Stages Of Embryology

Embryonic Development:Zygote || || Morula || || Blastula || || Gastula ||

Zygote:: This is where the sperm fertilizes the egg. It takes 24-48 hours to process. Also, for furthur understanding the first few mitotic cell divisions are called cleavage.
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Here is a picture of the human Zygote. You can clearly see in this picture the sperm and egg coming together.

This cycle consists of a solid ball of cells, or also known as stem cells.
- - As stated by the National Institute of Health, " Stem Cells have the remarkable potential to develop into many different cell types in the body. Serving as a sort of repair system for the body, they can theoretically divide without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell."
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The next stage Morula is dipicted in this image. It shows the cluster of cells coming together and forming on ball of cells.

This is where the egg attaches to the uterine wall. This process is also called implantation.
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Although this picture isnt in as much detail as the others you can see the cells after forming together attaching to the Trophoblast or the Uterine wall.

This is the formation of three germ layers...
a. Endoderm- Inner most layer of the tissue which becomes organs
b. Mesoderm- This is the middle layer and then becomes muscular tissue
c. Ectoderm- Lastly this is the outer most layet and in the end it becomes the skin
Additionally, the first body cell in the body system is the nervous system and the last is the respiratory system