A chorionic villus is a minute vascular projection on the fetal chorion. 绒膜绒毛是胎儿绒毛膜上的一种微小的血管凸出物。
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。