神經(jīng)系統(tǒng)教學(xué)課件：整合-Spinal Cord

Nervoussystem

神經(jīng)系統(tǒng)器官系統(tǒng)為基礎(chǔ)的醫(yī)學(xué)整合課程

適應(yīng)21世紀(jì)社會、經(jīng)濟(jì)、科技和文化發(fā)展的需求，符合醫(yī)學(xué)模式的轉(zhuǎn)變：

環(huán)境-社會-心理-工程-生物-醫(yī)學(xué)；

21世紀(jì)的醫(yī)學(xué)將從“疾病醫(yī)學(xué)”向“健康醫(yī)學(xué)”發(fā)展；器官系統(tǒng)為基礎(chǔ)的醫(yī)學(xué)整合式教學(xué)，將有利于人類對生命現(xiàn)象、健康的認(rèn)識，以及對疾病發(fā)生、發(fā)展、演變過程的預(yù)防和治療。Why器官系統(tǒng)為基礎(chǔ)的醫(yī)學(xué)整合課程

以人體十大器官系統(tǒng)為切入點(diǎn)，將與該系統(tǒng)有關(guān)的基礎(chǔ)知識（解剖、組胚、生理、病理和藥理等）加以有機(jī)整合，在此基礎(chǔ)上結(jié)合該系統(tǒng)常見疾病作臨床導(dǎo)論介紹，為今后臨床醫(yī)學(xué)課程的學(xué)習(xí)打好基礎(chǔ)。器官系統(tǒng)相關(guān)的基礎(chǔ)醫(yī)學(xué)各學(xué)科間的整合，基礎(chǔ)醫(yī)學(xué)與臨床醫(yī)學(xué)之間的整合，也包括人體各器官系統(tǒng)相互之間的聯(lián)系與整合。

神經(jīng)系統(tǒng)NervousSystem學(xué)習(xí)相關(guān)課程內(nèi)容—神經(jīng)解剖學(xué)、神經(jīng)生理學(xué)、病理解剖學(xué)、藥理學(xué)、神經(jīng)病學(xué)等，注重各學(xué)科間的交叉、融合、滲透在神經(jīng)系統(tǒng)形態(tài)結(jié)構(gòu)的基礎(chǔ)上，介紹正常功能、病理改變、發(fā)病機(jī)制、神經(jīng)系統(tǒng)藥物的作用及機(jī)制、神經(jīng)系統(tǒng)常見疾病的臨床概述及神經(jīng)系統(tǒng)檢查方法等把神經(jīng)系統(tǒng)相關(guān)的基礎(chǔ)醫(yī)學(xué)各學(xué)科間的內(nèi)容有機(jī)整合，同時也注重本器官系統(tǒng)相關(guān)的基礎(chǔ)醫(yī)學(xué)與臨床醫(yī)學(xué)之間的整合Thenervoussystemdynamicallyintegratedcontentsrelatedtothenervoussystemfromallthebasicmedicalsubjectsonthebasisoforganandsystem.Italsoemphasizesthecombinationofbasicandclinicalmedicalscienceandhasbecomeamulti-disciplinarycoursecoveringbasic,clinicalandlifescience.Basedonhumanorgansandsystems,thenervoussystemintroducesthestructureandmorphology,physiologicalfunctions,pathologicalalterations,pharmacologicalreactions,imageologyandclinicaldiagnosticsofthenervoussystem.Itisanimportantpartofthemedicalscience.《神經(jīng)系統(tǒng)》是以器官系統(tǒng)為基礎(chǔ)，力求把神經(jīng)系統(tǒng)相關(guān)的基礎(chǔ)醫(yī)學(xué)各學(xué)科間的內(nèi)容有機(jī)整合，注重本器官系統(tǒng)的基礎(chǔ)醫(yī)學(xué)與臨床醫(yī)學(xué)之間的整合，是一門基礎(chǔ)醫(yī)學(xué)、臨床醫(yī)學(xué)乃至生命科學(xué)多學(xué)科交叉、融合的課程。本課程以人體的器官系統(tǒng)為基礎(chǔ)，闡述人體神經(jīng)系統(tǒng)的形態(tài)結(jié)構(gòu)、生理功能、病理變化、藥理作用、神經(jīng)系統(tǒng)影像以及神經(jīng)系統(tǒng)診斷等，是醫(yī)學(xué)科學(xué)中的重要內(nèi)容。Nervoussystem

