What are the consequences of poor hearing hygiene? Hygiene rules for vision and hearing. Teacher assessment of children's work

Hearing is one of the most important feelings that nature has endowed man with. The ability to hear is not only the ability to communicate with others like you. It is also our security: thanks to our hearing, we can quickly react to danger and avoid it, catching the “threatening” and warning sounds of the external environment (the noise of a moving car, barking of a dog, the sound of breaking glass, etc.).

If, in addition, we take into account the complications on the eyes and the brain that are possible with diseases of the hearing organs, it becomes obvious: preserving hearing and maintaining the health of our "acoustic system" is one of the most important conditions for a prosperous and long life.

Risk factors

The list of factors and conditions that can lead to a decrease in hearing acuity can be roughly divided into three categories.

Household

A special danger of domestic injuries lies in their "accessibility" to a person of any age, gender and social status. For example, accidents can be prevented by avoiding roads and vehicles, but everyday life cannot be eliminated.

What threats can lie in your own home?

• any thin and sharp objects with which it is so "convenient" to clean the ear canal. According to statistics, 78% of cases of perforation of the eardrum are the result of cleaning the ears with objects that are not intended for this. Cotton swabs are no less dangerous: with their help, only a small part of the earwax is extracted, and the bulk moves to the eardrum, eventually creating a sulfur plug;
• any small rounded objects (beads, plant seeds, pills, etc.) that young children think will look great in the nose or ear canal. About 14% of cases of purulent otitis media and tubo-otitis in children develop due to such foreign "decorations".
• water that can enter the ear canal during bathing and not leave it until drastic measures are taken. Do not assume that the longer the water is in the ear, the better it will wash it - this will only lead to ear congestion and an increased risk of infection entering the ear canal.

Professional

The increased noise level is the main threat that lies in wait for us in production conditions. At the same time, it is not necessary to be an employee of a metallurgical plant to be under the influence of unhealthy decibels. A printing house, a recording studio, a taxi or airport control tower - any workplace equipped with professional equipment that creates a "soundtrack" is a risk factor for hearing health.

But the absence of noise also does not mean that your work is completely safe. Professional swimmers and divers, divers, pilots and flight attendants are regularly exposed to unwanted pressure on the eardrums. Barotrauma, in which the eardrum is deformed or damaged, is the main occupational disease among people of these professions.

Working with harmful substances (derivatives of benzene and acetone, mercury, arsenic, chlorine and other gases) means that a person is at risk for toxic lesions of the auditory nerve. Developing very slowly and gradually, neuritis of the auditory nerve begins to manifest itself seriously when the changes become irreversible.

Medical

Inflammatory diseases of the hearing organs differ in that their development is, as a rule, a complication of another disease. Otitis media, eustachitis, labyrinthitis and other pathologies of the outer, middle and inner ear often occur after rhinitis, tonsillitis, ARVI, etc.

In fact, any disease in which there is swelling of the nasopharynx (even a "habitual" allergic rhinitis) is a risk factor, since swelling of the nasal mucous membranes disrupts the outflow of fluid from the auditory tube, which provokes excessive pressure on the eardrum. Stagnation of fluid, in turn, creates a favorable environment for the multiplication of pathogens, which can cause ulceration of mucous membranes, their atrophy and cause intoxication of the whole organism, including the brain.

Another medical risk factor is the familiar antibiotics. Some drugs in this group have toxic effects that can affect the health of the auditory nerve.

Healthy rules

To keep your hearing and overall health healthy, there are a few tips to follow:

• To cleanse the ear canal from earwax, use special products that can be purchased without a prescription at the pharmacy. Use these drugs according to the instructions, once every 3-4 weeks.
• If you like listening to music through headphones, please note: sounds from the headphones that are heard by the person next to you mean that you have chosen the wrong volume and this threatens you with ruptured eardrums.
• When coming into contact with toxic substances at work, be sure to use protective masks and goggles, wear protective clothing that prevents chemicals from getting on your skin. Follow the same rule at home: when using paints and varnishes, fertilizers, herbicides, etc., take precautions even if the package with the chemical indicates that it is harmless.
• Everyone knows about timely access to a doctor and adherence to bed rest during ARVI. But if after recovery, ear congestion persists, you are worried about noise or ringing in the ears, do not delay a visit to the doctor, since the listed symptoms signal pathological processes in the auditory tube and the middle ear cavity.
• Never self-medicate, especially if it includes heat treatments and antibiotics. In case of purulent inflammatory processes in the cavity of the middle and inner ear, warm compresses accelerate the penetration of infection into the orbit and brain. And unreasonable and uncontrolled use of antibiotics can significantly complicate the treatment of ear disease and lead to irreversible damage to the auditory nerve.
• Treat dental diseases in a timely manner: caries, periodontal disease, gingivitis, stomatitis create a favorable environment for the reproduction of pathogens, which can subsequently enter the ear cavity through the auditory tube.

5.1. Understanding analyzers

An analyzer (sensory system) is a part of the nervous system, consisting of many specialized perceiving receptors, as well as intermediate and central nerve cells and nerve fibers that connect them. For sensation to occur, the following functional elements must be present:

1) receptors of the sense organ that perform the perceiving function (for example, for the visual analyzer, these are the receptors of the retina);

2) the centripetal path from this sense organ to the cerebral hemispheres, providing a conductive function (for example, the optic nerves and pathways through the diencephalon);

3) the perceiving zone in the cerebral hemispheres, which implements the analyzing function (the visual zone in the occipital region of the cerebral hemispheres).

