By Team Aakash Byju's

Embryonic Development in Humans: Stages & Key Features

The development and formation of the human embryo are known as Embryonic development.

Embryonic development covers the first eight weeks of development and the embryo is referred to as a fetus at the start of the ninth week.

The stages of embryo development are thoroughly explained in the following points.

It is the union of the female egg and the male sperm, the product formed is a structure called a zygote.


 The embryo is formed from a tiny collection of cells that are constantly dividing inside a complex structure termed the blastocyst shortly after fertilization.

Blastocyst Development

When the blastocyst enters, it implants in the mucus membrane that lines the inside of the uterus.

Blastocyst Implantation

As the blastocyst proceeds through the last stages of implantation into the uterus's inner lining, it develops into an embryo.

Embryo Development

By the twelfth week of fertilization the embryo has advanced to the fetal period, which is the final stage of development.

Fetal Development

Human pregnancy lasts 9 months. After the first month of pregnancy, the embryo’s heart is formed.

By the end of the first trimester, the majority of the major organ systems, the limbs and external genital organs are developed.

During the fifth month, the fetus normally starts to move and hair begins to appear on the head.

By the end of the second trimester, the body is covered with fine hair, eyelids and eyelashes are formed.

The fetus is completely formed and ready for delivery by the 9th month of pregnancy.

Hope now you are clear about the stages and features of embryonic development. Share them with your classmates too.