The science that studies rhythm in biology arose at the end of the 18th century. Its founder is a German doctor Christopher William Gufeland. From its submission, the biological rhythms of the body were considered to be dependent exclusively on external cyclic processes, primarily on the rotation of the Earth around the Sun and its own axis. Today, chronobiology is popular. According to the theory that dominates it, the causes of biorhythms lie both outside and inside a specific organism. Moreover, changes that are repeated over time are not unique to individual individuals. They permeate all levels of biological systems - from cells to the biosphere.
Rhythm in Biology: Definition
Thus, the considered property is one of the fundamental characteristics of living matter. Rhythm in biology can be defined as fluctuations in the intensity of processes and physiological reactions. It is a periodic change in the state of the environment of a living system that occurs under the influence of external and internal factors. They are also called synchronizers.
Biorhythms that are independent of external (acting on the system from the outside) factors are endogenous. Exogenous, respectively, do not respond to the impact of internal (operating within the system) synchronizers.
Causes
As already noted, in the first stages of the formation of a new science, rhythm in biology was considered to be caused only by external factors. This theory was replaced by the hypothesis of internal determination. An insignificant role was assigned to external factors in it. However, quickly enough, researchers came to understand the high importance of both types of synchronizers. Today it is believed that biological rhythms of life, endogenous in nature, are subject to changes under the influence of the external environment. This idea is at the center of the multio-oscillatory model of regulation of such processes.
The essence of the theory
According to this concept, endogenous genetically programmed vibrational processes are affected by external synchronizers. A huge number of internal rhythmic vibrations of a multicellular organism are arranged in a certain hierarchical order. At the heart of its maintenance are neurohumoral mechanisms. They coordinate the phase relationships of different rhythms: unidirectional processes occur synchronously, and incompatible ones work in antiphase.
It is difficult to imagine all this activity without a certain oscillator (coordinator). In the theory under consideration, three interrelated regulatory systems are distinguished: the pineal gland, pituitary gland and adrenal glands. The pineal gland is considered the most ancient.
Presumably in organisms at the lower stages of evolutionary development, the pineal gland plays a major role. The melatonin secreted by it is produced in the dark and disintegrates in the light. In fact, it tells all cells about the time of day. With the complexity of the organization, the pineal gland begins to play a second role, giving precedence to the suprachiasmatic nuclei of the hypothalamus. The question of the relationship in the regulation of biorhythms of both structures has not been fully resolved. In any case, according to the theory, they have an “assistant” - the adrenal glands.
Kinds
All biorhythms are divided into two main categories:
physiological are fluctuations in the functioning of individual body systems;
ecological, or adaptive, are necessary to adapt to constantly changing environmental conditions.
Also common is the classification proposed by the chronobiologist F. Hallberg. He took their duration as the basis for the separation of biological rhythms:
high frequency fluctuations - from a few seconds to half an hour;
average frequency fluctuations - from half an hour to six days;
low frequency fluctuations - from six days to a year.
The processes of the first type are breathing, palpitations, electrical activity of the brain and other similar rhythms in biology. Examples of medium-frequency fluctuations are changes during the day of metabolic processes, sleep patterns and wakefulness. The third type of vibrations includes seasonal, annual, and lunar rhythms.
External synchronizers in relation to a person are divided into social and physical. The first is the daily routine and various norms adopted at work, in everyday life or in society as a whole. Physical synchronizers are represented by the change of day and night, the intensity of electromagnetic fields, fluctuations in temperature, humidity and so on.
Desync
An ideal state of an organism arises when a person’s internal biorhythms work in accordance with external conditions. Unfortunately, this is not always the case. The state when there is a mismatch of internal rhythms and external synchronizers is called desynchronosis. It also exists in two versions.
Internal desynchronosis is a mismatch of processes directly in the body. A common example is a violation of the rhythms of sleep and wakefulness. External desynchronosis is a mismatch of internal biological rhythms and environmental conditions. Such violations occur, for example, when flying from one time zone to another.
