Vestibular apparatus disorders: symptoms and treatment. Vestibular apparatus in the body - functions, poor coordination and training at home

Together with the visual and motor receptor systems (a receptor is an anatomical formation that converts perceived irritation into nerve impulses), it plays a leading role in a person’s orientation in space. Vestibular apparatus perceives information about acceleration or deceleration that occurs during any type of movement, as well as when the position of the head in space changes. The sense of gravity is also analyzed here, which is why the vestibular apparatus is also called the organ of gravity. Under resting conditions, the receptors of the vestibular apparatus are not excited. Irritation of the receptors occurs when the head is tilted or moved. In this case, there arise reflex contractions muscles that help straighten the body and maintain balance.

Labyrinth
The vestibular apparatus is located inside temporal bone and is closely connected with the organ of hearing. In the thickness of the temporal bone there is a complex labyrinth, which is a system of interconnected canals and cavities. There is a bone labyrinth and a membranous labyrinth located inside it, which has a connective tissue wall and basically repeats the shape of the bone labyrinth. Between the bony and membranous labyrinths there is a gap filled with fluid - perilymph. The membranous labyrinth is filled with dense endolymph, the viscosity of which is 2-3 times greater than that of water.

The labyrinth contains the vestibule and semicircular canals, in which the vestibular receptors are located, as well as the cochlea, where the auditory receptors are located. There are three semicircular canals, and they lie in mutual perpendicular planes, which allows you to analyze the position in three-dimensional space. Each semicircular canal has two legs, one of which expands in front of the vestibule, forming an ampulla. The vestibule is an oval cavity into which the semicircular canals open on one side and the cochlea on the other.

In the corresponding bony semicircular canals lie the membranous semicircular ducts; in the vestibule there are membranous spherical and elliptical sacs. In the semicircular ducts and vestibular sacs there are clusters of receptor cells. Vestibular receptors are located on elevations, which are present only in the ampoules of the ducts in the form of scallops and in the sacs in the form of spots. The fluid contained in the labyrinth moves when the head and body move (first perilymph, and then endolymph) and irritates the receptor cells. The latter in the ampoules of the semicircular ducts are excited during the movement of the endolymph, mainly during angular accelerations, and in the spots of the sacs - during linear accelerations.

Receptor cells
In the spots, the part of the receptor cell protruding into the cavity of the sac ends in one longer mobile hair and 60-80 glued fixed hairs. These hairs are immersed in a jelly-like membrane containing calcareous crystals - otoliths. The receptor cells of the spots are irritated due to the sliding of the otolithic membrane along the hairs during the movements of the endolymph. The sensitivity of receptor hair cells is high: the threshold for distinguishing head tilt to the side is only about 1°, and forward and backward - 1.5-2°. When the rotation accelerates, a person notices a change of 2-3° per 1 s2.

It is believed that receptor cells in the spots of the sacs perceive the force of gravity and primarily regulate the balance of the head and body at rest (static balance), and the receptors in the ampullae of the semicircular ducts react to acceleration or deceleration of movement, that is, they regulate the balance of the body moving in space ( dynamic equilibrium).

Transmission of nerve impulses

Nerve impulses arising in the receptor cells of the vestibular apparatus are transmitted along the sensory nerve fibers of the VIII pair cranial nerves into the brain and first enter the vestibular centers medulla oblongata. From here, signals are sent to many parts of the central nervous system: the spinal cord, cerebellum, cerebral cortex, oculomotor nerve nuclei, reticular formation and autonomic nuclei.

Thanks to connections with the spinal cord, vestibular reflexes are carried out to maintain body balance, which involve the muscles of the neck, torso and limbs. As a result of these reflexes, the muscle tone and balance is maintained. Connections with the cerebellum give movements smoothness, precision and proportionality.

Signals that are sent from the vestibular centers to the nuclei of the oculomotor nerves make it possible to maintain the direction of gaze when changing the position of the head. This also explains nystagmus in cases of imbalance - involuntary rhythmic movements eyeballs in the opposite direction to rotation, followed by their spasmodic movement back. The characteristics of nystagmus serve as an important indicator of the state of the vestibular apparatus, therefore they are analyzed in aviation, marine and space medicine, and studied experimentally and clinically.

