Biological rhythms— periodically repeating changes in the nature and intensity of biological processes and phenomena in living organisms. Biological rhythms physiological functions so accurate that they are often called the “biological clock.”
There is reason to believe that the time counting mechanism is contained in every molecule human body, including in DNA molecules that store genetic information. The cellular biological clock is called “small”, in contrast to the “large” one, which is believed to be located in the brain and synchronizes all physiological processes in the body.
Classification of biorhythms.
Rhythms, set by the internal “clock” or pacemakers, are called endogenous, Unlike exogenous, which are regulated by external factors. Most biological rhythms are mixed, that is, partly endogenous and partly exogenous.
In many cases, the main external factor regulating rhythmic activity is photoperiod, i.e., the length of daylight. This is the only factor that can be a reliable indication of time and is used to set the "clock".
The exact nature of the clock is unknown, but there is no doubt that there is a physiological mechanism at work that may involve both neural and endocrine components.
Most rhythms are formed during the process of individual development (ontogenesis). Thus, daily fluctuations in activity various functions the child is observed before his birth, they can be registered already in the second half of pregnancy.
- Biological rhythms are realized in close interaction with the environment and reflect the peculiarities of the organism’s adaptation to the cyclically changing factors of this environment. The rotation of the Earth around the Sun (with a period of about a year), the rotation of the Earth around its axis (with a period of about 24 hours), the rotation of the Moon around the Earth (with a period of about 28 days) lead to fluctuations in illumination, temperature, humidity, tension electro magnetic field etc., serve as a kind of indicators, or sensors, of time for the “biological clock”.
- Biological rhythms have large differences in frequency or period. There is a group of so-called high-frequency biological rhythms, the periods of oscillations of which range from a fraction of a second to half an hour. Examples include fluctuations in the bioelectrical activity of the brain, heart, muscles, and other organs and tissues. By recording them using special equipment, they obtain valuable information about the physiological mechanisms of the activity of these organs, which is also used for diagnosing diseases (electroencephalography, electromyography, electrocardiography, etc.). The rhythm of breathing can also be included in this group.
- Biological rhythms with a period of 20-28 hours are called circadian (circadian, or circadian), for example, periodic fluctuations throughout the day in body temperature, pulse rate, blood pressure, human performance, etc.
- There is also a group of low frequency biological rhythms; these are peri-weekly, peri-monthly, seasonal, peri-annual, perennial rhythms.
The basis for identifying each of them is clearly recorded fluctuations of any functional indicator.
For example: The circadian biological rhythm corresponds to the level of excretion in the urine of some physiologically active substances, perimonthly - the menstrual cycle in women, seasonal biological rhythms - changes in sleep duration, muscle strength, morbidity, etc.
The most studied is the circadian biological rhythm, one of the most important in the human body, acting as a conductor of numerous internal rhythms.
Circadian rhythms are highly sensitive to the action of various negative factors, and disruption of the coordinated functioning of the system that generates these rhythms is one of the first symptoms of a disease in the body. Circadian fluctuations in more than 300 physiological functions of the human body have been established. All these processes are coordinated in time.
Many circadian processes reach maximum values during the day every 16-20 hours and minimum values at night or in the early morning hours.
For example: At night a person has the most low temperature bodies. By morning it increases and reaches a maximum in the afternoon.
The main reason for per diem fluctuations physiological functions in the human body there are periodic changes in the excitability of the nervous system, depressing or stimulating metabolism. As a result of changes in metabolism, changes in various physiological functions occur (Fig. 1).
For example: The respiratory rate is higher during the day than at night. At night, the function of the digestive apparatus is reduced.
Rice. 1. Daily allowance biological rhythms in the human body
For example: It has been established that the daily dynamics of body temperature has a wave-like character. At about 6 p.m., the temperature reaches its maximum, and by midnight it decreases: its minimum value is between 1 a.m. and 5 a.m. The change in body temperature during the day does not depend on whether a person is sleeping or engaged in intensive work. Body temperature determines speed of biological reactions During the day, metabolism is most intense.
Sleep and awakening are closely related to the circadian rhythm. A decrease in body temperature serves as a kind of internal signal for rest to sleep. Throughout the day it changes with an amplitude of up to 1.3°C.
For example: By measuring body temperature under the tongue (with a regular medical thermometer) every 2-3 hours for several days, you can quite accurately determine the most appropriate moment for going to bed, and use temperature peaks to determine periods of maximum performance.
Grows during the day heart rate(heart rate), higher arterial pressure(BP), more often breathing. Day after day, by the time of awakening, as if anticipating the increasing need of the body, the content of adrenaline in the blood increases - a substance that increases heart rate, increases blood pressure, and activates the work of the whole organism; By this time, biological stimulants accumulate in the blood. Reducing the concentration of these substances in the evening is an indispensable condition good sleep. It is not for nothing that sleep disturbances are always accompanied by excitement and anxiety: in these conditions, the concentration of adrenaline and other biologically active substances in the blood increases, the body long time is in a state of "combat readiness". Subject to biological rhythms, each physiological indicator can significantly change its level during the day.
Life routine, acclimatization.
Biological rhythms are the basis for the rational regulation of a person’s life schedule, since high performance and good health can only be achieved if the rhythm of life corresponds to the rhythm of physiological functions inherent to the body. In this regard, it is necessary to wisely organize the regime of work (training) and rest, as well as food intake. Deviation from correct mode nutrition can lead to a significant increase in weight, which in turn, disrupting the vital rhythms of the body, causes changes in metabolism.
For example: If you eat food with a total calorie content of 2000 kcal only in the morning, weight decreases; if the same food is taken in evening hours, increases. In order to maintain the body weight achieved by the age of 20-25, food should be taken 3-4 times a day in strict accordance with individual daily energy expenditure and at those hours when a noticeable feeling of hunger appears.
However, these general patterns sometimes hide the diversity of individual characteristics of biological rhythms. Not all people experience the same type of fluctuations in performance. Some, the so-called “larks,” work energetically in the first half of the day; others, “owls,” in the evening. People classified as “early people” feel drowsy in the evening, go to bed early, but when they wake up early, they feel alert and productive (Fig. 2).
Easier to tolerate acclimatization a person, if he takes (3-5 times a day) hot meals and adaptogens, vitamin complexes, and physical exercise increases gradually as you adapt to them (Fig. 3).
Rice. 2. Work capacity rhythm curves during the day
Rice. 3. Daily rhythms of life processes under constant external living conditions (according to Graf)
If these conditions are not met, so-called desynchronosis (a kind of pathological condition) may occur.
The phenomenon of desynchronosis is also observed in athletes, especially those training in hot and humid climates or mid-altitude conditions. Therefore, an athlete flying to international competitions must be well prepared. Today there is a whole system of measures aimed at maintaining familiar biorhythms.
For the human biological clock, the correct movement is important not only in the daily rhythm, but also in the so-called low-frequency rhythms, for example, in the periweekly rhythm.
It has now been established that the weekly rhythm is artificially developed: no convincing data have been found on the existence of innate seven-day rhythms in humans. Obviously, this is an evolutionarily fixed habit. The seven-day week became the basis of rhythm and rest in ancient Babylon. Over thousands of years, a weekly social rhythm has developed: people are more productive in the middle of the week than at the beginning or end of it.
