Claude Bernard, ( July 12, 1813— Feb. 10, 1878), French physiologist known chiefly for his discoveries concerning the role of the pancreas in digestion, the glycogenic function of the liver, and the regulation of the blood supply by the vasomotor nerves. On a broader stage, Bernard played a role in establishing the principles of experimentation in the life sciences, advancing beyond the vitalism and indeterminism of earlier physiologists to become one of the founders of experimental medicine. His most seminal contribution was his concept of the internal environment of the organism, which led to the present understanding of homeostasis—i.e., the self-regulation of vital processes.
Bernard’s father, Pierre, was a winegrower; his mother, Jeanne Saulnier, was of peasant background. When Claude was very young, his father failed in a wine-marketing venture and tried to make ends meet by teaching school. Despite his efforts, the family never prospered, and when he died, the survivors were left in debt. Educational opportunities were scarce for a poor winegrower’s son in the France of Louis XVIII. The boy studied Latin with the local priest and then was enrolled in a Jesuit-conducted school at Villefranche, where no natural science was taught. At 18 Bernard ended his secondary schooling at Thoissey without a diploma and was apprenticed to an apothecary in a Lyon suburb.
Bernard’s days were spent in menial tasks relieved by errands to a veterinary school or, on his rare times off, by visits to a theatre.His employer was not pleased, however, and the apprenticeship came to a halt, the youth returning home in July 1833.Bernard enrolled that same winter in the Faculty of Medicine in Paris and, in due course, was admitted as an extern in the hospitals. Outwardly reserved and even shy at that time, he had an inner strength that was to overcome poverty and discouragements. Of 29 students passing the examination for the internship, Bernard ranked 26th. Serving in Paris hospitals were the celebrated doctors Pierre Rayer and François Magendie, and Bernard studied under the latter at both the Hôtel-Dieu and the Collège de France. Magendie noticed Bernard’s skillful dissections and took him on as a research assistant.
An autopsy of the rabbits yielded an important discovery concerning the role of the pancreas in digestion: the secretions of the pancreas broke down fat molecules into fatty acids and glycerin. Bernard then showed that the principal processes of digestion take place in the small intestine, not in the stomach as was previously believed.His work on the pancreas led to research on the liver, culminating in his second great discovery, the glycogenic function of the liver.Bernard also conducted important studies on the effects of such poisons as carbon monoxide and curare on the body. He showed that carbon monoxide could substitute for oxygen and combine with hemoglobin, thereby causing oxygen starvation.
Bernard’s health had declined precipitously in the autumn of 1877. On New Year’s Day he caught cold, and shortly afterward inflammation of the kidneys set in. Soon he was confined to his bed. At his death Bernard was accorded a funeral arranged and financed by the government, the first ever granted to a scientist in France.