From Big Medical Encyclopedia

EXHAUSTION — the temporary reduction of functionality of an organism (physiological system, body) caused by hard or long work and which is expressed in decrease in working capacity. At. it can be shown by decrease in quantity and quality of the performed work, and also deterioration in regulation of functions of an organism. Such terms as «fatigue» correspond to the concept «exhaustion» (property of a physiological object to be subject At.) and «fatigue» (the subjective characteristic — feeling At.).

Fiziol. mechanisms U. originally connected with a lack of the humoral environment it is long the working body (as a rule, muscles) oxygen and vysokoergiche-sky connections (see), and also accumulation of products of exchange — lactic acid (see) and other substances. On this basis there were theories of «suffocation», «exhaustion», «contamination» (humoral lokalisti-cheskaya the theory At.). The facts proving these theories were received in experiments on the muscles isolated from c. N of page. In the Soviet physiology of work the ideas of the neurogenic nature of exhaustion stated in researches and I. M. Sechenov's generalizations, I. P. Pavlova, H are dominating. E. Vvedensky, A. A. Ukhtomsky, L. A. Orbeli, G1. K. Anokhina. Are concretized by their pupils and followers connected with At. various parties of work of a nervous system and other bodies: exhaustion of energy resources, trophic influences, lack of coordination, change of excitability of functional units, participation of process of braking, etc.

During purposeful, napr, labor, activity inevitably there is a consumption of power connections. Continuous consumption of the functional reserves providing implementation of vigorous activity is limited by a certain framework. This restriction is called by I. P. Pavlov a limit of working capacity. The limit of working capacity determines the level of the maximum efficiency of the person. The limit of functional reserves can be spent at short-term, but considerable loading when great nervous and physical efforts are required, during moderate, but long work without sufficient breaks for rest and other conditions for maintenance.

During hard work many vital constants of a homeostasis are broken (see). There are considerable changes in action of the heart, vessels, respiratory system and other bodies. Process of recovery of the vital constants of an organism happens at the expense of the mutually promoting relations between various functional systems of an organism (see. Functional systems).

The leading role of the central nervous factors in the mechanism muscular At. the person and, especially, ideas of preferential fatigue of a cortical link and purely regulatory restriction of work of executive bodies is pulled together fiziol. mechanisms U. at muscular and cerebration. Therefore the community of the approaches to interpretation of a number of questions connected with problem U is justified., with the phenomena of overfatigue, with ways of diagnosis At. and stimulations of working capacity at both forms of activity.

In the evolutionary plan At. formed as adaptive reaction. The person has an exhaustion — protective biol. reaction (see. Defense reactions of an organism), protecting an organism from the expressed decrease in resources and at the same time serving as a reference point at a training (see).

Loudspeaker U. in different conditions it is various that is defined both by character of loading, and environmental factors. Adverse production factors, napr, work in hot workshops (see), vibration (see), noise (see), significantly accelerate development At. Huge influence on efficiency of the person and his fatigue renders the complex of factors determined by conditions of the social environment.

(Both physical, and intellectual) overfatigue — a complex of the functional disturbances in an organism caused excessive single At can be result of the irrational organization of work. or the progressing accumulation At., remaining throughout a long time (weeks, months). If At. — normal fiziol. the phenomenon, that overfatigue should be considered as a borderline, prepatologichesky case. Development of the neurotic process connected with peculiar «sshibky» is the cornerstone of it (according to I. P. Pavlov) at persistent further work against the background of expressed At. The rational organization of rest (see) and the subsequent restriction of loadings in these cases are obligatory, otherwise overfatigue can pass into a typical neurotic syndrome (see the Neurasthenia).

Diagnosis At. is of great importance since forms the basis for implementation of measures for rationalization of work and provides control of their efficiency. The criteria forming a basis of diagnosis At., also objective data are subjective (feeling of fatigue) (the indicators of reduced working capacity and other shifts in an organism accompanying At.) - Reduced working capacity is reflected by three groups of indicators — quantitative, qualitative and diskoordi-natorny. Quantitative decrease in working capacity can be expressed in reduction of productivity of work for a unit of time or in reduction of yield values of work, to-rye are reached at the maximum tension. First of all it is necessary to be based on indicators of production activity. However efficiency of work throughout change depends on many collateral factors, and in many professions difficult gives in to the exact account in comparable units. High-quality decrease in working capacity can be diagnosed on indicators of the performed work (the accounting of marriage, quality of products) and by results of special tests (definition of number of mistakes during the work with proof tables, assessment of accuracy of movements by means of kinestizimetr and koordini-meters, etc.) * At intellectual At. the becoming frequent periodic derivations of attention called «blocks» can affect quality of work. To catch this sign At. it is possible only with the help it is long the applied tests of attention. Diskoordination of working processes — the most important criterion of decrease in working capacity at At., allowing to watch its development without separation investigated from work and often finding At. even before decrease in quantitative and qualitative characteristics. Confirm dis-coordination as operational performance (disturbances of a working stereotype, napr, changes of duration of phases of labor movements, variability of time of their performance), and physiological (a mismatch of various functions, decrease in efficiency fiziol. expenses). Changes of a functional condition of various bodies and systems, in particular are noted by c. N of page and analyzers (according to time of reaction, critical frequency of merge of light flashings and so forth).

