motorpathway运动通路(定)课件

MotorpathwayDr.WangfanMotorpathwayDr.Wangfan1Themotorneuronesthatdirectlyinnervateskeletalmusclehavecellbodieslyinginthegraymatterofthespinalcordandbrainstemandsometimereferredtoaslowermotorneurones.Theyconstitutethefinalcommonpathwaybywhichthenervoussystemcontrolsmovement.Incontrast,theneuronesformingthedescendingtracts,whichcontroltheactivityoflowermotorneurones,arethemselvescollectivelyreferredtoasuppermotorneurones..

twoimportantconceptsThemotorneuronesthatdirec2Thereareanumberofsuchdescendingtracts,amongthemostimportantbeingthecortocospinalandcortiobulbartracts.Themotorpathwaysincludepyramidalandextrapyramidalsystems.Thereareanumberofsuchdes3Thepyramidalsystem:Themainfunctionofthecorticobularandcorticospinalpathwayisthecontrolofvoluntary,skilledmovements.So,thisdescendingpathwayarecalledpyramidalsystemmotorpathway运动通路(定)课件4Theextrapyramidalsystem:Numerousofbrainsstructuresapartfromthecorticospinalsystemareinvolvedinthecontrolofmovement,postureandmuscletone;thesearesometimescollectivelyknownasextrapyramidalpathway.Theyincludecertainnucleiinthebrainstem,suchasthevesticularnucleiandthereticularnuclei(reticularformation),andthebasalgangliaandrelatedsubcorticalnucleilocatedinthefronbrain.

VestibulospinaltractTectospinaltractRubrospinaltractReticulospinaltract

Theextrapyramidalsystem:51.Composedofneuronscalledpyramidalcells-axonsprojecttospinalcordandmakeupthevoluntarymotortractscalledcorticospinaltracts.2.arisingfromthegiantpyramidalcellsandcertainothersmallercellsofthesuperiorandmiddlepartsoftheprecentralgyrusandanteriorpartoftheparacentallobule.Cortocospinaltracts1.Composedofneuronscalledp63.coursetheposteriorlimbofinternalcapsule,intermediate3/5ofthecruscerebri,thebasilarpartofthepons.4.formthepyramidaldecussation(70-90%)andcontinuesasthelateralcorticospinaltractinoppositeside.5.uncrossedfibersformtheanteriorcorticospinaltract.3.coursetheposteriorlimbof73.coursetheposteriorlimbofinternalcapsule,intermediate3/5ofthecruscerebri,thebasilarpartofthepons.4.formthepyramidaldecussation(70-90%)andcontinuesasthelateralcorticospinaltractinoppositeside.5.uncrossedfibersformtheanteriorcorticospinaltract.3.coursetheposteriorlimbof86.thecorticospinaltractcontrolsmovementoftheupperandlowerlimbs.6.thecorticospinaltractcont9Thecorticobulbar(orcorticonuclear)tractisawhitematterpathwayconnectingthecerebralcortextothebrainstem(theterm"bulbar"referringtothebrainstem).The'bulb'isanarchaictermforthemedullaoblongata.Inclinicalusage,itincludestheponsaswell.Themusclesoftheface,headandneckarecontrolledbythecorticobulbarsystem,whichterminatesonmotorneuronswithinbrainstemmotornuclei.CorticobulbartractCorticobulbartract101.arisingfromtheinferiorpartoftheprecentralgyrus.2.coursethroughthegenuofinternalcapsuleandthebrainstem.3.givesrisetothecollateralstothebilateraloculomotor,trochlear,trigeminalmotor,ambiguus,accessorynucleiandsuperiorpartofthefacialnucleus,andtothecontralateralhypoglossalnucleusandtheinferiorpartofthefacialnucleus.CorticobulbartractCorticobulbartract113.givesrisetothecollateralstothebilateraloculomotor,trochlear,trigeminalmotor,ambiguus,accessorynucleiandsuperiorpartofthefacialnucleus,andtothecontralateralhypoglossalnucleusandtheinferiorpartofthefacialnucleus.CorticobulbartractCorticobulbartract12

Ifdamageofrightinternalcapsule,thenresultsinseriousneurologicdeficits.corticospinaltract

--leftlesionofvoluntarymotorparalysis(upperandlowerlimbs)Corticobulbartract--leftlesionofvoluntarymotorparalysisincludingfacialexpressionandtonguemuscles(rightinferiorpartofthefacialnucleusandhypoglossalnucleusarecontroledbycontralateralCorticobulbartract

).Whathappenedinsensorypathway?(nextweek)Ifdamageofrightinternal13Supranuclearparalysis(spastic\hardparalysis)—damageofuppermotorneuronesInfrannuclearparalysis(flaccid\softparalysis)—damageoflowermotorneuronesTheyaredifferentsymptomTendonreflexTonicityofmusclesPathologicalreflexMusclesatrophySupranuclearparalysis(spasti14hardparalysissoftparalysisTendonreflex＋＋＋－Tonicityofmuscles＋＋＋－Pathologicalreflex＋＋＋－Musclesatrophy－＋＋Differencesofhardandsoftparalysishardpa15Supranuclearparalysis(spasticparalysisorhardparalysis)Infranuclearparalysis(flaccidparalysisorsoftparalysis)Thispatientwithrightfacialnerveparalysiscannotclosetherighteye.Onsmiling,therightsideofhisfaceisimmobile.Heisunabletowrnkletheforehead.Thispatientwithrightfacialnerveparalysiscannotclosetherighteye.Onsmiling,therightsideofhisfaceisimmobilewithaflattenednasolabialfold..damageofLeftfacialnervedamageofleftCorticobulbartractSupranuclearparalysisInfranu16Extendtongue,tineoftonguedeflectleftsideRightsideExtendtongue,tineoftongue17Extrapyramidalsystem

Theextrapyramidalsystemisacommonnameofthedescendingpathwaysexceptthepyramidalsystem.

rubrospinaltracttectospinaltractvestibulospinaltractreticulasopinaltract

cortico-neostriatum-dorsothalamus-cortexcircuit

corticoponto-cerebellar-cortex-circuitNeostriatum-sustantianigracircuitExtrapyramidalsystem18

TheextrapyramidalsystemMainfunctions:1.Regulatethetonicityofthemuscles.2.Coordinatethemuscularactivities.3.Maintainthenormalbodypostureandproducehabitualandrhythmicmovements.Theextrapyramidalsystem19motorpathway运动通路(定)课件201.Thecortico-neostriatedbody-dorsothalamus-cortexcircuitCorticalcellsCaudatenucleusandputamenGlobuspallidusVentroanteriornucleusandventrolateralnucleusSomatomotorareasofthecortexGlobuspallidusreturn1.Thecortico-neostriatedbod212.Thecorticoponto-cerebellar-cortexcircuitPyramidcellsofthecortexPontinenucleiNeocortexofthecerebellumThedentatenucleusVentrolateralnucleusofthethalamusrednucleusPrecentralmotorareaofthecerebralcortexThemotorcellsoftheanteriorhornofthespinalcordThedentatenucleus2.Thecorticoponto-cerebellar22

Ifdamageofrightinternalcapsule,thenresultsinse