Vestibular apparatus - functions. Vestibular apparatus: disorders, treatment

The vestibular apparatus is the receptor section of the vestibular analyzer, located in. Thanks to special cells, the vestibular apparatus determines the position of the body in space, fixes its changes.

The structure of the vestibular apparatus

The receptor apparatus of the organ of balance is located in the thickness of the pyramid of the temporal bone. It combines the membranous semicircular canals and the sacs of the vestibule.

The membranous canals are located inside the bony canals. At the same time, they are smaller in diameter, but completely repeat all the bends of the bony semicircular canals and are attached to their walls with connective tissue strands, inside which the feeding vessels pass.

As a result of this structure, a small space is formed between the bony and membranous parts of the semicircular canals, which is filled by the perilymph, and inside them is the endolymph. These two fluids have a different electrolyte and biochemical composition, but are closely related to each other in a functional sense. They are located not only in the semicircular canals, but also in other parts of the ear labyrinth (cochlea, vestibule) and represent a kind of humoral system.

The bony semicircular canals are part of the bony labyrinth of the inner ear. In the human body, there are three such channels on the right and left sides:

• outer,
• front,
• rear.

According to their orientation in space, the external semicircular canal can be called horizontal (since it is located in the horizontal plane), the anterior canal is frontal, and the posterior canal is sagittal.

The membranous semicircular canals are internally lined with endothelium, with the exception of the ampullae, which contain sensory cells. It is in the ampullae of these channels that there is a rounded protrusion (comb), consisting of supporting and sensitive hair cells. The latter are the end of the peripheral fibers of the vestibular ganglion. The long hairs of these cells are interconnected in the form of a brush, the mechanical irritation of which, due to fluctuations in the endolymph, is fixed by sensitive cells, converted into an electrical impulse and transmitted to the central nervous system.

In the central part of the labyrinth (the bony vestibule) there are two membranous sacs - spherical and epileptic, interconnected by a thin endolymphatic duct. In these anatomical formations, otolith apparatuses are laid in the form of elevations on the inner surface of the sacs, which also consist of supporting and sensitive cells. The hairs of the latter are intertwined with each other, forming a network, and are immersed in a jelly-like mass, in which there is a large number of otoliths (crystals of carbonate and calcium phosphate). With mechanical stimulation, the otoliths exert pressure on the hair cells, which contributes to the formation of electrical impulses.

Thus, the vestibular receptor apparatus consists of five sensory zones, located one at a time in the sacs of the vestibule and the semicircular canals. Peripheral fibers of the vestibular nerve ganglion, which is part of the vestibular analyzer, are suitable for each of these areas. For a better understanding of the functioning of the balance organ, consider the structure of the latter.

The structure of the vestibular analyzer

The vestibular analyzer consists of a peripheral (actually receptor apparatus) and a central section. Its important part is the vestibular ganglion, located in the internal auditory canal, the peripheral processes of which are suitable for sensitive hair cells, and the central ones are part of the vestibular part of the 8th pair of cranial nerves (vestibulocochlear). It is through these fibers that electrical impulses from receptors enter the medulla oblongata and the central nervous system.

The central department of the organ of balance is located in the temporal lobe of the brain. On the way to it, sensory fibers approach a group of nuclei in the medulla oblongata, which enable the vestibular analyzer to form many associative connections. This is the reason for its wide adaptive abilities. The main ones are:

• vestibulospinal,
• cerebellar, oculomotor,
• vegetative,
• cortical.

Such connections cause the development of certain reflex reactions, we will consider them below.

Functions of the vestibular analyzer

The role of the vestibular analyzer is not only to determine the position of the body in space and register its changes, but also to correct them. Adequate stimuli for vestibular receptors are various types of acceleration.

So, angular accelerations are perceived by the sensory cells of the semicircular canals, all types of rectilinear accelerations and vibrational stimuli fix the sensitive cells of the vestibule sacs. In response to mechanical stimuli of this type, various vestibular reactions arise due to the associative connections of the nuclei of the medulla oblongata.