Autonomic reactions

Through a set of nerve structures located in the central parts of the brainstem (medulla oblongata and midbrain, visual thalamus) vestibular reactions are involved the cardiovascular system, gastrointestinal tract and other organs. With strong and prolonged loads on the vestibular apparatus, autonomic reactions occur in the form of a slowdown in heart rate, decreased blood pressure, dizziness, nausea, vomiting, cold hands and feet, pale face, cold sweat, etc. Similar symptoms are possible with seasickness, going up in a high-speed elevator. This is due to the fact that a person is accustomed to movements in the horizontal plane, but movements up and down or to the sides are unusual for him. Specific training (swing, rotation) and application medicines reduce the excitability of the balance organ and prevent undesirable phenomena.

State of weightlessness

In a state of weightlessness, the activity of the vestibular apparatus changes: in the first 70 hours, the activity of the vestibular receptors sharply decreases, and then increases and after a few days returns to normal. However, the lack of stress on the musculoskeletal system reduces impulses from the muscles and can cause disorders vegetative functions Therefore, during a long stay in a state of weightlessness, special muscle exercises must be performed.

Spatial orientation

IN normal conditions spatial orientation is ensured by the joint activity of the vestibular apparatus and vision. However, the vestibular apparatus helps the body navigate in space both during active movement and during passive transfer from place to place blindfolded. With the help of the vestibular apparatus and the cerebral cortex, the direction of movement, turns and distance traveled are analyzed and remembered. Clinical observations indicate that the loss of vestibular function in a person (for example, as a complication of meningitis) causes instability of posture and at the same time makes him not susceptible to seasickness. In deaf and mute people, the vestibular apparatus does not function and they feel a tilt of the head due to contraction of the neck muscles.

The vestibular apparatus is in close interaction with the visual and propulsion systems, which ensures a person’s orientation in space, maintaining balance and coordination of movements.

People are moving all the time. Some do it gracefully, others clumsily, but every person needs to correctly assess their position in space every moment in order to be able to make the next movement. This assessment is made by the vestibular apparatus - part inner ear. For reliability, we have two of both the ear and the device.

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 is pulled over it balloon. If such a tube is tilted up and down, the ball will periodically vibrate.

The components of the vestibular apparatus are 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 viscous fluid. At the base of each canal there is a thickening, inside of which there is a cupula - this is a jelly-like cap. It acts as an oscillating ball on a tube of water. Under the cupula there are receptor cells. When the head or the whole body is tilted in one direction or another, the liquid sometimes presses on the cupula, sometimes it does not. A 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.

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

The channels are in approximately perpendicular planes, allowing them to respond to tilts in all directions. Because there are two sets of semicircular canals in each head, we can obtain 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.

The otolith organs consist of two sacs: round and oval. These sacs are also filled with a viscous fluid, and they also contain receptor cells with cilia. Above the cells is a gel-like layer with small but rather heavy crystals of calcium carbonate - otoliths. When accelerated in one direction or another, the crystals shift and stimulate the receptor cilia. Otoliths allow us to sense where is up and where is down.

Why do people get motion sickness?

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

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

What is the vestibular apparatus? The vestibular apparatus is an integral part of the inner ear; it is a special organ that recognizes the location of the head and torso in space. The vestibular apparatus is a special sensitive receptor vestibular analyzer.

A large number of accumulated ciliated cells in the inner ear form the vestibular apparatus. Special impulses go to the brain from the vestibular apparatus, transmitted along the branches of the nerve responsible for hearing, which depend not only on the location of the body, but also on the acceleration of the body in space. When the human body moves, the otolithic membrane shifts at the tips of the receptor cells. For us, this is the perception that we are moving in space. Also, the otolith apparatus, located in the inner ear, helps us feel the position of rest, in other words, this sensation can be called static. In the endolymph cavity there are brushes belonging to the ampullary apparatus. The ampullary receptor mechanism itself has its localization in the cavities of the ampullae of the cupule. With angular movement and rotational movement, the process of mobility of the brushes occurs. When five nerve receptor endings belonging to the vestibular apparatus are excited, the human body experiences as much spatial movement as possible.