Receptor specificity. Receptors are specialized formations adapted to perceive certain influences of the external and internal environment. Receptors have specificity, that is, high excitability only to certain stimuli, which are called adequate. In particular, light waves are an adequate stimulus for the eye, and sound waves for the ear, etc. Under the action of adequate stimuli, sensations arise that are characteristic of a certain sense organ. So, eye irritation causes visual sensations, ear - auditory, etc. In addition to adequate, there are inadequate (inadequate) stimuli that cause only an insignificant part of the sensations inherent in this sense organ, or act in an unusual way. For example, mechanical or electrical irritation of the eye is perceived as a bright flash of light ("phosphene"), but does not give an image of the object and the perception of colors. The specificity of the sense organs is the result of the organism's adaptation to environmental conditions.

Each receptor has the following properties:

a) a certain value of the threshold of excitability, that is, the smallest stimulus force capable of causing sensation;

b) chronaxia;

c) time threshold - the smallest interval between two stimuli at which two sensations differ;

d) the threshold of discrimination - the smallest increase in the strength of the stimulus, causing a barely noticeable difference in sensation (for example, in order to distinguish the difference in the pressure of the load on the skin with closed eyes, you need to add about 3.2–5.3% of the initial load);

e) adaptation - a sharp drop (increase) in the strength of sensation immediately after the onset of the stimulus. Adaptation is based on a decrease in the frequency of excitation waves arising in the receptor when it is irritated.

The organs of taste. In the epithelium of the oral mucosa are taste buds that are round or oval in shape. They consist of oblong and flat cells located at the base of the bulb. Oblong cells are divided into supporting cells (located on the periphery) and taste cells (located in the center). Each taste bud has two to six taste cells, and their total number in an adult reaches 9 thousand. Taste buds are located in the papillae of the mucous membrane of the tongue. The apex of the taste bulb does not reach the surface of the epithelium, but communicates with the surface using the taste channel. Separate taste buds are located on the surface of the soft palate, the back of the pharynx, and the epiglottis. Centripetal impulses from each taste bulb are conducted along two or three nerve fibers. These fibers are part of the tympanic string and the lingual nerve, which innervate the anterior two-thirds of the tongue, and from the posterior third are part of the glossopharyngeal nerve. Further, through the visual hillocks, centripetal impulses enter the gustatory zone of the cerebral hemispheres.

The organs of smell. Smell receptors are located in the upper part of the nasal cavity. Olfactory cells are neurons surrounded by supporting cylindrical cells. A person has 60 million olfactory cells, the surface of each of them is covered with cilia, which increase the olfactory surface, which in humans is about 5 square meters. see From the olfactory cells, centripetal impulses along nerve fibers passing through the holes in the ethmoid bone enter the olfactory nerve, and then through the subcortical centers, where the second and third neurons are located, enter the olfactory zone of the cerebral hemispheres. Since the olfactory surface is located away from the respiratory tract, air with odorous substances penetrates to it only by diffusion.

Organs of skin sensitivity. Skin receptors are subdivided into tactile (their irritation causes sensations of touch), thermoreceptors (causes sensations of warmth and cold) and pain receptors.

Feelings of touch, or touch and pressure, are different in nature, for example, you cannot feel the pulse with your tongue. There are about 500 thousand tactile receptors in human skin. The threshold of excitability of tactile receptors in different parts of the body is not the same: the greatest excitability is in the receptors of the skin of the nose, fingertips and the mucous membrane of the lips, the lowest in the skin of the abdomen and groin. For tactile receptors, the simultaneous spatial threshold (the smallest distance between receptors at which simultaneous skin irritation causes two sensations) is the smallest; for pain receptors, it is the largest. The tactile receptors also have the smallest time threshold, that is, the time interval between two successive stimuli at which two separate sensations are evoked.

The total number of thermoreceptors is about 300 thousand, of which heat receptors - 250 thousand, cold receptors - 30 thousand. Cold receptors are located closer to the skin surface, heat receptors - deeper.

Pain receptors are numbered from 900 thousand to 1 million. Pain sensations excite defensive reflexes of skeletal muscles and internal organs, however, prolonged strong irritation of pain receptors causes disruption of many body functions. It is more difficult to localize painful sensations than other types of skin sensitivity, since the excitation that occurs when irritation of pain receptors is widely radiated through the nervous system. Simultaneous stimulation of the receptors for vision, hearing, smell and taste reduces the sensation of pain.

Vibration sensations (vibrations of objects with a frequency of 2-10 times per second) are well perceived by the skin of the fingers and the bones of the skull. Centripetal impulses from skin receptors travel along the dorsal roots to the spinal cord and reach the neurons of the dorsal horns. Then, along the nerve fibers that are part of the posterior columns (gentle and wedge-shaped bundles) and lateral (dorsal-thalamic bundles), the impulses reach the anterior nuclei of the visual hillocks. From here, the fibers of the third neuron begin, which, together with the fibers of proprioceptive sensitivity, reach the zone of skin-muscle sensitivity in the posterior central gyrus of the cerebral hemispheres.

