The limbic system is more than a structure at the edge of the brain. Limbic system of the brain Structure of the limbic system of the brain

Limbic (edging) system is a group of brain structures connected to each other and responsible for emotions. Sometimes this functional system is also called the “emotional brain.”

Structure (composition) of the limbic system

1. Structures old cortex (archicortex)

These structures are also called visceral brain, or olfactory brain.

Almost all structures of the archipaleocortex, i.e. old and ancient cortex, have bilateral connections with the limbic region midbrain in the presence of a large number of collaterals to diencephalon: thalamus and hypothalamus. This allows the archipaleocortex to change its influence reticular formation brain stem on visceromotor and somatomotor functions, and also modulates the influence of the brainstem reticular formation on the functions of the archipaleocortex itself.

Hippocampus (cornuum + dentate gyrus)

Pear-shaped lobe.

Olfactory bulbs.

Olfactory tubercle.

2. Structures ancient cortex (paleocortex, paleocortex)

Cingulate gyrus.

Subcallosal gyrus.

Parahippocampal gyrus.

Presubiculum.

3. Subcortical structures

Anterior nuclei of the thalamus.

Central gray matter of the midbrain.

Functions of the limbic system

The limbic system ensures homeostasis, self-preservation and preservation of the species; it plays an important role in the formation of various affective-emotional and autonomic reactions, has a significant impact on conditioned reflex activity and is involved in the motivation of behavior (R. MacLean).

Excitatory pathways in the limbic system

A circular path of excitation along certain structures was discovered J. Papez and received the name " Peipets' emotional circle ".

Circular excitation path:hippocampus - fornix - mamillary body - anterior nucleus of the thalamus - cingulate cortex - presubiculum - hippocampus .

The limbic system also has bilateral commissural connections. between hippocampi different hemispheres, providing interhemispheric interaction between them. In humans, a certain independence in the activity of both hippocampi was also discovered.

The hippocampus responds with evoked potentials to stimulation of many parts of the brain: entorial, piriform, prepiriform cortex, subbiculum, amygdala, hypothalamus, thalamus, midbrain tegmentum, septum, fornix and others, and irritation of the hippocampus leads to the appearance of evoked potentials in these structures, which speaks of neural connections between them.

The hippocampus has projection zones of various sensor systems . In this case, multimodal projection zones in the hippocampus overlap, which is achieved by the convergence of afferent inputs of different modalities onto the same hippocampal neurons. Most hippocampal neurons are characterized by their responses as polysensory, although a certain number of monosensory neurons are also found.

), participating in the regulation of autonomic functions, i.e., the activity of the autonomic nervous system (See Autonomic nervous system), internal (visceral) organs and systems. The term has limited distribution. Used in neurophysiology as a synonym for the term limbic system.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

See what “Visceral brain” is in other dictionaries:

VISCERAL- (Latin visceralis, from vis esga viscera), belonging to, pertaining to the viscera, visceral [as opposed to “parietal” (see), wall]. So, the V. skull (cranium viscerale) is called its section, including the beginning ... ...

- (s. visceralis) S., in which internal organs are affected, for example. heart, brain and (or) spinal cord, lungs, liver, stomach, kidneys... Large medical dictionary

- (from the Latin limbus border) olfactory, or visceral, brain, a set of parts of the brain, united by anatomical (spatial relationship) and functional (physiological) characteristics. The main part of HP... ...

- (synonym: limbic complex, visceral brain, rhinencephalon, thymencephalon) a complex of structures of the midbrain, diencephalon and telencephalon involved in the organization of visceral, motivational and emotional reactions of the body. The main part... ... Medical encyclopedia

SCULL- (cranium), i.e. the skeleton of the head of vertebrates, is composed of two main sections: the axial skull and the visceral skeleton. The axial skull is a cartilaginous or bony box that encloses and protects the brain, hearing organ and organ... ... Great Medical Encyclopedia

SYPHILIS- SYPHILIS. Contents: I. History of syphilis......515 II. Epidemiology...................519 III. Social significance of syphilis......524 IV. Spirochaeta pallida ............., 527 V. Pathological anatomy...........533 VI.… … Great Medical Encyclopedia

- (cranium) skeleton of the head of vertebrates and humans. There are axial and visceral parts. The axial, or cerebral, part represents the anterior continuation of the axial skeleton of the body, growing around the brain, olfactory organs and... ... Great Soviet Encyclopedia

