What Stages Does Embryo Development Go Through?

The three main steps of embryonic development are the germinal, embryonic, and fetal stages.

The stage of germination (between 0 and 2 weeks) lasts from fertilization to implantation. A blastocyst is created when the fertilized egg (zygote) goes through fast cell division.

Organs and tissues of the embryo develop and grow rapidly during the embryonic stage (2–8 weeks). The heart, brain, and nervous system of the embryo begin to form. Arms, legs, and other body components grow in the embryo as well.

The organs and tissues of the fetus grow and develop during the fetal stage (nine weeks until birth). The fetus starts to move and grow, and its internal organs fully develop.

What Are The Developmental Stages Of The Embryo?


Developmental process of embryo;

Morula Stage:

The stage of development during which the dividing cell mass divides into smaller cells to create the structure known as a morula The name "morula" (Latin for "mulberry") comes from the fact that the morula's cells are densely packed together to create a solid ball that resembles a mulberry. It takes place three to four days after fertilization, when the fertilized egg has divided into 16 to 32 cells. The morula stage plays an important role in development because it signals the beginning of cell differentiation and the formation of the blastocoel. Miscarriage may occur if the morula fails to develop properly.


Blastula Stage:

A blastocyst, which is a hollow ball of cells, was created by the morula. After fertilization, the blastula stage is normally reached in 4-5 days. The cells of the blastula, which is a very dynamic structure, are continually dividing and migrating. At one end of the blastula lies the inner cell mass, which will eventually give rise to the embryo, and at the other end is the trophoblast, which will eventually give rise to the placenta.

Since it initiates gastrulation, the process by which the embryo develops three layers, the blastula stage is a crucial stage in development. When the blastula's cells start to move and arrange themselves into three germ layers, gastrulation starts. The blastocyst also underwent implantation after attachment to the uterine wall. To connect with the mother's blood vessels, it burrows into the endometrium.

Gastrula Stage:

An early multicellular embryo is composed of three germinal cell layers (ectoderm, mesoderm, and endoderm), from which diverse organs arise. The skin, the neurological system, and the sensory organs will develop from the ectoderm. The muscles, bones, and circulatory system will develop from the mesoderm. Lastly, the respiratory system, the gastrointestinal system, and the lining of the bodily cavities will all develop from endoderm.

Neurula Stage:

The ectoderm undergoes a process known as neurulation, which results in the development of the neural tube, and the brain and spinal cord emerge from the neural tube. Normally, the neurula stage begins 7–10 days after fertilization. The development of the neural plate and the notochord are the initial indicators of neurulation. Serious birth abnormalities like spina bifida can result from improper neurula development.


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