The pharynx is a funnel-like muscular canal that is up to 14 cm long. The anatomy of this organ allows the food bolus to freely enter the esophagus, and then into the stomach. In addition, due to anatomical and physiological features, air penetrates through the pharynx from the nose into the lungs and into reverse side. That is, the human digestive and respiratory systems intersect in the pharynx.

Anatomical and physiological features

The upper part of the pharynx is attached to the base of the skull, occipital bone and temporal pyramidal bones. At the level of the 6th-7th vertebrae, the pharynx passes into the esophagus.

Inside it is a cavity (cavitas pharyngis). That is, the pharynx is a cavity.

The organ is located behind the oral and nasal cavities, anterior to the occipital bone (its basilar part) and the upper cervical vertebrae. In accordance with the relationship of the pharynx to other organs (that is, with the structure, it is conditionally divided into several parts: pars laryngea, pars laryngea, pars nasalis. One of the walls (upper), which is adjacent to the base of the skull, is called the vault.

Bow

Pars nasalis in functional terms is respiratory section human throat. The walls of this section are motionless and therefore do not collapse (the main difference from other sections of the organ).

In the anterior wall of the pharynx there are choanae, and on the lateral surfaces there are pharyngeal funnel-shaped openings auditory tube, which is a component of the middle ear. At the back and above, this opening is limited by the tubal ridge, which is formed by the protrusion of the cartilage of the auditory tube.

The border between the posterior and upper walls of the pharynx is occupied by accumulation lymphoid tissue(on the midline) called adenoids, which are little pronounced in an adult.

Between the soft palate and the opening (pharyngeal) of the tube there is another accumulation of lymphatic tissue. That is, at the entrance to the pharynx there is an almost dense ring of lymphatic tissue: lingual tonsil, palatine tonsils (two), pharyngeal and tubal tonsils (two).

Oral part

Pars oralis is the middle section in the pharynx, communicating in front through the pharynx with the oral cavity, and its posterior part is located at the level of the third cervical vertebra. The functions of the mouth are mixed, due to the fact that the digestive and respiratory systems intersect here.

This crossover is a feature respiratory system human and was formed during periods from the primary intestine (its wall). From the rhinooral primary bay the oral and nasal cavity, the latter being located above and slightly dorsally relative to oral cavity. The trachea, larynx and lungs developed from the wall of the (ventral) foregut. That is why the head section of the gastrointestinal tract is located between the nasal cavity (above and dorsally) and respiratory tract(ventrally), which explains the intersection of the respiratory and digestive systems in the pharynx area.

Laryngeal part

Pars laryngea is bottom organ, located behind the larynx and runs from the beginning of the larynx to the beginning of the esophagus. The laryngeal entrance is located on its anterior wall.

Structure and functions of the pharynx

The basis of the pharyngeal wall is that it is attached from above to the bony base of the skull, lined inside with mucous membrane, and outside with muscular membrane. The latter is covered with thin fibrous tissue, which unites the pharyngeal wall with neighboring organs, and from above, passes to m. buccinator and turns into her fascia.

The mucous membrane in the nasal segment of the pharynx is covered with ciliated epithelium, which corresponds to its respiratory function, and in the underlying sections - with flat stratified epithelium, due to which the surface becomes smooth and the food bolus easily slips when swallowing. In this process, the glands and muscles of the pharynx also play a role, which are located circularly (constrictors) and longitudinally (dilators).

The circular layer is more developed and consists of three constrictors: the superior constrictor, the middle constrictor and the inferior constrictor of the pharynx. Starting at various levels: from the bones of the base of the skull, the lower jaw, the root of the tongue, the cartilages of the larynx and the hyoid bone, the muscle fibers are directed back and, uniting, form a suture of the pharynx along the midline.

The fibers (inferior) of the inferior constrictor are connected to the muscle fibers of the esophagus.

The longitudinal muscle fibers make up the following muscles: stylopharyngeus (M. stylopharyngeus) originates from the styloid process (part of the temporal bone), passes down and, dividing into two bundles, enters the wall of the pharynx, and is also attached to (its upper edge); velopharyngeal muscle (M. palatopharyngeus).

The act of swallowing

Due to the presence of the intersection of the digestive and respiratory tracts in the pharynx, the body is equipped with special devices that separate the respiratory tract from the digestive tract during swallowing. Thanks to the contractions, the lump of food is pressed against the palate (hard) with the back of the tongue and then pushed into the pharynx. At this time, the soft palate is pulled upward (due to contractions of the tensor veli paratini and levator veli palatini muscles). So the nasal (respiratory) part of the pharynx is completely separated from the oral part.

At the same time, the muscles located above the hyoid bone pull the larynx upward. At the same time, the root of the tongue moves down and presses on the epiglottis, due to which the latter descends, closing the passage to the larynx. Subsequently, successive contractions of the constrictors occur, due to which the bolus of food penetrates the esophagus. In this case, the longitudinal muscles of the pharynx work as lifters, that is, they raise the pharynx towards the movement of the food bolus.

