How is the human ear. The best diagram of the structural features of the external, outer ear of a person with a photo and description

The ear has two main functions: the organ of hearing and the organ of balance. The organ of hearing is the main of the information systems that take part in the formation of the speech function, and therefore, the mental activity of a person. Distinguish between outer, middle and inner ear.

Outer ear - auricle, external auditory meatus

Middle ear - tympanic cavity, auditory tube, mastoid process

Inner ear (labyrinth) - cochlea, vestibule and semicircular canals.

The outer and middle ear provide sound conduction, and the receptors for both auditory and vestibular analyzers are located in the inner ear.

Outer ear. The auricle is a curved plate of elastic cartilage, covered on both sides with perichondrium and skin. The auricle is a funnel that provides optimal perception of sounds in a certain direction of sound signals. It also has significant cosmetic value. Such anomalies of the auricle are known as macro- and microotia, aplasia, protrusion, etc. Disfigurement of the auricle is possible with perichondritis (trauma, frostbite, etc.). Its lower part - the lobe - is devoid of a cartilaginous base and contains fatty tissue. In the auricle, a curl (helix), an antihelix (anthelix), a tragus (tragus), an antitragus (antitragus) are distinguished. The curl is part of the external auditory meatus. The external auditory meatus in an adult consists of two sections: the external one is membranous-cartilaginous, equipped with hairs, sebaceous glands and their modifications - earwax glands (1/3); internal - bone, not containing hair and glands (2/3).

Topographic and anatomical ratios of the parts of the ear canal are of clinical importance. front wall - borders on the articular bag of the lower jaw (important for external otitis media and injuries). Bottom - the parotid gland is adjacent to the cartilaginous part. The anterior and lower walls are pierced with vertical fissures (santorini fissures) in the amount of 2 to 4, through which suppuration can pass from the parotid gland to the auditory canal, as well as in the opposite direction. rear – borders on the mastoid process. In the depths of this wall is the descending part of the facial nerve (radical surgery). Upper – borders on the middle cranial fossa. Upper back – is the anterior wall of the antrum. Its omission indicates purulent inflammation of the cells of the mastoid process.

The outer ear is supplied with blood from the external carotid artery system due to the superficial temporal (a. temporalis superficialis), occipital (a. occipitalis), posterior auricular and deep ear arteries (a. auricularis posterior et profunda). Venous outflow is carried out in the superficial temporal (v. temporalis superficialis), external jugular (v. jugularis ext.) and maxillary (v. maxillaris) veins. Lymph is drained to the lymph nodes located on the mastoid process and anterior to the auricle. Innervation is carried out by branches of the trigeminal and vagus nerves, as well as from the ear nerve from the superior cervical plexus. Due to the vagal reflex with sulfur plugs, foreign bodies, cardialgic phenomena, cough are possible.

The boundary between the outer and middle ear is the tympanic membrane. The tympanic membrane (Fig. 1) is approximately 9 mm in diameter and 0.1 mm thick. The tympanic membrane serves as one of the walls of the middle ear, tilted forward and down. In an adult, it is oval in shape. B / p consists of three layers:

external - epidermal, is a continuation of the skin of the external auditory canal,

internal - mucous lining the tympanic cavity,

the fibrous layer itself, located between the mucous membrane and the epidermis and consisting of two layers of fibrous fibers - radial and circular.

The fibrous layer is poor in elastic fibers, so the tympanic membrane is not very elastic and can rupture with sharp pressure fluctuations or very strong sounds. Usually, after such injuries, a scar subsequently forms due to the regeneration of the skin and mucous membrane, the fibrous layer does not regenerate.

In b / p, two parts are distinguished: stretched (pars tensa) and loose (pars flaccida). The stretched part is inserted into the bony tympanic ring and has a middle fibrous layer. Loose or relaxed attached to a small notch of the lower edge of the scales of the temporal bone, this part does not have a fibrous layer.

On otoscopic examination, the color is b / n pearly or pearl gray with a slight sheen. For the convenience of clinical otoscopy, the b/p is mentally divided into four segments (antero-superior, anterior-inferior, posterior-superior, posterior-inferior) by two lines: one is a continuation of the malleus handle to the lower edge of the b/p, and the second passes perpendicular to the first through the navel b/p.

Middle ear. The tympanic cavity is a prismatic space in the thickness of the base of the pyramid of the temporal bone with a volume of 1-2 cm³. It is lined with a mucous membrane that covers all six walls and passes behind into the mucous membrane of the cells of the mastoid process, and in front into the mucous membrane of the auditory tube. It is represented by a single-layer squamous epithelium, with the exception of the mouth of the auditory tube and the bottom of the tympanic cavity, where it is covered with ciliated cylindrical epithelium, the movement of the cilia of which is directed towards the nasopharynx.

