医学ppt课件器官循环

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1、SECTION5ORGANCIRCULATION第五节器官循环Thebloodflowoforgandenpendson器官的血流量取决于：⒈Thedifferencebetweenaorticpressureandcentralvenouspressure主动脉压与中心静脉压之差⒉Thediastolicandsystolicstateofbloodvesselinthisorgan该器官阻力血管的舒缩状态I.CoronaryCirculation冠脉循环II.PulmonaryCirculation肺循环III.CerebralC

2、irculation脑循环I.CoronaryCirculation冠脉循环左冠状动脉右冠状动脉供血区域左心室前部左心室后部和左侧部和右心室回流途径冠状窦→心前静脉→右心房右心房Anatomicconsideration解剖特点①Thebolesandbranchesofleftandrightcoronaryarteryoftenpenetratemyocardiumindirectionperpendiculartocardiacsurface.左右冠状动脉主干分支垂直于心脏表面的方向穿入心肌。②Myocardialcapillary

3、distributionisextremelyabundance.心肌的毛细血管网分布极为丰富。③Collateralcoincidencebetweencoronaryisless.冠脉动脉之间的侧支吻合少。2.Physiologicalcharacteristicofcoronarycirculation冠脉循环的生理特点①Thepathwayisshortandbloodflowisfast途径短，血流快②Bloodpressureishigh血压较高③Bloodflowisbiganditis4%～5%ofcardiacoutpu

4、t血流量大,心输出量的4%～5%④Arteriovenousoxygendifferenceisgreatduringsilenceperiod平静时动-静脉血含氧量差很大⑤Bloodflowfluctuateswithcardiaccycle血流量随心动周期波动Isovolumiccontractionphase↓↓→rapidejectionphase↑→reducedejectionphase↓→diastolicphase(isovolumicrelaxationphase)等容收缩期↓↓→快速射血期↑→减慢射血期↓→舒张期↑（等

5、容舒张期↑↑）Levelofarterialdiastolicpressureandsizeofdiastolicphaseareimportantfactorsofdeterminingcoronaryflow.动脉舒张压高低和舒张期长短是决定冠脉血流量的重要因素。Contractionandrelaxationimpactonrightventricleisnotsoobviousastoleftventricle.收缩及舒张对右心室的影响不及对左心室明显。3.Regulationofcoronarybloodflow.冠脉血流量的调

6、节Normalvalue:60-80ml/100g.min.静息血流量为60～80ml/100g.minExercise300-400ml/100g.min运动时血流量为300～400ml/100g.minO2consumption7-9ml/100g.min.O2extraction65-70%氧耗量为7～9ml/100g.min，占氧输出量的65～70%。(1)Regulationofmetaboiliclevelofmyocardiumtocoronaryflow心肌代谢水平对冠脉血流量的调节Metaboiliclevelofmyo

7、cardiumisanimportantfactor.心肌本身的代谢水平是最重要因素。①Theenergyformyocardialcontractionnearlyallcomesfromaerobicmetabolism.心肌收缩的能量几乎完全来自有氧代谢。②Consumedoxygenofmyocardiumislarge,oxygenintakemuch,oxygenuptakepotencylow.Sothedemandofmyocardiumtooxygenincreasemainlydependsoncoronarydist

8、ension.心肌耗氧量大，摄氧多，摄氧潜力低。故心肌对氧需求增加主要依赖冠脉扩张。③Myocardiumregionalmetabolicproductisthemainfactorwhic