弱或消失深反射亢进病理反射出现肌萎缩早期不明显硬软分上下，左右看交叉下运动神经元损伤同侧降低软(弛缓性)瘫消失消失不出现明显DescendingtractsLateralcorticospinaltract（皮质脊髓侧束）Anteriorcorticospinaltract（皮质脊髓前束）Rubrospinaltract（红核脊髓束）Vestibulospinaltract（前庭脊髓束）Reticulospinaltract（网状脊髓束）Mediallongitudinalfasciculus（内侧纵束）Tectospinaltract（顶盖脊髓束）Fasciculusproprius（固有束）DescendingtractsTractSiteoforigi