What are the blastula and gastrula?

La blastula and gastrula They are two crucial stages in the embryonic development of many animals. During embryogenesis, the fertilized egg undergoes a series of changes that transform it into a complex and developed embryo.

Blastulation

La blastula It is the early stage of embryonic development, where the fertilized egg divides repeatedly into smaller cells and forms a spherical structure composed of cell layers. During the formation of the blastula, the cells organize in only one outer layer called trophoblast or ectoderm, and an inner mass of cells called blastocoele.

Different types of blastulas

• In mammals, the blastula is called blastula.
• In amphibians, the blastula is called blastomere.
• In fish, the blastula is called hollow blastula.

Gastrulation

La gastrulation It is the next stage of embryonic development after blastulation, in which the cell mass of the blastula organizes to form three germ layers – the endoderm, mesoderm and ectoderm. During gastrulation, the blastula cells invaginate and move into the cell ball to form a double spiral-shaped structure called gastrula.

Importance of gastrulation

The formation of the three germ layers during gastrulation is a crucial step in the formation of embryonic tissues and organs. The mesoderm becomes muscles and skeleton, the endoderm becomes the digestive tract, associated glands, lung and bladder, while the ectoderm becomes the skin, brain, spinal cord, nerves and glands. mammary

Conclusion

In summary, The blastula and gastrula are two key stages of embryonic development that occur early in embryogenesis. The blastula is the first stage, where the cells of the fertilized egg divide and organize into a spherical structure with a single outer layer and an inner mass of cells, while gastrulation is the next stage, where the blastula cells become They organize to form three germ layers that will give rise to embryonic tissues and organs. Simply put, blastula is the result of early cell division, while gastrulation is the stage in which the formation of tissues and organs begins.

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