Blood supply and innervation of the pharynx

The pharynx is supplied with blood mainly from the pharyngeal ascending artery (1), the superior thyroid artery (3) and the branches of the facial (2), maxillary and carotid external arteries. Venous outflow occurs into the plexus, which is located on top of the pharyngeal muscular layer, and then along the pharyngeal veins (4) into the internal jugular vein (5).

Lymph flows into the lymphatic cervical nodes(deep and retropharyngeal).

The pharynx is innervated by the pharyngeal plexus (plexus pharyngeus), which is formed by branches of the vagus nerve (6), sympathetic nerve (7) and glossopharyngeal nerve. Sensitive innervation passes through the glossopharyngeal and vagus nerve, the only exception is the stylopharyngeal muscle, which is innervated only by the glossopharyngeal nerve.

Dimensions

As mentioned above, the pharynx is a muscular tube. Its largest transverse dimension is at the levels of the nasal and oral cavities. The size of the pharynx (its length) is on average 12-14 cm. The transverse size of the organ is 4.5 cm, that is, larger than the anteroposterior size.

Diseases

All diseases of the pharynx can be divided into several groups:

• Inflammatory acute pathologies.
• Injuries and foreign bodies.
• Chronic processes.
• Tonsil lesions.
• Sore throats.

Inflammatory acute processes

Among the inflammatory diseases that occur acutely, the following can be distinguished:

• Acute pharyngitis is damage to the lymphoid tissue of the pharynx due to the proliferation of viruses, fungi or bacteria in it.
• Candidiasis of the pharynx - damage to the mucous membrane of the organ by fungi of the genus Candida.
• Acute tonsillitis (tonsillitis) is a primary lesion of the tonsils, which is infectious in nature. Angina can be: catarrhal, lacunar, follicular, ulcerative film.
• An abscess in the area of ​​the root of the tongue is purulent tissue damage in the area of ​​the hyoid muscle. The cause of this pathology is infection of wounds or as a complication of inflammation of the lingual tonsil.

Injuries to the pharynx

The most common injuries are:

1. Various burns caused by electrical, radiation, thermal or chemical exposure. Thermal burns develop due to exposure to too hot food, and chemical burns - when exposed to chemical agents (usually acids or alkalis). There are several degrees of tissue damage from burns:

• The first degree is characterized by erythema.
• The second degree is the formation of bubbles.
• Third degree - necrotic tissue changes.

2. Foreign bodies in the pharynx. These could be bones, pins, food particles, and so on. The clinical picture of such injuries depends on the depth of penetration, localization, and size of the foreign body. Occur more often stabbing pains, and then pain when swallowing, coughing or a feeling of suffocation.

Chronic processes

Among chronic lesions of the pharynx, the following are often diagnosed:

• Chronic pharyngitis is a disease characterized by lesions of the mucous membrane of the pharyngeal posterior wall and lymphoid tissue as a result of acute or chronic damage to the tonsils, paranasal sinuses, and so on.
• Pharyngomycosis is damage to the tissues of the pharynx caused by yeast-like fungi and developing against the background of immunodeficiency.
• Chronic tonsillitis is an autoimmune pathology of the palatine tonsils. In addition, the disease is allergic-infectious and is accompanied by a persistent inflammatory process in the tissues of the tonsils.

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Anatomy of the pharynx

Topography

The pharynx is an anatomical and functional system, including epithelial, glandular, connective tissue lymphoid, muscle and nervous structures that provide respiratory, swallowing, protective, immunobiological, vocal, resonator and articulatory functions.

The pharynx starts from the base of the skull and extends to the lower edge of the VI cervical vertebra, where it narrows in a funnel-shaped manner and passes into the esophagus. It has the shape of a groove, open anteriorly: at the top - towards the choanae, in the middle part - towards the pharynx, at the bottom - towards the entrance to the larynx. Down the pharynx narrows, passing into the esophagus at the level upper esophageal sphincter. This sphincter is located at a distance from the incisors upper jaw 17-18 cm and has a length of 25-30 mm. Behind the pharynx are the bodies of the cervical vertebrae with the deep muscles of the neck and prevertebral fascia covering them.

With pharyngoscopy, the oral cavity, lateral and posterior walls of the oropharynx, soft palate, palatine tonsils and other anatomical formations become visible (Fig. 1).

Rice. 1. Oral cavity and isthmus of pharynx (according to I. Dmitrienko, 1998): 1 - upper lip; 2 - palatal suture; 3 - pterygomandibular fold; 4 - pharynx; 5 - frenulum of the lower lip; 6 - lower lip; 7 - tongue; 8 - palatoglossal arch (anterior palatal arch); 9 - palatine tonsil; 10 - palatopharyngeal arch (posterior palatine arch); 11 - supramyngdal fossa; 12 - tongue; 13 - soft palate; 14 - hard palate; 15 - gums; 16 - vestibule of the mouth; 17 - frenulum of the upper lip

The pharynx is divided into upper, middle and lower parts.

Upper part, or nasopharynx(Fig. 2), extends from the base of the skull to the level of the soft palate (17). Its arch borders with the main one (7, 8) and partially with occipital bone, posterior wall - with the I and II cervical vertebrae (14, 16). Anteriorly, through the choanae, the nasopharynx opens into the nasal cavity. On the posterior and posterosuperior surface of the nasopharynx there is an accumulation of lymphadenoid tissue that forms pharyngeal tonsil(11). On the lateral walls of the pharynx at the level of the posterior ends of the inferior nasal conchae there are nasopharyngeal openings of the auditory tubes(15), which are surrounded above and behind pipe rollers(13), protruding into the lumen of the nasopharynx.

