The activity of the cerebellum is regulated. The cerebellum, its structure and functions. - Panov's test is used in clinical practice to determine the presence of mild static ataxia

The cerebellum is involved in almost all movements, it helps a person to throw a ball or walk around the room. Cerebellar problems are rare and are mainly associated with impaired movement and coordination.

Anatomy of the brain

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The brain consists of four lobes, each lobe has its own function.

The frontal lobe is located in the front and top of the brain. It is responsible for high levels of human thinking and behavior such as planning, judgment, decision making, control, and attention.

The parietal lobe is located at the top of the brain, behind the frontal lobe. It is responsible for receiving sensory information. The parietal lobe of the brain is responsible for understanding someone's position in their environment.

The temporal lobe is located in the lower anterior part of the brain. It is associated with visual memory, language and emotions.

And finally, the occipital lobe is located at the back of the brain and processes what a person sees.

Along with the lobes, the brain includes the cerebellum and the brain stem.

The brain stem controls vital functions such as breathing, circulation, sleep, digestion, and swallowing. These involuntary functions are under the control of the autonomic nervous system. The brain stem also controls reflexes.

The cerebellum is located in the lower back of the brain, behind the brainstem.

Cerebellar functions:

Movement coordination. Most body movements require the coordination of several muscle groups. The cerebellum allows the body to move smoothly.

Maintaining a balance. The cerebellum detects changes in the balance of movement. It sends signals to the body to adjust to movement.

Eye movement coordination.

The cerebellum helps the body learn movements that require practice and fine tuning. For example, the cerebellum plays a role in learning the movements required to ride a bicycle.

Researchers believe that the cerebellum influences thinking and is associated with language and mood, but these functions are not well understood.

Symptoms of damage to the cerebellum

The most common sign of a cerebellar disorder is impaired muscle control. This is because the cerebellum is responsible for controlling balance and voluntary movements.

Symptoms and signs of a cerebellar disorder include:

Lack of muscle control and coordination;

Difficulty walking;

Difficulties with speech;

Pathological eye movements;

Headache.

Cerebellar ataxia

Change in gait in a woman with cerebellar disease

ICD-10:

G11.1 Early cerebellar ataxia

G11.2 Late cerebellar ataxia

G11.3 Cerebellar ataxia with impaired DNA repair

Ataxia is a disorder of the cerebellum.Ataxiais a loss of muscle coordination and control due to a problem with the cerebellum. It can be caused by a virus or a brain tumor. Loss of coordination is often the initial sign of ataxia. Other symptoms include blurry vision, difficulty swallowing, fatigue, difficulty with precise muscle control, and changes in mood and thinking.

There are several diseases that cause symptoms of ataxia. These are heredity, poisons, stroke, tumors, head injuries, multiple sclerosis, cerebral palsy, viral infections.

Genetic or hereditary ataxia is caused by a genetic mutation. There are several different mutations and types of hereditary ataxia. These disorders are rare, the most common type being Friedreich's ataxia, which affects up to 1 in 50,000 people. Symptoms of Friedreich's ataxia usually appear already in childhood.

Idiopathic (sporadic) ataxia is a group of degenerative movement disorders with no evidence of inheritance. Impaired coordination and speech are the first symptoms. Idiopathic ataxia usually progresses slowly and may be accompanied by syncope, abnormal heart contractions, erectile dysfunction, and loss of bladder control.

So far, there is no specific treatment to alleviate or eliminate the symptoms of the disease, except in cases of ataxia, where the cause is a lack of vitamin E.

There is ataxia caused by toxins. Poisons damage the nerve cells of the brain - the cerebellum, which leads to ataxia.

Toxins that cause cerebellar ataxia:

Alcohol;

Medications, especially barbiturates and benzodiazepines;

Heavy metals such as mercury and lead;

Paint solvents.

Treatment and recovery depends on the toxin that caused the brain damage.

