【醫(yī)學(xué)生物】組織胚胎學(xué)課件9

組織胚胎學(xué)課件

中國醫(yī)科大學(xué)基礎(chǔ)醫(yī)學(xué)院組胚—英文教學(xué)組1業(yè)精于勤荒于嬉行成于思?xì)в陔S→【醫(yī)學(xué)生物PPT，歡迎收藏分享】豆丁網(wǎng)友組織胚胎學(xué)課件

中國醫(yī)科大學(xué)1業(yè)精于勤荒于嬉行成于思?xì)UMANEMBRYOLOGY

DepartmentofHistologyandEmbryologyChinaMedicalUniversityHUMANChapter3

FirstWeekofDevelopment:OvulationtoImplantation

Chapter3OvarianCycleAtpuberty,thefemalebeginstoundergoregularmonthlycycles.ThesesexualcyclesarecontrolledbytheHPG(Hypothalamus-Pituitary-Gonad)axis.GnRH,Gonadotropin,follicle-stimulatinghormone(FSH)luteinizinghormone(LH)/ICSH

OvarianCycleAtpuberty,theAtthebeginningofeachovariancycle,15to20primary(preantral)folliclesarestimulatedtogrowundertheinfluenceofFSH.Undernormalconditions,onlyoneofthesefolliclesreachesfullmaturity,andonlyoneoocyteisdischarged;theothersdegenerateandbecomeatretic.Whenafolliclebecomesatretic,theoocyteandsurroundingfollicularcellsdegenerateandarereplacedbyconnectivetissue,formingtheinterstitialgland(corpusatreticum).Atthebeginningofeachovar

Granulosaandthecalcellsproduceestrogensthat(a)causetheuterineendometriumtoenterthefollicularorproliferativephase;(b)causethinningofthecervicalmucustoallowpassageofsperm;(c)stimulatethepituitaryglandtosecreteLH.GranulosaandthecalcellsprAtmid-cycle,thereisanLHsurgethat(a)causesoocytestocompletemeiosisIandinitiatemeiosisII;(b)stimulatesproductionofprogesteronebyfollicularstromalcells(luteinization);(c)causesfollicularruptureandovulation.Atmid-cycle,thereisanLHsOvulationOvulationTheprocessthatthematurefolliclerupturesandthesecondaryoocyte,zonapellucida,coronaradiataandfollicularfluidarereleasedfromtheovaryiscalled～.Time:ovulationtakesplaceataboutthemiddleofthecycle.OvulationTheprocessthatthematurefo【醫(yī)學(xué)生物】組織胚胎學(xué)課件9ThefateofthesecondaryoocyteafterovulationDegenerationundergoesifnofertilizationoccurs.Iffertilizationhappens，thesecondmeiosisisfinished,andtheovumforms.ThefateofthesecondaryoocyFATE1FATE2FATE1FATE2Afterovulation,granulosacellsremaininginthewalloftherupturedfollicle,togetherwithcellsfromthethecainterna,arevascularizedbysurroundingvessels.UndertheinfluenceofLH,thesecellsdevelopayellowishpigmentandchangeintolutealcells,

whichformthecorpusluteumCorpusLuteumAfterovulation,granulosacelGRANULOSALUTEINCELLSTHECALUTEINCELLSGRANULOSALUTEINCELLSTHECALU

Cellsofcorpusluteum

GranulosaluteinC：progesteroneandrelaxinThecaluteinC：estrogenProgesterone,togetherwithestrogen,causestheuterinemucosatoentertheprogestational

orsecretorystage

inpreparationforimplantationoftheembryo.CellsofcorpusluteumProgestFateofcorpusluteumCorpusluteumofmenstruation

