感觉系统症状1.ppt

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1、感觉神经系统症状郑州大学第一附属医院神经内科苗旺GeneralPropertiesofSensorySystemsFigure10-4:Sensorypathways1.SensoryreceptorsA:Freenerveendings(pain,temperature)B:Paciniancorpuscle(pressure)C:Meissner’scorpuscle(touch)D:Musclespindle(stretch)ABCDSensoryReceptorTypesFigure10-1:SensoryreceptorsRuffini's

2、endingsrespondtotensionandstretchintheskinSEGMENTALINNERVATION(DERMATOMES)PERIPHERALINNERVATION感觉传导路由三级神经元组成：第Ⅰ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Ⅱ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Ⅲ级神经元:胞体位于丘脑感觉接替核SpinothalamicpathwayCarriespain,temperature,touchandpressuresignals1stneuronentersspinalc

3、ordthroughdorsalroot2ndneuroncrossesoverinspinalcord;ascendstothalamus3rdneuronprojectsfromthalamustosomatosensorycortex2.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Ⅱ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SomaticPathwaysF

4、igure10-9:Sensorypathwayscrossthebody’smidlineSpinothalamicPathwaySmallsensoryfibres:Pain,temperature,sometouchPrimarysomatosensorycortex(S1)ThalamusMedullaSpinalcordSpinothalamictractImpulsestransmittedtospinalcordbyMyelinatedAδnerves:fastpain(80m/s)UnmyelinatedCnerves:slowpai

5、n(0.4m/s)nociceptornociceptorAδnerveCnervespinothalamicpathwaytoreticularformationImpulsesascendtosomatosensorycortexvia:Spinothalamicpathway(fastpain)Reticularformation(slowpain)reticularformationspinothalamicpathwaythalamussomato-sensorycortexSpinothalamicdamagespinothalamicp

6、athwayLeftspinalcordinjuryLossofsenseof:TouchPainWarmth/coldinrightleg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2.2DorsalcolumnpathwayCarriesfinetouch,vibrationandconsciousproprioceptionsignals1stneuronentersspinalcordthroughdorsalroot;ascendstomedulla(brainstem)2ndneuroncrossesoverinmedulla;a

7、scendstothalamus3rdneuronprojectstosomatosensorycortex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Ⅱ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。dorsalcloumnpathwayDorsalcolumnpathwayLargesensorynerves:Touch,vibration,two-pointdiscrimination,proprioceptionPrimarysomatosensor

8、ycortex(S1)inparietallobeThalamusMedullaMediallemniscu