THEODOR SCHWANN: BIOGRAPHY, CELL THEORY, OTHER CONTRIBUTIONS - ARTE - 2025

Theodor Schwann (1810-1882) was a German physiologist considered to be the founder of modern histology, thanks to his contributions to cell theory and his definition of the cell as the fundamental unit of animal structure.

He studied at the University of Bonn and it was there that he met Johannes Peter Müller, who was later his tutor and with whom he was a research assistant for some years. JP Müller was characterized by his experimental methods and had a great influence on the works of Schwann.

Theodor Schawann made important contributions to cell theory. Source: Henry Smith Williams

From early in his professional life, Schwann devoted himself to research and began to contribute significantly in different areas. The discovery of pepsin and valuable contributions to cell theory are attributed to him; In addition, he invented a device that made it possible to measure muscle strength.

Schwann studied his doctorate at the University of Berlin and successfully completed his studies, as his doctoral thesis was highly recognized by doctors and professors of the time. Throughout his life he devoted himself to the study and understanding of the human system and made various contributions to medicine.

His greatest contribution was made together with various scientists such as Carl Woese, Robert Hooke and Jakob Schleiden, among others: the cell theory. This theory, fundamental to biology, establishes how organisms are constituted and what role cells play both in the creation of life and in the main characteristics of living beings.

The work carried out by Schwann was recognized by the most important scientists in the international arena. He was awarded the Copley Medal in 1845 and in 1879 he was made a member of the Royal Society and the French Academy of Sciences.

Biography

Friedrich Theodor Schwann was born on December 7, 1810 in Neuss, near Dusseldorf, Germany.

His father was a goldsmith and later ventured into the printing business. Since Theodor was little, his father always involved him in building small machines, so the future scientist developed a practical mind.

Studies

He completed his primary studies at the Jesuit College of Cologne and in 1829 began his studies in medicine at the University Bonn, where he was a pupil of Johannes Peter Müller. Müller was a forerunner of comparative physiology and anatomy. He was characterized by his experimental methods and had a great impact on his pupil.

Years later he moved to study at the University of Wüzburg, where he received his clinical training. Later he enrolled at the University of Berlin, where he met up with JP Müller.

At the University of Berlin he obtained his doctorate in 1834. His thesis De necessitate æris atmosphærici ad evolutionem pulli in ovo incubated dealt with the need for the presence of oxygen in the development of chicken embryos and was recognized by leading scientists.

He had a good relationship with JP Müller and worked together with him at the Anatomical Museum in Berlin; during that time he devoted himself mostly to experimental research and continued to assist him in his physiology experiments.

First discoveries

In 1836, at just 26 years old, he discovered pepsin and the importance of bile in the digestive process. Three years later, he devoted himself to studying the principles of cell theory previously proposed by various scientists.

That year (1839) he moved to Belgium and there he began to teach Anatomy classes at the Catholic University of Louvain. Later, in 1948, he devoted himself to teaching at the University of Liège in the chair of Comparative Physiology and Anatomy. He was there until 1880.

Teaching and death

During the years in which he was in Belgium, he detached himself from research and focused on teaching. He managed to develop in young people a feeling towards him of respect, affection and admiration.

After his retirement, he worked until his death on a work through which Theodor sought to tell his atomicist perspective on physical phenomena, and became involved in matters concerning theology.

However, the work he was working on could not be completed, since Schwann died on January 11, 1882, in Cologne (Germany), when he was 71 years old.

Cell theory

The cell theory, fundamental in biology, explains the composition of living beings and the importance of cells in life.

This theory could be developed through the contributions of various scientists, especially regarding its principles. In addition to Schwann, Robert Hooke, MJ Schleiden and Robert Brown, among others, were also highly influential.

-Background

The study of cells began long before Theodor Schwann's investigations. Like all theories, its principles are based on past observations and facts that are synthesized through scientific methods.

Microscope

Of course, the invention of the microscope was instrumental in advancing cell theory.

The invention of the microscope in the 17th century is attributed to Zacharias Jansen, although at the time of his invention (1595) he was very young, so it is believed that his father was the one who made it and he perfected it. In any case, after this time the more detailed studies began through the use of this instrument.

The first sighting of cells through a microscope was made by Robert Hooke in 1663. He was looking at a piece of cork and noticed that the surface was not completely smooth, but rather porous; he could see dead cells in the holes in said cork. After this he coined the term "cell".

Two years later, in 1665, Hooke shared his work and this discovery in his Micrography: Physiological Descriptions of Tiny Bodies.

Years later, Marcelo Malpighi and Nehemiah Grew were the first scientists to observe living microorganisms through a microscope. In 1674 Anton Van Leeuwenhoek observed for the first time protozoa in deposited water and red blood cells in blood.

