From Big Medical Encyclopedia

BIOLOGICAL RHYTHMS — fluctuations of change and intensity of processes and physiological reactions which cornerstone the changes of metabolism of biological systems caused by influence of external and internal factors are.

Treat external factors: change of illumination (photoperiodism), temperatures (thermoperiodism), perhaps, magnetic field, intensity of space radiations, inflows and otliva, seasonal and solar and lunar influences. Internal factors are the neurohumoral processes proceeding in certain, the speed hereditarily fixed and a rhythm. The river is characteristic an endogennost of generation, small variability of the established duration of cycles throughout ontogenesis of B.'s most.

B.'s frequency of river — from several fractions of a second up to several years. The B. rubles called by internal factors of change of activity with the period from 20 to 28 hours are called okolosutochny, or circadian, rhythms.

The majority fiziol, processes is exposed to periodic vibrations in a human body. From them daily temperature variations of a body are in detail studied. Takes part in regulation of the daily periodical press of functions hypothalamus (see).

At pathology the perversion of many fiziol, processes is noted. E.g., at patients with an idiopathic hypertensia of the II B and the III stage there occurs not decrease, as at healthy at night, and increase in all indicators of arterial pressure, peripheric resistance with simultaneous reduction of systolic and minute volume of blood. These hemodynamic shifts lead to an aggravation of symptoms of patients at night.

The mismatch of a rhythm biol, hours and photoperiodism in autumn and spring seasons is a probable cause of an aggravation hron, diseases of an organovdykhaniye, cardiovascular system, went. - kish. path, etc. Reproduction of some parasites in an organism also has the expressed frequency which is defined partly B. by river of the owner.

Crossing of several time zones by the airplane breaks natural frequency of B. of river of an organism. Adaptation to new conditions proceeds several days. It should be considered at intercontinental flights. By data I. S. Kucherova (1970), a training of athletes according to a rhythm of metabolism, the period to-rogo is equal to 12 — 16 days, allowed to achieve a strength gain for 11% whereas the ordinary training taking into account a week cycle increased force of muscles by only 4%. The interference of the fluctuations of metabolism caused by exogenous and internal causes can lead to change fiziol, functions with the frequencies equal to a difference of frequencies of interfering fluctuations. The reasons of spontaneous fluctuations of metabolism are not defined yet.

Fluctuations of metabolism with the period in the tenth and 100-th fractions of a second are inherent neural biol, to hours. These rhythms are shown by change of reactive properties of neurons. They define some psychophysiological patterns: duration of simple and composite sensomotor reactions, dependence of size of feeling on intensity of signals, limiting values of information volume of a short-term memory etc.

Results of researches B. of river widely apply at the organization of professional work (see), at the organization of a work-rest schedule in space flights, during the scheduling of sports trainings, competitions etc.

Fig. 1. Main characteristics of fluctuations of physiological rhythms: τ — the period; And — amplitude; φ — a phase; M — level; t — time.

Physiological rhythms — cycle variations in various systems of an organism. The main characteristics fiziol, rhythms are: the period, or frequency, fluctuations (number of fluctuations in unit of time), their amplitude (the size of maximum deviation of an indicator in this or that party from an average value or level of fluctuations), the level, a phase and a form (fig. 1). Frequency period is defined by a time slice between the next maxima or minima of an indicator of a condition of an organism. The phase of fluctuation characterizes a condition of oscillatory process in timepoint; it is measured in shares of the period, and in case of sinusoidal fluctuations — in angular and arc units. In a form conditionally allocate the following types fiziol, fluctuations: pulse, sinusoidal, relaxation, mixed. Classification fiziol, rhythms according to F. Halberg is based on the size of frequency period (tab).

In domestic literature for designation of okolosutochny rhythms (with the period of 20 — 28 hours) the term «circadian» is sometimes used.

Fiziol, rhythms classify also by their ratio with periodic environmental changes of dwelling. If the period of rhythms does not match periodic changes of geophysical factors, they are designated as functional (e.g., periodic changes of evapotranspiration rate and exchange at plants, a rhythm of cordial reductions, breath, cycles of a physical activity — walking). If the period of rhythms matches the periods of geophysical cycles, and also is close or multiple them, them call adaptive or ecological. Carry day-night, tidal, lunar and seasonal rhythms to them. In biology adaptive rhythms from positions of the general adaptation of organisms to the habitat are considered (see. Adaptation ), and in physiology — from the point of view of identification of internal mechanisms of such adaptation and studying of dynamics of a functional condition of organisms throughout a long span.

