SYMPATHOADRENAL SYSTEM [lat. (systema nervorum) of sympathicum a sympathetic nervous system + adrenalis epinephral] — one of systems of regulation of a homeostasis. The village of the village consists of a nervous link (see. Autonomic nervous system ) and hormonal, including the hormones synthesized by marrow adrenal glands (see), and paragangliya (see) — adrenaline (see), noradrenaline (see) and dopamine (see. Catecholamines ).
Association of a sympathetic nervous system and chromaffin cells of marrow of adrenal glands and paragangliyev in a whole is justified with morfol. and fiziol. positions. Chromaffin cells paragangliyev and adrenal glands are innervated by cholinergic fibers of cells of side horns spinal cord (see) owing to what cosecreted by them catecholamines, preferential adrenaline, represent a humoral equivalent of the postganglionic nerve fibrils producing topical noradrenaline. At rather strong influences of S. of page reacts it is generalized, two links, causing emergence in an organism of the shifts, known, according to U. Kennon as reaction of fight and flight. However at less intensive influences perhaps preferential involvement in response of this or that link of S. of page or even separate parts of its nervous link. Distinction of excitation thresholds of different postganglionic structures can be the cause of it. Bystry reaction of S. of page to change of any parameter internal environment of an organism (see) and bystry emergence of effects of activation of S. of page provides a possibility of constant «fine tuning» of internal environment of an organism according to requirements of the moment. Important feature of S. of page is change of its activity even before emergence of real disturbances homeostasis (see) that weakens their weight for an organism. It is caused by existence of various, including cortical and hypothalamic, afferent entrances to S. of page at the level of a brain trunk (see. Brain ). Set of reactions of an organism to changes of surrounding or internal environment (or) irrespective of specifics of the operating factor in many respects is defined only on threat of such changes by a combination of straight lines and mediated through other systems (hl. obr. through endocrine and cardiovascular systems) effects of catecholamines.
See also Neurohumoral regulation .
Bibliography: Orbeli L. A. Chosen works, t. 1 — 5, M. — L., 1961 — 1968; Smitten N. A. Sympathoadrenal system in filo-and ontogenesis of vertebrata, M., 1972, bibliogr.; Cannon W. Century of The wisdom of the body, N. Y., 1939; Landsberg L. Catecholamines and the sympathoadrenal system, in book: The year in endocrinol., 1975 — 1976, ed. by S. H. Ingbar, p. 177, N. Y. — L., 1976, bibliogr.
V. I. Kandror.