Pharynx(pharyx) is the initial part of the digestive tract and respiratory tract. It is a hollow muscular organ located behind the nasal cavity, mouth and larynx at the level of 1-6 cervical vertebrae. The lower part of the pharynx passes into the esophagus. The walls of the pharynx consist of 4 membranes: mucous, fibrous, muscular and adventitia.
Mucous membrane contains many mucous glands and in the submucosal layer a large amount of lymphoid tissue in the form of separate nodules and large clusters that form the tonsils. The histological structure of the lymphadenoid tissue of the pharynx is of the same type - between the connective tissue fibers there is a mass of lymphocytes with their globular clusters, which are called follicles.
Fibrous membrane is a plate of dense connective tissue closely associated with the mucous and muscle layer.
Muscular membrane consists of circular and longitudinal muscles that compress the pharynx and lift it.
Adventitia - dense connective membrane - covers the muscular layer of the pharynx from the outside.
The posterior wall of the pharynx is located in front of the cervical vertebrae. In this area, between the pharyngeal fascia and the fascia of the spine, there is a retropharyngeal space filled with loose tissue and lymphoid tissue, which is especially pronounced in children. The communication of this space with the mediastinum is of great clinical importance in the development of a retropharyngeal abscess.
The lateral walls of the pharynx border on the neurovascular bundle of the neck.
Anatomically, the pharynx is divided into 3 sections: the nasopharynx, the oropharynx, and the hypopharynx.
Nasopharynx- the upper part of the pharynx, the front border of which are the choanas and the edge of the opener. Behind the nasopharynx there are 1 and 2 cervical vertebrae. The lower border of the nasopharynx is a mental continuation of the plane of the hard palate posteriorly. The mucous membrane of this part of the pharynx, like the mucous membrane of the nasal cavity, is covered with stratified squamous ciliated epithelium and contains a large number of mucous glands.
On the lateral walls of the nasopharynx are the mouths of the auditory tubes, around them there is an accumulation of lymphoid tissue - paired tubal tonsils. In the fornix of the nasopharynx is the third unpaired pharyngeal tonsil - adenoids, consisting of 5-9 cushion-like accumulations of lymphoid tissue up to 25 mm long.
Oropharynx- the middle part of the pharynx, located at the level of 3-4 cervical vertebrae, is limited only by the posterior and lateral walls. In this part of the pharynx, the intersection of the respiratory and digestive tracts occurs.
In front of the oropharynx, it communicates with the oral cavity through an opening called the pharynx. The borders of the pharynx are from above the soft palate, uvula, on the sides - the anterior and posterior arches, between which the paired palatine tonsils are located. The lower border of the oropharynx is the root of the tongue.
The structure of the tonsils is of great clinical importance. The outer or fibrous surface of the tonsil is associated with the underlying tissue and is covered with a layer of connective tissue called the tonsil capsule. Fibrous cords depart from it, forming fine-fibrous plexuses, in which spherical accumulations of lymphocytes - follicles - are located. Lymphocytes of these follicles are formed during embryonic development and play an important role in the formation of local and general immunity.
On the free surface of the tonsils there are cracks, or lacunas, which go deep into the tissue and branch out there. The number of lacunae ranges from 8 to 30. The mucous membrane of the palatine tonsils has areas through which lymphocytes emerge to the surface of the lacunae. Food debris, desquamated epithelium, microbes and lymphocytes falling into the lacunae form plugs that contribute to the development of the inflammatory process in the amygdala. During the act of swallowing, the amygdala self-cleansing, but, due to individual anatomical characteristics, it may be impaired.
On the posterior wall of the pharynx there are small accumulations of lymphadenoid tissue, called granules or follicles, and significant accumulations on the lateral walls of the pharynx - lateral ridges.
The lower part of the pharynx - laryngopharynx- located at the level of 5-6 cervical vertebrae. It tapers in the form of a cone and is located in front of the entrance to the larynx. Between the protruding cartilages of the larynx and the lateral walls of the pharynx there are depressions - pear-shaped sinuses, which pass into the initial part of the esophagus. An unpaired lingual tonsil is located on the front wall in the region of the tongue root.