I a painful sensation reflecting the psychophysiological state of a person, which occurs under the influence of super-strong or destructive stimuli. The biological and physiological significance of pain is that it signals the presence... ... Medical encyclopedia

I Reflex (lat. reflexus turned back, reflected) is a reaction of the body that ensures the emergence, change or cessation of the functional activity of organs, tissues or the whole organism, carried out with the participation of the central nervous... ... Medical encyclopedia

- (cranium), the skeleton of the head of vertebrates, as well as the cartilaginous capsule that protects the brain in cephalopods. In vertebrates, it is formed by cartilage and/or bone. It is divided into the endocranium, represented by the embryonic cartilaginous skull and its... ... Biological encyclopedic dictionary

Hello, friends! Unfortunately, due to the heavy workload at the moment, it is not possible to publish articles more often than we would like. A drunk driver, whose criminal activity was legalized by the judges, again filed a lawsuit against me for 200 thousand rubles, and this is another waste of time, money and effort. I am glad that the Ministry of Eastern Development paid attention to my book “My Million Dollar Story” and gave a positive review of its publication. For now, let’s move on to the main topic of our conversation - deep limbic system of the brain. It was with putting the limbic system of the brain in order that my rehabilitation after a severe head injury began. Neurorehabilitation was the basis of the idea of the site and I think now is the time to start sharing my knowledge and life experience in this direction. However, first we must understand how our brain works and what aspects of life the deep limbic system is responsible for.

Limbic system- This is one of the most important parts of the brain, thanks to which a person lives his daily life. It is responsible for many key processes, from regulating emotions to processing information and storing memories. The main structures of the deep limbic system are amygdala, hippocampus, thalamus, hypothalamus, lumbar gyrus And basal ganglia. It is these parts that help a person to be active in society and establish social relationships. Emotions arise in the limbic system, after which, moving along neural pathways to the frontal cortex, they are interpreted and cause corresponding physical reactions. Therefore, any physical injury or disease of the limbic system is invariably accompanied by serious behavioral and emotional changes in a person. Likewise, it was very difficult for me to transfer myself from negative to positive, and even more difficult to “get” my motivation to perform actions that lead a person to success.

It should be noted that some modern researchers do not like the concept of the “limbic system”. They believe the theory is outdated and misleading because each component of the deep limbic system works individually and has a unique function. Therefore, in scientific research, it is best to focus on studying each component of the brain separately.

The hardest thing in the world is to think with your own head. This is probably why so few people do this.

Henry Ford

Neurophysiology of emotions

Everything originates in the brain and ends there. No matter how many theologians of the past and present wish it, it is the physical work of our brain that almost 100% determines the very course and quality of our life (the ability to feel a sense of satisfaction and happiness; to communicate with others; to be successful in one’s affairs, etc.) From work The brain also determines how a person will study at school, what kind of spouse he will become, whether he can be consistent in achieving his goals, how he will raise his children, and so on.

The brain is the organ of the mind. Modern anatomists describe the brain in terms of the evolutionary path along which we move. We have parts of the so-called ancient brain, the middle brain and the newborn brain, each of which has different properties. This model was developed and developed by the inventor of the term “limbic system,” the American physician and neuroscientist Dr. Paul D. MacLean. He identified three brain systems:

old reptilian brain;
midbrain (nucleus of the limbic system);
neocortex (newborn brain).

The operation of old “modules” remains unchanged for thousands of years. New structures grow from older brain modules, and are connected by the biological equivalent of wiring and digital interfaces. Their interaction still remains relatively unstable, so human behavior is never exactly the same and predictable. Bye limbic system is in a fragile balance - the person as a whole remains adequate, reasonable and striving for active daily activities. If the balance is disturbed, a “failure” occurs in the functioning of the biocomputer, which in essence is the human brain, resulting in significant changes in the mental and emotional sphere.

Children are not born with new brain programs. Old programs are already built into us and do not need to be learned. If we talk about examples, the most pronounced “old programs” include such negative qualities as greed (the desire to take possession of something you like in a predatory way), territorial aggression, anger and jealousy. Of course, there are also positive innate qualities, such as the desire to form new social units and altruistically help its members for the common good.

Simply put, the limbic system is the link that makes all the “modules” of the brain interact effectively, ensuring survival and interaction with society.

This, by the way, largely justifies women who entered the period of PMS. Now it is clear that their ability (from the point of view of many men) to become simply unbearable depends not only on their innate harmfulness and character traits, but also on chemical changes in the brain associated with hormonal changes in the body. Moreover, the deep limbic system of the brain contains the highest concentration of estrogen receptors, which is why they are more sensitive to changes associated with the menstrual cycle, childbirth or menopause. Their brains are physically unable to cope with such a strong release of hormones.

