magnetic field (biological effect)

From Big Medical Encyclopedia

MAGNETIC FIELD — a part of space where power impact on moving electric charges is implemented; special case of the electromagnetic field. Though interest in influence of L. S. on a human body arose in an extreme antiquity, biol, action of L. S. began to be studied intensively from 60th 20 century in connection with development of bioastronautics. Influence of L. S. on processes of growth, development and a structure of viruses, microorganisms, plants and animals is established. The opinion on a role of natural L. S. as one of factors of evolution is expressed. Value of L. S. for orientation biol, systems in time and space is noted. It is necessary to consider dependence of effect of intensity (tension) of L. S., its gradient (heterogeneous L. S. works stronger), tensions (orientation of birds and fishes at distant migrations can be carried out on L. S. of Earth), exposures and localizations of influence. Upon transition to variable L. S. it is necessary to consider in addition such biotropny parameters as frequency and a pulse shape of L. S. It is shown that variations of biotropny parameters strengthen biol, effect of action of L. S. At the higher organisms nervous, endocrine, cardiovascular systems and system of blood are considered the most sensitive to L. S., though other systems of an organism are not indifferent to action of L. S. Having the high getting property, L. S. can directly influence various structures of a brain, and the hypothalamus is most subject to action of L. S. The m of the item changes processes of perception, storage and reproduction of information a brain. Both nervous, and glial cells react to L. S. In addition to such direct influence, also reflex influence of L. S. on a nervous system is observed. Electronic and microscopic and biochemical researches showed that all intracellular organellas react to L. S. and is most expressed — mitochondrions. Under the influence of L. S. changes as well permeability biol, membranes. Primary physical. - the chemical mechanism biol, actions of L. S. includes change of orientation of macromolecules, hydration of ions, targeting of EMF of electromagnetic induction etc.

The practical application of results of a research of mechanisms biol, actions of L. S. is connected with magnetotherapy (see) — anesthetic, antiinflammatory and antiedematous action of L. S., with magnetodiagnosis — contactless registration of L. S. of heart and brain about a gigabyte is noted. assessment of nature of action of L. S. on production, clarification of the ecological importance of L. S., and also use of L. S. at a research biol, objects.

biol, actions of L. S. the great value what carrying out the international symposiums on biol, to action of L. S. testifies to is attached to studying (1961, 1963 and 1966, Chicago, the USA). In 1966 in the USSR the first All-Union meeting on problems biol was held, actions of L. S., and since 1970 in the different cities of the USSR annually take place symposiums on use of L. S. in biology and medicine.

See also Magnetism , Electromagnetic field .

Bibliography: Influence of magnetic fields on biological objects, under the editorship of Yu. A. Holodov, M., 1971; Reactions of biological systems to magnetic fields, under the editorship of Yu. A. Holodov, M., 1978; Biological effects of magnetic fields, ed. by M. F. Bar-nothy, N. Y., 1964.

Yu. A. Holodov.