Rhythmicity in biology is ... The coefficient of rhythm

Rhythmicity in biology is a very interesting phenomenon. A lot of scientists are now studying this phenomenon. Rhythmicity in biology is a universal process involving all living organisms. You will see this in this article after reading this article.

The principle of the unity of the environment and the organism is one of the principles of modern natural science. All living organisms, as well as superorganisms, forming a unity with the environment in which they live, have the rhythm of all their processes. Their vital activity is subject to periodic rhythms, which reflect reactions to the rhythms of the whole universe (geophysical, astronomical), as well as nature.

P.Ya. Sokolov, a Russian sociologist, notes that the entire animal and plant world, and with it man, constantly and eternally experiences the effects of the physical world and responds with rhythmic pulsating reactions to the beating of the world's pulse.

What are biological rhythms?

Let us consider the concept of interest in more detail. Biological rhythms are periodically recurring changes in the nature and intensity of biological phenomena and processes. These periodic processes have a wide frequency range. They occur at each level of the organization of living systems. The more complex the biosystem, the more it has more biorhythms. They are fixed at the genetic level. Rhythmicity in biology is a phenomenon that is very important for the adaptation and natural selection of organisms.

Its presence is due to the synchronization of biochemical processes. Since a living organism is a hierarchical system, it needs to balance its functioning with the synchronization of different subsystems and levels not only in time, but also in biological space.

In this article you will learn in detail about what is rhythm in biology. Manifestations, properties, examples will also be considered below.

Chronobiology: the emergence and development

Science, which studies biorhythms, is called chronobiology. It is well known since ancient times that the petals and leaves of plants, depending on the time of day, make certain movements. Karl Linnaeus in 1745 invented the "flower clock" (pictured below), allowing you to determine the time for the opening and closing of flowers.

In the first half of the 19th century, the first studies of circadian rhythms were already carried out in humans, such as body temperature, frequency of urination and heartbeat. In textbooks on the physiology of this period, there are indications of the existence of rhythmic functions that are endogenous, that is, arise in the body itself. In 1936, the endogenous character of the daily rhythms of plants and flowers was finally established. To do this, any external influences on them were excluded.

Other milestones in the development of the science of chronobiology are the discovery of the orientation of birds and bees in flight by the sun, confirmation of the presence in the human body of endogenous circadian rhythms. A new impetus to this science was given as a result of the exploration of the cosmos. As before, the main interest of scientists in the study of biological rhythms is the study of annual, lunar and diurnal rhythms.

Rhythms physiological and adaptive

The following are their classifications from the point of view of the interaction of the environment and the organism.

1. Adaptive rhythms (biorhythms) are oscillations occurring with periods close to the most important geophysical cycles. Their role is to adapt different organisms to changes in the external environment that periodically occur. Their frequency is stable.
2. Rhythms physiological (working) - fluctuations, which reflect the activity of physiological systems of this or that organism. Their frequency varies considerably and depends on the state of the organism.

Rhythms exogenous and endogenous

Rhythms by the nature of origin are divided into exogenous and endogenous. Exogenous - the body's response to changes in the environment. Endogenous ones arise as a result of the action of self-regulating processes, characterized by delayed feedback. They are subject to external influences, which can affect their amplitude, and also shift the phase of biorhythms.

Rhythms by levels of organization of the biosystem and frequency

Rhythms are also divided according to the levels of organization of a particular biosystem. They are subdivided into biospheric, population, organism, organ and cellular.

By frequency they are:

• Rhythms of high frequency (from one fraction of a second to 30 minutes);
• Average (from 30 minutes to 28 hours);
• Mesorhythms (from 28 hours to 7 days);
• Macro-rhythms (from 20 days to a year);
• Megarhtms (periodicity - dozens of years).

Nature of biorhythms

A living organism, according to the most common hypothesis, is an independent oscillatory system, characterized by a set of rhythms, internally related. Cycles of metabolism (catabolism and metabolism) occur in cells continuously. These are complexes of various biochemical reactions - synthesis and cleavage of substances. In cells, therefore, in accordance with the metabolic cycles, the concentrations of various substances (metabolic products, enzymes, matrix and transport RNA, etc.) that participate in biochemical reactions continuously change continuously. The parameters of the internal environment of the biosystems as a result of these reactions perform continuous oscillations, deviating from the mean values.

In living organisms, sensors that determine the nature and speed of metabolic processes are allosteric hormones and modulators that support rhythm in biology. This they continuously monitor the state of the body. And he seeks to maintain the constancy (homeostasis) of the internal environment - pH, temperature, osmotic pressure, concentration of substances, etc. Many mechanisms are involved in maintaining homeostasis. They are built mainly on the principle of feedback. For example, an excess of glucose in the blood triggers the storage mechanism of this substance (in the form of glycogen). On the contrary, its deficiency leads to an increased cleavage of glycogen.