The human biological clock reflects not only daily natural rhythms, but also those that have a longer duration, such as seasonal ones. They manifest themselves in an increase in metabolism in the spring and a decrease in it in the fall and winter, an increase in the percentage of hemoglobin in the blood and a change in the excitability of the respiratory center in spring and summer.
The state of the body in summer and winter time to some extent corresponds to his condition day and night. Thus, in winter, compared to summer, the blood sugar level decreased (a similar phenomenon occurs at night), and the amount of ATP and cholesterol increased.
Biorhythms and performance.
Rhythms of performance, like the rhythms of physiological processes, are endogenous in nature.
Performance may depend on many factors acting individually or jointly. These factors include: level of motivation, food intake, environmental factors, physical fitness, health status, age and other factors. Apparently, the dynamics of performance are also affected by fatigue (in elite athletes, chronic fatigue), although it is not entirely clear how exactly. Fatigue that occurs when performing exercises (training loads) is difficult to overcome even for a sufficiently motivated athlete.
For example: Fatigue reduces performance, and repeated training (with an interval of 2-4 hours after the first) improves the athlete’s functional state.
During transcontinental flights, the circadian rhythms of various functions are rearranged at different speeds - from 2-3 days to 1 month. To normalize cyclicity before the flight, you need to shift your bedtime by 1 hour every day. If you do this within 5-7 days before departure and go to bed in a dark room, you will be able to acclimatize faster.
When arriving in a new time zone, it is necessary to smoothly enter the training process (moderate physical activity during the hours when the competition will take place). Training should not be of a “shock” nature.
It should be noted that the natural rhythm of the body’s vital activity is determined not only internal factors, but also by external conditions. As a result of the research, the wave nature of changes in loads during training was revealed. Previous ideas about a steady and straightforward increase in training loads turned out to be untenable. The wave-like nature of changes in loads during training is associated with the internal biological rhythms of a person.
For example: There are three categories of “waves” of training: “small”, covering from 3 to 7 days (or slightly more), “medium” - most often 4-6 weeks (weekly training processes) and “large”, lasting several months.
Normalization of biological rhythms allows you to carry out intense physical activity, and training with a disturbed biological rhythm leads to various functional disorders (for example, desynchronosis), and sometimes to diseases.
Source of information: V. Smirnov, V. Dubrovsky (Physiology of physical education and sports).
Biological rhythm is an oscillatory process leading to the reproduction of a biological phenomenon or state of a biological system at approximately equal intervals of time.
We consider it quite natural and are not at all surprised when, for example, we feel sleepy in the evening and go to bed, essentially obeying our biological clock. Even more understandable and not requiring any special explanation seems to us the appearance with the onset of darkness of a feeling of fatigue, which, in fact, causes drowsiness. But if a person spends several weeks doing nothing, in a dimly lit room where no sounds penetrate, then even then he will fall asleep and wake up approximately every 24 hours, as if measuring day by day.
In the life of plants and animals, in addition to sleep, there are many manifestations of other rhythms: more than 2400 years ago, Hippocrates wrote about the ups and downs inherent in the physical state of people, almost 300 years ago (1729), the French mathematician and astronomer Jean Jacques de Meran discovered 24-hour periodic activity in plants, later Christopher Gufelyand (1797), considering fluctuations in body temperature in healthy and sick patients, suggested that the body has an “internal clock”, the course of which is determined by the rotation of the Earth around its axis. He was the first to draw attention to the universality of rhythmic processes in biological objects and emphasized that our life obviously repeats itself in certain rhythms, and every day represents a small summary of our life.
The progressive development of the doctrine of biological rhythms led to the emergence of a new interdisciplinary fundamental science - chronobiology, which studies the patterns of the life processes of an organism over time. The study of biological rhythms has become an integral part of chronobiology. However, to date, despite the introduction of chronobiology methods into other areas of study of living systems and the formation of new directions in biomedical science (chronomedicine, chronopharmacology, chronopathology, etc.), scientists have not developed a unified vocabulary for the new science, in As a result, manifestations of chronobiological phenomena are often named differently, and terms that have already been established are used in a different sense or attempts are made to revise more or less established terms. As we explore the subject, we will examine these contradictions.
The concepts of chronobiology and biorhythmology are close, but not identical. According to the most universal definition adopted by the International Society for the Study of Biological Rhythms, chronobiology- a science that objectively studies, on a quantitative basis, the mechanisms of biological time structure, including the rhythmic manifestations of life at all levels of organization of a living system. Indeed, although the study of the periodicity of life phenomena forms the basis of chronobiological approaches, it is not always taken into account that fluctuations are combined with slower changes that are not necessarily periodic.
Biorhythmology- a science that studies the conditions for the occurrence, nature, patterns and significance of biological rhythms. Biorhythm represents fluctuations of any biological process (state), occurring at approximately equal intervals of time, when the process (state) returns to its original cycle. The repeatability of a state (for example, cell division) in a rhythm is relative. In fact, each repetition cycle differs in content from the previous one, but is reproduced according to the same patterns.
The concepts of “cycle” and “rhythm” are close; their use is determined by semantic nuances, which depends on the context. By cyclicity they often mean only the repeatability of events; when using the term “rhythm”, they usually mean that, in addition to the period, its other parameters are also known.
The intensity of the process throughout the cycle changes according to complex and different laws for different processes, so that the curves reflecting it (waveform) have a complex configuration, for example, the configuration of an electrocardiogram, the description of which requires the use of theories of limit cycles and relaxation oscillations.
The simplest curve describing cycles (rhythms) is a sine wave, characterized by certain parameters used to describe the biological rhythm.
Classification of biorhythms
A manifestation and characteristic that allows one to judge a person’s temporal organization is his chronotype. Most often, this term refers to the circadian dynamics of indicators characterizing the general condition of the body. A person's chronotype is individual, because... due, on the one hand genetic mechanisms, and on the other hand, the interaction of the organism with the environment.
Most often, a person’s chronotype is determined by the level of performance - the active phase of the biological rhythm “sleep-wake”. Differences in this rhythm made it possible to classify people into “morning” groups (“larks”), “evening” groups (“owls”) and “arrhythmic” groups (“pigeons”). “Owls” fall asleep late and wake up late; their maximum daily biorhythms of activity and rest are shifted to later hours, unlike “larks” who wake up early and fall asleep early. For pigeons, their peak activity occurs approximately in the middle of the day. Throughout life, the temporal organization of a person can change: with age, it shifts towards the “lark” This happens due to changes in the rate of secretion of hormones (in particular, the hormone melatonin, which is responsible for the normal rhythmic flow of biological processes in the body). This is where the elderly tend to get up early and go to bed early, while the young tend to stay up late and sleep longer in the morning.
Any biological phenomenon, any physiological reaction have a periodic nature, since living organisms, living for many millions of years under conditions of rhythmic changes in the geophysical parameters of the environment, have also developed ways of adapting to them.
Rhythm- a fundamental characteristic of the functioning of a living organism - is directly related to the mechanisms of feedback, self-regulation and adaptation, and the coordination of rhythmic cycles is achieved thanks to an important feature of oscillatory processes - the desire for synchronization. The main purpose of rhythm is to maintain the homeostasis of the body when environmental factors change. In this case, homeostasis is understood not as the static stability of the internal environment, but as a dynamic rhythmic process - rhythmostasis, or homeokinesis.
The body’s own rhythms are not autonomous, but are associated with the rhythmic processes of the external environment: the change of day and night, annual seasons, etc.
