呼吸系統(tǒng)生理

呼吸系統(tǒng)生理第1頁/共48頁Vocabulary第2頁/共48頁vocabularyrespiratory：呼吸respiration：呼吸expiration：呼氣inspiration：吸氣respiratorycenter：呼吸中樞respiratorymuscle：呼吸肌inspiratoryneurone：吸氣神經(jīng)元diaphragm：膈肌第3頁/共48頁upperairway：上呼吸道lung：肺pharynx：咽larynx：喉trachea：氣管bronchi：支氣管terminalbronchioles：終末支氣管respiratorybronchioles：呼吸性支氣管alveolar：肺泡vocabulary第4頁/共48頁intrapleuralpressure：胸內(nèi)壓functionalresidualcapacity（FRC）：機(jī)能余氣量vitalcapacity（VC）：肺活量forcedvitalcapacity（VC）：用力肺活量residualvolume（RV）：余氣量totallungcapacity（TLC）：肺總?cè)萘縞losingcapacity（CC）：閉合容量theminuteventilation：每分通氣量vocabulary第5頁/共48頁arterialcarbondioxidetension：動(dòng)脈血二氧化碳分壓arterialoxygentension：動(dòng)脈血氧分壓cerebrospinalfluid：腦脊液peripheralchemoreceptor：外周化學(xué)感受器centralchemoreceptor：中樞化學(xué)感受器respiratoryreflex：呼吸反射

vocabulary第6頁/共48頁laryngospasm：喉痙孿airwayobstruction：氣道阻塞compliance：順應(yīng)性surfactant：表面活性物質(zhì)surfacetension：表面張力hypoxicpulmonaryvasoconstriction：缺氧性肺血管收縮vocabulary第7頁/共48頁deadspace：無效腔anatomicaldeadspace：解剖無效腔respiratoryquotient：呼吸商oxyhaemoglobindissociationcurve：

氧離曲線Haldaneeffect：Haldane效應(yīng)Bohreffect：Bohr效應(yīng)secondgaseffect：第二氣體效應(yīng)vocabulary第8頁/共48頁1.1.1LungFunctions第9頁/共48頁肺通氣肺換氣氣體運(yùn)輸組織換氣氧化代謝第10頁/共48頁LungFunctionsLungsareasiteforgasexchangewiththeexternalenvironmentRegulationacid-basebalanceLungsareadefencemechanismLungsareabloodreservoirServeabiosyntheticfunction氣體交換外環(huán)境酸堿平衡貯血庫生物合成功能第11頁/共48頁

1.1.2LungStructure

第12頁/共48頁鼻腔喉氣管左主支氣管右主支氣管左肺右肺咽食道膈肌第13頁/共48頁氣管支氣管細(xì)支氣管終末細(xì)支氣管呼吸性細(xì)支氣管肺泡管肺泡囊

傳導(dǎo)單位呼吸單位第14頁/共48頁肺泡內(nèi)氣體肺泡內(nèi)氣體基底膜毛細(xì)血管內(nèi)皮組織間隙毛細(xì)血管內(nèi)血漿第15頁/共48頁1.2ControlofRespiration第16頁/共48頁中腦腦橋腦干呼吸中樞第17頁/共48頁頸動(dòng)脈體主動(dòng)脈體頸動(dòng)脈竇主動(dòng)脈第18頁/共48頁Respiration

CentralControl

PeripheralChemoreceptors

carotidandaorticbodies

Thecentralchemoreceptors

Lieinthefloorofthefourthventricleandareeithertheneuronesresponsibleforgenerationoftherespiratoryrhythmorarecloselyrelatedtothem.TheyarebestregardedassensorsofoxygendeliveryastheyrespondtobothadecreaseinPaCO2andinbloodflowrate.PeripheralControl

第四腦室呼吸節(jié)律頸動(dòng)脈體主動(dòng)脈體第19頁/共48頁1.3MechanicsofRespiration第20頁/共48頁1.3.1LungVolumes肺容量補(bǔ)吸氣量肺總?cè)萘坑鄽饬抗δ苡鄽饬砍睔饬垦a(bǔ)呼氣量第21頁/共48頁1.3.2ComplianceBoththelungsandthechestwallrequireadistendingforce,usuallyexpressedasvolumechangeperunitofdistendingpressure:compliance

Thecomplianceisapproximatelylinearovermostoftherange,butislesswhenthelungissmallandnearlyfullyinflated.

Thelungexhibitshysteresis,i.e.thecompliancediffersduringinflationanddeflation.Thisisduetotheeffectofalveolarsurfactantandisabsentifthelungisinflatedwithafluid.順應(yīng)性滯后肺表面活性物質(zhì)第22頁/共48頁LawofLaplace：P：回縮壓力P=2T/rT：肺泡表面張力

r:肺泡半徑Ifthealveoliareregardedasaseriesofinterconnectedbubblesthenthenormalsurfacetensioneffectswouldensurethatthesmallerbubblesemptiedintothelarger.1.3.3Surfactant第23頁/共48頁Infact,itdoesn’t!thepresenceofasurfaceactivematerial,secretedbythetypeIIalveolarcells,ensuresthatthisdoesnotoccur.表面活性物質(zhì)第24頁/共48頁1.3.4ResistanceTheflowofairintoandoutofthelungsisopposedbythefrictionalresistanceoftheairwaysThetypeofflowisimportant,withlaminarflowofferinglessresistancethantransitionalorturbulentflow.Laminarflowoccursatlowflowratesandinthesmallerbronchi.Inthelargerairwaysandatbranchesinthebronchialtree,turbulentflowmayoccur.Airwayresistanceisrelatedtolungvolume,decreasingasthelungexpands.Itisalsorelatedtobronchomotortoneandthethicknessofthemucosallayer.阻力摩擦阻力層流湍流粘膜層支氣管肌緊張(性)第25頁/共48頁1.4MatchingofVentilation