5.2. Organs of vision. Eye structure

The eyeball consists of three membranes: outer, middle and inner. The outer, or fibrous, membrane is formed of dense connective tissue - the cornea (front) and the opaque sclera, or tunica albuginea (back). The middle (choroid) membrane contains blood vessels and consists of three sections:

1) the anterior section (iris, or iris). The iris contains smooth muscle fibers that make up two muscles: the circular, constricting the pupil, located almost in the center of the iris, and the radial, dilating the pupil. Closer to the front surface of the iris, there is a pigment that determines the color of the eye and the opacity of this shell. The iris is adjacent to the lens with its posterior surface;

2) the middle section (ciliary body). The ciliary body is located at the junction of the sclera into the cornea and has up to 70 ciliary radial processes. Inside the ciliary body is the ciliary, or ciliary, muscle, consisting of smooth muscle fibers. The ciliary muscle is attached by ciliary ligaments to the tendinous ring and the lens sac;

3) the posterior part (the choroid itself).

The inner membrane (retina) has the most complex structure. The main receptors in the retina are rods and cones. The human retina contains about 130 million rods and about 7 million cones. Each rod and cone has two segments - an external and an internal one; in a cone, the external segment is shorter. The outer segments of the rods contain visual purple, or rhodopsin (a purple substance), in the outer segments of the cones, iodopsin (purple). The inner segments of rods and cones are connected to neurons that have two processes (bipolar cells), which are in contact with ganglion neurons, which are part of the optic nerve with their fibers. Each optic nerve contains about 1 million nerve fibers.

The distribution of rods and cones in the retina has the following order: in the middle of the retina there is a central fovea (yellow spot) with a diameter of 1 mm, it contains only cones, cones and rods are located closer to the central fovea, and only rods are located on the periphery of the retina. In the central fossa, each cone through a bipolar cell is connected to one neuron, on the side of it, several cones are also connected to one neuron. Rods, unlike cones, are connected to one bipolar cell in several pieces (about 200). Thanks to this structure, the greatest visual acuity is provided in the central fossa. At a distance of approximately 4 mm medially from the central fossa is the optic papilla (blind spot), in the center of the nipple are the central artery and the central retinal vein.

Between the posterior surface of the cornea and the anterior surface of the iris and partly the lens is the anterior chamber of the eye. The posterior chamber of the eye is located between the posterior surface of the iris, the anterior surface of the ciliary ligament and the anterior surface of the lens. Both chambers are filled with transparent aqueous humor. The entire space between the lens and the retina is occupied by a transparent vitreous body.

Refraction in the eye. Refractive media of the eye include: cornea, aqueous humor of the anterior chamber of the eye, lens and vitreous humor. To a large extent, the clarity of vision depends on the transparency of these media, but the refractive power of the eye depends almost entirely on the refraction in the cornea and lens. Refraction is measured in diopters. Diopter is the reciprocal of focal length. The refractive force of the cornea is constant and equal to 43 diopters. The refractive power of the lens is unstable and varies over a wide range: when looking at a close distance - 33 diopters, into the distance - 19 diopters. The refractive power of the entire optical system of the eye: when looking into the distance - 58 diopters, at a short distance - 70 diopters.

Parallel light rays after refraction in the cornea and lens converge to one point in the fovea. The line passing through the centers of the cornea and lens to the center of the macula is called the visual axis.

Accommodation. The eye's ability to clearly distinguish objects at different distances is called accommodation. The phenomenon of accommodation is based on a reflex contraction or relaxation of the ciliary, or ciliary, muscle, innervated by the parasympathetic fibers of the oculomotor nerve. Contraction and relaxation of the ciliary muscle changes the curvature of the lens:

a) when the muscle contracts, the ciliary ligament relaxes, which causes an increase in light refraction, because the lens becomes more convex. Such a contraction of the ciliary muscle, or tension of vision, occurs when an object approaches the eye, that is, when examining an object that is as close as possible;

b) when the muscle relaxes, the ciliary ligaments stretch, the bag of the lens squeezes it, the curvature of the lens decreases and its refraction decreases. This happens when the object is farther from the eye, i.e. when looking into the distance.

The contraction of the ciliary muscle begins when the object approaches at a distance of about 65 m, then its contractions intensify and become distinct when the object approaches at a distance of 10 m.Further, as the object approaches, the muscles contract more and more and finally reach the limit at which clear vision becomes impossible. The minimum distance from an object to the eye at which it is clearly visible is called the closest point of clear vision. In a normal eye, the far point of clear vision is at infinity.

Farsightedness and myopia. A healthy eye, when looking into the distance, refracts a bundle of parallel rays so that they are focused in the fovea. With myopia, parallel rays are collected in focus in front of the central fovea, diverging rays fall into it and therefore the image of the object is blurred. Myopia can be caused by tension in the ciliary muscle when accommodating at a close distance or by a too long longitudinal axis of the eye.

In hyperopia (due to a short longitudinal axis), parallel rays are focused behind the retina, and converging rays fall into the central fossa, which also causes blurred images.

Both vision defects can be corrected. Myopia is corrected by biconcave lenses, which reduce refraction and shift focus to the retina; farsightedness - biconvex lenses that increase the refraction and therefore move the focus to the retina.

5.3. Light and color sensitivity. Light-receiving function

Under the action of light rays, a photochemical reaction of the splitting of rhodopsin and iodopsin occurs, and the reaction rate depends on the wavelength of the beam. Cleavage of rhodopsin in light gives a light sensation (colorless), iodopsin - color. Rhodopsin is cleaved much faster than iodopsin (about 1000 times), so the excitability of rods to light is greater than that of cones. This allows you to see at dusk and in low light.