Desynchronosis manifests itself in the form of changes in physiological parameters such as blood pressure. Often it is accompanied by increased irritability, lack of appetite, rapid fatigue. According to chronobiologists, as mentioned above, any disease is the result of a mismatch of certain oscillatory processes.
Daily biological rhythms
Understanding the logic of fluctuations of physiological processes allows you to optimally build activity. In this sense, biological rhythms lasting about a day are especially important. They are used both to determine the effective mode of work and rest, and for medical diagnosis, treatment, and even the choice of dose of drugs.
In the human body, a day is a period of oscillation of a huge number of processes. Some of them change significantly, others - minimally. It is important at the same time that the indicators of both those and others do not go beyond the norm, that is, they do not become threatening to health.
Temperature fluctuations
Thermoregulation is the key to the constancy of the internal environment, and therefore, the proper functioning of the body for all mammals, including humans. The temperature changes during the day, while the range of fluctuations is quite small. The minimum indicators are characteristic for the period from one in the morning to five in the morning, the maximum are recorded around six in the evening. The amplitude of the oscillations in this case is usually less than one degree.
Cardiovascular and endocrine systems
The work of the main “motor” of the human body is also subject to fluctuations. There are two time points at which the activity of the cardiovascular system decreases: one in the afternoon and nine in the evening.
Their rhythms are also characteristic of all organs of blood formation. The peak bone marrow activity occurs in the early morning, and in the spleen at eight in the evening.
Hormone secretion is also unstable throughout the day. The concentration of adrenaline in the blood rises in the early morning and reaches its peak by nine o’clock. This feature explains the vivacity and activity, which are most often characteristic of people in the morning.
Curious statistics are known to midwives: labor in most cases begins around midnight. It is also associated with the features of the endocrine system. By this time, the posterior pituitary gland is activated, producing the corresponding hormones.
In the morning - meat, in the evening - milk
For adherents of proper nutrition, facts related to the digestive system will be curious. The first half of the day is the time when the motility of the gastrointestinal tract increases, the production of bile increases. The liver actively consumes glycogen in the morning and gives off water. From these patterns, chronobiologists derive simple rules: it is better to eat heavy and fatty foods in the morning, and after lunch and evening, dairy products and vegetables are ideal.
Operability
It's no secret that human biorhythms affect his activity during the day. Oscillations in different people have features, but general patterns can be distinguished. Three "bird" chronotypes that connect biological rhythms and performance, perhaps, are known to all. These are the “lark”, “owl” and “dove”. The first two are extreme options. "Larks" are full of strength and energy in the morning, they get up easily and go to bed early.
"Owls", like their prototype, are nocturnal. The active period for them begins at about six in the evening. Early rise is very difficult for them to bear. "Pigeons" are able to work both day and evening. In chronobiology they are called arrhythmias.
Knowing your type, a person can more effectively manage their own activities. However, there is an opinion that any “owl” can become a “lark” if desired and perseverance, and the division into three types is more likely due to habits, rather than inherent features.
Constant change
Biorhythms of man and other organisms are not rigid, forever fixed signs. In the process of ontogenesis and phylogenesis, that is, individual development and evolution, they change with certain laws. What is responsible for such shifts is still incomprehensible. There are two main versions in this regard. According to one of them, changes are guided by a mechanism laid down at the cellular level - it can be called a biological clock.
Another hypothesis gives the main role in this process to geophysical factors that have yet to be studied. Adherents of this theory explain the differences in individual biorhythms by their position on the evolutionary ladder. The higher the level of organization, the more intense the metabolism. Moreover, the nature of the indicators does not change, but the amplitude of the oscillation increases. They consider the very rhythm in biology and its synchronization with geophysical processes as the result of natural selection, leading to the transformation of the external (for example, the change of day and night) into the internal (period of activity and sleep) rhythm fluctuation.
