克洛德·贝尔纳

Claude Bernard (French: [klod bɛʁnaʁ]; 12 July 1813 – 10 February 1878) was a French physiologist. I. Bernard Cohen of Harvard University called Bernard "one of the greatest of all men of science". He originated the term milieu intérieur and the associated concept of homeostasis (the latter term being coined by Walter Cannon).

Life

Bernard was born on 12 July 1813 in the village of Saint-Julien, near Villefranche-sur-Saône. He received his early education in the Jesuit school of that town, then attended college at Lyon, which he soon left to become assistant in a druggist's shop. He is sometimes described as an agnostic, and even humorously referred to by his colleagues as a "great priest of atheism". Despite this, after his death Cardinal Ferdinand Donnet claimed Bernard was a fervent Catholic, with a biographical entry in the Catholic Encyclopedia. His leisure hours were devoted to the composition of a vaudeville comedy, and the success it achieved moved him to attempt a prose drama in five acts, Arthur de Bretagne. The latter, a tragedy concerning Arthur I, Duke of Brittany, was published only after his death. A second edition appeared in 1943.

In 1834, at the age of twenty-one, he went to Paris to present this play to critic Saint-Marc Girardin, but was dissuaded from adopting literature as a profession. Girardin urged him to take up the study of medicine instead. Bernard followed his advice, later becoming an interne at the Hôtel-Dieu de Paris. There, he met physiologist François Magendie, who served as physician at the hospital. Bernard became preparateur (lab assistant) at the Collège de France in 1841.

In 1845, he married Marie Françoise "Fanny" Martin for convenience; the marriage was arranged by a colleague and her dowry helped finance his experiments.……

Career

Bernard's first major work was on the functions of the pancreas. His discovery that the juices of the pancreas play a significant role in the digestive process won him the prize for experimental physiology from the French Academy of Sciences. His findings specifically showed that the pancreas secreted a fluid containing a lipolytic enzyme that split neutral fats into glycerol and fatty acids. Prior to his research, the function of the pancreas was poorly understood, with many physiologists considering it to be a gland of little significance. Bernard also discovered that introducing ether into the stomach or duodenum induced pancreatic secretions. The physiologist William Bayliss credited Bernard's work as influential in the latter's discovery of secretin, the first hormone to be isolated.

In perhaps his most famous experiment, Bernard discovered the glycogenic function of the liver. The liver, in addition to secreting bile, also produces the sugars that can cause hyperglycemia, which helped advance study of diabetes mellitus and its causes. In 1851, while examining the effects produced in the temperature of various parts of the body by each section of the nerve or nerves belonging to them, Bernard noticed that division of the cervical sympathetic nerve resulted in more active circulation and more forcible pulsation of the arteries in certain parts of the head.……

Honors and awards

Bernard received numerous honours, including the Baly Medal of the Royal College of Physicians in 1869. His Introduction à l’étude de la médecine expérimentale (1865) outlined his philosophy of scientific method and remains a foundational text in experimental medicine. Upon his death in 1878, he was given a state funeral, an honour rarely granted to scientists.

Scientific debates and critiques

Bernard's glycogenic theory drew criticism from Frederick Pavy, who argued that hepatic sugar originated from circulating blood rather than synthesis. The debate persisted for decades until biochemical evidence confirmed Bernard's interpretation. Later work by von Mering and Minkowski on pancreatic diabetes further refined his conclusions about glucose regulation.