Deep Limbic System and Emotions

Many people are familiar with the state when everything around is viewed exclusively in a negative way. This condition haunted me for the first two years of my life. Negative emotions turn into a continuous veil of negativity and completely envelop a person. Only those lucky people whose limbic system is well developed and copes with its work have not experienced anything like this. Everyone else has it worse, since the limbic system includes three brain structures that can cause symptoms of depression and anxiety. This is the hypothalamus, amygdala o and hippocampus.

The deep limbic system governs our emotions

As for the general functions of the limbic system, in short, it is responsible for the following:

Sense of smell.

The amygdala directly intervenes in the process of olfactory sensation.

Appetite and culinary preferences.

The hypothalamus and amygdala work in this direction. The latter contributes to receiving emotional pleasure from eating, and the hypothalamus is responsible for a sense of proportion.

Sleep and dreams.

During dreams, the limbic system is one of the most active areas. This has been repeatedly proven by scientists from different countries using neuroimaging methods.

Emotional reactions.

The limbic system modulates emotional responses. This process involves the amygdala, hypothalamus, lumbar gyrus and basal ganglia.

Sexual behavior.

The limbic system is also involved in sexual behavior through the hypothalamus and various neurotransmitters, particularly dopamine.

Addiction and motivation.

This is why a thorough understanding of the functioning of the limbic system is so important to know when treating depression and drug addiction. After all, relapses of these problems are usually associated with the release of excitatory neurotransmitters in the responsible areas of the brain (hippocampus, amygdala).

Memory.

As we already know, emotional reactions are associated with the limbic system. But emotions are also involved in the search and consolidation of memory, so one of the functions of the limbic system is emotional memory.

Social cognition and interaction.

It refers to the thought processes involved in understanding and interacting with other people. Social cognition includes direct perception of others, basic communication skills, emotional processing, and working memory. Here the limbic system assists with the complex behaviors required for social interactions.

The influence of the limbic system on emotional coloring

In this case deep limbic system takes on the role of a prism through which people perceive everything that happens. Thanks to her work, any event takes on an emotional coloring (the emotions themselves depend on the emotional state of the person). When the activity of the limbic system increases and the system is in a state of flux for some time overexcited state, this leads to exhaustion and suppression of the work of all its structures. And then even the simplest and most harmless things will be perceived through negativity.

A simple example: a conversation between a conditionally normal person and a person with a hyperactive limbic system (already in a negative mood). In this case, the interlocutor will interpret almost everything said in a negative way. A person’s characteristic fears will be the fear that something is not being told to him or that he is being told a lie. The effect of “reading between the lines” is also possible (when irony or insult is heard in harmless speech patterns). If this situation continues long enough, it causes a reaction of rejection from society and a desire to retire from everything that causes pain.

Motivation and aspiration

Aspirations and motivation - These are also areas of operation of the deep limbic system. Everyone can feel her work in this direction by “turning on” in the morning and finding incentives to get out of a comfortable bed every day and do necessary and useful work throughout the day. The hypothalamus plays a key role here. As the structure responsible for sleep and appetite, it is 80% responsible for impaired motivation and many other emotional problems. Now you understand why you can’t become who you want until you put the deep limbic system of your brain in order. You won't get far with low motivation.

The limbic system controls human motivation

Communication and attachment formation

A person's ability to communicate and form attachments is a direct result of the deep limbic system. This fact has been repeatedly proven by experiments on animals. For example, experimental rats that had this part of the brain removed showed complete indifference to their relatives. Mothers no longer fed their babies, perceiving them as inanimate objects.In other experiments, normal and operated rats were placed in the center of a maze, in the center of which a lot of food was hidden. Healthy rats, having eaten, began to actively call their relatives so that they would take part in the meal. Rats with brain structures removed did nothing of the sort. They only ate, defecated and slept.

There is a statement that says that humans are just one type of social animal. And it's hard to deny. After all, regardless of the characteristics of personal worldview, without maintaining connections, a person cannot feel truly positive.

Smell

The limbic system and the sense of smell are connected in the most direct way. Of the five senses, only the olfactory system is connected directly to the brain's "computing center." Other sensory organs (hearing, vision, taste, touch) use an intermediate “crutch” that redistributes the received data to the necessary areas of the brain. It is with this interesting feature that such a strong influence of smells on a person’s emotional state is associated. And today this is actively used by marketers involved in the sales of deodorants and various perfumes. After all, a beautiful and fresh aroma evokes positivity and attracts, but an unpleasant odor, on the contrary.

