Jugular vein and eustachian tube. Middle ear, auris media

The middle ear (auris media) consists of several interconnected air cavities: the tympanic cavity (cavum tympani), the auditory tube (tuba auditiva), the entrance to the cave (aditus ad antrum), the cave (antrum) and the air cells of the mastoid process associated with it (cellulae mastoidea). Through the auditory tube, the middle ear communicates with the nasopharynx; under normal conditions, this is the only communication of all middle ear cavities with the external environment.

Figure: 4.4.

1 - horizontal semicircular canal; 2 - canal of the facial nerve; 3 - roof of the tympanic cavity; 4 - window of the vestibule; 5 - muscle half-channel; 6 - tympanic opening of the auditory tube; 7 - canal of the carotid artery; 8 - promontorium; 9 - tympanic nerve; 10 - jugular fossa; 11 - snail window; 12 - drum string; 13 - pyramidal process; 14 - cave entrance.

Rough flat (Fig.4.4). The tympanic cavity can be compared to an irregular cube with a volume of up to 1 cm3. There are six walls in it: top, bottom, front, back, outer and inner.

The upper wall, or roof, of the tympanic cavity (tegmen tympani) is represented by a bone plate 1-6 mm thick. It separates the tympanic cavity from the middle cranial fossa. In the roof there are small holes through which the vessels pass, carrying blood from the dura mater to the mucous membrane of the middle ear. Sometimes dehiscences form in the upper wall; in these cases, the mucous membrane of the tympanic cavity is directly adjacent to the dura mater.

In newborns and children of the first years of life, an unstained gap (fissura petrosquamosa) is located on the border between the pyramid and the scales of the temporal bone, which causes the onset of cerebral symptoms in them with acute inflammation of the middle ear. Subsequently, a suture (sutura petrosquamosa) is formed at this place and the communication with the cranial cavity in this place is eliminated.

The lower (ankle) wall, or the bottom of the tympanic cavity (paries jugularis), borders on the underlying jugular fossa (fossa jugularis), in which the jugular vein bulb (bulbus venae jugularis). The more the fossa protrudes into the tympanic cavity, the thinner the bony wall. The inferior wall can be very thin or have dehiscence, through which the vein bulb sometimes protrudes into the tympanic cavity. This causes the possibility of injury to the bulb of the jugular vein, accompanied by severe bleeding, with paracentesis or careless scraping of granulations from the bottom of the tympanic cavity.

The anterior wall, tubal or carotid (paries tubaria, s.caroticus), the tympanic cavity is formed by a thin bone plate, outside of which the internal carotid artery is located. There are two openings in the front wall, the upper one, narrow, leads to the half-channel for the muscle stretching the eardrum (semicanalis m.tensoris tympani), and the lower, wide one, to the tympanic opening of the auditory tube (ostium tympanicum tybae auditivae). In addition, the anterior wall is pierced with thin tubules (canaliculi caroticotympanici), through which vessels and nerves pass into the tympanic cavity, in some cases it has dehiscence.

The posterior (centered) wall of the tympanic cavity (paries mastoideus) borders on the mastoid process. In the upper part of this wall there is a wide passage (aditus adantrum), which communicates the groove of the drumbeats - the attic (attic) with a permanent cell of the mastoid process - a cave (antrum mastoideum). Below this passage is the bony protrusion - the pyramidal process, from which the stapes muscle (m.stapedius) begins. On the outer surface of the pyramidal process is the tympanic opening (apertura tympanica canaliculi chordae), through which the drum string (chorda tympani), extending from the facial nerve, enters the tympanic cavity. The descending knee of the canal of the facial nerve passes through the thickness of the lower part of the posterior wall.

Outside (first) wall of the tympanic cavity (paries membranaceus) is formed by the tympanic membrane and partly in the area of \u200b\u200bthe attic with a bone plate that departs from the upper bone walls of the external auditory canal.

Internal I (lab and rint n and I, medial n and I, p about mon t about r and al n and I ) the wall of the tympanic cavity (paries labyrinthicus) is the outer wall of the labyrinth and separates it from the middle ear cavity. In the middle part of this wall there is an oval elevation - a promontorium, formed by the protrusion of the main curl of the snail.

Behind and up from the cape there is a niche of the vestibule window (oval window according to the old nomenclature; fenestra vestibuli), closed by the base of the stirrup (basis stapedis). The latter is attached to the edges of the window by means of an annular ligament (lig. Annulare). In the direction posteriorly and downwardly from the cape there is another niche, at the bottom of which there is a snail window (round window according to the old nomenclature; fenestra cochleae) leading into the cochlea and closed by a secondary tympanic membrane (membrana ympany secundaria), which consists of three layers: outer - mucous, middle - connective tissue and internal - endothelial.

Above the window of the vestibule along the inner wall of the tympanic cavity in the direction from front to back, there is a horizontal knee of the bony canal of the facial nerve, which, reaching the protrusion of the horizontal semicircular canal on the inner wall of the antrum, turns vertically downward-descending knee - and goes to the base of the skull through the styloid opening (for. stylomastoideum). The facial nerve is located in the bone canal (canalis Fallopii). A horizontal segment of the canal of the facial nerve above the window of the vestibule protrudes into the tympanic cavity in the form of a bone roller (prominentia canalis facialis). Here it has a very thin wall, in which dehiscences often occur, which contributes to the spread of inflammation from the middle ear to the nerve and the occurrence of paralysis of the facial nerve. An otolaryngologist sometimes has to deal with various variants and anomalies of the location of the facial nerve in both its tympanic and mastoid regions.

In the middle floor of the tympanic cavity, a drum string (chorda tympani) departs from the facial nerve. It passes between the malleus and the incus through the entire tympanic cavity near the tympanic membrane and exits it through the stony-tympanic (glazer) fissure (fissura petrotympanica, s.Glaseri), giving taste fibers to the tongue on its side, secretory fibers to the salivary gland and fibers to the nerve vascular plexuses.

