Pharynx, pharynx, is the initial part of the digestive tube and respiratory tract. The pharyngeal cavity, cavum pharyngis, connects the oral and nasal cavities with the esophagus and larynx. In addition, it communicates through the auditory tube with the middle ear. The pharynx is located behind the cavities of the mouth, nose and larynx, extending from the base of the skull, from which it begins, to the junction with the esophagus at the level of the VI cervical vertebra. The pharynx is a hollow, wide tube, flattened in the anteroposterior direction, narrowing as it passes into the esophagus. The pharynx can be divided into upper, anterior, posterior and lateral walls. The length of the pharynx is on average 12-14 cm.

Depending on the organs behind which the pharynx is located, three parts are distinguished: 1) nasal, pars nasalis (or nasopharynx), 2) oral, pars oralis (or oropharynx), 3) laryngeal, pars laryngea (or hypopharynx). The upper part of the pharynx, adjacent to the outer base of the skull, is called the pharyngeal vault, fornix pharyngis.

Nasal part of the pharynx , pars nasalis pharyngis, is its upper part and differs from other parts in that the upper and partially lateral walls are fixed to the bones and therefore do not collapse. The anterior wall of the pharynx is absent here, since in front the nasopharynx communicates with the nasal cavity through two choanae. On the lateral walls of the nasal part of the pharynx, at the level of the posterior end of the inferior concha, there is a paired funnel-shaped pharyngeal opening auditory tube, ostium pharyngeum tubae, which is bounded behind and above by a tubular ridge, torus tubarius. This cushion is formed due to the protrusion of the cartilage of the auditory tube into the pharyngeal cavity. A short tubal-pharyngeal fold of the mucous membrane, plica salpingopharyngea, descends from the tubal ridge. Behind the cushion, the mucous membrane forms a large pharyngeal pocket, variable in shape, recessus pharyngeus, the depth of which depends on the degree of development of the tubal tonsils. At the junction of the upper wall and the posterior wall between the pharyngeal openings of the auditory tubes in the mucous membrane of the pharynx there is an accumulation of lymphoid tissue - the pharyngeal tonsil, tonsilla pharyngea. In children it is most developed, but in adults it undergoes reverse development. The second, paired, accumulation of lymphoid tissue lies in the mucous membrane of the pharynx in front of the pharyngeal openings of the auditory tubes. It is called the tubal tonsil, tonsilla tubaria. Together with the palatine, lingual, and laryngeal lymphatic follicles, the pharyngeal and tubal tonsils make up the lymphoepithelial pharyngeal ring. On the vault of the pharynx in the midline near the junction of the upper wall and the posterior wall there is sometimes a round depression - the pharyngeal bursa, bursa pharyngea.

Oropharynx , pars oralis pharyngis, occupies the level from the soft palate to the entrance to the larynx, widely communicating through the pharynx with the oral cavity. Therefore, the oral part has only lateral and posterior walls; the latter corresponds to the third cervical vertebra. The oral part of the pharynx functionally belongs to both the digestive and respiratory systems, which is explained by the development of the pharynx (see section The doctrine of the viscera - splanchnology, this edition). When swallowing, the soft palate, moving horizontally, isolates the nasopharynx from its oral part, and the root of the tongue and the epiglottis close the entrance to the larynx. When wide open mouth the posterior wall of the pharynx is visible.

Laryngeal part of the pharynx , pars laryngea pharyngis, is located behind the larynx at the level from the entrance to the larynx to the beginning of the esophagus. It has front, back and side walls. Outside of the act of swallowing, the anterior and posterior walls are in contact. The anterior wall of the laryngeal part of the pharynx is the laryngeal protrusion, prominentia pharyngea, above which is the entrance to the larynx. On the sides of the protrusion there are deep pits - pear-shaped pockets, recessus piriformes, formed on the medial side by the laryngeal protrusion, and on the lateral side by the lateral wall of the pharynx and the posterior edges of the plates of the thyroid cartilage. The pear-shaped pocket is divided by an oblique fold laryngeal nerve, plica nervi laryngei, into two sections - the smaller one is the upper one, and the larger one is the lower one. The superior laryngeal nerve passes through the fold.

The nasopharynx of newborns is very small and short. The vault of the pharynx is flattened and inclined anteriorly in relation to its oral part. In addition, in newborns the pharynx is relatively shorter than in adults, and the velum palatine is in contact with the entrance to the larynx. The soft palate is short and does not reach the posterior wall of the pharynx when raised. In the first years of life, the tonsils protrude strongly into the pharyngeal cavity of newborns and children. The pharyngeal openings of the auditory tubes are close together and lie lower than in adults, at the level of the hard palate. The pharyngeal pockets, as well as the tubal ridges and tubopalatine folds, are weakly expressed.

Structure of the pharynx . The pharynx consists of: 1) the mucous membrane, 2) the fibrous layer formed by the pharyngeal-basic fascia, 3) the muscular layer, 4) the buccal-pharyngeal fascia covering it.

Mucous membrane The nasal part of the pharynx is covered with multi-row ciliated epithelium, and the oral and laryngeal parts are covered with multi-layered squamous epithelium. In the submucosa there is a large number of mixed (muco-serous - in the nasopharynx) and mucous (in the oral and laryngeal parts) glands, the ducts of which open into the pharyngeal cavity on the surface of the epithelium. In addition, the submucosal layer contains clusters of lymphatic follicles that form the pharyngeal and tubal tonsils. There are many small glands between the follicles mixed type. At the location of the pharyngeal tonsil, the mucous membrane gives off spurs into the thickness of the tonsil, forming a series of folds and dimples, fossulae tonsillares. In the dimples of the pharyngeal tonsil there are depressions - tonsil crypts, cryptae tonsillares, into which the ducts of the mixed glands located between the lymphatic follicles open.

The submucosa is well expressed, and the layer proper tunicae mucosae contains many elastic fibers. As a result, the mucous membrane has the ability to change its size as food passes through. Near the junction with the esophagus, the pharynx narrows. In its narrow section, the mucous membrane is smooth and contains especially many elastic fibers, which ensures the passage of the food bolus here.

Pharyngeal-basic fascia , fascia pharyngobasilaris, forms the fibrous basis of the pharynx. The pharyngeal-basic fascia begins on the outer base of the skull on the pharyngeal tubercle occipital bone and runs on each side transversely along a curved line anteriorly from the place of attachment of the deep layer of the anterior muscles of the neck along the main part of this bone to the synchondrosis retrooccipitalis. Next, the line of the beginning of the fascia turns anteriorly and outward, crosses the pyramid of the temporal bone anteriorly from the foramen caroticum externum and follows to the spina ossis sphenoidalis. From here the line of origin of the fascia deviates forward and medially and runs along the synchondrosis sphenopetrosa in front of the cartilage of the auditory tube to the base of the medial plate of the pterygoid process sphenoid bone. Then it follows the medial plate of the process down and anteriorly along the raphe pterygomandibularis to the posterior edge of the linea mylohyoidea mandibulae.

In the upper section, the pharyngeal-basic fascia is very strong, since here it is strengthened by bundles of collagen fibers that go into the fascia in the form of ligaments from the pharyngeal tubercle, from the edge of the foramen caroticum externum and from the membranous plate of the auditory tube. In addition to collagen bundles, the pharyngeal-basic fascia contains many elastic fibers. Below, the pharyngeal-basic fascia is attached to the thyroid cartilage and the greater horns of the hyoid bone, giving off spurs into folds: plicae pharyngoepiglotticae and plicae epiglotticae.

Muscular membrane of the pharynx , tunica muscularis pharyngis, consists of two groups of striated muscles: compressors, constrictores pharyngis, located circularly, P I levators, levatores pharyngis, running longitudinally. The pharyngeal constrictor muscles, paired formations, include the upper, middle and lower constrictors (Fig. 113).