神經(jīng)系統(tǒng)Centralnervoussystem(CNS)Peripheralnervoussystem(PNS)

Thehumannervoussystemisacontrolsystemthatregulatesandcoordinatesallfunctionsoftheorgan.Besides,itisalsothesiteofallmentalactivity,includingconsciousness,memory,andthinking.MainDivisions:GeneralDescriptionCENTRALNERVOUSSYSTEM

brainspinalcordPERIPHERALNERVOUSSYSTEM

cranialnervesspinalnerves

visceralnervoussystem

(autonomic

orvegetativenervoussystem)DivisionoftheNervousSystem

brainTelencephalon端腦Diencephalon間腦Cerebellum小腦Brainstem腦干CentralNervousSystem中樞神經(jīng)系統(tǒng)

脊髓SpinalCord

Thespinalcordprovidesacrucialinformationconduit,connectingthebrainwithmostofthebody.SpinalReflexes.Position

Thespinalcordoccupiestheuppertwo-thirdsoftheadultspinalcanalwithinthevertebralcolumn脊柱椎管.

Thecordisnormally42~45cmlonginadultsandiscontinuouswiththemedullaatitsupperend.Theconusmedullaris

脊髓圓錐istheconicaldistal(inferior)endofthespinalcord.Inadults,theconusendsattheLIorL2levelofthevertebralcolumnandatbirthatlevelofL3.foramenmagnum

EXTERNALANATOMYOFTHESPINALCORD

Alongcylindricalstructureandslightlyflattenedanteroposteriorly,

Filumterminale終絲extendsfromthetipoftheconus圓錐andattachestothedistalduralsac.Thefilumterminaleconsistsofpiaandglialfibersandoftencontainsavein.

Caudaequina馬尾Thelumbosacralrootsdescendforvaryingdistanceswithintheterminalcisternabeforereachingtheircorrespondingintervertebralforamina.Externalfeatures

Thespinalcordwidenslaterallyinthecervicalenlargement頸膨大andthelumbosacralenlargement腰骶膨大.

Theenlargementsofthecordcontainincreasednumbersoflowermotorneuronsandprovidetheoriginsofthenervesoftheupperandlowerextremities.Thenervesofthebrachialplexusoriginateatthecervicalenlargement;thenervesofthelum-bosacralplexusarisefromthelumbarenlargement.EnlargementsC4totheT1segmentsL2totheS3segments

Anteriormedianfissure前正中裂

itsflooristheanteriorwhitecommissure.

Posterior(ordorsal)mediansulcus后正中溝

Thedorsalnerveroots(sensory)areattachedtothespinalcordalongtheposterolateralsulcus

后外側(cè)溝,

Theventralnerveroots(motor)exitintheanterolateralsulcus

前外側(cè)溝.

whichconstitutesthefirstcell-stationofthesensorynervesLongitudinaldivisionsSpinalcordsegments脊髓節(jié)段

Thespinalcordisdividedinto31segments.8cervical(C)segments,12thoracic(T)segments,5lumbar(L)segments,5sacral(S)segments,andacoccygeal(Co)segments-----thatcorrespondtoattachmentsofgroupsofnerveroots.Therelationbetweenspinalcordsegmentsandvertebralbodies

