Walter Bradford Cannon
- Bernard-Cannon homeostasis
- Cannon's law
- Cannon's point
- Cannon's reflex
- Cannon's waves
- Cannon-Bard theory
- Cannon-Dougherty reflex
Biography of Walter Bradford Cannon
Walter Bradford Cannon was born in Prairie du Chien, Wisconsin. It was here, at Fort Crawford, William Beaumont (1785-1853) in 1829 to 1831 had carried out some of his studies of gastric secretion on Alexis St. Martin.
He was the first of four children born to Colbert Hanchett Cannon (1846-1915), a railroad official, and Sarah Wilma Denio, a high school teacher. Both parents belonged to pioneering families that had pushed westward from Massachusetts early in the nineteenth century to settle eventually in the upper Mississippi valley.
In science I believe
From his early years he showed a great interest in the biological sciences. As a youngster, he read about the debates between traditionalists and Darwinists, especially those involving William Wilberforce, bishop of Oxford, and Thomas Huxley. During his high school years the perceived conflict between science and religion so affected him that he eventually announced that he no longer believed in the ideals of the Calvinist church, the faith of his family. He was subsequently referred to a minister, about whom he later remarked, “The clergyman in the church took precisely the wrong course in dealing with my difficulties; he wanted to know what right I had, as a mere youth, to set up my opinion against the opinion of great scholars who supported the church's doctrines. This appeal to authority did not impress me at all, because I knew that there were great scholars in the opposition. Furthermore, I had the feeling that I was entitled to my independent judgment."
Cannon attended primary and secondary school in Wisconsin and Minnesota. By the end of his high school career, he had distinguished himself academically, and was prepared to attend Harvard College in 1892. Because of his interest in the biological sciences, he decided to pursue a preparatory course for medical school. He graduated summa cum laude in 1896 and entered Harvard Medical School. As an undergraduate he was influenced by the biologist Charles Benedict Davenport (1866-1944) and the zoologist George Howard Parker (1864-1954).
Illuminating stomachs at Harvard
Already as a first year student in 1896 Cannon began working in Henry Pickering Bowditch's (1840-1921) laboratory. Bowditch put him to work using the newly discovered Roentgen rays to explore the mechanism of swallowing and the motility of the stomach. These studies resulted in the introduction of the bismuth meal for improving the contrast in radiological investigations of the gastro-intestinal tract. At a meeting of the American Physiological Society, Cannon demonstrated the movement of a pellet through the gullet of a goose. The physiology of digestion was a topic that occupied him for the next decade and a half and launched his career as a physiologist. In 1900 he received his medical degree and became a member of the American Physiological Society.
Following graduation he was an instructor in the Department of Physiology at Harvard from 1900 to 1902, when he was promoted to assistant professor. In 1906 he succeeded Bowditch as George Higginson Professor and chairman of the department, a position he retained until 1942. He headed one of the most active departments in the country, where students from around the world were trained.
In 1912 he demonstrated that the pangs of hunger are due to cramp-like contractions of the stomach. His pioneering reoentgenographic studies of movements of the digestive tract had attracted wide attention when he terminated his investigations in 1912.
Cannon observed that the movements of the stomach and intestines ceased whenever his animals became excited. This aroused his interest in the autonomic nervous system. Over a period of more than twenty years, from 1911, Cannon and his many students published a long list of papers in which was set forth evidence that under conditions of physiological stress the sympathetic system and its constituent part, the adrenal medulla, act to produce visceral adjustments which are nicely adapted to the preservation of the individual.
A Cannon goes to war
In World War I, Cannon served with British Military Service as a commissioned Lieutenant Colonel in the Medical Corps 1917-1919. He crossed the Atlantic with Harvey Williams Cushing (1869-1939) and Robert Bayley Osgood (1873-1956). At various laboratories and field hospitals in England and France, he worked as “laboratory hermit” and “field investigator” on the problems of wound shock, studying its complex chain of phenomena. One of his important colleagues was William Maddock Bayliss (1860-1924) with whom he collaborated in the development of the gum-saline technique of replacing blood volume.
His investigations on hemorrhagic and traumatic shock during World War I were summarized in Traumatic Shock (1923). In it he postulated that traumatic shock was caused by blood being drained into the dilated capillary region, a phenomenon for which he coined the term exemia. The treatment of shock, he argued, should concentrate on reinstating normal circulation. Also well documented is his research on the sympathetic nervous. For his war efforts he was awarded the Distinguished Service Medal.
Cannon is particularly remembered for his pioneering contributions to the knowledge of the emergency functions of the sympathetic nervous system and on homeostasis. His early results on this were published in Bodily Changes in Pain, Hunger, Fear and Rage (1915) and in The Wisdom of the Body (1932). The validity of the emergency theory of the sympatho-adrenal system was dramatically confirmed in 1929 when Cannon and four collaborators showed that cats from which both chains of ganglia had been removed are capable of normal life under uniformly serene circumstances, but exhibit deficiencies when exposed to conditions of physiological stress.