Rhodopsin is composed of the protein opsin and oxidized vitamin A (retinen). Iodopsin also consists of a compound of retinene with the opsin protein, but with a different chemical composition. In the dark, with a sufficient intake of vitamin A, the restoration of rhodopsin and iodopsin is enhanced, therefore, with an excess of vitamin A (hypovitaminosis), a sharp deterioration in night vision occurs - hemeralopia. The difference in the rate of breakdown of rhodopsin and iodopsin leads to a difference in the signals entering the optic nerve.

As a result of the photochemical reaction, the excitation that has arisen from the ganglion cells is transmitted along the optic nerve to the external geniculate bodies, where the primary processing of the signal takes place. Then the impulses are transmitted to the visual zones of the cerebral hemispheres, where they are decoded into visual images.

Color perception. The human eye perceives light rays of various wavelengths from 390 to 760 nm: red - 620–760, orange - 585–620, yellow - 575–585, green-yellow - 550–575, green - 510–550, blue - 480– 510, blue - 450-480, purple - 390-450. Light rays with a wavelength of less than 390 nm and more than 760 nm are not perceived by the eye. The most widespread theory of color perception, the main provisions of which were first expressed by M.V. Lomonosov in 1756, and later developed by the English scientist Thomas Jung (1802) and G.L.F. Helmholtz (1866) and confirmed by the data of modern morphophysiological and electrophysiological studies, is as follows.

There are three types of cones, each of which contains only one color-reactive substance that has excitability to one of the primary colors (red, green or blue), as well as three groups of fibers, each of which conducts impulses from the same type of cones. The color stimulus affects all three types of cones, but to varying degrees. Different combinations of the degree of excitation of the cones create different color sensations. With equal stimulation of all three types of cones, a white sensation arises. This theory is called the three-component theory of color.

Features of coordination of vision in newborns. A child is born seeing, but he has not yet developed a clear, clear vision. In the first days after birth, eye movements in children are not coordinated. So, it can be observed that in a child the right and left eyes move in opposite directions, or when one eye is immobile, the other moves freely. In the same period, uncoordinated movements of the eyelids and the eyeball are observed (one eyelid can be open, and the other is lowered). The formation of coordination of vision occurs by the second month of life.

The lacrimal glands in the newborn are developed normally, but he cries without tears - there is no protective lacrimal reflex due to the underdevelopment of the corresponding nerve centers. Tears when crying in children appear after 1.2–2 months.

5.4. Light mode in educational institutions

As a rule, the educational process is closely associated with significant eye strain. A normal or slightly increased level of illumination of school premises (classrooms, offices, laboratories, training workshops, an assembly hall, etc.) helps to reduce the tension of the nervous system, maintain efficiency and maintain an active state of students.

Sunlight, in particular ultraviolet rays, promotes the growth and development of a child's body, reduces the risk of spreading infectious diseases, and ensures the formation of vitamin D in the body.

With insufficient illumination of classrooms, schoolchildren tilt their heads too low when reading, writing, etc. This causes an increased blood flow to the eyeball, exerting additional pressure on it, which leads to a change in its shape and contributes to the development of myopia. To avoid this, it is advisable to ensure the penetration of direct sunlight into the school premises and strictly observe the norms of artificial lighting.

Daylight. Illumination of the workplace of a student and teacher with direct or reflected rays of the sun depends on several parameters: on the location of the school building on the site (orientation), the interval between tall buildings, compliance with the coefficient of natural illumination, light coefficient.

The Ambient Light Ratio (KEO) is the percentage of indoor illumination (in lux) to illumination at the same outdoor level. This coefficient is considered the main indicator of the classroom illumination. It is determined using a light meter. The minimum allowable KEO for classrooms in areas of central Russia is 1.5%. In northern latitudes this coefficient is higher, in southern latitudes it is lower.

The light coefficient is the ratio of the area of \u200b\u200bglass in windows to the area of \u200b\u200bthe floor. In the classrooms and workshops of the school, it should be at least 1: 4, in the corridors and in the gym - 1: 5, 1: 6, respectively, in the auxiliary rooms - 1: 8, on staircases - 1: 12.

Illumination of classrooms with natural light depends on the shape and size of the windows, their height, as well as on the external environment of the building (neighboring houses, green spaces).

The rounding of the upper part of the window opening with one-sided lighting violates the ratio of the height of the window edge to the depth (width) of the room, which should be 1: 2, that is, the depth of the room should exceed double the height from the floor to the upper edge of the window. In practice, this means: the higher the upper edge of the window, the more direct sunlight enters the room and the better the lighting of the desks in the third row from the windows.

To prevent the glare of direct sunlight and overheating of the rooms, special visors are hung over the windows from the outside, and from the inside the room is shaded with light curtains. To prevent glare from reflected rays, it is not recommended to paint ceilings and walls with oil paints.

The color of the furniture also affects the illumination of school premises, so desks are painted in light colors or covered with light plastic. Dirty glass panes and flowers on the windowsills reduce the illumination. It is allowed to put flowers on the windowsills with a height (together with a flowerpot) no more than 25-30 cm. Tall flowers are placed at the windows on stands, and so that their crown does not protrude above the window sill above 25-30 cm, or in the walls on ladders or pots.

Artificial lighting. Incandescent lamps with a power of 250-350 W and fluorescent lamps of "white" light (type SB) with a power of 40 and 80 W are used as sources of artificial lighting in school premises. Luminescent lamps of diffused light are suspended in rooms where the ceiling height is 3.3 m; at a lower height, ceiling shades are used. All luminaires must be equipped with silent ballasts. The total power of fluorescent lamps in the classroom should be 1040 W, incandescent lamps - 2400 W, which is achieved by installing at least eight lamps of 130 W each with fluorescent lighting and eight 300 W lamps with incandescent lamps. Illumination rate (in watts) per 1 sq. m classroom area (the so-called specific power) with fluorescent lamps is 21-22, with incandescent lamps - 42-48. The first corresponds to an illumination of 300 lx, the second - 150 lx at a student's workplace.