脊髓節(jié)段與椎骨的對應(yīng)關(guān)系

Untilthethirdmonthoffetallife,thespinalcordisaslongasthevertebralcanal.Afterthatpoint,thevertebralcolumnelongatesfasterthanthespinalcord.Becausethespinalcordisshorterthanthevertebralcolumn,eachspinalcordsegmentatlowerlevelsislocatedabovethesimilarlynumberedvertebralbody.SpinalsegmentsVertebrallevelsC1~C4=C1~C4C5~T4—1=C4~T3T5~T8—2=T3~T6T9~T12—3=T6~T9Lumbersegments=T10~T12Sacralandcoccygealsegments=L1患者.劍突及以下感覺障礙、消失。MRI檢查顯示硬脊膜腫瘤壓迫脊髓所致。問題：

1.硬脊膜腫瘤壓迫脊髓節(jié)段的平面？2.手術(shù)切除硬脊膜腫瘤進(jìn)入椎管的部位及椎骨的平面？Lumbarpuncture腰椎穿刺*examinationofcerebrospinalfluid*spinalanaesthesiaCentralcanal

中央管

INTERNALDIVISIONSOFTHESPINALCORD脊髓內(nèi)部結(jié)構(gòu)

Thecentralcanalislinedwithependymaicellsandfilledwithcerebrospinalfluid.Itopensupwardintotheinferiorportionofthefourthventricle.AnteriorfuniculuslateralfuniculusPosteriorfuniculus

AnteriorwhitecommisureLateralhorn(column)Whitematter白質(zhì)

AnteriorgraycommissuresPosteriorgraycommissures

(T1--L3)Graymatter灰質(zhì)anH-shapedinternalmass

Anteriorhorn(column)Posteriorhorn(column)Intermediatezone

Medialnucleargroup內(nèi)側(cè)核群:innervatingaxialmuscles

Lateralnucleargroup外側(cè)核群:presentonlyincervicalandlumbosacralenlargements,innervatinglimbmusclesGrayMattar灰質(zhì)containsalphaandgammamotorneurons(lowermotorneurons).Thelarge-diameteralphamotorneuronaxonstotheextrafusalstriatedmusclefibers,producingcontraction;thesmallergammamotorneuronaxons,whichsupplytheintrafusalmuscle,regulatingmusculartonus.

Renshaw’scell:negativefeedbackmechanism.Anteriorcolumn(horn)

前柱(角)LesionofanteriorhornofthespinalcordGrayMattarIntermediolateralcolumn(horn)中間外側(cè)柱(角):aprominentlateraltriangularprojectioninthethoracicandupperlumbarregionsbutnotinthemidsacralregion.Itcontainspreganglioniccellsfortheautonomicnervoussystem.Theseneuronsgiverisetopreganglionicsympathetic

（T1～L3）交感神經(jīng)節(jié)前神經(jīng)元orparasympatheti（S2～4）副交感神經(jīng)節(jié)前神經(jīng)元axonsthatleavethespinalcordwithintheventralroots.Intermediomedialnucleus中間內(nèi)側(cè)核:forsensationofvisceraIntermediatezone中間帶

Marginallayer邊緣層Substantiagelatinosa膠狀質(zhì)Nucleusproprius固有核Nucleusthoracicus胸核inC8~L3segmentsGrayMattarPosteriorcolumn(horn)

后柱(角)reticularformationLaminaⅠthinmarginallayerLamina

ⅡSubstantiagelatinosaSubstanceP,aneuropep-tideinvolvedinpathwaysmediatingsensibilitytopain,isfoundinhighconcentrationsinlaminasIandII.Laminas

ⅢandⅣNucleuspropriusTheirmaininputisfromfibersthatconveypositionandlighttouchsense.LaminaVcontainscellsthatrespondtobothnoxiousandvisceralafferentstimuli.reticularformation

LaminaVIcontainsneuronsthatrespondtomechanicalsignalsfromjointsandskin.