Viral ataxia. This disorder is called acute cerebellar ataxia and most often affects children. Ataxia is a rare complication of chickenpox.

Acute cerebellar ataxia can also be caused by Coxsackie virus, Epstein-Barr virus and HIV. Lyme disease, caused by bacteria, is also associated with these conditions.

Ataxia usually disappears a few months after the disappearance of the viral infection.

Strokecan affect any area of ​​the brain. The cerebellum is a less common site for stroke. A blood clot or hemorrhage in the cerebellum can cause ataxia, resulting in headache, dizziness, nausea, and vomiting. Stroke treatment can reduce the symptoms of ataxia.

brain tumorsare benign when they do not spread throughout the body, and malignant when tumors metastasize.

Symptoms of a tumor in the cerebellum include:

Headache;

Vomiting without nausea;

Difficulty walking;

Diagnosis and treatment will vary depending on age, health status, course of the disease, and other factors.

To avoid damage to the cerebellum, the overall health of the brain must be maintained. Reducing the risk of stroke, brain injury, and exposure to poisons can help prevent some forms of ataxia.

Used Books:

1. De Smet, Hyo Jung, et al. " The cerebellum: its role in language and related cognitive and affective functions» Brain and language 127.3 (2013): 334-342.
2. Lippard, Jim. " The Skeptics Society & Skeptic magazine.»

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Man is a spatially oriented, complex kinetic system. To perform any activity, the human body makes many precise, coordinated movements, while maintaining a certain posture and balance, for which the cerebellum is responsible.

It is one of the most ancient structures of the brain and occupies about ten percent of its total mass, having at its disposal, however, half of the neurons. The cerebellum is located in the posterior cranial fossa behind the brainstem and pons and belongs to the central nervous system. Its mass in an adult is approximately 120 - 160 grams, and the size in cross section reaches 10 centimeters. It is worth noting the proximity of the cerebellum to the visual and auditory areas.

The cerebellum is called a small brain, which is determined by a similar structure. Like the brain, it consists of two hemispheres connected by a worm, and also has lobes, a cortex and a kind of convolutions - furrows.

The cerebellum is divided into three lobes:

1. Vestibulocerebellum
   The most ancient part of the cerebellum is associated with the vestibular and reticular nuclei of the brainstem. Responsible for the balance of the body in space and controls the tone of the muscles that connect the head to the spine, and the muscles located along the spine (axial). If the vestibulocerebellum is damaged, patients have a violation of gait, coordination of eye movements and contraction of the axial muscles.
2. spinocerebellum
   Responsible for the transmission of nerve impulses along the spinal cerebellar pathways, thereby taking part in the regulation of muscle tone of the limbs and spine. If the spinocerebellum is damaged, patients have a violation of the coordinated movements of the limbs.
3. Cerebrocerebellum
   The youngest structure of the cerebellum, but at the same time the largest and most complex. Responsible for communication with the cerebral cortex. It receives nerve impulses from oppositely located motor areas of the cerebral cortex and is involved in the coordination of precise, fine motor skills of the limbs, conscious movements.

The internal structure of the cerebellum is represented by white matter (cerebral body) and gray matter (cerebellar nuclei and cortex).

There are three layers of the cerebellar cortex and five types of cells in them:

1. The outer, or molecular, layer includes basket and stellate neurons.
2. The middle or ganglionic layer is represented by Purkinje cells (pear-shaped), which are responsible for the main functions of the cerebellum, providing communication with the deep nuclei of the cerebellum through their axons. If you pay attention to the pattern of the dendrites of these cells on the cut, you can see that it resembles the structure of tree branches, since the fibers of Purkinje cells are arranged in parallel and, as it were, two-dimensionally.
3. In the inner layer are granule cells and Golgi cells, with their dendrites rising into the molecular layer.

Cerebellar nuclei

serrated nucleus

It receives signals from the cortex of the cerebellar hemispheres and is responsible for the regulation of voluntary movements, that is, controlled by human consciousness. The dentate nucleus also includes pathways responsible for skeletal muscle motor function and visuo-spatial orientation.