All of these tonsils and accumulations of lymphadenoid tissue on the posterior wall of the pharynx form the Valdeer-Pirogov pharyngeal ring, which performs a protective function.
Pharynx- a muscular organ located in the neck and is an integral part of the respiratory and digestive systems.
The structure of the pharynx
Located behind the nasal and oral cavities and in front of the occipital bone, the pharynx has the shape of a funnel-shaped tube about 10-15 cm long. 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. Behind the pharynx is the cervical spine, so the lower border of the pharynx is determined at the level between the VI and VII cervical vertebrae: here, narrowing, it passes into the esophagus. Large vessels (carotid artery, internal jugular vein) and nerves (vagus nerve) adjoin the lateral walls of the pharynx on each side.
Three sections of the pharynx
- upper (nasopharynx)
- middle (oropharynx)
- lower (laryngeal)
Nasopharynx is intended only for conducting air, which from the nasal cavity enters here through 2 large choanas. Unlike other parts of the pharynx, the walls of its nasal part do not collapse, since they are firmly adhered to the adjacent bones.
On the side walls of the nasopharynx (on each side) there are openings of the auditory tube connecting the pharynx with the tympanic cavity of the organ of hearing. Due to this communication, the air pressure in the tympanic cavity is always equal to atmospheric, which creates the necessary conditions for the transmission of sound vibrations.
During takeoff, the atmospheric pressure changes so rapidly that the pressure in the tympanic cavity does not have time to correct itself. As a result, the ears become blocked and the perception of sounds is impaired. If you yawn, suck on a lollipop or swallow, your hearing is restored very quickly.
The nasopharynx is the location of the tonsils, the most important formations related to the immune system. The unpaired pharyngeal tonsil is located in the region of the fornix and the posterior wall of the pharynx, and the paired tonsils are located near the pharyngeal openings of the auditory tube. Being located on the path of the possible introduction of foreign substances or microbes into the body, they create a kind of protective barrier.
The enlargement of the pharyngeal tonsil (adenoids) and its chronic inflammation can make it difficult for children to breathe and is therefore removed.
The oropharynx, located at the level of the oral cavity, has a mixed function, since both food and air pass through it. The place of transition from the oral cavity to the pharynx - the pharynx - at the top is limited by a hanging fold (palatine curtain), ending in the center with a small tongue. With each swallowing movement, as well as with the pronunciation of laryngeal consonants ("g", "k", "x") and high notes, the palatine curtain rises and separates the nasopharynx from the rest of the pharynx. When the mouth is closed, the tongue fits snugly against the tongue and creates the necessary tightness in the oral cavity to prevent the lower jaw from sagging.
On the lateral walls of the pharynx there are paired palatine tonsils, the so-called tonsils, and at the root of the tongue - the lingual tonsil. These tonsils also play a significant role in protecting the body from harmful bacteria that enter the mouth. With inflammation of the tonsils, a narrowing of the passage into the pharynx and difficulty in swallowing and speaking are possible.
Thus, in the area of the pharynx, a kind of ring of tonsils is formed, which are involved in the protective reactions of the body. The tonsils are highly developed in childhood and adolescence, when the body grows and matures.
The organ of taste. It is our tongue, covered with more than five thousand taste buds of various shapes.
Types of taste buds of the tongue
- mushroom papillae (mainly occupy the front two thirds of the tongue)
- grooved (located at the root of the tongue, they are relatively large and easy to see)
- leafy (tightly spaced folds on the side of the tongue)
Each of the papillae contains taste buds, which are also found in the epiglottis, the back of the pharynx, and the soft palate.
The kidneys have their own specific set of taste buds that are receptive to different taste sensations. So, on the tip of the tongue there are more receptors for sweetness, the edges of the tongue feel sour and salty better, and its base is bitter. Taste zones can overlap one another, for example, in the zone where the sweet taste occurs, there can be receptors for bitter taste.
There are approximately 10,000 taste buds in the human mouth.
