Every process of embryonic development

What are the various processes of embryonic development?

The first week of life

After many times of division, the fertilized egg forms a cell mass, grows up gradually and begins to differentiate at the same time. One part becomes a fetus, and the other part becomes an accessory organ that supplies nutrition and protects the fetus. This is the first week of life.

Spine formation

In the third week, the baby grows very rapidly and the spine forms. Brain tissue, spinal cord, nervous system and eyes all have certain embryonic shapes, and at the other end of the spine is a small tail. At this time, there are blood vessels, and the heart has not yet formed, but the part that produces the heart has a heartbeat.

The beating of the heart

In the sixth week, the beating embryo grows rapidly, and the heart begins to divide into ventricles, beating regularly and starting to supply blood. Fetal cells are still dividing rapidly. The rudiments of kidney and heart have developed, and neural tubes have begun to connect the brain and spinal cord.

The birth of a fetus

At the 40th week, most of the fetuses will be born in this week, and only about 5% of the babies can give birth at the expected date accurately. It is normal to advance or postpone for two weeks. At this time, due to the shedding of body surface villi and fetal fat and the production of other secretions, fetal amniotic fluid began to change from clear to turbid and milky white. From then on, the placental function gradually degenerated until the fetus was delivered.