Embryology is ... The history of embryology

Science biology includes a lot of different sections, smaller, but very important, specializing in some specific problems of disciplines. This makes it so vast and globally significant for humanity that it is simply impossible to overestimate its influence.

One of such important sciences was embryology. This is quite an old discipline, the notion of which and the history of formation we will consider in this article.

The concept of the science of embryology

Embryology is not just a biological discipline. This is a whole science that studies the formation, development and formation of embryos of living beings from the moment of appearance of sexual cells and their fusion to the birth of a new organism.

All these processes are very important, their correct and normal course is vital . Therefore, the goal that this science sets itself is to study all questions and mechanisms related to embryos, their life, education and development.

Based on the goal, the tasks of embryology are the following items.

1. Consider the processes of cell division.
2. Identify the patterns of formation in embryos of primary petals and body cavities.
3. Track the options for shaping the axes of symmetry of the body of the future organism.
4. Features of the formation of the cavities of the coelom and their derivatives.
5. Formation of membranes around the embryo.
6. The formation of a whole system of organs, which ultimately identifies this or that organism.

Thus, it becomes clear what embryology is. This is a narrowly specialized science on the intrauterine development of embryos from the time of their formation and until they come to light. And also the study of issues related to the processes of gametogenesis, that is, the formation of sex cells.

Etymology of the word

The meaning of the word "embryology" is quite simple. After all, in Latin, the word "embryo" is pronounced as embryon, and the second part of the word logos is the doctrine. So it turns out that the title of science reflects all of its profound meaning, the subject of study is briefly expressed.

In all modern explanatory dictionaries, the meaning of the word "embryology" is similar. It is almost the same as in the translation from Latin. Add something new to the complex. What is embryology? In all sources, the answer is one - the science of pre-embryonic and embryonic development of animals, humans and plants.

History of the development of science

The history of embryology takes its origin from antiquity. One of the first to study in this area was Aristotle. His observations were to study the formation of the embryo of a chicken egg. This was the beginning of the development of the science in question.

Later, by the XVI-XVII centuries, scientists who were representatives of this discipline, divided into two camps on theoretical views on the formation of embryos, and in general the origin of new organisms.

So, there were:

• Theory of preformism;
• Epigenesis.

The essence of the first is as follows: all the structures of the future organism do not develop over time, but already exist in a very reduced form either in the ovum (ovist) or in the sperm (animalculists). And with the course of life and development of the embryo, they simply increase in size due to the nutrients they receive.

Such views were, of course, erroneous. However, they existed almost until the middle of the XIX century. Adherents of these views among scientists of different time periods were:

• Marcelo Malpighi.
• J. Swarmerdam.
• S. Bonnet.
• A.Galler.
• A. Levenguk.
• I. N. Liberkun and others.

The second theory in the history of the development of embryology, which was also adhered to by a considerable number of bright heads of different time, is called epigenesis. Supporters of her believed that the body begins to develop only after getting the sex cells in each other. At the same time, there is nothing ready in the embryo that forms. Structures, future organs are formed gradually, from internal tissues.

Representatives who adhered to these views were:

• W. Harvey.
• G. Leibniz.
• Friedrich Wolff.
• Carl Baer and others.

In the confrontation of these two camps, numerous data of embryology were accumulated, because scientists constantly carried out research, experiments, and collected theoretical material.

Starting from the middle of the XIX century, according to the views of the preformists, crushing blows were made thanks to the following discoveries.

1. Law on the similarity of the embryos of Carl Baer. In it, he says that on what the earlier stage is the embryo, the more it resembles similar structures in other representatives of wildlife.
2. Wolff described the foundations of the formation in the chicken embryo , proving their gradual formation.
3. The work of Charles Darwin, in which he describes his views on the problem of the origin of species.

The result was the gradual formation of science as we see it today. The following scientists of the XIX-XX century made a great contribution to the development of discipline:

• Kovalevsky.
• Mechnikov.
• Haeckel.
• Wilhelm Roux and others.

Classification

The main sections of the science under consideration can be designated by the following points.

1. Comparative embryology.
2. Experimental.
3. The total.
4. Ecological.

According to the type of organisms studied, embryology is also subdivided into:

• Vegetable;
• Animal;
• Rights.

Each section has its own goals, objectives and objects of research, which have great theoretical and practical importance in understanding the mechanisms of life. Embryology of animals is a very important branch of science in agriculture, animal husbandry.

The structure of general embryology

General embryology is engaged in research and comparative analysis of the embryos of all organisms at different evolutionary stages of the planet's development. As a result, a lot of factual material proves the unity of the origin of all life on our planet.

In the field of research of this discipline is the study of the processes of gametogenesis. Data embryology is important in the health of the future generation, so this science is given special attention.

Characteristics of comparative embryology

The main method of comparing data in this discipline is analysis. Comparative embryology deals with the study of embryos of animals, plants or humans in order to determine the similarity or origins of development.

The founder of it was Karl Baer, who discovered the human ovum and formulated the first law on embryos. A great contribution to the development of knowledge of the discipline was made by Haeckel. His biogenetic law has been universal for a long time. Comparative embryology accumulated evidence supporting this feature.

In simpler terms, the essence boils down to the following: every embryo passes through many stages during its development. All of them together are a repetition of the general course of evolution that all organisms underwent during the formation of living beings on the planet.

Hence the similarity in the structure of embryos in all classes of animals: fish, amphibians, reptiles, birds and mammals. However, according to modern data, Haeckel's law is not universal. After all, he does not explain why the larvae of insects and their adults differ so much, especially when it comes to incomplete transformation.

Another item, which is carefully studied by embryologists, are mutations. Thus, it was proved that the earlier chromosomal abnormalities arise, the greater their effect will be in the external manifestation after the formation of the organism. That is, the later the mutated stage, the less it will be noticeably phenotypic in an adult.

Embryology of animals

This section is important in the development of agriculture. The subject of study are the stages of formation of animal embryos. They are as follows:

• implantation;
• Gastrulation;
• Morula;
• blastula;
• Neurula;
• intussusception.

That is, animal embryology is the same as all its other sections, only a more narrowly specialized area at the object of study. It also considers mutations in the process of embryogenesis, the laws and mechanisms of their formation, and seeks ways to prevent and solve various problems. For example, diseases of animal organisms.

This is of great importance for poultry farming, cattle breeding, fish farming, veterinary issues and insemination problems.

Importance of achievements in the field of embryology

The most global achievement of modernity, which embryology could give a person, is the infertility forecasting and detailed observation of all the stages of the formation of human embryos. After all, it allows either to avoid the birth of children doomed to genetic diseases, or to correct the future mutational changes by medical intervention.

Today every pregnant woman is under the close supervision of doctors who, with the help of special equipment, can monitor and predict any situation in the development of the fetus.

Prospects for the development of this science

The main merits of this science are, of course, ahead. After all, the development of technical means does not stand still, and modern technologies allow you to intervene during almost all known life processes.

In the future, it is possible to open such processes at the stage of embryonic development, which will help to avoid fetal diseases, eliminate the phenomenon of infertility and relieve people of many pressing problems.