Rice. 113. Muscles of the pharynx (rear view). 1 - posterior belly of the digastric muscle; 2, 8, 14 - stylopharyngeal muscle; 3 - stylohyoid muscle; 4 - medial pterygoid muscle; 5, 13 - middle pharyngeal constrictor; c - hyoid bone; 7, 10 - upper and lower horns of the thyroid cartilage; 11 - esophagus; 12 - lower pharyngeal constrictor; 15, 17 - superior pharyngeal constrictor; 16 - styloid process; 18 - main part of the occipital bone; 9, 19 - pharyngeal suture; 20 - fibrous membrane of the pharynx

1.Muscle - superior pharyngeal constrictor, m. constrictor pharyngis superior, starts from laminae medialis processus pterygoidei (pterygopharyngeal part of the muscle, pars pterygopharyngea), raphe pterygomandibulare (buccopharyngeal part, pars buccopharyngea), linea mylohyoidea mandibulae (maxillopharyngeal part, pars mylopharyngea) and the transverse muscle of the tongue ( glossopharyngeal part, pars glossopharyngea). Starting on the listed formations, the muscle bundles form the lateral wall of the pharynx, and then arc in an arcuate direction posteriorly and medially, forming the posterior wall. Posteriorly along the midline, they meet the bundles of the opposite side at the tendon pharyngeal suture, raphe pharyngis, running from the tnberculum pharyngeum along the middle of the entire posterior wall to the esophagus. The upper edge of the muscle - the superior constrictor of the pharynx does not reach the base of the skull. Therefore, in the upper section (over 4-5 cm), the wall of the pharynx is devoid of a muscular membrane and is formed only by the pharyngeal-basal fascia and mucous membrane.

2.Muscle - middle pharyngeal constrictor, m. constrictor pharyngis medius, starts from the upper part of the greater horn of the hyoid bone (horns of the opharyngeal part of the muscle, pars ceratopharyngea) and from the lesser horn and lig. stylohyoideum (cartilaginous-pharyngeal part, pars chondropharyngea). The upper muscle bundles go upward, partially covering the superior pharyngeal constrictor (when viewed from behind), the middle bundles go horizontally backward (almost completely covered by the lower constrictor) and the lower ones go down (completely covered by the lower constrictor). The bundles of all parts end in raphe pharyngis. Between the middle and superior constrictors are the lower bundles of the stylopharyngeal muscle.

3.Muscle - inferior pharyngeal constrictor, m. constrictor pharyngis inferior, starts from the outer surface of the cricoid cartilage (cricopharyngeal part of the muscle, pars cricopharyngea), from the oblique line and the adjacent parts of the thyroid cartilage and from the ligaments between these cartilages (thyropharyngeal part, pars thyreopharyngea). The muscle bundles run posteriorly in ascending, horizontal and descending directions, ending at the suture of the pharynx. The lowest bundles surround the junction of the pharynx and the esophagus. The upper constrictor is the largest, covering the lower half of the middle constrictor.

Function: they narrow the pharyngeal cavity and, with successive contractions, push through the bolus of food.

The muscles that elevate and dilate the pharynx include:

1.Stylopharyngeal muscle, m. stylopharyngeus, originates from the styloid process near its root, goes down and medially to the posterolateral surface of the pharynx, penetrating between its superior and middle constrictors. The muscle fibers, partially intertwined with the lower and middle constrictors, go to the edges of the epiglottis and thyroid cartilage.

Function: raises and expands the pharynx.

2.Velopharyngeal muscle, m. palatopharyngeus, see section The oral cavity itself, this publication.

The buccal-pharyngeal fascia covers the external constrictor muscles. Since the buccal muscle has a superior constrictor common place beginning (raphe pterygomandibulare), fascia with m. The buccinator moves to the upper and then to other pharyngeal constrictors.

Syntopy of the pharynx. Behind the pharynx are the long muscles of the neck (mm. longus capitis and longus colli) and the bodies of the first cervical vertebrae. Here, between the buccal-pharyngeal fascia, which covers the outside of the pharynx, and the parietal leaf of the fasciae endocervicalis, there is an unpaired retropharyngeal space, spatium retropharyngeum, which is important as a possible location of retropharyngeal abscesses. On the sides of the pharynx there is a second, paired, cellular space - the peripharyngeal space, spatium parapharyngeum, limited medially by the lateral wall of the pharynx, laterally by the branch of the mandible, m. pterygoideus medialis and muscles starting on the styloid process behind - the anterior surface of the massa lateralis atlantis and lamina parietalis fasciae endocervicalis. The peripharyngeal space, in which the internal carotid artery and internal jugular vein are located, passes posteriorly into the retropharyngeal space.

Adjacent to the lateral surfaces of the laryngeal part of the pharynx are the upper poles of the thyroid gland and the common carotid arteries. In front of it is the larynx.

The blood supply to the pharynx is carried out from the external carotid artery system: the ascending pharyngeal (from a. carotis ext), the ascending palatine (from a. facialis) and the descending palatine (from a. maxillaris). The laryngeal part of the pharynx, in addition, receives branches from the superior thyroid artery: The intraorgan veins of the pharynx form venous plexuses in the submucosa and on the outer surface of the muscular layer, from where blood flows through the pharyngeal veins into the internal jugular vein or its tributaries.

Lymphatic vessels of the pharynx are formed from capillary networks, lying in all layers of the pharyngeal wall. The drainage collectors go to the retropharyngeal (partially to the facial) and mainly to the deep cervical lymph nodes.

CLINICAL ANATOMY OF THE PHARYNX

Pharynx represents the initial part of the digestive tube located between the oral cavity and the esophagus. At the same time, the pharynx is part of the respiratory tube through which air passes from the nasal cavity to the larynx.

The pharynx extends from the base of the skull to the level of the VI cervical vertebra, where it narrows into the esophagus. The length of the pharynx in an adult is 12-14 cm and is located anterior to the cervical spine.

The pharynx can be divided into upper, posterior, anterior and lateral walls.

Upper wall of the pharynx- vault (fornixpharyngis)- attaches to the outer surface of the base of the skull in the region of the basilar part of the occipital bone and the body of the sphenoid bone.

Posterior wall of the pharynx adjacent to prevertebral plate (laminaprevertebralis) cervical fascia and corresponds to the bodies of the five upper cervical vertebrae.

Lateral walls of the pharynx are located close to the internal and external carotid arteries, internal jugular vein, vagus, hypoglossal, glossopharyngeal nerves, sympathetic trunk, large horns of the hyoid bone and plates of the thyroid cartilage.

Anterior wall of the pharynx in the upper section in the area of ​​the nasopharynx it communicates with the nasal cavity through the choanae; in the middle section it communicates with the oral cavity.

There are three sections in the pharyngeal cavity (Fig. 3.1):

Upper – bow, or nasopharynx(pars nasalis, epipharynx);

Rice. 3.1. Sections of the pharynx: 1 – nasopharynx; 2 – oropharynx; 3 – laryngopharynx

Average - mouth part, or oropharynx(pars oralis, mesopharynx);

Lower – laryngeal part, or hypopharynx(pars laryngea, hypopharynx).

Nasopharynx (nasopharyngs, epipharyngs)- located from the vault of the pharynx to the level hard palate. Its anteroposterior size is often reduced due to the protrusion of the first cervical vertebra (Atlanta). Her front wall is occupied choanae, communicating it with the nasal cavity. On the side wall on each side at the level of the posterior ends of the inferior nasal conchae there are funnel-shaped pharyngeal openings of the auditory tube, connecting the pharynx with the tympanic cavity. At the top and back these openings are limited pipe rollers, formed by the protruding cartilaginous walls of the auditory tubes. Posterior to the tubal ridges and the mouth of the auditory tube, there is a depression on the lateral wall of the nasopharynx - pharyngeal pocket (fossa Rosenmulleri), in which there is an accumulation of lymphadenoid tissue. These lymphadenoid formations are called tubal tonsils. On the posterosuperior wall of the nasopharynx there is III, or pharyngeal (nasopharyngeal), tonsil. Hypertrophy of this amygdala (adenoid growths) can partially or completely cover the choanae, causing difficulty in nasal breathing, or the mouth of the auditory tubes, disrupting their function. The pharyngeal tonsil is well developed only in childhood; with age, after 14 years, it atrophies. The boundary between the upper and middle parts of the pharynx is the plane of the hard palate, mentally extended posteriorly.