Mixed lighting (natural and artificial) does not affect the visual organs. The same cannot be said about the simultaneous use of incandescent lamps and fluorescent lamps in the room, which have a different nature of the glow and the color of the luminous flux.

5.5. Auditory analyzer

The main function of the hearing organs is to perceive fluctuations in the air environment. The hearing organs are closely related to the organs of balance. The hearing and vestibular receptors are located in the inner ear.

Phylogenetically, they have a common origin. Both receptor apparatus are innervated by fibers of the third pair of cranial nerves, both react to physical indicators: the vestibular apparatus perceives angular acceleration, the auditory apparatus - air vibrations.

Auditory perception is very closely related to speech - a child who lost his hearing in early childhood loses speech ability, although his speech apparatus is absolutely normal.

In the embryo, hearing organs develop from the auditory vesicle, which initially communicates with the outer surface of the body, but as the embryo develops, it detaches from the skin and forms three semicircular canals located in three mutually perpendicular planes. The part of the primary auditory vesicle that connects these channels is called the vestibule. It consists of two chambers - oval (queen) and round (sac).

In the lower part of the vestibule, a hollow protrusion or tongue is formed from thin membranous chambers, which is stretched out in the embryos and then twisted in the form of a snail. The uvula forms the organ of Corti (the receiving part of the organ of hearing). This process occurs at the 12th week of intrauterine development, and at the 20th week, myelination of the fibers of the auditory nerve begins. In the last months of intrauterine development, differentiation of cells in the cortical part of the auditory analyzer begins, which proceeds especially intensively in the first two years of life. The formation of the auditory analyzer ends by the age of 12-13.

The organ of hearing. The human hearing organ consists of the outer ear, middle ear, and inner ear. The outer ear serves to catch sounds, it is formed by the auricle and the external auditory canal. The auricle is formed by elastic cartilage covered with skin on the outside. At the bottom, the auricle is supplemented with a skin fold - a lobe filled with adipose tissue. Determination of the direction of sound in humans is associated with binaural hearing, that is, hearing with two ears. Any lateral sound arrives in one ear before the other. The time difference (a few fractions of a millisecond) of the arrival of sound waves perceived by the left and right ears makes it possible to determine the direction of the sound. When one ear is affected, a person determines the direction of sound by rotating his head.

The external auditory canal in an adult has a length of 2.5 cm, a capacity of 1 cubic meter. see The skin lining the ear canal has fine hairs and modified sweat glands that produce earwax. They play a protective role. Earwax is made up of pigment-containing fat cells.

The outer and middle ear are separated by the tympanic membrane, which is a thin connective tissue plate. The thickness of the tympanic membrane is about 0.1 mm, from the outside it is covered with epithelium, and from the inside - with a mucous membrane. The eardrum is located obliquely and begins to vibrate when sound waves hit it. Since the eardrum does not have its own oscillation period, it oscillates at any sound according to its wavelength.

The middle ear is a tympanic cavity, which has the shape of a small flat drum with a tightly stretched vibrating membrane and auditory tube. In the middle ear cavity there are the auditory ossicles articulating with each other - the malleus, incus and stapes. The hammer handle is woven into the eardrum; the other end of the malleus is connected to the incus, and the latter is movably articulated with the stapes with the help of a joint. Attached to the stapes is the stapedius muscle, which holds it against the membrane of the oval window, which separates the inner ear from the middle ear. The function of the auditory ossicles is to provide an increase in the pressure of the sound wave during transmission from the tympanic membrane to the membrane of the oval window. This increase (approximately 30-40 times) helps the weak sound waves falling on the eardrum to overcome the resistance of the membrane of the oval window and transmit vibrations to the inner ear, transforming there into endolymph vibrations.

The tympanic cavity is connected to the nasopharynx by means of an auditory (Eustachian) tube 3.5 cm long, very narrow (2 mm), which maintains the same pressure from the outside and from the inside on the tympanic membrane, thereby providing the most favorable conditions for its oscillation. The opening of the tube in the pharynx is most often in a collapsed state, and air passes into the tympanic cavity during the act of swallowing and yawning.

The inner ear is located in the stony part of the temporal bone and is a bony labyrinth, inside which there is a membranous labyrinth of connective tissue, which is, as it were, inserted into the bony labyrinth and repeats its shape. Between the bony and membranous labyrinths there is a liquid - perilymph, and inside the membranous labyrinth - endolymph. In addition to the oval window, there is a round window in the wall separating the middle ear from the inner one, which allows fluid to oscillate.

The bony labyrinth consists of three parts: in the center is the vestibule, in front of it is the cochlea, and in the back there are semicircular canals. Bone cochlea is a spiraling canal forming two and a half turns around a conical rod. The diameter of the bony canal at the base of the cochlea is 0.04 mm, at the apex - 0.5 mm. A bony spiral plate departs from the rod, which divides the canal cavity into two parts - stairs.

Inside the middle canal of the cochlea is a spiral (Corti) organ. It has a basilar (main) plate, consisting of about 24 thousand thin fibrous filaments of various lengths. These filaments are very elastic and loosely connected to each other. On the main plate along it, supporting and hairy sensitive cells are located in five rows - these are the auditory receptors.