At the apex of the taste bud is a taste hole (pore) that opens on the surface of the mucous membrane of the tongue. Substances dissolved in saliva penetrate through the pore into the fluid-filled space above the taste bud, where they come into contact with the cilia - the outer parts of the taste buds. Excitation in the receptor occurs as a result of the interaction of a substance with a nerve cell and is transmitted through sensory nerves to the center of taste (gustatory zone) located in the temporal lobe of the cerebral cortex, where four different sensations arise: salty, bitter, sour and sweet. The taste of food is a combination of these sensations in different proportions, to which the sensation of the smell of food is also added.
The laryngeal region of the pharynx lies behind the larynx. On its front wall is the 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 the laryngeal pharynx into the esophagus.
The wall of the pharynx. Its basis is formed by a dense fibrous membrane, covered from the inside by a mucous membrane, and from 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 the lower parts of the pharynx, the mucous membrane, becoming smooth, contains numerous mucous glands that produce a viscous secret that facilitates the sliding of the food lump when swallowing.
The role of the pharynx in breathing
Having passed through the nasal cavity, the air is warmed, moistened, cleansed and enters first into the nasopharynx, then into the mouth of the pharynx and, finally, into its laryngeal part. 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 the air stream rushes.
Among the functions of the pharynx there is also a resonator one. The originality of the timbre of the voice is largely due to the individual characteristics of the structure of the pharynx.
When talking or laughing while eating, food can enter the nasopharynx, causing extremely unpleasant sensations, and into the larynx, leading to bouts of excruciating convulsive cough - a protective reaction caused by irritation of the laryngeal mucosa with food particles and helps to remove these particles from the respiratory tract
28. Pharynx: topography, departments, messages, wall structure, blood supply and innervation. Lymphoepithelial ring.
Pharynx (pharynx)- a muscular organ with a fibrous base, connecting the oral cavity with the esophagus and the nasal cavity with the larynx. In the pharynx, the digestive tract is crossed by the respiratory tract (see Atl.). The length of the pharynx of an adult is 12-15 cm. The pharynx is attached by the expanded part (vault) to the base of the skull, and the lower narrowed part at the level of the VI cervical vertebra passes into the esophagus. Between the vertebral bodies and the posterior pharyngeal wall there is a pharyngeal space filled with loose connective tissue. This allows significant movement of the pharynx when swallowing. The pharynx is divided into three sections - the nasopharynx, the oropharynx, and the larynx.
Nasopharynx - the uppermost, complex part of the pharynx. Through choanas it communicates with the nasal cavity. The nasopharynx is separated from the oral cavity by a soft palate, which is tightly attached to the root of the tongue during breathing, and, on the contrary, when swallowed, separating it from the rest of the pharynx. On the lateral walls of the nasopharynx, at the level of the choanas, there are openings of the auditory (Eustachian) tubes. By connecting the nasopharynx to the middle ear cavity, these tubes ensure that the air pressure in the middle ear is equalized with external pressure. Between the opening of the auditory tube and the soft palate lies the tubal tonsil, and on the vault of the nasopharynx - the pharyngeal.
Oropharynx through the pharynx communicates with the oral cavity (see Atl.). Tapering downwards, it goes into laryngeal part of the pharynx, the front wall of which is adjacent to the back of the larynx.
Outside, the pharynx is covered adventitious shell, passing from below to the esophagus.
Muscular wall The pharynx is built of striated muscles, which consists of three pairs of flat annular muscles-compressors and two pairs of weak muscles with a longitudinal direction of fibers that raise the pharynx (see Atl.). The sequential contraction of the constrictor muscles (as well as the muscles of the soft palate and tongue) during the passage of the food bolus causes the act of swallowing. The muscles of the pharynx are innervated by the vagus and lingopharyngeal nerves.
Mucous membrane the nasopharynx, as well as the nasal cavity, is lined with multi-row ciliated epithelium. The rest of the pharynx is lined with stratified squamous non-keratinizing epithelium. The mucous membrane contains small mucous glands scattered in all its parts.