Between 1680 and 1800, no great advances occurred in the study of cells. This could have been due to the lack of quality lenses for microscopes, since many hours had to be spent observing using existing microscopes.

First statement

In 1805 Lorenz Oken, renowned German philosopher and microscopist, declared what is considered the first statement of the cell theory, in which he proposed that "all living microorganisms originate from and consist of cells."

Around 1830 Robert Brown discovered the nucleus, which was not limited to the epidermis but was also found on the hairy surface and in the internal cells of tissues. Brown conducted his studies with plants and determined that what he discovered was not only manifested in orchids, but also in other dicotyledonous plants.

After Brown's discovery, MJ Schleiden, professor of botany at the University of Jena, became interested in such work and confirmed the importance of cell components. In fact, he thought that the nucleus was the most important part of the cell, since the rest arises from it.

After the improvement of the microscopes, it was possible to study in more detail using this instrument, and it was precisely this advance that was decisive for the study made by Theodor Schwann.

-Schwann's contributions

Specifically, Schwann was based on the principles proposed by Schleiden and contributed important concepts for the development of the theory. The elements proposed by Schwann are currently part of the principles of the theory.

In his work Microscopic investigations on the concordance of the structure and growth of plants and animals (1839), this scientist proposed that all living beings are made up of cells or products of these, and that cells have independent life, although this depends directly on the life of the organism.

In this work Schwann also identified different types of cells. In addition, he focused on defining the internal components of these, although he was wrong about the way in which they can arise, since he proposed that they could do so through the assembly of cellular fluids.

Likewise, through his study with various instruments, Theodor Schwann identified that the phenomena of cells can be classified into two groups: those that are related to the combination of molecules for the formation of cells and others related to the result of chemical changes.

-Conclusions

The three conclusions proposed by Schwann in his work were the following:

- The cell is the main unit of the structure, physiology and organization of living beings.

- The cell has a dual existence as a building block in the formation of organisms and as an independent entity.

- Cell formation occurs through the free cell process, similar to crystal formation.

The first two conclusions were correct, but the last one was wrong, since years later Rudolph Virchow proposed the correct process through which cells are formed by division.

-Modern principles

Currently there are considered modern principles of cell theory. These state the following:

- All living beings are made up of cells, bacteria and other organisms, regardless of the level of biological complexity of said living being; a cell could be enough to generate life.

- Cells are open systems that interact with their environment and exchange information and resources. In this sense, cells are capable of containing all the vital processes of the body.

- Each of the cells comes from an existing prokaryotic cell.

- Cells have information that is transmitted from one to another, during cell division.

- All the energy flow of living organisms occurs within cells.

Cell theory is of vital importance in biology today, and principles have been added to it thanks to what has been found through ultrastructural research and molecular biology.

Other contributions and discoveries

Fermentation

In 1836 Theodor Schwann studied the fermentation process through experiments with sugar and discovered that yeast caused this process.

Pepsin

That same year, when he was in the company of Müller, he discovered pepsin, the first animal enzyme discovered. He came to this finding after extracting fluids that are part of the stomach lining.

Pepsin is a digestive enzyme created by glands in the stomach and is involved in the digestive process. That is, it is of utmost importance for the body.

Striated muscle

At Müller's initiative, Schwann began research into contraction of muscles and the nervous system, and discovered a type of muscle at the beginning of the esophagus called striated muscle.

The composition of this muscle is made up of fibers surrounded by a large cell membrane and its main unit is the sarcomere.

Metabolism

In addition to all the study carried out to understand the functioning of cells and their importance, Theodor is also credited with the concept of metabolism as the process of chemical changes that occur in living tissue.

This notion has been widely used for many years to explain the set of processes that are generated in the organism of living beings.

Embryology

Schwann also proposed the principles of embryology after observing the egg, which begins as a single cell and, over time, becomes a complete organism.

Checking for the error in spontaneous generation

In 1834 he began studies related to spontaneous generation, a hypothesis that argued that some living beings arise spontaneously from matter, either organic or inorganic.

His experiment was based on exposing a boil in a glass tube to hot air. Thus he was able to realize that it was impossible to detect microorganisms and that there were no chemical changes in the composition of the boil.

It was at that moment that he became convinced that this theory was wrong. Years later, it became obsolete after a series of advances related to it.

Those who supported the theory of spontaneous generation argued that heat and acid altered the air in such a way that they prevented the spontaneous generation of microorganisms. In 1846 Louis Pasteur definitively proposed that such a theory did not make sense, after experimenting with flasks and a long, curved tube.

References

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