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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



in physiology, the suppression of activity in an organ or tissue in response to the excessively high frequency or intensity of an applied stimulus. The pessimum was first described in 1886 by N. E. Vvedenskii. While investigating impulse conduction in a neuromuscular specimen from a frog, he discovered that the intensification of tetanus, or continuous muscle contraction, that is produced by a gradual increase in the frequency or strength of a muscular stimulus is suddenly replaced by complete relaxation and inhibition of the muscle’s activity as the applied stimulus is accelerated or intensified (seeOPTIMUM).

Vvedenskii viewed the pessimum phenomenon in terms of his theory of parabiosis. According to this theory, the efficiency of nerve endings that transmit impulses to muscles drops sharply after an excitatory wave passes. Restoration of efficiency requires some time; for example, in a neuromuscular specimen that uses the gastrocnemius muscle of a frog, the refractory period is 0.02-0.03 sec. The time determines the functional capacity of nerve endings, that is, their lability. If the interval between stimuli is shorter than the required refractory period, that is, if it exceeds the requirements set by the lability of the nerve endings, a special type of nontransmissible excitation, called parabiosis, arises in the nerve endings. Parabiosis blocks the conduction of nerve impulses to the muscle and thus inhibits the muscle’s activity; this mechanism is a protection against overfatigue. The pessimum phenomenon is reversible: a decrease in the intensity of stimulation restores muscle contraction. A number of organs and tissues have been shown to exhibit a pessimum. Many investigators believe that the pessimum is the underlying mechanism in the nervous system’s regulation of bodily activity.


Vvedenskii, N. E. “O sootnosheniiakh mezhdu razdrazheniem i vozbuzhdeniem pri tetanuse.” Poln. sobr. soch., vol. 2. Leningrad, 1951.
Vvedenskii, N. E. “Vozbuzhdenie, tormozhenie i narkoz.” Poln. sobr. soch., vol. 4. Leningrad, 1953.
Ukhtomskii, A. A. “Vozbuzhdenie, utomlenie, tormozhenie.” Sobr. soch., vol. 2. Leningrad, 1951.
Ukhtomskii, A. A. “Iz istorii ucheniia o nervnom tormozhenii.” Sobr. soch., vol. 2. Leningrad, 1951.
Beritov, I. S. Obshchaia fiziologiia myshechnoi i nervnoi sistemy, 3rd ed., vol. 1. Moscow, 1959.
Fiziologiia cheloveka. Moscow, 1972.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
De acuerdo con la praxis del Santo Oficio, desde el punto de vista objetivo, los actos constitutivos de crimen pessimum no eran los limitados a actos venereos completos, sino que tambien se incluian los denominados <<actos imperfectos>>, como miradas, besos, abrazos, etc., fruto de una intencion libidinosa.
Un clerigo acusado de crimem pessimum en relacion a uno de los dos ultimos tipos de actos, tendria que probar que no habia intencion libidinosa o que habia justa causa para hacerlos (36).
En consecuencia, si el sujeto pasivo del delito era una chica de trece anos o un chico de quince, no estabamos ante un crimen pessimum, y por ello no quedaba reservado al Santo Oficio.
Segun el articulo 72 de Crimen sollicitationis, las penas establecidas para el crimen pessimum eran las mismas que las previstas por el art.
Como se ve, el clerigo culpable de crimen pessimum podia ser castigado con las penas mas graves.
72 declaraba que a lo establecido para el crimen pessimum era aplicable mutatis mutandis lo establecido en la Instruccion para el delito de solicitacion.
Como puede observarse, no habia una unica solucion para todos y cada uno de los casos de solicitacion o crimen pessimum. Para llegar a una decision justa, habia que sopesar todos los elementos para que hicieran posible un fallo que garantizara la justicia de todas las partes implicadas.