Cannon

CANNON Walter Bradford (Walter Bradford Cannon, b. 1871), American physiologist, professor at Harvard University in Boston (USA). C. was the first to introduce into physiology the method of studying the digestive tract and the movement of food through it by means of X-ray illumination after adding bismuth salts to food (1897). C. studied in detail the 'law of the intestine' discovered by Bayliss. From 1913, C. published with his students a series of studies on the role of adrenaline in the body; the results of these works are combined in the book: 'Bodily changes in pain, fear, hunger and rage' (3rd ed., N.Y.-L., 1923; Russian ed.-'Physiology of emotions', L., 1927). In this book, C. proves that during strong emotions and pain, there occurs a reflex excitation of the splanchnic nerves, leading to the secretion of adrenaline by the adrenal glands; adrenaline, in turn, causes all those physiological changes that characterize the states of pain, fear, and rage: cessation of intestinal activity, restoration of excitability in fatigued muscles, acceleration of blood clotting, increase in sugar content in the blood, and increased frequency of respiration. In the same book, Cannon's observations on the localization and mechanism of the origin of the feeling of hunger are presented, which he considers to be connected with periodic non-digestive contractions of the stomach. C.'s works are distinguished by impeccable methodology. A weak point in C.'s theories is their extreme schematization, failure to take into account the significance of other physiological factors that play a role in the mechanism of the physiological manifestations of emotional states besides the reflex secretion of adrenaline, and the philosophically inconsistent application of the data obtained for the interpretation of a number of social phenomena (e.g., 'military valor'). Cannon's conclusions are disputed by some authors. The majority of Cannon's works were published in the 'American journal of physiology'. Besides numerous experimental works published in various American journals and the aforementioned monograph, Cannon is the author of a major work: 'The mechanical factors of digestion' (L., 1911).