Oropharynx (oropharyngs, mesopharyngs) extends from the level of the hard palate to the level of the entrance to the larynx. The posterior wall of this section corresponds to the body of the third cervical vertebra. In front, the oropharynx communicates with the oral cavity through the pharynx. Zev (fauces) limiting

from above soft palate below - root of the tongue and from the sides - palatine (anterior) And palatopharyngeal (posterior) arches.

Soft palate (palatum molle)- continuation of the hard palate, is a movable plate that hangs down to the base of the tongue in a calm state. The soft palate is formed mainly by muscles and aponeurosis of tendon bundles. Rear end soft palate, directed obliquely backwards and downwards, together with the root of the tongue limits the opening of the pharynx (isthmus faucium). The free end of the soft palate, elongated in the form of a process along the midline, is called uvula.

On each side, the velum palatine passes into two arches. One (front) goes to the root of the tongue - palatoglossus (arcus palatoglossus), the other (posterior) passes into the mucous membrane of the lateral wall of the pharynx - palatopharyngeus (arcus palatopharyngeus). From the posterior surface of the palatoglossus arch there extends a thin, pronounced to varying degree triangular fold mucous membrane (plica triangularis), or fold of His. Under the cover of the mucous membrane, the soft palate contains the aponeurotic plate, as well as a number of muscles that play important role in the act of swallowing:

*muscle that stretches the soft palate (m. tensor veli palatini), stretches the anterior section of the soft palate and the pharyngeal section of the auditory tube;

*muscle that lifts the velum palatini (m. levator veli palatini), raises the soft palate, narrows the lumen of the pharyngeal opening of the auditory tube;

*palatoglossus muscle (m. palatoglossus) located in the palatoglossus arch, attached to the lateral surface of the tongue and, when tense, narrows the pharynx, bringing the anterior arches closer to the root of the tongue;

palatopharyngeus muscle (m. palatopharyngeus) located in the palatopharyngeal arch, attached to the side wall of the pharynx, when tense, it brings the palatopharyngeal arches together and pulls up the lower part of the pharynx and larynx. Between the palatine arches on each side of the pharynx there is a triangular-shaped depression - tonsillar niche (tonsillar fossa or bay), (fossa tonsillaris), the bottom of which is formed by the superior pharyngeal constrictor and the pharyngeal fascia. The largest accumulations of lymphoid tissue are located in the tonsillar niches - I and II or palatine tonsils (tonsilae palatinae)(Fig. 3.2).

Rice. 3.2. Oropharynx: 1 – uvula; 2 – palatoglossus (anterior) arch; 3 – palatine tonsils; 4 – velopharyngeal (posterior) arch

Distinguish yawning(internal) and lateral(outer) surface of the palatine tonsils, its upper and lower poles. Yawn surface facing the pharyngeal cavity and contains 16-18 deep, tortuous canals called crypts, which penetrate the thickness of the amygdala and have branches of the first, second, third and even fourth order (Fig. 3.3). The external (pharyngeal) openings of the crypts look like depressions - gaps, in which small epidermal contents sometimes accumulate. The integumentary epithelium of the walls of the crypts of the tonsils is in contact with lymphoid tissue over a large area. The crypts are more developed in the area of ​​the upper pole of the tonsils; their lumen contains desquamated epithelium, lymphocytes, leukocytes, bacteria, and food debris. Lateral surface of the palatine tonsils covered with a dense fibrous connective tissue membrane called pseudocapsule(false capsule), the thickness of which reaches 1 mm. It is formed by the intersection of the plates of the cervical fascia. Connective tissue fibers extend from the pseudocapsule into the thickness of the tonsils - trabeculae. Trabeculae branch and form a densely looped network in the tonsil parenchyma, in which there is a mass of lymphocytes surrounding spherical accumulations varying degrees lymphocyte maturity, called follicles. In addition, there are other cells - mast cells, plasma cells. Between the lateral wall of the pharynx and the pseudocapsule of the tonsil is located paratonsillar tissue, more developed in the upper pole of the palatine tonsil. The pseudocapsule is absent in the lower pole and on the pharyngeal surface of the tonsil.

Rice. 3.3. Structure of the palatine tonsil:

1 – lacuna; 2 – follicle; 3 – connective tissue capsule (pseudocapsule); 4 – trabecula

In the area superior pole of the tonsil sometimes there is a triangular depression in which lymphoid formations are located - sine of Tourtoile, which may continue as an accessory lobe of the tonsil into the soft palate (Fig. 3.4). The great depth and tortuosity of the lacunae in the upper pole often contribute to the occurrence of an inflammatory process and foci of latent purulent infection. At a distance of about 2.8 cm from the upper pole of the tonsil is the internal carotid artery, and the external carotid artery is approximately 4.1 cm away.

Rice. 3.4. A lobe of the palatine tonsils located in the thickness of the soft palate (sinus of Tourtual)

Lower pole of the tonsil hangs over the root of the tongue, is tightly fused to the side wall and is relatively difficult to separate during tonsillectomy. From the lower pole of the tonsil, the internal carotid artery is located at a distance of 1.1-1.7 cm, and the external carotid artery is located at a distance of 2.3-3.3 cm. An important factor from the point of view of pathology is that the emptying of deep and tree-like branched crypts it is easily disrupted due to their narrowness, depth and branching, as well as due to cicatricial narrowing of the mouths of the crypts (lacunae), part of which in the anterior lower part of the palatine tonsil is covered by a fold of the mucous membrane - the fold of His.

These anatomical and topographical features of the palatine tonsils, along with the location of the palatine tonsils in the area of ​​​​the intersection of the esophageal and respiratory tracts, create favorable conditions for the occurrence of chronic inflammation in these tonsils.

It should be noted that the anatomical structure of the crypts, except for the palatine tonsils, is not presented anywhere else.

hypopharynx (laryngopharyngs, hypopharyngs)- begins at the level of the upper edge of the epiglottis and the root of the tongue, narrows downwards in the form of a funnel and passes into the esophagus. The hypopharynx lies posterior to the larynx and anterior to the IV, V and VI cervical vertebrae. This is the narrowest part of the pharynx. In the initial section of the laryngopharynx at the root of the tongue there is IV, or lingual tonsil(tonsilla lingvalis)(Fig. 3.5).

Rice. 3.5. Lingual tonsil: 1 – lingual tonsil; 2 – epiglottis; 3 – vocal fold; 4 – interarytenoid space, 5 – aryepiglottic fold, 6 – vestibular fold, 7 – valecula

Below the attachment of the epiglottis, the hypopharynx becomes the larynx. On the sides of the entrance to the larynx, between the wall of the larynx and the side walls of the pharynx, from top to bottom on the right and left there are cone-shaped narrowings of the pharynx, which are called pear-shaped pockets (recessus piriformis)- food is sent through them to the esophagus. The entrance to the larynx is limited in front by the epiglottis, and on the sides by the aryepiglottic folds.

The wall of the pharynx is formed by four membranes:

fibrous (tunica fibrosa);

connective tissue (tunica adventitia); muscular (tunica muscularis);

mucosa (tunica mucosa).

Between the muscular and mucous membranes there is a submucosal layer, characterized by the presence of fibrous tissue in it, which is why this layer is called fibrous membrane. On the outside, the muscles, in turn, are covered with a thinner connective tissue layer - adventitia, on which lies loose connective tissue, allowing the mobility of the pharynx in relation to the surrounding anatomical formations.

Mucous membrane The pharynx is a continuation of the mucous membrane of the nasal cavity and mouth and below passes into the mucous membrane of the larynx and esophagus. In the upper part of the pharynx near the choanae, the mucous membrane is covered with multirow ciliated epithelium, in the middle and lower parts - with flat multirow epithelium. The mucous membrane of the pharynx contains many mucous glands, and on the back wall there are small accumulations of lymphoid tissue in the form of tubercles on the mucous membrane measuring 1-2 mm - lymphoid granules. The mucous membrane here is tightly fused with the muscular layer and does not form folds.

Muscle layer pharynx consists of striated fibers and is represented by circular and longitudinal muscles, constricting and elevating the pharynx.

