Question

What are the major features of embryonic development at various months of pregnancy?

Answer 1

During the first week of pregnancy zygote is formed which then undergoes a series of mitotic division that gives rise to a 16 cell stage called morula.Morula on further division forms blastocyst and its implantation in the uterus occurs.
During the second week , this blastocyst fully gets implanted in the uterus and forms embryo.Now from the 3rd week onwards the development of embryo begins.Initially , the central nervous system is formed then during the next few weeks the heart , eyes and limbs take place , till 9th week the brain is formed that continues to grow till 16th week.
Then during proceeding months , the movement of the baby is observed , and its body is covered with fine hairs , eyelids also appear at this time.By the end of the embryonic stage , all essential external and internal structures have been formed.It is then reffered to as fetus.

Answer 2

During pregnancy, these are the following embryonic development takes place:

- After fertilization when zygote is formed it undergoes mitotic division and converts into morula.

- A morula is a 16 cell stage which later becomes blastocycts.

- During second week, the blastocycts gets implanted in the uterus.

- At the beginning of the third week, development of different system takes place such as the development of central nervous system, limbs formation.

- This process continues and other parts of a body forms such as eye lids, hair etc.

- By the end of the embryonic stage, the formation of all the internal and external structures takes place and the embryo is referred to as fetus.