The inner hair cells are arranged in one row, along the entire length of the membranous canal, there are 3.5 thousand of them. The outer hair cells are arranged in three or four rows, there are 12-20 thousand of them. Each receptor cell has an elongated shape, it has 60-70 the smallest hairs (4–5 µm long). The hairs of the receptor cells are washed by the endolymph and come in contact with the integumentary plate, which hangs over them. Hair cells are enclosed by nerve fibers of the cochlear branch of the auditory nerve. The medulla oblongata contains the second neuron of the auditory pathway; then the path goes, crossing, to the posterior hillocks of the quadruple, and from them to the temporal region of the cortex, where the central part of the auditory analyzer is located.

There are several auditory centers in the cerebral cortex. Some of them (inferior temporal gyrus) are designed to perceive simpler sounds - tones and noises. Others are associated with the most complex sound sensations that arise at the time when a person speaks himself, listens to speech or music.

Sound perception mechanism. For the auditory analyzer, sound is an adequate stimulus. Sound waves arise as an alternation of thickening and rarefaction of air and propagate in all directions from the sound source. All vibrations of air, water or other elastic medium break down into periodic (tones) and non-periodic (noise).

There are high and low tones. Low tones correspond to fewer vibrations per second. Each sound tone is characterized by a sound wavelength, which corresponds to a certain number of vibrations per second: the greater the number of vibrations, the shorter the wavelength. High sounds have a short wavelength, measured in millimeters. The wavelength of low sounds is measured in meters.

The upper sound threshold in an adult is 20,000 Hz; the lowest is 12-24 Hz. Children have a higher upper limit of hearing - 22,000 Hz; in older people it is lower - about 15,000 Hz. The ear is most susceptible to sounds with a vibration frequency ranging from 1000 to 4000 Hz. Below 1000 Hz and above 4000 Hz, the excitability of the ear is greatly reduced.

In newborns, the middle ear cavity is filled with amniotic fluid. This makes it difficult for the ossicles to vibrate. Over time, the fluid dissolves, and instead of it, air enters from the nasopharynx through the Eustachian tube. A newborn baby shudders at loud sounds, his breathing changes, he stops crying. Hearing in children becomes clearer by the end of the second - beginning of the third month. After two months, the child differentiates qualitatively different sounds, at 3-4 months he distinguishes the pitch, at 4-5 months the sounds for him become conditioned reflex stimuli. By the age of 1–2, children distinguish sounds with a difference of one or two, and by the age of four or five, even 3/4 and 1/2 of the musical tone.

In the extensions of the semicircular canals (ampullae), there is one bony ridge, which has a sickle shape. Adjacent to the scallop is the membranous labyrinth and an accumulation of supporting and sensory receptors, which are provided with hairs. The semicircular canals are filled with endolymph.

The stimuli of the otolith apparatus are the accelerating or decelerating movement of the body, shaking, rolling and tilting the body or head to the side, causing pressure of the otoliths on the hairs of the receptor cells. An irritant of the receptors of the semicircular canals is an accelerated or slowed down rotational movement in any plane. The pulses coming from the otolith apparatus and semicircular canals make it possible to analyze the position of the head in space and changes in the speed and direction of movement. Increased irritation of the vestibular apparatus is accompanied by an increase or decrease in heart rate, respiration, vomiting, and increased sweating. With increased excitability of the vestibular apparatus in conditions of sea rolling, signs of "seasickness" occur, which are characterized by the above vegetative disorders. Similar changes are observed during flights, train travel and car travel.

The elementary rules of self-care are taught to a child from the cradle. Personal hygiene, includinghearing hygiene Is an important part of this training. In this case, the daily procedures aimed at maintaining the cleanliness of the ears are nothing more than the prevention of various infections entering them. Additional preventive measures include protecting the hearing organs from adverse external influences: hypothermia, industrial noise, other loud sounds, ingress of toxic substances, etc.

Let's consider the rules of hearing hygiene in more detail.

Basics of ear hygiene

You need to wash your ears, as well as wash your face, every day. This is the foundation of all hygiene rules for hearing organs. Strict adherence to it is a guarantee of the health of all parts of the ear and the most reliable prevention of various diseases.

With regard to cleaning the auricles with special cotton swabs, some caution must be exercised here. Incorrect actions can contribute to the formation of a dense, faithful plug, disrupt the natural process of earwax production, which protects the internal organs of hearing from the penetration of microbes and dust, and damage the eardrum.

But you shouldn't also refuse to clean your ears with cotton swabs. With excessive secretion of sulfur by the glands and its accumulation in the external auditory canal, a plug can form, which leads to hearing impairment. If such a problem appears, you cannot try to remove the sulfur plug from the ear on your own - you need to consult a doctor (ENT) who will quickly and painlessly eliminate the sulfur accumulated in the ear canal.

Do not allow water to enter your ears. This not only causes an unpleasant feeling of stuffiness and some hearing loss, but can also lead to severe pain. If water does get into the ear, it is necessary to lie on your back, and then slowly and slowly turn your head to the side so that the sore ear is below, and the water can flow out of it unhindered.

Prevention of hearing diseases

Prevention of ENT diseases and hearing hygiene largely depend on normal nasal breathing. With a runny nose, mucus accumulates in the inflamed sinuses, which can penetrate into the auditory tube. The result is an imbalance between external pressure and pressure in the middle ear. A feeling of congestion arises, due to which the person experiences noticeable discomfort.