Insertion cores

These include corky and spherical nuclei. They receive signals from the bark of the worm. Provides the work of the muscles of the neck and torso.

tent core

It is the most ancient nucleus and is associated with the vestibular apparatus, therefore, when it is damaged, an imbalance in the body develops.

Cerebellar peduncles

All information to and from the nuclei is transmitted using legs:

The lower pair includes sensory fibers from the medulla oblongata and descending fibers from the vestibular nuclei.

The middle pair contains sensitive fibers of the nuclei of the bridge, controls the activity of the cortex of the cerebral hemispheres.

The upper pair consists of descending fibers of the cerebellar nuclei and sensory fibers from the spinal cord.

Conducting paths

The pathways of the cerebellum, formed by means of short and long processes of neurons, can go both from the cerebellar cortex to its nuclei (the so-called afferent, or sensitive), and from the nuclei to other brain structures (efferent, or motor).

Afferent pathways

Conducting afferent pathways include two types of fibers - mossy and liana-shaped. The former form tracts with their own nuclei of the bridge and have connections with granule cells of the inner layer of the cerebellar cortex. The latter are associated with Purkinje cells in the middle layer of the cortex and form tracts with the vestibular nuclei, the spinal cord, the reticular formation, and the medulla oblongata.

Efferent Pathways

They are divided into intracerebellar and extracerebellar. The first go to the subcortical nuclei of the cerebellum as axons of Purkinje cells. The latter come out as part of the cerebellar peduncles and are pumped by the stem and thalamic nuclei. In addition, connections with the parietal and temporal regions of the brain are formed through efferent pathways.

Functions of the cerebellum

The cerebellum performs the following main functions: coordination of fast and slow movements, maintenance of skeletal muscle tone; maintaining balance, body position in space and regulation of autonomic functions.

You can detail the functions of the cerebellum using the example of the features of its structure:

• The worm is responsible for the coordinated work of the eyes, body and head during movement, processing signals from Purkinje cells and planning the speed and amplitude of upcoming movements.
• If we talk about the gray matter of the cerebellum, then its functions are mainly implemented by the Purkinje cells located in the middle layer. Their task is to collect information, process it and transfer it to the inner layer and other parts of the brain. These cells subtly react to the type, direction and speed of movement, receiving information from the retina, eye muscles, vestibular analyzer and skeletal muscle receptors.
• The inner layer is connected to such formations as the thalamus, pons, medulla oblongata and cranial nuclei through the legs. The upper pair of legs is a transmitter of information to the frontal lobe, where the centers of behavior and thinking are located.
• The outer layer performs a braking function for the middle and inner.
• In addition, the small brain is involved in the control of vital organ systems within the autonomic nervous system. Due to the work of the cerebellum, blood pressure rises, the motor and excretory function of the gastrointestinal tract is regulated.
• Since the 1990s, it has been believed that the functions of the cerebellum also include participation in the formation of cognitive abilities. Continuous analysis of sensory and motor information, probabilistic evaluation, associative thinking, memory, speech, and even the formation of attachments and emotions are also carried out by the cerebellum.

Pathologies

Ataxia

The scientific term "ataxia" describes a violation of the vestibular apparatus and includes static, stato-locomotor and kinetic types of ataxia. A characteristic symptom of stato-locomotor ataxia is the "drunken" gait of the patient. With static ataxia, a person does not feel support under his feet, he tries to spread his legs wide and spread his arms in order to maintain balance in a certain position. When performing a test in the Romberg position (standing in a pose with legs together), the patient will fall to the side. With kinetic ataxia, there is a violation of precise movements, which is manifested by trembling of the hands when trying to point to an object.