On degree of dependence on external periodic processes mark out the exogenous, acquired (usual) and endogenous rhythms. Exogenous rhythms are caused by change of environmental factors and can disappear under some conditions (e.g., anabiosis at decrease in external temperature). The acquired rhythms arise in the course of an ontogeny on type conditioned reflex (see) also remain during certain time in constant conditions (e.g., caused by the standard schedule of a physical activity, change of muscular working capacity in certain hours of days). Endogenous rhythms are inborn, remain in constant conditions of the environment and are descended (the majority of functional and circadian rhythms). There are also classifications fiziol, rhythms on separate bodies and systems (e.g., the rhythms registered on EEG, cordial reductions).

Fig. 2. Examples of graphics of physiological rhythms at the person: and — the electrocardiogram; — the sphygmogram of a carotid artery; in — the seismocardiogram; — a pnevmogramma; d and e — electroencephalograms (the right and left frontooccipital assignments); — the daily periodical press of a respiration rate (hours of a dream are shaded); z — the daily periodical press of excretion of potassium with urine (hours of a dream are shaded).

Fiziol, rhythms are one of the main forms of manifestation of life activity, are observed at all live organisms and at all levels of the organization of living matter — from subcellular structures to a complete organism. As a rule, they are not strictly periodic vibrations: in certain limits their period, amplitude, a form, level changes. Them records of some fiziol, rhythms at the person (fig. 2) can be an example.

The rhythms arising at assimilation by an organism of rhythmical external signals (e.g., light flashings), various adaptive rhythms are closest to periodic vibrations fiziol. Fiziol, rhythms are characterized by a wide range of frequencies; their period varies from ten-thousand fractions of a second up to several years. In many cases the same indicator at the same time participates in several types of oscillatory changes (e.g., pulse, respiratory and daily changes of arterial pressure, a wave of various frequency on EEG). The rhythms characteristic of one system can be transferred another (e.g., changes of heart rate in beat of breath). Fiziol. rhythms can be disguised by aperiodic fluctuations of the studied indicator (noise) or other rhythmic fluctuations, their form often can be difficult. In this regard the special methods of the analysis allowing to reveal and study the hidden frequency fiziol, processes are developed (Fourier analysis, the autocorrelated analysis, the sliding summing, etc.). The majority fiziol, rhythms is connected with alternation of various functional conditions of the corresponding systems (e.g., reduction and relaxation of muscles, a dream and wakefulness). Therefore in various phases of oscillatory process different reaction to external influences is noted: the different direction of shift of a phase of a daily cycle at operation of the sensor of time at its various moments, lack of reaction to irritation during the refractory period, etc.

Adaptive fiziol, rhythms were developed in the course of evolution as a form of adaptation of organisms to cyclically changing conditions of the environment. Okolosutochny (circadian) rhythms are the most studied. Increase in day and and decrease at night fiziol, the functions providing its physical activity is characteristic of a human body (heart rate, the minute volume of blood, arterial pressure, body temperature, oxygen consumption, a sugar content in blood, physical and intellectual effeciency, etc.). In usual conditions certain ratios between phases of separate okolosutochny rhythms are observed. Assume that maintenance of constancy of these ratios provides the approval of functions of an organism in time designated as internal approval. Besides, under the influence of the factors of the environment changing with daily periodicity (synchronizers, or sensors of time) there is an external approval of circadian rhythms. Distinguish primary (having major importance) and secondary (less significant) synchronizers. At animals and plants as primary synchronizer serves, as a rule, the sunlight, the person has it also social factors.

In constant conditions, i.e. at the greatest possible exception of operation of synchronizers on the person, usually there are changes of the period of okolosutochny fluctuations, and in certain cases there comes the mismatch (desynchronization) of okolosutochny rhythms on frequency. Desynchronization is observed at bystry flights in other zone zones, during the work during a night shift, in polar latitudes. Repeated disturbances of the usual daily schedule can have adverse effect on health of the person. Desynchronization should be considered as one of pathogenetic mechanisms of adverse action of some factors of the environment and the changed mode of life activity on a human body.

