the function of the sympathetic nervous system of adapting the organisms of vertebrates and man to changing (in particular, extreme) environmental conditions by changing the level of metabolism of all organs and tissues. An experimentally substantiated theory of adaptotrophic function was developed by the Soviet physiologist L. A. Orbeli and his collaborators during the 1920’s. According to this theory, the so-called functional nerves that evoke a specific activity of a tissue or organ—for example, the motor nerves of skeletal muscles—regulate the metabolic processes on which this activity is based, while the sympathetic nerves regulate the level of metabolism, the excitability, and the efficiency of tissues and organs. It was shown that the efficiency of a muscle fatigued by rhythmic stimulation is restored during stimulation of the sympathetic nerve that innervates this muscle. The sympathetic nervous system also affects the condition of all parts of the central nervous system and sense organs; in particular, it changes unconditioned and conditioned reflex activity. The adaptotrophic function is aimed at stabilizing functional properties: organs deprived of their sympathetic innervation do not lose their inherent functions, but in the case of increased demands (owing to changed conditions or intensive work) they cannot reorganize their metabolic level and vital activity to the same extent as normal organs. The adaptotrophic function is brought about by means of physicochemical and biochemical changes occurring under the influence of impulses traveling over the sympathetic nerves directly to the organs or by means of adrenaline, the mediator of the sympathetic nervous system.
REFERENCEOrbeli, L. A. Izbr. trudy, vol. 2. Moscow, 1962.
A. V. TONKIKH