Dystonia

This term describes a violation of the tone of the muscles of the flexors and extensors, due to which hypertonicity develops in some muscles, and, on the contrary, atony in others. As a result, more energy is spent on the implementation of certain motor programs and asthenia develops - muscle fatigue and a decrease in their strength.

dysarthria

When the cerebellum is damaged, the speech of patients is disturbed. It becomes slow, indistinct and inarticulate, or, on the contrary, chanted, fragmentary, with a clear violation of sound coloring, which is associated with a loss of coordination of the muscles involved in voice reproduction.

Adiadochokinesis

Damage to the cerebellum leads to the impossibility of analyzing and processing information about the speed, amplitude and strength of movements. As a result, the patient loses the ability to smoothly perform movements with different limbs, especially when changing the type of movements. To check this symptom, the doctor asks the patient to quickly turn his arms outstretched in front of him. Normally, movements should be smooth and symmetrical; with cerebellar pathology, one of the hands will lag behind.

Dysmetria

This is the name of the impossibility of performing precise actions, missing during pointing samples due to impaired coordination between antagonist muscles.

Intention tremor

An important distinguishing feature of trembling in cerebellar lesions is that it intensifies at the final stage of movement, that is, when approaching an object. This is due to the connection of the cerebellum with the sensory apparatus with the constant processing of visual information about the position of objects.

nystagmus

This term describes the occurrence of involuntary rhythmic movements of the eyeballs, since normally the cerebellum regulates the combined movement of the eyes, head and trunk.

Among other things, the symptoms of cerebellar disorders include dizziness, nausea, vomiting, impaired handwriting, visual-spatial orientation and attention.

The cerebellum has a very complex structure and functions that go beyond the control of balance and movement attributed to it.

The cerebellum is located in the posterior cranial fossa. It is separated from the rest of the brain by a hard shell - cerebellar plaque. Together with the pons, the cerebellum forms the hindbrain. Anterior to the cerebellum are the pons and the medulla oblongata.

In mammals, the cerebellum consists of two hemispheres and an unpaired section - the worm. The cerebellum is connected to the brain stem by three pairs of peduncles.:

• Thick middle legs, as it were, cover the medulla oblongata and, expanding, pass into the pons.
• The superior peduncles originate in the dentate nuclei of the cerebellum and travel to the quadrigemina of the midbrain.
• The third pair of legs (lower) goes down, merging with the medulla oblongata.

Afferent fibers entering the cerebellum are predominantly part of the middle and lower peduncles, while efferent fibers are collected mainly in the upper cerebellar peduncles.

The entire surface of the cerebellum is divided by deep grooves into shares. In turn, each lobe is divided by parallel grooves into convolutions; groups of convolutions form slices cerebellum.

The cerebellum is divided into three phylogenetic divisions:

• most isolated flocculonodular lobe(X) is ancient cerebellum (archicerebellum). The flocculonodular lobe consists of a tuft, a nodule, and the lower part of the worm. Here the projections from the vestibular nuclei of the medulla oblongata end.
• The next section of the cerebellum is old cerebellum, or paleocerebellum, - includes sections of the worm corresponding to the anterior lobe, pyramids, uvula and parafloccular section. In the paleocerebellum there are projections of the ascending spinal cerebellar tracts that carry information from muscle receptors.
• Third department - new cerebellum, or neocerebellum, - consists of the hemispheres and sections of the worm that appear in mammals, which are located caudal to the first furrow. The neocerebellum receives afferent impulses from vast areas of the cerebral cortex (frontal, parietal, temporal and occipital lobes) through tracts switching in the nuclei of the pons varolii.

hemispheres and cerebellar vermis consist of the gray matter lying on the periphery - the cortex - and the white matter located deeper, in which clusters of nerve cells are laid that form the nuclei of the cerebellum. Bark The cerebellum is represented by three layers, each of which has a specific set of cellular elements. Layers of the cerebellar cortex:

