|HISTORY OF MEDICINE
|Year : 2017 | Volume
| Issue : 4 | Page : 299-301
Theodor Schwann: A founding father of biology and medicine
Tony Abraham Thomas
Department of Continuing Medical Education, Christian Medical College, Vellore, Tamil Nadu, India
|Date of Web Publication||17-Nov-2017|
Tony Abraham Thomas
Department of Continuing Medical Education, Christian Medical College, Vellore - 632 002, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Theodor Schwann is best remembered for the eponymous Schwann cell that he studied and described in his microscopic studies of nervous tissue. However, his most important contribution to science would be the fact that he was one of the founders of the 'Cell doctrine' which proposed that all living beings were made of fundamental units called cells - a foundational principle on which rests much of our understanding of biological science. Schwann was one of the first scientists to break away from vitalism to lean toward a mechanistic or physico-chemical explanation of living processes which proposed that the biological processes in cells and living beings could be explained by physical and chemical phenomena. He was also involved in describing the physiology of bile and the enzyme pepsin which furthered our understanding of the physiology of digestion. His contributions to biology and medicine has paved the way for the emergence and blooming of several fields of study such as microbiology, pathology, histology and the principle of antibiotics.
Keywords: Cell doctrine, Schwann cell, Theodor Schwann
|How to cite this article:|
Thomas TA. Theodor Schwann: A founding father of biology and medicine. Curr Med Issues 2017;15:299-301
| Introduction|| |
Although most well known for the Schwann cell that bears his name, Theodore Schwann, the German physiologist, has a number of discoveries and accomplishments to his credit. He was one of the early scientists at the dawn of biology as we know it today, involved in clarifying our understanding of the basic and fundamental principles of cellular life, its structure, and its physiology. The “cell doctrine” which proposed that all living beings were made of fundamental units called cells was one such foundational principle on which rests much of our understanding of biological science and Schwann was one of the founders of this fundamental principle. He was also involved in the microscopic study of muscle and nerve cells, blood vessels and the physiology of digestion, making several pathbreaking discoveries during his lifetime, thus laying the foundation for the emergence of other branches of science.
| Early Life and Childhood|| |
Theodor Schwann [Figure 1] was born at Neuss near Dusseldorf in Prussia (modern-day Germany) on December 7, 1810. His father was a goldsmith and was involved later in the printmaking business. In his childhood, young Theodor was known to have been involved in constructing little machines in his childhood, no doubt having inherited a practical mechanical bent of mind from his father. After completing his school studies in the Jesuit College of Cologne, he came under the tutorship of Johannes Müller at the University of Bonn in 1829. Müller was a pioneer in comparative anatomy and physiology, especially known for his experimental methods and he was to have a significant impact in shaping his protégé. Schwann assisted him in his experiments in physiology and was inspired to pursue a medical career. He had his clinical training in Würzburg and went on to the University of Berlin to study once again under his mentor Müller who had now been appointed as Professor in Anatomy and Physiology at the university. Schwann's thesis work focused on the necessary role of oxygen in the development of the chicken embryo, and he obtained his MD degree in 1834. Following this, he continued assisting Müller in his physiology experiments, and the 4 years spent under his supervision laid the foundation for the remarkable scientific advances that he would pioneer.,,
| Schwann Cell|| |
Schwann was particularly interested in the cellular structure of muscle and nerve tissues, and this led to his discovery and description of the Schwann cells and the role it played in providing the envelope covering nerve fibers called the Schwann cell sheath (which later came to be known as the myelin sheath). The myelin sheath is a characteristic feature of myelinated nerve fibers in the central nervous system, and its presence has implications on the speed of conductivity of nerve impulses besides other functions. He was also an initiator of work on muscle cell contractility and established the first tension-length diagram.,, This work was then carried on by Du Bois-Reymond and Helmholtz and paved the way for the development of the field of neuromuscular physiology.
| Pepsin|| |
In 1836, while investigating the physiology of digestive processes with Müller, he isolated a chemical substance that was responsible for digestion in the stomach. This enzyme, which he named pepsin, was the first enzyme to be prepared from animal tissue.,
| Vitalism and Spontaneous Generation Discredited|| |
The prevalent understanding of life and biological processes at that time was based on a theory called “Vitalism.” According to this theory, “living organisms are fundamentally different from nonliving entities because they contain some nonphysical element or are governed by different principles than are inanimate things.”, This principle that gives life was known as the “vital spark” or “energy,” which was considered nonphysical. Schwann was one of the first scientists to break away from vitalism to lean toward a mechanistic or physicochemical explanation of living processes which proposed that the biological processes in cells and living beings could be explained by physical and chemical phenomena without the need for a nonphysical entity. The experimental work of Schwann using yeast cells also paved the way for the discrediting of “spontaneous generation” as a theory to explain the genesis of living processes. In the process, he also described the nature of the yeast cell.
