This process can be mediated through trophoblastic cell which originated in trophectoderm ; the blastocyst cavity surrounded it and the inner cell mass 1 w_199 .

这个过程受 滋养层 细胞的介导，滋养层细胞是 一群 特化 的 细胞，起源于 滋养 外 胚层，它包围着囊胚腔以及内细胞团1w_233。

Genes regulating development and differentiation participate in the embryo development and differentiation of inner cell mass and trophectoderm which controls the transition from undifferentiation to differentiation stage .

调节发育和分化的基因参与胚胎的发育和内细胞团、 滋养 外 胚层 细胞的分化，调节 胚胎由未分化状态向分化状态过渡。

The trophectoderm maintains the pressure by pumping the fluid into the cavity .

滋养层通过向腔内泵入液体来维持这种压力。