感觉系统症状.ppt

感觉神经系统症状,郑州大学第一附属医院神经内科苗旺,GENERALPROPERTIESOFSENSORYSYSTEMS,Figure10-4:Sensorypathways,1.SENSORYRECEPTORS,A:Freenerveendings(pain,temperature)B:Paciniancorpuscle(pressure)C:Meissnerscorpuscle(touch)D:Musclespindle(stretch),SENSORYRECEPTORTYPES,Figure10-1:Sensoryreceptors,Ruffinisendingsrespondtotensionandstretchintheskin,SEGMENTALINNERVATION(DERMATOMES)PERIPHERALINNERVATION,感觉传导路由三级神经元组成：第级神经元:胞体位于脊髓后根神经节或脑神经感觉神经节第级神经元:胞体位于脊髓后角细胞及延髓薄束核、楔束核或脑干脑神经核第级神经元:胞体位于丘脑感觉接替核,SPINOTHALAMICPATHWAY,Carriespain,temperature,touchandpressuresignals1stneuronentersspinalcordthroughdorsalroot2ndneuroncrossesoverinspinalcord;ascendstothalamus3rdneuronprojectsfromthalamustosomatosensorycortex,2.浅感觉传导路:前外侧系统theanterolateralsystem(先交叉，后上行)轻触-压觉,痛觉,温度觉的传入纤维经后根节外侧部(细纤维部分)进入脊髓后角并于此换元换元后的第级神经元发出纤维在中央管前交叉到对侧沿脊髓丘脑前束、脊髓丘脑侧束上行到达丘脑感觉接替核,SOMATICPATHWAYS,Figure10-9:Sensorypathwayscrossthebodysmidline,SpinothalamicPathway,Smallsensoryfibres:Pain,temperature,sometouch,Primarysomatosensorycortex(S1),Thalamus,Medulla,Spinalcord,Spinothalamictract,ImpulsestransmittedtospinalcordbyMyelinatedAnerves:fastpain(80m/s)UnmyelinatedCnerves:slowpain(0.4m/s),Impulsesascendtosomatosensorycortexvia:Spinothalamicpathway(fastpain)Reticularformation(slowpain),SPINOTHALAMICDAMAGE,请同学们屈起右腿右手放在桌子上闭上眼睛按指令完成动作,2.2DORSALCOLUMNPATHWAY,Carriesfinetouch,vibrationandconsciousproprioceptionsignals1stneuronentersspinalcordthroughdorsalroot;ascendstomedulla(brainstem)2ndneuroncrossesoverinmedulla;ascendstothalamus3rdneuronprojectstosomatosensorycortex,三者的传入冲动经后根节外侧部(粗纤维部分)进入脊髓后角沿同侧后索上行抵达延髓下部在薄束核、楔束核换神经元换元后的第级神经元发出纤维交叉到对侧沿内侧丘系到达丘脑感觉接替核。,dorsalcloumnpathway,Dorsalcolumnpathway,Largesensorynerves:Touch,vibration,two-pointdiscrimination,proprioception,Primarysomatosensorycortex(S1)inparietallobe,Thalamus,Medulla,Mediallemniscus,Spinalcord,Dorsalcolumn,Dorsalcolumnnuclei,TWO-POINTDISCRIMINATION,SENSORYMODALITY,Figure10-3:Two-pointdiscrimination,SENSORYMODALITY,Figure10-6:Lateralinhibition,DORSALCOLUMNDAMAGE,DORSALCOLUMNDAMAGE,SensoryataxiaPatientstaggers;cannotperceivepositionormovementoflegsVisualclueshelpmovement,由于传导痛觉、温度觉的传入纤维在进入脊髓后在进入水平的1-2个节段内更换神经元并交叉到对侧；而传导轻触(-压)觉的传入纤维在进入脊髓后分成上行和下行纤维，分别在多个节段内更换神经元并交叉到对侧，因而发生上述痛、温觉受损而触觉保留现象。,3.头面部的感觉传导路：Facialsensorypathway,触觉、本体感觉的传入冲动三叉神经主核、中脑核中继换元,痛觉、温度觉的传入冲动三叉神经脊束核中继换元,发出第级纤维越至对侧三叉丘系丘脑后内侧腹核,SENSORYSYNDROMES1.,Peripheralnerve:accordingtothedistributionareaoftheaffectednervePolyneuropathy:glovestockingdistribution,morepronaunceddistaly,moreonthelowerextremitiesDorsalrootgangliaorradicularlaesions:segmental,localisedtodermatomes,SENSORYSYNDROMES2.,Spinalcord:-completecordlesion-hemisectionofspinalcord:BrownSequardsyndrome-centralcordlesion(Syringomyelia,dissociatedsensoryloss:lossofpainandtemperature,preservationofproprioception)-posteriortractlesion(funicularmyelosis:lossofproprioception,ataxia)-conuslaesion(sensorylossofsacralarea,“saddleanaesthesia)Brainstem:WallenbergsyndromeThalamus:DejerineRoussysyndrome(contralateralhemihypaesthesia,ataxia,pain)Sensorycortex:contralateral