| Cell Doctrine|| |
Schwann was also one of the founders of the cell doctrine, which would revolutionize biology and provide the basis for understanding all of biology and biological processes. A German botanist named Matthias Jakob Schleiden [Figure 2] had discovered in 1837, that there were fundamental units called cells in plants, and this agreed with the findings of Müller and his protégé Schwann who had found similar cells in their microscopic studies. The exchange of ideas between Schwann and Schleiden was thought to have taken place over a dinner when Schwann realized that he had seen cellular structures in his microscopic studies of animal nervous tissue (notochord), similar to the one his colleague was describing in plant tissues.,, Schwann connected the dots and realized that cells were the “elementary units of life” for both plants and animals and went on to describe this in his work titled “Microscopical Researches into the Accordance in the Structure and Growth of Animals and Plants” which was published in German in 1839 and later translated into English in 1847 by the Sydenham Society. This finding was confirmed by many other scientists and led to the understanding that all living organisms were composed of fundamental units called cells and products derived from cells.
|Figure 2: Rudolf Virchow (left) and Matthias Jacob Schleiden, cofounders of the Cell Doctrine along with Theodor Schwann.|
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In a scientific milieu that breathed the air of vitalism, this was a revolutionary concept that would have far-reaching consequences. Later, in 1857, Rudolf Virchow a pathologist, built on this doctrine and set forth the maxim, “Omnis cellula e cellula”- that every cell arises from another cell. By 1860, the cell doctrine was established and would go on to open up avenues for new research like the “germ theory” by Pasteur and blooming of the streams of microbiology, cell biology, histology, infectious diseases, and pathology. This doctrine also paved the way to other discoveries that developed our understanding of cellular processes that underlie the physiology of health and disease.
| Later Academic Life|| |
In 1838, Schwann was appointed to the chair of Anatomy at the Université Catholique de Louvain in Belgium where he served for 9 years and during this period wrote a paper describing the physiological role of bile in digestion based on his experiments in dogs. After this, he went on to join the University of Liége in the year 1848, as a professor in Anatomy and Physiology. This latter aspect of his academic life was not marked by the prodigious amount of work and discoveries that marked his earlier tenure in Berlin though he continued to remain in touch with academic science and was involved in perfecting experimental techniques and instruments that aided these experiments.,,,
Theodor Schwann was a devout Catholic and was known to be a gentle soul. In his later years, he grappled with the philosophical and theological implications of his discoveries, and this was to lead to life in isolation, fraught with existential questions which he discussed in several publications and in a treatise. The debate is far from over and even today scientists, philosophers and theologians continue to grapple with these issues and the new areas of ignorance opened up by every surge of knowledge. Schwann died in Cologne on January 11, 1882, 3 years after his retirement.
| Conclusion|| |
Despite the relative scientific penury of his later years, there is no doubt that Schwann was a tremendous force in the advancement of our understanding of the basic tenets and principles of biological science. The cell doctrine, in particular, was a revolutionary step forward, and the impact of that alone is still felt in the modern age, in the various branches of Biology and Medicine that we study today. The germ theory of Pasteur, the growth of histology and pathology, principles of antisepsis, and production of antibiotics are only some of the numerous applications that emerged from this doctrine which has contributed tremendously to human health and relief from pain.
Paul Ehrlich who was awarded The Nobel Prize in Physiology or Medicine in 1908 for his work on immunity had this to say of Schwann at his Nobel Lecture – “The history of the knowledge of the phenomena of life and of the organized world can be divided into two main periods. For a long time anatomy, and particularly the anatomy of the human body, was the alpha and omega of scientific knowledge. Further progress only became possible with the discovery of the microscope. A long time had yet to pass until through Schwann the cell was established as the final biological unit. It would mean bringing coals to Newcastle were I to describe here the immeasurable progress which biology in all its branches owes to the introduction of this concept of the cell concept. For this concept is the axis around which the whole of the modern science of life revolves.”
Theodor Schwann was a giant in his field, and the ripples that Schwann initiated will no doubt continue in the years to come, spawning new research in medicine and in our understanding of biological life.
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Conflicts of interest
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[Figure 1], [Figure 2]