Question

Explain the terms: (a) implantation (b) placenta

Answer 1

(a) Implantation:

1. It is a stage in human pregnancy which occurs at an early stage after fertilization.
2. After fertilization of the ovum, the embryo travels as a blastocyst toward the uterus and gets embedded in the wall of the uterus. This process is known as implantation.
3. The fertilized egg takes about a week to reach the uterus, the blastocyst adheres to the endometrial lining i.e. the endometrium and eventually moves deeper into the lining.

(b)Placenta:

1. It is a structure that forms the connection between the embryo and uterine wall, it is disc-shaped.
2. It is the main organ for the exchange of nutrients and oxygen between the fetus and the mother. It also removes the waste products from the fetus.
3. It has numerous villi which help in the absorption of nutrients.
4. It also produces hormones like hCG, estrogen and progesterone.