The way of an investigator : a scientist's experiences in medical research / by Walter Bradford Cannon.

  • Cannon, Walter B. (Walter Bradford), 1871-1945.
Date:
1945
Catalogue details

Licence: In copyright

Credit: The way of an investigator : a scientist's experiences in medical research / by Walter Bradford Cannon. Source: Wellcome Collection.

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    ing the cold of winter, and he hovers near the fire or the radi¬ ator as he did not when younger. Also he is likely to find the heat of a summer’s day especially uncomfortable; indeed, the death rate from heat stroke rises sharply after the seventh decade of life. Furthermore, the organs which prevent the ap¬ pearance of acid in the blood—the lungs, the heart, and the blood vessels—perform their functions less efficiently as one grows older. The chest becomes more rigid and thereby lessens the maximal intake and output of respired air; the highest heart rate induced by exercise gradually decreases, and the pumping of blood in a supreme effort is therefore slower with advancing years; and the blood vessels may become hardened and surrounded with obstructive connective tissue. Vigorous exertion, which produces acid and thus interferes with physio¬ logical efficiency, cannot be engaged in as it was in youth. The elderly man can look with amusement on the frolicsome and exuberant antics of a young puppy playing around a serene and indolent old dog and can say to himself, “I, too, played like that when I was young, and I was good for not much else. Now that I am old, I cannot be so energetic, but I can be use¬ ful to a degree not possible in those early years.” The physiological limitations of old age arise because our bodies are composed of a group of co-operative organs. All goes well as long as each one performs adequately its role in the complex. It is when an important organ becomes impaired and fails to “play the game” that a break occurs. Sometimes the kidneys fail, sometimes the heart, or the stomach, or the lungs; and then the partly broken man must learn to live within his limitations, a course which requires wisdom and patience. He may lead a helpful existence for many years; Holmes’s formula for longevity was to have a chronic disease and take care of it. Providentially, as long as the blood vessels of the brain supply that extraordinarily delicate and sensitive structure with an abundant supply of oxygen and sugar, clarity of the mental processes is preserved and pleasant social relations, as well as cherished personal activities, can be continued.