Rexed’slaminaPosteriorhornreticularformationLaminaⅦIntermediate

zone.Nucleusthoracicus(dorsalnucleus)(Clarke‘scolumn)(C8~L3),thatgiverisetotheposeriorspinocerebellartract.Intermediolateralnucleus(T1~L3)Preganglionicsympatheticfibersprojectfromcellsinthisnucleus.IntermediomedialnucleusSacralparasympatheticnucleus(S2~S4)LaminasVIIIandIXAnteriorhorn.representmotorneurongroupsinthemedialandlateralportionsoftheventralgraycolumn.LaminaXThisrepresentsthesmallneuronsaroundthecentralcanaloritsremnants.

Rexed’slamina皮質(zhì)下結(jié)構(gòu)調(diào)節(jié)運(yùn)動的下行纖維感覺區(qū)運(yùn)動區(qū)錐體束與調(diào)節(jié)肌張力有關(guān)的下行束淺感覺傳入深感覺傳入(隨意運(yùn)動)大腦皮質(zhì)四肢肌軀干肌

Whitematter

白質(zhì)

containsthreekindsoffibers:ascending,descending,andfasciculuspropriusFasciculusgracilis薄束Fasciculuscuneatus楔束PosteriorspinocerebellartractAscending

tracts

上行纖維束Anteriorspinocerebellartract

Spinothalamictract脊髓丘腦束T4～5脊神經(jīng)節(jié)Ⅰ周圍突中樞突后根內(nèi)側(cè)部粗纖維下肢、軀干下部

Fasciculusgracilis薄束and

Fasciculuscuneatus楔束

楔薄束核Ⅱ肌腱關(guān)節(jié)上肢、軀干上部Thesetwotractsconductthekinestheticsenses(senseofpositionandmovement)andthediscriminatingtactilesenses(torecognizethesize,shapeandtexture).Spinocerebellartract脊髓小腦束conveysinformationtothecerebellumaboutlimbandjointposition（proprioception）.脊神經(jīng)節(jié)Ⅰ皮膚白質(zhì)前連合交叉脊髓丘腦束(前束粗觸)(側(cè)束痛溫)后角ⅠⅣⅤ層Ⅱ上升1—2節(jié)段粗觸痛溫由內(nèi)向外C，T，L，SdorsolateralfasciculusorLissauer'stract

Spinothalamictract脊髓丘腦束

一側(cè)脊髓丘腦束損傷：出現(xiàn)對側(cè)損傷平面1～2節(jié)以下的區(qū)域出現(xiàn)痛、溫覺的減退或消失。Ittransmitsinformationtothethalamusaboutpain,temperature,itchandcrudetouch.脊髓丘腦束(淺感覺)薄束、楔束(深感覺)NameLocationSiteoforiginTerminationFunctionFasciculusgracilisPosteriorfuniculusSpinalgangliabelowsegmentT5GracilenucleusConveyproprioceptiontwo-pointdiscrimination,andfinetouchsensationoftrunkandlimbsFasciculuscuneatusSpinalgangliaabovesegmentT4CuneatenucleusPosteriorspinocerebellartractsLateralfuniculusHomolateralⅦnucleusthoracicusCerebellumUnconsciousproprioceptionfromlowerlimbandlowerportionoftrunkAnteriorspinocerebellartractsContralateralLaminaeⅤ~ⅦSpinothalamictractsLateralandanteriorfuniculusLaminaeⅠ,Ⅳ~ⅦDorsalthalamusPain,temperatureandcrudetouchsensationoftrunkandlimbsLateralcorticospinaltract

皮質(zhì)脊髓側(cè)束AnteriorcorticospinaltractBarneRubrospinaltractReticulo-spinaltractVestibulospinaltractTectospinaltractMediallongitudinalfasciculus

Descending

tracts

下行纖維束

由內(nèi)向外C，T，L，S

功能：一側(cè)皮質(zhì)脊髓側(cè)束管理同側(cè)上、下肢?。灰粋?cè)皮質(zhì)脊髓前束支配雙側(cè)軀干肌的運(yùn)動。當(dāng)脊髓一側(cè)的皮質(zhì)脊髓側(cè)束損傷后，出現(xiàn)同側(cè)肢體的肌肉癱瘓（肌張力增高、腱反射亢進(jìn)、無肌肉萎縮、有病理反射征），而軀干肌不癱瘓。Corticospinaltract皮質(zhì)脊髓束LateralcorticospinaltractAnteriorcorticospinaltract