Seasonal fluctuations fiziol, indicators at many hematothermal in a certain measure are repeated by daily allowances: during the winter period decrease in exchange and a physical activity, in spring and summer — activation fiziol, processes is noted.

Dynamics okolosutochny fiziol, rhythms at the person and the highest animals is caused not only inborn mechanisms, but also the daily stereotype of activity developed during life. Data on a possibility of a mismatch on the frequency of separate circadian rhythms force to assume existence of a number of rather independent oscillators, each of which regulates a rhythm of a certain, widely branched functional system. It is supposed that in metaphytes the central regulators do not excite fluctuations in peripheral fabrics but only synchronize circadian rhythms inherent in each cell of an organism on the frequency and a phase. According to most of researchers, regulation fiziol, rhythms at the highest animals and the person is carried out by generally gipotalamo-pituitary system. On a nek-eye to data, seasonal and other adaptive types of rhythms are also not simple reaction to cyclic environmental changes of dwelling, and are characterized by a certain endogennost. The account fiziol, rhythms is necessary by drawing up a rational work-rest schedule of the person, at the choice of time of drug intake, especially if it is about hormonal drugs. Fiziol, rhythms have also a certain diagnostic value in clinic, physiology of work and sports medicine: at various diseases and overfatigue their disturbance is noted.

See also Homeostasis , Self-control of physiological functions .

Value of biological rhythms and space flight

in the conditions of space under the influence of physical and social sensors of time which significantly differ from terrestrial (on intensity, duration of influence etc.) occurs disturbance usual and new B.'s formation by the river. The mode of lighting and ambient temperature in a cabin of the ship, a noise factor are among the main physical sensors of time. Social sensors of time are features of a work-rest schedule of astronauts: a rhythm of a dream and wakefulness, the schedule of activity during wakefulness (time for personal hygiene, physical exercises, meal, radio - and telesessions, performance of professional tasks).

In space character of a work-rest schedule has the most significant effect on B.'s reorganization by the river. In flight regime of astronauts, as a rule, significantly differs from usual terrestrial. Creation of the optimum mode of human life in space is possible at the fullest accounting of the following main conditions:

1) lack of usual geophysical sensors of time (change of day and night, daily temperature variations and humidity of the environment, barometric pressure); 2) shifts of a daily cycle — the starting shifts arising at the beginning of flight (to 12 hours), the precession shifts caused by movement of an axis of rotation of the spaceship concerning Earth (for 90 min. once in 4 — 6 days), the orbital shifts determined by gradual decrease in an orbit (for 5 — 25 min. a day); 3) small structure of crew and need of povakhtenny watch (i.e. change for each crew member of a sleep pattern and wakefulness); 4) tension of labor process. Long (more than 3 days) change of a usual dynamic stereotype of life activity can lead to a desynchronosis (change of reactivity of an organism, emergence various mental and fiziol, shifts as a result of a mismatch of a day-night rhythm of functional systems of an organism and a rhythm of sensors of time). At a desynchronosis complaints to a bad dream, reduction of appetite, irritability are typical. Decrease in working capacity, a mismatch on a phase with sensors of time of heart rate and breath, blood pressure, body temperature and other functions is noted. Degree of manifestation of a desynchronosis depends first of all on specific features of an organism, its state, age, character of sensors of time and degree of synchronism of a daily cycle of an organism with them.

Adaptation of the person to new system of sensors of time, B.'s reorganization by the river happen gradually, and various functions of an organism are reconstructed on a new rhythm in different terms: dynamics of the highest cortical functions — during 1 — 2 days, the heart rate and body temperature — during 5 — 7 days, intellectual working capacity — during 3 — 10 days. The new or partially changed rhythm long remains fragile and can be quickly enough destroyed. In the course of reorganization of a day-night rhythm it is possible to allocate 3 stages: 1) the hidden stage (preservation of a former stereotype during 1 — 3 days); 2) stage of visible reorganization (2 — 9 days); 3) stage of deep reorganization (consolidation of a new stereotype). Features of adaptation of astronauts to the changed daily mode and consequently, and new B.'s formation by the river are defined by degree of a deviation of the new mode from a usual daily routine, ability of an organism of astronauts to reorganization on a new day-night rhythm and other factors.