External (webbed) the wall of the tympanic cavity for a greater extent is formed by the inner surface of the b / n, and above it - by the upper wall of the bone part of the auditory canal.

Internal (labyrinth) the wall is also the outer wall of the inner ear. In its upper section there is a vestibule window, closed by the base of the stirrup. Above the window of the vestibule is a protrusion of the facial canal, below the window of the vestibule - a round-shaped elevation, called the cape (promontorium), corresponds to the protrusion of the first whorl of the cochlea. Below and behind the cape is a snail window, closed by a secondary b/p.

Upper (tire) the wall is a rather thin bony plate. This wall separates the middle cranial fossa from the tympanic cavity. Dehiscences are often found in this wall.

Inferior (jugular) wall - formed by the stony part of the temporal bone and is located 2-4.5 mm below the b / p. It borders on the bulb of the jugular vein. Often there are numerous small cells in the jugular wall that separate the bulb of the jugular vein from the tympanic cavity, sometimes dehiscences are observed in this wall, which facilitates the penetration of infection.

Anterior (sleepy) the wall in the upper half is occupied by the tympanic mouth of the auditory tube. Its lower part borders on the canal of the internal carotid artery. Above the auditory tube is a semi-channel of the muscle that strains the eardrum (m. tensoris tympani). The bone plate separating the internal carotid artery from the mucous membrane of the tympanic cavity is permeated with thin tubules and often has dehiscences.

Posterior (mastoid) the wall borders on the mastoid process. The entrance to the cave opens in the upper section of its back wall. In the depths of the posterior wall, the canal of the facial nerve passes, from this wall the stirrup muscle begins.

Clinically, the tympanic cavity is conditionally divided into three sections: the lower (hypotympanum), middle (mesotympanum), upper or attic (epitympanum).

The auditory ossicles involved in sound conduction are located in the tympanic cavity. The auditory ossicles - hammer, anvil, stirrup - are a closely connected chain that is located between the tympanic membrane and the vestibule window. And through the vestibule window, the auditory ossicles transmit sound waves to the fluid of the inner ear.

Hammer - it distinguishes the head, neck, short process and handle. The handle of the malleus is fused with the b/p, the short process protrudes outwards the upper section of the b/p, and the head articulates with the body of the anvil.

Anvil - it distinguishes the body and two legs: short and long. The short leg is placed at the entrance to the cave. The long leg is connected to the stirrup.

stirrup - it distinguishes head, anterior and posterior legs, interconnected by a plate (base). The base covers the window of the vestibule and is strengthened with the window with the help of an annular ligament, due to which the stirrup is movable. And this provides a constant transmission of sound waves to the fluid of the inner ear.

Muscles of the middle ear. The tensing muscle b / n (m. tensor tympani), is innervated by the trigeminal nerve. The stirrup muscle (m. stapedius) is innervated by a branch of the facial nerve (n. stapedius). The muscles of the middle ear are completely hidden in the bone canals, only their tendons pass into the tympanic cavity. They are antagonists, they contract reflexively, protecting the inner ear from excessive amplitude of sound vibrations. Sensitive innervation of the tympanic cavity is provided by the tympanic plexus.

The auditory or pharyngeal-tympanic tube connects the tympanic cavity with the nasopharynx. The auditory tube consists of bone and membranous-cartilaginous sections, opening into the tympanic cavity and nasopharynx, respectively. The tympanic opening of the auditory tube opens in the upper part of the anterior wall of the tympanic cavity. The pharyngeal opening is located on the side wall of the nasopharynx at the level of the posterior end of the inferior turbinate 1 cm posterior to it. The hole lies in a fossa bounded above and behind by a protrusion of tubal cartilage, behind which there is a depression - Rosenmuller's fossa. The mucous membrane of the tube is covered with multinucleated ciliated epithelium (the movement of cilia is directed from the tympanic cavity to the nasopharynx).

The mastoid process is a bone formation, according to the type of structure of which they distinguish: pneumatic, diploetic (consists of spongy tissue and small cells), sclerotic. The mastoid process through the entrance to the cave (aditus ad antrum) communicates with the upper part of the tympanic cavity - the epitympanum (attic). In the pneumatic type of structure, the following groups of cells are distinguished: threshold, perianthral, ​​angular, zygomatic, perisinus, perifacial, apical, perilabyrinthine, retrolabyrinthine. At the border of the posterior cranial fossa and mastoid cells, there is an S-shaped recess to accommodate the sigmoid sinus, which drains venous blood from the brain to the bulb of the jugular vein. Sometimes the sigmoid sinus is located close to the ear canal or superficially, in this case they speak of sinus presentation. This must be borne in mind during surgical intervention on the mastoid process.