The tympanic cavity is conventionally divided into three sections, or floors: the upper one is the attic, or epitympanum, located above the upper edge of the stretched part of the tympanic membrane, the height of the attic ranges from 3 to 6 mm. The articulation of the malleus with the incus enclosed in it divides the attic into the outer and inner sections. The lower part of the outer part of the attic is called the "upper recess of the tympanic membrane", or "Prussian space", posteriorly the attic passes into the antrum; medium - the largest in size (mesotympanum), corresponds to the location of the stretched part of the tympanic membrane; lower (hypotympanum) - a depression below the level of the tympanic membrane attachment (Fig. 4.5, a, b).

A - sagittal incision: 1 - superior ligament of the incus; 2 - short stem of the anvil; 3 - cave; 4 - the posterior ligament of the incus; 5 - long leg of the anvil; 6 - posterior hammer fold; 7 - back pocket of the membrane; 8 - lenticular process of the incus; 9 - hammer handle; 10 - canal of the facial nerve; 11 - drum string; 12 - facial nerve; 13 - drum ring; 14 - the stretched part of the tympanic membrane; 15- auditory tube; 16 - front hammer fold, 17 - front pocket of the membrane; 18 - ; 19 - hammer head; 20 - the upper ligament of the hammer; 21 - anvil-hammer joint.

The mucous membrane of the tympanic cavity is a continuation of the mucous membrane of the nasopharynx (through the auditory tube); it covers the walls of the tympanic cavity, the ossicles and their ligaments, forming a series of folds and pockets. Tightly adhering to the bone walls, the mucous membrane is for them at the same time the periosteum (mucoperiostom). It is covered mainly by squamous epithelium, with the exception of the mouth of the auditory tube,

Figure: 4.5. Continuation.

: 22 - anterior semicircular canal; 23 - posterior semicircular canal; 24 - lateral semicircular canal; 25 - stapes tendon; 26 - VIII cranial (vestibular cochlear) nerve; 27 - probe in the snail window; 28 - snail; 29 - muscle straining the eardrum; 30 - sleepy canal; 31 - stirrup; 32 - anterior process of the malleus; 33 - upper pocket of the tympanic membrane (space of Prussians); 34 - lateral ligament of the hammer.

Where there is ciliated columnar epithelium. In some places of the mucous membrane, glands are found.

The ear point - the malleus (malleus), the incus (incus) and the stapes (stapes) - are connected by articulations, anatomically and functionally represent a single chain (Fig. 4.6), which stretches from the eardrum to the window of the vestibule. The handle of the malleus is woven into the fibrous layer of the tympanic membrane, the base of the stirrup is fixed in the niche of the window of the vestibule. The main mass of the auditory ossicles - the head and neck of the malleus, the body of the incus - is located in the eardrum space (see Fig. 4.5, b). The auditory bones are reinforced with each other and with the walls of the tympanic cavity with the help of elastic ligaments, which ensures their free displacement when the tympanic membrane vibrates.

1 - anvil; 2 - long leg of the anvil; 3 - anvil joint; 4 - stirrup; 5 - back leg of the stirrup; 6 - the base of the stirrup; 7- front leg of the stirrup; 8 - hammer handle; 9 - anterior process of the malleus; 10 - hammer; 11 - hammer head; 12 - anvil-hammer joint; 13 - short process of the incus; 14 - the body of the anvil.

In the hammer, a handle, a neck and a head are distinguished. At the base of the handle there is a short process protruding outwardly part of the tympanic membrane. The mass of the hammer is about 30 mg.

The incus consists of a body, a short process and a long process articulated with a stirrup. The mass of the incus is about 27 mg.

In the stirrup, a head, two legs and a base are distinguished.

The annular ligament, with which the base of the stapes is attached to the edge of the window of the vestibule, is sufficiently elastic and provides good vibrational mobility of the stapes. In the anterior section, this ligament is wider than in the posterior one, therefore, during the transmission of sound vibrations, the base of the stapes is displaced mainly by its anterior pole.

The stirrup is the smallest of the auditory ossicles; its mass is about 2.5 mg with a base area of \u200b\u200b3-3.5 mm2.

The muscular paradimensional area is represented by two muscles: stretching the tympanic membrane (m.tensor tympani) and the stirrup (m. stapedius). Both of these muscles, on the one hand, hold the auditory ossicles in a certain position that is most favorable for conducting sound, on the other hand, they protect the inner ear from excessive sound stimuli by reflex contraction. The muscle that stretches the eardrum is attached at one end in the area of \u200b\u200bthe auditory tube opening, with the other to the handle of the hammer near the neck. It is innervated by the mandibular branch of the trigeminal nerve through the ear ganglion; the stapes muscle starts from the pyramidal protrusion and is attached to the stapes neck; innervated by the stapes nerve (n.stapedius) by a branch of the facial nerve.

The ear (e in a) tube, as already noted, is a formation through which the tympanic cavity communicates with the external environment: it opens in the nasopharynx. The auditory tube consists of two parts: a short bone tube - 1L canal (pars ossea) and a long cartilaginous tube - 2/3 (pars cartilaginea). Its length in adults is on average 3.5 cm, in newborns - 2 cm.

In the place of transition of the cartilaginous part into the bone, an isthmus (isthmus) is formed - the narrowest place (diameter 1-1.5 mm); it is located approximately 24 mm from the pharyngeal opening of the tube. The lumen of the bony part of the auditory tube in the section is a kind of triangle, and in the membranous section the walls of the tube are adjacent to each other.

The internal carotid artery passes medially to the bony part of the tube. It should be borne in mind that in the membranous cartilaginous part, the lower and anterior walls of the tube are represented only by fibrous tissue. The pharyngeal opening of the auditory tube is 2 times wider than the tympanic opening and is located 1-2.5 cm below it on the lateral wall of the nasopharynx at the level of the posterior end of the inferior turbinate.

Reduction of the tympanic cavity is carried out from the basins of the external and partially internal carotid arteries: the anterior, tympanic artery, extending from the maxillary; posterior ear artery, extending from the styloid artery and anastomosing with the middle meningeal artery. Branches branch off from the internal carotid artery to the anterior sections of the tympanic cavity.

Venous outflow from the tympanic cavity occurs mainly through the veins of the same name.

Limp from the tympanic cavity follows along the mucous membrane of the auditory tube into the pharyngeal lymph nodes.