External time setters
There is no uniformity in the terminology characterizing external factors and the internal fluctuations generated by them. For example, there are names “external and internal time sensors”, “time setters”, “internal biological clocks”, “generators of internal oscillations” - “internal oscillators”.
Biological rhythm - periodic repetition of some process in a biological system at more or less regular intervals. Biorhythm is not just repeating, but also a self-sustaining and self-reproducing process. Biological rhythms are characterized by period, frequency, phase and amplitude of oscillations.
Period is the time between two points of the same name in a wave-like changing process, i.e. the duration of one cycle until the first repetition.
Frequency. Rhythms can also be characterized by frequency - the number of cycles occurring per unit of time. The frequency of rhythms can be determined by the frequency of periodic processes occurring in the external environment.
Amplitude is the greatest deviation of the studied indicator in any direction from the average. The amplitude is sometimes expressed through the mesor, i.e. as a percentage of the average value of all its values obtained during rhythm registration. Double the amplitude is equal to the amplitude of the oscillations.
Phase. The term "phase" refers to any distinct part of a cycle. Most often this term is used to describe the connection of one rhythm with another. For example, the peak of activity in some animals coincides in phase with the dark period of the light-dark cycle, in others - with the light period. If the two selected time periods do not coincide, then the term phase difference is introduced, expressed in the corresponding fractions of the period. Being ahead or behind in phase means that an event occurred earlier or later than expected. The phase is expressed in degrees. For example, if the maximum of one rhythm corresponds to the minimum of another, then the phase difference between them is 180?.
Acrophase is a point in time during which maximum value the indicator under study. When recording acrophase (batiphase) over several cycles, it was noted that the time of its onset varies within certain limits, and this time is identified as a zone of phase wandering. The size of the phase wander zone is probably related to the period (frequency) of the rhythm. The frequency and phase of biorhythms are influenced not only by the frequency and phase of the external oscillatory process, but also by its level.
Exists circadian rule: Diurnal organisms are characterized by a positive correlation between illumination and circadian rhythm frequency, while nocturnal organisms are characterized by a negative correlation.
Classifications of biorhythms
The classification of rhythms depends on the selected criteria: according to their own characteristics, according to the functions they perform, the type of process that generates the oscillations, as well as according to the biosystem in which cyclicity is observed.
The range of possible rhythms of life covers a wide range of time scales - from the wave properties of elementary particles
(microrhythms) to global cycles of the biosphere (macro- and megarhythms). The limits of their duration range from many years to milliseconds, the grouping is hierarchical, but the boundaries between groups are in most cases arbitrary. The upper limit of mid-frequency rhythms is set at 28 hours to 3 seconds. Periods from 28 hours to 7 days are either classified as a single group of mesorhythms, or some of them (up to 3 days) are included in mid-frequency ones, and from 4 days - in low-frequency ones.
Rhythms are divided according to the following criteria (Yu. Ashoff,
1984):
According to its own characteristics (for example, by period);
By biological system (for example, population);
According to the nature of the process that generates rhythm;
According to the function that rhythm performs.
A classification based on the structural and functional levels of life organization is proposed:
Rhythms of the molecular level with a period of the second-minute range;
Cellular - from circa-hourly to circa-annual; organismal - from circadian to perennial;
Population-species - from perennial to rhythms lasting tens, hundreds and thousands of years;
Biogeocenotic - from hundreds of thousands to millions of years;
Biosphere rhythms - with a period of hundreds of millions of years.
The most popular classification of biological rhythms is F. Halberg and A. Reinberg (1967) (Fig. 4.1).
SEPARATE RHYTHMS
In living nature, the most clearly expressed rhythms are those with a period of about 24 hours - circadian (lat. circa- near, dies- day). Later prefix "circa" began to be used for other endogenous rhythms,
Rice. 4-1.Classification of biorhythms (F. Halberg, A. Reinberg)
corresponding to the cycles of the external environment: near-tidal, near-lunar, perennial (circatidal, circalunar, circannual). Rhythms with a period shorter than the circadian are defined as ultradian, while those with a longer period are infradian. Among the infradian rhythms, circaseptidian with a period (7–3 days), circavigentidian (21–3 days), circatrigentidian (30–5 days) and circannual (1 year–2 months) are distinguished.
Ultradian rhythmics
If the biological rhythms of this range are arranged in order of decreasing frequency, then a range from multi-hertz to multi-hour oscillations is obtained. Nerve impulses have the highest frequency (60-100 Hz), followed by EEG oscillations with a frequency from 0.5 to 70 Hz.
Decasecond rhythms were recorded in brain biopotentials. This range also includes fluctuations in pulse, respiration, and intestinal motility. Minute rhythms characterize the psychological and emotional state of a person: the bioelectrical activity of muscles, heart rate and respiration, the amplitude and frequency of movements change on average every 55 s.
Decaminute (90 min) rhythms were discovered in the brain mechanisms of night sleep, which were called slow- and fast-wave (or paradoxical) phases, while dreams and involuntary eye movements occur in the second phase. The same rhythm was subsequently discovered in ultra-slow fluctuations in the biopotentials of the waking brain, associated with the temporal dynamics of attention and operator vigilance.
Circular rhythms were found not only at the systemic level, but also at lower hierarchical levels. Many phenomena occurring at the cellular level have this rhythm: protein synthesis, changes in cell size and mass, enzymatic activity, cell membrane permeability, secretion, electrical activity.
Circadian oscillations
The circadian system is the basis through which the integrative activity and regulatory role of the neuroendocrine system manifests itself, carrying out the precise and subtle adaptation of the body to constantly changing environmental conditions.
Circadian periodicity was found in integral vital signs.
Performance at night decreases, and the time required to complete a task, both in the light and in the dark, is longer at night than during the day under the same conditions.
Training in the early morning hours has slightly less effect than in the middle of the day.
Students’ performance is highest in the pre-lunch hours, by 2 p.m. there is a significant decrease, the second rise occurs at 4-5 p.m., then a new decline is observed.
Daily periodicity is characteristic not only of GNI, but also of the underlying hierarchical systems of the body.
24-hour changes in cerebral and cardiac hemodynamics and orthostatic stability were recorded.
A daily rhythm of the conjugation of the phases of the cardiac cycle and respiration has been revealed.
The literature contains data on a nighttime decrease in pulmonary ventilation and oxygen consumption, a drop in minute volume of respiration (MVR) in young, mature and middle-aged people.
Circadian rhythm is also inherent in the functions of the digestive system, in particular, salivation, secretory activity of the pancreas, synthetic function of the liver, and gastric motility. It was found that the highest rate of acid secretion with gastric juice observed in the evening, the smallest in the morning.
At the level of biochemical individuality, daily cyclicity is open for some substances.
Concentration of macro- and microelements: phosphorus, zinc, manganese, sodium, potassium, rubidium, cesium and chlorine in human blood, as well as iron in blood serum.
Total content of amino acids and neurotransmitters.
Basal metabolic rate and related levels thyroid-stimulating hormone pituitary gland and thyroid hormones.
Sex hormone system: testosterone, androsterone, follicle-stimulating hormone, prolactin.
Hormones of the neuroendocrine stress regulation system - ACTH, cortisol, 17-hydroxycorticosteroids, which accompanies
is caused by cyclical changes in glucose and insulin levels. A similar rhythmicity is known for melatonin.
Infradian rhythms
Biorhythmologists have described not only daily, but also multi-day (about a week, about a month) rhythms, covering all hierarchical levels of the body.
