Claude Bernard( Outstanding French naturalist and physiologist)
Comments for Claude Bernard
Biography Claude Bernard
(1813-1878) - eminent French naturalist and physiologist - was the son of peasant wine grower from the small village of Saint-Julien near Villefranche-on-Sonya.
Having a higher medical education, Claude Bernard was a medical practice, but soon changed his position of hospital doctors in place preparator in the laboratory of the famous physiologist, Magendie. Here he began to conduct independent research. Already the first published his work showed that by them - a scientist with a great future.
Six years. Bernard received a professorial position at the College de France (high school in Paris), and with it the laboratory. It was raw, almost a dark room in the basement, and long-term work in it said: the scientist gravely ill. But ill he continued to work.
For years, Claude Bernard investigated the processes of digestion and assimilation of food. He was able to examine the salivary glands, the role of gastric and intestinal juice. Pancreas, it turned out, was very important in the digestion of fats.
Starch and sugar featured prominently in the diet. But as they learn what happens to them in organizmeN Where does the sugar in any kroviN Many questions arise when trying to clarify the fate of body encountering starch. Much of any 'intelligence' was taken to scientists in search of 'road' starch. This 'road' has been found, and she brought Bernard to the liver.
The liver has long been interested in the doctors and physiologists. Its size, the abundance of blood, large veins, gall bladder - all this attracted their attention. Yet, until studies of Claude Bernard liver remained unexplored.
Caught in the body begins to break down starch in the mouth, under the action of saliva. In the intestine it is converted to sugar, insoluble substance is easily soluble. Sugar is carried away by blood, through the portal vein enters the liver. And here he turns into starch, but otherwise - in the animal starch, or glycogen. Glycogen is deposited in the liver cells. As necessary, he turns into sugar - glucose, which enters the blood. Glucose (blood) - glycogen (liver) - glucose (blood) - this is the way and these are the transformations of carbohydrates learned intestine, and without proper liver function, they can not happen.
Before Bernard believed that glucose enters the bloodstream directly from the diet: to act in the intestine for some amount of starch or sugar, digest and transformed into grape sugar - glucose, and blood glucose sustained it throughout the body.
'No, - said Claude Bernard - the situation is more complicated'. And he proved it.
In the working muscle glucose is consumed, the amount in the blood decreases. Then a new portion of glycogen in the liver are converted to glucose enters the blood and the blood carries them to the working muscles, the muscle provides a kind of fuel.
When your food in the body heat is. Anyone can spot it in yourself. Bernard explored, as is the distribution of heat in the body. It turned out that the most warm blood in the liver - the liver gives the body a lot of heat. In the heart of the right half of the blood (venous) warmer than the left half of the blood (arterial): passing through the lungs, the blood is cooled somewhat.
Blood vessels do not remain unchanged: their clearance may decrease and increase, in other words, the vessel may narrow and widen. Changes the lumen of the vessel, the other is the number of filling his blood: it is a rush, it pours. And connected with this release of heat and skin, the regulation of body temperature.
What controls the changes in the lumen of blood vessels and the occurrence of these izmeneniyaN Bernard suggested that they occur under the influence of sympathetic nerves. Indeed, if the cut right cervical sympathetic nerve, the right ear rabbit becomes warmer left. Obviously, there is expansion of blood vessels, increases blood flow.
How to see these izmeneniyaN through the delicate skin of the rabbit ear clearly visible small blood vessels, transection of the sympathetic nerve leads to vasodilatation, and the ear pink. These experiences Bernard argued vasomotor role of sympathetic nerves. Stimulation of the electric current of the cervical sympathetic nerve causes constriction of blood vessels in the rabbit's ear, and it is markedly pale.
Tell about all the discoveries of Claude Bernard in a small article can not be: this requires a thick book. Over 35 years of his scientific career he published 180 papers. Almost every section of Physiology, made a brilliant opening. He studied the effect of poisons and composition of urine, gas pressure and the color of blood, carbon monoxide and poisoning it, the work of the nerves and the action of a variety of drugs.
But besides all this, the scientist has published many papers on general issues of physiology of healthy and sick person, the role of experience in research, the importance of physiology in medicine. 'Physiology - it is a scientific core, which kept all the medical science "- he asserted, adding that the development of medicine and laboratory experiments are no less important than hospital and observation over the course of the disease.
'The doctor of the future physician-experimenter'. This was sure a skilled experimentalist Claude Bernard. And his example he showed how important the laboratory and experience to the science of healthy and sick man.