Walter Bradford Cannon (1871-1945) was an American physiologist.

Contents

1 Use of salts of heavy metals in X-Rays 2 Fight or Flight 3 Homeostasis 4 Dry Mouth 5 American Physiological Society 6 External links

Use of salts of heavy metals in X-Rays

He was one of the first researchers to mix salts of heavy metals (including bismuth subnitrate, bismuth oxychloride, and barium sulfate) into foodstuffs in order to improve the contrast of X-ray images of the digestive tract. The barium meal is a modern derivative of this research.

Fight or Flight

In 1929, he coined the term fight or flight to describe an animal's response to threats.

Homeostasis

He developed the concept of homeostasis, and popularised it in his book The Wisdom of the Body, published in 1932 by W. W. Norton, New York.

Cannon presented for tentative propositions to describe the general features of homeostasis

1. Constancy in an open system, such as our bodies represent, requires mechanisms that act to maintain this constancy. Cannon based this proposition on insights into the ways by which steady states such as glucose concentrations, body temperature, and acid-base balance were regulated.

2. Steady-state conditions require that any tendency toward change automatically meets with factors that resist change. An increase in blood sugar results in thirst as the body attempts to dilute the concentration of sugar in the extracellular fluid.

3. The regulating system that determines the homeostatic state consists of a number of cooperating mechanisms acting simultaneously or successively. Blood sugar is regulated by insulin, glucagons, and other hormones that control its release from the liver or its uptake by the tissues.

4. Homeostasis does not occur by chance, but is the result of organized self-government.

Dry Mouth

He made a basic theory called Dry Mouth Theory, in which he said people get thirsty because their mouth gets dry. He did an experiment on two dogs. He cut their throat and injected a small tube. Then he would water in their mouth and every time the water would through the tube, but in their mouths. He found out that these would lap up the same amount of water.

American Physiological Society

He was President of the American Physiological Society from 1914 to 1916.

External links

6th APS President at the Americal Physiological Society.

Walter Bradford Cannon: Experimental Physiologist, a biographical article by Edric Lescouflair, dated 2003.

Chapter 9 of Explorers of the body, by Steven Lehrer (contains information about X ray experiments).