Barneanteriorcorticospinaltract

Name(tract)LocationSiteoforiginTerminationFunctionLateralcorticospinalLateralfuniculusCerebralcortexLaminaeⅣ~ⅨanteriorhornFinemotorfunctionGrossandposturalmotorfunctionAnteriorcorticospinalAnteriorfuniculusCerebralcortexRubrospinalLateralfuniculusContralateralrednucleusLaminaeV~ⅦExcitatoryofflexorsVestibulospinalAnteriorfuniculusHomolateralvestibularnucleiLaminaeⅦ~ⅧExcitatoryofextensorsReticulospinalAnteriorandlateralReticularformationLaminaeⅦ~ⅧModulationofsensorytransmissionandspinalreflexesMediallongitudinalfasciculusAnteriorfuniculusVestibularnucleiLaminaeⅦ~ⅧCoordinateneckwitheyemovementReflexheadturningTectospinalAnteriorfuniculusSuperiorcolliculusLaminaeⅥ~ⅧFasciculuspropriusAnterior,lateralandposteriorSpinalcordSpinalcordIntrinsicreflexmechanismofspinalcord

Fasciculusproprius固有束

Functionsofspinalcord⑴Conductionofexcitations⑵SpinalReflexes

Reflexesaresubconsciousstimulus-responsemechanisms.Thereflexesareextremelyimportantinthediagnosisandlocalizationofneurologiclesions.MonosynapticallyReflexes單突觸反射STRETCHREFLEXES牽張反射(alsocalledtendonreflexes腱反射ordeeptendonreflexes深反射)dependsonspecializedsensoryreceptors(musclespindles),afferentnervefibersextendingfromthesereceptorsviathedorsalrootstothespinalcord,twotypesofLMNs(alphaandgammamotorneurons)thatprojectbacktomuscle,andspecializedinhibitoryinterneurons(Renshawcells).PatellarreflexePOLYSYNAPTIC

REFLEXESSpinalcordtransection脊髓橫斷SpinalShock脊髓休克Thissyndromeresultsfromacutetransectionof,orsevereinjuryto,thespinalcordfromsuddenlossofstimulationfromhigherlevelsorfromanoverdoseofspinalanesthetic.Allbodysegmentsbelowtheleveloftheinjurybecomeparalyzedandhavenosensation;allreflexesbelowthelesion,includingautonomicreflexes,aresuppressed.Spinalshockisusuallytransient;itmaydisappearin3to6weeksandisfollowedbyaperiodofincreasedreflexresponse.SpinalcordlesionsHemisectionofthespinalcord

脊髓半橫斷Brown-SequardSyndromeSignsandsymptomsincludeipsilateralupper-motor-neuronparalysisbelowthelevelofthelesion(resultingfromdamagetothelateralcorticospinaltract);andipsilaterallossofproprioceptive,vibratory,andtwo-pointdiscriminationsensebelowthelevelofthelesion(resultingfromdamagetothedorsalcolumns).Thereisalsoacontralaterallossofpainandtemperaturesensebelowthelesion(resultingfromdamagetothespinothalamictracts,whichhavealreadydecussatedbelowthelesion).

1.損傷平面以下同側(cè)肢體硬癱（損傷了皮質(zhì)脊髓束）；2.損傷平面以下同側(cè)肢體位置覺、震動覺和精細(xì)觸覺喪失（損傷了后索內(nèi)的薄束和楔束）；3.損傷平面以下的對側(cè)身體痛、溫覺喪失（損傷了脊髓丘腦束）。

Acentrallesioncanaffectthedecussatingfibersofthespinothalamictractfrombothsideswithoutaffectingotherascendingordescendingtracts.Asaresult,theselesionscanproducedissociatedsensoryabnormalitieswithlossofpainandtemperaturesensibilityinappropriatedermatomesbutwithpreservedvibrationandpositionsense.Thisoccurs,forexample,insyringomyelia(脊髓空洞癥)

