He was playwriting; They said to be a doctor: Who is Claude Bernard?

(1813-1878) French physiologist. He is considered the founder of experimental medicine and physiology with his research on the digestive and nervous systems.

He was born in July 1813 in the town of Saint-Juhen in the Rhone province in the Beaujolais region. Claude Bernard, who could not find a regular education because he was the son of a middle-class vineyard, enrolled in the Jesuit school in Villefranche after learning Latin from the village priest. Afterward, he started to study in Thoissev, a college that focused especially on literary culture and did not even include physics and natural sciences in its program, but due to the increasing financial problems of the family, he left his education unfinished in 1831 and became an apprentice to a pharmacist in Lyon.

At that time, his biggest dream was to become a well-known playwright. When he earned some money from a vaudeville titled La Rose du Rhöne ("The Rose of the Rhone"), which he wrote in his spare time, he quit his job at the pharmacy and took up writing the rub. When he finished his five-act tragedy Arthur de Bretagne in 1834 and took it to Paris to the famous critic Saint-Marc Girardin, he was very hopeful of his work and its success. However, Girardin advised the 21-year-old to stop writing plays and attend medical school.

Claude Bernard heeded this critic's advice and barely continued his medical studies, lecturing at night to cover his expenses. Indeed, Claude Bernard, who was suffocating with money and had never had a solid education in the natural sciences, was one of the lowest-graded students when he finished school in 1843.

Claude Bernard had the opportunity to work with a valuable physician like Magendie while he was interning in hospitals in Paris in 1839. After graduating from school, he started to work as Magendie's assistant at Hötel-Dieu and College de France. Although he benefited greatly from his teacher's experience and knowledge, he did not want to settle for his research assistantship. Although he applied to teach at the medical faculty in 1844, he was unsuccessful in the exam. He was then married to the daughter of a rich Parisian doctor, but this marriage brought him nothing but new problems. Despite his wife's wishes to become a private doctor and his constant opposition to experiments on live animals in the basement of his house, he gradually reduced his clinical work and devoted all his time to laboratory research. In 1847 Magendie left part of his lectures at the College de France to this highly trusted student. Berna, who received his doctorate degree with his thesis that had great repercussions in 1853, was appointed to the professorship of the general physiologist chair established for him at the Sorbonne the following year, and to replace his teacher in 1855 after Magendie's death.

After 1860, Claude Bernard, who started to spend his spare time in the town where he was born, concentrated on the philosophy of science. He had separated from his wife and had a platonic relationship with a Russian student of Jewish descent, Marie Raffalovic. At that time his health had deteriorated; Since the disease that started in his liver and pancreas progressed to kidney inflammation, he left his chair at the Sorbonne to his student Paul Bert in 1868 and continued his lectures only at the College de France. He was elected to the French Academy in 1869, and in the same year, he was appointed president of the Academy of Sciences, of which he has been a member since 1854. When Claude Bernard, whose health deteriorated after giving his last lecture at the College de France on December 28, 1877, died in Paris on February 10, 1878, he was buried with a national ceremony that had never been done to any scientist before him.

He received the Experimental Physiology Award of the Academy of Sciences four times for his work. He was awarded the Legion d'honneur by Napoleon and the Copley medal of the Royal Society in London in 1876.

Claude Bernard's dissertation titled "On Stomach Juice and Its Role in Nutrition", prepared in 1843, was about digestion. The first important findings of his research, which he started at the College de France in 1847, are also related to digestion. In these studies on animals, he showed that by giving the food directly to the duodenum, a large part of the digestion takes place in the small intestine, not the stomach. This finding was a new approach that would invalidate old knowledge. In addition, Claude Bernard, who determined that pancreatic secretion also plays an important role in digestion, clarified for the first time that fat molecules are broken down into fatty acids and glycerol. This work, which received the Experimental Physiology Award of the Academy of Sciences in 1847, was confirmed by the knowledge of medicine and biology gained in the next century, and the new information added to the findings of Claude Bernard revealed how basic concepts developed at the molecular level.

Beginning in 1850, Claude Bernard focused his research on the function of the liver. His work titled "On A New Function of the Liver in Man and Animal", which he prepared that year, received the 1851 Experimental Physiology Award of the Academy of Sciences, while his doctoral thesis, which again examined the function of the liver in detail in 1853, won the praise of the most famous medical scholars of the time. In 1856, Claude Bernard, who detected the presence of a starch-like substance in the liver and named it "glycogen," also showed that this complex molecule is produced by the body from sugar. This examination was the first proof that the body can produce high-structured substances spontaneously by utilizing simple molecules. Continuing his studies, Claude Bernard was the first to explain that glycogen molecules act as a store. According to his explanation, when the amount of sugar in the body increases, it is converted into glycogen and stored, and when necessary, these glycogen molecules can be converted into sugar to provide energy to the body. The mentioned construction-destruction processes are a process to keep the amount of sugar in the blood at a certain level in order to maintain certain balances in the body. As a matter of fact, subsequent studies confirmed the findings of Claude Bernard by revealing that the substances playing a role in this mechanism are controlled by the hormones insulin and glucagon secreted by the pancreas. Indeed, insulin ensures that excess sugar is converted into glycogen in the liver and stored, while glucagon ensures that the glycogen in the liver cells is broken down into sugar in order to increase the blood sugar that decreases during fasting. If the pancreas fails to synthesize insulin or secrete it enough, the level of blood sugar cannot be controlled and leads to diabetes. Claude Bernard's studies on glycogen metabolism have been an important step in the understanding of diabetes, which affects millions of people, and in the search for treatment options.

Claude Bernard also investigated the effects of toxic substances and anesthetics on the human body, especially the border system, and showed that carbon monoxide could bind to hemoglobin by taking the data of oxygen and eventually lead to oxygen deficiency. As a result of his experiments with curare, he was the first to describe the paralyzing effect of toxic substances on motor nerves, and these findings opened new horizons in the field of experimental pharmacology by drawing attention to the effects of drugs on the human body.

The value of Claude Bernard's scientific work rests not only on his power of observation and experiment but also on the importance his method gives to hypothetical. Claude Bernard, who argued that the assumption should not gain weight in a way that would affect the researcher during the experiment, but should lead to a solid result synthesis by establishing the connection between the events, contributed greatly to the establishment of the experimental principles in natural sciences. Despite the limited technological possibilities of his age, Claude Bernard, whose every finding was confirmed by today's medical knowledge, and who instilled the importance of the experimental method in his students, is considered the founder of experimental medicine.