Age effect
Chronobiologists were able to establish that in the process of ontogenesis, depending on the stage passed by the body, circadian rhythms change. Each period of postnatal development corresponds to its own oscillations of internal systems. Moreover, the change in biological rhythms is subject to a certain regularity described by the Russian specialist G.D. Gubin. It is convenient to consider it as an example of mammals. In them, such changes are primarily associated with amplitudes of circadian rhythms. From the first stages of individual development, they increase and reach a maximum in young and mature age. Then the amplitudes begin to decrease.
These are not the only rhythm changes associated with age. The sequences of acrophases (acrophase - the point in time when the maximum value of the parameter is observed) and the range of the age norm (chronodesma) also change. Given all these changes, it becomes obvious that it is precisely in adulthood that biorhythms are perfectly coordinated and the human body is able to withstand various external influences while maintaining its health. The situation changes over time. As a result of the mismatch of various rhythms, the health reserve gradually runs out.
Chronobiologists suggest using similar patterns to predict disease. On the basis of knowledge about the peculiarities of fluctuations in human circadian rhythms throughout life, it is theoretically possible to construct a certain graph that reflects the health reserve, its maximums and minimums in time. Such testing is a matter of the future, according to most scientists. However, there are theories that allow you to build something similar to such a schedule now.
Three rhythms
Let's open a little curtain of secrets and tell about how to define your biorhythms. The calculation in them is based on the theory of psychologist Herman Freedom, physician Wilhelm Fiss and engineer Alfred Telcher, which they created at the turn of the 19th and 20th centuries. The essence of the concept is that there are three rhythms: physical, emotional and intellectual. They arise at the time of birth and throughout life do not change their frequency:
physical - 23 days;
emotional - 28 days;
intellectual - 33 days.
If you build a graph of their changes over time, it will take the form of a sinusoid. For all three parameters, the part of the wave above the Ox axis corresponds to a rise in indicators; below it is a zone of decline in physical, emotional and mental capabilities. Biorhythms, which can be calculated according to a similar schedule, at the point of intersection with the axis signal the beginning of a period of uncertainty, when the body's resistance to environmental influences greatly decreases.
Definition of indicators
Calculation of biological rhythms based on this theory can be done independently. To do this, you need to calculate how much you have already lived: multiply age by the number of days in a year (do not forget that there are 366 in a leap year). The resulting figure must be divided by the frequency of the biorhythm whose graph you are building (23, 28 or 33). Get some integer and remainder. Multiply the whole part again by the duration of a specific biorhythm? f subtract the obtained value from the number of days lived. The balance will be the number of days of the period at the moment.
If the obtained value does not exceed one fourth of the cycle duration, this is the rise time. Depending on the biorhythm, it involves vigor and physical activity, good mood and emotional stability, creative inspiration and intellectual recovery. A value equal to half the length of the period symbolizes the time of uncertainty. Getting into the last third of the duration of any biorhythm means being in the zone of decline in activity. At this time, it is common for a person to get tired faster, the danger of diseases increases, when it comes to the physical cycle. In emotional terms, there is a decrease in mood up to depression, a deterioration in the ability to restrain strong internal impulses. At the level of intelligence, the recession period is characterized by difficulty in making decisions, a certain retardation of thought.
Attitude to theory
In the scientific world, the concept of three biorhythms in this format is usually criticized. There is no sufficient basis for the assumption that in the human body something can be so unchanged. This is evidenced by all the discovered patterns that govern rhythm in biology, the characteristics of internal processes inherent in different levels of living systems. Therefore, the described calculation methodology and the whole theory are most often proposed to be considered as an interesting pastime, but not a serious concept, on the basis of which it is worth planning your activities.
The biological rhythm of sleep and wakefulness, therefore, is not the only one that exists in the body. Vibrations affect all systems that make up our body, and not only at the level of such large formations as the heart or lungs. Rhythmic processes are embedded in the cells, and therefore are characteristic of living matter as a whole. The science that studies such vibrations is still young enough, but already seeks to explain many of the laws that exist in human life and in all nature. Already accumulated data suggest that the potential of chronobiology is actually very high. Perhaps in the near future, doctors will also be guided by its principles, prescribing doses of drugs in accordance with the characteristics of the phase of a biological rhythm.