In the literature there is an analysis of the fine spectrum of fluctuations (with periods of 3, 6, 9-10, 15-18, 23-24 and 28-32 days) of heart rate, blood pressure, and muscle strength.
The rhythm of the 5-7 day duration is fixed in the dynamics of intensity energy metabolism, mass and temperature of the human body.
Fluctuations in the results of clinical tests of the content of red blood cells and leukocytes in the blood are well known. In men, the number of neutrophils in venous blood varies with a period from 14 to 23 days.
Among the rhythms of this range, the most studied are the monthly (lunar) cycles. It has been established that during the full moon, the number of cases of postoperative bleeding is 82% higher than at other times; during the lunar phases, the incidence of myocardial infarction increases.
Circannual rhythms
In the body of animals and humans, oscillations of various physiological processes have been discovered, the period of which is equal to one year - perennial (circannual) or seasonal rhythms. Circannual periodicity has been determined for the excitability of the nervous system, hemodynamic parameters, heat production, response to acute cold stress, the content of sex and other hormones, neurotransmitters, child growth, etc.
CHARACTERISTICS OF BIORHYTHMS
When studying periodic phenomena in living systems, it is important to find out whether the rhythm observed in a biological system reflects a reaction to a periodic influence external to this system (exogenous rhythm imposed by the pacemaker) or whether the rhythm is generated within the system itself (endogenous rhythm), finally whether there is a combination of an exogenous rhythm and an endogenous rhythm generator.
Pacemakers and functions
External pacemakers can be simple or complex.
Simple:
Serving food at the same time, which causes simple reactions limited mainly to involvement in the activity of the digestive system;
The change of light and darkness is also a relatively simple pacemaker, but it involves not only sleep or wakefulness (i.e. one system), but the entire organism in activity.
Difficult:
The change of seasons, leading to long-term specific changes in the state of the body, in particular, its reactivity, resistance to various factors: the level of metabolism, the direction of metabolic reactions, endocrine changes;
Periodic fluctuations in solar activity, often causing disguised changes in the body, largely dependent on the initial state.
Relationship between time setters and biorhythms
Our modern ideas about the connection between exogenous time-setters and endogenous rhythms (the idea of a single biological clock, polyoscillatory structure) are shown in Fig. 4-2.
Hypotheses about a single biological clock and the polyoscillatory time structure of the body are quite compatible.
The hypothesis of centralized control of internal oscillatory processes (the presence of a single biological clock) relates primarily to the perception of changes in light and darkness and the transformation of these phenomena into endogenous biorhythms.
Rice. 4-2.Mechanisms of interaction of the body with external time setters
Multioscillatory model of biorhythms. It is assumed that in a multicellular organism a main pacemaker can function, imposing its rhythm on all other systems. The existence (along with the central pacemaker) of secondary oscillators, which also have pacemaker properties, but are hierarchically subordinate to the leader, cannot be ruled out. According to one version of this hypothesis, disparate oscillators can function in the body, which form separate groups that work independently of each other.
MECHANISMS OF RHYTHMOGENESIS
There are several points of view on the mechanisms of rhythmogenesis. It is possible that the source of circadian rhythm is cyclic changes in ATP in the cytoplasm of cells or cycles of metabolic reactions. It is possible that the rhythms of the body determine biophysical effects, namely the influence of:
Gravitational field;
Cosmic rays;
Electromagnetic fields (including the Earth's magnetic field);
Atmospheric ionization, etc.
Rhythms of mental activity
Not only biological and physiological processes, but also the dynamics of mental activity, including emotional states, are subject to natural fluctuations. For example, it has been established that the waking consciousness of a person has a wave nature. Psychological rhythms can be systematized in the same ranges as biological ones.
Ultradian rhythms manifest themselves in fluctuations in perception thresholds, time of motor and associative reactions, and attention. The correspondence of bio- and psychorhythms in the human body ensures normal work of all its organs and systems, so human hearing gives the greatest accuracy in assessing the time interval of 0.5-0.7 s, which is typical for the pace of movements when walking.
Clock rhythms.In the fluctuations of mental processes, in addition to temporary rhythms, so-called clock rhythms were discovered, which depend not on time, but on the sample number: a person cannot always react in the same way to presented stimuli.
If in the previous test the reaction time was short, then next time the body will save energy, which will lead to a decrease in the reaction rate and fluctuations in the value of this indicator from trial to trial. Tactical rhythms are more pronounced in children, and in adults they intensify with a decrease in the functional state of the nervous system. When studying mental fatigue, decasecond or two-minute (0.95-2.3 min) and ten-minute (2.3-19 min) rhythms were identified.
Circadian rhythmscause significant changes in the body’s activity, affecting the mental state and performance of a person. Thus, the electrical sensitivity of the eye changes throughout the day: at 9 a.m. it increases, by 12 p.m. it reaches a maximum and then decreases. Such daily dynamics are inherent not only in mental processes, but also in the psycho-emotional states of the individual. The literature describes the daily rhythms of intellectual performance, subjective readiness for work and the ability to concentrate, short-term memory. Persons with a morning type of performance have a higher level of anxiety and are less resistant to frustrating factors. People of morning and evening types have different thresholds of excitability, a tendency towards extraversion or introversion.
EFFECTS OF CHANGING TIME SETTERS
Biological rhythms are distinguished by great stability; changing the usual rhythms of time-setters does not immediately shift biorhythms and leads to desynchronosis.
Desynchronosis - mismatch of circadian rhythms - a violation of the original architectonics of the body's circadian system. When the synchronization of the body's rhythms and time sensors is disturbed (external desynchronosis), the body enters a stage of anxiety (internal desynchronosis). The essence of internal desynchronosis is a mismatch in the phase of the body's circadian rhythms, which results in various disturbances in its well-being: sleep disorders, loss of appetite, deterioration of well-being, mood, decline in performance, neurotic disorders and even organic diseases (gastritis, peptic ulcer, etc.) . The restructuring of biorhythms is most clearly manifested during rapid movements (air travel) on a global scale.
Long distance travel cause pronounced desynchronosis, the nature and depth of which are determined by: direction, time, duration of the flight; individual characteristics of the body; workload; climatic contrast, etc. Five types of movements are identified (Fig. 4-3).
Rice. 4-3.Chronophysiological classification of types of movement:
1 - transmeridian; 2 - translatitudinal; 3 - diagonal (mixed);
4 - transequatorial; 5 - asynchronous. (V.A. Matyukhin et al., 1999)
Transmeridian movement (1). The main indicator of such movement is the angular velocity of movement, expressed in degrees of longitude. It can be measured by the number of time zones (15?) crossed per day.
If the speed of movement exceeds 0.5 time zones per day, external desynchronosis - the difference in the phases of the actual and expected maximums of the daily curve of physiological functions.
Changing 1-2 time zones does not cause desynchronization (there is a dead zone within which phase desynchronization does not appear). When flying across 1-2 time zones, the flattening of daily fluctuations in physiological functions typical for phase desynchronization is not observed, and the rhythm is gently “delayed” by external time sensors.
As you move further east or west, the phase mismatch increases as a function of time. At different geographic latitudes, the critical angular velocity is achieved at different linear speeds of movement: in subpolar latitudes, even at low speeds corresponding to the speed of a pedestrian, desynchronization cannot be ruled out. Almost everyone's speed Vehicle significantly exceeds 0.5 archours per day. The effect of desynchronization of biological rhythms manifests itself in the most pronounced form with this type of movement.
