In order for the body to fully function, it must constantly adapt to the changes that occur in the world around us and inside it. This process is called compensatory-adaptive reactions. More about its varieties, stages, stages and features of the violation later in the article.
The concept of compensation, reaction and mechanism
To freely navigate and understand this problem, one should distinguish between the concepts of compensation in general, compensatory-adaptive reactions and compensatory mechanisms.
In a broad sense, "compensation" is a physiological property of the body, the main purpose of which is to restore its internal constancy for the further implementation of its normal functions. Regardless of the characteristics of external stimuli (pain, temperature and others), compensation mechanisms are universal. There are only minor differences in the speed of inclusion of compensation, the degree of inclusion inwork of higher nerve centers (cerebral cortex) and so on.
Compensatory-adaptive reactions of the organism are the primary shifts in its work, which are aimed at the complete elimination or weakening of impaired functions due to exposure to extreme environmental conditions.
Compensatory mechanisms are a sequence of changes in the body that occur quickly and dynamically replace each other. They develop at various levels - from a molecule to a whole organism.
Main varieties
Depending on the level of development of the corresponding changes, the following types of compensatory-adaptive reactions are distinguished:
- Intracellular - changes occur inside the cell due to the stress of the function of its elements (mitochondria, lysosomes, Golgi apparatus, etc.).
- Tissue - the development of changes at the tissue level.
- Organ - changing the function of a single organ.
- Systemic - the occurrence of adaptive reactions at the level of several organs that are part of one system (respiratory, cardiovascular, digestive, etc.).
- Intersystem - changes in a number of organ systems at once up to the whole organism.
The most common types of compensatory-adaptive reactions in clinical practice, depending on the nature of the changes that occur in certain structures:
- regeneration;
- atrophy;
- hypertrophy;
- hyperplasia;
- metaplasia;
- tissue rearrangement;
- organization;
- dysplasia.
Some species are described in more detail in the relevant sections.
Development stages
There are three stages in the development of compensatory-adaptive reactions:
- becoming;
- relative to stable function compensation;
- decompensation.
At the first stage, the maximum activation of body processes occurs. At the same time, changes are observed at all levels: from cells to organ systems. But with the growth of the functional activity of the organ, its depletion and decay of elements occur. Therefore, the maximum mobilization of all reserve structures in the body is necessary.
At the stage of relatively stable compensation, a restructuring of the organ structure is observed. It changes in such a way as to be able to provide sustainable compensation for as long as possible. At the same time, the organ is saturated with vessels, the number of cells grows, as well as their size.
As a result of this, the body increases, which is called hypertrophy. An example would be the hypertrophic heart in athletes. The need to pump more blood to supply actively working muscles leads to an increase in the size of the heart muscle.
The last stage of compensatory-adaptive reactions - decompensation - has received such a name, as it is manifested by dysfunction. It occurs when the cause of compensation has not been eliminated in time. The reserve of the body is gradually depleted. The energy that is produced in it becomes insufficient for a hypertrophied organ. As a result, metabolism is gradually disrupted, the affected organ ceases to function, and other organs and systems begin to suffer after it.
Features of regeneration
Now it's time to analyze the features of certain types of compensatory-adaptive reactions. Hypertrophy is one of the most common varieties. It consists in the renewal of the structural elements of the tissue and organ. This is due to the growth of new elements in place of the damaged ones. There are three types of hypertrophy:
- physiological;
- pathological;
- reparative.
Physiological regeneration is a normal process in the human body. Cells are not immortal, each of them has a certain lifespan. For example, erythrocytes (red blood cells) live up to 120 days. In place of the dead, new cells are constantly formed, which are differentiated from stem cells in the bone marrow.
Reparative regeneration
The essence of reparative regeneration corresponds to that of physiological regeneration. But reparative is characteristic only for pathological processes. It is characterized by faster activation of adaptation mechanisms, mobilization of body reserves. That is, in essence, reparative regeneration is a faster and more powerful version of physiological.
There are two types of reparative regeneration: complete and incomplete. Full still received the name of restitution. She ischaracterized by the fact that the dead tissue is replaced by an absolutely identical structure. This is characteristic primarily of regeneration at the cellular level. Incomplete regeneration, or substitution, consists in replacing the dead structure with connective tissue. Clinically it looks like a scar.
Pathological regeneration, according to its name, is one of the variants of the pathology of compensatory-adaptive reactions. It occurs due to a violation of the mechanisms of regeneration. An example is the development of keloid scars, neuromas in trauma - excessive growths of damaged nerves, too large calluses in a fracture.
Features of hypertrophy
Another fairly common variant of the compensatory-adaptive reaction of the body in pathology and in the norm is hypertrophy. It consists in an increase in the size of a tissue or an entire organ due to an increase in the size of cells. There are several types of hypertrophy:
- working;
- vicar;
- hormonal;
- hypertrophic growths.
Working variety of hypertrophy occurs in both he althy people and in pathology. An example of physiological hypertrophy would be cardiac enlargement in athletes, which was mentioned earlier. Since this organ performs an increased function in sports people and people who do hard physical work, its cells gradually increase in size, which leads to a thickening of the myocardium (heart muscle).