Functions of the vestibular apparatus

The function of the vestibular apparatus in the human body is very important. The vestibular apparatus transmits impulses using the vestibular branch. The nerve nuclei of the vestibular apparatus are connected with the nerve nuclei located in the cerebellum, as well as with clusters nerve fibers third pair of cranial nerves and, in fact, with the centers of the autonomic nervous system. Also higher cortical centers, belonging to the vestibular apparatus have their localization in the parietal lobes. If the receptors of the vestibular apparatus are irritated, the human body instantly experiences certain changes - this is a function of the vestibular apparatus. Namely, there is a sharp change in the tone of the muscles belonging to the torso, neck, arms and legs. In the human body, a response to stimuli occurs in order to maintain the location of the body and its balance in space. If the irritation coming from the vestibular apparatus is very strong, then the so-called special symptom of motion sickness develops in the human body, which occurs in motion sickness. That is, the light appears first, then the strong; nausea, and subsequently vomiting; shortness of breath; the body seems to be in shock.

However, impulses that often enter the brain from the vestibular system can be significantly weakened. With such constant manipulations, the human body is able to get used to them. Exist special methods apparatus training, they are used to train specialists such as sailors, astronauts, pilots, etc. That is, for people experiencing particularly strong vestibular stress.

The vestibular apparatus of many animals can easily become confused, as a result of which the animal simply loses its position in space. You can rotate the animal for a while, after which it will feel that the earth is moving away from under its feet. The same thing happens to a person. Remember how we used to play drunken people when we were kids? At first we spun around in space for some time, and then we became dizzy and could not walk smoothly. The vestibular apparatus of a person who is in weightlessness, that is, in space, is represented only by a vision analyzer. The vestibular apparatus always relies on the visual field.

Disorders associated with the functioning of the vestibular apparatus

Various types of disorders of the vestibular apparatus are possible, in which its function is not fully fulfilled. When it is violated, symptoms appear when you feel dizzy and the eyes pulsate in an oscillatory manner. The chaotic direction of eye movements occurs due to the fact that the endolymph makes movements in the labyrinth of the membranous structure, while certain receptor endings that directly belong to the vestibular apparatus are excited; they are directly connected to the nerve bundles, namely, the third pair of cranial nerves, this process Ewald proved it experimentally. Associated symptoms- a movement disorder profuse sweating, change in body color, the ability to balance is significantly lost, that is, a person cannot stand exactly on one leg. Such symptoms may occur unexpectedly or constantly (in more complicated situations). The reasons for the sudden onset of symptoms may be strong odors, sounds, even the weather. The human body instantly responds unfavorably to such stimuli.

The function of the vestibular apparatus can be tested using a simple, fast and most accurate method. Stand on two legs, place your hands on your waist, bending your elbows. Next, we bend the other leg and move it to the side so that it is opposite the other leg (on which the entire body weight is concentrated), we compare the foot with knee joint. We close our eyes. A partner should help you; he should note the time on a stopwatch and measure how many seconds you stand in this position. After changing your position, your partner must press the stop button on the stopwatch. For 8 years normal time standing - 8.3 sec; for 9 - 10.8 sec; for 10 - 12.7 sec; 11 - 14.4 sec; 12 - 15.5 sec; 13 - 6.9 sec; 14 - 17.7 sec; for 15 - 17.8 seconds; over 15 years of age, the norm will be 20.4 seconds.

If suddenly your indicators are significantly different, then you should exercise.

If, at least once in your life, you took pills for motion sickness or went down the steps of an attraction with the promising name “Surprise” while shaking, then, alas, you will not be able to become a follower of Valentina Tereshkova.