The middle ear is supplied by branches of the external and internal carotid arteries. Venous blood drains into the pharyngeal plexus, bulb of the jugular vein, and middle cerebral vein. Lymphatic vessels carry lymph to the retropharyngeal lymph nodes and deep nodes. The innervation of the middle ear comes from the glossopharyngeal, facial and trigeminal nerves.

Due to the topographic and anatomical proximity facial nerve to the formations of the temporal bone, we trace its course. The trunk of the facial nerve is formed in the region of the cerebellopontine triangle and is sent along with the VIII cranial nerve to the internal auditory meatus. In the thickness of the stony part of the temporal bone, near the labyrinth, its stony ganglion is located. In this zone, a large stony nerve branches off from the trunk of the facial nerve, containing parasympathetic fibers for the lacrimal gland. Further, the main trunk of the facial nerve passes through the thickness of the bone and reaches the medial wall of the tympanic cavity, where it turns posteriorly at a right angle (the first knee). The bone (fallopian) nerve canal (canalis facialis) is located above the window of the vestibule, where the nerve trunk can be damaged during surgical interventions. At the level of the entrance to the cave, the nerve in its bone canal goes steeply down (second knee) and exits the temporal bone through the stylomastoid foramen (foramen stylomastoideum), splitting fan-shaped into separate branches, the so-called goose foot (pes anserinus), innervating the facial muscles. At the level of the second knee, the stirrup departs from the facial nerve, and caudally, almost at the exit of the main trunk from the stylomastoid foramen, there is a tympanic string. The latter passes in a separate tubule, penetrates the tympanic cavity, heading anteriorly between the long leg of the anvil and the handle of the malleus, and leaves the tympanic cavity through the stony-tympanic (glazer) fissure (fissura petrotympanical).

inner ear lies in the thickness of the pyramid of the temporal bone, two parts are distinguished in it: the bone and membranous labyrinth. In the bony labyrinth, the vestibule, cochlea, and three bony semicircular canals are distinguished. The bony labyrinth is filled with fluid - perilymph. The membranous labyrinth contains endolymph.

The vestibule is located between the tympanic cavity and the internal auditory canal and is represented by an oval-shaped cavity. The outer wall of the vestibule is the inner wall of the tympanic cavity. The inner wall of the vestibule forms the bottom of the internal auditory meatus. It has two recesses - spherical and elliptical, separated from each other by a vertically running crest of the vestibule (crista vestibule).

The bony semicircular canals are located in the posterior inferior part of the bony labyrinth in three mutually perpendicular planes. There are lateral, anterior and posterior semicircular canals. These are arcuate curved tubes in each of which two ends or bone legs are distinguished: expanded or ampullar and non-expanded or simple. The simple bony pedicles of the anterior and posterior semicircular canals join to form a common bony pedicle. The canals are also filled with perilymph.

The bony cochlea begins in the anteroinferior part of the vestibule with a canal, which spirally bends and forms 2.5 curls, as a result of which it was called the spiral canal of the cochlea. Distinguish between the base and the top of the cochlea. The spiral canal winds around a cone-shaped bone rod and ends blindly in the region of the top of the pyramid. The bone plate does not reach the opposite outer wall of the cochlea. The continuation of the spiral bone plate is the tympanic plate of the cochlear duct (basic membrane), which reaches the opposite wall of the bone canal. The width of the spiral bone plate gradually narrows towards the apex, and the width of the tympanic wall of the cochlear duct increases accordingly. Thus, the shortest fibers of the tympanic wall of the cochlear duct are at the base of the cochlea, and the longest at the apex.

The spiral bone plate and its continuation - the tympanic wall of the cochlear duct divide the cochlear canal into two floors: the upper one is the scala vestibuli and the lower one is the scala tympani. Both scalas contain perilymph and communicate with each other through an opening at the top of the cochlea (helicotrema). The scala vestibuli borders on the vestibule window, closed by the base of the stirrup, the scala tympani borders on the cochlear window, closed by the secondary tympanic membrane. The perilymph of the inner ear communicates with the subarachnoid space through the perilymphatic duct (cochlear aqueduct). In this regard, suppuration of the labyrinth can cause inflammation of the meninges.