1. Vestibulosomatic (associated with the presence of spinal connections; provide a redistribution of muscle fiber tone).
2. Oculomotor (contribute to the occurrence of nystagmus in the presence of vestibulo-oculomotor connections).
3. Vestibulo-vegetative (changes in blood pressure, heart rate, nausea, vomiting).
4. Vestibulocerebellar (contribute to the redistribution of muscle tone in motion; aimed at maintaining a certain position of the human body in space).
5. Central correction of vestibular reactions (due to connections with the cerebral cortex).

All these reactions are necessary for the body to maintain balance and body position in space, as well as to adapt to changing environmental conditions.

Conclusion

The vestibular analyzer has a rather complex structure, which ensures its normal functioning. The appearance of failures in its work at any level leads to the occurrence of pathological symptoms and the development of the disease.

Neurologist A. Medvedeva says about the vestibular apparatus:

Medfilm "Organ of balance":

vestibular sensitivity the most ancient after the general types of sensitivity. The origin and formation of life on Earth took place under the conditions of the existence of two global factors of the geomagnetic field and gravity. The latter factor had an important influence on the formation of complex organisms due to the need to take into account the gravity vector to implement the antigravitational position of the body.

Functions of the vestibular apparatus

The vestibular apparatus is a sensory organ that perceives, with the help of vestibuloreceptors, changes in the position of the head and body in space, as well as the direction of movement. The vestibular apparatus ensures the balance of the body in a standing position, when walking, running, jumping, while dancing, when going up and down stairs, while swimming, when riding various types of transport, while doing gymnastic exercises, that is, with all movements, when the human body moves from the simplest position to the most complex, the vestibular analyzer (apparatus) appears. If the activity of this analyzer is disturbed, there is a decrease or complete loss of the ability to maintain the balance of the body in space.

The structure of the vestibular apparatus

Vestibulocochlear nerve

The vestibular apparatus has become the main channel signaling the body's position in space relative to the gravitational vector. Vestibular sensitivity is carried out by the vestibulocochlear nerve (VIII pair), which includes two types of reception - vestibular and auditory. The principle of organization is the same as that of the general types of sensitivity, namely: the peripheral part (the receptor neuron with its node and root of the vestibulocochlear nerve) and the central part (in this case, the auditory and vestibular nuclei are homologues of the posterior horns of the spinal cord).

Violation of the functions of the organ of balance occurs as a result of various diseases, injuries and due to the lack of training of this organ from an early age. When accelerating a person’s movements, during rotational, oscillatory movements, while driving, the hypersensitivity of these receptors causes a strong excitation of their nerve centers, which are located in the pons. As a result, dizziness, flickering in the eyes, palpitations may appear, a decrease in blood pressure, blanching of the face, nausea, vomiting, sometimes even fainting can be observed.

With severe damage to this analyzer, a person’s head is spinning even when getting out of bed, “flies” appear before his eyes and nausea, and he is forced to quickly sit down or lie down. With mild injuries to the vestibular analyzer, it is difficult for a person to maintain balance and he feels awkward when performing complex movements - when running fast, jumping, circling, going up and down stairs, etc. Consequently, the main complaint of patients with damage to the vestibular apparatus is dizziness, usually accompanied by ataxia.material from the site

Irritation of the vestibular apparatus causes nystagmus in the direction of the lesion, and its inhibition - in the unaffected side. If necessary, conduct caloric and rotational tests. A caloric test - the infusion of cold (about 20 ° C) water alternately into both ears of a patient - causes horizontal nystagmus in the opposite direction in a healthy person for up to 1 minute. When the vestibular apparatus is damaged, caloric nystagmus drops out or, conversely, intensifies.

A rotational test is performed while the patient is in a special chair. After ten revolutions, the chair is stopped, while the subject develops nystagmus in the direction opposite to rotation, lasting 15-25 s. With damage to the vestibular apparatus, rotational nystagmus falls out or, conversely, increases.

