人體結(jié)構(gòu)與功能 12-Pain學習資料

痛Email：wangyue@Pain山東大學醫(yī)學院王越痛的概念Conceptsofpain

IASP:painisanunpleasantsensoryandemotionalexperienceassociatedwithactualorpotentialtissuedamage,ordescribedintermsofsuchdamage痛是與現(xiàn)實的或可能的組織損傷有關(guān)的一種不愉快的感覺和情緒性反應(yīng)包括痛感覺和痛反應(yīng)ContentsPainpathwaysPainmodulationPainpathways

FIRSTSTEP-----Transduction:theconversionoftheenergyfromanoxiousthermal,mechanical,orchemicalstimulusintoelectricalenergy(nerveimpulses)Byoneofthesomaticsensoryreceptorscallednociceptors（傷害性感受器）Presentinmostbodytissues,includingskin,bone,muscle,mostinternalorgans,bloodvessels,andtheheart,butnotinthebrain.Nociceptorsarethefreeendingsof(primaryafferent)nervefibersdistributedthroughouttheperiphery.環(huán)層小體邁斯納小體梅克爾觸盤AdequateStimulationTemperature(>50℃or<1℃)Mechanicaldamage：強機械刺激，針尖刺敏感Chemicals(releasedfromdamagedtissue)激活傷害性感受器的致痛物質(zhì)損傷組織釋放的致痛化學物質(zhì)的來源：①直接從損傷細胞中溢出的，如K+、H+、histamine、ACh、5

HT和ATP等 ②在局部由損傷細胞的酶促合成的物質(zhì)，或通過血漿蛋白及白細胞游走帶入到損傷區(qū)的物質(zhì)。緩激肽(Bradykinin降解血漿蛋白，BK)和花生四烯酸的代謝產(chǎn)物，如前列腺素(Prostaglandins)和白細胞三烯(leukotrienes) ③由傷害性感受器本身釋放的致痛物質(zhì)，如substanceP

④神經(jīng)細胞及免疫細胞釋放的細胞因子：NGF，EGF,IL-1,IL-8,TNF

SECONDSTEP-----Transmittion：Nerveimpulsesgeneratedintheperipheryaretransmittedtothespinalcordandbraininseveralphases.a.Peripherytothespinalcord(trunksandlimbs)Painpathways

UnmyelinatedCfibersLightlymyelinatedAδfibersPrimaryafferentsSpreadslowlySpreadrapidlyFirstpain:fastsharpSecondpain:slowdullDorsalhorn(脊髓后角)CutaneousA

fibers:I、VCfibers:IIVisceralnociceptorafferents:I、V

PrimarycentralintegrationReferredpain（牽涉痛）PainoriginatingfromvisceralorgansperceivedascomingfromskinSiteofpainmaybedistantfromvisceralorgan是指內(nèi)臟疾病往往引起身體遠隔的體表部位發(fā)生疼痛的現(xiàn)象

GlutamateandsubstancePPrimaryneuronsSecondaryneuronsSubstancePGlutamateb.Spinalcordtothebrain:AscendingpainpathwaysDecussateandascendSpinothalamictract(STT)SpinalcordMedullaPonsThalamusMidbrainCerebrumSpinothalamicpathwayVentralposteriornucleusintralaminarnucleusDifferencebetweentouchandpainBeforereachthethalamus,someofthenociceptiveinformationaretransmittedtothereticularformation,mesencephalon,andhypothalamusSpinaltrigeminalnucleustrigeminalganglion

PainfromheadandneckPainmodulationPainmodulation：Segmentalantinociception:regulatedbyprimaryafferentinputsSubstantiagelatinosa, IIlayerFrombrainPIgatecontroltheory閘門控制學說(gatecontroltheory),MelzackandWall內(nèi)容：該學說主要集中在脊髓背角4類成份的相互作用

(1)無髓鞘的C傷害性傳入纖維

(2)有髓鞘的的Ab傳入纖維

(3)投射神經(jīng)元和抑制性中間神經(jīng)元

SG中的抑制性神經(jīng)元起著閘門的作用損傷引起C纖維緊張性活動使閘門打開,痛信息迅速上傳，當諸如輕揉皮膚等刺激興奮A傳入時，SG細胞興奮，從而關(guān)閉閘門，抑制投射細胞活動，減少或阻遏傷害性信息向中樞傳遞，使疼痛緩解跨皮電刺激神經(jīng)(transcutaneouselectricnervestimulationTENS)Painmodulation：Supraspinalantinociception:utilizedescendingpathwaysfromthebrainstemPainmodulation：Supraspinalantinociception:utilizedescendingpathwaysfromthebrainstem31DiscoveryaqueductofmidbrainPeriaqueductalgraymatter鄒岡中腦導水管周圍灰質(zhì)中縫大核Locus

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