But this is not the most dangerous thing. An infection that causes inflammation of the mucous membranes of the nasopharynx can spread to the internal parts of the hearing organs, provoking a serious illness. Therefore, it is impossible to blow your nose strongly with a runny nose, as well as to blow your nose simultaneously with both nostrils. It is correct to do this alternately, pressing first one and then the second wing of the nose to the septum and carefully freeing the nostrils from mucus.

Particular attention should be paid to the prevention of ENT diseases in case of infectious and viral diseases such as measles, flu, tonsillitis. Disease-causing bacteria - the causative agents of these diseases - can enter the middle ear through the auditory tube and cause severe inflammation.

Industrial noise can cause considerable harm to the health of the hearing organs. Constant loud sounds and noises can lead not only to a noticeable weakening of hearing or its complete loss, but also to cause rapid fatigue, impaired appetite and sleep, problems with the nervous system, and a deterioration in human performance. In addition, industrial noise can cause the development of a number of systemic diseases, such as hypertension, diseases of the gastrointestinal tract, etc.

To protect hearing organs from industrial noise, there are certain safety rules, including, among other things, the use of special sound-absorbing protective equipment - general and individual.

To prevent ear diseases, hearing impairment and basic organ protection from infections and viruses, it is very important to observe basic hygiene rules.

Earwax is released in the ear canal every day. With a large accumulation, it can block the external passage and affect the sensitivity of sounds.

It is known that ears have the ability to clean themselves from all sorts of blockages. Therefore, experts recommend cleaning the ears no more often than once a week.

The yellow substance that forms in the ear canal is called sulfur... It has the function of protecting against bacteria and viruses. Dead skin flakes and foreign bodies get into it.

In the process of self-cleaning of the body, it leaves the body during active movements of the lower jaw - while eating, talking or laughing.

Everyday and preventive hygiene of the organ of hearing is an important part of human life. Therefore, the prevention of ENT diseases should be carried out in time.

Hearing hygiene involves elimination of the influence of too strong noise on the ears... Loud and industrial noises cause serious harm the organ of hearing.

Constant finding in an enclosed and noisy environment causes partial or complete hearing loss... Also, noise causes severe fatigue and loss of performance, poor sleep and the onset of problems with the nervous system.

Therefore, if your work is associated with an increased level of noise, use protective equipment - ear plugs or sound-absorbing materials.

Ear hygiene

Exists hygiene rules and it is very important to adhere to them to maintain the overall health of the body.

To protect the ears, there are safety regulations and it's important to stick to them:

• Keep the ears clean;
• Do not stay for a long time in places with a high concentration of noise;
• For infectious and inflammatory diseases, contact your doctor;
• Try to exclude ear trauma;
• Treat colds in time.

Like face and body ears must be washed every day.

When doing this, make sure that no water gets into the ear canal. To do this, wash your ears at an angle.

Water ingress in the ear canal causes congestion, and can also provoke severe headache.

Do not forget clean not only the auricle itself, but also the space behind it. It is in this fold that bacteria can accumulate, which later cause infectious diseases.

The second cleaning method is specialized cotton swabs.

However, not all otolaryngologists allow this method of cleaning from contamination.

According to statistics, most of the injuries come precisely from cotton swabs. Therefore, exercise the utmost care when using them.

Incorrect actions can cause the formation of sulfur plugs and disrupt the natural process of earwax production, as well as move the already accumulated sulfur deeper, disrupting the natural physiology.

Additionally, you can damage your eardrum.

However, use cotton swabs necessary.

If you give up ear sticks forever, wax will accumulate in your ear, which will contribute to the formation of plugs. Closing the passages, a sulfur plug will provoke ear inflammation, for example.

Use specialized ear sticks with restraints. Then the cleaning will be safe.

Remember: if a large accumulation of sulfur plug appears, do not try to clean it yourself. With such a problem, you need to contact the ENT.

Complementary ear cleaning method

Exist one more method cleaning - hydrogen peroxide.

Place in a tablespoon 15 drops liquids. Soak a cotton ball in the product and insert into your ears. Take out the turunda through five minutes,and then dry thoroughly.

Please consult your healthcare professional before using this method.

If there is a lot of wax, wash your ears. However, this procedure should only be performed by a specialist using the device. Self-medication can harm your health.

Hygiene of ears in children

A baby's ears have the same self-cleaning function as an adult's. Sulfur moves outward during eating and under the sucking reflex.

A child's hearing hygiene begins with the removal of the visible wax in the outer ear.

Before you clean your child's ears, purchase special gauze swabs at the pharmacy or make your own from a cotton pad and bandage. Soak the resulting swab in hydrogen peroxide solution and wipe the outside area. Repeat the procedure once a week.

The correct shape of the turunda looks as shown in the photo.

Remove sulfur by 3% hydrogen peroxide only in the outer ear, without affecting other canals.

Make sure that when swimming in the bathtub or rivers and lakes in the warm season, water does not flow into the ear canal. Since it is in moisture that infectious diseases start.

Remember that children under one year old are prohibited from swimming in open water.

After bathing dry your ears thoroughly baby with a cotton pad.

Prevention

Hygiene of the ears is not only regular cleansing, but also the prevention of diseases of the ENT organs.

In case of inflammation of the ear cavity, nose and throat, it is important to cleanse the accumulated mucus. Since it can pass into the Eustachian tube and cause otitis media and. In addition, the infection can cause flu, measles, or sore throat.

