Walter Cannon

Walter Bradford Cannon (Prairie du Chien, Wisconsin, October 19, 1871 – Lincoln, Massachusetts, October 19, 1945) was an American physiologist.

Biography
He was married to Cornelia James Cannon, a best-selling author. Although not mountaineers, during their honeymoon the couple were the first, on July 19, 1901, to reach the summit of the unclimbed southwest peak (2657 m or 8716 ft) of Goat Mountain, between Lake McDonald and Logan Pass in what is now Glacier National Park. The peak was subsequently named Mount Cannon by the United States Geological Survey.

His son was Dr. Bradford Cannon (December 2, 1907–December 20, 2005 ), a pioneer in the field of reconstructive surgery, specialising in burn victims. He was the first chief of plastic and reconstructive surgery at Massachusetts General Hospital and is credited with saving the lives of thousands of soldiers maimed during World War II. Bradford Cannon and his wife Ellen DeNormandie Cannon (died 2003) lived in Lincoln, Massachusetts.

His daughter is Marian Cannon Schlesinger, a painter and author living in Cambridge, Massachusetts.

His grand-son Robert Laurent Cannon is a pilot, living in Centennial, Colorado. There are two other grand-sons, Dr. Walter B. Cannon, a thoracic surgeon of Palo Alto, California, and Dr. Woodward Cannon, a general surgeon of Raleigh, North Carolina. His grand-daughter is Sarah Cannon Holden, also of Lincoln, Massachusetts.

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 1915, he coined the term fight or flight to describe an animal's response to threats (Bodily Changes in Pain, Hunger, Fear and Rage: An Account of Recent Researches into the Function of Emotional Excitement, Appleton, New York, 1915).

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 four 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 put forward the Dry Mouth Hypothesis, stating that people get thirsty because their mouth gets dry. He did an experiment on two dogs. He cut their throats and inserted a small tube. Any water swallowed would go through their mouths and out by the tube, never reaching the stomach. He found out that these dogs would lap up the same amount of water as control dogs.

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

Books
His books include The wisdom of the Body, Traumatic Shock, The Way Of An Investigator : A Scientist's Experiences In Medical Research, Autonomic Neuro-Effector Systems, An Account Of Recent Researches Into The Function Of Bodily Changes In Pain, Hunger, Fear, And Rage and A Laboratory Course In Physiology.

External links and references

 * 6th APS President at the American 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)
 * Walter Bradford Cannon: Reflections on the Man and His Contributions, International Journal of Stress Management, Vol. 1, No. 2, 1994
 * Marian Cannon Schlesinger, Snatched from oblivion: A Cambridge memoir, Boston: Little, Brown and Company, 1979

Walter Cannon & Walter Cannon