Three constrictors compress the pharynx: upper, middle and lower. These muscles are located from top to bottom in the form of plates, tiled-like covering each other.

Superior pharyngeal constrictor (m. constrictor pharyngis superior) has the shape of a quadrangular plate, starting in front of the sphenoid bone and lower jaw. The muscle bundles run horizontally along the side wall of the pharynx to the back and connect

with bundles of muscles on the opposite side, forming the upper part of the median suture of the pharynx.

Middle pharyngeal constrictor (m. constrictorpharyngis medius) starts from the horns of the hyoid bone, goes posteriorly in a fan-shaped manner to the suture of the pharynx, partially covering the superior constrictor, and below is located under the inferior constrictor.

Lower pharyngeal constrictor (m. constrictor pharyngis inferior) It starts from the outer surface of the cricoid cartilage, from the lower horn and the posterior edge of the thyroid cartilage, goes posteriorly and along the midline of the pharynx forms the pharyngeal suture with its attachment.

Longitudinal muscles raise the throat. These include two muscles: stylopharyngeus (m. stylopharyngeus) And palatopharyngeal (m. pharyngopalatinus).

The lateral and posterior walls of the pharynx border with peripharyngeal space (spatium parapharyngeum), in which they distinguish retropharyngeal space And lateral parapharyngeal space.

Retropharyngeum (spatium retropharyngeum)(Fig. 3.6) located anterior to the cervical vertebrae, the muscles covering them and the prevertebral plate of the cervical fascia; it

represents a narrow

a gap that is filled with loose connective tissue. This space in the back is limited prevertebral plate of the cervical fascia (lamina praevertebralis), in front - the connective tissue cover and mucous membrane, and on the sides - fascia and fiber - surrounding the area of ​​large vessels and nerves of the neck. Fiber is swallowed

Rice. 3.6. Retropharyngeal space:

1 – prevertebral plate of the cervical fascia; 2 – fiber of the retropharyngeal space

This space, starting from the base of the skull and going down the posterior wall of the pharynx, passes into the retroesophageal tissue and further into posterior mediastinum. Lateral parapharyngeal space (spatium lateropharyngeum)(Fig. 3.7) made of loose connective tissue, limited in front by the inner surface of the branch of the lower jaw, on the inside - by the medial pterygoid muscle, behind

Prevertebral plate of the cervical fascia, lateral

Deep layer of fascia of the parotid salivary gland. The lateral parapharyngeal space is divided by the stylopharyngeal muscle into the anterior and posterior sections. The lateral parapharyngeal space extends from the base of the skull downwards, where it passes into the mediastinum.

Blood supply to the pharynx carried out from the system of the external carotid artery and the thyrocervical trunk (Fig. 3.8).

Rice. 3.7. Lateral parapharyngeal space:

1 – medial pterygoid muscle; 2 – prevertebral plate of the cervical fascia; 3 – parotid gland; 4 – lower jaw; 5 – palatine tonsil

Rice. 3.8. Blood supply to the pharynx:

1 – descending palatine artery; 2 – maxillary artery; 3 – external carotid artery; 4 – common carotid artery; 5 – lingual artery; 6 – ascending palatine artery; 7 – facial artery; 8 – superior thyroid artery

Ascending pharyngeal artery (a. pharyngea ascendens)- the medial branch of the external carotid artery provides blood supply to the upper and middle parts of the pharynx.

Ascending palatine artery (a.palatina ascendens)- branch of the facial artery (a. facialis), which also originates from the external carotid artery.

Descending palatine artery (a. palatina descendens)- a branch of the maxillary artery, which is the terminal branch of the external carotid artery.

The lower parts of the pharynx are supplied with blood by the pharyngeal branches inferior thyroid artery (a. thyreoidea inferior) – branches of the thyrocervical trunk. The palatine tonsil supplies blood: ascending pharyngeal artery (a. pharyngea ascendens), ascending palatine artery (a. palatina ascendens) And tonsillar branch of the facial artery (r. tonsillaris a. facialis)(Fig. 3.8).

Veins of the pharynx form front And posterior pharyngeal plexus (plexus pharyngeus anterior et posterior), located in the soft palate and on the outer surface of the posterior and lateral walls of the pharynx, respectively, blood from them collects in internal jugular vein (v. jugularis interna).

Lymph drainage from the pharynx occurs in deep And posterior cervical lymph nodes. The retropharyngeal lymph nodes are divided into lateral and median, which are found, as a rule, only in children. The lymphadenoid formations of the pharynx, including all the tonsils of the pharynx, do not have afferent vessels.

Innervation of the pharynx. Maxillary nerve (second branch of the trigeminal nerve), glossopharyngeal nerve, accessory nerve, vagus nerve and the sympathetic trunk are involved in the formation pharyngeal nerve plexus (plexus pharyngeus), which is located on the back and side walls of the pharynx. This plexus provides motor and sensory innervation to the pharynx.

Motor innervation of the upper pharynx is provided mainly by glossopharyngeal nerve (n. glossopharyngeus), middle and lower sections - recurrent laryngeal nerve (n. laryngeus reccurens), branches of the vagus nerve.

Sensitive innervation of the upper pharynx is carried out by the second branch of the trigeminal nerve, the middle - by the branches of the glossopharyngeal nerve and the lower - internal branch superior laryngeal nerve from the vagus nerve system.

3.2. CLINICAL PHYSIOLOGY OF THE PHARYNX

The pharynx, being part of the alimentary and respiratory tract, is involved in the following vital important functions: act of eating(sucking and swallowing) respiratory, protective, resonator and speech.

Eating food in the first months of a child’s life is possible only through the motor act of sucking. At sucking the organs of the oral cavity create a negative pressure within 100 mm Hg, due to which the liquid is drawn into the oral cavity. At the moment of sucking, the soft palate is pulled down and moves closer to the root of the tongue, closing the oral cavity from behind, which allows breathing through the nose. After sucking the liquid into the oral cavity, sucking and breathing are interrupted and the act of swallowing occurs, then breathing resumes,

and the liquid is again sucked into the oral cavity. In adults, after chewing, a food bolus forms in the area of ​​the root of the tongue. The resulting pressure on the root of the tongue causes the act of swallowing - the pharyngeal constrictors contract in the form of peristalsis, the muscles of the soft palate and the palatine arches. Swallowing - a complex coordinated reflex act that ensures the movement of food from the oral cavity into the esophagus. The act of swallowing involves the muscles of the tongue, pharynx and larynx, the movement of which occurs in concert and in a certain sequence. In the act of swallowing, there are three phases, following one after another without interruption: oral- arbitrary, pharyngeal- involuntary (fast) and esophageal – involuntary (slow).

The first phase of the act of swallowing is voluntary - by lifting the tongue, the food bolus moves beyond the anterior arches - is under the control of the cerebral cortex and is carried out thanks to impulses coming from the cortex to the swallowing apparatus. The second phase - the movement of the food bolus down the pharynx to the entrance to the esophagus - is involuntary and is an unconditioned reflex that occurs when the receptors of the soft palate and pharynx are irritated. Damage to the reception mucosa of the upper pharynx can disrupt the act of swallowing, as it is interrupted reflex arc. This phenomenon can be observed with strong anesthesia of the pharyngeal mucosa. At the beginning of the second phase, the larynx rises, the epiglottis presses against the root of the tongue and falls, closing the entrance to the larynx; The arytenoid cartilages come closer together, as do the vestibular folds, narrowing the vestibular part of the larynx. As a result of contraction of the muscles of the palatine arches, the superior pharyngeal constrictor, the food bolus moves into the middle part of the pharynx. At the same moment, the soft palate rises and is pulled back, pressed against the back wall of the pharynx, thereby separating the nasopharynx from the oropharynx. In the middle part of the pharynx, the middle and lower constrictors cover the bolus of food and push it downwards. Elevation of the larynx, hyoid bone and pharynx facilitates the passage of the bolus. The third phase is involuntary, long-term - the approach of the food bolus to the entrance to the esophagus causes a reflex opening of the entrance to the esophagus and the active movement of the bolus along the esophagus due to the peristaltic contraction of its muscles. After the pharynx is freed from the food bolus, it is restored starting position. The duration of the act of swallowing is 6-8 s. The act of eating affects many

physiological functions in the body: breathing, blood circulation, gas exchange.

