THE PHYSIOLOGY OF SWEAT GLANDS

Time relations were studied of the sweating responses of men during vigorous exercise and recovery with corresponding changes of temperature in the rectum, oesophagus, tympanic membrane, femoral and saphenous veins, gastrocnemius muscle and at 7 points on the skin. The results suggest that sweating was regulated in these exercise experiments by reflex effects originating from thermal receptors in the veins which drain warm blood from the working muscles, summated with reflexes from cutaneous thermal receptors, and with alterations of activity if the hypothalamic center produced directly by temperature changes in the center. Mechanoreceptors in muscles and joints probably do not participate in the regulation of sweating in exercise. d- Aldostrone, administered to normal men by continuous intravenous infusion, was found not to alter the NaCl concentration of their sweat during 5 to 7-hour periods of work in the heat 45 C.. Continuous infusion of d-aldosterone at 0. 1 mghr into one brachial artery did not alter the Na or Cl concentration of sweat being secreted by the infused forearm.