Self-regulation in biology is ... The concept of self-regulation of living systems

Self-regulation in biology is one of the most important properties of a living system, consisting in the automatic installation and maintenance of a certain level of parameters necessary for normal functioning. The essence of the process is that no external influences become managers. The factors that guide change are formed within the self-regulating system and contribute to the creation of a dynamic equilibrium. The processes that arise during this process can be cyclical, dampening and resuming as certain conditions collapse or disappear.

Self-regulation: the meaning of the biological term

Any living system, from the cell to the biogeocenosis, is constantly exposed to outside factors. Temperature conditions change, humidity, food finishes or inter-species competition becomes tougher - examples can be mass. In this case, the viability of any system depends on its ability to maintain the consistency of the internal environment (homeostasis). It is to achieve this goal and there is self-regulation. The definition of the concept implies that changes in the external environment are not immediate factors of influence. They are converted into signals that cause this or that imbalance and lead to the launch of self-regulation mechanisms designed to return the system to a stable state. At each level, this interaction of factors looks different, so to understand what self-regulation is, let us dwell on them in more detail.

Levels of organization of living matter

Modern natural science adheres to the concept that all natural and social objects are systems. They consist of separate elements, constantly interacting according to some laws. Live objects are not an exception to this rule, they are also systems with their internal hierarchy and multi-level structure. And the structure has one interesting feature. Each system can simultaneously represent an element of a higher level and be a collection (that is, all the same system) of levels of a lower order. For example, a tree is an element of a forest and at the same time a multicellular system.

In order to avoid confusion, in biology it is customary to consider four basic levels of living organization:

• Molecular-genetic;
• Ontogenetic (organism - from the cell to the person);
• Population-specific;
• Biogeocenotic (ecosystem level).

Methods of self-regulation

The processes occurring at each of these levels are externally distinguished by the scale, the energy sources used and their results, but they are similar in essence. They are based on the same methods of self-regulation of systems. First of all, this is the feedback mechanism. It is possible in two versions: positive and negative. Recall that direct communication involves the transfer of information from one element of the system to another, the reverse proceeds in the opposite direction, from the second to the first. In this case, both of them change the state of the receiving component.

Positive feedback leads to the fact that the processes, about which the first element informed the second, are fixed and continue to be carried out. Such a process underlies any growth and development. The second element constantly signals the former to continue the same processes. At the same time, the stability of the system is disturbed.

The main mechanism

Otherwise, negative feedback operates . It leads to the appearance of new changes, the opposite of those about which the first element informed the second. As a result, processes that violate the equilibrium are eliminated and terminated, and the system again becomes stable. A simple analogy is the operation of the iron: a certain temperature is a signal for turning off the heating element. Negative feedback is at the heart of all the processes associated with maintaining homeostasis.

All-embracing

Self-regulation in biology is a process that permeates all the levels mentioned. Its purpose is to preserve the dynamic equilibrium, the constancy of the internal environment. Because of the all-embracing process, self-regulation lies at the center of many sections of natural science. In biology, this is cytology, the physiology of animals and plants, and ecology. Each of the disciplines deals with a separate level. Let us consider what self-regulation is, at the basic stages of the organization of the living.

The intracellular level

In each cell, chemical mechanisms are mainly used to maintain a stable equilibrium of the internal environment. Among them, the main role in regulation is played by the control of genes, on which the production of proteins depends.

The cyclic nature of the course of processes can be easily traced through the example of enzyme chains suppressed by the final products. The purpose of the activity of such formations in the processing of complex substances into simpler ones. The final product is similar in structure to the first enzyme in the chain. This property plays a key role in maintaining homeostasis. The product binds to the enzyme and suppresses its activity as a result of a strong change in structure. This occurs only after the concentration of the final substance has exceeded the permissible level. As a result, the fermentation process stops, and the finished product is used by the cell for its own needs. After a while, the level of the substance falls below the allowable value. This is the signal for starting fermentation: the protein is detached from the enzyme, the inhibition of the process stops and everything starts again.

Increasing complexity

Self-regulation in nature is always based on the principle of feedback and generally proceeds according to a similar scenario. However, at each next level, factors that complicate the process appear. For the cell, the constancy of the internal environment is important, maintaining a certain concentration of various substances. At the next level, the process of self-regulation is designed to solve many more problems. Therefore, multicellular organisms appear whole systems that support homeostasis. These are the organs of respiration, discharge, circulation, and the like. The study of the evolution of the animal and plant world easily makes it clear how, as the structure and external conditions become more complicated, the mechanisms of self-regulation are improved.