Sexuality

The activity of the limbic system directly affects human sexuality. Mutual sexual attraction and arousal triggers a chain of neurochemical reactions in the brain, dulling critical and stimulating emotional perceptions of each other. Actually, because of this peculiarity of the limbic system, that very outburst of emotions occurs, which often ends in “casual sex” and its unplanned results. Why do women become more attached to their partners after such relationships? Scientists have an answer to this question too. This reaction is the result of the fact that the limbic system in women is larger than in men, and therefore the limbic attachment formed by it will also be stronger. In one way, this makes them stronger (higher empathy and easier personal connections), but the benefits come at the cost of increased sensitivity to hormonal changes and a tendency to depression. Forward

– the broadest totality, which represents a morphofunctional association of systems. They are found in different parts of the brain.

Let's look at the functions and structure of the limbic system in the diagram below.

System structure

The limbic system includes:

limbic and paralimbic formations
anterior and medial nuclei of the thalamus
medial and basal parts of the striatum
hypothalamus
oldest subcortical and mantle parts
cingulate gyrus
dentate gyrus
hippocampus (seahorse)
septum (septum)
amygdala.

The diencephalon contains 4 main structures of the limbic system:

habenular nuclei (lead nuclei)
thalamus
hypothalamus
mastoid bodies.

main functions of the limbic system

Connecting with Emotions

The limbic system is responsible for the following activities:

sensual
motivational
vegetative
endocrine

You can also add instincts here:

food
sexual
defensive

The limbic system is responsible for regulating the wakefulness-sleep process. It develops biological motivations. They predetermine complex chains of effort. These efforts lead to the satisfaction of the above vital needs. Physiologists define them as the most complex unconditioned reflexes or instinctive behavior. For clarity, we can recall the behavior of a newborn baby when breastfeeding. This is a system of coordinated processes. As the child grows and develops, his instincts are increasingly influenced by consciousness, which develops as he learns and is raised.

Interaction with the neocortex

The limbic system and neocortex are tightly and inextricably interconnected with each other and the autonomic nervous system. On this basis, it connects two of the most important activities of the brain - memory and feelings. Typically, the limbic system and emotions are linked together.

Deprivation of part of the system leads to psychological inertia. The urge leads to psychological hyperactivity. Increased activity of the amygdala activates methods for provoking anger. These methods are regulated by the hippocampus. The system triggers eating behavior and awakens a sense of danger. These behaviors are regulated by both the limbic system and hormones. Hormones are in turn produced by the hypothalamus. This combination significantly influences life through the regulation of the functioning of the autonomic nervous system. Its significance is called the visceral brain. Determines the sensory-hormonal activity of the animal. Such activity is practically not subject to brain regulation either in animals, or even less so in humans. This demonstrates the relationship between emotions and the limbic system.

System functions

The main function of the limbic system is to coordinate actions with memory and its mechanisms. Short-term memory is usually combined with the hippocampus. Long-term memory is with the neocortex. The manifestation of personal skills and knowledge from the neocortex occurs through the limbic system. For this purpose, sensory-hormonal stimulation of the brain is used. This provocation brings up all the information from the neocortex.

The limbic system also performs the following significant function - verbal memory of incidents and experiences gained, skills, and knowledge. All this looks like a complex of effector structures.

In the works of specialists, the system and functions of the limbic system are depicted as an “anatomical emotional ring.” All aggregates connect with each other and other parts of the brain. The connections with the hypothalamus are especially multifaceted.

It defines:

human sensual mood
his motivation for action
behavior
processes of acquiring knowledge and remembering.

Violations and their consequences

If the limbic system is disturbed or there is a defect in these complexes, amnesia progresses in patients. However, it should not be defined as a place where certain information is stored. It connects all the separate parts of memory into generalized skills and incidents that are easy to reproduce. Disruption of the limbic system does not destroy individual fragments of memories. These damages destroy their conscious repetition. In this case, various pieces of information are stored and serve as a guarantee for procedural memory. Patients with Korsakoff's syndrome can learn some other new knowledge. However, they will not know how and what exactly they learned.

Defects in its activities result from:

brain injury
neuroinfections and intoxications
vascular pathologies
endogenous psychoses and neuroses.

It all depends on how significant the defeat was, as well as the restrictions. Quite real:

epileptic convulsive states
automatisms
changes in consciousness and mood
derealization and depersonalization
auditory hallucinations
taste hallucinations
olfactory hallucinations.