In the wall of the pharynx, under the epithelium, there are accumulations of lymphoid tissue - tonsils: unpaired pharyngeal and lingual and paired tubal and palatine (clearly visible through an open mouth). They surround the entrance to the nasopharynx and oropharynx and form the lymphoepithelial ring (see Atl.). Lymphocytes multiplying in the tonsils and numerous plasma cells perform a protective function, preventing the penetration of infection. The tonsils are especially developed in children. The defeat of the tonsils occurs in children more often than in adults. A sharp increase in them often serves as the first sign of angina, scarlet fever, diphtheria and other diseases. The pharyngeal tonsil in adults is little visible or disappears altogether. But in children, it can be significant. With pathological growth (adenoids), it makes it difficult to breathe through the nose.
Motor function of the initial section of the digestive tract. The motor activity of the oral cavity and pharynx is associated with the processes accompanying the absorption of food - chewing and swallowing, as well as (in children of the first year of life) sucking. All these movements are reflex and become possible due to the rhythmic activity of neurons in the corresponding parts of the central nervous system and primarily in the medulla oblongata.
During chewing food is rubbed in the mouth. Chewing involves the upper and lower jaws, teeth, tongue, cheeks, and chewing muscles. At the same time, food is chopped, which greatly facilitates its subsequent digestion and absorption. Although chewing is a voluntary action, it is mainly carried out as an involuntary reflex act: when food pieces come into contact with the palate and teeth, reflex chewing movements occur. At the same time, food moves with the help of coordinated movements of the tongue and cheeks along the oral cavity. A complete set of teeth is required to maximize food chopping. In the process of chewing, salivation is reflexively triggered. Food moistened with saliva is easily swallowed.
Swallowing also constitutes a complex coordinated voluntary act. The food lump along the middle of the tongue is directed to the back of the mouth. The tip of the tongue presses it against the hard palate, while the sequential contraction of the muscles of the tongue and mouth sends a lump of food down the throat. When the food bolus reaches the pharynx, the soft palate blocks the entrance to the nasopharynx. At the same time, due to the contraction of the pharyngeal muscles, the larynx rises, the entrance to it is closed by the epiglottis, breathing is reflexively interrupted for a short moment. Food passes into the esophagus. The striated muscles of the oral cavity and pharynx are controlled by impulses from the central nervous system. Thus, swallowing is an unconditioned reflex that occurs in response to stimulation of the receptors in the back of the oral cavity and pharynx. Swallowing movements are performed not only when food is consumed, but also in its absence, as well as during sleep.
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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 flow freely into the esophagus, and then into the stomach. In addition, due to the anatomical and physiological features, air from the nose into the lungs and in the opposite direction penetrates through the pharynx. 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, the occipital bone, and the temporal pyramidal bones. At the level of the 6-7th 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 and 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.
Nasal part
Pars nasalis functionally represents the respiratory part of the human pharynx. The walls of this section are motionless and therefore do not fall down (the main difference from other sections of the organ).
Choanae are located in the anterior wall of the pharynx, and the pharyngeal funnel-shaped openings of the auditory tube, which is a component of the middle ear, are located on the lateral surfaces. Behind and at the top, this hole is limited by a tubular ridge, which is formed by the protrusion of the cartilage of the auditory tube.
The border between the posterior and upper pharyngeal wall is occupied by an accumulation of lymphoid tissue (in the midline) called adenoids, which are not very pronounced in an adult.
Another accumulation of lymphatic tissue is located between the soft palate and the opening (pharyngeal) of the tube. That is, at the entrance to the pharynx there is an almost dense ring of lymphatic tissue: the lingual tonsil, palatine tonsils (two), pharyngeal and tubal (two) tonsils.
Mouth part
Pars oralis is the middle section in the pharynx, communicating in front of the pharynx with the oral cavity, and its posterior part is located at the level of the third cervical vertebra. The functions of the oral part are mixed, due to the fact that the digestive and respiratory systems intersect here.
Such a cross is a feature of the human respiratory system and was formed during periods from the primary intestine (its walls). Oral and nasal cavities were formed from the nasal primary bay, the latter being located above and slightly dorsally relative to the oral cavity. The trachea, larynx, and lungs have evolved from the (ventral) wall of the anterior intestine. That is why the head section of the gastrointestinal tract is located between the nasal cavity (above and dorsally) and the respiratory tract (ventrally), which explains the intersection of the respiratory and digestive systems in the pharyngeal region.