The mechanism for swallowing liquid is somewhat different. Due to the contraction of the muscles of the floor of the mouth, tongue and soft palate, such high pressure is created in the oral cavity that the liquid is injected into the relaxed upper esophagus and reaches the entrance to the stomach without the participation of pharyngeal constrictors and esophageal muscles. This process lasts 2-3 s.

On the anterior and posterior surfaces of the mucous membrane of the soft palate, the posterior wall of the pharynx, lingual surface The epiglottis contains scattered taste buds, thanks to which the pharynx performs a taste function. There are four types of taste sensations: 1) sweet, 2) sour, 3) salty and 4) bitter. Taste irritations are transmitted drum string (chorda tympani), glossopharyngeus (n. glossopharyngeus) And wandering (n. vagus) nerves. In children, the surface of distribution of taste sensations is more extensive than in adults.

Speech function pharynx consists of resonating sounds arising in the larynx. The formation of voice timbre occurs in the cavities of the larynx, pharynx, nose, paranasal sinuses and mouth. The larynx creates sound of a certain pitch and strength. The formation of vowels and consonants occurs mainly in the oral and to a lesser extent in the pharyngeal cavities. When pronouncing vowel sounds, the soft palate separates the nasopharynx from the oral cavity; consonant sounds are pronounced with the soft palate lowered.

Congenital defects of the hard palate, occurring in the nasal cavity and nasopharynx pathological processes(adenoids, polyps, neoplasms, swelling of the mucous membrane, paresis and paralysis of the soft palate, etc.) lead to pathological change voice timbre - nasality (rhinolalia) and distorted pronunciation of speech sounds. There are two types of nasality - open (rhinolalia aperta) And closed (rhinolalia clausa). With an open nasal tone, the nasopharynx and oropharynx are not completely separated, and a wide gap is formed between them, through which the main stream of air is directed into the nasal cavity. Open nasality is observed in congenital

cleft of the hard and soft palate, defects of the hard and soft palate, shortening of the soft palate, paresis and paralysis of the soft palate.

When the nasal resonator is turned off, a closed nasal sound develops. It is observed with adenoids, cicatricial fusion of the soft palate with the posterior wall of the pharynx, neoplasms, and choanal polyps.

In respiratory function all its departments are involved in the pharynx.

At calm breathing through the nose, the velum palatine hangs down freely, touching the root of the tongue, as a result of which the oral cavity is separated from the pharyngeal cavity. However, if the nasal passage is impaired, breathing occurs through the mouth, the velum of the palate rises, the tongue flattens and lowers, allowing an air stream to pass through.

Relaxation of the muscles of the pharynx, soft palate and tongue during sleep is the main reason snoring (ronchopathy), which is usually observed in individuals with a thickened soft palate and an elongated uvula, in the absence of a pharyngeal reflex and sharp decline muscle tone of the uvula and soft palate, as well as in people who drink alcohol and smoke a lot.

The occurrence of snoring is facilitated by impaired nasal breathing, for example due to the formation of nasal polyps, adenoids, deviated nasal septum, increased body weight in people with short and thick necks, etc.

Protective function The pharynx is expressed in the fact that when a foreign body or sharply irritating substances (chemical and thermal effects) enter it, a reflex contraction of the muscles of the pharynx occurs, its lumen narrows, which delays the deeper penetration of the irritating substance. At the same time, the muscles located above the foreign body relax, which helps push it out.

In the pharynx, the air continues after the nasal cavity to be warmed and cleared of dust, which adheres to the mucus covering the walls of the pharynx, and along with it is removed by expectoration or swallowed and neutralized in gastrointestinal tract. Mucus and saliva contain lysosomal and digestive enzymes, mediators, antibodies, trace elements, and vitamins. Leukocytes and lymphocytes also play a protective role, penetrating into the oral cavity and pharynx from blood vessels mucous membrane and lymphadenoid tissue.

3.3. PHYSIOLOGY OF LYMPHADENOID PHARYNGEAL RING

Lymphadenoid (lymphatic, lymphoid) tissue is represented by three structural types: (1) a mass of mature lymphocytes, among which relatively rarely there are (2) follicles, which are spherical (oval) in shape with clear boundaries of accumulation of lymphocytes of varying degrees of maturity and (3) reticular connective tissue tissue in the form of a cellular system of trabeculae that supports the mass of lymphocytes.

The lymphatic structures of the body are divided into three groups:

Lymphatic tissue of the spleen and bone marrow located in the path of the general blood flow; she is classified as lymph-blood barrier;

lymph nodes lying in the path of lymph flow; they are classified as lymphointerstitial barrier. The lymph nodes produce antibodies during infection;

Tonsils, along with lymphoid granules of the pharynx and larynx, Peyer's patches and solitary intestinal follicles, are classified as lymphoepithelial barrier, where lymphocytopoiesis and antibody formation occur, and where there is close contact between the internal and external environment body.

The lymphoid apparatus in the pharynx is located in a ring-like manner, which is why it was called the “lymphadenoid pharyngeal ring” by Waldeyer-Pirogov. It is formed by two palatine tonsils (I and II), one pharyngeal or nasopharyngeal (III), one lingual (IV) and two tubal (V-VI) (Fig. 3.9).

There are accumulations of lymphoid tissue on the posterior and lateral walls of the pharynx, in the pyriform sinuses and in the area of ​​the ventricles of the larynx.

There are a number of features that distinguish the palatine tonsils from other lymphoid formations of the pharynx, which allows the palatine tonsils to occupy a special place in the physiology and pathology of the lymphadenoid pharyngeal ring. These signs are as follows.

In the palatine tonsils there are lacunae that turn into crypts, which branch in a tree-like manner up to 4-5 orders and spread throughout the entire thickness of the tonsil, while in the lingual and pharyngeal tonsils there are not crypts, but grooves or clefts without branches.

Rice. 3.9. Scheme of the lymphadenoid pharyngeal ring: 1 – palatine tonsils; 2 – pharyngeal tonsil (adenoids); 3 – lingual tonsil; 4 – tubal tonsils

Lymphoepithelial symbiosis has its own characteristics: in all tonsils, except the palatine tonsils, it extends only to their surface. In the palatine tonsils, the lymphoid mass is in contact with the epithelium on a large surface of the crypt walls.

The epithelium here is easily permeable to lymphocytes and antigen in reverse side, which stimulates the production of antibodies.

The palatine tonsils are surrounded by a capsule - a dense connective tissue membrane covering the tonsil on the lateral side. The lower pole and pharyngeal surface of the tonsil are free from the capsule. The pharyngeal and lingual tonsils do not have a capsule.

In the paratonsillar tissue of the upper pole of the palatine tonsils there are sometimes located Weber's mucous glands, which do not communicate with crypts.

Lymphadenoid tissue undergoes reverse development over time. The pharyngeal tonsil undergoes involution starting at 14-15 years of age, the lingual tonsil reaches its maximum development by 20-30 years. Involution of the palatine tonsils also begins at 14-15 years of age and persists until old age.

The main function of the tonsils is like other lymphatic organs - lymph nodes, spleen, Peyer's patches of the intestine, etc. - is lymphocyte formation- lymphopoiesis. Lymphopoiesis occurs in the centers of the follicles (germinal centers), then, upon maturation, lymphocytes are pushed to the periphery

follicles, from here they enter the lymphatic pathways and the general lymph flow, as well as onto the surface of the tonsils. In addition to follicles, the formation of lymphocytes can also occur in the lymphoid tissue surrounding the follicles.

The study of the immunological role of the palatine tonsils has proven their participation in formation of immunity(antibody formation), especially at a young age. This is facilitated by the fact that the location of the palatine tonsils on the path of the main entrance gate for various infectious pathogens and toxic products ensures close contact of the mucous membrane of the tonsils with the bacterial agent, and this, in turn, underlies the formation of immunity. The very structure of the crypts - their narrowness and tortuosity, the large total surface of their walls - contributes to long-term contact of antigens and the lymphoreticular tissue of the tonsil.