The membranous labyrinth is suspended in the perilymph, filling the bony labyrinth. In the membranous labyrinth, two apparatuses are distinguished: vestibular and auditory.

The hearing aid is located in the membranous cochlea. The membranous labyrinth contains endolymph and is a closed system.

The membranous cochlea is a spirally wrapped canal - the cochlear duct, which, like the cochlea, makes 2½ turns. In cross section, the membranous cochlea has a triangular shape. It is located in the upper floor of the bony cochlea. The wall of the membranous cochlea, bordering the scala tympani, is a continuation of the spiral bone plate - the tympanic wall of the cochlear duct. The wall of the cochlear duct, bordering the scala vestibulum - the vestibular plate of the cochlear duct, also departs from the free edge of the bone plate at an angle of 45º. The outer wall of the cochlear duct is part of the outer bony wall of the cochlear canal. A vascular strip is located on the spiral ligament adjacent to this wall. The tympanic wall of the cochlear duct consists of radial fibers arranged in the form of strings. Their number reaches 15000 - 25000, their length at the base of the cochlea is 80 microns, at the top - 500 microns.

The spiral organ (Corti) is located on the tympanic wall of the cochlear duct and consists of highly differentiated hair cells supporting them with columnar and supporting Deiters cells.

The upper ends of the inner and outer rows of columnar cells are inclined towards each other, forming a tunnel. The outer hair cell is equipped with 100 - 120 hairs - stereocilia, which have a thin fibrillar structure. The plexuses of nerve fibers around the hair cells are guided through tunnels to the spiral knot at the base of the spiral bone plate. In total, there are up to 30,000 ganglion cells. The axons of these ganglion cells connect in the internal auditory canal to the cochlear nerve. Above the spiral organ is an integumentary membrane, which begins near the place of discharge of the vestibulum wall of the cochlear duct and covers the entire spiral organ in the form of a canopy. The stereocilia of hair cells penetrate the integumentary membrane, which plays a special role in the process of sound reception.

The internal auditory meatus begins with an internal auditory opening located on the posterior face of the pyramid and ends with the bottom of the internal auditory meatus. It contains the perdoor-cochlear nerve (VIII), consisting of the upper vestibular root and the lower cochlear. Above it is the facial nerve and next to it is the intermediate nerve.

This is the most complex and surprisingly accurate mechanism that allows you to perceive various sounds. Some people have a very delicate ear by nature, which is able to capture the most accurate intonations and sounds, while others, as they say, "a bear stepped on the ear." But How is the human ear? Here's what the researchers write.

outer ear

The human hearing aid can be divided into outer, middle and inner ear. The first part is everything that we see externally. The outer ear consists of the ear canal and the auricle. Internally, the auricle is designed so that a person begins to perceive various sounds. It consists of special cartilage, which is covered with skin. The lower part of the human ear has a small lobe, consisting of adipose tissue.

There is an opinion that it is in the area of ​​the outer ear and auricle that biologically active points are located, but this theory has not found an exact confirmation. It is for this reason that it is believed that only a competent specialist who knows the coordinates can pierce the ears. And this is another mystery - how the human ear works. After all, according to the Japanese theory, if you find biologically active points and massage or influence them with acupuncture, you can even treat some diseases.

The outer ear is the most vulnerable part of this organ. She is often injured, so she needs to be regularly monitored and protected from harmful influences. The auricle can be compared to the outer part of the speakers. It receives sounds, and their further transformation already takes place in the middle ear.

Middle ear

It consists of the tympanic membrane, malleus, anvil, and stirrup. The total area is about 1 cubic centimeter. You will not be able to see externally how the human middle ear is arranged without special instruments, since this area is located under the temporal bone. Separates the middle ear from the outer eardrum. Their function is to produce and transform sounds, as happens inside a loudspeaker. This area is connected to the nasopharynx by the Eustachian tube. If a person has a stuffy nose, then this invariably affects the perception of sounds. Many people notice that hearing during a cold deteriorates sharply. And the same thing happens if the region of the middle ear is inflamed, especially in diseases such as purulent otitis media. Therefore, it is important to protect your ears during frosts, as this can affect your hearing for life. Thanks to the Eustachian tube, the pressure in the ear normalizes. If the sound is very strong, then it may break. To prevent this from happening, experts advise opening your mouth during very loud sounds. Then the sound waves do not completely enter the ear, which partially reduces the risk of rupture. Only an otolaryngologist can see this area with the help of special devices.

inner ear

How is the human ear that lies deep within? It looks like a complex maze. This area consists of the temporal part and the bone. Outwardly, this mechanism resembles a snail. In this case, the temporal labyrinth is located inside the bone. The vestibular apparatus is located in this area, and it is filled with a special fluid - endolymph. The inner ear is associated with the transmission of sounds to the brain. This same organ allows you to maintain balance. Violations in the area of ​​the inner ear can lead to an inadequate response to loud sounds: a headache, nausea, and even vomiting begin. Various brain diseases, such as meningitis, also cause similar symptoms.