People are moving all the time. Someone does it gracefully, someone clumsily, but any person needs to correctly assess his position in space every moment in order to be able to make the next movement. This assessment is made by the vestibular apparatus - part of the inner ear. For reliability, we have two ears and an apparatus.

The vestibular apparatus is a system of three semicircular canals that evaluates the acceleration that occurs when tilting, turning, or some more complex movement of the head. The operation of this entire system is based on fluid pressure on an elastic membrane. Not the most obvious, but understandable association is a tube filled with water, which is sealed on one side, and on the other side a balloon is pulled over it. If such a tube is tilted up and down, the ball will vibrate periodically.

The constituent parts of the vestibular apparatus are the three semicircular canals, which respond to tilts and turns of the head, and the otolith organ, which responds to acceleration during linear movement.

The semicircular canals are closed and filled with a viscous fluid. At the base of each channel there is a thickening, inside of which there is a cupula - this is such a jelly-like cap. He acts as an oscillating ball on a tube with water. Under the cupula are receptor cells. During the tilt of the head or the whole body in one direction or another, the liquid either presses on the cupula, or does not. The change in the position of the cupula is transmitted to the cilia of receptor cells, which, in turn, transmit this information along the nerves to the brain.

Crayfish also have a vestibular apparatus, but in order for it to work, it must have grains of sand from the river bottom. If you take out these grains of sand from the crab and replace them with iron filings (this can be done when the crab is shedding), and then bring a magnet to the crab, it will think that the bottom is where the magnet is.

The channels are in approximately perpendicular planes, which allows it to respond to tilts in all directions. Since there are two sets of semicircular canals in each head, we can get even more precise information about the position of the head: if the head turns to the right, the receptors in the right horizontal semicircular canal are stimulated, while the receptors in the left horizontal canal are inhibited, and vice versa.

Otolith organs consist of two sacs: round and oval. These sacs are also filled with a viscous fluid, and they also have ciliated receptor cells. Above the cells is a gel-like layer with small but rather heavy calcium carbonate crystals - otoliths. When accelerating in one direction or another, the crystals are displaced and stimulate the cilia of the receptors. Otoliths allow us to feel which is up and which is down.

Why do people get sick

Motion sickness can occur when the vestibular apparatus is overstimulated and the cupula with otoliths continually tug on the cilia of the receptor cells. This sets off a cascade of reactions in the brain, which, among other things, affects the vomiting center. The vestibular apparatus can be trained - and any sport will do here, except for chess - there will be less motion sickness.

But alcohol intoxication does not affect the vestibular apparatus. An unsteady gait is the result of the breakdown products of alcohol affecting the cerebellum, which is responsible for maintaining balance.

Most people in the world know what the vestibular apparatus is. But, unfortunately, not everyone understands what a vital function it carries in itself. Such an irreplaceable part of our body is responsible for balance, coordination, orientation of the body in space, as well as partial work of vision, hearing and general sensitivity in the body. The structure of the organ is located in such a way that the main part of it is in the inner ear, but the main work still takes place in a specific part of the brain - the cerebellum.

The basis of the whole device- this is the concentration of ciliated cells in the inner ear, endolymph, as well as otoliths (specific calcareous formations) and jelly capsules in the ampullae of the semicircular canals.

human vestibular apparatus gives signals of two types: statistical (often they are associated with the position and coordination of the human body in space, finding its individual parts) and dynamic (movements associated with acceleration). The whole work looks like this: mechanical irritation of the hairs occurs, as a result of which a signal of a certain type enters the human brain, and after analysis, the brain gives the appropriate command to the muscles. And all this in a fraction of seconds. In other words, there is a coordination of human muscles, which makes it possible for the body to orient itself in space. If we make a rather rough comparison with human technology, then the gyroscope is the most suitable tool for this.

