Presentation on theme: "Claude Bernard stated that there was no place in experimental medicine (the name he gave to physiology) for " doctrines " or “systems.“ “Systems," he wrote,""— Presentation transcript:
Claude Bernard stated that there was no place in experimental medicine (the name he gave to physiology) for " doctrines " or “systems.“ “Systems," he wrote," do not exist in Nature butonly in men's minds." He
PERCIVALL POTT (1714-88) He another well-known London surgeon, gave classical descriptions of the tuberculous disease of the spine, and of the fracture just above the ankle, still known respectively as Pott's disease and Pott's fracture. Pott was surgeon to St. Bartholomew's Hospital until his death at the age of seventy-four, as there was no retiring age in those days. From his house in Bow Lane he conducted a large surgical practice, attending such distinguished patients as Samuel Johnson and David Garrick. A lively and sociable man, he was popular with all ranks of society.
WILLIAM HEWSON (1739-74) He was a brilliant young man who demonstrated the existence and function of the lymph vessels in animals, and established the fact that the coagulation of the blood was due, not to a solidification of the corpuscles, but to a substance in the plasma which he called “coagulable lymph," later known as "fibrinogen." Hewson died from septicaemia following a dissection wound at the age of thirty-six.
Robert Knox In 1829 there died in William Hare's lodging-house in the West Port of Edinburgh an old man who had failed to pay his bill. Assisted by Thomas Burke, another of his lodgers who, like himself, was an Irishman, Hare conceived the idea of clearing the debt by the sale of the debtor's body to Dr. Knox for. Encouraged by this success, the two ruffians embarked upon a series of murders, luring their victims into the house, plying them with drink and then suffocating them, so that the body showed no trace of violence.
CLAUDE BERNARD (I8I3-78) His first work related to digestion. By a series of carefully planned experiments, he showed that digestion was not completed in the stomach, as had been believed, but that gastric digestion was only a preparatory act. Digestion was continued in the intestine, through the action of the pancreatic juice or secretion. It was during this series of experiments that one of his dogs, having a cannula fixed in its pancreatic duct, escaped from the laboratory, and was brought back by the irate owner, an inspector of police.
The next important discovery, that of glycogen, was also the outcome of systematic and planned experiments. Bernard proved that the liver did not merely secrete bile ; it also produced sugar, and this function was independent of sugar in the diet. There was, in fact, an “internal secretion," or milieu interieur, and in giving it this name Bernard paved the way for the discovery of the numerous " hormones " which we now recognize. Moreover, the production of sugar by the liver showed that the animal body could build up substances as well as destroy them.
A third discovery was that of the vasomotor mechanism. Bernard was working at the subject of animal heat when he noted that division of the cervical sympathetic nerve in a rabbit raised the temperature on that side of the head and neck. With characteristic insight he saw the significance of this side issue, and turned aside from his main quest to ascertain how the nerve could influence temperature. While investigating the function of the submandibular gland, he showed that the sympathetic nerve was the constrictor of the blood vessels ; the chorda tympani was the dilator. Thus were the fundamental facts of vasomotor physiology made known.