Achievement of more bystry and strong formation of new B. of river, good health of astronauts and high performance during the flight requires whenever possible full compliance of a rhythm of a dream and wakefulness to natural day-night rhythms of an organism, rhythm of the periods of a dream and wakefulness, physiologically optimum distribution of time for implementation of the main procedures of a daily routine, psychophysiologically reasonable distribution of types of activity (taking into account their tension, duration etc.), extremely exact observance of the mode, «shaking» of the usual mode of life activity before transition to the new schedule of days and «inoculation» of the new mode, artificial stimulation of adaptation of an organism to the new mode (with the help pharmakol, means, by active self-control of functions etc.).

Exact data on B.'s course by the river in a human body are necessary for the correct diagnosis, therapy of l of prevention of many diseases. Without B. methodically correct carrying out scientific research in biology and medicine is impossible for river. B. rubles draw to themselves escalating attention of physiologists, psychologists, hygienists, clinical physicians of various profiles and other specialists.

There are three hypotheses of B.'s emergence by the river (the major biological rhythm — circadian, pl okolosutochny, a rhythm is considered first of all). Most of researchers indicates a possibility of an endogenous origin of B. of river in the course of evolutionary development — as result of natural adaptation of an organism to the changing conditions of the environment [E. Bunning, 1961; J. Asclioff, 1965; B. S. Alyakrinsky, 1975]. On other hypothesis the circadian rhythm is «the resulting size» of shorter rhythms of separate bodies [A. Sollberger, 1969]. The third hypothesis considers rhythmic fluctuations as result of continuous influence space and geo-physical. factors of the getting character [F. A. Brown, 1964].

In 1960 the First international symposium on biological rhythms was called (Kold-Spring — Harbor, the USA). International about-in on B.'s studying by the river it was created in 1937; at the same time B.'s existence by the river became known in 1929 when the fr. astronomer de Meran found out that leaves of plants within a day make the periodic movements. The main problems of a bioritmologiya are covered by «Journal Interdisciplinary Circle Research», «International Journal of Chronobiology» and other editions.

B.'s presence by the river (or oscillatory processes) provides self-updating and self-reproduction of an organism as whole in specific conditions of the environment. The course of reactions at the same time shall change in relation to external influences not according to the tough program, and according to the program providing the optimum relation of an organism with the environment at each this moment. Exactly thanks to existence of fluctuations of change biol, processes are passing. In the absence of oscillatory process of change become irreversible and at achievement of a certain limit balance between an organism and the environment is broken that finally leads to disorganization of functions and death of an organism. Fluctuations promote return of an organism to a reference state, allowing to carry out the new response to external influences.

Rhythmic changes of initial level of functions provide distinction in reaction of an organism to the same influence depending on these conditions of the environment.

Long time was considered that the endogenous component B. of river develops at the person within the first year of life. Researches of the last years showed that each child from the moment of the birth possesses own circadian rhythm with the period from 23 to 25 hour. Synchronization of a rhythm with 24-hour days occurs approximately between the 6th and 16th week after the birth; in the beginning there are ultraday-night rhythms which then pass into daily allowance. Electric resistance of skin on the 1st week shows a day-night rhythm. In the first days of life the low-amplitude rhythm of temperature variations of a body and content of free amino acids in blood serum appears. Formation of each rhythm submits to the law of «the minimum ensuring functions» — first of all rhythms of those functions which have bigger value for maintenance of life of the child (see are consolidated. Sistemogenez ). Therefore between different functions of the same body there is a certain mismatch — a so-called age dissinkhronization, edges gradually disappears in process of growth and development of an organism. Also amplitude of rhythms increases; in the prepubertatny and pubertal periods it exceeds optimum values due to reorganization of ratios of neurohumoral and endocrine components of processes of regulation at this age and is shown in lability of vegetative functions, fluctuation of working capacity, etc.

There is a point of view that aging of an organism represents gradual loss of a rhythm, and both in formation of rhythms, and at their loss (fading) the expressed heterochronia is observed.

