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ID:14658651
大小:8.92 MB
页数:66页
时间:2018-07-29
《embryology of the heart and the great vessels:的心脏和大血管的胚胎学》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、EmbryologyoftheheartandthegreatvesselsDrGerritEngelbrechtDeptofRadiologyUFSESTABLISHMENTOFTHECARDIOGENICFIELDFORMATIONANDPOSITIONOFTHEHEARTTUBEFORMATIONOFTHECARDIACLOOPMOLECULARREGULATIONOFCARDIACDEVELOPMENTDEVELOPMENTOFTHESINUSVENOSUSFORMATIONOFTHECARDIACSEPTAEFORMATIONOFTHECONDUCTINGSYSTE
2、MOFTHEHEARTVASCULARDEVELOPMENTStepsintheembryologyofthevascularsystemESTABLISHMENTOFTHECARDIOGENICFIELDDorsalviewofalatepresomiteembryo(approximately18days)afterremovaloftheamnion.Prospectivemyoblastsandhemangioblastsresideinthesplanchnicmesoderminfrontoftheneuralplateandoneachsideoftheembr
3、yoaftermigratingupfromtheprimitivestreakTransversesectionthroughasimilar-stagedembryotoshowthepositionofthebloodislandsinthesplanchnicmesodermlayer.Withtime,theislandsuniteandformahorseshoe-shapedendothelial-linedtubesurroundedbymyoblasts.ThisregionisknownasthecardiogenicfieldInadditiontoth
4、ecardiogenicregion,otherbloodislandsappearbilaterally,parallelandclosetothemidlineoftheembryonicshield.Theseislandsformapairoflongitudinalvessels,thedorsalaortae.223Cephalocaudalsectionthroughasimilarstagedembryoshowingthepositionofthepericardialcavityandcardiogenicfield.FORMATIONANDPOSITIO
5、NOFTHEHEARTTUBE2processesresponsibleforpositioningoftheheartFoldingoftheembryoinacephalocaudaldirectionSimultanousfoldinglaterallyCephalocaudalfoldingFiguresshowingeffectsoftherapidgrowthofthebrainonpositioningoftheheart.Initiallythecardiogenicareaandthepericardialcavityareinfrontofthebucco
6、pharyngealmembrane.A.18days.B.20days.C.21days.D.22daysLateralfoldingoftheembryoFormationofthecardiacloopBulbuscordisPrimitiveventricleTheprimitiveatriumandsinusvenosusAbnormalitiesofcardiacloopingDextrocardia,inwhichtheheartliesontherightsideofthethoraxinsteadoftheleft,iscausedbecausethehea
7、rtloopstotheleftinsteadoftheright.DextrocardiamaycoincidewithsitusinversusMolecularregulationofcardiacdevelopmentDependentontheactivationoftwotranscriptionfactorsNKX2.5SpecifiescardiogenicfieldSeptationConductionsystemTBX5SeptationDevelopmentofthesinusve
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