Laryngeal part
Pars laryngea is the lower part of the 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 front wall.
The structure and function of the pharynx
The basis of the pharyngeal wall is that it is attached to the bony base of the skull from above, lined with mucous inside, and outside with a muscular membrane. The latter is covered with a thin fibrous tissue, which unites the pharyngeal wall with adjacent 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 lower parts - with a flat multilayer epithelium, due to which the surface becomes smooth and the food lump 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 compressors: the upper constrictor, the middle constrictor and the lower pharyngeal constrictor. Starting at different levels: from the bones of the base of the skull, the lower jaw, the root of the tongue, the cartilage of the larynx and the hyoid bone, the muscle fibers are sent back and, when combined, form a seam of the pharynx along the midline.
The fibers (lower) of the lower constrictor are associated with the muscle fibers of the esophagus.
Muscle fibers longitudinal make up the following muscles: stylopharyngeal (M. stylopharyngeus) originates from the styloid process (part of the temporal bone), goes down and, dividing into two bundles, enters the pharyngeal wall, and is also attached to (its upper edge); palatopharyngeal muscle (M. palatopharyngeus).
The act of swallowing
Due to the presence in the pharynx of the intersection of the digestive and respiratory tract, 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 with the back of the tongue is pressed against the palate (hard) and then pushed into the pharynx. At this time, the soft palate is pulled up (due to muscle contractions tensor veli paratini and levator veli palatini). So the nasal (respiratory) section of the pharynx is completely separated from the oral section.
At the same time, the muscles that are located above the hyoid bone pull the larynx upward. At the same time, the root of the tongue goes down and presses on the epiglottis, due to which the latter descends, closing the passage to the larynx. After that, successive contractions of constrictors occur, due to which the lump 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 lump.
Blood supply and innervation of the pharynx
The pharynx is supplied mainly from the pharyngeal ascending artery (1), the upper thyroid (3) and 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 membrane, and then along the pharyngeal veins (4) into the internal jugular vein (5).
Lymph flows into the cervical lymph nodes (deep and retropharyngeal).
The pharyngeal innervation is carried out by the pharyngeal plexus (plexus pharyngeus), which is formed by the branches of the vagus nerve (6), sympathetic syvol (7) and glossopharyngeal nerve. In this case, the sensitive innervation passes along the glossopharyngeal and vagus nerves, the only exception is the stylopharyngeal muscle, the innervation of which is carried out only by the glossopharyngeal nerve.
Dimensions (edit)
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) averages 12-14 cm. The transverse size of the organ is 4.5 cm, that is, more anteroposterior size.
Diseases
All diseases of the pharynx can be divided into several groups:
- Inflammatory acute pathologies.
- Injuries and foreign bodies.
- Chronic processes.
- Lesions of the tonsils.
- Sore throats.
Inflammatory acute processes
Among acute inflammatory diseases, the following can be distinguished:
- Pharyngitis is acute - damage to the lymphoid tissue of the pharynx due to the multiplication of viruses, fungi or bacteria in it.
- Pharyngeal candidiasis - 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 of an infectious nature. Angina can be: catarrhal, lacunar, follicular, ulcerative film.
- Abscess in the area of the root of the tongue - purulent tissue damage in the area of the hyoid muscle. The reason for this pathology is infection of wounds or as a complication of inflammation of the lingual tonsil.
Injury to the pharynx
The most common injuries are:
1. Various burns caused by electrical, radiation, thermal or chemical effects. Thermal burns develop due to the ingress of too hot food, and chemical burns - when exposed to chemical agents (more often acids or alkalis). There are several degrees of tissue damage during burns:
- The first degree is characterized by erythema.
- The second stage is the formation of bubbles.
- The third degree is necrotic tissue changes.
2. Foreign bodies in the pharynx. These can be bones, pins, food particles, and so on. The clinic of such injuries depends on the depth of penetration, localization, and the size of the foreign body. Stitching pains are more common, followed by pain when swallowing, coughing, or a feeling of suffocation.