Workingcardiac hypertrophy occurs in pathology, and the causes can be both intracranial (inside the heart) and extracranial (outside it). The first group includes inflammation of the heart wall, congenital and acquired heart valve defects. The function of the organ in these pathologies suffers. Therefore, in order to somehow provide the internal organs with the necessary amount of blood, hypertrophy develops.
A striking example of extracranial causes is arterial hypertension. This is a condition characterized by high blood pressure. high blood pressure creates resistance to the ejection of blood from the heart. The organ has to exert more effort to push it out, which causes hypertrophy.
Vicarious and hormonal hypertrophy
Vicarious type of hypertrophy develops when one of the paired organs is removed. For example, in a person who has had one lung removed, the remaining one gradually grows to a very large size. This is a necessary measure to provide the body with enough oxygen.
Hormonal hypertrophy can also be normal and pathological. Biologically active substances (hormones) take part in its development. One example is uterine hypertrophy during pregnancy. This happens under the influence of the hormone progesterone.
Pathological hypertrophy develops when the function of the endocrine glands is impaired. For example, with increased production of growth hormone by the pituitary gland, acromegaly develops. At the same time, acral (final)parts of the body increase in size. Most often, a disproportionately large arm or leg grows.
Features of hyperplasia
If hypertrophy is an increase in the size of an organ due to the growth of a single cell, then hyperplasia occurs due to an increase in the number of cells. The mechanism of development of a compensatory-adaptive reaction according to the type of hyperplasia is an increase in the frequency of cell divisions (mitoses). This leads to a progressive increase in their number.
There are three types of hyperplasia:
- reactive, or protective;
- hormonal;
- substitute.
The first type of hyperplasia develops in organs that take part in the body's immune response when foreign agents enter - the thymus, lymph nodes, spleen, bone marrow, and so on. For example, with hemolysis (destruction of erythrocytes) or chronic hypoxia in people who live high in the mountains, hyperplasia of the erythrocyte germ in the bone marrow is observed. As a result, they produce more red blood cells than other people.
Hormonal hyperplasia occurs under the influence of biologically active substances. For example, in women during pregnancy, breasts increase precisely according to this principle. Another example is endometrial hyperplasia (inner layer of the uterus) before menstruation.
Hyperplasia can be pathological. With hyperplasia of the endocrine glands, they begin to synthesize hormones too actively, which leads to the development of various diseases. For example, with hyperplasia of the adrenal glands, Itsenko-Cushing's disease occurs, and the thyroid gland causes thyrotoxic goiter.
Features of changes in the body during hypoxia
Hypoxia (decrease in oxygen concentration in tissues) is one of the most shock conditions for the body. The brain can function without oxygen for an average of 6 minutes, after which it dies. Therefore, during hypoxia, the body is immediately mobilized to provide the internal organs with the maximum possible amount of oxygen.
The main mechanism of the body's compensatory-adaptive reaction during hypoxia is the activation of the sympathetic-adrenal system. It is characterized by the release of adrenaline and noradrenaline from the adrenal glands into the bloodstream. This leads to the development of several processes:
- increased heart rate (tachycardia);
- Peripheral vasospasm;
- increased blood pressure.
Due to the spasm of peripheral vessels, the phenomenon of centralization of blood circulation occurs. Thanks to this compensatory-adaptive reaction during hypoxia, blood flows to the most important organs for life: the brain, heart and adrenal glands.
But compensation cannot take place for a long time. If the cause of hypoxia is not eliminated in time, the heart rate slows down and the pressure drops.
Compensation principles
Compensatory-adaptive reactions of the organism do not develop chaotically. As noted above, they are universal, regardless of the type.irritant. Therefore, scientists have identified a number of rules according to which the body adapts to these conditions.
| Rule | Short explanation |
| Presence of the original background | Features of the mechanisms of compensatory-adaptive reactions directly depend on the initial state of regulatory systems and the metabolism of a particular individual |
| Compensatory cell regeneration and tissue enlargement (hyperplasia) | The ability of tissue to recover and grow depends on the concentration and ratio of hormones that stimulate and biologically active substances that inhibit this process |
| Redundancies | The human body contains a much larger number of elements than is necessary for the implementation of a compensatory reaction |
| Duplications | In the human body there are many paired structures (kidneys, lungs, eyes, adrenal glands) and structures that perform identical functions (hepatocytes in the liver, neurons in the nervous system, etc.). Thus, the body "insures itself" |
| Function reservations | There are structures that are in "sleep mode" when the body is calm. But when exposed to extreme conditions, they are activated. For example, the blood depot is located in the liver. It comes out from there into the general bloodstream during blood loss |
| Operational frequency | At rest, the structures of the body periodically change theirwork to perform a specific function. For example, the alveoli in the lungs open when air enters (inhale) and close when it exits |
| Possibility of replacing one function with another | Violation of one function in the body can be replaced by another due to the implementation of compensatory mechanisms |
| Buffs | Due to special mechanisms in the body, the minimum efforts of its structures lead to the development of powerful compensation |
| Increase sensitivity | Structures that are deprived of innervation, that is, the receipt of impulses from nerve fibers, become more sensitive |
The main ones are presented in this table.