B.'s studying by the river allowed to formulate new idea of norm in medicine, a cut assumes not only existence of constants fiziol, processes in the morning (when conduct the main a wedge, researches), but also their rhythmic changes for days. So, concentration of 17 hydroxycorticosteroids in a blood plasma, normal for morning, indicates a stressful condition of an organism in the evening. On the other hand, the concept about norm considers existence and longer rhythms: e.g., level 200 — 210 mg of % of cholesterol in blood and is in the fall normal in the winter, and in the spring and in the summer exceeding norm (N. P. Golikov, P.P. Golikov, 1973).

According to the changed idea of norm, bioritmologichesky approach found application and in diagnosis. E.g., predpatol. and patol, the state can be established on disturbance of a rhythm of change of these or those indicators or functions. In particular, the rhythm of body temperature is constantly considered in clinic both at diagnosis of diseases, and at assessment of a condition of the patient in the course of treatment; at the weakened and often ill school students inversion of a rhythm of body temperature is observed. At acute respiratory diseases the day-night rhythm of an alkaline phosphatase and a succinatedehydrogenase in peripheral blood lymphocytes disappears, at convalescents it is perverted, and with recovery is normalized on amplitude and on a phase; on this basis of R. P. Narcissuses (1970) suggests to judge by recovery of an activity rhythm of enzymes of leukocytes of blood about efficiency of the carried-out treatment.

In medical practice the accounting of fluctuations fiziol, functions of a human body is of great importance. So, for patients with cardiovascular diseases (stenocardia, a hypertension, etc.) especially adverse period is night time when the frequency of attacks increases; change of level of a prothrombin and other components of coagulant system of blood, and also narrowing of coronary vessels lead to the bigger frequency of myocardial infarctions at night at this time.

Treatment by hormonal drugs also shall be based according to B. of river. Imitation fiziol, a rhythm of products of corticosteroids (3/5 daily doses in the morning, other part every 3 hour with the last inclusion in 17 hours) allows to receive big efficiency of hormonal therapy and to reduce the frequency of side effects and complications. The antihistaminic effect of some medicinal substances is most expressed in the morning and minimum in late evening. Use of the majority of medicines for women shall be coordinated with a current of an ovarian and menstrual cycle.

Practical use of bioritmologichesky data is possible only at the accounting of specific features of B. of river. Individual «phase cards», despite intraindividualny distinctions (distinctions day by day), are very similar. At different persons of a phase of various interconnected functions shall not be identical; the phase of the same function can vary at various individuals up to inversion. Distinction in working capacity at people of «morning» and «evening» types is an example: one persons prefer to work in early morning, others in evening and even night hours of days, the third do not feel rhythmic fluctuations of working capacity. Researches showed that there are distinctions not only in working capacity, but also in a condition of vegetative functions. There are data about nek-rum distinction of extreme biorhythmic types on features of the personality, on a rhythm of food and incidence that allows to assume at them distinctions in responses to external irritation. In this regard the special attention to the organization of a work-rest schedule of the people belonging to various biorhythmic types is required. Therefore the flexible working hours applied in some countries, or «fleks-time» deserve attention [Reynmyoller-Shrek (T. Reinmoller-Schreck), 1971], to-rogo reduction of number of obligatory prisutstvenny hours and increase in a number of hours which the person can work in any time, convenient for himself is the cornerstone.

It is considered that the more stoutly is used in the organizations of the work «principle of a rhythm», i.e. compliance of an akrofaza (the highest level) of the main fiziol, functions of the most intensive activity, the all professional activity of the person proceeds more successfully. As show researches, efficiency of the person during the period of wakefulness most often changes on the two-humped curve which received the name «physiological curve of working capacity». On it two main periods (peak) of high performance matching on time the periods of a high level fiziol, functions — between 10 and 12 hours and between 16 and 18 hours clearly are traced; apprx. 14 hours falling of working capacity is, as a rule, observed. It is considered that time of day affects during the work at forced speed more than when the free rhythm is allowed. At night efficiency of the person is much lower, than in the afternoon. Especially adverse period is the time term from 1 to 3 — 4 hours of night: sharply the number of the industrial accidents caused by «a human factor», number of production mistakes increases there comes the exhaustion quicker.