The reason for this is the hypersensitivity of the vestibular apparatus, which can ruin the life not only of those dreaming of the glory of an astronaut, but also of those who use a car, bus, elevator and other benefits of civilization.

Why we need the vestibular apparatus, how it works and whether it is possible to avoid malfunctions in its operation, we tried to explain in our article “ vestibular apparatus«.

The importance of the vestibular apparatus

With its unpronounceable name vestibular apparatus must Latin word vestibulum, which translated means “vestibule” (a hint of location in the vestibule). True, it has only an indirect relation to the organ of hearing: the task of the vestibular apparatus is to analyze not sounds, but the slightest changes in the position of the head and body. Very sensitive to the Earth's gravitational field, this complex sensory system allows you to navigate in space and maintain balance even with your eyes closed.

By the way, the destruction of the semicircular canals of the vestibular apparatus causes serious problems in the spatial orientation of humans, birds and animals. A pigeon, for example, after such an injury will never be able to fly, and guinea pig will spin in one place, unable to get out of the maze.

Disturbances in the functioning of our vestibular apparatus primarily affect the gait; it becomes unsteady, and a person can fall for no reason. In addition, many may complain of constant dizziness, nausea, motion sickness in transport, increased heart rate, and increased blood pressure.

Structureand functions vestibular apparatus

If you shrink down to the size of a speck of dust and examine the vestibular apparatus from the inside, you will find that it is part of the inner ear, often called the labyrinth. Located in the bony recesses of the vestibule of the inner ear and its semicircular canals, the vestibular labyrinth is partially filled with jelly-like endolymph covering its sensory villi.

Under the influence of gravity, the endolymph and the calcareous pebbles (otoliths) floating in it crush certain villi, as a result of which information about changes in body position is transmitted to the brain. In a split second, having processed the received data, the brain gives an “instruction” to change the tone of the muscles, torso, and legs so that we can maintain balance in any situation.

And here's what's interesting: human vestibular apparatus configured to move in the horizontal, but not in the vertical plane. This is why many people experience severe dizziness and nausea.
People with poorly trained vestibular apparatus should take with them long trip Aeron or an analogue of this drug, which reduces the sensitivity of the sensory system. True, you shouldn’t abuse such pills - they are addictive.

He has SUCH connections!

Despite the fact that the vestibular apparatus is located deep in the temporal bone, it is aware of more than just the position of the head. Information about absolutely all muscles, organs and systems flows to it via nerve endings.

It maintains particularly strong connections with the oculomotor nerves, gastrointestinal tract, cardiovascular and vegetative nervous systems. That is why, at the slightest change in blood pressure or increased heart rate after the experience, we feel dizzy.

How to train the vestibular apparatus

Most people are not even aware of the existence of the vestibular apparatus in their body. These lucky ones include those who, from childhood, trained their sensory system by spending hours on swings, playing football, tumbling on the horizontal bar and spinning like a top at every opportunity. If you were more attracted Board games, then there is a high probability that the hypersensitive and capricious vestibular apparatus will bring you to a semi-fainting state while walking on a yacht or descending a mountain serpentine road.

However, experts are confident that the vestibular apparatus can be trained at any age - to do this, it is enough to perform bends, turns and smooth rotations of the head and torso every day. You need to start very carefully, limiting yourself to 2-3 repetitions, gradually increasing their number to 6-8. However, most best workout Experts consider jogging, aerobics and swimming to help improve the vestibular system. Lazy citizens can strengthen their balance system through passive activities, such as slowly swinging in a hammock or rocking chair.

Vestibular disorders

Experts warn: healthy person should neither “drive” nor rock. Such symptoms are a reason to be wary and pay a visit to an otolaryngologist-vestibulologist, who will help to find out the causes of disturbances in the functioning of the vestibular apparatus.

Most often the culprits of failures are cardiovascular disorders, sharp and chronic inflammation inner ear and cranial nerves. Does not like the organ of balance and scoliosis, vertebral hernias- all these diseases worsen blood microcirculation in the vestibular apparatus, as a result of which it receives less useful substances and oxygen.