1. The most superficial layer molecular- consists of parallel fibers - axons of granule cells, and branchings of dendrites of Purkinje cells. Purkinje cells have a flattened dendrite oriented parallel to the sagittal zones of the lobules (folia) of the cerebellum. Parallel fibers are oriented strictly transversely (perpendicular) with respect to the follium and the sagittal direction of the mossy fibers. In the lower part of the molecular layer, the bodies of basket cells are located, the axons of which braid the bodies and initial segments of the axons of Purkinje cells. Here, in the molecular layer, there is a certain amount of stellate cells.
2. Below the molecular layer is ganglionic the layer in which the bodies of Purkinje cells are concentrated. These large cells are oriented vertically with respect to the surface of the cerebellar cortex. Their dendrites rise up and branch widely in the molecular layer. The dendrites of Purkinje cells contain many spines on which parallel fibers of the molecular layer form synapses. Axons of Purkinje cells descend to the nuclei of the cerebellum. Part of them ends on the vestibular nuclei. In practice, the axons of Purkinje cells are the only exit from the cerebellar cortex.
3. Beneath the ganglion layer lies the granular layer, which contains a large number of granule cell bodies, or granule cells. The axons of the granule cells rise vertically upwards into the molecular layer and branch there in a T-shape, forming parallel fibers. The plane of their branching is perpendicular to the plane of branching of the dendrites of Purkinje cells. Here, in the granular layer, there are Golgi cells, the axons of which approach the granule cells.

AT white matter The cerebellum contains three pairs of nuclei that form the main efferent outputs from the cerebellum:

1. tent core. The neurons of this nucleus send their processes to the vestibular nucleus of Deiters and to the reticular formation of the medulla oblongata and the pons, where the reticulospinal tract of the spinal cord originates. Thus, muscle tone is regulated.
2. intercalary, or intermediate, core, in humans is divided into spherical and corky nucleus. From the intercalated nucleus, axons go to the midbrain to the red nucleus. From here begins the rubrospinal tract, stimulating the tone of the flexor muscles through the motor centers.
3. serrated nucleus cerebellum, from which powerful bundles of fibers are sent to the ventrolateral nucleus of the thalamus, and then the axons of second-order neurons are projected into the motor cortex.

Axons of Purkinje cells approach the neurons of the cerebellar nuclei. It has been established that Purkinje cells of the worm establish direct connections with the nucleus of Deiters. This allows sometimes to refer Deiters' nucleus to the intracerebellar nuclei according to the functional principle.

Functions of the cerebellum

The cerebellum, as a suprasegmental organ that is part of the movement regulation system, performs the following important features:

1) regulation of posture and muscle tone. The medial vermiform zone of the cerebellum is most associated with the implementation of this function. This zone of the cerebellar cortex, as well as the flocculonodular lobe of the archicerebellum, receives afferent information signaling the posture and state of the locomotor apparatus. After processing this information from the cerebellar cortex through the nucleus of the tent, corrective commands are sent to the vestibular nucleus of Deiters, to the reticular formation of the trunk, and from there to the spinal centers along the reticulospinal and vestibulospinal tracts.

2) sensorimotor coordination of postural and purposeful movements . The intermediate zone of the cerebellar cortex receives information from the motor area of ​​the cerebral cortex. This information enters through the collaterals of the corticospinal tract and signals the impending purposeful movement. Comparison of the information coming through these two pathways allows the intermediate zone of the cerebellum to participate in coordination of purposeful movements with postural reflexes, in choosing the most optimal posture for performing the movement. Descending commands from the intermediate zone of the cerebellar cortex through the intercalated nucleus go to the red nucleus and further along the rubrospinal tract to the motor centers of the spinal cord.

3) coordination of fast purposeful movements, carried out on command from the cortex, cerebral hemispheres. As noted above, the lateral, phylogenetically youngest, cortex of the cerebellar hemispheres provides efferent projections to the dentate nucleus. This lateral area receives afferent input from various associative areas of the cerebral cortex. Through these afferent pathways, information about the intention of the movement enters the cortex of the cerebellar hemispheres. In the hemispheres and the dentate nucleus of the cerebellum, this information is converted into a movement program, which enters the motor areas of the cerebral cortex. In the future, the motor act is realized due to descending commands coming from the motor cortex to the spinal cord along the corticospinal tract. In addition, direct descending influences to the spinal centers can spread from the dentate nucleus of the cerebellum through the red nucleus.