Most of researchers considers that night work represents considerable biol, loading for the person. However rhythmic fluctuations of working capacity are less stereotypic and more changeable, than rhythms of vegetative functions, and long work during a night shift allows at the expense of adaptation opportunities of an organism to create a new daily stereotype. Therefore so-called shpringerovsky change (a 12-hour shift and 24-hour rest) is less favorable for an organism, than weeks-long work during a night shift. At the organization of replaceable work it is necessary that a transfer of workers into new change was made either through short, or through the long periods.

Long cyclic processes. It is conditionally possible to carry all rhythms of low frequency to them. In phylogenetic development of an organism long cyclic processes are connected with processes of reproduction, promoting prosperity of a look. At animals synchronization of these rhythms provides ability of individuals to pairing in certain spans of year that creates optimal conditions for continuation of a look.

The Okolonedelny rhythm which, strictly speaking, shall be carried to socially caused pararhythm differs in low amplitude and is shown in fluctuations of working capacity, excretion with urine 17 of ketosteroids, etc.

the Okolomesyachny rhythm at women is most often connected with an ovarian and menstrual cycle; periodic changes of duration of a dream, emotional lability, etc. are connected with it. It is necessary to emphasize that extragenital cycles define big stability of a female body since the oscillatory mode trains all fiziol, systems and functions.

Settlement rhythms

In the 60th years of this century became widely known so-called settlement rhythms: 23-day (physical), 28-day (emotional) and 33-day (intellectual) rhythm. According to authors of the theory these rhythms «arise» from the moment of the birth and repeat with surprising constancy all life. The first half of the period of each rhythm is characterized by a favorable condition of an organism, and the second — deterioration physical., emotional and intellectual state. However the greatest danger to the person is constituted by «critical days» or those moments when imagined curve (sinusoids) cross the zero line. If to consider these rhythms, then it is possible to prevent accidents, diseases, etc. easily. The theory of settlement rhythms, despite the absence of evidence-based recommendations, drew attention to itself, and use of this theory sometimes brought practical progress due to influence psikhol, factors (big care, confidence in success, etc.). The main lack of the theory of settlement rhythms — the statement of absolute stability and simultaneity of start of all rhythms; it contradicts the known data saying that the philosophy of development of an organism is the heterochronia that autonomy of each of three rhythms can lead only to a constant desynchronosis and that physical., emotional and intellectual states closely are also continuous interconnected.

Seasonal rhythms

Numerous researches established seasonal rhythm of mental and muscular irritability, a metabolism, a physical activity and many other indicators. Seasonal rhythms play an essential role in formation and a current patol, process at the person. Seasonal frequency of many diseases is known (a peptic ulcer of a stomach and duodenum, appendicitis, rheumatism, etc.). There is a seasonal recurrence in a disease of leukoses, in an exacerbation of a hypertension, increase of attacks of stenocardia and myocardial infarction, etc. In experiments on animals seasonal rhythm in the speed of healing of wounds is shown. Statistically the seasonal rhythm is traced in birth rate: the maximum number of childbirth happens in March — May, and minimum — in November — February (N. G. Gulyuk, 1961). There are diseases in which development the seasonal factor plays the main role. E.g., at Eskimos so-called Arctic hysteria is described, the cut is the cornerstone the strengthened allocation from an organism of calcium in winter time (in 8 — 10 times more, than in the summer).

The great value is attached to a seasonal rhythm in balneology. Change of climatic zones shall submit to the general rule: acceleration of the coming season, than return to past is more preferable.

There are rhythms with longer period — two - three-year cycles. These are first of all stages of intensive growth at children's and teenage age. Three-year frequency is noted during tubercular process — in 4, 7, 10 and 13 years from the beginning of a disease most often there is recurrence and the expressed Mantoux tests are observed.

It is known 5-6-and 11-year frequency of developing of some diseases, to-ruyu to some extent connect with influence geo-, heliophysical factors.

The changes happening in the environment as well as processes in a human body, are strictly rhythmical. Various parameters fluctuate with the period from shares of seconds to one thousand years. Such fluctuations in the environment quite often match fluctuations of processes in a human body, inborn B. of river to-rogo allow it to react to external stimuluses adequately.