Inneration of the tympanic cavity occurs due to the tympanic nerve (n.tympanicus) from the IX pair (n.glossopharyngeus) of the cranial nerves. Having entered the tympanic cavity, the tympanic nerve and its branches anastomose on the inner wall with branches of the facial nerve, trigeminal and sympathetic plexuses of the internal carotid artery, forming the tympanic plexus (plexus tympanicus s.Jacobsoni) on the cape.

Compound (prosessus mastoideus).

In a newborn, the mastoid part of the middle ear looks like a small elevation behind the upper-posterior edge of the tympanic ring, containing only one cavity - the antrum (cave). Starting from the 2nd year, this elevation is extended downward due to the development of the muscles of the neck and occiput. The formation of the shoot ends mainly by the end of the 6th - beginning of the 7th year of life.

The mastoid process of an adult resembles a cone, tilted downward by its tip - a protrusion. The internal structure of the mastoid process is not the same and depends mainly on the formation of air cavities. This process takes place by replacing bone marrow tissue with ingrowing epithelium. As the bone grows, the number of air cells increases. By the nature of pneumatization, one should distinguish: 1) pnevmatic type of structure of the mastoid process, when the number of air cells is large enough. They fill almost the entire process and sometimes even spread to the scales of the temporal bone, the pyramid, the bony part of the auditory tube, the zygomatic process; 2) d and ploethical (spongy, spongy) type of structure. In this case, the number of air cells is small, they look like small cavities bounded by trabeculae, and are located mainly near the cave; 3) sclerotic (compact) type of structure: the mastoid process is formed by extremely dense bone tissue.

If the pneumatic type of the structure of the mastoid process is observed during the normal development of the child, then diploetic and sclerotic are sometimes the result of metabolic disorders or the result of general and local inflammatory diseases, etc. There is an opinion that the process of pneumatization of the mastoid process is influenced to a certain extent by some genetic or constitutional factors, as well as the associated resistance and organ-tissue reactivity.

The anatomical structure of the mastoid process is such that all of its air cells, regardless of their distribution and location, communicate with each other and with the cave, which, through aditus ad antrum, communicates with the eardrum space of the tympanic cavity. The cave is the only congenital air cavity, its development does not depend on the type of structure of the mastoid process.

In infants, in contrast to adults, it is much larger in volume and is located quite close to the outer surface. In adults, the cave lies at a depth of 2-2.5 cm from the outer surface of the mastoid process. The size of the mastoid process in adults ranges from 9-15 mm in length, 5-8 mm in width and 4-18 mm in height. The size of the cave is the same for a newborn. A bony plate (tegmen antri) separates the cave from the dura mater of the middle cranial fossa, when destroyed by a purulent process, inflammation can go to the meninges.

The dura mater of the posterior cranial fossa is separated from the mastoid cavity by the Trautmann triangle, which is located posteriorly from the facial nerve to the sigmoid sinus. The mucous membrane lining the cave and air cells is a continuation of the mucous membrane of the tympanic cavity.

On the inner posterior surface (from the side of the cranial cavity) of the mastoid process, there is a groove-shaped depression. In it lies the sigmoid venous sinus (sinus sigmoideus), through which the outflow of venous blood from the brain to the jugular vein system is carried out. The dura mater of the posterior cranial fossa is delimited from the cellular system of the mastoid process by means of a thin but rather dense bone plate (lamina vitrea). In some cases, purulent inflammation of cells can lead to the destruction of this plate and the penetration of infection into the venous sinus. Occasionally, an injury to the mastoid can cause the sinus wall to break down and lead to life-threatening bleeding. The mastoid part of the facial nerve is located near the cells of the mastoid process. This neighborhood sometimes explains paralysis and paresis of the facial nerve in acute and chronic inflammation of the middle ear.

Outside, the mastoid process has a compact osteocortical layer, the surface of which is rough, especially in the lower section, where the sternocleidomastoid muscle (m.sternocleidomastoideus) is attached. On the inner side of the apex of the appendix there is a deep groove (incisura mastoidea), where the digastric muscle (m.digastricus) is attached. Through this groove, pus sometimes breaks out of the cells of the appendix under the cervical muscles. Within the outer surface of the mastoid process, there is a smooth triangular area called the "Shipot triangle". In the anteroposterior corner of this triangle there is a fossa in the form of a platform (planum mastoidea) and a scallop (spina suprameatum), which correspond to the outer wall of the antrum. In this area, bone trepanation is performed in search of a cave with mastoiditis in adults and antritis in children.

Borealisation of the mastoid region is carried out from the posterior ear artery (a.auricularis posterior - a branch of the external carotid artery - a.carotis externa). Venous outflow occurs in the vein of the same name, which flows into the external jugular vein (v. Jugularis externa).

Innervations of the mastoid region are provided by sensory nerves from the upper cervical plexus of the large ear (n.auricularis magnus) and the small occipital (n.oscipitalis minor). The motor nerve for the rudimentary posterior muscle (m.auricularis posterior) is the branch of the facial nerve of the same name.

The ear has three parts:

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• Outer ear
• Middle ear
• Inner ear

Outer ear

The outer ear consists of the auricle and the external auditory canal. The auricle is a complex shaped cartilage. The cartilaginous part becomes the bone part.

The cartilage canal contains hair follicles and glands that secrete earwax. Hair follicles are present only in the outer part of the ear canal; they are absent in the deeper parts of the outer ear canal. The ear canal changes shape and size with age.

Topography of the external auditory canal

Above the ear canal is the middle cranial fossa, behind the ear is the mastoid process; below the joint of the lower jaw and parotid glands.

Middle ear

The middle ear contains:

• Eardrum
• Eustachian tube
• Mastoid cells

Eardrum

The tympanic membrane consists of three layers: the outer epidermis, the middle - yellow elastic fibrous fibers and the inner mucous membrane.

Two parts are distinguished in the eardrum: stretched ( pars tensa) and loose ( pars flaccida). In pars flaccida, the fibrous layer is absent. This area is only the smaller top of the eardrum and is not easily seen. It is often referred to as the drum space; chronic perforation of this area is potentially dangerous, which will be discussed below.

Identification points of the tympanic membrane:

The handle of the malleus is a whitish tubercle descending to the center of the tympanic membrane. There is a small seal in its upper part - lateral process of malleus.