This complex system of regulation of movements with the presence of feedback between the cerebellum and the cerebral cortex allows the cerebellar hemispheres to participate in organization of fast purposeful movements, flowing without taking into account the information coming from the ascending sensory pathways of the spinal cord. Such movements can occur in sports practice, when playing musical instruments and in some other activities.

4) control of visceral functions . Irritation of the cerebellum causes a number of vegetative reflexes, such as dilated pupils, increased blood pressure, etc. Removal of the cerebellum is accompanied by disturbances in cardiovascular activity, respiration, motility and the secretory function of the gastrointestinal tract. Electrophysiological methods revealed visceral projections of internal organs in the cerebellum. So, for example, when stimulating interoreceptors in the cerebellar cortex, evoked potentials are recorded. However, the regulation of visceral functions by the cerebellum is also aimed primarily at providing motor function.

With partial and general damage to the cerebellum, three symptoms are observed: atony, asthenia and astasia (Experiments of L. Luciani).

Atony characterized by a weakening of muscle tone, the inability to maintain a certain posture. Usually atony is accompanied by a symptom asthenia which is characterized by weakness and rapid muscle fatigue. The third symptom described by L. Luciani is astasia- manifests itself in the ability of muscles to give oscillatory and trembling movements. Muscle tremor is especially pronounced at the beginning and end of the movement, which greatly hinders the completion of a purposeful movement. This symptom is caused by a violation of sensorimotor coordination of postural and purposeful movements.

Removal of the cerebellum adversely affects the performance of voluntary movements. At the same time, friendly movements suffer the most - symptoms of asynergy. As a result of asynergy, the program of movement seems to disintegrate, and an integral movement does not consist of simultaneous friendly acts, but of a sequence of a number of simple movements. Asynergy is combined with dysmetria, or loss of proportionality and accuracy of movement. In cerebellar patients, the gait is deformed - ataxia. Ataxic gait is characterized by widely spaced legs and excessive movements, due to which the patient “throws” like a drunk

In mammals that have suffered an injury to the cerebellum, over time, quite effective compensation of its functions occurs. In all likelihood, this compensation is due to the function of the cerebral cortex, which has bilateral connections with the cerebellum. This fact testifies to the high plasticity of the cerebral systems of movement regulation.

The part of the brain responsible for coordinating movements, maintaining body balance and regulating muscle tone. In a newborn, the mass of the cerebellum is approximately 20 g, or 5.4% of the total body weight. By 5 months of life, it increases by 3 times, and by 9 months - by 4 times. Intensive growth of the cerebellum in the first year of life is determined by the formation during this period of differentiation and coordination of movements. In the future, its growth rate is reduced. By about 15 years of age, the cerebellum reaches the size of an adult.

The structure of the cerebellum

It is located behind the medulla oblongata and is placed under the occipital lobes of the cerebral hemispheres, in the cranial fossa. It distinguishes the lateral parts, or hemispheres, and the worm located between them. Unlike the spinal cord and brainstem, the gray matter (cortex) is located on the surface of the cerebellum, while the white matter is inside.

Gray matter consists of cells arranged in three layers:

• outer layer - consists of stellate and basket cells;
• middle layer - represented by large ganglion cells;
• inner granular layer - consists of granular cells, between which there are large stellate.

In the thickness of the cerebellum are also paired nuclei of gray matter. In the region of the worm is the core of the tent, in the hemispheres, outward from the core of the tent - an intercalary nucleus, consisting of spherical and cork-shaped nuclei. In the center of the hemispheres is the dentate nucleus, which is involved in the implementation of the function of balance. The defeat of certain nuclei leads to various disorders of motor function. The destruction of the core of the tent is accompanied by a violation of the balance of the body; damage to the worm, corky and spherical nuclei - a violation of the muscles of the neck and torso; destruction of the hemispheres and the dentate nucleus leads to disruption of the muscles of the extremities.