Remember to wear a hat during the cooler season. Thus, you will exclude the possibility of ear frostbite and colds.

Adhere to the rules of hygiene of the organs of vision and hearing and then diseases will bypass you.

In order to prevent a decrease in hearing acuity and to protect the hearing organs from the harmful effects of the external environment, the penetration of viruses and the development of dangerous diseases, adhere to the basic rules of hygiene of the hearing organs and monitor the condition of your ears, cleanliness and condition of hearing, it is necessary constantly and necessarily.

Hearing hygiene means that the ears should be cleaned no more than twice a week if they are not heavily soiled. It is not necessary to get rid of the sulfur that is in the auditory canal too carefully: it protects the human body from the penetration of pathogens into it, removes debris (skin flakes, dust, dirt), moisturizes the skin.

Therefore, the hearing organs must be cleaned correctly so as not to injure the ears during cleaning, contributing to hearing impairment. This happens when trying to clean the ear canal with ear sticks or other sharp objects, the ear is damaged and scratches appear on the skin, through which viruses and bacteria can enter, causing inflammation.

Trying to get the sulfur from the ear canal, cotton swabs try to stick it as deep as possible, which is fraught with serious consequences. If there is a sulfur plug in the ear canal at this time, the cotton swab, instead of removing it, pushes it deeper, right next to the eardrum, which makes it difficult even for a doctor to remove the plug from the ear. If there is no plug, a cotton swab that is too deep can injure the eardrum and cause the membrane to rupture.

In order to prevent this, the auricle and ear canal must be cleaned while bathing or taking a shower by soaping a finger and running it along the outer edge and around the opening of the auditory canal, then gently rinse off the water so that no water gets into the ear and wipe dry.

For more serious cleaning, hygiene rules allow using hydrogen peroxide: dissolve 10-15 drops of the product in a tablespoon, moisten cotton wool in it, put it in the ear and leave for a few minutes. When the cotton wool is dry, you need to take it out and wipe your ear dry.

If your ears are blocked, your hearing has worsened, an excessive amount of sulfur has begun to stand out, you need to consult a doctor: this may indicate the presence of a sulfur plug (you should not get rid of it yourself: this should be done by a specialist) or a more serious disease, for example, the appearance of a fungus in the ears or ear inflammation. In this case, you cannot rinse your ears with water.

Water

Hygiene of the ears also means protecting them from water entering the auditory canal, the presence of which in the ear directly affects the ability to perceive sound signals. When water enters the auditory canal, there is a feeling of congestion, a hum in the head, and painful sensations may appear.

Despite the fact that water will not get into the middle ear with an intact eardrum, if it remains in the ear canal, it can cause inflammation of the outer ear or contribute to the development of fungus in the ears, which will not be easy to get rid of.

In order to prevent such consequences, before going to the pool, the auditory canal must be lubricated with petroleum jelly, swim in a cap. If the fluid managed to get into the ear canal, to get rid of it, you need to tilt your head so that the water flows out of it by itself. This can be done more effectively by lying on your back and slowly turning your head to the side of the affected ear.

You can also get rid of the water in the ear canal by taking a deep breath, then pinch your nose with your fingers, and exhale without opening your mouth. The pressure in the ear-nose-throat will push the water out of the ear.

Inflammatory diseases

Since the ear is very closely connected with the nose and throat, ear hygiene requires a healthy nasopharynx. Inflammation of the nasal mucosa or throat can lead to inflammation of the Eustachian tube, which connects the middle ear to the nasopharynx, as a result of which bacteria can freely enter the hearing organs through it, causing otitis media or another equally serious disease, which will lead to hearing impairment and severe pain.

So that the disease does not spread to the organs of hearing, in case of colds, it is very important to blow your nose correctly. Do this not with two nostrils, but alternately: first close one nostril and blow out mucus from the other, then do the opposite.

Noise

Hearing hygiene provides for the elimination of exposure to too much noise on the ears, which can lead not only to hearing impairment, but also to deafness. Loud sounds directly affect the elasticity of the eardrum, which, because of this, ceases to normally perceive and perform its functions.

If the work is associated with an increased noise level or the apartment is located near a highway or an airport, in order to protect your hearing from its effects, it is imperative to use protective equipment (earplugs, sound-absorbing materials).

It is also advisable to avoid listening to music with headphones, especially at maximum volume: this leads to neuritis (inflammation of the nerves), and progressive hearing loss. Ideally, do not use headphones at all, and if you do listen to music in them, then at minimum volume.

Earrings

The ear piercing procedure should be carried out only by a specialist doctor who knows exactly where to make a puncture so as not to harm the body: there are a lot of points associated with the internal organs inside the auricle, so a puncture in the wrong place can negatively affect their work. If this procedure is done incorrectly, the ears can start to fester, and the puncture will take a very long time to heal.

Frost

Many people do not want to wear hats during cold weather, at subzero temperatures. This can entail not only various diseases of the hearing organ, including frostbite, but also cause inflammation of the cerebral cortex (meningitis).

Prevention of hearing

To maintain hearing acuity for as long as possible and to hear as good as twenty at the age of fifty, ear hygiene should not be ignored. To do this, you need to remember and follow several rules. First of all, it is necessary to properly clean the ears, and avoid getting water into the hearing organs.

Colds, viral and other diseases must always be treated on time, in no case should they be started, and at the first signs of inflammation, consult a doctor: this is fraught with hearing impairment, which may not be able to fully recover in a chronic form.