It should be noted that, being an immune (antibody-forming) organ, the palatine tonsils physiological conditions do not lead to significant permanent immunization of the body. The palatine tonsils make up only a small part of the lymphoepithelial apparatus located in other organs. The ability of the palatine tonsils to form antibodies is most pronounced in the period before puberty. However, in adults, tonsil tissue can retain this function.

Palatine tonsils perform elimination function, participating in the removal of excess lymphocytes. The large area of ​​contact between lymphadenoid tissue and the epithelium in the crypts plays an important role in the migration of lymphocytes across the surface of the mucous membrane of the tonsils, maintaining a constant level of lymphocytes in the blood.

Many researchers admit enzymatic function tonsils of the pharyngeal ring, in particular the palatine tonsils. Biochemical analyzes made it possible to detect various enzymes in the tissue of the tonsils, as well as in migrating lymphocytes - amylase, lipase, phosphatase, etc., the content of which increases after eating. This fact confirms the participation of the palatine tonsils in oral digestion.

The lymphadenoid pharyngeal ring has a close connection with the endocrine glands - the thymus, thyroid gland, pancreas, adrenal cortex. Although the palatine tonsils do not have endocrine functions, there is a close relationship

communication in the pituitary gland - adrenal cortex - lymphatic tissue system, especially before puberty.

The pharynx is a hollow organ that is also part of the digestive and respiratory systems. It looks like a muscular tube that originates at the base of the skull and connects nasal cavity with the larynx and in its lower sections passes into the esophagus.

Structure of the pharynx

The pharynx begins at the base of the skull, connects the nasal cavity with the larynx, and passes into the esophagus.

Taking into account the anatomical and physiological characteristics, the pharynx is usually divided into 3 parts:

1. Nasal.
2. Oral.
3. Laryngeal.

The nasopharynx looks like a small cavity and occupies the uppermost parts of the organ. It connects the inner part of the nose through the choanae with the underlying respiratory tract, namely the larynx. This section of the pharynx is stationary and located at the level of the first two cervical vertebrae. There are openings on the lateral surfaces of the nasopharynx eustachian tubes, which provide connection between the pharynx and the tympanic cavity.

The oropharynx is a continuation of the nasal part of the organ. It has a direct connection with the oral cavity through the pharynx, which is an opening limited on the sides by the palatine arches, above by the soft palate, and below by the root of the tongue. The oral part of the pharynx serves as the crossroads of the digestive and respiratory tracts; it is directly involved in the passage of food and air.

At the level of the upper parts of the epiglottis, the next part of the pharynx begins - the laryngopharynx. It is located at the level of the 4th-5th cervical vertebrae, behind the larynx, so that the posterior wall of the latter becomes the anterior wall of the pharynx. In this case, in a state of rest, the walls of the organ are in contact with each other and diverge only during the act of swallowing. On the anterior surface of the pharynx there is an entrance to the larynx with pear-shaped pockets to the right and left of it. Inferiorly, the laryngopharynx narrows and passes into the esophagus.

Lympho-epithelial pharyngeal ring

Lymphoid formations of the pharynx are represented by tonsils and small follicles. The latter are located on the back surface of the pharynx (in the form of granules), behind the palatine arches (lateral ridges), in pear-shaped pockets at the entrance to the larynx.

The tonsils, located in the throat in the form of a ring, play a protective role, being part of the immune system. There are six of them in humans:

• two palatines,
• one pharyngeal,
• one lingual,
• two pipes.

The pharyngeal and tubal tonsils are located in the nasal part of the pharynx on the upper (in the zone of its transition to the posterior) and lateral walls.

The pharyngeal tonsil should be given special attention. Its second name is . In diseases of the upper respiratory tract, it becomes inflamed, increasing in size, and interferes with free nasal breathing. If such problems are often repeated, then the adenoid tissue grows so much that it leads to chronic disorder breathing through the nose. This can contribute to the development of deformation of the facial skeleton, hypoxia and frequent colds. This amygdala is most pronounced in childhood. With the onset of puberty, it begins to gradually decrease and undergoes reverse development.

The palatine tonsils are located in the oral part of the pharynx between the palatine arches. These tonsils have enough complex structure and are connected to the lateral surface of the pharynx using a fibrous capsule. They consist of connective tissue trabeculae, between which there are clusters of lymphocytes in the form of follicles.

On the free surface of the tonsils, facing the pharynx, there are more than 16 deep slits or lacunae with many branches. The surface of these cracks is covered with multilayer flat epithelium, which is constantly rejected, and the tonsils cleanse themselves. In addition to the epithelium, the lumen of the lacunae contains immune cells and microorganisms. However, deeply and tree-like branched lacunae are not always emptied in full. In combination with frequent upper respiratory tract infections, this contributes to the development.

The lingual tonsil is located at the root of the tongue and is often connected to the lower poles of the palatine tonsils.

Structure of the organ wall

The wall of the pharynx consists of 4 main layers:

• mucous,
• fibrous,
• muscular,
• adventitia.

The mucous membrane lines inner surface pharynx, it contains a large number of mucous glands and is covered with stratified epithelium, with the exception of the nasopharynx. In this area, the structure of the mucous membrane is somewhat different, since it is covered with columnar ciliated epithelium, which continues here from the nasal cavity.

The fibrous membrane is a thin connective tissue plate, fused with the mucous and muscular layers, which is attached to the bones of the base of the skull - from above, to the thyroid cartilage and hyoid bone - from below.

The muscular layer of the pharynx consists of striated muscle fibers, lifting and compressing the pharynx. On the outside, the muscles are covered with adventitia, which is loosely connected to the surrounding tissues.

Behind the pharynx and on the sides of it there are cellular spaces, the presence of which contributes to rapid spread inflammation on surrounding tissues and the development of complications.

Physiology of the pharynx

The pharynx is actively involved in the act of swallowing, facilitating the passage of a bolus of food from the oral cavity into the esophagus.

The pharynx is of great importance in the human body. Its main functions are:

1. Ensuring the flow of air into the lower parts of the respiratory tract and back.
2. Participation in the act of swallowing (due to peristaltic contraction of the muscles that compress the pharynx, palatine arches and soft palate) and passage of the food bolus from the oral cavity into the esophagus.
3. Creates an obstacle in the form of a reflex contraction of the muscles of the pharynx on the path of penetration of foreign bodies and irritants into the respiratory tract and digestive tube.
4. Serves as a sound resonator together with the inner part of the nose and paranasal sinuses (gives the voice an individual sound).
5. Protective function (in the pharynx, warming and purification of air coming from the nasal cavity or mouth continues; the presence of a lymphoepithelial pharyngeal ring and the bactericidal properties of mucus protect the body from the introduction of infectious agents).

Conclusion

The normal functioning of the pharynx is very important for the body. Any disruptions in the work of this body affect general condition. This may make breathing or swallowing difficult, which poses a threat to human health and life.

Educational video “Throat”:

The pharynx is part of the digestive canal and at the same time the respiratory tract, connecting the oral cavity and esophagus, as well as the nasal cavity and larynx. Since the paths of food and air intersect in the pharynx, it has devices that allow you to separate one from the other and, most importantly, prevent particles of food or water from entering respiratory tract.

Structure of the pharynx

In an adult, the pharynx is a funnel-shaped tube about 10-15 cm long, located behind the nasal and oral cavity and larynx. The upper wall of the pharynx is fused with the base of the skull; in this place on the skull there is a special protrusion - the pharyngeal tubercle. The cervical spine is located behind the pharynx, so the lower border of the pharynx is determined at the level between the VI and VII cervical vertebrae: here it narrows and passes into the esophagus. Adjacent to the lateral walls of the pharynx on each side large vessels(carotid arteries, internal jugular vein) and nerves (vagus nerve).

According to the organs located anterior to the pharynx, it is divided into 3 parts: upper - nasal, middle - oral - and lower - laryngeal.

Nasopharynx
The nasal part of the pharynx (nasopharynx) serves only to conduct air. From the nasal cavity, air enters this part of the pharynx through 2 large openings called choanae. Unlike other parts of the pharynx, the walls of its nasal part do not collapse, because they are firmly fused with the neighboring bones.

