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Physiological basis of labor
Work is necessary for optimal biological processes in the body, therefore has a great impact on health. Physical work is characterized by the weight and is associated with the implementation of static and dynamic work, and is associated with mental tension in the background static. The basis of physical and mental labor are the same central mechanisms. Physical labor is different high energy consumption, oxygen consumption, the rapid development of fatigue and relatively low productivity.
Static work more tiring than dynamic. When dynamic work processes through alternation of contraction and relaxation of muscles past they rest. Twitch skeletal muscle at the same time act as micropumps, facilitating blood circulation and serving as a "peripheral heart". With static muscle tension work without interruptions, vessels are constantly squeezed and normal blood circulation difficult. This leads to stagnation of blood accumulation in the muscles in the body and the products of incomplete oxidation.
Mental work is among the very time-consuming and stressful.
First of all need a clear and precise work of the brain: attention and memory, which most people consider as the main key to success in intellectual work. Attention has undulation due to natural physiological reasons - the periodic increase in the excitability of the brain is replaced by decreasing its activity and is associated with the emergence and maintenance of a persistent focus of excitation in one (or more) well-defined centers of the brain. Memory associated with the preservation of traces of persistent excitation (or internal inhibition) in various centers of the cerebral cortex of the brain.
With increasing severity of physical labor and intellectual labor intensity increases oxygen consumption. There is a limit on the maximum amount of oxygen that is able to consume the people - so-called oxygen ceiling. Usually it is not more than 4.3 l / min. During the execution of very hard work oxygen delivery to the body reaches its limit, but the need for it becomes more and more is not satisfied in the process. At this point in the body there is a state of oxygen deficiency - hypoxia, which is damaging factor. Violated intracellular oxidative processes and produces toxic substances - oxygen free radicals, toxic body. If the hard physical and mental work continues for a long time or a person not accustomed to great physical or mental stress, his respiratory and cardiovascular systems work poorly provide muscle and brain cells. In the body, there are mechanisms to prevent the development of this dangerous condition. A decrease in efficiency, develops fatigue. However, if the operation does not have time to recover before the next working day, fatigue develops, accompanied by chronic hypoxia, impaired nervous activity, cardiovascular and other systems.
prevention of fatigue
Fatigue - a physiological condition of the body resulting from excessive activity and manifests itself in reduced efficiency. Fatigue may occur in any kind of activity - and mental, and physical work.
Mental fatigue is characterized by a decrease in the productivity of intellectual labor, in violation of attention, slowing of thinking, sleep disorders. Physical fatigue manifested muscle dysfunction: a decrease in strength, speed, accuracy, consistency and rhythmic movements.
Performance may be reduced not only by the work done, but because of illness or unusual conditions. In these cases, reduction of efficiency is the result of violations of the functional state of the organism.
The rapidity of fatigue depends on the specifics of labor: it occurs much sooner in performing the work, accompanied by monotonous posture, muscle tension; less tedious rhythmic movements. Many people in the period of emotional stress for a long time not there are signs of tiredness and fatigue. Fatigue associated with reduced capacity for work, which is being restored as a result of recreation.
Tired of people working less accurately by allowing small first, and then the serious errors.
Lack of time or vacation work overload for a long time often lead to chronic fatigue or exhaustion, which can cause neuroses and diseases of the cardiovascular system.
For the prevention of fatigue must be considered two phases of efficiency: I - excitatory associated with restlessness, distraction of attention; II - brake when there is lethargy, loss of vitality.
Efficiency and quality of work during the excitatory phase of fatigue may be high, but this is achieved through willpower and mental stress. There is a subjective feeling of fatigue, but the work should be continued until the onset of phase II of fatigue.
If signs of central inhibition of brain structures attempts to overcome it and continue to work can cause fatigue, so offensive inhibitory phase necessitates rest.
Important means of combating fatigue is an efficient mode of work and leisure or business at certain times of the day short breaks that are organized based on the nature of the labor process. Complete rest is not idleness, and should be alternated with physical activity and a change in activity.
An effective means of long-term preservation of efficiency during the working day is a clear rhythm work.
Work performed rhythmically, about 20% less tiring than spasmodic work the same severity.
In conducting activities to prevent fatigue important place should be allocated eliminate unnecessary movements, the rational organization of the workplace, not only saves the movement, but also to work in a normal posture, eliminating static muscle tension.
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