the membrane that forms the wall of the blastocyst in early development; aids implantation in the uterine wall;
"after implantation of the blastocyst in the uterine wall the trophoblast divides into two layers, the chorion and the placenta"
例句
用作名词(n.)
After implantation of the blastocyst in the uterine wall the trophoblast divides into two layers, the chorion and the placenta.在胚泡植入子宫壁后，胚胎滋养层分成两层，即绒毛膜和胎盘。
The direction of blood flow is from the spiral arteries to the microvessels, which suggests that the migration of trophoblast cells is against the stream of blood flow.在此过程中，子宫脉管中滋养层细胞迁移的方向与血流方向相反，是一种特殊的逆血流而上的迁移。