Behind and in front of the tympanic membrane, there are two stretch folds extending from the lateral process of the malleus. It's back and front hammer foldsand the portion of the tympanic membrane above forms the pars flaccida (loose tympanic membrane).

So, the main identifying points:

1. Eardrum navel
2. Hammer handle
3. Posterior hammer fold
4. Lateral process of the malleus
5. Anterior hammer fold
6. Light reflex (light cone).

The middle ear is divided into three parts: the upper part - attic - drum groove, mesotympanum - the tympanic cavity and hypotympanum - the lower part of the tympanic cavity.

The attic is the part of the middle ear located above the malleus folds. It is divided into pockets by the auditory ossicles, ligaments and mucous folds. In this area, an infection can be localized. It should be noted that the middle ear extends beyond the tympanic membrane.

The auditory bones of the middle ear

The middle ear contains three bones: the malleus, incus, and stirrup.

The handle of the hammer is firmly attached to the center of the eardrum. The base of the stirrup covers the window of the vestibule of the middle ear.

Tympanic membrane topography

Above is middle cranial fossa;

Mastoid (the largest cell, otherwise called the antrum or cave) is located behind. Before the eardrum carotid artery, from below jugular vein.

Outer (lateral) wall the tympanic cavity is formed by the tympanic membrane with its bony ring. Medial wall is the outer wall of the labyrinth and has two windows: an oval window (connected to the stirrup) and a round window closed by a membrane (secondary tympanic membrane).

Eustachian tube

The eustachian tube connects the eardrum to the nasopharynx. In adults, it is closed and opens when swallowing.

Functions:

Barometric (equalization of pressure in the middle ear almost to the level of external atmospheric pressure).

Drainage - withdrawal of secretion from the middle ear into the nasopharynx

Protective - protects the middle ear from infection penetrating from the nasopharynx (with airborne transmission of infection).

Characteristics of the Eustachian tube in children

1. The Eustachian tube is short, straight and wide. Compared to adults, it opens deeper into the nasopharynx.
2. The Eustachian tube is constantly open.
3. In newborns, the epithelium lining the tube is underdeveloped.

Middle ear characteristics of newborns

1. The embryonic myxoid tissue of the tympanic membrane can remain for up to three years.
2. There is no complete ossification of the wall of the tympanic cavity. There is a direct contact between the mucous membrane of the middle ear and the dura mater.

The eardrum is thicker than that of an adult. It is located almost horizontally, which makes it difficult to inspect.

Characteristics of the mastoid process of newborns

Newborns have only one pneumatic cell - the antrum or cave. Consequently, newborns do not have mastoiditis, but antritis is a frequent pathology at this age.

Nose and paranasal sinuses

External nose

The outer nose is supported by bone and cartilage. The bony part is formed mainly from the nasal bones on each side and the frontal process of the upper jaw. The cartilage is made up of several cartilages that support and shape the bottom and tip of the nose.

Nasal cavity

The nasal cavity is divided by the nasal septum into two parts that have the same anatomical structure, but they can be asymmetric.

Nasal septum

The septum of the nasal cavity consists of bone and cartilage tissue. The cartilaginous part of the septum is covered with perichondrium, bony periosteum and mucous membrane. A deviated septum often causes nasal congestion.

The lower front of the nose is called the bleeding zone or the Kisselbach zone. This is the area of \u200b\u200bnosebleeds.

Lateral wall of the nasal cavity

On the lateral wall there are conchas that delimit three nasal passages: upper, middle and lower. The inferior shell is formed by bone, the others are parts of the ethmoid bone. The mucous membrane is supplied with erectile tissue and numerous blood vessels.

The nasal passages play an important role, they are the drainage channels of the air sinuses. The appearance of pus in one of the passages is of diagnostic value for infections of the sinuses of the nose.

Nose functions

1. Filtration
2. Humidification and regulation of the temperature of the air entering the lungs.
3. Voice resonance
4. Aesthetic function

The functions of the nose are determined by the mucous membrane and its tissues. In some areas, such as the shell, it is a complex structure of the ciliary mucosa, glands, blood supply, and connective tissue on the bone, controlled by the autonomic nervous system. In this case, the shells act as a valve mechanism that expands or narrows the air channels and directs the air flow.

Ciliary activity

Cilia movement is the means by which the mucous membrane cleanses itself and removes unwanted materials. The movement of the cilia promotes the movement of mucus produced in the nose from the nostrils to the pharynx. Any disturbance in normal activity causes unpleasant symptoms. Dripping from the nose or "catarrh", which is most often complained about, is nothing more than the inability of the ciliary mechanism to cope with the thick mucus that slowly flows down the throat and accumulates there. The necessary conditions for normal ciliary activity are an appropriate mucus consistency and aeration.

Filtration and humidification

Dust, bacteria and other particles stick to the mucous membrane. The cilia, by contracting, remove them, moving them into the pharynx along with the mucus, where it is swallowed. This is how filtration.

Moisturizing and regulation of the temperature of the air entering the lungs is one of the main functions. Air enters the lungs at a temperature of about 30 ° C and 75-95% humidity. In the cold season, indoor air heats up and humidity drops. Regulating the moisture in the nose to a normal level can overstrain the nasal mechanism.

Smell disorder

Various factors can affect the sense of smell. For example, nasal congestion during inflammation can inhibit normal smelling function. Sometimes it is disturbed due to exposure to toxic substances or a head injury with a violation of nerve endings, as a result of which the perception of odors ceases.

Thus, if the patient has lost the ability to smell, this means the presence of:

• respiratory hyposmia (decreased sense of smell)
• general hyposmia.

Violation of vocal resonance occurs when the nose is stuffy. Then the person speaks through his nose and his voice takes on a nasal tone.

There are two types of nasalism:

1. closed nasal (nasal congestion)
2. open nasalness (the cause is a pathology of the nasal cavity or mouth, for example, a split palate, other defects)

Deformity of the nose

The nose is located in the center of the face. The shape of the outer nose is directly related to a person's attractiveness.

Paranasal sinuses

Eight paranasal sinuses (4 pairs) are located around the nasal cavity:

• maxillary sinuses
• frontal
• ethmoid sinus (divided into anterior and posterior)
• sphenoid sinus.