Vestibular disorders

Causes of violation of the vestibular apparatus is a malfunction of the cerebellum. Dysfunctions often appear if there are vascular, inflammatory diseases of the nose, ears or eyes (including disorders of the inner ear), trauma, Eustachian tube dysfunction, viruses and infections, as well as diseases of bacteriological etiology. As you know, the ear is not a hermetic organ, hence it follows that even if such a small part of everyday life as thorough hygiene is missing, vestibular disorders can occur. Therefore, special attention must be paid to water procedures and drying of the ear canal.

Problems and diseases of the vestibular apparatus

In other cases, it is impossible, at first glance, to determine the symptoms of a violation of the vestibular apparatus. The problem is not visible to the naked eye, appears only in certain situations or by conducting simple physical exercises, tests. A special risk group that is prone to various dysfunctions of an important organ is people over 60. This happens not only because at this age the risk of ENT diseases increases significantly, but also because of a general deterioration in immunity and wear and tear of the body.

Vestibular disorders of the apparatus can give out a symptom, or even symptoms, such as:

are present and psychosomatic phenomena, such as:

• panic;
• increased heart rate;
• increased heart rate;
• sweating of the hands;
• desire to hide in the far corner;
• violation of blood pressure;
• a sharp change in complexion (blanching, redness);
• increased salivation.

Man simply cannot control his brain. It seems to him that he is about to fall, he is terribly afraid of flying. The escalator causes panic horror. Symptoms often occur unexpectedly, characterized by both constant and erratic time intervals between manifestations of the disease.

Symptoms may appear for any of the following reasons:

1. Sharp aromas.
2. Motion sickness in any of the modes of transport.
3. Syndrome of vertebrobasilar insufficiency.
4. Increase in blood density.
5. Ear edema.
6. Head injuries, including craniocerebral.
7. Taking medications, including chemical or antibiotics.
8. body intoxication.
9. Vestibular neuritis.

And also the cause of violations of the vestibular apparatus can be acquired or congenital diseases of the cardiovascular, nervous system.

Diseases of the vestibular apparatus

Vestibular neuritis

The main syndrome found in a number of diseases of the vestibular apparatus. One of the most common causes of disorders of the vestibular apparatus is damage to the vestibular nerve. It can occur at any age, often the cause of the disease can be an infection of the nasal cavity, upper respiratory tract, as well as ears and throat.

Neuritis is accompanied by the following syndromes:

• dizziness;
• nausea, with possible repetitions.

Recovery of the organ responsible for balance occurs quickly and, in most cases, successfully.

Blockage of the internal labyrinthine arteries

The most dangerous dysfunction of the coordinating organ is characterized by an imbalance in the blood supply to the brain, which leads to a lack of nutrition, oxygen starvation, and in especially difficult cases, to cerebellar damage caused by a stroke or heart attack. The main symptom of the disease is dizziness. And also deafness (partial or complete), as well as loss of orientation in space, can be observed.

Meniere's disease.

The disease is often diagnosed by symptoms such as a scheduling or buzzing sound, infrequent dizziness, nausea, and in special cases, clouding of consciousness. Often the disease is bacterial, viral or infectious. The action itself takes place in the membranous labyrinth.

Benign positional vertigo

It occurs more often in the elderly, but can occur at any age. Most often, before such a disease, a person suffers from ear, nose, and throat diseases, but often the exact cause of the disease is unknown. Vertigo, comes on in short attacks, repeated every time there is a change in position of the body in space.

Vestibulopathy

The disease is characterized by many dysfunctions of the vestibular organ, the main and most frequent manifestation of which is the lack of coordination of a person in space. The disease can be considered both separately and in conjunction with other characteristic failures in the body. Treatment of vestibulopathy is complex and often has a favorable outcome, especially with early diagnosis of the disease.

Chronic bilateral vestibulopathy.

Vestibulopathy manifests itself as a slowly growing dysfunction of stability and moderate, but stable (when compared with partial) vertigo. Most often, the disease is associated with poisoning with ototoxic drugs.