The following can be deduced from this. In living organisms, no process is continuous. It must necessarily alternate with the directed opposite: work with rest, inhale with exhalation, synthesis with splitting, wakefulness with sleep, etc. The state of a living organism, therefore, can not be static. It is characterized by such a concept as rhythm. The presence of this property of a living organism can be determined even by simple observation. You may notice that some (and in fact everything) its energy and physiological parameters are always in a state of oscillation both in amplitude and frequency relative to the mean values.

Such fluctuations are biorhythms. With the help of these living organisms ensure the stability of its thermodynamic state. It allows you to successfully adapt to the environment, its cyclic changes is precisely rhythm. The definition of this phenomenon was given at the beginning of this article.

Internal clock

An external time sensor is not necessary for system synchronization at a high degree of conjugation of all its subsystems. In the process of the development of the organism, the innate program of ordering of functions in time is modified, allowing it to adapt to the temporal profile of the environment. Such an organism is able to "predict" the time of day. This allows him to connect in advance various effectors, which are not included in the response immediately. For example, body temperature, as well as plasma levels of corticosteroids in normal sleep, begin long before its end. Therefore, awakening sometimes occurs earlier than light turns on.

Here are other examples of rhythm. Only those organisms survived in the process of natural selection, which possessed the ability not only to catch various changes in natural conditions, but also to adjust their rhythmic apparatus to the rhythm of external oscillations. For example, animals alternate the rhythms of wakefulness and sleep so that it contributes to providing favorable conditions for the extraction of food. In nature, reproductive systems (periods of infertility and fertility) are also adapted to environmental conditions that are the most optimal for growing offspring. Many birds fall to the south in the fall. This is one example of how rhythm is manifested. Biology knows many other examples. So, some animals fall into hibernation. This helps them survive, despite the fact that external environmental conditions are extreme.

Daily biorhythms

Circadian rhythm in biology - what is it? Let's figure it out. Daily (circadian) biorhythms include such phenomena and changes in the nature and intensity of biological processes, the frequency of recurrence of which is 24 ± 4 hours. Most physiological and biochemical processes of metabolism, movement, development, growth are subject to these rhythms, which are caused by the circadian (daily) rhythm of the environment. It, in turn, is connected with rotation around its axis of our planet. Examples of such processes: the intensity of metabolism, fluctuations in body temperature, the frequency of cell division. For all of them, the daily rhythmicity is characteristic.

Biology is a science that studies not only animals but also plants. In the latter, in particular, rhythmic cycles of lowering the leaves and closing the flowers are observed at night. In the daytime they are revealed. The rhythms are preserved even when there is no sunlight. This was confirmed by his experiments. Shnol, the Russian biophysicist. He gave Maran beans as an example. Her leaves rose and fell in the morning and evening, even if the plant was in a dark room. It seemed to feel the time and determined the internal physiological clock.

Plants usually determine the duration of the day for the transition from one form to another of the phytochrome pigment when the characteristics of sunlight (its spectral composition) change. For example, the sun at sunset has a red color because red light has the longest wavelength and less than blue, dissipates. In the twilight or the setting sun, a lot of infrared and red radiation. This is perceived by plants, showing a daily rhythm.

Biology is a science in which, for the time being, a great deal of experience in observing various animals has been accumulated. It was found, in particular, that the alternation of periods of rest and activity of animals (night and day) also refers to the daily rhythms. For them it is important to determine the time is not absolute, but relative. They need to know when the sun rises and sits, as the day-time beings use the light part of the day to search for food, and the nightly ones - the dark one.

Let's give an example - consider the daily rhythm of an inviting crab on the coast of the Atlantic Ocean. He changes his color, showing a daily rhythm. Biology is a science that, like others, reveals patterns. Why does the crab change its color? Let's figure it out.

The crab is lighter in the morning, but when the sun rises higher above the horizon, it becomes darker. Playing a protective role, the pigment protects the inviting crab from the scorching sun rays. If there is an outflow, it is helped by a darker color to remain unnoticed on the coastal sand. Namely, there is a crab sent to search for food.

Daily rhythms in humans

About 300 physiological functions that have diurnal rhythms are observed in the human body. Body weight, based on the human circadian system, is maximum at 18-19 hours, respiratory rate - at 13-16 hours, heart rate - at 15-16 hours, blood level in red blood cells - at 11-12 hours, leukocytes - at 21 -23 hours, etc.

