组织学与胚胎学 胚胎学2.ppt

Germ disc form and differentiate胚层的形成和分化
主讲人: 苏衍萍
1、Development of the bilaminar germ disc
(二胚层的形成,2w):
(1)二胚层胚盘
(bilaminar germ disc)。
上胚层(epiblast)
下胚层(hypoblast)


羊膜腔(amniotic cavity),
卵黄囊(yolk sac)。
羊膜腔
上胚层
下胚层
卵黄囊
体蒂
(body stalk)
(2)The amniotic cavity develops within the epiblast
上胚层
下胚层
(3)The formation of the yolk sac(卵黄囊形成)
初级卵黄囊
胚外中胚层的网状组织
On days 10 to 11, an acellular extraembryonic reticulum form between Heuser’s membrane and the cytotrophoblast.
下胚层形成次级卵黄囊
(4)The hypoblast gives rise to the extraembryonic endoderm that lines the primary yolk sac
(5)The chorionic cavity is produced in conjunction with the development of the extraembryonic mesoderm
(6) The definitive yolk sac is formed by a new wave of cells that migrate from the hypoblast and displace heuser’s membrane
2、三胚层的形成(第3周)
(1)The primitive streak appears at the beginning of the third week(原条的出现,3w)原条 primitive streak
原结 primitive node
原凹 primitive pit
原沟 primitive groove
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