Rice. 2. The pharynx in a sagittal section (according to I. Dmitrienko, 1998): 1 - frontal sinus; 2 - cockscomb; 3 - sieve plate; 4 — deepening of the main bone; 5 - pituitary fossa; 6 — back of the saddle; 7 - sinus of the main bone; 8 - slope of the main bone; 9 - upper nasal passage; 10 - middle nasal passage; 11 - pharyngeal tonsil; 12 - nasal part of the pharynx (nasopharynx); 13 - pharyngeal eminence of the auditory tube; 14 - anterior arch of the atlas; 15 - nasopharyngeal opening of the auditory tube; 16 - body of the second cervical vertebra; 17 - soft palate; 18 - oral cavity; 19 - oropharynx; 20 - epiglottis; 21 - hypopharynx and upper esophagus; 22 — plate of the cricoid cartilage; 23 - trachea; 24 - part of the arytenoid cartilage; 25 - horn-shaped cartilage; 26 - vestibule of the larynx; 27 - thyroid gland; 28 - part of the arch of the cricoid cartilage; 29 - vocal fold; 30 - ventricle of the larynx; 31 - fold of the vestibule; 32 - thyroid membrane; 33 - hyoid bone; 34 - mylohyoid muscle; 35 - geniohyoid muscle; 36 - lower jaw; 37 - root of the tongue and lingual tonsil; 38 - blind hole; 39 - genioglossus muscle; 40 - back of the tongue; 41 - tip of the tongue; 42 - lower lip of the mouth; 43 - vestibule of the mouth; 44 - upper lip of the mouth; 45 - hard palate; 46 - lower nasal passage; 47 - vestibule of the nose; 48 - inferior nasal concha; 49 - nasal threshold; 50 - middle nasal concha; 51 - nasal bone; 52 - superior nasal concha; 53 - nasal spine of the frontal bone

The nasopharyngeal openings of the auditory tubes are associated with a number of anatomical formations that exert a mechanical effect on them and contribute to their opening or closing during the act of swallowing and breathing through the nose. These formations include: narrow tubopalatine fold mucous membrane and tubopharyngeal fold, in which bundles of muscle fibers lie from superior pharyngeal constrictor. Behind the tubopharyngeal fold at the mouth of the auditory tube is deepening of the pharynx, in the mucous membrane of which there are accumulations of lymphadenoid tissue ( pharyngeal eminence of the auditory tube, 13), with hyperplasia of which is formed tubal tonsil.

Middle part of the throat, or oropharynx, borders the pharynx in front (Fig. 1, 4 ), which is limited from above by the soft palate (vera palatine. 13), from the sides posterior palatal arch(10), from below - by the root of the tongue. Between the front and rear arms are located tonsils(9). The soft palate is a continuation hard palate and is an extremely mobile muscular plate, in the middle of which there is tongue(uvula,12). At rest, the soft palate hangs freely towards the root of the tongue, leaving a free communication between the nasopharynx and oropharynx. During the act of swallowing or when pronouncing the sounds “k” or “x”, the velum palatine is pressed tightly against the back wall of the pharynx and hermetically separates it from the nasopharynx.

The lateral wall of the pharynx and the area of ​​the palatine tonsils has a large clinical significance. More lateral is the neurovascular bundle. Closest to the palatine tonsil is located internal carotid artery, the distance of which from the upper pole of the tonsil is on average 1.5-2 cm. However, in some cases it is located in close proximity to the tonsil or immediately under its capsule, which should be taken into account when performing surgical interventions in this area. The lower pole of the tonsil is at the level external carotid artery, which is located at a distance of 1-1.5 cm from it. At this level, such large arteries depart from the external carotid artery as facial, lingual, ascending palatine, which are directed anteriorly. This is where it leaves tonsillar artery.

Lower part of the throat, or hypopharynx, is the most functionally important section of the pharynx, since it is here that the air and digestive tracts intersect and the voluntary phase of the act of swallowing ends. The hypopharynx begins at the level of the upper edge of the epiglottis (see Fig. 2, 20 ) and, tapering downwards in the form of a funnel, is located behind the bodies of the IV, V and VI cervical vertebrae. The entrance to the latter, formed by the cartilages and ligaments of the larynx, protrudes into the lumen of its lower part from below and in front - vestibule of the larynx(26). On the sides of the vestibule there are deep, slit-like cavities extending downwards ( pear-shaped pockets), which at the level of the plate of the cricoid cartilage (22) and behind it are connected into a common passage that passes into the esophagus (21). At rest, the cavity of this passage is in a collapsed state. On the anterior wall of the lower part of the pharynx, formed by the root of the tongue, is the lingual tonsil (37).

The basis of the pharynx is fibrous layer, located under the mucous membrane, with the help of which the pharynx is fixed to the base of the skull. The mucous membrane of the pharynx contains many mucous glands. The submucosal layer, immediately adjacent to the fibrous layer, contains lymphoid nodules, from which lymph flows through separate lymphatic vessels to the external submandibular lymph nodes.

