案例成果生理学9sensory organ

CHAPTERTHESENSORYZeGangMa 感感受神感感受神刺神经(somatic,painmusclestretch,jointmovement)Special:vision,hearing,balance,smell,tasteSectionGeneralPrinciplesofSensoryOrgans一、DefinitionsandReceptors:structuresthatmonitorbothexternalandinternalconditionsandconductinformationaboutthosestimulitothecentralnervous感觉神在露的神经末梢周织构成的被膜样 环层小Pacinian

触觉Messner’s

肌Muscle感 ：感受细胞连同他们的附属结ReceptorClassificationbyRespondRespondtostimuliarisingoutsidethebody;Includetouch,pressure,pain,andtemperaturereceptorsintheskinandmostreceptorsofthespecialsenses(vision,hearingequilibrium,smell,taste)Visceroceptors:Visceroceptors:FoundininternalvisceraandbloodProprioceptors:Foundinskeletalmuscles,tendons,joints,ligamentsMechanoreceptors–respondtotouch,pressure,vibration,stretch,anditchThermoreceptors–sensitivetochangesintemperaturePhotoreceptors–respondtolightenergy(e.g.,retina)Chemoreceptors–respondtochemicals(e.g.,smell,taste,changesinbloodchemistry)Nociceptors–sensitivetopain-causingSensoryReceptorsAdequateAdequate敏感，这种形式的刺激称为该感受器的适为发生器电位（generatorpotential）GeneratorandActionPotentialattheTriggerZone

Themembraneofthereceptorregionis,however,electricallyinexcitable;itcontainsnovoltage-gatedionicchannelsanddoesnotgenerate es.Ifthereceptorregiongeneratedactionpotentials,thegradednatureofthegeneratorpotentialwouldbedestroyedbecauseassoonasthegeneratorpotentialexceededthecriticalfiringlevel,anactionpotentialwouldbeinitiated,reversingthemembranepolarizationnomatterhowlargeorsmallthestimulus,i.e.,themembranepotentialwouldnolongerencodethestimulusintensity.特定的刺激－特定的感受器特定的传入途径－特定的

变参与活动的神经纤维数目来实快适应感受慢适应感受举皮肤触觉感受肌梭、颈动脉窦、关节受特仅在刺激开始后率的轻微降低长时间维持在这一水平传入冲意递快速变化的信体探索新异的物体 物有利于感受器和中枢再接受的刺SectionVisualFunctionoftheHowdoesthevisualsystemreceiveHowdoesthevisualsystemreceiveandprocessinformationfromtheenvironment? 一、Thelight-RefractingSystemofthe（一）OpticalPropertyoftheLight-RefractingSystemoftheEye（二）RefractionofLightintheEyeandReduced 但更为简单的等效光学系统或模型，称为简化眼（reducedeye）。（三 Farpointofvision:modationofthe反射modationofthePupilsPupillarymodationreflex/Nearreflexofpupil:当瞳孔对光反射Pupillarylightreflex：瞳孔的大小由于入射光量的互感性对光反射con lightreflex:瞳孔对光反射的效应是双模糊图像－－视皮层－－皮层中脑束－－正中－动眼神经核－－动眼神经－－双眼内直肌收－双眼球（四）Defectsin modationandLight （五）AqueousAqueoushumor二、FunctionalAnatomyoftheRetinaandTwoPhotoreceptorSystem（一）FunctionalAnatomyofthePigmentepithelia光感受器细胞Photoreceptorcell

Rodcell视杆细Conecell视锥细 Synaptic 双极细胞和神经节bipolarcellsandganglion5（二）RetinalPhotoreceptorRodssystem,ScotopicvisionConessystem,Photopicvision VisioninshadesofgrayHighsensitivityLowacuityNightMuchconvergenceinMorenumerousin

