医学机能实验学报告蛙心灌流英文

PAGEPAGE6LaboratoryReport本组承诺：本实验报告原创，绝无抄袭！组员：Effectsofchemicalsubstancesontheactivityoftheisolatedtoadheart【Purpose】Toobservetheeffectsofthreeions(sodium,potassium,calcium)andtwochemicalsubstances(acetylcholineandadrenaline)ontheactivityofthetoadheartinvitro.【Animal】Toad.【Method】1.PreparationoftheisolatedheartTakeatoad,afterdestoryingitsbrainandspinalcord,fixitonthetoadplateonback,openthethoraciccavity,cutpericardiumtoexposetheheart.Then,putonelineunderaortamakingaslipknotatthesuperiorextremityoftheleftaorta,isusedtotowwhenintubation.Shearareversed“V”shapedincisionwithophthalmologicalscissorsatrootofleftaorta,insertapropercannulaoftoadheartthatcontainsRinger’ssolutionintothearteryconefromthecutposition.Thenmakeadeadknot.Holdupthecannulagentlytoraiseheart,makealigationattheboundaryofthevenoussinusandthevenacava.Finally,cutoffaortasandthevenacava,dissociatetheheartfromthetoad.2.ApparatusinstallmentAtfirst,clampthecanulawithawoodentubeclip,thenthewoodentubeclipisfixedontheironbracketbyadoublecaveclamp.Clampthetipoftheheartatventriclediastolewithatoadheartclipthatislinkedwithalonglineintheotherend,thenlinkthelinetotheadaptivebridgeinthetensiontransducer.Regulatethepositionofthepulleysothatthetensilityoflineisappropriate.3.Observationitems(1).Recordthenormalcurveoftherelaxationandconstrictionoftheisolatedheart.(2).AftertheRinger’ssolutionincannulaisallreplacedby0.65%Nacl,observethechangeoftheheartbeat.(3).TakeouttheNacl,washitseveraltimesrepearedlywithfreshRinger’ssolution.Whentheheartbeatrecoverstonormaladd2%Cacl22dropstotheRinger’ssolutioninthecannula,observethechangeoftheheartbeat.(4).TakeouttheRinger’ssolutionincludingCacl2,washitseveraltimesrepearedlywithfreshRinger’ssolution.Afterthecurverecovertonormal,add1%KCL2dropsintheRinger’ssolutioninthecannula,observethechangeoftheheartbeat.(5).TakeouttheRinger’ssolutionincludingKcl,washitseveraltimesrepearedlywithfreshRinger’ssolution.Afterthecurverecovertonormal,add1:1000adenaline2dropsintheRinger’ssolutioninthecannula,observethechangeoftheheartbeat.(6)..TakeouttheRinger’ssolutionincludingadenaline,washitseveraltimesrepearedlywithfreshRinger’ssolution.Afterthecurverecovertonormal,add1:1000ACh2dropsintheRinger’ssolutioninthecannula,observethechangeoftheheartbeat.【Result】ContractionscopeContractionfrequencynormalK+↓↓Ca2+↓↓Na+↓↓AD↑↑ACh↓↓Theimageisinthelast.【Discussion】1.Thenormalheartrhythmactivitiesrequireasuitableenvironment,changesintheenvironmenthasadirectimpactonthenormalactivityoftheheart.Thisexperimentinfrogheartofperfusionfluidtojoinsomeofthematerialchangeintheenvironmentofcardiacactivity,observethechangesincardiacevents.2.CardiacmusclecellsclassificationContractilityExcitabilityConductivityautorhythmicitynon-autorhythmiccellHasHasHasDoesn’thaveautorhythmiccellDoesn’thaveHasHasHas3.Fastreactioncell(Atria,ventricular,Purkinjecells):mainlyconsistsofsodiumchannelisactivated,Nafastflowtriggeredactionpotential.Slowreactioncell(sinuscells,atrioventricularjunctioncell):mainlybyslowcalciumchannelisactivated,Caraisesactionpotentialsinthestream,gototheveryslow4.Myocardialcellphysiologicalcharacteristics:（1）Electrophysiologicalcharacteristics:self-discipline,excitability,conductive（2）Machineryphysiologicalcharacteristics:shrinkage5.Factorsaffectingcardiaccellexcitability(ventricularmyocytes)Impactfactorofcardiomyocyteself-discipline(sinuscells)Impactmyocardialcellconductivefactors(atrioventricularjunctioncells)1.StateofNachannel2.DifferenceRestingpotentiallevelandthresholdpotential1.Depolarizationspeedof4phase2.Differencebetweenmaximumbipolarvoltagelevelandthreshold1.diamete2.depolarizationamplitudeandspeedof0phase3.TheexcitabilityofadjacentpartsofthefilmMyocardialcellexcitation-contractioncouplingprocessesrequiredbytheCa2+totransitfromtheextracellularfluid,excitement,cellmembranesCa2+channel,therefore:extracellularCa2+concentration↑——cellexcitedinnerflowCa2+↑——myocardialcontractility↑,andviceversa.6.1％KClModerateandhighpotassium:ExtracellularK+,K+andCa2+inacompetitiveinhibitionofcell-membrane——K+inhibitorsonCa2+transport——entertheintracellularCa2+↓——cardiacexcitation-contractionwiththeprocessofweakening——myocardialcontractility↓(1)↑[K+]——K+concentrationgradientreducesbetweeninsideandoutside——restingpotentialabsolutevaluedecrease——excitatory↑(2)↑[K+]——cellmembranepermeabilityincreasesonK+——K+channelinactivatingspeed↓——automaticdepolarizationspeed↓——autorhythmicity↓(3)↑[K+]——cellmembranepermeabilityincreasesonK+——K+outflowincrease——maximumrepolarizationpotential↑——autorhythmicity↓(4)↑[K+]——inhibitionofinternalflowbyCa2+——depolarizationamplitudeandspeedof0phasereduce——conductivitylower.Severehighpotassium:[K+]↑↑——RP↓——Na+channelinactivation——excitatorylose.7.2％CaCl2Na+andCa2+inoutermembranehavecompetitiveinhibitionConcentrationofextracellularCa2+↑——Ca2+flow↑whencellsexcite——myocardialcontractility↑Fastreactioncell:highCa2+——inhibitNa+innerflow——0periodDepolarisationspeedandmagnitudedownward——conductivity↓Slowreactioncell:highCa2+——Ca2+enterintocellseasily,Ca2+flowincrease——0periodDepolarisationspeedincrease——conductivity↑8.O.65％NaClExtracellularCa2+↓——Ca2+flow↓in2phase——CytosolicCa2+concentration↓——myocardialcontractility↓[Ca2+]↓——Ca2+innerflowreduction——depolarisationslowsin0phase——conductive↓[Ca2+]↓——Ca2+isnoteasytoenterthecells——automaticdepolarizationspeedisslowin4phase——autorhythmicity↓9.ADAdrenalineconbinesmyocardialcellmembraneofβ-1receptors——myocardialcellsandsarcoplasmicreticulummembranepermeabilityofCa2+increases——sarcoplasmicCa2+concentrationincreases——myocardialcontractility↑.10.AChAcetylcholineconbinesMreceptorinmyocardialcel