Oropharynx
The oral part of the pharynx (oropharynx) is at the level of the oral cavity. The function of the oral part of the pharynx is mixed, since both food and air pass through it. The transition point from the oral cavity to the pharynx is called the pharynx. From above, the pharynx is limited by a hanging fold (velum palatine), ending in the center with a small tongue. With each swallowing movement, as well as when pronouncing guttural consonants (g, k, x) and high notes, the velum palatine rises and separates the nasopharynx from the rest of the pharynx. When the mouth is closed, the tongue adheres tightly to the tongue and creates the necessary tightness in the oral cavity, preventing the lower jaw from sagging.

Laryngeal part of the pharynx
The laryngeal part of the pharynx is the lowest part of the pharynx, lying behind the larynx. On its front wall there is an entrance to the larynx, which is closed by the epiglottis, which moves like a “lifting door”. The wide upper part of the epiglottis descends with each swallowing movement and closes the entrance to the larynx, preventing food and water from entering the respiratory tract. Water and food move through laryngeal part pharynx into the esophagus.

Interaction of the pharynx with the tympanic cavity

On the side walls of the nasal part of the pharynx, on each side there is an opening of the auditory tube, which connects the pharynx with the tympanic cavity. The latter belongs to the organ of hearing and is involved in the conduction of sound. Thanks post tympanic cavity with the pharynx, the air pressure in the tympanic cavity is always equal to atmospheric pressure, which creates necessary conditions for transfer sound vibrations. Any person has probably encountered the effect of stuffy ears when taking off an airplane or going up in a high-speed elevator: the ambient air pressure changes quickly, but the pressure in the tympanic cavity does not have time to adjust. The ears become blocked, the perception of sounds is impaired. After some time, hearing is restored, which is facilitated by swallowing movements (yawning or sucking on a lollipop). With each swallow or yawn, the pharyngeal opening of the auditory tube opens and a portion of air enters the tympanic cavity.

The structure and significance of the tonsils

In the nasal part of the pharynx there are such important formations as the tonsils, which belong to the lymphoid (immune) system. They are located on the path of possible introduction of foreign substances or microbes into the body and create a kind of “security posts” on the border of the internal and external environment for the body.

The unpaired pharyngeal tonsil is located in the area of ​​the fornix and posterior wall of the pharynx, and the paired tubal tonsils are located near the pharyngeal openings of the auditory tube, i.e., in the place where microbes, along with the inhaled air, can enter the respiratory tract and tympanic cavity. Enlargement of the pharyngeal tonsil (adenoid) and its chronic inflammation can lead to difficulty in normal breathing in children, so it is removed.

In the area of ​​the pharynx, at the border of the oral cavity and pharynx, there are also paired palatine tonsils - on the side walls of the pharynx (sometimes in everyday life they are called tonsils) - and the lingual tonsil - at the root of the tongue. These tonsils play a significant role in protecting the body from pathogens that enter through the mouth. With inflammation of the palatine tonsils - acute or chronic tonsillitis (from the Latin tonsilla - tonsil) - there may be a narrowing of the passage to the pharynx and difficulty swallowing and speaking.

Thus, in the pharynx area, a kind of ring of tonsils is formed, which participate in the body’s defense reactions. The tonsils are significantly developed in childhood and adolescence, when the body grows and matures.

Structure of the pharyngeal wall

The basis of the pharyngeal wall is formed by a dense fibrous membrane, which is covered on the inside by the mucous membrane and on the outside by the muscles of the pharynx. The mucous membrane in the nasal part of the pharynx is lined with ciliated epithelium - the same as in the nasal cavity. IN lower parts The mucous membrane of the pharynx acquires a smooth surface and contains numerous mucous glands that produce a viscous secretion, which helps the bolus of food slide when swallowing.

Among the muscles of the pharynx, longitudinal and circular are distinguished. The circular layer is much more pronounced and consists of 3 constrictor muscles (constrictors) of the pharynx. They are located in 3 floors, and their sequential contraction from top to bottom leads to the pushing of the food bolus into the esophagus. When swallowing, two longitudinal muscles expand the pharynx and lift it towards the bolus of food. The muscles of the pharynx work in concert with every swallowing movement.

How does swallowing occur?

Swallowing is a reflex act, as a result of which a bolus of food is pushed from the oral cavity into the pharynx and then moves into the esophagus. Swallowing begins with food irritating the receptors in the oral cavity and the back wall of the pharynx. The signal from the receptors enters the swallowing center located in the medulla oblongata (brain section). Commands from the center are sent through the corresponding nerves to the muscles involved in swallowing. The bolus of food, formed by the movements of the cheeks and tongue, is pressed against the palate and pushed towards the pharynx. This part of the act of swallowing is voluntary, that is, it can be suspended at the request of the swallower. When a bolus of food reaches the level of the pharynx (at the root of the tongue), swallowing movements become involuntary.

Swallowing involves the muscles of the tongue, soft palate and pharynx. The tongue moves the food bolus, while the velum palatine rises and approaches the back wall of the pharynx. As a result, the nasal part of the pharynx (respiratory) is completely separated from the rest of the pharynx by means of the velum palatine. At the same time, the neck muscles lift the larynx (this is noticeable by the movements of the protrusion of the larynx - the so-called Adam's apple), and the root of the tongue presses on the epiglottis, which descends and closes the entrance to the larynx. Thus, when swallowing, the airways are closed. Next, the muscles of the pharynx itself contract, causing the bolus of food to move into the esophagus.

The role of the pharynx in the breathing process

When breathing, the root of the tongue is pressed against the palate, closing the exit from the oral cavity, and the epiglottis rises, opening the entrance to the larynx, where a stream of air rushes. From the larynx, air passes through the trachea to the lungs.

Cough as a protective reaction of the body

If the swallowing process is disrupted by talking, laughing while eating, water or food can enter the respiratory tract - into the nasopharynx, causing extreme discomfort, and into the larynx, leading to attacks of painful convulsive cough. Cough is defensive reaction, caused by irritation of the mucous membrane of the larynx with food particles and helping to remove these particles from the respiratory tract.

Instead of a conclusion

The pharynx has undergone a long evolution. Its prototype is branchial apparatus fish, which was reorganized when animals came to land due to air respiration.

Among the functions of the pharynx is a resonator. The uniqueness of voice timbre is largely due to the individual characteristics of the structure of the pharynx. In the human embryo, the formation of several endocrine glands - the thyroid, parathyroid and thymus - is associated with the development of the pharynx.

Thus, despite its small size, the pharynx has a complex structure and plays an important role in the human body.

Pharynx, pharynx, - an unpaired organ located in the head and neck area, is part of the digestive and respiratory systems. The pharynx is a funnel-shaped tube flattened in the anteroposterior direction, suspended from the base of the skull. At the top it is attached to the base of the skull, at the back - to the pharyngeal tubercle of the basilar part of the occipital bone, on the sides - to the pyramids of the temporal bones (anterior to the external opening of the carotid canal), then to the medial plate of the pterygoid process. At the level of the VI-VII cervical vertebrae, the pharynx passes into the esophagus. The openings of the nasal cavity (choanae) and oral cavity (pharynx) open into the pharynx. The food mass from the oral cavity through the pharynx during the act of swallowing enters the pharynx, and then into the esophagus. Air from the nasal cavity through the choanae or from the oral cavity through the pharynx also enters the pharynx and then into the larynx. Thus, the pharynx is the crossroads of the digestive and respiratory tracts.

The posterior surface of the pharynx is adjacent to the anterior surface of the body of the cervical vertebrae, separated from the latter by the prevertebral muscles and the prevertebral plate of the cervical fascia. 1.between the posterior surface of the pharynx and the plate of the cervical fascia there is a so-called retropharyngeal space,spdtium re tropharyngeum, filled with loose connective tissue in which the retropharyngeal lymph nodes are located. Lateral from the pharynx are the neurovascular bundles of the neck, the internal jugular vein, and the vagus nerve; in front of the pharynx are the nasal cavity (above), the oral cavity and larynx (below).