ColorvisionLowsensitivityHighacuityDayvisionLittleconvergenceinConcentratedinfovea视杆系 视锥系三种视色白昼活动分凹周汇聚现象视色 一种视色物 夜间活动动（三）MechanismofPhotoreceptionoftheRod1、PhotochemistryofRhodopsin

opsin+ 刺激的能力。此时人的视觉是依靠视锥系统来完成的，在视紫红质分解和再合成过程中，有一部分视黄醛被摄入不足，会影响人的暗视觉，引起夜盲症(nyctalopia)2、GenerationofReceptor暗电(darkGP:-30～- 超极化－感受器电 （四）TheConeSystemandColorTrichromatic色一种对全部颜色或某些颜色缺乏分辨能力的色觉。色、InformationProcessinthe四、Visual五、OtherVisual（一）VisualVisualacuityreferstotheclarityorclearnessone’svision,ameasureofhowwellsees.Thismaybethoughtofastheabilityoftheeyetoseefinedetail.lgIMAR视力LandoltlgIMARvisualacuitySnelleneye（二）DarkandLightDarkLight应应（三）Visual空间范围，称视野白>>红>颞侧/下方>鼻侧/（四）AfterImageandFusion物体相似，这种的视觉后效应称为视后像。上常能分辩出一次又一次的闪光。当闪光频增加到一定程度时，重复的闪光刺激可引起上（五）BinocularVisionandExpandvisualFunctionofBinocularExpandvisualFunctionofBinocularSectionFunctionoftheAuditory一、AuditoryThresholdandAuditorySensationAreaF:20—20000Hz, P:0.0002—1000dyne/cm2Fs:1000--3000Hz,Language:300—二、FunctionsoftheExternalPinna(earlobe):collectssoundwaveshelpstodistinguishthedirectionofExternalauditoryc:soundwavesconductionairpressureincrease 作用。L=2.5cm λ=ν三、FunctionsoftheMiddle鼓鼓听听骨Malleus锤骨Incus砧骨Stapes镫骨鼓鼓咽咽鼓增压作用：中耳传导的总增压效应为22.4鼓膜、镫骨肌能在声压过大时反射性收缩，增四、AirandOssicularAir

BoneOvalRoundAirOvalRoundAirintheMiddleearVibrationofendolymphinTympanicSoundSoundSoundExternalExternalauditoryVibrationoftemporalbone五、Functionsof（一）Anatomyof

ScalaReissner’s ScalamediaScalatympani－Spiral 螺旋器－Alightmicroscopicimageofahaircellisolatedfromtissuesnormallysurroundingit.Thishaircellisabout30mlong;thehairbundleisabout5mHaircellsconvertmechanicalenergyintoanelectricalenergythroughionchannelswhichopenandcloseinsyncwithsoundvibrations.•Thisslidefrom(A.J.Hudspeth,Science,230:745-752,（二）VibrationofBasilarMembraneandTravelingWaveTheoryCochlearRepresentationof

basilarceHighFrequencysoundscausevibrationnearovalwindowLowfrequencysoundscausevibrationnearhelicotrema

MembranevibratesatofSoundDifferentpartsofthebasilarmembranerespondmosttofrequencies:highfrequencyatbase;lowfrequencyat波范围和最大（三）TransductionFunctionofHair基底

毛细DIS CEMENTOFTHEBASILARMEMBRANETOWARDTHESCALAVESTIBULI(UPPER)RESULTSDEPOLARIZATIONOFTHEOHC-ASSOCIATEDWITHDECREASEOFOHCLENGTH CEMENTINTHEOPPOSITEDIRECTIONPRODUCESHYPERPOLARIZATIONANDANINCREASEINOHCLENGTHCochlearActualResponsetohighPassivePassivePassiveresponsecausedbymechanicalpropertiesmembranes(e.g.ActiveResponseiscausedbyouterhaircells,whichinjectenergybackintovibrationofcochlearmembranesInnerhairOuterhairCellNerve（四）ElectrophysiologyoftheEndocochlearorendolymphatic

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管内淋巴的电＋80mv左右，耳蜗内电位。血纹细胞Na-K依赖性钾低钠的离子Cochlearmicrophonicpotential,耳蜗微音器电位结构所记录到的与声波的频率和完全一致的电位变六、ActionPotentialinAuditory七、HearingSection4TheFunctionofVestibularOrganAdequateStimulus - 半规 脊的适宜刺激是正负角加速椭圆囊和球囊的适宜刺激是直线加速度运当 时动的方向一致使静纤毛朝向动纤毛的一侧作最大弯曲，由此而产生的传入信息为辨据。 同毛细