[202]. The Work of the Digestive Glands (English Translation), London, 02.
[203]. For a summary of Cannon’s work, see his article, Recent Advances in the Physiology of the Digestive Organs Bearing on Medicine and Surgery, The Medical Journal of Medical Sciences, 1906, New Series, Vol. CXXXI, pp. 563-578.
[204]. American Journal of Medical Sciences, 1906, p. 566. See also “The Influence of Emotional States on the Functions of the Alimentary Canal,” by the same writer (ibid., April, 1909) for an interesting résumé of the subject.
[205]. American Journal of the Medical Sciences, April, 1909.
[206]. Cannon and de la Paz: American Journal of Physiology, April 1, 1911.
[207]. Cannon, Shohl, and Wright, Ibid., December 1, 1911.
[208]. These effects of adrenalin suggest that the secretion may take some part in pathological anxiety states.
[209]. Pathologie des Emotions, 1892.
The influence of emotion on the muscular system need hardly be more than referred to. Tremor, twitchings, particularly of the facial muscles, and other involuntary movements, as well as modifications of the tonus of the muscles, are common effects. All sorts of disturbances occur, ranging from increase of excitability to paralysis. Everyone knows that under the influence of powerful emotion, whether of joy, anger, or fear, there is discharged an increase of energy to the muscles, sometimes of an intensity which enables an individual to
[210]. The Integrative Action of the Nervous System, p. 266.