What the vestibular apparatus likes and dislikes

P.S. Lastly, take a look. interesting cartoon Smeshariki, vestibular apparatus

Dear blog readers, what do you think a person needs? vestibular apparatus, leave comments or reviews. This will be very useful for someone!

Vestibular apparatus participates in maintaining the balance necessary for orienting the human body in space. With any change in body position, the receptors of the vestibular apparatus are irritated. The resulting nerve impulses are transmitted to the brain to the appropriate centers.

The vestibular apparatus consists of two parts (Fig. 97): bony vestibule And three semicircular ducts(channels). Located in the bony vestibule and semicircular canals membranous labyrinth, filled with endolymph.

Rice. 97. Structure of the organ of balance:

1 - vestibule, 2 - semicircular canals, 3 - spherical sac, 4 - elliptical sac, 5 - endolymphatic duct, 6 - spot of the spherical sac, 7 - otolithic apparatus, 8 - supporting cells, 9 - sensory hair cell, 10 - statoconia, 11 – statoconia membrane, 12 – lateral semicircular canal, 13 – anterior semicircular canal, 14 – posterior semicircular canal, 15 – ampulla, 16 – ampullary crest, 17 – sensory hair cells, 18 – dome

Between the walls of the bone cavities and the membranous labyrinth, which follows their shape, there is a slit-like space containing perilymph. The membranous vestibule, shaped like two sacs, communicates with the membranous cochlear duct. Three openings open into the membranous labyrinth of the vestibule membranous semicircular canals - anterior, posterior and lateral, oriented in three mutually perpendicular planes. Front, or superior, semicircular the canal lies in the frontal plane, rear – in the sagittal plane, external – in the horizontal plane. One end of each semicircular canal has an extension - ampoule. On the inner surface of the membranous sacs of the vestibule and the ampoules of the semicircular canals there are areas containing sensitive cells that perceive the position of the body in space and imbalance.

On inner surface membranous sacs are arranged in a complex arrangement otolith apparatus, dubbed spots(see Fig. 97). The spots, oriented in different planes, consist of clusters of sensitive hair cells. On the surface of these cells, which have hairs, there is a gelatinous statoconia membrane, which contains crystals of calcium carbonate - otoliths, or statoconia. The hairs of the receptor cells are immersed in statoconia membrane.

In the ampoules of the membranous semicircular canals, accumulations of receptor hair cells look like folds, called ampullary scallops. On the hair cells there is a gelatin-like transparent dome that does not have a cavity (see Fig. 97).

Sensitive receptor cells of the sacs and scallops of the ampullae of the semicircular canals are sensitive to any changes in the position of the body in space. Any change in body position causes movement of the gelatinous membrane of the statoconia. This movement is perceived by hair receptor cells, and a nerve impulse is generated in them.

Sensitive cells of the spots of the sacs perceive gravity and vibration vibrations. In normal body position, statoconia press on certain hair cells. When the position of the body changes, statoconia exert pressure on other receptor cells, new nerve impulses arise that enter the brain, into the central sections of the vestibular analyzer. These impulses signal a change in body position. Sensory hair cells in the ampullar ridges generate nerve impulses during various rotational movements of the head. Sensitive cells are excited by the movements of the endolymph located in the membranous semicircular canals. Since the semicircular canals are oriented in three mutually perpendicular planes, any turn of the head will necessarily cause the endolymph to move in one or another canal. Its inertial pressure excites receptor cells. The nerve impulse generated in the receptor hair cells of the macula sacs and ampullar ridges is transmitted to the following neurons, the processes of which form the vestibular (vestibular) nerve. This nerve along with auditory nerve exits the pyramid of the temporal bone through the internal ear canal and goes to the vestibular nuclei located in the lateral sections of the bridge. The processes of the cells of the vestibular nuclei of the bridge are sent to the cerebellar nuclei, motor nuclei of the brain and motor nuclei of the spinal cord. As a result, in response to stimulation of the vestibular receptors, the tone of the skeletal muscles reflexively changes, and the position of the head and the entire body changes in the required direction.