It is no coincidence that when the hippocampus is predominantly damaged by alcohol, a person’s memory for recent incidents suffers. Patients undergoing treatment for alcoholism in the hospital suffer from the following: they do not remember what they ate for lunch today, whether they had lunch at all or not, or when they last took medications. At the same time, they perfectly remember events that took place in their lives long ago.

It has already been scientifically substantiated - the limbic system (more precisely, the amygdala and the transparent septum) is responsible for processing certain information. This information was received from the olfactory organs. At first, the following was stated: this system is capable of exclusively olfactory function. But over time it became clear: it is also well developed in animals without the sense of smell. Everyone knows about the importance of biogenic amines for leading a full life and activity:

dopamine
norepinephrine
serotonin.

The limbic system has them in huge quantities. The manifestation of nervous and mental illnesses is associated with the destruction of their balance.

The structure and functions of the limbic system have not yet been studied in many ways. Conducting new research in this area will make it possible to determine its current place among other parts of the brain and will allow our practitioners to treat diseases of the central nervous system with new methods.

2. Self-regulation of autonomic functions

3. The role of the limbic system in the formation of motivations, emotions, memory organization

Conclusion

References

Introduction

There are six lobes in each of the two hemispheres of the brain: the frontal lobe, the parietal lobe, the temporal lobe, the occipital lobe, the central (or insular) lobe, and the limbic lobe. A set of formations located predominantly on the inferomedial surfaces of the cerebral hemispheres, closely interconnected with the hypothalamus and overlying structures, was first designated as an independent formation (limbic lobe) in 1878 by the French anatomist Paul Broca (1824-1880). Then only the marginal zones of the cortex, located in the form of a bilateral ring on the inner border of the neocortex (Latin: limbus - edge), were classified as the limbic lobe. These are the cingulate and hippocampal gyri, as well as other areas of the cortex located next to the fibers coming from the olfactory bulb. These zones separated the cerebral cortex from the brain stem and hypothalamus.

At first it was believed that the limbic lobe performed only the function of smell and therefore it was also called the olfactory brain. Subsequently, it was found that the limbic lobe, together with a number of other neighboring brain structures, perform many other functions. These include coordination (organization of interaction) of many mental (for example, motivations, emotions) and physical functions, coordination of visceral systems and motor systems. In this regard, this set of formations was designated by the physiological term - limbic system.

1. The concept and significance of the limbic system in nervous regulation

The occurrence of emotions is associated with the activity of the limbic system, which includes some subcortical formations and areas of the cortex. The cortical sections of the limbic system, representing its highest section, are located on the lower and inner surfaces of the cerebral hemispheres (cingulate gyrus, hippocampus, etc.). The subcortical structures of the limbic system include the hypothalamus, some nuclei of the thalamus, midbrain and reticular formation. Between all these formations there are close direct and feedback connections that form the “limbic ring”.

The limbic system is involved in a wide variety of activities of the body. It forms positive and negative emotions with all their motor, autonomic and endocrine components (changes in breathing, heart rate, blood pressure, activity of the endocrine glands, skeletal and facial muscles, etc.). The emotional coloring of mental processes and changes in motor activity depend on it. It creates motivation for behavior (a certain predisposition). The emergence of emotions has an “evaluative influence” on the activity of specific systems, since, by reinforcing certain methods of action, ways of solving assigned tasks, they ensure the selective nature of behavior in situations with many choices.

The limbic system is involved in the formation of indicative and conditioned reflexes. Thanks to the centers of the limbic system, defensive and food conditioned reflexes can be produced even without the participation of other parts of the cortex. With lesions of this system, strengthening of conditioned reflexes becomes difficult, memory processes are disrupted, selectivity of reactions is lost and their excessive strengthening is noted (excessively increased motor activity, etc.). It is known that the so-called psychotropic substances that change the normal mental activity of a person act specifically on the structures of the limbic system.

Electrical stimulation of various parts of the limbic system through implanted electrodes (in experiments on animals and in the clinic during the treatment of patients) revealed the presence of pleasure centers that form positive emotions, and centers of displeasure that form negative emotions. Isolated irritation of such points in the deep structures of the human brain caused the appearance of feelings of “causeless joy,” “pointless melancholy,” and “unaccountable fear.”