From the use of the denervated heart as an indicator of medulliadrenal secretion came the discovery that sympathin is produced in the normal animal. Sympathin is an adrenaline-like substance that is liberated at the tips of certain nerve cells. This disclosure led Cannon into the territory of the chemical mediation of nerve impulses where he became a pioneer. He wrote two monographs on this with Arturo Stearns Rosenblueth (1900-1970). He also worked on methods of blood storage
A "congressman" and a public figure
When the XIII International Physiological Congress was held at Boston in 1929, Cannon was host in charge of local arrangements. In the 1930s he was the American representative to the International Committee that organized the congresses. At the fiftieth anniversary of the Society in 1938, Cannon presented a tribute to his teacher, Bowditch, at the celebratory banquet. He is commemorated by the Society through the Walter B. Cannon Memorial Lecture, a plenary lecture given at the spring meeting of the Society and sponsored by the Grass Foundation.
At this point in his career, Cannon also became a major public and political figure. He had earlier been involved in defending animal experimentation in medical research against the attacks of antivivisectionists, and he now emerged as a strong defender of the scientific community against the assault of fascist governments. He became a national leader of such organizations as the Medical Bureau to Aid Spanish Democracy and, a few years later, the American–Soviet Medical Society. Cannon was neither naive nor an apologist for the Communist Party, but an extraordinarily open-minded man who spoke out on the causes of his day with the courage of his convictions.
To the rescue of Pavlov
Cannon’s inquiries into the physiology of the digestive system inspired his interest in the work of the internationally acclaimed physiologist, Ivan Petrovich Pavlov (1849-1936). In 1920 Cannon discovered that Pavlov was facing starvation in St. Petersburg due to the famine created by the chaos of the Russian Civil War. Cannon worked to get assistance to Pavlov and other Russian scientists. Thus Cannon and Pavlov began a corresponding relationship and friendship, which continued until Pavlov’s death in 1936. They first met at the Carnegie Nutrition Laboratory, Boston, on June 26, 1923.
Cannon developed the concept of homeostasis and 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.
Walter Bradford Cannon was married to Cornelia James Cannon, a best-selling author. Although not mountaineers, during their honeymoon they 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 (1907-2005), a military plastic surgeon and radiation researcher. His daughter is Marian Cannon Schlesinger, a painter and author living in Cambridge, Massachusetts.
- «I have all the money I want. My wife gives me ten dollars a month and with that I pay my carfare, buy my lunches and get my hair cut.»
The Way of an Investigator, «Many Happy Returns»
«The only reasonable attitude for the seeker after truth is that of true humility.»
The Way of an Investigator, Fitness for the Enterprise»
«These changes - the more rapid pulse, the deeper breathing, the increase of sugar in the blood, the secretion from the adrenal glands - were very diverse and seemed unrelated. Then, one wakeful night, after a considerable collection of these changes had been disclosed, the idea flashed through my mind, that they could be nicely integrated if conceived as bodily preparations for supreme effort in flight or in fighting.»
The Way of an Investigator, ”The Role of Hunches”.
«There are still among us benighted persons who would sympathize with the member of the House of Commons who, commenting on the extravagance of the London School Board, declared: "Physiology, besides being costly and useless, is an immodest subject. When the Author of the Universe hid the liver of man out of sight He did not want frail human creatures to see how He had done it." Indeed, when my academic title was advanced to that of a full professorship, a sensitive Cambridge lady, who had learned somehow that I was working on the activities of the digestive tract, was heard to remark, "I do hope that now he will give up his disgusting researches on the stomach."
The Way of an Investigator, ”Making Science Understandable»
«While patience and tenacity in research are admirable, a situation may arise in which persistence is unwarranted. Then these admirable qualities may become mere obstinacy.»
The Way of an Investigator, «Fitness for the Enterprise»
«The investigator may be made to dwell in a garret, he may be forced to live on crusts and wear dilapidated clothes, he may be deprived of social recognition, but if he has time, he can steadfastly devote himself to research. Take away his free time and he is utterly destroyed as a contributor of knowledge. «
The Way of an Investigator, «Fitness for the Enterprise»
«Investigators are commonly said to be engaged in a search for the truth. I think they themselves would usually state their aims less pretentiously. What the experimenter is really trying to do is to learn whether facts can be established which will be recognized as facts by others and which will support some theory that in imagination he has projected. But he must bed ingenuously honest. He must face facts as they arise in the course of experimental procedure, whether they are favorable to his idea or not. In doing this he must be ready to surrender his theory at any time if the facts are adverse to it.»
The Way of an Investigator, «Fitness for the Enterprise»
«The near point of clear vision recedes until with unaided eyes the elderly person, holding the page at arm’s length in order to see it clearly, is bothered by the indistinctness due to distance; caught between these troubles of too near and too far, he moves the page back and forth - as Holmes put it, he has reached the «trombone age»!
The Way of an Investigator, «The fruitful years»
«My first article of belief is based on the observation, almost universally confirmed in present knowledge, that what happens in our bodies is directed toward a useful end.»
The Way of an Investigator, «Some Working Principles»
"fight or fright"
Cannon coined this term in 1915 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.
"Dr. Cannon's success is due to the fact that his search for the truth, and particularly physiological truth, is akin to a religious issue which he pursues with an almost evangelical zeal. It is his faith in the importance, I might even say righteousness, of physiological investigation which seems to give him the tremendous energy which his work shows and which he manages to instil into the students who are working with him. This zeal is for the establishment of truth in general, but it is also very markedly for the establishment of physiological truth in particular."
Said by Arthur Redfield of Cannon in 1931.