Functions of the paranasal sinuses

• Voice resonance
• Thermoregulation (the paranasal sinuses protect our brain from too high or low temperatures).
• Protective, they protect the brain and eyes from head injuries (like an airbag).
• They act as a powerful barrier protecting vital structures (cranial cavity and eye sockets) from infection.

Front group paranasal sinuses (maxillary, frontal and anterior ethmoid cells) communicate with middle passage.

Back group (posterior ethmoid cells and sphenoid sinuses) communicate with top passage.

Nasolacrimal duct communicates with the lower passage.

It should be noted that while the lower and middle passages are open at both ends, the frontal passage is closed in front. This means that with anterior rhinoscopy, the pus of the posterior group of the sinuses cannot be discerned.

Paranasal sinuses in children

In newborns, only the ethmoid sinus is well developed. Other sinuses are underdeveloped.

The development of the maxillary sinus is completed by 4-5 years of age. The frontal sinus has the longest developmental period - up to 11-13 years.

ENT organs: pharynx

The pharynx consists of three parts - nasal, oral and laryngeal.

Nasopharynx located above the soft palate line.

Oropharynx is below this line and extends to the tip of the epiglottis.

Hypopharynx, the larynx begins at the tip of the epiglottis and extends to the cricoid cartilage.

The pharynx communicates with adjacent organs through seven openings:

1. two choanas (with nasal cavity)
2. two openings of the ear canal (with the tympanic cavity)
3. throat (with the mouth)
4. laryngeal opening
5. esophageal aperture

Nasopharynx

At the junction of the palate and the back wall, there are accumulations of lymphoid tissue - adenoids or pharyngeal tonsils... Anteriorly, the nasopharynx is connected to the posterior choana of the nose, with the posterior ends of the three turbinates on each side and the posterior edge of the nasal septum in the middle.

There are holes in the side walls eustachian tube... Behind them tubal tonsils.

In children 5-6 years old, the tonsils are often enlarged. They can block the choans and cause nasal congestion.

Oropharynx

The nasopharynx and oropharynx are separated by a soft palate, a strong, movable muscular septum. A tongue hangs down in its middle part. On both sides of the palate, there are mucous-muscular folds that connect to the tongue. It's back and front temples pharynx.

Between the palatine arches is located palatine tonsil, below the base of the tongue, a collection of lymphoid tissue called lingual tonsil.

On the back wall of the oropharynx, there are numerous small accumulations of lymphoid tissue, which under certain conditions can increase and become inflamed.

Lymphoepithelial ring of the pharynx

The lymphoepithelial ring of the pharynx consists of 6 tonsils (3 in the nasopharynx, 3 in the oropharynx):

• two palatine tonsils,
• two tubal tonsils,
• pharyngeal tonsil,
• lingual tonsil.

Hypopharynx (hypopharynx)

This is the part of the pharynx that is flush with the larynx. Between the base of the tongue and the anterior part of the larynx are two hollows... They are separated in the middle by the lingual-epiglottis ligament and bounded behind by the pharyngo-epiglottis ligament. These are folds of the mucous membrane that join the back of the base of the larynx. Behind these bundles begin pear-shaped apertures one on each side.

Larynx

The larynx consists of a cartilaginous base connected by ligaments and covered with muscles and mucous membranes. Paired and unpaired cartilages are distinguished.

Paired cartilage:

1. arytenoid,
2. horn-shaped
3. wedge-shaped.

Unpaired cartilage:

1. cricoid
2. thyroid
3. epiglottis

In the depths of the larynx, there are two folds of the mucous membrane of pink color, stretching in the direction from front to back. it false vocal cords... There is a space between the true and false vocal cords, called ventricles larynx. The lower lip of the ventricle is formed by a muscle bundle - true vocal cords... When viewed from above, they are whitish in color and narrow in shape.

Pharyngeal cavity

In the pharyngeal cavity, there are:

• The vestibule of the pharynx (above the false vocal cords)
• Middle space (between the false and true vocal cords).
• The subglottic space (below the vocal cords) is the narrowest part of the pharynx.

The middle ear is located in the thickness of the temporal bone pyramid and consists of interconnecting cavities: the tympanic cavity, the auditory tube (Eustachian), the cave and the cells of the mastoid process. The volume of the tympanic cavity is 1 cm3.

There are three parts of the tympanic cavity: the upper (epitympanum) is located above the upper edge of the tympanic membrane. The middle (mesotympanum) corresponds to the stretched part of the tympanic membrane. The lower (hypotympanum) is located below the level of the tympanic membrane. The tympanic cavity has 6 walls. The upper one is bordered by the middle cranial fossa and the temporal lobe of the brain. The lower one is bordered by the jugular vein. The outer wall is the tympanic membrane itself. The posterior wall is bordered and communicated with the mastoid process. The anterior wall is bordered by the internal carotid artery. The inner wall is formed by the outer wall of the inner ear. There are two windows in the wall of the inner ear. The oval window is closed by a stirrup plate, the round window is covered with a secondary membrane. In the tympanic cavity there is a chain of ossicles. These are the hammer, anvil and stirrup. The handle of the malleus is spliced \u200b\u200bwith the membrane itself, and the head of the malleus is connected by a joint to the incus. The anvil is connected by a joint to the head of the stapes. The walls of the tympanic cavity, auditory tube, antrum and mastoid are lined with mucous membrane. The auditory tube connects the tympanic cavity to the nasopharynx. Functions of the auditory tube: drainage (carried out due to the work of the ciliated epithelium), ventilation, barofunction (equalization of pressure in the middle ear), auditory. The mastoid process contains air cells lined with mucous membrane, communicating with each other by holes.

1. Clinical anatomy and physiology of the inner ear

The inner ear or labyrinth is located deep in the pyramid of the temporal bone and consists of a bone labyrinth and a membranous labyrinth located in it. Between the bone labyrinth and the membranous labyrinth located inside it, there is a liquid - perilymph. The membranous labyrinth contains fluid - endolymph. The central part of the labyrinth is called the vestibule. It communicates in front with the cochlea, behind with semicircular canals. The semicircular canals are located in three mutually perpendicular planes.