Organism level

The consistency of the internal environment is best maintained in mammals. The basis for the development of self-regulation and its implementation is a nervous and humoral system. Constantly interacting, they control the processes occurring in the body, contribute to the creation and maintenance of dynamic equilibrium. The brain receives signals from the nerve fibers present in every part of the body. Information flowing from the endocrine glands also flows down here. The interconnection of nervous and hormonal regulation contributes to the often almost instantaneous restructuring of ongoing processes.

Feedback

The work of the system can be traced on the example of maintaining blood pressure. All the changes in this indicator are captured by special receptors located on the vessels. The increase or decrease in pressure affects the stretching of the walls of the capillaries, veins and arteries. It is to these changes and receptors react. The signal is transmitted to the vascular centers, and from them proceed "instructions", how to correct the tone of the vessels and cardiac activity. The system of neurohumoral regulation is also connected . As a result, the pressure returns to normal. It is easy to see that the same feedback mechanism lies at the heart of the harmonious work of the regulatory system.

At the head of all

Self-regulation, the determination of certain adjustments in the activity of the organism, lies at the basis of all changes in the body, its reactions to external stimuli. Stress and permanent loads can lead to hypertrophy of certain organs. An example of this is the developed muscles of athletes and increased lungs of fans of freediving. Stress is often a disease. Hypertrophy of the heart is not uncommon in people diagnosed with obesity. This is the body's response to the need to increase the burden of blood pumping.

Mechanisms of self-regulation lie in the basis of physiological reactions that occur during fright. In the blood, a large amount of the adrenaline hormone is released, which causes a number of changes: increased oxygen consumption, increased amounts of glucose, increased heart rate and mobilization of the muscular system. In this case, the overall balance is maintained due to the repayment of the activity of other components: digestion slows down, sexual reflexes disappear.

Dynamic balance

It should be noted that homeostasis, at whatever level it is maintained, is not absolute. All parameters of the internal environment are maintained within a certain range of values and constantly oscillate. Therefore, they speak of a dynamic equilibrium of the system. It is important at the same time that the value of a particular parameter does not go beyond the so-called oscillation corridor, otherwise the process may become pathological.

Sustainability and self-regulation of the ecosystem

Biogeocenosis (ecosystem) consists of two interconnected structures: a biocenosis and a biotope. The first is the whole set of living beings of a given area. Biotopes are the factors of the inanimate environment where biocenosis resides. Environmental conditions that permanently affect organisms are divided into three groups:

• Abiotic environmental factors: temperature, light, humidity and other elements of inanimate nature;
• Biotic environmental factors: the influence of some organisms on others, are divided into competition, symbiosis, parasitism and predation;
• Anthropogenic environmental factors - human impact.

Preservation of homeostasis means the well-being of organisms in conditions of constant exposure to the external environment and changing internal factors. Supportive biogeocenosis self-regulation is primarily based on the system of trophic connections. They are a relatively closed chain through which energy flows. Producers (plants and hemobacteria) receive it from the sun or as a result of chemical reactions, create with its help an organic substance consumed by consumers (herbivores, predators, omnivores) of several orders. At the last stage of the cycle are decomposers (bacteria, some types of worms) that decompose organic matter into its constituent elements. They are again introduced into the system as food for the producers.

Constancy of the cycle is ensured by the fact that on each level there are several kinds of living beings. If one of them falls out of the chain, a substitution is made for a similar function.

External influence

Maintaining homeostasis is accompanied by constant exposure from the outside. Changes around the ecosystem conditions lead to the need to adjust internal processes. There are several criteria for sustainability:

• High and balanced reproductive potential of individuals;
• Adaptation of individual organisms to changing environmental conditions;
• Species diversity and branched food chains.

These three conditions help maintain the ecosystem in a state of dynamic equilibrium. Thus, at the level of biogeocenosis, self-regulation in biology is the reproduction of individuals, the preservation of numbers and resistance to environmental factors. In this case, as in the case of a separate organism, the equilibrium of the system can not be absolute.

The concept of self-regulation of living systems extends the described patterns to human communities and social institutions. Its principles are widely used also in psychology. In fact, this is one of the fundamental theories of modern natural science.