A review of psychoendocrine research on the sympathetic-adrenal medullary system.

J.HE SYMPATHETIC-ADRENAL medullary system was the first endocrine system to be studied experimentally with regard to the possible participation of emotional factors in its regulation. The concept that the adrenal gland might be susceptible to emotional stimuli was developed by Walter Cannon with characteristic logic. He reasoned that: (1) it was known that the adrenal medulla is linked to the sympathetic nervous system; (2) many physiological changes known to accompany emotional arousal, such as dilation of the pupils, fast pulse, piloerection, and inhibition of gastrointestinal function, etc., are all signs of increased sympathetic nervous system activity; and (3) therefore, as he put it, "Do not the adrenal glands share in this widespread subjugation of the viscera to sympathetic control?" Cannon had been perhaps predisposed to think along these c-<ginal lines as a result of the deep impussion made upon him, in his early experience as an investigator, by noting the marked sensitivity of the stomach and intestines to psychological stimuli.