人體胚胎學

Humanembryology20Preface1.Definition:(定義)Studydevelopmentandmechanismofhumanbodyfromfertilizationtobirth.2.Content(內(nèi)容)(1)Normalhumanbodydevelopmentinuterus.(胚胎發(fā)育)(2)Relationbetweenmotherandembryo.(母子關系)(3)Hereditarymalformationandreproductiveengineering(先天畸形與生殖工程)

受精8周末胚期胎期圍產(chǎn)期

（1-8周）（9-38周）

(26周-生后4周)出生

受精、卵裂、器官系統(tǒng)發(fā)育、胚泡形成、功能建立完善、植入、胚體長大。三胚層形成分化、胎膜胎盤形成器官原基建立有害因素影響可致畸………4、Importanceandmethod(1)Importance

(2)Studymethods21Humanembryogenesisanddevelopmentofearlyperiod1Germcellandfertilization(生殖細胞和受精)(1)Germcell(生殖細胞)

spermatozoon（精子）A.Morphological

maturation(形態(tài)的成熟)

intestisB.SpermatozoaundergoaFunctionalmaturationinprocessofjourneyfromtheseminiferoustubules（生精小管）

totheampullaoftheoviduct（輸卵管）

Ovum(卵子):CharacterA.Oogenesis(卵細胞的發(fā)生）isdiscontinuousandbeginsduringfetallife.B.Thesecondaryoocyteisarrestedatthesecondmeiotic（減數(shù)分裂）metaphase（中期）inovulationC.Coronaradiata（放射冠）andzonapellucida（透明帶）accompaniedoocyteD.Oocytesurvive:1dayCapacityoffertilization:12hours（2）受精fertilization

A.Definition(定義):

Itisaprocessthatthespermatozoon（精子）successfully.penetratestheoocyte（卵母細胞）andformszygote(受精卵）

B.Position(位置):theampullaoftheoviduct(

輸卵管壺腹部)

C.Time(時間):within12hoursafterovulation(排卵)or24hoursafterejaculation(射精)D.條件（1）精卵正常（2）精液質量3-5ml?次，≮400萬個?ml,畸形≯20%,30min內(nèi)液化，活動率≥60%（1小時）。（3）精子獲能,卵子在第二次成熟分裂的中期（4）如期相遇（5）生殖道暢通（6）內(nèi)環(huán)境正常A內(nèi)分泌B抗精子抗體

C精神狀態(tài)Zonareaction(透明帶反應):Corticalgranulesreleaseintotheperivitelline（卵黃周的）spaceandinteractwiththezonapellucida.Italtersthespermreceptormolecules,causingthezonatobecomeimpenetrablebyadditionalspermatozoa.Femaleandmalepronucleiformed(兩性原核形成)Twopronucleimembranesdisappearasbothmaternalandpaternalchromosomesarereplicatedinpreparationforthefirstcleavage.(兩核融合)F.Significanceoffertilization(受精的意義)（1）Formanewlife(形成新個體)（2）Resume2NquantityofDNA(染色體復常)（3）Decidesex(決定性別)TDFandSRY2.Blastocystformed

andimplantation(胚泡形成與植入）(1)Zygotecleavage（卵裂）Within24hoursafterfertilization,thezygoteembarksonaregulatedseriesofmitoticcelldivisionscalledcleavage.Thedivisionsarenotaccompaniedbycellgrowth,sothesubdividethelargezygoteintomanysmallerdaughtercellscalledblastomeres（卵裂球）.

24hours2blastomeres40hours4blstomeres3days6—12cells4days16---32cells(2)Morula（桑葚胚）:bythe32cellstage,theembryohastheappearanceofasmallmulberryandistherefore,calledamorula.12-16細胞時叫做桑葚胚Thesegregationofblastomeresintoembryoblastandtrophoblastprecursorsoccursinthemorula.(3)胚泡（blastocyst）Themoruladevelopsafluid-filledcavityandistransformedintoablastocyst胚端滋養(yǎng)層Polartrophoblast內(nèi)細胞群innercellmass胚泡腔blastocoele滋養(yǎng)層trophoblast(4)植入implantation

A.Definition:B.Time:5-6dayto11-12dayC.condition(條件)1胚泡發(fā)育與子宮內(nèi)膜同步2透明帶準時脫落3宮腔的正常內(nèi)環(huán)境4母體內(nèi)分泌正常E.位置子宮底和體,最多見后壁的中上份F.異常植入

宮外孕前置胎盤4.Clinicalapplications(1)Chromosomalabnormalitiesresultinspontaneousabortionorabnormaldevelopment

Itisestimatedthatonethirdofallconceptions（孕體）innormal,healthywomenabortspontaneously;approximatelyonefourthoftheseoccurbeforepregnancyisdetected.Chromosomalanomaliesappeartocauseabout40to50percentofspontaneousabortionsincasesonwhichtheconceptushasbeenrecoveredandexamined.CauseManychromosomalanomaliesariseduringgametogenesisandcleavageDownsyndromeisanexampleofadisordercausedbyanerrorduringmeiosisormitosisChromosomeanalysiscandeterminetheparentalsourceandthedefectivechromosomeandprovidesabasisfordiagnosisanpossibletreatment(2)Contraceptivetechniquesinterferewithawidevarietyofreproductivemechanisms

受精與節(jié)育和不孕不育Despitethehighrateofspontaneousabortion,humanreproductiveefficiencyisveryhigh.Methods:（1）Barriercontraceptivespreventthespermfromreachingtheegg.(2)Thebirthcontrolpillpreventovulation.(3)injectedorimplantedsourcesofprogestindeliverachronicantiovulatorydose.（(4)NonmedicatedIUDsmayinterferewithconceptionthrougheffectsonbothspermandegg.(5)TheantiprogesteronecompoundRU-486isanabortifacient.(6)sterilizationisusedbyaboutonethirdofamericancouples.(7)newmethodsofcontraceptionareneeded.Infertile(15%-30%inAmerican)Thematurationofhumangametesandearlyembryoscannowbesup