Muscle layer the pharynx is formed by two groups of striated muscles - compressors And lifters throats. The constrictors are grouped into three circularly arranged groups of fibers, forming the upper, middle and lower constrictors. The levator pharyngeal muscles run longitudinally; at the top they are attached to the bones of the base of the skull; going down, they are woven into the walls of the pharynx at different levels and thus ensure its peristaltic mobility as a whole.

The most important longitudinal muscles of the pharynx are pharyngeal-palatine, styloglossus, inferior and external pterygoid, styloglossus, genioglossus, geniohyoid etc. The muscles that elevate the pharynx function in close interaction with the external muscles of the larynx and together with them participate in the act of swallowing.

Blood supply and lymphatic drainage

The blood supply and lymphatic drainage system of the pharynx is of great clinical importance, since the function of trophic and immune support of the pharynx and many pathological processes arising from this area are associated with this system.

The main source of blood supply to the pharynx is external carotid artery, giving off large trunks that feed the organs of the oral cavity and pharynx ( internal maxillary, lingual and internal facial arteries). The terminal branches of these arteries are: superior pharyngeal artery, supplying blood to the upper parts of the pharynx; ascending palatal which supplies blood curtain of palate, tonsil and auditory tube; descending palatine artery, supplying blood to the vault of the oral cavity; pterygopalatine arteries And arteries of the pterygopalatine node, supplying the walls of the pharynx and the auditory tube; posterior lingual, nourishes the mucous membrane, lingual tonsil, epiglottis and anterior palatine arch.

The palatine tonsils are supplied with blood from four sources: the lingual, superior pharyngeal and two palatine arteries. Often, the vessels feeding the palatine tonsils enter its parenchyma through the pseudocapsule not in the form of small branches that quickly thrombose when ruptured, but as one or more larger stems that branch in the tonsil after penetration into it. Such branches are difficult to thrombose during tonsillectomy and require special techniques to stop bleeding. The lower part of the pharynx is supplied by branches superior thyroid artery.

Veins of the pharynx form two plexuses that collect blood from almost all its parts. External, or peripheral, plexus is located mainly on the outer surface of the posterior and lateral walls of the pharynx. It is connected by numerous anastomoses to the second venous plexus - submucosal- and anastomoses with the veins of the palate, deep muscles of the neck and with the vertebral venous plexus. The pharyngeal veins, descending along the lateral walls of the pharynx, accompany the descending pharyngeal arteries and flow into the internal jugular vein or flow into one of its branches (lingual, superior thyroid, facial).

Lymphatic system The pharynx has an extremely complex structure, which is due, on the one hand, to the abundant blood supply to this organ, and on the other, to the fact that the pharynx and esophagus are in the path of agents external environment requiring biological control to exclude or stop harmful factors. In this regard, the most important role belongs to the solitary lymphoid accumulations of the pharynx, forming two “rings” (Fig. 3).

Rice. 3. Diagram of solitary lymphoid formations of the pharynx: outer ring: 1 - retropharyngeal lymph nodes; 2 - stylomastoid lymph nodes; 3 - lymph nodes of the lateral wall of the pharynx; 4 - retromastoid nodes at the site of attachment of the sternocleidomastoid muscle; 5 - nodes of the bifurcation of the common carotid artery; 6 - presternal-mastoid nodes; 7 - submandibular lymph nodes; 8 - jugular-hyoid lymph nodes; 9 - sublingual lymph nodes; inner ring: 10 - palatine tonsils; 11 - pharyngeal tonsil; 12 - lingual tonsil; 13 - tubar tonsils

Outer ring includes numerous lymph nodes of the neck (1-9). In inner ring(Pirogov-Waldeyer ring) includes the pharyngeal (11), tubal (13), palatine (10) and lingual (12) tonsils, lateral ridges of the pharynx and granules of its posterior wall.

Palatine tonsils consist of stroma and parenchyma (Fig. 4).

Rice. 4. Palatine tonsil (tonsilla palatina), right, horizontal section, top view (according to I. Dmitrienko, 1998): 1 - tonsil sinus; 2 - pharyngeal-palatal arch; 3 - crypts (lacunae); 4 - lymph nodes; 5 - glossopharyngeal arch; 6 - oral mucosa; 7 - mucous glands; 8 - bundles of connective tissue; 9 - lymphoid tissue; 10 - superior pharyngeal constrictor muscle

The stroma is a connective tissue bundle (8), fan-shaped diverging from the connective membrane covering the tonsil on the lateral side, dividing the tonsil parenchyma into lobules, the number of which can reach 20. The cells of the reticular tissue have phagocytic properties and actively absorb various types of inclusions (tissue decay products, bacteria and foreign particles) penetrating in abundance into the lacunar apparatus of the tonsils (3). The palatine tonsils branch with their lobules in niches that differ in different topographical positions (Fig. 5) and have important clinical significance.

