呼吸生理与呼吸力学呼吸生理与呼吸力学首都儿科研究所宋国维www.f61.com儿科门户网站主要内容主要内容•肺换气•肺通气•呼吸力学TerminalairwayTerminalbronchioleAlveolarductRespiratorybronchiolesSmoothmuscleAlveoliPerfusionofthealveoliCapillariesTerminalbronchioleBranchofpulmonaryarteryAlveolusBranchofpulmonaryveinRespiratorybronchioleAlveolardesignAqueouslayerAqueousmacrophageLamellabody(storessurfactant)Typellpneumocyte-liningcell(producessurfactant)TypelLiningcellCapillaryCO2O2O2O2运输运输血浆溶解O21.5%（1mmHg0.003ml）血红蛋白结合O298.5%（1g1.34ml）CO2CO2运输运输血浆溶解CO27~10%化学结合CO220~30%（HbCO2)血浆HCO360~70%大气成分大气成分气体浓度%N278.6O220.9CO20.04H2O0.46气体分压气体分压•分压=总压x浓度(%)•大气压=760mmHg•氧分压=760x20.9=158.8mmHg•二氧化碳分压=760x0.04=0.30mmHg肺泡气体分压肺泡气体分压PACO2=40mmHgPAO2=(760-47)x20.9%-PACO2/呼吸商=150–50=100mmHg氧解离曲线氧解离曲线影响氧解离曲线因素影响氧解离曲线因素影响氧解离曲线因素影响氧解离曲线因素氧解离曲线位移的意义氧解离曲线位移的意义•PCO2曲线右移•PCO240mmHg80mmHgSO275%65%10%O2组织细胞•PCO2(肺内）SO2LungVentilation/PerfusionRatios•Functionally:–Alveoliatapexareunderperfused(overventilated).–Alveoliatthebaseareunderventilated(overperfused).Insertfig.16.24Figure16.24PO2=40PCO2=45NormalVA/QLowVA/QHighVA/QCO2=45PO2=150PCO2=0PO2=100PCO2=40PO2=150PCO2=0...VentilationPerfusionRatiosNoflowPO2=40PCO2=45LowVA/Q.NormalVA/Q.PO2=100PCO2=40HighVA/Q.PO2=150PCO2=0PO2(mmHg)PCO2(mmHg)5010015050BaseApex肺容量肺容量•潮气量(VT)•深吸气量（IC）•补呼气量（ERV）•肺活量(VC)•功能残气量(FRC)•残气量(RV)•肺总量(TLC)VTTotalLungCapacityExpiratoryReserveInspiratoryReserveFRCInspiratoryCapacityResidualVolumeVitalCapacityExpiratoryReserveResidualVolumeVitalCapacityVTTotalLungCapacityInspiratoryReserveFRCInspiratoryCapacityTLCRVRVICVTIRFRCERVC肺通气（肺通气（11））•解剖死腔•肺泡死腔•生理死腔(VD)=解剖死腔+肺泡死腔•VD=(PaCO2-PECO2)/PaCO2xVTPECO2:呼出气平均CO2浓度肺通气（肺通气（22））•肺通气量=VTxf•肺泡通气量=（VT–VD）xf•肺泡CO2浓度=CO2产量/肺泡通气量肺泡通气量PACO2PaCO2肺泡通气量PACO2PaCO2呼吸力学呼吸力学•弹性阻力•非弹性阻力•时间常数•内源性呼气末正压气体流动气体流动高压低压呼吸肌是动力呼吸肌是动力•克服弹性阻力肺泡弹力纤维表面张力•克服非弹性阻力MechanicsofBreathingMechanicsofBreathingFigure7-1FromJ.B.West,RespiratoryPhysiology:TheEssentials(8thed.),2008,usedwithpermissionbyLippincottWilliams&WilkinsAnatomyofPleuralSacTakenfromSherwood,HumanPhysiology:FromCellstoSystems,5thEdAirliquidSURFACEPolarH2OmoleculesattractSurfacetension肺表面张力肺表面张力表面张力液体薄层肺泡腔液面压力where:P=pressureST=surfacetensionr=radiusofthebubbleP=2ST/rLaplaceslawP=2x1=0.210P=2x1=0.45105ConnectedbubblesAlveoliasbubblesFigure7-7FromJ.B.West,RespiratoryPhysiology:TheEssentials(8thed.),2008,usedwithpermissionbyLippincottWilliams&WilkinsFigure7-3FromJ.B.West,RespiratoryPhysiology:TheEssentials(8thed.),2008,usedwithpermissionbyLippincottWilliams&WilkinsSalineAirVonNeergaardFigure7-5FromJ.B.West,RespiratoryPhysiology:TheEssentials(8thed.),2008,usedwithpermissionbyLippincottWilliams&Wilkins呼吸压力呼吸压力•胸内压胸膜腔内的压力•肺内压肺泡内压力•经胸廓压肺内压与体表压之差值•经肺压肺内压与胸内压之差值•经胸壁压胸内压与体表压之差值PA(cmH2O)+1-10+0.5-0.50AirFlow(L/s)1234time(sec)-5-8Ppl(cmH2O)ThelinearDashedtraceisthePplrequiredtoovercomerecoilforces.MorePpl(s...