Vertebral - basilar insufficiency

In old age, after displacement or any other movement of the head, there is a feeling of rotation or fluctuation in the eyes, nausea, infrequently, pain can radiate to the stomach. All these are symptoms of the disease. Not only the device itself is treated, but also the cardiovascular system. People with existing cardiovascular diseases who have undergone operations on the cardiovascular system often suffer from vertebrobasilar insufficiency.

post-traumatic dizziness

Occurs subsequently after traumatic brain injury, as well as concussion, and any other head injuries or fracture of the temporal bone.

Infectious and viral diseases of the ear

Diseases carry a direct threat to the vestibular apparatus simply because the risk of complications to a nearby organ is very high. Which directly affects the state.

Vestibular dysfunction

Occurs when the vestibular nuclei do not work properly. Most often, dysfunction is confused with a variety of ailments of the vestibular apparatus, simply because dizziness is the most common symptom. Subsequently, appeals to a specialist, most often the patient is provided with vestibular resuscitation.

Treatment and training of the vestibular apparatus

Often, many complications that can be associated with an organ-balance, can be improved by training. Treatment of disorders or even diseases depends on the severity and neglect of the situation. If you notice one or more of the symptoms of the disease, you should immediately consult a doctor. In this case, an otolaryngologist will help.

The specialist will help you understand the causes of your illness, conduct an examination and provide the necessary assistance. Additional tests will be assigned to you in order to rule out a misdiagnosis. After a detailed diagnosis, you will be assigned a unique therapy suitable only for your disease. Treatment of the vestibular apparatus is always complex, often requiring long-term rehabilitation after.

How to improve the vestibular apparatus?

Weak vestibular apparatus is not only possible, but also needs to be strengthened. For this, certain exercises are suitable, aimed at improving coordination and increasing the sensitivity of the body. A set of tasks aimed at the formation of strong muscles, an adequate analysis of nerve endings, as well as psychosomatic well-being was developed back in the distant 30s.

The vestibular apparatus of a person is located in the inner ear, it is responsible for the ability of a person to correctly navigate in space and maintain balance. If the functions of the vestibular apparatus are disturbed and it ceases to perform them adequately, then the person loses tactile (skin) sensitivity, he cannot normally navigate in space, since his visual and surrounding world is disturbed.

How is this organ arranged?

This apparatus is an organ of balance, when a person makes any head movements, the receptors of the vestibular apparatus are irritated, while the muscles contract reflexively, which allows you to maintain body position and balance. Human physiology has its own characteristics, therefore, in addition to this apparatus, vision and skin (tactile) sensitivity are also used for orientation in space.

If we talk about how the vestibular apparatus works, then it works on the principle of a gyroscope and, with the help of special receptors, it detects any change in the position of the head, after which the position of the body is corrected.

Ampoules are located in the temporal part of the head, they are filled with a special liquid in which calcareous formations (otoliths) are immersed. Tilt of the head causes the fluid to shift, causing the otoliths to move as well. The structure of the vestibular apparatus provides that, after moving, the otoliths begin to irritate the ciliated cells, which are part of the nervous system, and thus the signal about a person's change in body position is transmitted to the brain.

Further, the scheme of work is as follows: after the signal has entered the corresponding part of the brain, the muscles receive a signal from there to perform certain actions, and thus a stable position of the body is achieved. Now you know how the vestibular apparatus works and where it is located, human physiology is known and what components are part of the vestibular apparatus.

Despite the fact that this is an accurate and reliable system, under the influence of various negative factors, failures in its well-functioning operation may occur.

Symptoms of violations

In humans, the vestibular apparatus is located in the inner ear, it has several departments, and depending on which of them has been disturbed, different symptoms will appear.

The main signs that there are violations in the operation of this device:

• a person becomes dizzy;
• his eyes begin to perform oscillatory movements.

These will be direct symptoms, in addition to them, accompanying signs of disorders that have arisen may develop:

• nausea can be of varying intensity, and often it ends in vomiting;
• the skin of the face and neck may become red or very pale;
• a person cannot keep balance;
• he has impaired coordination of movements;
• increased sweating begins;
• heart rate is disturbed;
• respiratory rate is disturbed;
• blood pressure is disturbed.