Rice. 5. Schemes of variants of the niches of the palatine tonsils (according to Escat E., 1908): a - tonsil fossa of normal shape; b - the niche of the tonsil is located upward and into the thickness of the soft palate (sinus tortualis); c — pseudoatrophic form of the tonsil with its actual location in the sinus tortualis; 1 - soft palate; 2, 3 - palatal recess (sinus tortualis); 4 - internal segment of the tonsil; 5 - main segment of the tonsil

Pharyngeal tonsil is part of the unified system of the Pirogov-Waldeyer lymphadenoid ring. Its function includes the biological protection of the main sinus, ethmoidal labyrinth and auditory tubes. In addition, this amygdala is an immunobiological outpost of the structures of the base of the skull. The lymphadenbid apparatus of the nasopharynx, which also includes tubar tonsils, reacts to nasal mucus inclusions with the same immune reactions as the palatine tonsils. Its protective role is especially pronounced in childhood, in which this amygdala is well developed. Starting from the age of 12, the tubular tonsils undergo a process of reverse development and by the age of 16-20 they almost completely atrophy.

Innervation of the pharynx

The pharynx is innervated pharyngeal nerve plexus, which is formed by numerous anastomoses between the branches vagus, glossopharyngeal, accessory And sympathetic nerves. In addition, they take part in the innervation of individual anatomical formations of the pharyngoesophageal system. trigeminal, hypoglossal, superior laryngeal nerves, parasympathetic(secretory), sympathetic(trophic) and sensitive(flavor) fibers facial nerve . Such abundant innervation of the pharynx is due to the extreme complexity and diversity of its functions. Autonomic innervation has great value to ensure the functions of the pharynx, this innervation is actually integral with autonomic innervation esophagus. Sympathetic innervation the pharynx and esophagus are carried out through the cervical part borderline simatic trunks.

Physiology of the pharynx

The principle of anatomical and functional systematicity of the body allows us to consider the pharyngoesophageal system as a single functional organization consisting of interacting complexes. These complexes include chewing, swallowing (esophageal), air-conducting, resonator, gustatory, and protective. The latter complex includes mechanical and immunobiological defense systems. The functions of the above complexes are strictly synchronized in the implementation of both somatic and vegetative and immunobiological reactions. The loss of any of these functions leads to a mismatch in the mechanisms of their interaction.

Chewing complex

This complex includes, in addition to the chewing system of the jaws, also salivary glands, glands of the mucous membrane of the oral cavity and pharynx, tongue, palatine tonsils, etc. The chewing complex has direct relation to the physiology of the pharynx, since it is the first and main link that prepares food product to enter the digestive tract.

Swallowing and mechanoprotective complexes

These complexes ensure the advancement of the food bolus into the lumen of the esophagus. When the swallowing reflex occurs, a reflex contraction of the muscles of the soft palate and pharynx occurs, which ensures hermetic isolation of the middle part of the pharynx from the nasopharynx and prevents food from entering the latter ( first phase protective function of the pharynx).

At the moment the bolus of food moves into the pharyngeal cavity, a phase of protective function occurs, during which the larynx rises. In this case, the entrance to it is located above the food bolus, and the epiglottis, like a valve, descends and closes the entrance to the larynx. The muscles attached to the arytenoid cartilages bring the latter together and close the vocal folds, blocking the entrance to the subglottic space. When a bolus of food enters the esophagus, breathing is interrupted. Next, by successive contraction of the middle, then the lower pharyngeal constrictor, the food bolus or swallowed liquid enters the retrolaryngeal part of the pharynx. The contact of the food bolus with the receptors of this part of the pharynx leads to a reflex relaxation of the muscles at the entrance to the esophagus, as a result of which a gaping space is formed under the food bolus, into which the food bolus is pushed by the lower pharyngeal constrictor. Normally, the return of the food bolus from the hypopharynx to the oropharynx is impossible due to the continued pressing of the tongue against the palate and the posterior wall of the pharynx. The whole process of the act of swallowing and alternating it with respiratory function V. I. Voyachek figuratively called the larynx “the mechanism of the railway switch.”

Resonator and articulatory functions of the pharynx

The resonator and articulatory functions of the pharynx play an important role in the formation of vocal sounds and articulatory elements of speech, and take part in the individualization of the timbre characteristics of the voice. Pathological conditions pharynx (volumetric and inflammatory processes, disruption of innervation and trophism) lead to distortion of normal vocal sounds. Thus, obstructive processes in the nasopharynx, which impede or completely block the passage of sound into the nasal resonators, cause the occurrence of the so-called closed twang(rhinolalia clausa). And on the contrary, the gaping of the nasopharynx and the impossibility of its separation from the oropharynx due to the loss of the obturator function of the soft palate, palatine arches and the constrictor medialis of the pharynx lead to the fact that speech also becomes nasal and is characterized as open twang(rhinolalia operta). This voice is observed in patients after infiltration anesthesia before surgery to remove the palatine tonsils.

Immunobiological complex

When encountering factors of an antigenic nature in the alimentary and airways, the lymphadenoid apparatus of the pharynx exposes them to specific effects and thereby deprives them of their pathogenic properties. This process is called local immunity. Factors that stimulate immune processes in the body are called antigens.

