Events from fertilisation to foetus:
Sperms travel up the vagina and reach the oviduct (fallopian tube), where fertilisation of the egg occurs, forming a zygote. The zygote starts dividing to form a ball of cells called an embryo. The embryo gets implanted in the thickened, blood-rich lining of the uterus and continues developing, with organs forming, to become a foetus.
Role of Placenta:
The placenta is a disc embedded in the uterine wall. It has villi on the embryo's side surrounded by blood spaces on the mother's side, providing a large surface area for transfer of glucose and oxygen from mother to embryo. It also removes waste substances from the embryo into the mother's blood.
Source: Chapter 7, Section 7.3.3(b)
---