Question

How does the placenta form during pregnancy?

Answer 1

Placenta:

1. The placenta is a connection between the mother and the developing embryo in the uterus.
2. It provides nutrition and oxygen to the embryo and removes waste from embryonic blood.
3. It is found in all viviparous animals.
4. Different animals have different types of placenta. Human embryo have the chorioallantoic type of placenta.

Placentation in humans:

1. The development of the placenta is called placentation. In humans, placental formation starts in the third week of pregnancy.
2. At the stage of the blastocyst, the embryo has two different cell types trophoblast cells and inner cell mass.
3. The inner cell mass forms the foetus and the trophoblast forms the placenta.
4. From trophoblast, some processes develop that connect with the uterine wall.
5. From the placenta, the umbilical cord is developed that is also connected to the foetus.