There is an opinion about another function of the palatine and nasopharyngeal tonsils, according to which these lymphadenoid formations, being embryologically associated with the pituitary gland and thyroid gland, in early childhood play the role of endocrine glands, taking part in the development child's body. By the age of 7, this function is gradually reduced, but to date no convincing evidence has been found to support this opinion.

Taste organ

The taste organ is one of the five senses, causing the sensation of taste when specialized chemoreceptors on the tongue and oral cavity come into contact with flavoring substances. These chemoreceptors are represented by the so-called taste buds(taste buds). Sensory nerves approach the taste buds, through which impulses are transmitted to the taste centers brain stem(By drum string, innervating the anterior 2/3 of the tongue, and glossopharyngeal nerve, which provides the posterior third of the tongue with taste sensitivity). Taste buds are present in much smaller quantities on the back wall of the pharynx, soft palate and in the oral cavity.

Theories of taste. The theories of Yu. Rehnquist (1919) and P. P. Lazarev (1920) deserve the greatest attention. Rehnquist believed that taste perception is carried out due to the chemical effect of substances dissolved in water on the protoplasm of taste cells and nerve endings, and the main role in the occurrence of the taste sensation was attributed to the phenomenon of adsorption and the formation of a potential difference between the protoplasm of the cell and its environment. Regardless of Rehnquist, P. P. Lazarev put forward the concept according to which taste sensation arises as a result of the occurrence of a potential difference at the boundary of the taste cell shell. These potentials are based on ions of highly sensitive protein substances contained in taste glomeruli and disintegrate upon contact with the taste substance.

Otorhinolaryngology. V.I. Babiyak, M.I. Govorun, Ya.A. Nakatis, A.N. Pashchinin

The anatomy of the human pharynx is designed in a special way in order to perform the functions of breathing and digestion. It is in this section that the intersection of these paths occurs, but its structure allows food to penetrate only into the esophagus, and air into the respiratory organs.

The structure of the nasopharynx is designed in such a way that during swallowing movements the airways are open, but when a bolus of food moves through the esophagus, they are blocked by the muscles of the larynx. These mechanisms prevent food from entering the breathing hole.

The pharynx is considered as an entry gate for a variety of microorganisms, including pathogenic ones. Thanks to the fact that her inner surface contains an accumulation of lymphoid tissue, which is an integral part of the immune system; pathogenic microflora are captured and neutralized here.

The location of the pharynx in relation to other organs:

• in front - connection with the larynx and transition to the oral cavity, bypassing the pharynx;
• at the top – communication through the choanae (respiratory passages) with the internal nasal cavity;
• on the sides - connection with the middle ear cavity through the Eustachian canal;
• below - passes into the esophagus.

STRUCTURE OF THE HUMAN PHARYN

When considering the anatomical features of the pharynx, its 3 main sections are distinguished.

Main departments:

• The nasopharynx, or upper nasal section. Located above the palate at the same level with the first and second vertebrae of the neck, its communication with the nasal cavity occurs through the choanae. Through the openings of the Eustachian tube, located at the level of the lower nasal passage in the pharynx, there is a relationship with the internal tympanic cavity of the ear. This anatomical feature allows you to equalize the pressure in both cavities and ventilate the latter. For this reason, nasal breathing is important not only for the respiratory system, but also for auditory function. Between the soft palate and the exit of the Eustachian meatus there is a concentration of lymphoid tissue in the form of tonsils. They are represented by pairs of palatine and tubal tonsils, as well as adenoid and lingual tonsils. Their accumulation forms a kind of lymphatic ring, which is called the Pirogov-Waldeyer ring. Overgrowth, or hypertrophy, of the pharyngeal tonsil can cause choanae, or the openings of the auditory tubes, to become blocked, causing symptoms of difficulty breathing and dysfunction of the eustachian meatus in children under 14 years of age. In adulthood, the pharyngeal tonsil atrophies, and such a problem can no longer arise. The boundary between the upper and middle sections is arbitrary; the division occurs when a line is drawn back regarding the hard palate.
• The oropharynx is the oral or middle part. Includes the area from the palate to the larynx. The connection with the oral cavity occurs through the pharynx. The pharynx is covered from above by the palate and the uvula, and from below it is limited by the root of the tongue. On either side of the pharynx are the palatine arches. The oropharynx is formed by a posterior and two lateral walls. This is where the intersection of the respiratory tract and the digestive tract is located. The structure of the pharynx in this area has features that allow the soft palate to rise during swallowing and pronouncing sounds. Thus, the nasopharynx is isolated when performing the listed actions. The wall of the pharynx can be seen with the mouth wide open.
• The laryngopharynx is the laryngeal, or lower part. A narrow passage located behind the larynx. Here there is a front, two side and back walls. While at rest, the front and rear walls are closed to each other. The anterior wall forms a protrusion, above which the entrance to the larynx is located.

The pharynx has the shape of a funnel, flattened in the anteroposterior direction, the wide end of which originates at the base of the skull, then reaches the level of the 6–7 vertebrae of the neck, narrows and continues with the esophagus. On average, the length of the organ is about 12-14 cm, its internal space is formed by the pharyngeal cavity. The middle and upper parts are connected to the oral cavity, and the lower part is connected to the larynx.