→corpusalbicansCorpusluteumofpregnancy→corpusalbicansFateofcorpusluteumCorpusalbicansCorpusalbicansRelationoffimbriaeandovary.Fimbriaecollecttheoocyteandsweepitintotheuterinetube.RelationoffimbriaeandovaryFertilization---Fertilizationistheprocessinwhichthemaleandfemalegametes(spermandovum)unitetogiverisetoazygote.---place:intheampullaoftheuterinetubeFertilization---FertilizationConditionsoffertilization:1)

maturationofoocyte2)maturationofspermatozoa:2-3weeksintheductusepididymisacquiresomemotilityConditionsoffertilization:decapacitationfactor:existinepididymis,toinhibitthereleaseofacrosomeenzymes

capacitationfactor:secretedbyepi.cellsofoviduct,capacityofreleasingacrosomeenzymescapacitationofspermatozoadecapacitationfactor:existi

3)qualityandquantityofspermatozoa:normal:3-4ml,100,000,000/ml,abnormal:<1.5ml;or<10,000,000/ml;abnormalsperm>30%;mobility<70%4)

meetingofspermandovumsperm:<4daysovum:<2days3)qualityandquantityofspeprocessesoffertilization:

1)

acrosomereaction:A.hyaluronicacidase:dissolvecoronaradiataB.interactwithZP3(receptorglycoprotein,existinzonapellucida)molecules,releaseacrosin:dissolvezonapellucidathensomespermatozoaenterperivitellinespaceprocessesoffertilization:

2)onlyonespermatozoonfusewithmembraneoftheovum:nucleusentercytoplasmoftheovum

corticalreaction:corticalgranules(locatedincytoplasmofovum)arereleasedintoperivitellinespace,andcausezonareaction:changeofZP3moleculesinzonapellucide2)onlyonespermatozoonfu3)formationofzygote(fertilizedovum)A.secondarymeiosiscomplete:formsecondpolarbodyB.malepronucleusfusewithfemalepronucleustorestore2Nchromosomes3)formationofzygote(fertil【醫(yī)學(xué)生物】組織胚胎學(xué)課件9significanceoffertilization:1)anewlifebegin(initiationofcleavage)2)restorationofthediploidnumberofchromosomes3)determinationofthesexofthenewindividual:ovum(22+X)+X-bearingspermatozoon=girlovum(22+X)+Y-bearingspermatozoon=boysignificanceoffertilization:Blastocystformation

and

implantation

Blastocystformation

and

imp

2-cellstage8-cellstage4-cellstage

morulaEarlyblastocystLateblastocyst2-cellstage8-cellsta1)cleavageandblastocystformation①cleavage:mitosisofthezygote---blastomere:cellsfromcleavage30h:2cells40h:4cells72h:12-16cells–morulaformation1)cleavageandblastocystfor②formationofblastocyst:by5thday,blastomerereachto107,smallspaceappearbetweenthemblastocoele:filledwithliquidtrophoblastinnercellmass(embryoblast

)polartrophoblastinnercellmassblastocoeletrophoblastZonapellucidaPolartrophoblastEarlyblastocystlateblastocyst②formationofblastocyst:inne【醫(yī)學(xué)生物】組織胚胎學(xué)課件9

2)

Implantationdefinition:theprocessinwhichtheblastocystisembeddedinendometriumoftheuterustime:beginonthe5th–6thday;finishonthe11th–12thdayplace:fundusandbodyofuterus2)

Implantation

process:zonapellucidedisappear→polartrophoblasttouchtheendometrium→secreteproteolytase→dissolvetheendothelium→embeddedintoendometrium→coagulationplugsealthespaceprocess:zonapellucidedisap*trophoblastbecomeintotwolayerswhenblastocystisembeddingintoendometriumsyncytiotrophoblastcytotrophoblastendometriumColumnarepithelium*trophoblastbecomeintotwoA7.5-dayhumanblastocyst,partiallyembeddedintheendometrialstroma.Thetrophoblastconsistsofaninnerlayerwithmononuclearcells,thecytotrophoblast,andanouterlayerwithoutdistinctcellboundaries,thesyncytiotrophoblast.Theembryoblastisformedbytheectodermandendoderm.Theamnioticcavityappearsasasmallcleft.ectodermendodermA7.5-dayhumanblastocyst,padecidualresponseofendometriumstromacell→predecidualcell→decidualcell(cellbecomelargerandrichinglycogenandlipiddroplets)decidualresponseofendometriendometrium→decidua:deciduabasalis