Hearing hygiene

In order for your hearing aid to serve you as long as possible, doctors advise you to follow these rules:

Keep your ears warm, especially when it's cold outside, and don't walk around in cold weather without a hat. Remember that in such a situation, the area of ​​\u200b\u200bthe ears may suffer the most;

Avoid loud and harsh sounds;

Do not try to clean your ears yourself with sharp objects;

In case of hearing impairment, headache with sharp sounds and discharge from the ears, you should consult an otolaryngologist.

By following these rules, you can save your hearing for a long time. However, even with the modern development of medicine, not everything is known about , how the human ear works. Scientists continue to research and constantly learn a lot about this hearing organ.

Ear - paired ( right and left), a symmetrical, complex organ of balance and hearing.

Anatomically, the ear is divided into three parts.
#one. outer ear It is represented by the external auditory canal, the length of which is 30 mm, as well as the auricle, which is based on elastic cartilage 1 mm thick. From above, the cartilage is covered with perichondrium and skin. The lower part of the shell is the lobe. It is devoid of cartilage and is formed by fatty tissue, which is also covered with skin. Almost every little girl is given a puncture by her parents ( in other words, piercing) lobes of each ear and decorate them with earrings. Ears should be pierced in compliance with the rules of asepsis in order to avoid local and general infection.

The free edge of the ear shell forms a curl. Parallel to the curl is the antihelix, anterior to which is the cavity of the ear shell. In the ear, a tragus and an antitragus are also distinguished. The auricle is attached to the mastoid and zygomatic process, as well as the temporal bone with the help of muscles and ligaments. The human ear is inactive due to the fact that the muscles that turn it are practically atrophied. The entrance to the outer ear is covered with hair and contains sebaceous glands. The shape of the auricles, like fingerprints, is individual for all people.

The ear canal connects the auricle and the eardrum. In adults, it is longer and narrower, while in children it is shorter and wider. That is why otitis media is more common in early childhood. The skin of the ear canal contains sulfur and sebaceous glands.

#2. Middle ear represented by the tympanic cavity, which is located in the temporal bone. It contains the smallest auditory ossicles in the human body: the hammer, stirrup and anvil. They transmit sound to the inner ear. The Eustachian tube connects the middle ear cavity with the nasopharynx;

#3. inner ear the most complex in its structure of all parts. It communicates with the middle ear through a round and oval window. Another name for the inner ear is the membranous labyrinth. It is immersed inside the bony labyrinth. It consists of:
the cochlea is the direct organ of hearing;
vestibule and semicircular tubules - responsible for acceleration, body position in space and balance.

Basic functions of the ear

Embryonic development of the ear

Ear diseases

#one. barotrauma- damage to the paranasal sinuses of the ear or the Eustachian tube associated with changes in ambient pressure. Causes: flying in an airplane, diving, etc. At the time of injury, there is severe pain, congestion and a feeling of a strong blow. Immediately there is a decrease in hearing, ringing and tinnitus. Rupture of the eardrum is accompanied by bleeding from the ear canal;

#2. congenital anomalies ears occur in the first 4 months of fetal development due to genetic defects. Anomalies of the ear are often combined with malformations of the face and skull. Frequent pathologies: absence of ears, macrotia - excessively large ears, microtia - very small ears. Pathologies of the development of the middle ear include: underdevelopment of the auditory ossicles, infection of the inner ear, etc.;

#3. The most common ear disease between 2 and 8 years of age is otitis media. This is due to the anatomical features of the ear. You can guess that the ear of a small child hurts if you press on the tragus. Usually the child starts to worry and cry. Characteristic signs of the disease: shooting pain, which can radiate to the head, and intensify when swallowing, sneezing. The cold makes you sick. As a rule, otitis is combined with rhinitis and tonsillitis;

#four. labyrinthitis- otitis media. Occurs due to incompletely treated otitis media. Sometimes the infection "rises" from caries-affected teeth by the hematogenous route. Symptoms of the disease: hearing loss, nystagmus ( involuntary movement of the eyeball) on the affected side, nausea, tinnitus, etc.