andPerfusion第26頁/共48頁1.4.1DistributionofPerfusionThedistributionofbloodflowwithinthelungsislargelyinfluencedbygravity.Intheerectposturethreedistinctzonesmaybedescribedasthreezones.Intheupperzone,thereisalmostnoflow.Inthemiddlezoneandthelowerzone,flowincreasesinthemoredependentareas.分配灌流重力第27頁/共48頁1.4.2DistributionofVentilationSeveralfactorsensurethattheinspiredgasisdirectedtowardsthedependentpartsofthelungs.Themajorfactoristhecomplianceofthedifferentpartsofthelung.Thedifferentpartsofthelungareondifferentpartsofthecompliancecurve.通氣順應(yīng)性第28頁/共48頁1.4.3Ventilation:perfusionratioNormalgasexchangerepuiresboththatalveoliareadequatelyventilatedandthattheyareperfusedwithpulmonarybloodatanappropriaterate.VA/Q=AlveolarventilationratePulmonarybloodflow通氣/血流比值肺泡肺血流量第29頁/共48頁Anareaofthelungisperfusedbutinadequatelyventilated,VA/Qwillobviouslybereduced.Asaresult,thealveolarPO2fallsandthePCO2rises.Wherealveoliareventilatedbutnotproperlyperfused,VA/Qwillbeincreases.theyaddtothephysiologicaldeadspace.Intheabsenceofgasdiffusioninandoutofthepulmonaryblood,alveolarPO2risesandPCO2falls.生理無效腔第30頁/共48頁1.4.4DeadSpaceThedeadspaceoftherespiratorysystemisthatpartwhichdoesnotparticipateingasexchange.Itcomprisestheanatomicaldeadspace,theupperairwayandtracheobronchialtreedowntotherespiratorybronchioles.Themoreusefulmeasureistheratioofdeadspace（Vd）totidalvolume（Vt）.Theratioisabout0.3undernormalcircumstances.無效腔解剖無效腔支氣管樹第31頁/共48頁1.5GasExchangeandCarriage第32頁/共48頁肺換氣組織換氣第33頁/共48頁肺泡組織細(xì)胞氧分子血紅蛋白氧合血紅蛋白Oxygentransport氧氣的運(yùn)輸?shù)?4頁/共48頁波爾效應(yīng)第35頁/共48頁

CarbonDioxidetransportCarbondioxidepassesinareversecascadefrommitochondriatoatmosphere.Itismuchmorewatersolublethanoxygenanddiffusesmorereadily.Carbondioxideismostlycarriedinthebloodasbicarbonateion（HCO3-）.二氧化碳的運(yùn)輸線粒體擴(kuò)散碳酸氫根離子第36頁/共48頁Thehydrogenionisbufferedbyprotein,predominantlyreducedhaemoglobin

（Haldaneeffect）andtheHCO3-diffusesintotheredcellinexchangeforchloride.ThereverseoccursinthelungsasCO2iseliminated.血紅蛋白氫離子氯離子第37頁/共48頁1.6EffectsofAnesthesiaonRespiration第38頁/共48頁ControlofRespirationMechanicsofRespirationMatchingofVentilationandPerfusionGasexchangeandCarriageIncreasedOxygenConsumptionSecondGasEffect

氧耗第二氣體效應(yīng)第39頁/共48頁1.6.1ControlofRespirationThevolatileandintravenousanaesthetic

agentsandtheopioidanalgesicsalldepressrespirationanddecreasetheresponsivenesstoCO2.Otherrespiratoryresponsessuchascougharereducedduringanaesthesia.Thepatternofrespirationduringanaesthesiatendstoberegular.麻醉藥鎮(zhèn)痛藥第40頁/共48頁1.6.2MechanicsofRespiration

TheinductionofanaesthesiaresultsinareductionintheFRCofabout0.5litre,probablyduetocranialdisplacementofthediaphragm.Thiseffectisgreatestafterneuromuscularblockade.膈肌頂位置改變肌松藥麻醉誘導(dǎo)機(jī)械通氣第41頁/共48頁1.6.3MatchingofVentilationandPerfusion

Inductionofanaesthesiadoesnotaffectthedistributionofperfusionexceptthattheincreasedintrathoracicpressureofmechanicalventilationmayreducecardiacoutputandincreaseorcreatethezoneinthelungwherealveolarpressureexceedspulmonaryarterialpressure,thusincreasingdeadspace.胸內(nèi)壓肺動(dòng)脈壓肺泡壓第42頁/共48頁Thedistributionofventilationisimpairedduringspontaneousrespirationandworsenedwithmechanicalventilationwhenthereisareductionintheventilationtothedependentpartsofthelung.自主呼吸機(jī)械通氣第43頁/共48頁1.6.4GasexchangeandCarriageGasexchangeisimpairedduringanaesthesiaasoutlinedaboveandoxygencarriagemaybeimpairedbythereducedcardiacoutput.ByreducingthePaCO2

hyperventilation