In various cases, such symptoms can either be present constantly or appear suddenly, most often it occurs paroxysmal. Various reasons can project the development of such attacks, for example, a sharp sound or smell. Such a reaction may occur to changes in weather conditions, and other factors may also influence this. Between such attacks, a person usually feels normal, and does not feel any discomfort.

Reasons for the development of disorders

There are many reasons that can lead to malfunctions of this system: diseases of the inner ear, injuries, the development of neoplasms, inflammation, viruses and infections.

In many people over 60 years of age, when changing the position of the head, the illusion of rotation often occurs, while nausea and vomiting may appear, and in some cases pain will be in the stomach. The most common cause of this is a respiratory infection, but it can also be the result of a post-traumatic or post-operative condition.

Viral diseases can cause vestibular neuritis, which in most cases leads to a breakdown in the operation of this apparatus. A person is dizzy, nausea is almost always accompanied by vomiting, the eyeballs begin to spontaneously move in a circle or in a horizontal direction. Usually the most severe symptoms are observed within 3-4 days, in young people recovery occurs in a few weeks, and in the elderly this process can take several months.

After 60 years, there is a high risk of developing signs of vertebrobasilar insufficiency, in such cases, not only the vestibular apparatus is treated, but also the cardiovascular system.

The cause of its development will be disturbances in the work of the vestibular nerve, cerebellar stroke or the development of vascular ischemia in the inner ear.

In addition to the fact that a person is dizzy and balance is disturbed, his vision begins to double, speech becomes incoherent. If such symptoms continue for a long time, then this is not a syndrome of vertebrobasilar insufficiency, which passes quickly enough, and the person needs to clarify the diagnosis.

Blockage of the internal auditory artery can occur, and this is very dangerous for the vestibular apparatus. This entails impaired blood supply to the brain, which often leads to the development of cerebellar stroke and heart attack, and the development of cerebral hemorrhage can be fatal.

If poisoning has occurred with drugs that have an ototoxic effect, then bilateral vestibulopathy may develop.

Other causes of malfunctions of the vestibular apparatus

One of the most common is, in this case, dizziness will either increase or subside. This happens in attacks, hearing worsens and its gradual loss occurs, constant noise and congestion appear in the ears.

The cause of the violations can be ear diseases such as sulfur plug, otosclerosis, in which the bone capsule is affected. The work of the auditory tube may be disrupted due to allergies, polyps, trauma to the temporomandibular joint, and this may also cause the development of otitis media.

When receiving a traumatic brain injury, a fracture of the temporal bone or a concussion of the labyrinth may occur, which will cause a malfunction of the vestibular apparatus, which is located in this part of the head.

In some cases, a sign of the development of a migraine in a person may not be pain, but dizziness in the form of periodic attacks, usually teenage girls suffer from this, such people are prone to motion sickness in transport.

The reason for the failure of this system may be epilepsy. In rare cases, this can lead to the development of a tumor of the cerebellopontine angle, while gradually, and in some cases abruptly. Usually, neoplasms grow due to various forms of neurofibromatosis, while light brown spots appear on the skin.

Many people have impaired coordination of movements and dizziness due to craniovertebral pathology. In this case, a person’s speech and swallowing function may be impaired, and the eyeballs also begin to move. Most often it occurs in childhood.

Carrying out diagnostics

The treatment of such disorders should begin with the fact that the cause of their appearance is first determined, and the problems that have arisen should be addressed to an otolaryngologist. First, the doctor will conduct an examination, after which a hearing level measurement, ultrasound and brain tomography using modern computer technology can be prescribed.

In any case, if you notice that your vestibular apparatus is not working properly and have found the described symptoms, then be sure to consult a doctor, and do not self-medicate. The use of modern diagnostic methods allows the doctor to accurately diagnose, after which he will be able to prescribe an effective treatment that allows you to remove the causes that led to disturbances in the functioning of the vestibular apparatus and cure the person.