When the speed of movement exceeds three or more time zones per day, external synchronizers are no longer able to “delay” circadian fluctuations in physiological functions and desynchronosis occurs.
Translatitudinal movement (2) - along the meridian, from south to north or from north to south - without causing a phase mismatch of the sensors, gives an effect perceived as a mismatch of the actual and expected amplitudes of the synchronizers. At the same time, the phases of the annual rhythm change, and seasonal desynchronization appears.
The first place in such movements is the discrepancy between seasonal readiness physiological systems requirements of a different season in a new place. There is no phase mismatch between the rhythms of external sensors and the body’s biorhythms, but their daily amplitudes do not coincide.
The range of movement at which climatic conditions and the structure of photoperiodism in a new place begin to cause tension in the mechanisms for maintaining the seasonal rhythm of physiological functions, depending on geographic latitude: an assessment of the width of the insensitivity zone shows that it can vary from 1400 km at the equator to 150 km at a latitude of 80?.
- “Window of chronophysiological insensitivity”, its linear and angular dimensions depend on latitude. The speed, expressed in the number of “windows” crossed per day, will, at equal linear speed, increase in the direction from the equator to the pole to very large values. Narrowing
“windows” as you move north are an important circumstance, indicating increased chronophysiological tension when moving in subpolar latitudes compared to low or middle latitudes.
Moving diagonally (3) implies changes in longitude and latitude, great climatic contrast and significant changes in standard time. These movements are not a simple sum (superposition) of the effects of “horizontal” (1) and “vertical” (2) movement. This is a complex set of chronobiological stimuli, the reaction to which may differ significantly from reactions to each type of desynchronization considered in isolation.
Moving to another hemisphere (4) crossing the equatorial zone. The main influencing factor of such movement is the contrasting change of season, causing deep seasonal desynchronosis, phase shift and inversion annual cycle physiological functions.
The fifth type of movement is the chronoecological regime, in which the oscillatory properties of the environment are sharply weakened or completely absent. Such movements include:
Orbital flights;
Staying in conditions with sharply weakened daily and seasonal synchronizers (submarines, spacecraft);
Shift work schedules with staggered shift schedules, etc. It is proposed to call environments of this type “asynchronous”. The impact of such “chronodeprivation” causes gross violations of daily and other periodicity.
SUBJECTIVITY OF TIME PERCEPTION
The passage of time is perceived subjectively, depending on the intensity of the physical or mental activity of each individual. Time seems to become more capacious when you are more busy or when it is necessary to take correct solution in an extreme situation.
In a matter of seconds, a person manages to do the most difficult work. For example, a pilot in emergency situation decides to change aircraft control tactics. At the same time he
instantly takes into account and compares the dynamics of development of numerous factors influencing flight conditions.
In the process of studying the subjective perception of time, the researchers used the “individual minute” test. At a signal, the person counts down the seconds, and the experimenter watches the stopwatch hand. It turned out that for some the “individual minute” is shorter than the true one, for others it is longer; the discrepancies in one direction or another can be very significant.
BIOLOGICAL RHYTHMS IN DIFFERENT CLIMATE GEOGRAPHIC CONDITIONS
Highlands. In high altitude conditions, the circadian rhythms of hemodynamics, respiration, and gas exchange depend on meteorological factors and change in direct proportion to changes in air temperature and wind speed and in inverse proportion to changes atmospheric pressure and relative air humidity.
High latitudes. The specific properties of the polar climate and environmental features determine the biorhythms of the inhabitants:
During the polar night there are no reliable circadian fluctuations in oxygen consumption. Since the value of the oxygen utilization coefficient reflects the intensity of energy exchange, the decrease in the range of fluctuations in oxygen consumption during the polar night is indirect evidence in favor of the phase mismatch of various energy-dependent processes.
Residents of the Far North and polar explorers during the polar night (winter) experience a decrease in the amplitude of the daily rhythm of body temperature and a shift of acrophase to the evening hours, and in spring and summer to the daytime and morning hours.
Arid zone. When a person adapts to the desert, rhythmic fluctuations in environmental conditions lead to synchronization of the rhythm of the functional state of the body with these fluctuations. In this way, partial optimization of the activity of compensatory mechanisms under extreme environmental conditions is achieved. For example, the acrophase of the rhythm of the weighted average skin temperature occurs at 16:30, which practically coincides with the maximum air temperature, body temperature
reaches its maximum at 21:00, correlating with the maximum heat generation.
METHODS OF STATISTICAL ASSESSMENT IN CHRONOBIOLOGY
Cosine function. The simplest periodic process is a harmonic oscillatory process, described by a cosine function (Fig. 4-4):
Rice. 4-4.The main elements of the harmonic (cosine) oscillatory process: M - level; T - period; ρ A, ρ B, αφ A, αφ B - amplitudes and phases of processes A and B; 2ρ A - scope of process A; αφ H - phase difference between processes A and B
x(t) = M + рХcos2π/ТХ(t-αφ Х),
Where:
M - constant component; ρ - amplitude of oscillations; T - period, h; t - current time, h; aαφ H - phase, h.
When analyzing biorhythms, they are usually limited to the first member of the series - a harmonic with a period of 24 hours. Sometimes a harmonic with a period of 12 hours is also taken into account. As a result of approximation, the time series turns out to be represented by a small number of generalized parameters - level M, amplitude p, phase αφ.
The phase relationships between two harmonic oscillatory processes can be different. If the phases of two processes are the same, they are called in-phase; if the difference between the phases is T/2, they are called anti-phase. We speak about the phase advance or phase lag of one harmonic process A relative to another B when αφ A<αφ B или αφ A >αφ B respectively.
The described parameters, strictly speaking, can only be used in relation to a harmonic oscillatory process. In fact, the daily curve differs from the mathematical model: it may be asymmetrical relative to the average level, and the interval between maximum and minimum, unlike a cosine wave, may not be equal to 12 hours, etc. In view of these reasons, the use of these parameters to describe a real oscillatory periodic or close to periodic process requires a certain amount of caution.
Chronograms.Along with the harmonic approximation of the time series, the traditional method of presenting the results of biorhythmological research in the form of daily chronograms is widely used, i.e. averaged over many individual measurements of daily curves. On the chronogram, along with the average value of the indicator for a certain hour of the day, a confidence interval is indicated in the form of a standard deviation or error of the average.
There are several types of chronograms found in the literature. If the dispersion of individual levels is large, the periodic component may be masked. In such cases, preliminary normalization of daily curves is used, so that it is not the absolute values of the amplitude p that are averaged, but the relative ones (p/M). For some indicators, the chronogram is calculated in shares (percentages) of the total daily volume of consumption or excretion of some substrate (for example, oxygen consumption or potassium excretion in the urine).
The chronogram gives a fairly clear idea of the nature of the daily curves. By analyzing the chronogram, it is possible to approximately determine the oscillation phase, absolute and relative amplitude, as well as their confidence intervals.
Kosinor- statistical model of biorhythms based on approximation of the oscillation curve of a physiological indicator
harmonic function - cosinor analysis. The purpose of cosine analysis is to present individual and mass biorhythmological data in a comparable, unified form that is accessible for statistical assessments. Daily cosinor parameters characterize the severity of the biorhythm, transition processes during its restructuring, and the presence of a statistically significant difference between some groups and others.
