心的外形和腔内结构详解

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1、ContentsIntroductionLocation,relationship&shapeoftheheartInternalstructuresofheartchambersSeptumoftheheartIntroductiontoVascularSystemPart1Thevascularsystemisaclosednetworkofvesselsinthebody.Itissubdividedintothecardiovascularandthelymphaticsystems.Thecardiovascular

2、systemconsistsoftheblood,theheart,andthebloodvesselswhichincludethearteries,capillariesandveins.Ittransportsnumeroussubstancestoandfromcellsfortheirsurvivalandissometimescalledthecirculatorysystem.Thelymphaticsystemiscomposedoflymphatics,lymphoidtissueandlymphoidorg

3、ans.Ittransportsafluid(calledlymph)thathasescapedfrombloodvesselsbacktobloodstreamatthejunctionofthejugularandsubclavianveinsatbothsidesoftheneck.Thelymphaticsystemisanimmuneanddefensivesystemofthebody.CardiovascularSystemHeartArteriesCapillariesVeinsBloodCirculatio

4、nTheflowofbloodthroughthenetworkofthebloodvesselsinthebodyoverandoveragainiscalledbloodcirculation.Thebloodcirculationcanbedividedintotwoparts:systemiccirculationandpulmonarycirculation.Thesystemic(greater)circulationiscirculationofbloodthroughwhichbloodflowsfromlef

5、tventricleintotheaortaanditsbranchestoallpartsofthebody,andreturnstotherightatriumviathesuperiorandinferiorvenacava.Thesystemiccircuitcarriesoxygenatedbloodthroughoutthebodyandpicksupcarbondioxidefrombodytissues.Inthisprocess,bloodchangesfromarterialbloodtovenousblo

6、od;itscolorchangesfromscarlettodarkred.Bloodvesselsinthesystemiccircuitalso(1)pickupnutrientsfromthedigestivetractanddeliverthemtocellsthroughoutthebody,and(2)receivenitrogenouswastesfrombodycellsandtransportthemtothekidneysforeliminationintheurine.Thepulmonary(less

7、er)circulationisbloodcirculationthroughwhichbloodflowsfromtherightventricleintopulmonarytrunkanditsbranchestothelungs,andreturnstotheleftatriumviathepulmonaryveins.Whenbloodflowsthroughcapillariesinthelungs,itdischargescarbondioxideandpicksupoxygenfromthelungalveoli

8、.Sothebloodchangesbackfromvenousbloodtoarterialblood,itscolorchangesfromdarkredtoscarletaswell.Thearteriesandveinsofthepulmonarycircuithav