The wall of the organ consists of muscles, connective tissue and mucous membranes. The latter is represented by multinucleated ciliated epithelium in its nasal part and is a continuation of the membranes of the oral and nasal cavities. The integumentary layer of other surfaces is lined with stratified squamous non-keratinizing epithelium, which fuses tightly with the muscle layer. Between the muscle layer and the mucous membranes there is a submucosal layer, represented by fibrous tissue. Connective tissue inclusions can be found in the buccal muscle and in the tissue of the esophagus.

Muscles of the pharynx:

• stylopharyngeal – controlled by consciousness, raises the larynx and pharynx;
• compressor muscles (upper, middle, lower) - narrow the lumen of the pharynx.

The alternating work of these muscle groups helps the passage of food lower towards the esophagus.

SWALLOWING PROCESS

The special structure and functions of the pharynx allow it to perform swallowing movements. The swallowing process occurs reflexively through tension and relaxation. different groups muscles.

Swallowing process:

• In the mouth, food is mixed with saliva and thoroughly crushed. A homogeneous lump is formed from it, which then falls on the area of ​​the root of the tongue.
• At the root of the tongue there is a group of sensitive receptors, the irritation of which provokes muscle contraction, due to which the palate rises. At the same moment, the connection between the pharynx and the nasal cavity is blocked and food does not penetrate the airways.
• The lump of food is pushed into the pharynx using the tongue. Here the muscles displace the hyoid bone, which causes the larynx to rise and the epiglottis to close the airway.
• In the pharynx, with the help of alternating contractions of different muscle groups, the gradual passage of food towards the esophagus is ensured.

FUNCTIONS OF THE PHARYN

The pharynx performs functions related to the life support of the body and its protection.

Main functions:

• Esophageal - provides swallowing and sucking movements due to the contractile work of the muscles. This process is an unconditional reflex act.
• Breathing is ensured by all parts of the organ, since air enters through them from the nasal and oral cavities into the lower respiratory tract. This process is made possible by the connection of the pharynx with the larynx, choanae and pharynx.
• Voice formation involves the creation and reproduction of sounds, the formation of which is provided inside the larynx vocal cords. When pronouncing sounds, the tongue and soft palate close and open the entrance to the nasopharynx, which ensures the timbre and pitch of sounds. The human pharynx acts as a kind of resonator due to its ability to narrow and expand.
• Protective – the lymphoid ring, together with other organs of the immune system, provides protection to the body from pathogens. The surface of the tonsils is dotted with grooves - lacunae, on the surface of which the infection is neutralized. In addition, when the ciliated epithelium on the mucosal surface is irritated, muscle contraction occurs, the lumen of the pharynx narrows, mucus is released and a cough begins, which acts as a protective reaction of the body.

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The pharynx is located in front of the cervical spine and between the large vessels and nerve trunks of the neck. It is a cavity with muscular walls covered with mucous membrane.

The pharynx is divided into 3 sections: upper - nasopharynx; middle - oral, or middle, part of the pharynx (oropharynx) and lower - laryngeal part pharynx, or hypopharynx.

The upper part of the pharynx - the nasopharynx - is located behind the choanae, and its arch is the base of the skull. On the posterior wall of the nasopharynx there are accumulations of lymphoid tissue that form the nasopharyngeal tonsil. In children, the nasopharyngeal tonsil usually increases in volume and is known as “adenoids”. On the lateral walls of the nasopharynx there are pharyngeal openings of the Eustachian tubes, through which communications are established between the nasopharynx and the cavities of the middle ear.

The middle part of the pharynx - the oropharynx - communicates with the oral cavity through the pharynx. The pharynx is limited above by the soft palate, below by the root of the tongue and on the sides by the anterior and posterior arches and the palatine tonsils located between them.

The lower part of the pharynx, or laryngopharynx, is located in front of the IV, V and VI cervical vertebrae, tapering downwards in the form of a funnel. The so-called entrance to the larynx protrudes into the lumen of its lower part, on the sides of which pear-shaped pits are formed. Connecting behind the plate of the cricoid cartilage, they pass into the initial part of the esophagus. On the anterior wall of the lower part of the pharynx, formed by the root of the tongue, is the lingual tonsil.

Accumulations of lymphadenoid tissue located in various parts of the pharynx play an important role in the physiology and pathology of the human body.

In the human pharynx there are the following largest lymphadenoid formations, named according to their location: two palatine tonsils (Fig. 25) (right and left), nasopharyngeal and lingual tonsils; There are also accumulations of lymphadenoid tissue, which, starting in the nasopharynx, spread downwards from both sides in the form of the so-called lateral pharyngeal ridges. Lymphadenoid formations in the area of ​​the pharyngeal openings of the Eustachian tubes are known as tubal tonsils. The same kind of formations are often found in the mucous membrane of the posterior wall of the pharynx in the form of scattered grains (granules), as well as in the pyriform fossae and in the thickness of the false vocal cords.

Rice. 25. Throat.
1 - posterior wall of the pharynx; 2 - small tongue; 3 - palatine tonsil; 4, 5 and 6 - palatine arches; 7 - soft palate.