The white matter of the cerebellum consists of various kinds of nerve fibers. Some of them connect the gyrus and lobules, others stretch from the cortex to the inner nuclei, and others connect the cerebellum to other parts of the brain. The last type of fibers forms the lower, middle and upper pairs of legs. As part of the lower legs, fibers from the medulla oblongata and olives stretch to the cerebellum, they end in the cortex of the worm and the hemispheres. The fibers of the middle legs are sent to the bridge. The fibers of the upper legs stretch to the roof of the midbrain. They run in both directions, connecting the cerebellum to the red nucleus and thalamus, as well as to the spinal cord.

Functions of the cerebellum

As mentioned above, the cerebellum provides coordination of movements. With its lesions, various disorders of motor activity and muscle tone develop, as well as autonomic disorders. Cerebellar insufficiency is manifested by muscle atony and inability to maintain body position. So, when a passively hanging limb is displaced, it does not return to its original position, but swings like a pendulum. Purposeful movements are carried out impetuously, with misses past the target.

The characteristic manifestations of cerebellar insufficiency are:

• tremor- fluctuations of small amplitude proceed synchronously in different parts of the body;
• ataxia- violation of the speed and direction of movements, which leads to the loss of smoothness and stability of motor reactions.

Disturbances in coordination of movements in lesions of the cerebellum are explained by its close connection with the brain stem, as well as with the thalamus and sensorimotor area of ​​the cerebral cortex. The cerebellum receives information from various components of the motor apparatus, processes it and transmits corrective influences to the neurons of the brain stem and spinal motor centers. In addition, due to numerous synaptic contacts with the reticular formation, the cerebellum plays a significant role in the regulation of autonomic functions.

Cerebellum- an organ of the central nervous system. The cerebellum is an organ that has connections with other sectors of the brain, the main function of which is.

The cerebellum has a rounded shape, resembling a butterfly, since it consists of two lateral lobes - the cerebellar hemispheres, united in the middle by an elongated central part called the cerebellar vermis. On its surface there are deep grooves starting in the center, going to the peripheral areas and dividing the cerebellum into different lobes, in turn separated by less deep folds. The cerebellum is connected to the brain and spinal cord via the brainstem by three thick bundles of nerve filaments known as the cerebellar peduncles. All sensory and motor information passes through the cerebellum in the brain.

Among the white matter there are some accumulations of gray matter, and they are called the nuclei of the cerebellum. They are located closer to the worm, are paired formations and have a very clear separation:

• serrated nucleus (nucleus dentatus). Located in the center. It looks like a plate with a wave-like bend. Connected to the core of the olive with the help of pathways.
• tent core (nucleus fastigii). It has the most medial location among all the nuclei of the cerebellum.
• globular nucleus (nucleus globosus). It is located more laterally from the core of the tent.
• corky nucleus (nucleus emboliformis). An even more laterally located core, if we take the core of the tent as a starting point.

Different nuclei of the cerebellum formed at different stages of evolution. The core of the tent is considered the most ancient, belonging to the archicerebellum - a part of the cerebellum associated with the balance of the body and, accordingly, having a connection with the vestibular apparatus. Later, a spherical nucleus appeared, and even later, a dentate nucleus and a cork-like nucleus.

Different parts of the cerebellum are responsible for certain functions. There are three functional divisions:

• Archicerebellum- communicates with the nuclei of the vestibular apparatus.
• paleocerebellum- receiving motor commands interprets them into sensory signals. Due to which we are able to adapt the coordination of our actions.
• neocerebellum- cognitive function, as well as the implementation of planning. Each action that we perform must be feasible within a certain time interval - this is achieved through the planning capabilities of the neocerebellum.