stages of human embryo

The process of pregnancy, often called the prenatal period, is one of the critical phases for the child’s growth. For pregnant women, monitoring the embryo’s development until it becomes a fetus can give various experiences. One of them is knowing the health of the baby from time to time.

For those of you who don’t know, from the beginning of pregnancy until the delivery process, the baby grows and develops in various phases. Your little one will continue to grow from one period to another, starting from the blastocyst, then developing to form an embryo until it becomes a fetus.

Medically, the pregnancy process that takes an average of 9 months is known to have three development periods. The first period is the stage of zygote formation, followed by the embryo’s development and the phase of fetal growth and development.

As we know, when it is in the form of a fetus, the child’s physical development is almost perfect. You can see the gender, feel the heart rate, or feel kicks from your little one’s activities. This development phase starts from the ninth week and lasts until delivery.

On the other hand, the growth and development of the embryo, which is one of the important phases of the formation of the fetus, is often unnoticed. The term embryo development or embryogenesis is not even widely understood by the public. This stage of embryo development or embryogenesis is essential for the growth and development of the baby’s brain and organs.

So, to know more about embryo development in the prenatal period, we have summarized the stages of embryogenesis from the time the morula is formed until it turns into a fetus.

The Process of Embryo Formation

Before it is a form of a fetus, the initial formation of the embryo comes from the fertilization process. This activity can occur when a sperm cell meets an egg (ovum) in the uterus.

In fertilization, this has entered the early stages of pregnancy. However, women who experience this condition usually are not aware because they do not feel any changes in their bodies.

The following are the three stages of human embryo development during pregnancy.

Read more: The Process of Fertilization and the Occurrence of Pregnancy

Stages of Human Embryo Development

In general, the stage of human embryo development begins in the third week until the eighth week after the fertilization process. Embryo development is a crucial stage in the growth and development of the child’s brain, so special attention is needed so that the child’s growth and development does not experience interference.

1. Morula Phase

The first stage of human embryo development is the morula stage. The beginning of the mention of the morula term itself comes from its small shape and does not have a cavity, like a strawberry.

In this condition, the division of the zygote, which still has a single cell, begins to occur. The division process known as mitosis division later will produce blastomeres or new cells.

The division process occurs in several stages, starting from one cell to two cells, then two cells to become four cells, four cells to become eight cells until the final division of eight cells becomes sixteen cells.

These blastomeres or new cells have a total of 16 cells with solid properties, then all of the solid cells resulting from the mitosis division combine into one to form an embryo sphere known as a morula.

2. Blastula Phase

After the morula phase, the next embryo development and growth process is the blastula phase. Quoting from the Oregon State University journal, Open Educational Resource Unit, the blastula phase will continue until the morula becomes 100 cells. The resulting ball-like shape lump will also create hollows on the inside from the relatively large number of cells. This gap or hollow is known as the blastula.

Medically, the hollow of the blastula formed is known as the blastocoel. This part is then filled with glucose liquid, lactate, pyruvate, and amino acids. In its development, the cell mass of various fluids will turn into the placenta, which acts as a source of nutrition for the embryo.

Meanwhile, the morula will transform into a layer of cell hollows that functions to protect the blastocoel in this phase. This part is called the blastoderm.

Read more: How to Increase Female Fertility Easily That You Should Know

3. Gastrula Phase

After going through the morula and blastula phases, the next phase of embryo development is the gastrula phase. This phase is where the cells produced in the blastula phase experience reshuffle into three embryonic layers, also known as the germ layer.

Based on the explanation from Healthline, the three layers in the gastrula phase each consist of the following components:

  • Ectoderm Layer: This part is the layer that is on the outermost side of the embryo
  • Mesoderm Layer: This layer is in the middle between the ectoderm and the endoderm layer.
  • Endoderm Layer: Can be called as part of the cell nucleus. It is the innermost layer that later will develop into a human fetus.

4. Organogenesis Phase

The organogenesis phase is the last in the embryo development stage. As the name implies, embryos that have entered the organogenesis phase will begin to experience the process of forming organs. The various organs that grow inside the fetus are formed from three germ layers or embryonic layers created in the previous phase (gastrula).

Quoting from Microbe Notes, in detail, each of these germ layers will form the following organs:

  • Ectoderm Layer: As the outermost layer, the ectoderm will form the epidermis, eye organs, inner ear, connective tissue in the head, and nerves.
  • Mesoderm Layer: This layer will form the reproductive organs, excretory system, renal tubules, cardiovascular system, blood cells, the connective tissue of the body, and various types of muscles.
  • Endoderm Layer: The organs formed from this layer are the liver, pancreatic cells, thyroid gland, digestive system, lungs, and reproductive organs.

That’s a complete explanation regarding embryo development or embryogenesis that you need to know. Every period in the pregnancy process is very important to be paid attention to. Although the baby-to-be is medically not yet considered a fetus, at least until the 9th week after the fertilization process occurs.

The embryo development phase is when the baby-to-be forms the basic framework or foundation. For the growth and development to be more optimal, mothers must pay attention to nutritional intake lifestyle and routinely carry out examinations from the beginning of pregnancy.

Besides, as the baby grows, the mother-to-be can also take care of herself, follow the doctor’s advice, and grow a relationship to be more connected to the fruit of life developing in your body. Hopefully, the information above can be helpful!