Both palatine tonsils, nasopharyngeal and lingual tonsils, along with those scattered in various departments The pharynx lymphadenoid formations make up the Pirogov-Waldeyer pharyngeal lymphadenoid ring.

The palatine tonsils are oval-shaped structures located on the side walls of the pharynx, in the niches between the anterior and posterior arches.

The tonsils have two surfaces: external and internal. The outer (lateral) surface of the tonsil is adjacent to the side wall of the pharynx, covered with a connective tissue capsule through which vessels pass: connective tissue septa extend from the capsule, between which lymphoid tissue (tonsil parenchyma) is laid. Between the tonsil capsule and the muscular layer of the lateral wall of the pharynx there is loose peritonsillar tissue.

On the free inner surface of the tonsils, covered with mucous membrane, in many places there are visible holes leading into deep pockets (tonsil crypts, or lacunae). Crypts are not visible, but hidden in the depths. That is why they are called crypts (from Greek word cryptos - hidden). Even healthy people have contents in the lacunae. Plugs can form in them, consisting of small particles of food, microbes, desquamated epithelial cells, mucus, etc. Each tonsil can have up to 12-15 lacunae, which sometimes turn out to be branching. In such cases, spontaneous emptying of lacunae during talking, swallowing, coughing, etc. usually occurs easily. Often, however, tonsil lacunae have the shape of flasks or tree-like branched passages with narrow outlet openings. These holes can be located on the surface of the tonsils and in the supramyngdal fossa. The presence of free space in the supramidal area promotes the accumulation of secretions and creates favorable conditions for development pathological process.

The size of the palatine tonsils varies not only among different people, but also at different periods of the life of the same person.

Normally, the palatine tonsils are clearly visible during pharyngoscopy; they protrude somewhat from the edges of the front arches and completely or partially cover the edges of the rear arches.

In some people, the tonsils are so small or located so deep in the niches that they are difficult to see when examining the pharynx. In others, on the contrary, giant tonsils are sometimes observed.

To symbolize the degree of enlargement of the palatine tonsils, B. S. Preobrazhensky suggests mentally dividing the distance between the middle of the free edge of the anterior arch and the midline of the body into three parts; if the tonsil reaches the midline, then this is an increase in the tonsil of the third degree, if the tonsil occupies the lateral 2/3 of the indicated distance, then this is an increase in the second degree, and if only one third - an increase in the first degree.

Enlargement of the palatine tonsils does not always indicate the presence of an acute or chronic disease. Not all people who have enlarged tonsils suffer from tonsillitis or chronic tonsillitis.

Enlargement of the palatine tonsils, characteristic of children, should be regarded as pathological phenomenon only in cases where they reach such a size that they cause disruption of swallowing, respiratory and speech functions.

As the data shows histological examination, the parenchyma of the tonsils consists of reticular tissue, in the loops of which lymphocytes and lymphoblasts originating from the same tissue are located. The lymphatic tissue is interspersed with denser spherical formations - follicles. The latter on the section appear lighter in the middle (germinal or reactive centers) and darker at the edges.

Along with lymphocytes, which make up the majority of the cellular elements of the tonsil apparatus, reticular tissue can also produce monocytes, macrophages, and plasma cells involved in immunogenesis.

The tonsils, like all the walls of the mouth and pharynx, are covered with a mucous membrane. Normally, the color of the tonsils is similar to the color of the mucous membrane of the cheeks, hard and soft palate and the back wall of the pharynx.

At the same time, the color of the pharyngeal mucosa is very individual; from different people and even from the same person in different times it may not be the same. In some people this coloring is bright, in others it is pale. In addition, the periodic appearance of hyperemia of the pharynx can also be observed in people, depending on the nature of the regulation of the lumen of blood vessels (vasomotor disorders, according to V.I. Voyachek).

From other lymphadenoid formations pharyngeal ring The nasopharyngeal tonsil is important, especially for the child’s body. In children, it is often enlarged and is known as adenoids, or adenoid vegetations (growths). From approximately 9-12 years of age, it begins to decrease in size (subject to involution).

The growth of the nasopharyngeal tonsil usually occurs unnoticed, more often after infectious diseases (measles, scarlet fever, influenza, whooping cough, etc.). Adenoids are not only a mechanical obstacle to nasal breathing, but also lead to circulatory problems, namely: they cause congestion in the nose and swelling of the nasal mucosa.

The folds of adenoid growths contain microbes that can cause acute and chronic diseases of the nasopharynx. Children with adenoids often get colds, flu, catarrh of the upper respiratory tract and sore throat. These children often develop chronic tonsillitis.

The lymphadenoid ring of the pharynx, like the entire pharynx, is supplied with blood from the arterial vessels of the external carotid artery system. Venous and lymphatic vessels form a dense network, especially in places where lymphadenoid tissue of the pharynx accumulates. The draining lymphatic vessels are directed to the lymph nodes of the retropharyngeal space and to the upper cervical deep lymph nodes located on the lateral surface of the neck at the junction of the common facial and internal jugular veins. With tonsillitis and chronic tonsillitis, the lymph nodes become enlarged, and then they can be felt by palpating the lateral surfaces of the neck.

The pharynx is innervated by three cranial nerves (glossopharyngeal, recurrent, accessory) and sympathetic.