Chronic processes
Among chronic lesions of the pharynx, it is 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 immunodeficiencies.
- Chronic tonsillitis is an autoimmune pathology of the 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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The human body is unique, each organ has its own function, the failure of one of them leads to disruption of the functions of most, and in some cases of all anatomical structures. The work of organs can be compared with the mechanism of a clock, one tiny detail has broken down and the clock stops running, therefore the human body is arranged according to the same principle. One of the organs responsible for two vital processes in the body at once is the pharynx. Its main functions are respiratory and digestive functions.
The structure of the pharynx
The pharynx has a simple structure, it is a funnel-shaped tube that originates from the cervical vertebra and descends down to the esophagus to 5-7 vertebra. The size of the pharynx varies from 12 to 16 centimeters. The organ consists of muscles, mucous membrane and lymphoid tissue. The cylindrical tube is separated from the vertebra by soft tissues, which allows the organ to be mobile. The main features of the structure of the pharynx are that until the swallowing function is activated, the airways are open, and at the time of swallowing food, the larynx blocks breathing so that food is directed into the esophagus, and not the lungs.
In addition, the pharynx has a lot of lymphoid tissue, which allowed it to form tonsils in the mouth. The tonsils serve as the so-called guardians at the entrance to the pharynx; they have immune cells that block the entry of microbes into the larynx and down the respiratory tract.
In its structure, the pharynx has three sections:
the nasopharynx is the section that is connected between the nose, mouth and larynx; the oropharynx is an extension of the nasopharynx. This section is separated from the oral cavity by the soft palate, palatine arches and the back of the tongue; the laryngopharynx, this section originates approximately in the region of the 4th vertebra (age features can be noted). The larynx is located in this section, it consists almost entirely of muscles and is a conductor of food to the esophagus.
The structure of the organ implies age-related changes. So, in infants, the length of the pharynx is about three centimeters, in the first two years of life, the size doubles, and in an adult this parameter is 12-16 centimeters. Also, the lower edge of the organ, due to the increase in size, is shifted downward. In a newborn, the end of the pharynx is located in the region of the 3-4 cervical vertebra, and by adolescence, the lower edge is located at the level of the 6-7 vertebra. Age-related changes also occur in the pharyngeal opening of the auditory tube. In childhood, it has the shape of a slit, and during the period of growing up it acquires an oval shape. Because of this age-related feature, children are more susceptible to stenosis and the development of asphyxia, since the lumen of the larynx is very narrow, any inflammatory process in the organ leads to swelling and blocking of the lumen, which is accompanied by impaired respiratory function.
The tonsils also tolerate age-related changes, their peak growth occurs at the age of two years. In the period of 12-14 years, a reverse development occurs, that is, the lymphoid tissue decreases slightly in size. After this period, age-related changes in the amygdala practically do not have any more.
So, it was said about the respiratory and digestive functions, but in addition to these two important processes, there is more. The speech function, the ability to pronounce sounds in a person appears thanks to the vocal cords located in the middle part of the larynx, and the soft palate also participates in this process. Due to the muscle layer and mobility, the anatomical structure allows you to correctly distribute the air flow, while creating the timbre of the voice. If the soft palate has any anatomical changes in its structure, this leads to a violation of the vocal function.
And the pharynx has one more function - a protective one. The process is made possible by lymphoid tissue, which contains immune agents and a specific mucosal coating on the back wall. This wall is covered with mucus with the smallest villi, which in turn also trap dust and bacteria that enter so that they do not spread to the larynx and further. That is why quite often inflammatory processes occur precisely in the throat, the infection lingers here, without dropping lower, and causes symptoms of a cold.