The bone cochlea consists of a canal spirally wound around the shaft. A spiral plate extends from the rod into the channel lumen, which winds around the rod like a spiral staircase. Its width narrows towards the top. The continuation of the spiral plate is the main membrane, reaching the opposite wall of the bone canal. Thus, the shortest membrane fibers are located at the base of the cochlea, and the longest at the apex. The membranous labyrinth is suspended in the perilymph, which fills the bony labyrinth. In the membranous labyrinth, two devices are distinguished: vestibular and auditory.

The vestibular apparatus consists of sacs of the vestibule and semicircular canals. On the inner surface of the vestibule sacs there is a receptor apparatus, consisting of hair and supporting cells. Above them is a jelly-like mass with inclusions of microcrystals (otolithic or statoconium membrane). It irritates the receptor apparatus and initiates the emergence of a nerve impulse entering the subcortical vestibular formations.

The hearing aid is located in the membranous cochlea. It is located on the tympanic wall of the cochlear duct and consists of hair and supporting cells. Above the spiral organ is the integumentary membrane, into which the hairs of neuroepithelial hair cells penetrate. When the membrane vibrates, the hairs are irritated and a nerve impulse arises. The processes of neuroepithelial cells form the auditory nerve. It carries information to the corresponding parts of the cerebral cortex (temporal lobe). Here, the analysis and synthesis of information from the receptor apparatus arriving through the vestibulo-cochlear nerve takes place.

In the tympanic cavity there are three sections (floors): 1) the upper section is the tympanic space, the attic (recessus epitympanicus, epitympanum) is located above the short process of the malleus; 2) the middle section (atrium, mesotympanum) - between the short process and the bottom of the external auditory canal; 3) lower section - basement (recessus hypotympanicus, hypotympanum) - below the level of the bottom of the external auditory canal.

The walls of the tympanic cavity... The outer (lateral) wall of the tympanic cavity (paries membranaceus) is formed by the tympanic membrane with its bony ring. Of particular importance is the bony part of the lateral wall (above the tympanic membrane), which is the most medial section of the upper wall of the bony external auditory canal, formed by the scales of the temporal bone.

Bony part of the lateral wall below the tympanic membrane is represented, respectively, by the lower wall of the bony auditory canal. Anterior to the upper part of the tympanic membrane, on the lateral wall of the tympanic cavity, there is a glazer gap leading to the glenoid fossa for the lower jaw. The drum string comes out of the drum cavity through the slit.

Inflammatory process can spread along this path from the tympanic cavity to the mandibular joint [observation of Volger]. The inner (medial, labyrinth, promontorial) step of the tympanic cavity (paries labyrinthicus) is at the same time part of the outer wall of the labyrinth capsule. Most of the wall, its middle, is occupied by a protrusion formed by the outer wall of the end part of the main curl of the snail, the so-called promontorium (cape). The cape is clearly delimited along the periphery from the medial wall of the tympanic cavity and only in the anteroposterior part without a pronounced border passes into the inner wall of the Eustachian tube.

In the rear-lower part cape breaks off rather abruptly, forming a sharp leading edge of a round window niche, turning into its canopy. Now, above the cape and behind it, a depression (niche) adjoins it, at the bottom of which there is an oval window-fenestra vestibuli s. ovalis leading to the threshold of the maze. The oval window has a direction from above and from the front, downward and backward. The edges of the window are covered with elastic fibrous cartilage. The longitudinal diameter of the window is 3 mm, the transverse diameter is 1.2-1.5 mm.

Oval window closed stirrup, or rather its foot plate, surrounded by an annular ligament (lig. annulare), immediately adjacent to the edges of the window.
About at the same level as the oval window, a pyramidal protrusion (eminentia s. processus pyramidalis) protrudes into the tympanic cavity at the border with its posterior wall. Through a small hole in the anterosuperior pole of this elevation passes the tendon of the stapes (m. Stapedius), which then attaches to the head of the stapes. This elevation is the result of ossification of the connective tissue membrane of the stapes muscle.

Medial wall of the tympanic cavity almost not the entire length passes without a pronounced border into the posterior wall of the cavity, and only immediately below the pyramidal protrusion between both walls an angle is formed, or rather a depression, - sinus tympani (between the wall of the fallopian canal from the lateral side and the labyrinthine wall from the medial side). Directly above the cape, between it and the roof of the tympanic cavity, there is a semicanalis m. tensor tympani (half-channel of the muscle straining the eardrum), ending under the oval window, immediately in front of it, with a spoon-shaped protrusion-processus cochleariformis.

Thus, anterior and posterior edges of the oval window are delimited, respectively, by said protrusion and a pyramidal protrusion. From this protrusion, the tendon of the mentioned muscle stretches to the handle of the hammer. The specified semi-canal is separated by a thin bone septum from the semi-canal of the bony part of the Eustachian tube (semicanalis tubae auditivae) located under it, together with which it forms canalis musculotubarius.

The tympanic cavity, cavum tympani, or middle ear, auris media, is a cavity located between the tympanic membrane and the labyrinth. Its shape resembles a biconcave lens with six walls: top, bottom, front, back, outer and inner.

The length and width of the tympanic cavity, i.e., its anteroposterior size and its height, are almost the same - about 1.5 cm.The outer-inner size (depth of the tympanic cavity) from the tympanic membrane to the labyrinth is about 6 mm at the top, 4 mm at the bottom and only 1, 5–2 mm in the middle. The latter depends on the fact that the tympanic membrane is concave, and there is an elevation on the labyrinth wall - a promontorium (Fig. 36 and 37).

The walls of the tympanic cavity

I. Paries superior - the upper wall of the drum cavity is formed by its roof, tegnren tympani. It is represented by a thin plate protruding in the form of a mound into the cavity of the middle cranial fossa. This plate is dotted with many of the finest openings that communicate the tympanic cavity with the middle cranial fossa. Through these openings, the vessels of the tympanic cavity are branches a. tympanica and veins of the same name anastomose with the vessels of the middle cranial fossa - branches of a. meningea media. A particularly large number of these holes are located on the border between the pyramid and the scales of the temporal bone. Here, in the embryonic period, a gap is preserved - fissura petrosquamosa, and in the definitive state - numerous holes. Through these holes, both in the paries tegmentalis itself and in the area of \u200b\u200bthe former fissura petrosquamosa, a chronic infection

Fig. 36. The external auditory canal and tympanic cavity (according to Corning).