Diagnostics

Instrumental research methods:
X-ray of the temporal bone is of great importance for the diagnosis of various pathological formations of the middle and inner ear;
MRI provides more detailed information about the pathology of the ear; it is especially often used to diagnose tumor and inflammatory changes.

Treatment

How to eliminate sulfur plug? Sulfur is an important substance secreted by the glands of the outer ear. It performs a protective function, always standing out in the direction of the external auditory canal. As a rule, sulfur plugs occur in people who clean their ears too often or, conversely, very rarely. The most common symptom of cerumen is ear congestion. In addition, some people have itchy ears in the presence of sulfur plugs. You can try to remove the sulfur plug at home. To do this, you need to drip a warm solution of hydrogen peroxide into your ear. The sulfur plug will dissolve and hearing will be restored. In a polyclinic, the ear is washed with warm water using a Janet syringe.

Ear transplant

Prevention of ear diseases

The ear is a paired organ located deep in the temporal bone. The structure of the human ear allows you to receive mechanical vibrations of the air, transmit them through internal media, transform and transmit them to the brain.

The most important functions of the ear include the analysis of body position, coordination of movements.

In the anatomical structure of the human ear, three sections are conventionally distinguished:

• external;
• average;
• internal.

ear shell

It consists of cartilage up to 1 mm thick, over which there are layers of perichondrium and skin. The earlobe is devoid of cartilage, consists of adipose tissue covered with skin. The shell is concave, along the edge there is a roller - a curl.

Inside it is an antihelix, separated from the curl by an elongated recess - a rook. From the antihelix to the ear canal there is a recess called the cavity of the auricle. The tragus protrudes in front of the ear canal.

ear canal

Reflecting from the folds of the ear shell, the sound moves into the auditory 2.5 cm in length, with a diameter of 0.9 cm. The cartilage serves as the basis of the ear canal in the initial section. It resembles the shape of a gutter, open up. In the cartilaginous region, there are santorian fissures bordering the salivary gland.

The initial cartilaginous part of the ear canal passes into the bone part. The passage is bent in a horizontal direction, to inspect the ear, the shell is pulled back and up. In children - back and down.

The ear passage is lined with skin with sebaceous, sulfuric glands. Sulfur glands are modified sebaceous glands that produce. It is removed during chewing due to vibrations of the walls of the ear canal.

It ends with the tympanic membrane, blindly closing the ear canal, bordering:

• with the joint of the lower jaw, when chewing, the movement is transmitted to the cartilaginous part of the passage;
• with cells of the mastoid process, facial nerve;
• with salivary gland.

The membrane between the outer ear and the middle ear is an oval translucent fibrous plate, 10 mm long, 8-9 mm wide, 0.1 mm thick. The membrane area is about 60 mm 2 .

The plane of the membrane is inclined to the axis of the auditory canal at an angle, drawn funnel-shaped into the cavity. The maximum tension of the membrane is in the center. Behind the tympanic membrane is the cavity of the middle ear.

Distinguish:

• middle ear cavity (tympanic);
• auditory tube (Eustachian);
• auditory ossicles.

tympanic cavity

The cavity is located in the temporal bone, its volume is 1 cm 3. It houses the auditory ossicles, articulated with the eardrum.

Above the cavity is placed the mastoid process, consisting of air cells. It houses a cave - an air cell that serves as the most characteristic landmark in the anatomy of the human ear when performing any ear surgery.

auditory trumpet

The formation is 3.5 cm long, with a lumen diameter of up to 2 mm. Its upper mouth is located in the tympanic cavity, the lower pharyngeal mouth opens in the nasopharynx at the level of the hard palate.

The auditory tube consists of two sections, separated by its narrowest point - the isthmus. The bony part departs from the tympanic cavity, below the isthmus - membranous-cartilaginous.

The walls of the tube in the cartilaginous section are usually closed, slightly open when chewing, swallowing, yawning. The expansion of the lumen of the tube is provided by two muscles associated with the palatine curtain. The mucous membrane is lined with epithelium, the cilia of which move towards the pharyngeal mouth, providing the drainage function of the tube.

The smallest bones in the human anatomy - the auditory ossicles of the ear, are intended for conducting sound vibrations. In the middle ear there is a chain: hammer, stirrup, anvil.

The malleus is attached to the tympanic membrane, its head articulates with the incus. The process of the incus is connected to the stirrup attached by its base to the window of the vestibule located on the labyrinth wall between the middle and inner ear.

The structure is a labyrinth consisting of a bone capsule and a membranous formation that repeats the shape of the capsule.

In the bony labyrinth, there are:

• vestibule;
• snail;
• 3 semicircular canals.

