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ChapterIVbloodcirculation内容简介:心脏的生物电活动心脏生理(CardiacPhysiology)心脏的泵血功能血管生理(vascularphysiology)心血管活动的调节SectionTwoMechanismofheartpumpSectionOverviewCardiaccircle;Processofheartpumpingblood;Estimationoffunctionofheartpumping;Cardiacreserve;Regulationofheartpumping;Heartrate,(HR)Thetimesofheartbeatinaminute.Normalvalue:60~100beats/minHR100b/m---TachycardiaHR60b/m---BradycardiaCardiaccircleDefinition:心脏一次收缩和舒张所构成的机械活动周期。Consistingofcontractionorsystole,relaxationordiastole.Thereisasequenceofsystoleanddiastoleoftheatriumandventricle.心房收缩是一次心动周期的开始。ContractionofventricleContractionofatriumWholeheartdiastolerelaxationofventriclecardiaccycleFirst,atriacontraction(0.1s)→then,ventriclescontraction(0.3s)→last,alltheheartrelaxation(0.4s);Atriacontractionandventriclescontractionarenotoccursimultaneously;Diastoleislongerthansystoleforboththeatriumandventricle.Cardiaccycle=60/HRHR↑,cardiaccycle↓;diastole↓moreapparently;TheprocessofheartpumpingVentricularsystole:isovolumiccontractionphase(1)ejectionphase:rapidejectionphase(2)reduceejectionphase(3)Ventriclesdiastole:isovolumicrelaxation(4)fillingphase:rapidfillingphase(5)reducedfillingphase(6)atrialsystole(7)TricuspidValveAorticsemilunarValvePulmonarysemilunarValveMitralValveVentricularSystoleDuration:0.05sPressure:aortaventriclesatriaValve:A-Vclosed,SemilunarclosedV-ventricles:notchangeBloodcurrentdirection:notflowCharacteristics:ventricularpressurerisesdrasticallyIsovolumetricventricularcontractionRapidVentricularEjectionDuration:0.1sPressure:ventriclesaortaValve:A-Vclosed,SemilunaropenedV-ventricles:decreaseBloodcurrentdirection:bloodejectedintoaortarapidlyCharacteristics:P-ventriclesreachpeakEjectingvolumeis2/3ofthetotalejectingVentricularSystoleReducedVentricularEjectionDuration:0.15sPressure:ventriclesaortaValve:A-Vclosed,SemilunaropenedV-ventricles:decreaseBloodcurrentdirection:bloodejectedintoaortaslowlyCharacteristics:Ejectingreliesonthemomentum(动量)ofbloodVentricularSystoleVentricularDiastoleDuration:0.06~0.08sPressure:aortaventriclesatriaValve:A-Vclosed,SemilunarclosedV-ventricles:notchangeBloodcurrent:notflowCharacteristics:ventriclespressuredecreasedrapidlyIsovolumetricventricularrelaxationVentricularDiastoleDuration:0.11sPressure:aortaventriclesatriaValve:A-Vopened,SemilunarclosedV-ventricles:increasesBloodcurrent:ventriclesfillwithbloodfromatriarapidlyCharacteristics:fillingvolumeis2/3ofthetotalfillingRapidventricularfillingVentricularDiastoleDuration:0.22sPressure:aortaventriclesatriaValve:A-Vopened,SemilunarclosedV-ventricles:increasesBloodcurrent:ventriclesfillwithbloodfromatriaslowly.ReducedventricularfillingVentricularDiastoleDuration:0.1sPressure:aortaatriaventriclesValve:A-Vopened,SemilunarclosedV-ventricles:increasesBloodcurrent:atriaejectingbloodtoventriclesCharacteristic:FinalphaseofventriclesfillingAdds10%-30%toventriclesvolumeAtrialsystolePVTHEPRESSURE-VOLUMELOOP充盈期等容收缩期射血期等容舒张期CardiacCycleAtrialSystoleMitralClosesIsovolumiccontract.AorticopensRapidEjectionReducedEjectionIsovolumicRelax.AorticclosesRapidVentricularFillingMitralopensReducedVentricularFillingAtrialSystole时相时间(s)压力变化二半尖月瓣瓣心内血流心室容积心室收缩期等容收缩期0.05室内压迅速上升,房内压室内压主A压关关无不变快速射血期0.10房内压室内压主A压关开室→主动脉(快)缩小减慢射血期0.15房内压室内压≤主A压关开室→主动脉(慢)缩小心室舒张期等容舒张期0.07室内压迅速上升,房内压室内压主A压关关无不变快速充盈期0.11房内压室内压主A压开关房→室(快)增大减慢充盈期0.22房内压室内压主A压开关房→室(慢)增大心房收缩期0.10房内压室内压主动脉压开关房→室增大SummaryThecontractionofventricularmusclesisthefundamentalreasonforthecardiacpumpingblood;Thedifferenceofpressureisthedirectpowerofcardiacpumpingblood;Theopenorcloseofthevalvesdeterminetheuni-directionalofbloodflow;左、右心室搏出量相等。Summary快速射血期末心室压力最大。减慢射血期内主动脉压力已高于心室内压力。减慢射血期末心室容积最小舒张末期心室容积最大。心室2/3血液充盈在快速充盈期完成,且是负压抽吸所致,10-30%的血量在心房收缩期完成。RoleofatrialonHeartPumpingAccommodatingandstoringbloodfromvein•FillingofventriclesdependmainlyonthediastoleofventriclesPrimarypumpTheAssessoffunctionofheartpumpingStrokevolume:isthevolumepumpedoutbyoneventriclewitheachbeat.=EDV–ESV=approximate125-55=70ml。Determinedbythecontractibilityofcardiacmuscle.Thestrokevolumeoftheleftventricleisthesameasthatoftherightventricle.EDVESVSVEjectionfractionThevalueisequaltothequotientbetweenthestrokevolumeandEDV.Isabout55-65%(70/125)inrestingstate.EjectionfractionisrelativeconstantasSVisalwaysproportionaltoEDV.%100EDVSVEFCardiacoutputCardiacoutputisthevolumepumpedoutbyeachventricleperminute.CO=SVxHRCOforthehealthyhumanadultatrest:5.25liters/min(4.5to6L/minforhealthymales)Thecardiacoutputoftheleftventricleisthesameasthatofrightventricle.Changewithbodyactivitiesandmetabolismcondition.CardiacindexCardiacindexisthecardiacoutputpersquaremeterofbodysurfaceareaNormalvaluesrangefrom3.0to3.5liter/min/m2(Foranadultwithaveragesize,bodysurfacearea1.6-1.7m2)Itvarieswithage,gender,metabolicstateofthebody.CardiacreserveCardiacreserveCardiacreservemeanstheabilitywhichcardiacoutputcanincreasewiththedemandoforganismmetabolism.=MaximumCO-minimalCOCardiacReserveIncluding:ReserveofSVandHRR
本文标题:第四章 血液循环2(生理学)
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