The pharynx has its greatest transverse dimension at the level of the nasal cavity and oral cavity. The length of the pharynx is on average 12-14 cm. In addition to the anterior, posterior and lateral walls, the pharynx has an upper wall, which is formed by a part of the base of the skull covered with mucous membrane, located anterior to the foramen magnum.

The top wall is vault of the pharynx,fornix pharyngis. The posterior wall of the pharynx has no openings, and the anterior one is almost absent, since the openings are located here: choanae, pharynx and entrance to the larynx

The pharynx has three parts, corresponding to the organs located in front of it: nasal, oral and laryngeal. Nasal part of the pharynx,pars nasalis pharyngis, located at the level of the choanae and makes up the upper part of the pharynx, oropharynx,pars oralis pharyngis, extends from the velum to the entrance to the larynx and is located at the level of the pharynx (level of the III cervical vertebra). Laryngeal part of the pharynx,pars laryngea pharyngis, is the lower part of the pharynx and is located from the level of the entrance to the larynx to the transition of the pharynx to the esophagus. .The nasal part of the pharynx (nasopharynx) refers only to the respiratory tract, the oral part - to the digestive and respiratory tract, the laryngeal part - only to the digestive tract. The upper (nasal) part of the pharynx constantly gapes, since its walls do not collapse. During the act of swallowing, the nasal part of the pharynx (nasopharynx) is separated from the rest of the pharynx by the velum palatine, and the epiglottis closes the entrance to the larynx, so the food mass is sent only to the esophagus and does not enter either the nasal cavity or the laryngeal cavity.

On the inner surface of the pharynx, at the junction of its upper wall with the posterior one, and in the area of ​​the fornix, there is a small elevation formed by the accumulation of lymphoid tissue in the mucous membrane - pharyngeal (adenoid) tonsil,ton- silla pharyngealis (adenoidea). The pharyngeal tonsil is well developed in children, and in adults it is weakly visible on the inner surface of the posterior wall of the pharynx. On the lateral walls of the pharynx, behind the choanae, at the level of the posterior end of the inferior nasal concha, a funnel-shaped pharyngeal opening of the auditory tube,ostiutn pharyngeum tubae auditivae. The auditory tube connects the middle ear cavity with the pharynx cavity and helps equalize the atmospheric pressure inside the tympanic cavity. The pharyngeal opening of the auditory tube is limited posteriorly and superiorly by the tubal ridge, torus tubarius.

In the mucous membrane around the pharyngeal opening of the auditory tube and in the thickness of the anterior surface of the tubal ridge there is an accumulation of lymphoid tissue - tubal tonsil,tonsilla tubdria. Thus, the entrance to the pharyngeal cavity from the nasal and oral cavities, as well as the initial part of the auditory tube, is surrounded by accumulations of lymphoid tissue. So, behind the choana there are the pharyngeal and tubal tonsils, at the opening of the pharynx - the palatine and lingual tonsils. In general, this complex of six tonsils is called the lymphoid ring (Pirogov-Waldeyer ring).

On the front wall of the lower (larynx) part of the pharynx there is an opening leading to the larynx. It is bounded above by the epiglottis, on the sides by the aryepiglottic folds, and below by the arytenoid cartilages of the larynx. Below this opening there is a protrusion of the larynx - the result of protrusion of the larynx into the pharyngeal cavity. Lateral and slightly above this protrusion in the wall of the pharynx is located pear-shaped pocket,gesho-ssus piriformis.

The wall of the pharynx is formed mucous membrane,tunica mu- cosa, which lies on a dense connective tissue plate that replaces the submucosa. In the lower part of the pharynx, this plate has a loose structure submucosa,tela submucosa, and in the upper sections there is a fibrous structure and is called pharyngobasilar"fascia, fascia pha- r yngobasildris. Located outside the submucosa muscle membrane,tunica musculdris, And connective tissue on I'm a shell- adventitia, adventitia.

The mucous membrane lining the inside of the pharyngeal wall

does not form folds in the upper sections, as it adheres

mediocre to dense and strong pharyngeal-basilar

fascia. At the level of the nasopharynx, the mucous membrane is covered with ciliated (ciliated) epithelium, and below it is covered with stratified squamous epithelium in accordance with the function of these parts of the pharynx. In the mucous membrane of the pharynx there are mucous glands, the secretion of which, released into the pharynx, moisturizes its walls and facilitates the sliding of the bolus of food when swallowing.

On the outside, the submucosa and above the pharyngobasilar fascia are covered with pharyngeal muscles formed by striated muscle tissue.

Muscles of the pharynx form pharyngeal constrictors - constrictors (upper, middle and lower) and longitudinal muscles - pharyngeal levators (stylopharyngeal and tubopharyngeal muscles) (Fig. 198; see Table XV of the Appendix).

Superior pharyngeal constrictorT.constrictor pharyngis su­ period, starts from the medial plate of the pterygoid process of the sphenoid bone, from pterygomandibular suture,raphe pterygomandibulare, - fibrous strip stretched between the pterygoid hook and the lower jaw, from the lower jaw (linea rnylohyoidea) and the root of the tongue in the form of a continuation of the transverse muscle of the tongue. The fibers of the superior pharyngeal constrictor run posteriorly and downward, fusing along the midline on the posterior surface of the pharynx with the same bundles on the opposite side. Since the superior bundles of this constrictor do not cover the wall of the pharynx in the uppermost section, the pharynx is formed by the pharyngobasilar fascia and mucous membrane, covered externally by adventitia.

Middle pharyngeal constrictorm. constrictor pharyngis medius, starts from the greater and lesser horns of the hyoid bone. Next, the bundles of this muscle fan out upward and downward, heading to the posterior surface of the pharynx, where they “fuse with the muscle bundles of the opposite side. The upper edge of the middle constrictor overlaps the lower part of the muscle bundles of the superior pharyngeal constrictor.

Inferior pharyngeal constrictorm. constrictor pharyngis info­ rior, begins on the lateral surface of the thyroid and cricoid cartilages. Its muscle bundles fan out backwards, downwards, horizontally and upwards, cover the lower half of the middle constrictor and grow together with the bundles of the same muscle on the opposite side on the posterior surface of the pharynx.

The lower muscle bundles of the lower pharyngeal constrictor extend onto the posterior surface of the beginning of the esophagus.

Due to the fusion of the muscle bundles of the constrictors of the right and left sides, a pharyngeal suture is formed on the posterior surface of the pharynx along the midline, raphe pharyngis.

I stylopharyngeal muscle,T.stylopharyngeus, begins on the styloid process of the temporal bone and goes down and anteriorly, penetrates between the upper and middle constrictors and ends in the wall of the pharynx. Some of the bundles of this muscle reach the upper edge of the thyroid cartilage.

Tubalopharyngeal muscle,T.salpingopharyngeus, steam room, originates on the lower surface of the cartilage of the auditory tube, near the pharyngeal opening. The muscle bundles descend down, connect to the velopharyngeal muscle and are woven into the lateral wall of the pharynx.

The muscles of the pharynx take part in the act of swallowing. When a food bolus enters the pharyngeal cavity, the longitudinal muscles lift the pharynx upward, as if pulling it over the food bolus, and the pharyngeal constrictors contract sequentially from top to bottom, as a result of which the food bolus is pushed towards the esophagus. The outside of the pharynx is covered with a thin connective tissue layer (adventitia), through which it contacts nearby organs.

Vessels and nerves of the pharynx. In the wall of the pharynx, the ascending pharyngeal artery (from the external carotid artery), pharyngeal branches (from the thyrocervical trunk - branches of the subclavian artery), pharyngeal branches (from the ascending palatine artery - branches of the facial artery) branch. Venous blood flows through the pharyngeal plexus, then the pharyngeal veins into the internal jugular vein. The lymphatic vessels of the pharynx drain into the retropharyngeal and deep lateral (internal jugular) lymph nodes. Innervation of the pharynx is carried out by the branches of the glossopharyngeal (IX pair) and vagus (X pair) nerves, as well as through the laryngopharyngeal branches (from sympathetic trunk), which form a nerve plexus in the wall of the pharynx.