Snail

The bone formation is a three-dimensional spiral of 2.5 turns around the bone rod. The width of the base of the cochlear cone is 9 mm, the height is 5 mm, and the length of the bone spiral is 32 mm. A spiral plate extends from the bone rod into the labyrinth, which divides the bone labyrinth into two channels.

At the base of the spiral lamina are the auditory neurons of the spiral ganglion. The bony labyrinth contains perilymph and a membranous labyrinth filled with endolymph. The membranous labyrinth is suspended in the bony labyrinth with the help of strands.

Perilymph and endolymph are functionally related.

• Perilymph - in ionic composition close to blood plasma;
• endolymph - similar to the intracellular fluid.

Violation of this balance leads to an increase in pressure in the labyrinth.

The cochlea is an organ in which the physical vibrations of the perilymph fluid are converted into electrical impulses from the nerve endings of the cranial centers, which are transmitted to the auditory nerve and to the brain. At the top of the cochlea is the auditory analyzer - the organ of Corti.

threshold

The most ancient anatomically the middle part of the inner ear is a cavity bordering the scala cochlea through a spherical sac and semicircular canals. On the wall of the vestibule leading to the tympanic cavity, there are two windows - oval, covered with a stirrup and round, which is a secondary tympanic membrane.

Features of the structure of the semicircular canals

All three mutually perpendicular bony semicircular canals have a similar structure: they consist of an expanded and simple pedicle. Inside the bone there are membranous canals that repeat their shape. The semicircular canals and sacs of the vestibule make up the vestibular apparatus, are responsible for balance, coordination, and determining the position of the body in space.

In a newborn, the organ is not formed; it differs from an adult in a number of structural features.

Auricle

• The shell is soft;
• the lobe and curl are poorly expressed, are formed by 4 years.

ear canal

• The bone part is not developed;
• the walls of the passage are located almost close;
• the tympanic membrane lies almost horizontally.

• Almost the size of adults;
• in children, the eardrum is thicker than in adults;
• covered with mucous membrane.

tympanic cavity

In the upper part of the cavity there is an open gap through which, in acute otitis media, the infection can penetrate the brain, causing meningism. In an adult, this gap is overgrown.

The mastoid process in children is not developed, it is a cavity (atrium). The development of the process begins at the age of 2 years, ends by 6 years.

auditory trumpet

In children, the auditory tube is wider, shorter than in adults, and is located horizontally.

A complex paired organ receives sound vibrations of 16 Hz - 20,000 Hz. Injuries, infectious diseases reduce the threshold of sensitivity, lead to a gradual loss of hearing. Advances in medicine in the treatment of ear diseases and hearing aids make it possible to restore hearing in the most difficult cases of hearing loss.

Video about the structure of the auditory analyzer

The human ear is a unique, rather complex organ in its structure. But, at the same time, the method of its work is very simple. The organ of hearing receives sound signals, amplifies them and converts them from ordinary mechanical vibrations into electrical nerve impulses. The anatomy of the ear is represented by many complex constituent elements, the study of which is singled out as a whole science.

Everyone knows that the ears are a paired organ located in the region of the temporal part of the human skull. But, a person cannot see the device of the ear in full, since the auditory canal is located quite deep. Only the auricles are visible. The human ear is capable of perceiving sound waves up to 20 meters long, or 20,000 mechanical vibrations per unit time.

The organ of hearing is responsible for the ability to hear in the human body. In order for this task to be performed in accordance with the original purpose, the following anatomical components exist:

human ear

• , presented in the form of an auricle and an auditory canal;
• , consisting of the tympanic membrane, a small cavity of the middle ear, the ossicular system, and the Eustachian tube;
• The inner ear, formed from a transducer of mechanical sounds and electrical nerve impulses - snails, as well as systems of labyrinths (regulators of balance and position of the human body in space).

Also, the anatomy of the ear is represented by the following structural elements of the auricle: curl, antihelix, tragus, antitragus, earlobe. Clinical is physiologically attached to the temple with special muscles called vestigial.

Such a structure of the hearing organ has the influence of external negative factors, as well as the formation of hematomas, inflammatory processes, etc. Ear pathologies include congenital diseases that are characterized by underdevelopment of the auricle (microtia).

outer ear

The clinical form of the ear consists of the outer and middle sections, as well as the inner part. All these anatomical components of the ear are aimed at performing vital functions.

