Embryonic development | stages of human embryonic development | pharmacyteach.com

 

Embryonic development | stages of embryonic development

 

Introduction

You may have heard that human embryos grow and develop quickly in the early stages of pregnancy, but did you know that the process is actually quite slow?

Embryos go through many changes as they grow and develop, and each stage is crucial for their overall development. In this article, we'll take a closer look at each stage of human embryonic development and what happens during that time.

As you probably know, human embryos grow and develop over time. Here's a look at how that process works.

The first step is fertilization when the sperm and egg come together. At this point, the embryo is just a single cell.

Then, the embryo starts to divide and grow. This happens very quickly, and by the fifth day, the embryo has about 100 cells.

Around day seven, the embryo starts to form into three layers: the ectoderm (the outer layer), the mesoderm (the middle layer), and the endoderm (the inner layer).

The ectoderm will become the skin, hair, nails, and central nervous system. The mesoderm will become muscles, bones, blood vessels, and cartilage. And the endoderm will become the liver, pancreas, and lungs.

 

 Embryonic development 

   Development is the duration of the period in which rapid growth in size, mass, and other differentiation of organs system occur during the embryonic period.

During the developmental period, various organism systems formed such as the brain, respiratory and digestive systems, etc.

    The formation of a constitution That is necessary for adults is Known as embryonic development. it is starting a series of mitotic divisions of 2 cell stages ( zygote) which lead to a multicellular stage Called embryo finally an adult the body is formed. 

 

The Stages of Human Embryonic Development

As your baby grows inside you, you may be curious about what's happening developmentally. Here's a basic overview of the different stages of embryonic development.

First trimester: This is the earliest stage, and it lasts from weeks 1 to 12. During this time, the embryo is just a small ball of cells.

Second trimester: This stage lasts from weeks 13 to 27. The embryo is now about the size of a grape and has started to form features like arms and legs.

Third trimester: This stage lasts from weeks 28 to 40. The embryo is now fully formed and is ready for delivery!

 

The embryonic development process is completed in the following stages. 

1 . Cleavage:  in this stage zygote undergoes to series of mitotic divisions.

2 . Gastrulation:  in these stages, three germ layers become well-differentiated which include ectoderm, mesoderm, and endoderm.

 

3 . Organogenesis:-  this is the last stage in which the organ and the system of the organism are formed.

 

4. Growth:  in this stage organism is increased in size and mass.

cleavage:-

    Once fertilization occurred, mitotic division begins in the zygote the process known as cleavage. 

 

What is Morula and Blastula?

  

Two identical cell formation results of first division as known as Blastomere. 

In this stage DNA and mitotic division repeatedly occurred. 

After each division cells get smaller finally a solid mass of small cells, morula is formed. But size is the same as a zygote. 

 

As cleavage continues, cells start to apart so that in the center of cell mass some spaces are appeared as a result forming a fluid cavity known as blastocoel. 

 

This fluid-filled cavity ( embryo) is developed as a result of a cleavage stage called " Blastula" this embryonic stage in mammals is called a blastocyst 

 

The Blastocyst is a fluid-filled hollow sphere consisting of two types of cells,

 

1) Trophoblast is a layer of the large flattened cell.

2)  Inner cell mass, a cluster of rounded calls find on one side,

   the Amount and concentration of yolk in the egg will affect the patterns of cleavage.

Egg yolk serves as food for developing embryos because it is a source of protein, phospholipids, and fats. 

 

Each animal groups have a different distribution of yolk.

 

Most invertebrates and other simple chordates have uniformly distributed egg yolk throughout the cytoplasm.

 

Many vertebrates have a large concentration of yolk present at one side of the cell known as a vegetal pole.

The opposite side is called the animal pole.

 

So, the cleavage pattern depends upon the yolk concentration and its distribution in the egg 

 

 

Important Milestones in Human Embryonic Development

So what are some of the most important milestones in human embryonic development? Here's a quick rundown:

1. The fertilized egg begins to divide, and this process is called mitosis.

2. The cells start to specialize, and this is when the embryo starts to look like a little person.

3. The neural tube starts to form, and this is when the brain and spinal cord begin to grow.

4. The heart starts beating, and the embryo begins to move around.

5. The baby starts to look more human, with features like eyes and ears.

6. The baby starts to grow hair and nails.

7. The baby starts to suck its thumb and yawn.

8. Birth!

How Environmental Factors Can Affect Human Embryonic Development

You probably know that the environment can have a big impact on human development, especially in the early stages. But did you know that environmental factors can even affect embryos while they're still in the womb?

There's a lot of research that still needs to be done in this area, but scientists have already discovered a few ways that the environment can influence embryonic development. For example, exposure to toxic chemicals can cause birth defects, and nutritional deficiencies can lead to developmental problems.

So it's important to be mindful of the things you come into contact with during your pregnancy. Make sure you're eating a healthy diet, and try to avoid anything that might be harmful to your baby. You want to give them the best start possible in life!

Conclusion

In conclusion, the development of human embryos is an intricate and complex process that takes place over a period of nine weeks. During this time, the embryo goes through a number of changes as it grows and matures.

Although there is still much to learn about embryonic development, scientists have made some amazing discoveries in recent years. We now know more than ever about how embryos grow and what happens during the early stages of pregnancy.

Thanks for reading! We hope you found this article informative.

As human embryos grow and develop over time, they go through various stages of development. Each stage is unique and involves different processes and changes.

It's important to know about the different stages of embryonic development so that you can better understand how your own embryo is growing and developing.