In special experiments with self-irritation on rats, the animal was taught to close a circuit by pressing its paw on a pedal and produce electrical stimulation of its own brain through implanted electrodes. When the electrodes are localized in the centers of negative emotions (some areas of the thalamus), the animal tries to avoid closing the circuit, and when they are located in the centers of positive emotions (hypothalamus, midbrain), the paw presses the pedal almost continuously, reaching up to 8 thousand irritations in 1 hour.

The role of emotional reactions in sports is great (positive emotions when performing physical exercises - “muscular joy”, the joy of victory and negative ones - dissatisfaction with the sports result, etc.). Positive emotions can significantly increase, and negative emotions can significantly decrease, a person’s performance. The great stress that accompanies sports activity, especially during competitions, also creates emotional stress - the so-called emotional stress. The success of an athlete’s motor activity depends on the nature of the reactions of emotional stress in the body.

The regulation of the activity of internal organs is carried out by the nervous system through its special department - the autonomic nervous system.

All functions of the body can be divided into somatic, or animal (from the Latin animal - animal), associated with the activity of skeletal muscles, - organization of posture and movement in space, and vegetative (from the Latin vegetativus - plant), associated with the activity of internal organs, -processes of respiration, blood circulation, digestion, excretion, metabolism, growth and reproduction. This division is arbitrary, since vegetative processes are also inherent in the motor system (for example, metabolism, etc.); motor activity is inextricably linked with changes in breathing, blood circulation, etc.

Stimulation of various body receptors and reflex responses of nerve centers can cause changes in both somatic and autonomic functions, i.e., the afferent and central sections of these reflex arcs are common. Only their efferent sections are different.

The totality of efferent nerve cells of the spinal cord and brain, as well as cells of special nodes (ganglia) innervating internal organs, is called the autonomic nervous system. Consequently, this system is the efferent part of the nervous system, through which the central nervous system controls the activities of the internal organs.

A characteristic feature of the efferent pathways included in the reflex arcs of autonomic reflexes is their two-neuron structure. From the body of the first efferent neuron, which is located in the central nervous system (in the spinal, medulla oblongata or midbrain), a long axon extends, forming a prenodal (or preganglionic) fiber. In the autonomic ganglia - clusters of cell bodies outside the central nervous system - excitation switches to the second efferent neuron, from which a postnodal (or postganglionic) fiber departs to the innervated organ.

The autonomic nervous system is divided into 2 sections - sympathetic and parasympathetic. The efferent pathways of the sympathetic nervous system begin in the thoracic and lumbar parts of the spinal cord from the neurons of its lateral horns. The transfer of excitation from the prenodal sympathetic fibers to the postnodal ones occurs in the ganglia of the border sympathetic trunks with the participation of the mediator acetylcholine, and the transfer of excitation from the postnodal fibers to the innervated organs - with the participation of the mediator adrenaline, or sympathin. The efferent pathways of the parasympathetic nervous system begin in the brain from some nuclei of the midbrain and medulla oblongata and from neurons of the sacral spinal cord. Parasympathetic ganglia are located in close proximity to or within the innervated organs. The conduction of excitation at the synapses of the parasympathetic pathway occurs with the participation of the mediator acetylcholine.

The autonomic nervous system, by regulating the activity of internal organs, increasing the metabolism of skeletal muscles, improving their blood supply, increasing the functional state of nerve centers, etc., contributes to the implementation of the functions of the somatic and nervous system, which ensures the active adaptive activity of the body in the external environment (reception of external signals, their processing, motor activity aimed at protecting the body, searching for food, in humans - motor acts associated with household, work, sports activities, etc.). The transmission of nervous influences in the somatic nervous system occurs at high speed (thick somatic fibers have high excitability and a conduction speed of 50-140 m/sec). Somatic effects on individual parts of the motor system are characterized by high selectivity. The autonomic nervous system is involved in these adaptive reactions of the body, especially under extreme stress (stress).

Another significant aspect of the activity of the autonomic nervous system is its huge role in maintaining the constancy of the internal environment of the body.

The constancy of physiological parameters can be ensured in various ways. For example, the constancy of blood pressure is maintained by changes in the activity of the heart, pro. light of blood vessels, the amount of circulating blood, its redistribution in the body, etc. In homeostatic reactions, along with nervous influences transmitted along vegetative fibers, humoral influences are important. All these influences, unlike somatic ones, are transmitted in the body much more slowly and more diffusely. Thin autonomic nerve fibers are characterized by low excitability and low speed of excitation conduction (in prenodal fibers the conduction speed is 3-20 m/sec, and in postnodal fibers it is 0.5-3 m/sec).