Measures of fight with At. shall be directed not to elimination of it fiziol. the phenomenon having protective character, and on the prevention of overfatigue and acceleration of recovery processes. For this purpose carry out the measures leading to steady and long increase in working capacity (training), and measures, directed to temporary stimulation of working capacity. A training (see) provides the minimum expenditure fiziol. reserves at the set intensity, consolidation of skills, the correct and optimum distribution of micro pauses and breaks in work.

To the measures of temporary stimulation of working capacity distancing At. thanks to involvement of difficult corticosubcortical mechanisms, belong emotional and afferent stimulation — improvement of mood, increase in interest in work, use of so-called functional music and gymnastics, change of operations during the day, etc.

Efficient means of acceleration of maintenance is the effect of active recreation opened by I. M. Sechenov (see. Muscular work). Among mechanisms of this phenomenon the leading role belongs to the induction relations between nerve centers: involvement of the new centers deepens braking earlier tired that accelerates their recovery. To one of ways of implementation of sechenovsky effect serve a sports pause as a component of production gymnastics (see Gymnastics? production gymnastics). Great value in prevention At. and increase in working capacity rationalization of work-rest schedules, implementation of ergonomic requirements to the organization of jobs and to improvement of the production equipment (see Ergonomics) have, improvement of working conditions and life of working.

Features of exhaustion at children are defined anatomo-physiologists-cheskimi by features of activity of c. N of page of the child.

At chest age a superactivity during wakefulness quickly results in dominance of braking. It extends on bark of big hemispheres and a nek-eye to other departments of a brain. As a result the child falls asleep before in his organism the changes characteristic of

U. U of children of 2 — 3 years of life manage to appear At. already can develop more clearly though the child cannot correctly estimate feeling of fatigue and the need for rest. However in behavior there occur natural changes, to-rye are connected with the decrease in functional activity of cortical departments of a brain resulting At, E.g.? there are earlier not observed mistakes in answers to questions, coordination of small movements changes, concentration of attention decreases, the child distracts from in what he is engaged, the periods of continuous activity decrease. Often adults regard these actions as prank, without understanding an actual reason of such state. The tired child can come on a nek-swarm time to excited state. On this background irritability is shown, between children there can be conflicts. At overfatigue these behavior disorders become deeper, appetite decreases, the sleep is interrupted.

Overfatigue is expressed often as manifestations of obstinacy, negativism, aggressive actions.

Functional activity

of of N of page at children of early age is rather small and though it for the first three years of life increases, children of this age period easily and quickly get tired. The reasons At. are various, but one of main is discrepancy of duration of wakefulness to a limit of operability of their nervous system. Soviet scientific H. M. Shchelovanov and H. JI. Figurin proved the maximum time spans of continuous wakefulness in the first three years of life. Systematic increase in duration of wakefulness without age leads to overfatigue and even to formation of neurotic states.

Essential origins At. at children is also hron. a sleep debt, the wrong organization of wakefulness (lack of selection of toys according to age, alternations of quiet games with mobile etc.), difficulty of the tasks shown to children, long viewing of programs on TV, long reading etc. Restriction of a physical activity of children of early age leads to an overstrain of c. the N of page and

preschool age a nervous system becomes gradually steadier against U. V development; the child of 3 — 4 years can be more long time in an active state. Operability of nervous cells increases with age, and the child

of 5 — 6 years gets tired not so quickly as the child of younger age. At. at this age the hl is shown. obr. in dispersion of attention, decrease in interest in work, failure from it.

At younger school students of a behavior disorder can be expressed poorly. Them it is possible to force to be engaged it is long. But at At. the number of mistakes accrues, and overfatigue is shown in a sleep disorder, appetite, leads to functional shifts. They have two peaks of working capacity: the first — from 8

to 11 hours of morning, the second — between the 16 and 18 hour. Then intensive recession as a result of which evening lessons of school students can lead to overfatigue follows. Often at children of younger school age overfatigue results from overloads — combination of the school, often special, with music etc.

Prevention At. at children comes down, first of all, to providing all conditions necessary for harmonious development and preservation of health. The mode corresponding to age, correctly organized wakefulness, broad inclusion in the mode of walks and a sufficient physical activity is especially important. Positive emotions, and also unity of educational approaches are very important. Decrease in fatigue is promoted by all factors improving the general state of health.

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