中央灰質(zhì)周圍病變：雙側(cè)節(jié)段性痛、溫覺消失（損傷了白質(zhì)前連合處的脊髓丘腦束）而本體感覺和精細(xì)觸覺無障礙（后索完好）。這種現(xiàn)象稱感覺分離。LesionaroundthecentralgraymatterLesionofanteriorhornofthespinalcord(脊髓灰質(zhì)炎)脊髓損傷的神經(jīng)生物學(xué)

急性脊髓損傷是一種后果極為嚴(yán)重的創(chuàng)傷，發(fā)達(dá)國家發(fā)生率為15-40/百萬人口；美國達(dá)30-70/百萬人口；我國約有40余萬脊髓損傷導(dǎo)致的截癱患者，每年增加約1萬人。脊髓損傷的病理改變及其機(jī)制

脊椎骨折或錯位壓迫、撞擊、牽拉或切割脊髓，脊髓損傷后數(shù)小時至數(shù)天內(nèi)，原發(fā)性損傷啟動一系列細(xì)胞和分子水平的生化級聯(lián)反應(yīng)，導(dǎo)致組織缺血、細(xì)胞死亡、軸突脫髓鞘等繼發(fā)性損傷，初始病變的程度逐漸加重、范圍持續(xù)擴(kuò)大，功能障礙的嚴(yán)重程度和范圍也隨之發(fā)展。損傷中心不可逆轉(zhuǎn)的原發(fā)性損傷：

1.被膜破壞，灰質(zhì)血管破裂出血，白質(zhì)水腫，

2.損傷中心出血性壞死

3.傷及脊髓節(jié)段和神經(jīng)傳導(dǎo)通路。

繼發(fā)性損傷是在細(xì)胞和分子水平上發(fā)生的主動調(diào)控過程，具有可逆轉(zhuǎn)及可調(diào)控性繼發(fā)性損傷的機(jī)制

星形膠質(zhì)細(xì)胞對損傷的反應(yīng)促進(jìn)膠質(zhì)瘢痕形成或抑制軸突生長的分子：硫酸軟骨素蛋白多糖CSPG,中樞神經(jīng)系統(tǒng)內(nèi)的髓鞘相關(guān)抑制蛋白Nogo是抑制神經(jīng)纖維生長的重要因素。

被激活的星形膠質(zhì)細(xì)胞在損傷區(qū)周邊聚集，逐漸形成膠質(zhì)瘢痕。星形膠質(zhì)細(xì)胞、寡突膠質(zhì)前體細(xì)胞、腦膜細(xì)胞和小膠質(zhì)細(xì)胞等多種細(xì)胞參與了瘢痕的形成。膠質(zhì)瘢痕雖然對損傷的脊髓組織具有一定的屏蔽保護(hù)作用，但卻形成嚴(yán)重阻礙軸突再生的屏障。長期以來，膠質(zhì)瘢痕一直被認(rèn)為是阻礙神經(jīng)纖維再生的機(jī)械性屏障，但這一傳統(tǒng)觀點(diǎn)目前正受到嚴(yán)峻的挑戰(zhàn)。在成年大鼠脊髓半切和全切損傷的研究中，盡管星形膠質(zhì)細(xì)胞在脊髓損傷中心區(qū)的周邊組織內(nèi)增生，且部分細(xì)胞突起相互交織形成疏松的網(wǎng)狀結(jié)構(gòu)，但并未形成足以對神經(jīng)纖維的再生造成完全阻礙的機(jī)械性屏障。膠質(zhì)瘢痕實(shí)質(zhì)內(nèi)已分離出CSPG及其他多種抑制軸突生長的化學(xué)物質(zhì)，這些化學(xué)物質(zhì)可能對軸突的再生形成化學(xué)性屏障，較機(jī)械性屏障有著更為強(qiáng)烈