The human outer ear is made up of the auricle and the external auditory meatus. The auricle is presented in the form of elastic dense cartilage, covered with skin on top. Below you can see the earlobe - a single fold of skin and adipose tissue. The clinical form of the auricle is rather unstable and extremely sensitive to any mechanical damage. Not surprisingly, professional athletes have an acute form of ear deformity.

The auricle serves as a kind of receiver for mechanical sound waves and frequencies that surround a person everywhere. It is she who is a repeater of signals from the outside world to the ear canal. If in animals the auricle is very mobile and plays the role of a barometer of dangers, then in humans everything is different.

The ear shell is lined with folds that are designed to receive and process distortion of sound frequencies. This is necessary so that the head part of the brain can perceive the information necessary for orientation in the area. The auricle acts as a kind of navigator. Also, this anatomical element of the ear has the function of creating surround stereo sound in the ear canal.

The auricle is capable of picking up sounds that propagate at a distance of 20 meters from a person. This is due to the fact that it is directly connected to the ear canal. Next, the cartilage of the passage is converted into bone tissue.


In the ear canal, there are sulfur glands that are responsible for the production of earwax, which is necessary in order to avoid the influence of pathogenic microorganisms. Sound waves that are perceived by the auricle penetrate the ear canal and hit the eardrum.

To avoid rupture of the eardrum during flights, explosions, high noise levels, etc., doctors recommend opening your mouth to push the sound wave away from the eardrum.

All vibrations of noise and sound come from the auricle to the middle ear.

The structure of the middle ear

The clinical form of the middle ear is presented as a tympanic cavity. This vacuum space is localized near the temporal bone. It is here that the auditory ossicles are located, referred to as the hammer, anvil, stirrup. All these anatomical elements are aimed at converting noise in the direction of their outer ear into the inner.

The structure of the middle ear

If we consider in detail the structure of the auditory ossicles, we can see that they are visually represented as a series-connected chain that transmits sound vibrations. The clinical handle of the malleus of the sense organ is closely attached to the tympanic membrane. Further, the head of the malleus is attached to the anvil, and that to the stirrup. Violation of the work of any physiological element leads to a functional disorder of the organ of hearing.

The middle ear is anatomically connected to the upper respiratory tract, namely the nasopharynx. The connecting link here is the Eustachian tube, which regulates the pressure of the air supplied from outside. If the surrounding pressure rises or falls sharply, then the person's ears are naturally blocked. This is the logical explanation for the painful sensations of a person that occur when the weather changes.

A severe headache, bordering on a migraine, suggests that the ears at this time are actively protecting the brain from damage.

A change in external pressure reflexively causes a reaction in the form of a yawn in a person. To get rid of it, doctors advise swallowing saliva several times or blowing sharply into a pinched nose.

The inner ear is the most complex in its structure, therefore in otolaryngology it is called a labyrinth. This organ of the human ear consists of the vestibule of the labyrinth, the cochlea, and the semicircular canaliculi. Further, the division goes according to the anatomical forms of the labyrinth of the inner ear.

inner ear model

The vestibule or membranous labyrinth consists of the cochlea, uterus and sac, connected to the endolymphatic duct. There is also a clinical form of receptor fields. Next, you can consider the structure of such organs as the semicircular canals (lateral, posterior and anterior). Anatomically, each of these canals has a stalk and an ampullar end.

The inner ear is represented as a cochlea, the structural elements of which are the scala vestibuli, the cochlear duct, the scala tympani, and the organ of Corti. It is in the spiral or Corti organ that the pillar cells are localized.

Physiological features

The organ of hearing has two main purposes in the body, namely the maintenance and formation of body balance, as well as the acceptance and transformation of environmental noises and vibrations into sound forms.

In order for a person to be in balance both at rest and during movement, the vestibular apparatus functions 24 hours a day. But, not everyone knows that the clinical form of the inner ear is responsible for the ability to walk on two limbs, following a straight line. This mechanism is based on the principle of communicating vessels, which are presented in the form of hearing organs.

The ear contains semicircular canals that maintain fluid pressure in the body. If a person changes the position of the body (state of rest, movement), then the clinical structure of the ear "adjusts" to these physiological conditions, regulating intracranial pressure.

The presence of the body at rest is ensured by such organs of the inner ear as the uterus and sac. Due to the constantly moving fluid in them, nerve impulses are transmitted to the brain.

Clinical support for body reflexes is also provided by muscle impulses delivered by the middle ear. Another complex of organs of the ear is responsible for focusing attention on a specific object, that is, it takes part in the performance of the visual function.

Based on this, we can say that the ear is an indispensable priceless organ of the human body. Therefore, it is so important to monitor his condition and contact specialists in time if there are any hearing pathologies.