Mental processes accelerate in the evening and slow down in the morning. The rhythms of mental and physiological functions, in turn, are affected by changes in wakefulness and sleep, rest and activity. The parameters of the working capacity curve depend on a variety of factors during the waking period: from the level of motivation, food intake, the general situation, the type of personality, etc.

The term "desynchronosis" denotes a violation in the biological system of temporal ordering of rhythms. The study of its mechanisms is of great importance in the organization of labor and recreation of personnel, while carrying out various preventive measures aimed at protecting health. Desynchroz, in particular, is observed in individuals who traveled a long distance (in 4-5 time zones), with a change in the mode of operation from day to night, as well as from astronauts in the performance of space flights.

Lunar biorhythms

Circular (lunar) biorhythms - rhythms, the period of which averages 29.53 days. These rhythms in biology correspond to the lunar-monthly cycle, that is, the cycle of the phases of the moon.

Many geophysical processes are affected by the periodicity of the Moon's rotation around our planet. For example, night illumination, temperature, air pressure, magnetic fields of the Earth, wind direction change . All these phenomena for circus rhythms are temporary indicators.

Marine organisms have the most impressive examples of how these rhythms affect life processes. For example, Palolo, a marine worm that inhabits coral reefs, in October and November, in the final decade of the lunar cycle and at the same time during the day, separates its rear part, which is filled with the products of the reproductive system, into the water. This is necessary for the continuation of the family.

Lunar cycles of fertility and fertility periods can be not only synodic (as in the previous example). There are also syzyges with an interval of 14.7 days. So, one species of fish that live on the shores of the California Bay, on a full moon and new moon (during high tide) lays eggs on the beach. It develops for 14 days on the shore and enters the water with the next tide.

Moonlight, as we have already mentioned, causes differences in illumination at night. This contributes to the fact that the activity of animals that lead an evening or night way of life is changing. Even if you exclude the impact of moonlight in the laboratory, the frequency of circulary processes is preserved. It can be caused by other factors associated with the lunar cycle. For example, this is the oscillation of the magnetic field of our planet.

The lunar cycle also affects the growth of plants. This can be shown by the example of fluctuations in the yield of radish, potatoes and legumes. For a long time lunar calendars have been used to help determine the optimal time for agrotechnical measures and planting plants.

Annual biorhythms

Circulatory (annual) biorhythms in biology have an oscillation period of 1 year ± 2 months. They are associated with the rotation around the Sun of our planet.

These rhythms are observed in all organisms, from the tropical to the polar zone. Their expression grows as the latitude increases. The analysis of rhythmicity allowed scientists to conclude that in organisms inhabiting polar and temperate zones in which seasonal differences are most noticeable, it manifests itself distinctly. The basis of annual biorhythms is, first, adaptive reactions that arise in response to changes in the most important parameters of the environment (water regime, quantitative and qualitative composition of food, temperature).

Secondly, it is the body's response to the signaling factors of the environment (for example, changes in the intensity of the geomagnetic field, photoperiod, the appearance of certain chemical components). There are annual biorhythms, for example, in the phenomena of migrations, migrations, summer and winter hibernation, reproductive processes, etc.

To many animals, hibernation helps to survive an unfavorable period. Surprisingly, the animals determine the time for it. Bear, for example, always fits in its den on the eve of a snowfall. And he sleeps after that until April, until the temperature is 12 ° C (that is 5.5 months). At this time, it exists due to the fat accumulated since the fall. His stock is almost a third of the total body weight of the animal. The temperature of the bear's body during hibernation decreases by approximately 10 ° C, the frequency of its breathing decreases 3 times. This helps to save the life resources accumulated in a warm time. This is the rhythm of the bear's body. If the rhythm is broken, and the beast does not lie down in the den for some reason or suddenly wakes up in the middle of winter, it is almost doomed to perish. The rod will overcome a lot of parasites, which are rapidly developing in the weakened organism, which suffers from hunger.

So, numerous examples of rhythmicity were presented in this article. They confirm that this is a universal phenomenon in the animal world. Biorhythms, moreover, are the determining factor of the existence of living organisms. The principle of rhythmicity is found at all levels of the organization of biosystems. It serves to adapt the body for better functioning in the environment.

Coefficient

So, we have considered the rhythm in biology, what it is, you now know. However, the concept of interest to us is found not only in this science. In particular, economists have concluded that it is also observed in the production sector. Having made this discovery, they introduced the concept of "coefficient of rhythm". He always tends to unity. As a rule, the rhythmic coefficient is determined for a day, a decade, a month, etc. With it, one can characterize, in particular, the degree of use of working time in the production process. The higher the rate of rhythm, the more the production cycle is denser, and the economic resources (mainly working time) are spent more rationally.