1 - external auditory canal; 2 - eardrum; 3 - middle ear cavity; 4 - the threshold; 5 - n. vestibuli; c - n. cochleae; 1 - bulbus v. jugularis.

in inflammatory processes, the middle ear cavity can penetrate into the middle cranial fossa and cause an abscess in the temporal lobe of the cerebral hemispheres.

II. Paries jugularis - the jugular or lower wall of the tympanic cavity - is represented by the jugular fossa, fossa jugularis. Unlike the top, the bottom wall is concave. This wall is also very thin. From the presence of pus in the tympanic cavity, which accumulates on the lower wall due to gravity, bone usura can gradually occur and an abscess breakthrough directly into the bulbus venae jugularis with the development of septicopyemia. This is a very significant clinical significance of the lower wall.

On this wall there is a hole - apertura inferior canaliculi tympanici, located at the bottom of the fossula petrosa, through which n penetrates into the tympanic cavity. tympanicus (Jacobsoni).

III. Paries tubarius s. caroticus - tubal or carotid wall - is the front wall of the tympanic cavity; formed by the muscular-tubal canal, canalis musculotubarius, and the adjacent carotid canal canalis caroticus, for the internal carotid artery canalis musculotubarius is subdivided into two semicanals: the upper one - semicanalis m. tensoris tympani and lower - semicanalis tubae auditivae.

The Eustachian tube consists of bone, pars ossea, and cartilaginous, pars fibrocartilaginea, parts. The bony part is enclosed in semicanalis tubae auditivae; the cartilaginous part is a continuation of the bone and ends with the pharyngeal opening - ostium pharyngeum within the upper lateral part of the pharynx. Its length is about 4 cm; function - conducting air into the tympanic cavity and removing mucus from the middle ear cavity. The lumen of the Eustachian tube is not the same: the tympanic opening is 5–6 mm, the pharyngeal opening is about 8 mm. The narrowest point is the border between the bone and cartilaginous parts.

Fig. 37. Mastoid process and tympanic cavity in the section (according to Corning).

1 - cellulae mastoideum; 2 - antrum mastoideum; 3 - processus pyramidalis and tendon m. stapedii; 4 - stirrup; 5 - tendon m. tensoris tympani; 6 - m. tensor tympani; 7 - n. petrosus superficialis major; 8 - pars ossea tubae auditivae; 9 - promontorium and sulcus tympanicus; 10 - fenestra cochleae and m. stapedius; 11 - n. facialis.

The mucous membrane lining the Eustachian tube, with catarrhal swelling, closes the lumen of the tube, which is immediately reflected in hearing.

The anterior wall of the tympanic cavity has a double clinical significance: firstly, through the Eustachian tube, oral infection can penetrate into the middle ear cavity and cause inflammation (ascending infection); secondly, all the lymphatic vessels of the tympanic cavity are directed along the Eustachian tube into the retropharyngeal lymph nodes, l-di retropharyngeae. For this reason, with purulent inflammation of the middle ear, infection by the lymphogenous way penetrates into the pharyngeal lymph nodes, causing first their enlargement, and then melting with the development of the pharyngeal abscesses. Such abscesses are especially common in children.

IV. Paries mastoideus - mastoid wall - is the back wall of the tympanic cavity, directed back to the mastoid process. In the upper part of this wall there is a wide entrance aditus ad antrum into the expanded cell of the mastoid process - antrum mastoideum; below is the tympanic opening of the canal of the drum string, apertura tympanica canaliculi chordae, through which chorda tympani penetrates into the tympanic cavity from the facial nerve.

In the upper part of the wall, there is a ledge - a pyramidal process, processus pyramidalis, from which m. stapedius.

Clinically, this wall is also important, since in chronic inflammation of the middle ear cavity, infection per continuitatem through the aditus ad antrum in the mucous membrane penetrates the antrum mastoideum and the adjacent cells of the mastoid process of the cellulae mastoideae, causing antritis in children and mastoiditis in adults.

V. Paries labyrinthicus - labyrinth wall - is the inner wall of the tympanic cavity; it separates the middle ear cavity from the labyrinth. On this wall there is a number of anatomical structures, located, if you go from top to bottom, in the following order: above all, in the horizontal direction is the elevation of the external semicircular canal canalis semicircularis lateralis. When performing a radical operation of mastoiditis with the removal of the tympanic ossicles, incus and malleus, this canal can be damaged, as it is close to the area of \u200b\u200bthe operating field. Below is the elevation of the facial nerve, prominentia canalis facialis, also located in the horizontal direction. It contains the fallopian canal or the canal of the facial nerve. The surface of the canal protruding into the middle ear cavity is thin and speckled with a large number of small holes. In these areas, the mucous membrane of the tympanic cavity is adjacent directly to the epineural membrane of the facial nerve. This explains the often occurring paresis and paralysis of the facial nerve with purulent inflammation of the middle ear cavity, since the infection from the mucous membrane easily penetrates the canal of the facial nerve. Below is an oval window, fenestra ovalis, covered by the base of the stapes, basis stapedis. Even lower is the promontorium - a promontory, in the form of an elevation, protruding into the middle ear cavity. It branches out n. tympanicus, forming the so-called Jacobsonian plexus. The lowest is the round window, fenestra rotunda, covered with a secondary tympanic membrane, membrana tympanica secundaria; it leads to the snail.

Vi. Paries membranaceus - membranous wall - is the outer wall of the tympanic cavity; it is formed in the lower part of the tympanic membrane, and at the top by the bone substance, since the dimensions of the tympanic membrane (about 1 cm in diameter) are somewhat smaller than the outer wall of the middle ear cavity.

The tympanic membrane, membrana tympani, is enclosed in the tympanic groove, sulcus tympanicus, and is divided into two parts: tense, pars tensa, and non-tense, pars flaccida. The first is fixed in the mentioned tympanic groove, the second - in a special notch - incisura tympanica (Rivini), located in the anteroposterior part of the tympanic ring, annulus tympanicus.

