Question

Explain the formation of placenta after the implantation in a human female.

Answer 1

The placenta, which supplies nutrition to the developing foetus, is a unique characteristic of placental mammals. The placenta, which serves as a structural and functional link between the developing embryo (foetus) and the mother’s body, develops between the chorionic villi and uterine tissue after around 12 weeks of pregnancy. Upon the implantation of a blastocyst in the mother’s endometrium, the placenta starts to grow. Two different cell types make up the blastocyst: the inner cell mass and the outer trophoblast cells. The trophoblast cells grow to create the placenta, while the inner cell mass gives rise to the foetus and the protective barrier around it. Between 18 and 20 weeks of pregnancy, the placenta is developed, and it keeps expanding. A chorio-allantoic placenta is one that develops from the chorion and allantois in the human placenta. The placenta protects the foetus from the typical immune reaction that releases antibodies, even though the mother’s body may perceive it as a foreign body.

Answer 2

1. After implantation, the trophoblast develops finger-like structures called chorionic villi, which are surrounded by uterine tissue and maternal blood.
2. The chorionic villi interlock with the uterine tissue to form the placenta.
3. The placenta acts as a structural and functional link between the embryo (foetus) and the mother’s body.
4.  It is connected to the embryo through the umbilical cord, which carries substances to and from the developing embryo.