Bibliography: Biological clock under the editorship of S.E. Shnol, the lane with English, M., 1964, bibliogr.; B yu N of N and N of E. Rhythms of physiological processes, the lane with it., M., 1961, bibliogr.; Iberal A. S. and Mac-Kallok U. S. Gomeokinez — the organizational principle of complex live systems, in book: The general vopr, fiziol, mechanisms, under the editorship of V. A. Trapeznikov, page 55, M., 1970; I. S. Drivers of ides of river. Long biological dshtma in dynamics of muscular efficiency of the person, in book: Cybernetics and vychisliteln. the equipment, under the editorship of K. A. Ivanov - Murom go, century 7, page 71, Kiev, 1970, bibliogr.; From bosoms and A. D m. Ecological zoophysiology, page 98, M., 1971, bibliogr.; To Emma A. M. Biological clock, Novosibirsk, 1967, bibliogr.; S m i t h A. The seasons, life and its rhythms, N. Y., 1970, bibliogr.; S about 1 1 b e of of g since And. and. the lake of Automation in biological rhythm research with special reference to studies on homo, in book: Cell, aspects biorhythms, ed. by H. Mayersbach, p. 184, B. — N. Y., 1967, bibliogr.

Physiological rhythms — K. M. bulls and With l about N and A. D m. Cortical mechanisms of physiology of «time» in an organism of animals and the person, in book: Experience of studying of periodic changes fiziol, functions in an organism, under the editorship of. K. M. Bykova, page 3, M., 1949; At with to and y V. I. and Gubsky L. V. Circadian rhythms and mechanisms of the circadian organization, Usp. sovr. biol., t. 68, century 1, page 90, 1969, bibliogr.; Kandrori. C. Sketches on physiology and hygiene of the person on Far North, page 169, M., 1968, bibliogr.; Mosquitoes F. I., Zakharov L. V. and Lisovsky V. A. A day-night rhythm of physiological functions at the healthy and sick person, L., 1966, bibliogr.; L and-vanov M. N., Lebedev A. N. and Krasavin V. A. Value of spontaneous activity of neurons for chain reactive processes, Zhurn. vyssh. nervn. deya-teln., t. 16, century 2, page 292, 1966; AschoffJ. Desynchronization and resynchronization of human circadian rhythms, Aerospace Med., y. 40, p. 844, 1969; Cloudsley-Thompson J. L. Rhythmic activity in animal physiology and behavior, N. Y. - L., 1961; Ή 1 b e r g F. Chronobio-logy, Ann. Rev. Physiol., v. 31, p. 675, 1969, bibliogr.; M e n z e 1 W. Menschliche Tag-Nacht-Rhythmik und Schichtarbeit, Basel — Stuttgart, 1962; Mills J. N. Human circadian rhythms, Physiol. Rev., v. 46, p. 128, 1966; Richter C. P. Biological clocks in medicine and psychiatry, Springfield, 1965, bibliogr.

Value B. of river in space flight — Alyakrinsky B. S. The principles and ways of a research of a problem of space days, in book: Sketches psikhofiziol, work of astronauts, under the editorship of H. N. Turovsky, page 68, M., 1967; it, the Principles of creation of a work-rest schedule of the person in space, Kosmichesk. biol, and medical, t. 5, No. 2, page 53, 1971; Litsov A. N. The daily periodical press of physiological functions and efficiency of the person at the mode with frequent change of the period of a dream and wakefulness, in the same place, No. 1, page 44; With h e m i n P. Problfcmes biologiquos pos^s par l’astronautique, Biol. m6d. (Paris), t. 59, p. 18, 1970; Poppel E. Desynchronisationen circadianer Rhytmen innerhalb einer isolierten Gruppe, Pfliigers Arch. ges. Physiol., Bd 299, S. 364, 1968.

Alyakrinsky B. S. Bases of the scientific organization of work and rest of astronauts, M., 1975, bibliogr.; Gulyuk N. G. Seasonality and daily rhythmics of childbirth at women, Dependence of some complications in labor from daily rhythmics of patrimonial activity, Akush, and ginek., No. 6, page 45, 1961; Biorhythms and human reproduction, ed. by M. Ferin a.o., N. Y., 1974.

B. A. Krasavin, A. H. Lebedev; B. A. Bodrov (tousle.), L. A. Lugovoi (physical.). V. A. Doskin, H.A. Lavrentyeva.