Cosinor analysis has obvious advantages over the chronogram method, since it allows the use of correct statistical methods to analyze the structure of biorhythms.
Cosinor analysis is performed in two stages:
At the first stage, individual daily curves are approximated by a harmonic (cosine) function, as a result of which the main parameters of the biorhythm are determined - the average daily level, amplitude and acrophase;
At the second stage, vector averaging of individual data is carried out, the mathematical expectation and confidence intervals of the amplitude and acrophase of daily fluctuations of the studied indicator are determined.
QUESTIONS FOR SELF-CONTROL
1. Give examples of temporary parameters of the body and its systems?
2. What is the essence of work synchronization? various systems body?
3. What is biological rhythm? What characteristics does it have?
4. What classifications of biorhythms can you give? What is the fundamental difference between different types of biorhythms?
5. Name the mechanisms of rhythmogenesis.
6. What rhythms of mental activity do you know?
7. What happens when timers are removed or changed?
8. What types of movements do you know?
9. Name the methods statistical analysis in chronobiology.
10. What is the fundamental difference between cosinor analysis?
Biological rhythms of health mean the cyclical nature of processes occurring in the body. A person’s internal rhythms are influenced by external factors:
- natural (radiation from the Moon, Earth and Sun);
- social (shifts at the enterprise).
Biorhythmologists or chronobiologists study biorhythms. They believe that biorhythms are periodic processes that occur in living matter. These processes can cover completely different time periods: from a couple of seconds to tens of years. Changes in biological rhythms can be caused by various processes. They can be external (ebb and flow) and internal (heart function).
Classification of biorhythms
The main criterion for dividing rhythms into groups is their duration. Chronibiologists will distinguish three types of human biological rhythms. The longest ones are called low-frequency ones. The amplitude of such fluctuations in the functioning of the body is determined by lunar, seasonal, monthly or weekly intervals. As examples of processes that obey low-frequency rhythms, we can highlight the work of the endocrine and reproductive systems.
The second group includes mid-frequency rhythms. They are limited to a time period from 30 minutes to 6 days. According to the laws of such oscillations it works metabolic process and the process of cell division in the body. Periods of sleep and wakefulness are also subject to these biorhythms.
High frequency rhythms last less than 30 minutes. They are determined by the work of the intestines, heart muscle, lungs and the speed of biochemical reactions.
In addition to the types mentioned above, there are also fixed biorhythms. They are understood as rhythms, the duration of which is always 90 minutes. These are, for example, emotional fluctuations, changes in sleep phases, periods of concentration and heightened attention.
Of particular interest is the fact that biological cycles can be inherited and are determined genetically. Ecology also influences them.
Types of biological rhythms
From birth, the human body is subject to the influence of three rhythms:
- intellectual,
- emotional,
- physical.
A person’s intellectual biological rhythm determines his mental abilities. In addition, he is responsible for caution and rationality in behavior. Representatives of intellectual professions can most strongly feel the influence of this biorhythm: teachers, scientists, professors and financiers. The ability to concentrate and perceive information depends on intellectual biocycles.
The emotional biorhythm is responsible for a person’s mood. It affects perception and sensitivity, and can also transform the range of human sensations. It is because of this rhythm that people tend to change their mood throughout the day. It is responsible for creativity, intuition and the ability to empathize. Women and artistic people are more susceptible to this cycle. Emotional condition, caused by fluctuations in this rhythm, affects family relationships, love, sex.
Physical biorhythm is directly related to the functioning of the human body. It determines internal energy, endurance, reaction speed and metabolism. Reaching its peak, this biological rhythm increases the body's ability to recover. This is of particular importance for athletes and people whose activities involve physical activity.
Change of biorhythms during the day
The most noticeable changes in biological rhythms are observed during full day. They determine favorable hours for work, sleep, rest, learning new information, eating and playing sports. For example, the period from 7 to 8 am is the best time for breakfast, and the time from 16 to 18 o'clock is most suitable for intellectual work.
Human daily biorhythms easily and quickly adapt to time zones. The process of the human body resembles an internal clock. And, as in the case of the transition to winter time, when changing the belt, the body itself “turns the arrows” in the direction it needs.
Indicators of biological rhythms may fluctuate somewhat in favor of the individual characteristics of the human body. In addition, there are several chronotypes that have different circadian rhythms.
Human chronotypes
Based on the nature of daily activity, three types of people are distinguished:
- owls,
- larks,
- pigeons
What is remarkable is that only a small percentage of people are completely chronotypical. The vast majority represent transitional forms between “owls” and “pigeons” and “pigeons” and “larks”.
“Night owl people” usually go to bed after midnight, get up late and are most active in the evening and at night. The behavior of early risers is the opposite: they get up early, go to bed earlier and are more active earlier in the day.
With “pigeons” everything is more interesting. They get up later than early risers, but also go to bed closer to midnight. Their activity is more evenly distributed throughout the day. It is generally accepted that “pigeons” are only an adapted form. That is, people who live with such a biological rhythm simply adapt to their work or study schedule, while the other two chronotypes have their own characteristics from birth.
A sudden change in daily routine can cause deterioration in well-being and uncontrollable mood swings. It will be extremely difficult to combat such a condition, and it will be difficult to restore the normal rhythm of the body’s functioning. Therefore, a clear daily routine is not a luxury, but a way to always be in a good mood.
Biological rhythms of human internal organs
Of particular importance for a person and his health are not only the biological rhythms of the body, but also individual parts. Each organ is an independent unit and works in its own rhythm, which also changes throughout the day.
The time from 1 to 3 am is considered the liver period. From 7 to 9 am the stomach works best. This is why tomorrow is called the most important meal of the day. From 11 to 13 o'clock in the afternoon is the most favorable time for the heart muscle, so training carried out at this time gives greater results. From 15 to 17 hours the urinary tract is most active. Some people note that they experience stronger and more frequent urges to pee during this period of time. Kidney time starts at 5 pm and ends at 7.
Thwart your own work internal organs can be due to poor nutrition, poor sleep patterns, excessive physical and psychological stress.
Methods for calculating biorhythms
If a person knows how his body works, he can plan his work, study and other activities with greater efficiency. Determining health biorhythms is quite simple. The result will be true for all chronobiological types.
To calculate the exact biological cycles of the body, you need to multiply the number of days in a year by age, with the exception of leap years. Then quantity leap years multiply by 366 days. Both resulting indicators are added together. After this, you need to divide the resulting number by 23, 28 or 33, depending on what rhythm you need to calculate.
As is known, each fluctuation in the biological rhythm goes through three stages: a low-energy phase, a high-energy phase and critical days. If you need to know physical state, then it is determined by a 23-day cycle. The first 11 days will be days of good health, greater resistance to stress, and sexual desire. From 12 to 23 days increased fatigue, weakness, bad dream. During this period you need to rest more. Days numbered 11, 12 and 23 can be considered critical.
The 28-day cycle determines emotional indicators. Energy will be high for the first 14 days. This is a favorable time for friendship, love and relationships. The person will be overwhelmed with emotions, all creative abilities will intensify. The period from 14 to 28 will be a time of decline in emotional strength, passivity, and reduced performance. There are only two critical days in the cycle: 14 and 28. They are characterized by the emergence of conflicts and decreased immunity.
