胚泡腔被卵黄囊取代，三个2子宫腺羊膜腔amnioticcavityCeCCCPO小血管合体滋养层上胚层epiblast07010/0ODn子宫细胞滋养层上皮下胚层卵黄囊yolksachypoblast
子宫腺 小血管 合体滋养层 上胚层 epiblast 细胞滋养层 胚泡腔被卵黄囊取代，三个2 子宫 上皮 下胚层 hypoblast 羊膜腔amniotic cavity 卵黄囊yolk sac
二胚层胚盘细胞滋养层羊膜蜕膜血管二胚层胚盘soo0KEY00000子宫上皮卵黄囊胚外体腔
二胚层胚盘 蜕膜血管 卵黄囊 胚外体腔 子宫上皮 二胚层胚盘 羊膜 细胞滋养层
胚外中胚层exocoelomicmesoderm合体滋养层滋养层陷窝羊膜细胞滋养层23650600000a10coo胚外中胚层封闭栓卵黄囊
滋养层陷窝 合体滋养层 羊膜 细胞滋养层 胚外中胚层 封闭栓 卵黄囊 胚外中胚层exocoelomic mesoderm
胚外体腔出现母体腺体母体血管蜕膜血管滋养层腔隙?绒毛间陷羊膜腔胚外体腔胚盘胚外内胚层000000000ooooKEY细胞滋养层
胚外内胚层 胚盘 胚外体腔 羊膜腔 母体腺体 母体血管 蜕膜血管 细胞滋养层 胚外体腔出现 滋 养 层 腔 隙 绒 毛 间 隙
胚外体腔extraembryoniccoelom体蒂connecting（body）stalk胚外体腔extraembryoniccoelomTtoroblasticAaternalsinusoid:ProchordalPrimarsTrophoblasticlacunaenadclatoMaternalsinusoidConnectingstalkAmnioticcavityEndodermcellsBecondaryvolksaoExtra-embryonicExtra-embryonicsomatopleuriccoelomnesoderm(chorionic plate)xtra-embryonicExtra-embryonic(chorionic cavity!egsplanchnopleuricmesodermeipoExtra-embryonicExocoelomiccavityomiccyssomatopleuricmesodermExocoelomic(primitiveyolksac)membrane
胚外体腔 extraembryonic coelom 体蒂connecting (body) stalk 胚外体腔 extraembryonic coelom