人胚胎早期发生课件

Generalembryology(I)OBJECTIVES

fetalperiod〔胎儿期〕:after9weeksFertilization〔受精〕Definition:theprocessbywhichthemaleandfemalegametes(spermandovum)unitetogiverisetozygotesite:intheampullaryregion〔壶腹部〕oftheoviductconditions:1)

maturationofoocyte2)

maturationofspermatozoa

3)

capacitation〔获能〕andacrosomereaction〔顶体反响〕ofspermatozoacapacitationfactor:secretedbyepi.cellsofoviduct,capacityofreleasingacrosomeenzymes4)

qualityandquantityofspermatozoa:2-6ml,100,000,000/ml,<1.5ml;or<10,000,000;abnormalsperm>30%;orcapacityformobile<70%5)

meetingofspermandovumwithin24hrsProcessesoffertilization:PhaseIPenetrationofthecoronaradiata〔放射冠〕,acrosomalreleasePhaseIIPenetrationofthezonapellucide〔透明带〕ZPwithreceptors–zonapellucidaspongy–thereleaseoflocalenzymesPhaseIIIEntrance,formationofzygoteEntry–responseCorticalorzonareactions-Compaction-impermeabletomorespermOocytefinishes2ndmeioticdivisionMetabolicactivation

oftheeggResultsoffertilizationDiploidGeneticsexCleavageinnercellmassblastocoeletrophoblasts〔滋养层〕〔内细胞群〕Puberty–menstruation(28days)HormonalregulationGnRHFSHLHGranulosa/thecacellsEstrogensProgesteronesTheendometriumoftheuterusisinthesecretoryphaseUterusatTimeofImplantationImplantation〔植入〕-PassagethroughtheuterinetubeDay5–Day11UterusOrientationofimplantationLocation-antorpost,fundusTrophoblastsoverlyingtheembryoblastpoleattachtotheendometriumandbegintoinvade.Processes

zonapellucidedisappear→polartrophoblasttouchtheendometrium→secreteenzymes→dissolvetheendometrium→embeddedintoendometrium→coagulationplugsealthespaceImplantationsiteNormal:antorpostwalloftheuterus,fundusAbnormal:Internalosofthecervix(placentaprevia)OvarianAbdominalTubalEctopicpregnancyendometrium→decidua:-deciduabasalis〔底蜕膜〕-deciduacapsularis〔包蜕膜〕-deciduaparietalis〔壁蜕膜〕conditions:-endometriumisinsecretoryphase-morulareachthecavityofuterusontime-zonapellucidedisappearsintimeIn

vitrofertilisationPreimplantationGeneticDiagnosisImplantation-sinksdeeperTheoutercelllayerTrophoblastsCytotrophoblasts

细胞滋养层Syncytiotrophoblasts

合体滋养层Innercellmass(embryoblast)Fluidcollection–amnionEpiblasts&hypoblastsWeektwo–Day9-12ImplantationCoveredtheendometrium-fibrinplugComplete–slightbulgeTrophoblastsVacuoleswithinsyncytiotrophoblasts-fuseandformlacunarnetworksUteroplacentalcircExtra-EmbryonicMesodermBtwntroph&cavitySomatic/splanchnicWeek2–Day13-14TrophoblastsPrimaryvilliYolksacPrimarytosecondaryChorionicplateConnectingstalkTheBilaminarEmbryoEndoftheWeekofTwos2majorcellmassesTrophoblasts