The intellectual cycle lasts 33 days. In the first 16 days, the ability to think clearly and clearly, increased concentration, good memory and general mental activity are observed. In the remaining days of the cycle, reactions are slowed down, a creative decline occurs and a decrease in interest in everything. At three o'clok critical days cycle (16, 17, 33) it becomes extremely difficult to concentrate, errors in work appear, absent-mindedness, age, risk of accidents and other incidents due to inattention.
For a faster calculation, you can use the human biorhythm calculator. You can find many different resources on the Internet, where in addition to the calculation applications themselves, you can read reviews real people about them.
Knowledge of the biological rhythms of the body can help a person achieve his goals, harmonize interpersonal relationships and life in general. It will also have a beneficial effect on your physiology and emotional state.
A huge amount of speculation exists around biorhythms. In this article we will talk about biological rhythms with scientific point vision, we learn about what they are, what their nature and role in our life is.
Rhythm is the repetition of an event in a biological system at more or less regular intervals. Biorhythmology, or chronobiology, studies biorhythms. This science studies periodic processes occurring at all levels of organization of living matter: from an individual cell of our body to society as a whole. For billions of years, living organisms have adapted to the conditions of existence, changing the temporary organization of the work of their organ systems. This allowed them to better adapt to changing living conditions, survive and live.
Unity in Diversity
Biorhythms can be divided into several groups:
- according to the temporal characteristics of the rhythm - after what periods certain changes occur;
- according to where this rhythm is observed - in a cell, an organ or the entire organism;
- by rhythm function.
Biological rhythms can cover a very wide range of time periods - from a fraction of a second to tens of years. Periodic changes in the body can be caused either purely external reasons(for example, seasonal exacerbation, well known to doctors chronic diseases), and internal processes (heart rhythm). The first type of biorhythms is called exogenous (external), the second - endogenous (internal).
As a rule, biorhythms can vary extremely in the duration of their period, both in different people and in animals. However, there are four main rhythms, the periods of which practically do not change. They are associated with processes occurring in nature: tides, day and night, phases of the moon, seasons. They retain their periodicity, even if the body is placed outside the influence of periodic factors. Thus, scientists conducted experiments to study the circadian rhythm in humans. A group of volunteers descended into a deep cave so that people could not in any way feel the change of day and night occurring on the surface. Volunteers, provided with everything they needed, had to live in such conditions for about a week.
As a result, it turned out that people maintained the periodicity of sleep and wakefulness. Only this rhythm of activity had a period not of 24 hours, as in a normal day, but of 25 hours.
Rhythms associated with the change of day and night are called circadian, or daily rhythms (circa - translated from Latin as “about”, dies - “day”). The remaining rhythms were called perilunar, peri-tidal and periannual.
Since circadian rhythms play a major role in our lives, all other rhythms were divided in relation to them into ultradian and infradian, that is, into rhythms with a period of less than and more than 24 hours, respectively.
Ultradian rhythms, for example, include rhythms of motor activity and human performance. So. performance (i.e., the effectiveness of performing some work, solving a given task), determined by simple tests such as memorizing incoherent syllables, strongly depends on the time of day. This happens because in different periods the functional state of the nervous system is not the same: periods of “slowness” are replaced by activity, increased sensitivity, increased speed nervous processes- the head is clear, thoughts are clear and definite, any work is in full swing.
Fluctuations in motor activity are associated with the rhythms of activity of the nervous system. IN different time day (during the studies, the influence of sleep and fatigue was excluded), the number of movements performed by a person will vary. After observing yourself, you can find alternating periods of activity and apathy.
Infradian rhythms include the identified three-week periodicity in endocrine system person. The existence of a 21-day rhythm in the dynamics of the production of stress hormones and sexual activity has been proven: testosterone, corticosteroids, adrenaline (with corresponding changes in the functions controlled by these hormones - a periodic increase in sexual activity has been revealed in the majority healthy people after 3 and 7 days).
Of the human infradian rhythms, perhaps the most studied is the cyclical functioning of the female body, the duration of which is approximately equal to lunar month(28 days). During menstrual cycle A complex of rhythmic changes occurs in the female body: body temperature, blood sugar, body weight, etc. physiological indicators. All biorhythms are closely related to each other and constantly interact, influencing each other. For example, doctors are well aware of the modulation of heart contractions by breathing: after a fast run, several slow inhalations and exhalations quickly normalize the heart rate. Hourly rhythms change under the influence of daily rhythms, and daily rhythms change under the influence of annual rhythms.
Why do we need a “biological clock”?
The functions of biorhythms are extremely diverse and very important for the functioning of the body. Transfer of information in some nerve cells depends on changes in the frequency of their impulses; the correct functioning of our heart is ensured by pacemakers; peri-daily, peri-lunar, peri-tidal and peri-annual rhythms serve for maximum adaptation of the body to periodic changes in the environment, to harmonize the processes occurring in the body with the processes of the surrounding world.
By repeating natural cycles in their biorhythms, a person receives a tool for measuring time - the so-called biological clock. Our nature is amazingly rhythmic, amazingly repeatable. This repeatability and predictability of phenomena makes possible life itself, which internalizes this natural rhythm. The biological clock counts not only absolute time- hours and days, but also the very duration of our lives.
In a newborn, sleep and wakefulness alternate every 3-4 hours. All baby biorhythms have the same periodicity. Then there is a gradual adjustment for a period of 24 hours, and with it the determination of the personality type (“night owl”/“lark”).
Our biological rhythms are most stable between the ages of 20 and 50. Then changes begin to occur (“night owls” become similar to “larks” and vice versa), rhythms change their periodicity, failures often occur, and it becomes increasingly difficult for a person to readjust under the influence of external factors. The more regularly our watches run, the higher our chances of longevity.
Daily routine is not a luxury
It is known that the rhythm of a person’s performance is influenced by such factors as motivation, work environment and mental characteristics. Based on the above, we can give some recommendations.
It is important to observe yourself: when you are best at creative work, and when at purely mechanical work, and plan your work day accordingly, setting aside the time when you complete the bulk of the tasks. Of course, we don’t always choose a job according to our wishes; not every job matches our rhythms 100%. However, you should not aggravate this imbalance with your own disorganization. This is why you need at least a rough daily routine. The rhythms of the human body can adapt to external influences - it is only important that they also have a certain periodicity.
How much sleep do you need?
The minimum sleep for an adult is 4.5 hours a day. A long-term decrease in sleep time leads to a significant reduction in performance. Scientists have also shown that prolonged sleep restriction lengthens the time of unrestricted sleep - remember how we get 11 hours of sleep after a hard week of work.
However, it is important to note that people's need for sleep is highly individual. For example, Winston Churchill needed 4 hours of sleep a day and a little sleep in fits and starts during the day, and Albert Einstein loved to sleep - up to 10 hours every day. It should also be remembered that the duration of sleep should be longer during intense work, especially mental work, when nervous overstrain, which include pregnancy. Maintaining wakefulness and sleep patterns sets a normal basis for other biological rhythms.
Biorhythms in medicine
Biological rhythms have great importance in medicine, especially in diagnosis and therapy various diseases, since the body’s reaction to any impact depends on the phase of the circadian rhythm. Thus, when mice are injected with a toxin coli at the end of the resting phase (when all vital signs are reduced) mortality was 80%, and if the injection was carried out in the middle of the activity phase (at increased rates), then the mortality rate was less than 20%.