The tympanic membrane is concave, its top is called the navel of the tympanic membrane, umbo membranae tympani.

The tympanic membrane consists of three layers: outer - skin, stratum cutaneum, inner - mucous membrane, stratum mucosum, and middle - lamina propria, formed by fibrous connective tissue.

When otoscopy from the navel of the tympanic membrane upward and anteriorly, a strip is visible, stria malleolaris, depending on the translucent handle of the hammer, manubrium mallei. From here, a light reflex in the form of a light cone is noticeable, the base is open anteriorly and downward, and the top is directed to the navel.

For practical purposes, the eardrum is divided into four quadrants. One line is drawn through the handle of the hammer, the second is drawn perpendicular to it through the navel. Punctures (paracentesis) of the tympanic membrane are best done in the anterior inferior quadrant: in the anterior part of the tympanic membrane - so as not to puncture the thin wall of the paries jugularis and not injure the bulbus venae jugularis; in the lower part of the tympanic membrane - for better drainage of pus.

The eardrum is supplied with blood from two sources: its outer surface - due to a. auricularis profunda (a.maxillaris interna); inner surface - from a. tympanica (also from a.maxillaris interna).

Eardrum nerves: its outer surface innervates ramus auricularis n. vagi and n. auriculotemporalis; the inner surface is innervated by branches n. tympanicus.

The middle ear cavity is divided into three levels: upper, middle and lower.

Epitympanicum - the upper floor of the tympanic cavity, otherwise the attic, is a small cavity enclosed inward from the pars flaccida membranae tympani.

Borders: top tegmen tympani; below - a conditional border at the level of fenestra ovalis; in front - processus cochleariformis; behind - aditus ad antrum; outside the attic is limited by pars flaccida membranae tympani; from the inside - prominentia canalis semicircularis lateralis and prominentia canalis facialis.

The attic contains most of the body of the malleus and the incus.

Mesotympanicum - the middle floor of the tympanic cavity - is the narrowest part of the tympanic cavity and is enclosed between the promontory and the tense part of the tympanic membrane. Hypotympanicum - the lower floor of the tympanic cavity - is a depression separated by a thin bone plate from the fossa jugularis, where the bulbus venae jugularis is located.

We have already mentioned that pus accumulates in this depression during inflammation of the middle ear, which can break through into the bulbus venae jugularis.

The blood supply to the tympanic cavity is carried out from a. tympanica. Being a branch of the first segment a. maxillaris interna, this vessel penetrates through fissura petrotympanica (Glaseri) into the tympanic cavity, where it branches into the thickness of the mucous membrane.

The second vessel is a. stylomastoidea (from a. auricularis posterior), which enters the foramen stylomastoideum, supplies the facial nerve with blood and the terminal branches passing through the numerous openings of the prominentia canalis facialis, anastomoses with the branches of a. tympanica. The third source of blood supply is a. meningea media, which sends thin twigs through the holes of the paries tegmentalis into the tympanic cavity. Venous outflow from the tympanic cavity is carried out through the veins of the same name.

The innervation of the tympanic cavity occurs due to n. tympanicus from the IX pair of cranial nerves. Having entered the tympanic cavity through apertura inferior canaliculi tympanici (from ganglion petrosum), the nerve lies on the promontorium and forms the tympanic plexus (Jacobson's), plexus tympanicus (Jacobsoni), which branches widely throughout the tympanic cavity.

Lymphatic drainage from the tympanic cavity follows the course of the mucous membrane of the Eustachian tube into the retropharyngeal lymph nodes, 1-di retropharyngeae.

Inner ear

The inner ear, auris interna, consists of a bony labyrinth, labyrinthus osseus, and the membranous labyrinth included in it, labyrinthus membranaceus.

The inner ear is divided into three parts: the vestibule, the vestibulum, the three semicircular canals, canales semicirculares, and the cochlea, cochlea.

1. The vestibule looks like a small cavity, divided into two pockets: a spherical pocket, recessus ellipticus, and an elliptical pocket, recessus sphericus. In the first lies the so-called spherical sac, sacculus, in the second, an elliptical sac, utriculus.

Utriculus is connected to the semicircular canals by five openings.

On the outer wall of the vestibule there is an oval window, fenestra vestibuli, covered from the side of the middle ear by the base of the stapes.

2. Three semicircular canals are located in three mutually perpendicular planes.

a) Canalis semicircularis lateralis - external semicircular canal - located in the horizontal plane. In the cavum tympani area, it forms an elevation - prominentia canalis semicircularis lateralis. This canal is most important in practical terms: one should know its topography and remember that it can be accidentally damaged during a radical operation of mastoiditis.

b) Canalis semicircularis superior - the upper semicircular canal - lies in the frontal plane.

c) Canalis semicircularis posterior - posterior semicircular canal - located in the sagittal plane.

3. The cochlea, cochlea, is a spiral channel with 2 1/2 turns. It has a base, basis cochleae, directed to the middle ear, and an apex, cupula cochleae, which is a continuation of the rod, modiolus. The base of the snail - its first curl - protrudes into the tympanic cavity, forming a promontorium.

Inside the cochlea, there is a spiral channel, canalis spiralis. The axis of the cochlea is formed by its rod, modiolus, from which a helical spiral plate, lamina spiralis, departs. She divides the channel of the cochlea into two spiral corridors - upper and lower.

The upper corridor is the vestibule staircase, scala vestibuli, the lower corridor is the drum staircase, scala tympani. Both corridors are isolated from each other and only at the apex of the cochlea communicate with each other by a special opening, the helicotrema.

The membranous labyrinth, labyrinthus membranaceus, partly repeats the shape of the bone labyrinth.

Between the bone and membranous labyrinths, there is a liquid - perilymph. Inside the membranous labyrinth there is also a liquid - endolymph.

The sound-receiving apparatus is a spiral organ, organon spirale (Cortii), an epithelial formation that lies in the main plate, lamina basilaris, of the snail.

Impulses emanating from the spiral organ follow from the apex of the cochlea along the auditory nerve lying in the meatus acusticus internus to the auditory tubercle, tuberculum acusticum, the bottom of the rhomboid fossa.