Claude Bernard: Father of Experimental Physiology
Claude Bernard (12 July 1813 – 10 February 1878) was a French physiologist. He originated the term milieu intérieur and the associated concept of homeostasis, and is regarded as one of the greatest men of science.
Early Life and Education
Bernard was born on 12 July 1813 in the village of Saint-Julien, near Villefranche-sur-Saône. He received his early education at a Jesuit school in his hometown, then attended college at Lyon before leaving to work as an assistant in a druggist’s shop. In his leisure time, he wrote a vaudeville comedy and later a five-act tragedy titled Arthur de Bretagne, which concerned Arthur I, Duke of Brittany and was published only after his death.
At age twenty-one in 1834, Bernard traveled to Paris to present his play to critic Saint-Marc Girardin, hoping to pursue literature. Girardin discouraged him from that path and urged him to study medicine instead. Bernard followed this advice, eventually becoming an interne at the Hôtel-Dieu de Paris, where he met physiologist François Magendie.
Career and Achievements
Bernard became preparateur (lab assistant) at the Collège de France in 1841. In 1845, he married Marie Françoise “Fanny” Martin in an arranged marriage; her dowry helped finance his experiments. He was appointed Magendie’s deputy-professor at the college in 1847 and succeeded him as full professor in 1855.
His first major work focused on the pancreas. Bernard discovered that pancreatic juices play a significant role in digestion, specifically that the pancreas secreted a fluid containing a lipolytic enzyme that split neutral fats into glycerol and fatty acids. This work won him the prize for experimental physiology from the French Academy of Sciences. He also found that introducing ether into the stomach or duodenum induced pancreatic secretions. His research proved influential; physiologist William Bayliss later credited Bernard’s work as instrumental in Bayliss’s own discovery of secretin, the first hormone to be isolated.
Bernard’s most famous experiment involved discovering the glycogenic function of the liver. Beyond secreting bile, the liver produces sugars that can cause hyperglycemia, a finding that advanced the study of diabetes mellitus and its causes. In 1851, while examining nerve effects on body temperature, Bernard observed that division of the cervical sympathetic nerve resulted in more active circulation and stronger arterial pulsation in parts of the head. Months later, electrical excitation of the divided nerve produced the opposite effect. This discovery established the vasomotor system and the existence of both vasodilator and vasoconstrictor nerves.
Bernard’s research relied heavily on vivisection, a practice he championed in Europe. His use of animals in experiments, including the family dog, disgusted his wife and daughters. The couple was officially separated in 1869, and his wife subsequently campaigned against vivisection. Other scientists expressed discomfort with the practice as well; physician-scientist George Hoggan, who spent four months in Bernard’s laboratory, later wrote that his experiences there had “prepared [him] to see not only science, but even mankind, perish rather than have recourse to such means of saving it.”
Notable Events and Milestones
In 1860, Bernard was elected an international member of the American Philosophical Society. He was chosen to be the inaugural chair of physiology at the Sorbonne, though no laboratory was initially provided. After speaking with Bernard in 1864, Louis Napoleon built a laboratory for him at the Muséum national d’Histoire naturelle in the Jardin des Plantes. Napoleon III also established a professorship that Bernard accepted, leading him to leave the Sorbonne in 1868.
Bernard’s key conceptual contribution was milieu intérieur, the “internal environment.” He explained that the body is “relatively independent” of the outside world, and that a healthy internal environment adapts to deficiencies in the surrounding environment, maintaining physiological balance. This principle later became known as homeostasis, a term coined by Walter Cannon.
Awards and Honors
Bernard received the prize for experimental physiology from the French Academy of Sciences for his pancreatic research. In 1868, he was admitted a member of the Académie Française and elected a foreign member of the Royal Swedish Academy of Sciences.
Additional Resources
Bernard’s contributions to physiology fundamentally shaped modern biological science. More detailed information about his experiments, theoretical framework, and lasting influence on medicine and science is available through Wikipedia and other biographical archives dedicated to the history of physiology and experimental science.
Observer Voice is the one stop site for National, International news, Sports, Editor’s Choice, Art/culture contents, Quotes and much more. We also cover historical contents. Historical contents includes World History, Indian History, and what happened today. The website also covers Entertainment across the India and World.