For humans, the dependence of the action of drugs on the circadian biorhythm has been clearly established. For example, the effect of tooth pain relief is most pronounced in the period from 12 to 18 hours of the day. And the pain sensitivity threshold at this time is one and a half times higher than at night, and numbness as a result of anesthesia lasts several times longer. That is why it is quite reasonable to visit the dentist not early in the morning, but in the afternoon. It can be assumed that labor pain also has a different threshold depending on the time of day. But these phenomena have not yet been studied by scientists.
The study of the rhythms of the human body's sensitivity to drugs marked the beginning of the development of chronopharmacology. Based on knowledge of daily biorhythms, more effective dosage regimens can be developed medicines. For example, the rhythms of blood pressure fluctuations are individual for everyone, and the effect of blood pressure-lowering drugs also depends on the time of day. Knowing these parameters, it is possible to make a more appropriate selection of medications in the treatment of hypertension and coronary heart disease.
To prevent a hypertensive crisis, people predisposed to this should take medications in the evening (it is at this time that a person is most vulnerable).
At bronchial asthma medications Best consumed shortly before midnight; at peptic ulcer- in the morning and in the evening. Circadian (circadian) rhythms must also be taken into account during diagnosis, especially when quantitative indicators are used, such as body temperature, which are also subject to fluctuations during the day. It is necessary that measurements of such indicators are made in the same circadian phase.
In addition to the fact that the biorhythms of our body affect the therapeutic effect of drugs, disturbances in complex rhythms can become the causes of various diseases (dynamic diseases). To correct biorhythms, substances are used that can influence various phases of biological rhythms (chronobiotics). Medicinal plants leuzea and angelica, coffee and tea, eleutherococcus, pine extracts are daytime chronobiotics that act on daily biorhythms; valerian, oregano, hops, peppermint, peony root - night chronobiotics.
About "owls" and "larks"
Now let's look at the rhythms of performance. Undoubtedly, the question of how our performance changes depending on the time of day is very important. The history of studying this problem goes back more than a hundred years, but still much remains unclear, and the conclusions often do not allow making specific recommendations. What is known today? It has been reliably established that performance really depends greatly on the time of day. This addiction can be very different. Thus, in some cases, a morning peak of increased performance and an afternoon decline are noted. On the other hand, Bekhterev believed that in the morning everything mental processes people are slowed down, and in the evening - accelerated. And studies using a test for rapid information processing also found a peak of performance around 21 hours. A study of the performance of schoolchildren who were asked to perform simple arithmetic calculations revealed two peaks of activity: morning (around 11 a.m.) and evening (in the afternoon). A slight decline was observed around 12 am and in the afternoon. It has also been proven that the maximums and minimums of performance also depend on the type of work: purely mechanical performance of some tasks or work requiring intellectual effort. Although short-term memory occurs best in the morning, long-term memory in the best possible way functioned when the material for memorization was presented to students in the afternoon. So information that was memorized in the evening, in a calm environment, is best absorbed.
The above data, however, can in no way indicate the benefits of night vigils - for example, typical for students before a session. Information memorized in this way will very soon evaporate from memory. And attempts to learn six months’ worth of material in a week will lead to a change in the rhythms of performance.
After such a shake-up, it is quite difficult to get back into a rut. After all, a person needs healthy food lasting at least 7 hours a day. However, sometimes this can lead to the emergence of a new, peculiar rhythm - an alternation of “rush work” and “relaxation”.
Most performance rhythms can be divided into three classes:
1) continuous increase in performance throughout most of the day;
2) morning rise, after which a decline occurs;
3) morning maximum performance, a decrease in the afternoon and another peak in the afternoon. As a rule, typical “night owls” and “larks” are characterized by classes 1 and 2 of performance rhythms, while the majority have two performance maximums.
Conceptions by... seasons
There is also no doubt that humans have periannual rhythms. The most interesting data is about conceptions. The figures indicate that the maximum conceptions occur at the end of May - July, but over time the annual fluctuations become less and less pronounced. This happens due to the development of civilization and improvement of living conditions. Most people become less dependent on the weather and annual temperature fluctuations. Thus, scientists believe that the maximum conception occurs at the end of May precisely because by this time the temperature reaches + 18 ° C, which is considered “optimal” for conception (according to researchers).
But with the advent of central heating and the possibility all year round receiving fresh vegetables and fruits, with the creation of a variety of vitamin supplements and other things that make our lives easier, a person’s dependence on external conditions is decreasing. We are witnessing how the development of material culture eliminates the rhythm-forming influence natural factors. Indeed, in addition to temperature, annual rhythms are set by both the length of daylight hours and the composition of sunlight. And with the advent of fluorescent lamps and infrared lamps, we can receive the rays of light and heat we are missing. However, we cannot completely eliminate the influence of natural factors on our life activity, which is confirmed by seasonal mood swings (seasonal depression).
Sleep and biorhythms
Another important indicator of the activity of the human body is our sleep. What is sleep from a scientific point of view, what is its connection with biorhythms?
First of all, it should be noted that sleep is not a passive state that occurs as a result of the cessation of wakefulness, but active process the functioning of certain brain structures. During sleep, the frequency of respiratory movements decreases, the pulse rate decreases, metabolism slows down, and body temperature decreases. This rhythmic fluctuation of physiological parameters is very important for the proper functioning of our body; it determines our health.
There are two phases of sleep - slow and fast (paradoxical). The REM sleep phase is characterized by rapid eye movements (25 times per minute) and brain activity similar to that of a sleepy state. In the first half of the night, deep, slow-wave sleep with short episodes of REM sleep predominates, and in the second half of the night, shallow sleep with significant periods (20-30 minutes) of REM sleep predominates. Up to 5 cycles of sleep phase changes can occur per night. In the first half of the night, a person is dominated by slow, deep sleep. in the second half - shallow sleep with significant periods of REM sleep.
It is during the REM sleep phase that dreams can occur. At this time, the activity of the areas of the brain responsible for the perception of visual images increases: a person does not see anything with his eyes, it is only the memory of the brain, its internal images. Scientists believe that dreams are a physiologically useful process that maintains the functional state of the nervous system, clearing the memory of unnecessary things. The frequency of dreams may increase during illnesses, complex life situations associated with increased nervous tension. The famous physiologist Sechenov called dreams “unprecedented combinations of experienced impressions.” The active work of the brain does not stop at night; it is only transferred from the conscious to the subconscious, which combines the events of the day in its own way. Therefore, in the morning we sometimes find successful solutions to problems that troubled us the day before. There is a hypothesis that we dream every night, but remember only a small part.
The alternation of periods of sleep and wakefulness is one of the most important human rhythms; it largely determines our state of health. So, it is during sleep, in its first hours, that growth hormone is released into the blood. In the waking state, its level is usually low. The release of this hormone also occurs during the afternoon nap. This is why it is so important to observe a daily routine for children; it is not without reason that they say that small children grow up in their sleep.
Finally, I again want to focus the attention of readers, especially expectant mothers, on two important principles - self-observation and daily routine. Remember that all activity and performance curves constructed by scientists are averaged, generalized from observations large groups volunteers. Only through self-observation can you determine your own rhythms, individual fluctuations in mood and activity, and try to adapt your daily routine as much as possible to these rhythms. People can work even on night shifts - their rhythms are adjusted, but here, too, regularity and periodicity are most important.
Only in this case can the body, its cells and tissues adapt to a certain routine, and the internal clock fulfill its role: count down the time allotted to us for a full and healthy life.
