e27.Development-of-circulat0ry-system循环系统发生(ppt文档).ppt

组织胚胎学课件组织胚胎学课件 七年制英文医学班专用七年制英文医学班专用中国医科大学中国医科大学基础医学院基础医学院组胚组胚英文教学组英文教学组Chapter 27 Development of circulatory system1.Formation of primitive cardiovascular system 1)extra-embryonicbloodvessels-bloodisland:atthemiddleof3rdweek,wallofthe yolk sac mesenchyma proliferate and formisolatedcellclusters,theperipheralcellbecomeflattenedanddifferentiateintoendothelialcelltofrom endothelial tube;central located cells aredetached and develop into primitive bloodcells(bloodstemcell)-endothelial tube approach and fuse witheach other to form an endothelial tubenetwork-endothelialtubenetworkappearsinchorionic membrane and body stalk,andconnecttovitellinecirculation2)intra-embryonicbloodvessels-by the 18-20th days,endothelial tubenetworkappearsinintraembryonicmesenchymatoformintraembryonicendothelialtubenetwork-bytheendof3rdweek,intraembryonicandextraembryonic endothelial tube networksconnect to each other to form a diffuseendothelialtubenetwork-endothelialtubenetworksfuseordisappeartoformprimitivecardiovascularsystem-primitivecardiovascularsystem:/hearttube:paired,bythe4thweek,whichfuse/arteries:-dorsalaorta:-vitellineartery-umbilicalartery-aorticarch:6pairs/veins:-anteriorcardinalvein-posteriorcardinalvein-commoncardinalvein-vitellinevein-umbilicalvein2.Development of heart 1)Formationofprimitiveheart-cardiogenicplate:proliferationofsplanchnicmesodermalcelltoformapairoflongitudinalcellcord,thendifferentiateintocardiactube-pericardiaccoelom:spaceinmesoderm-rapidgrowthofbrainvesiclespullsthebuccopharyngealmembrane,thecardiogenicplateandpericardiaccoelomforward-lateral foldsoftheembryo make thetwocardiactubeapproach and fusewitheachother-dorsalmesocardium:cardiactubeinvaginateintopericardiaccoelomandconnecttoitbydorsalmesocardium-themesodermadjacenttocardiactubedifferentiatesintothemyoepicardialmantle-cardiacjelly:gelatinoussubstancebetweenendothelialwallandmyoepicardialmantle,theninvadedbymesenchymalcell-heartwall:endocardium;myocardiumandepicardium2)Furtherdevelopmentoftheheart-singlecardiactubeconnectedcaudallyto the umbilical,vitelline and commoncardinalvein;cephalicallyconnectedtothe dorsal aortae by means of aorticarches-threedilatations:/bulbuscordis/ventricle/atrium-sinus venousus:dilatation which receivestheumbilical,vitelline,andcommoncardinalveins-truncusarteriosus:distalpartofthebulbuscordis,connectwithaorticsaccephalically-bulboventricularloop:bulboventricularportionofhearttubegrowsrapidly,bendsformingaloop-“U”-shapedheart;bulboventricularloopbendsinventral and caudaldirectionsandslightlytotheright-“S”-shapedheart:thehearttube continues togrow and bend,atriumshiftsindorso-cranialdirection;sinusvenousus locatedat caudal portionofatrium-atrioventricularcanal:atrioventricularjunctionremainsnarrow-thebulbuscordisdividedintothreeportions:/distalportion:truncusarteriosus/midportion:bulbusarteriosuscordis/proximal portion:develops into the rightventricle-primary ventricle develop into the leftventricle3)Partitioningoftheheartchambers-from27thdayto37thdaydivisionoftheatrioventricularcanal-endocardiaccushion:developasthickenings of subendocardial tissue in thedorsalandventralwallsoftheheart-theendocardialcushionsgrowtowardeachotherandfuse-lateralatrioventricularcushion:formatrioventricularvalvepartitioningoftheprimitiveatrium-septumprimum:athinsickle-shapedmembraneappearingfrom dorsocranial wallofatrium-foramenprimum:septum primum growstowardtheendocardialcushions,leaving anopeningbetweenitslower edge and theendocardialcushions-foramensecundum:theupperpartoftheseptumprimumperforatedandformanopening-septum secundum:another membraneappears in the ventrocranial wall in therightoftheseptumprimum-foramen ovale:oval passage betweenatrium,coveredbyvalveofforamenovale-beforebirth,bloodcanflowfromrightatriumtowardtheleftatrium-after birth,two septums fuse toseparateatriumcompletelypartitioningoftheprimitiveventricle-muscularpartofinterventricularseptum:bytheendof4th week,tissue ofventricular wall growstowardendocardialcushions,but left anopeningsocalledinterventricularforamen-membranous part of interventricularseptum:madeupofrightbulbarridge,leftbulbarridgeanddorsalendocardialcushiondivision of truncus arteriosus and bulbuscordis-right and left bulbar ridges:two spiralmesodermalridgesgrowfromtheinnerwallsof the truncus arteriosus and bulbus cordis,twist around each other and fuse to form aspiralaortico-pulmonaryseptum-bulbus arteriosus cordis and truncusarteriosusaredividesintotheaortaandthepulmonarytrunk3.Blood circulation of fetus and circulatory changes after birth1)bloodcirculatiooffetusumbilicalVductsvenosusorhepaticsinusinferior vena cava right atrium foramenovale left atrium leftventricleheadandneck region superiorvenacavarightatriumrightventricalductusarteriosusaortagutandlowerregionofthebodyumbilicalAplacenta2)circulatorychangesafterbirtha.umbilical V and ducts venousus:constrictandbecomesintoligamentumtereshepatisandligamentumvenosusb.umbilical A:becomes into medial umbilicalligament,but proximal portion persist assuperiorvesicalarteriesc.ductus arteriosus:constrict and becomearterialligamentd.foramenovaleclosed4.Congenital malformations 1)atrialseptaldefect:-patencyoftheforamenovale-foramensecundumdefect-foramenprimumeffect-endocardialcushiondefect2)ventricularseptaldefect:-membranous part of the ventricularseptumdefect-muscularpartoftheventricularseptum3)abnormalities of the truncus arteriosus andbulbusarteriosuscordis-unequaldivisionoftruncusarteriosus-presistenttruncusarteriosus-transpositionofthegreatvessels4)tetralogyofFallot:-unequaldivisionoftruncusarteriosus-fourdefects:/pulmonarystenosis/overridingaorta/membranouspartfailstodevelop/hypertrophyofrightventricle5)patentductusarteriosus