组织学与胚胎学胚胎学

组织学与胚胎学胚胎学体蒂(bodystalk)(2)Theamnioticcavitydevelopswithintheepiblast上胚层下胚层(3)Theformationoftheyolksac(卵黄囊形成)初级卵黄囊胚外中胚层得网状组织Ondays10to11,anacellularextraembryonicreticulumformbetweenHeuser’smembraneandthecytotrophoblast、下胚层形成次级卵黄囊(4)Thehypoblastgivesrisetotheextraembryonicendodermthatlinestheprimaryyolksac(5)Thechorioniccavityisproducedinconjunctionwiththedevelopmentoftheextraembryonicmesoderm(6)Thedefinitiveyolksacisformedbyanewwaveofcellsthatmigratefromthehypoblastanddisplaceheuser’smembrane2、三胚层得形成(第3周)(1)Theprimitivestreakappearsatthebeginningofthethirdweek(原条得出现,3w)

原条

primitivestreak原结primitivenode

原凹primitivepit原沟primitivegroove两胚层胚盘背面观原条外胚层羊膜切缘口咽膜内胚层口咽膜胚盘脊索突原结原条泄殖腔膜中胚层Significance:

Theappearanceoftheprimitivestreakestablishesthelongitudinalaxisandthusthebilateralsymmetryofthefutureadultanddecideembryoorientation

1、确定了中轴

2、确定头尾方向

3、就是胚体得组织中心(2)Thedefinitiveendoderm(内胚层)andintraembryonicmesoderm(胚内中胚层)formthroughtheprimitivestreak12大家应该也有点累了，稍作休息大家有疑问的，可以询问和交流theectoderm外胚层themesoderm中胚层definitiveendoderm内胚层theepiblast上胚层Theprimitivestreakretreatsanddisappears,andthecaudaleminencegivesrisetocaudalstructuresofthebody、(15-26day)ThemechanicsofgastrulationarenotwellunderstoodThefateofgastrulationepiblastcellscanbepredictedfromtheirsiteoforigin、Studymethod:Celltracingandcelllineage(细胞系)studies(3)Thenotochord(脊索)isproducedbycellsthatingressthroughtheprimitivenodePrimitivepot(原结)TheNotochordalprocess(脊索突)thenotochordalplate(脊索板)thenotochord(脊索)意义:决定胚体中轴诱导外胚层形成神经板椎间盘中髓核。Theultimatefateofthenotochordisdebated、Mesodermisexcludedfromthebuccopharyngealandcloacalmembrances、小结:胚胎发育:第一周:植入第二周:二胚层第三周:三胚层第四周:圆柱体四、三胚层得分化1、外胚层得分化(1)神经管形成:

neuralplate神经板

neuralgroove神经沟

neuralfold神经褶

neuraltube神经管脑、脊髓前神经孔未闭无脑儿后神经孔未闭脊髓裂脊柱裂

Meningohydroencephalocele(脑积水脑膜脑突出)Thisanomalymayformthroughdefectiveossificationoftheoccipitalboneandprobablyisnotaconsequenceofdefectiveclosureoftheneuraltube、Headlessmice、Thedevelopmentandmaintenanceofthe“headorganizingcenter”requirestheexpressionofthehomeoboxgeneLim-1、KnockoutofLim-1resultsinheadlessmice、Fig4-12小结:神经系统、脑垂体、松果体、皮肤:表皮、附属结构凹陷上皮:口、鼻、肛门、外耳道、膜迷路、角膜上皮、视网膜、晶状体肾上腺髓质、腮腺上皮(2)神经嵴周围神经系统

肾上腺髓质

分化外胚层分化(3)表面外胚层:皮肤表皮及其附属器2、mesodermdifferentiate(中胚层得分化):(1)paraxialmesoderm(轴旁中胚层)——(somites)体节,第5周全部形成,共42-44对,分化为真皮,大部分中轴骨与骨骼肌。(2)intermediatemesoderm(间介中胚层)——位于体节外侧

,泌尿生殖系统发生得原基。(3)lateralplatemesoderm(侧中胚层)——分两层A:Parietalmesoderm(体壁中胚层):分化为体壁得肌肉、结缔组织、浆膜壁层。B:Ventralmesoderm(脏壁中胚层):分化为内脏平滑肌、结缔组织与浆膜脏层。胚内体腔:形成体腔。体节21天3、Endodermdifferentiate(内胚层得分化):随胚体得卷曲,内胚层