Diseases of the pharynx and larynx
There are a number of pathological processes that can cause disturbances in the work of the larynx and pharynx. The main diseases of this organ include:
inflammatory processes. These are pharyngitis, laryngitis, ARVI, influenza, whooping cough, etc. As a result of infection in the form of a virus or bacteria, a disease develops, depending on which department and which harmful microbe the lesion occurs, this or that diagnosis is made. So, for example, with laryngitis, the larynx is affected, and pharyngitis affects the oropharynx; adenoids are a developmental anomaly caused by frequent colds. Adenoids are formed more often in children under the age of ten. They are a proliferation of lymphoid tissue in the area of the pharyngeal tonsil. If adenoids have arisen, they must be removed, as they negatively affect a number of organs and functions. The child develops an incorrect pronunciation of sounds, this condition is often called "gundositis". Also, complications can affect the thyroid gland and heart; congenital malformation. This process can imply many developmental disorders, as a rule, all of them are detected even in the perinatal period or in children of the first year of life. For such anomalies, surgical intervention is always used, and it should be performed as early as possible; candidiasis, characterized by a lesion of the pharynx with a fungus, Candida group. Popularly called thrush, it manifests itself in the form of a white curd bloom, occurs mainly in infants, since their protective functions are still poorly developed. Pathology is treated with antifungal drugs; trauma and foreign bodies entering the larynx or pharynx. This problem occurs most often when food or other objects get stuck in the larynx, which leads to respiratory failure and requires urgent help, since a person can simply suffocate; an abscess is a purulent inflammatory process characterized by the appearance of a purulent sac in the pharyngeal region. It is treated with an antibacterial drug, with large sizes, requires surgical intervention, but the operation consists in hiding the bag so that its contents come out, and then drug therapy.
The pharynx is an important organ in the human body that undergoes age-related changes throughout life and performs its unique and vital functions, such as respiratory, swallowing, speech and protective. The organ is susceptible to various diseases that negatively affect its functions, therefore, it requires attention from medical personnel and appropriate treatment. For any changes in the normal functioning of the larynx or pharynx, you should consult a doctor, and not self-medicate, otherwise even a minor illness can cause serious complications.
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The pharynx is a cylindrical, slightly sagittally compressed funnel-shaped muscle tube 12 to 14 cm long, located in front of the cervical vertebrae. The vault of the pharynx (upper wall) connects to the base of the skull, the posterior part is attached to the occipital bone, the lateral parts to the temporal bones, and the lower part passes into the esophagus at the level of the sixth vertebra of the neck.
The pharynx is the intersection of the respiratory and digestive tracts. The food mass from the oral cavity during the swallowing process 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.
The structure of the pharynx
In the anatomical structure of the pharynx, there are three main parts - the nasopharynx (upper part), oropharynx (middle part) and hypopharynx (lower part). The oropharynx and nasopharynx are connected to the oral cavity, and the hypopharynx is connected to the larynx. The pharynx is connected to the oral cavity through the pharynx, and it communicates with the nasal cavity through the choanae.
The oropharynx is an extension of the nasopharynx. The soft palate, palatine arch, and dorsum of the tongue separate the oropharynx from the oral cavity. The soft palate descends directly into the pharyngeal cavity. During swallowing and pronouncing sounds, the palate rises upward, thereby ensuring articulate speech and preventing food from entering the nasopharynx.
The laryngopharynx begins in the region of the fourth to fifth vertebra and, smoothly descending downward, passes into the esophagus. The anterior surface of the laryngopharynx is represented by the area where the lingual tonsil is located. Once in the oral cavity, the food is crushed, then the food lump enters the esophagus through the laryngopharynx.
On the lateral walls of the pharynx there are funnel-shaped openings of the auditory (Eustachian) tubes. This structure of the pharynx helps to balance the atmospheric pressure in the tympanic cavity of the ear. In the area of these holes, the tubal tonsils are located in the form of paired accumulations of lymphoid tissue. Similar accumulations are found in other parts of the pharynx. Lingual, pharyngeal (adenoid), two tubal, two palatine tonsils form a lymphoid ring (Pirogov-Valdeyer ring). The lymphoid ring prevents foreign substances or microbes from entering the human body.
The pharyngeal wall consists of the muscular layer, the adventitia and the mucous membrane. The muscular layer of the pharynx is represented by a group of muscles: the stylopharyngeal muscle lifting the larynx and pharynx and arbitrary paired striated muscles - the upper, middle and lower pharyngeal compressors, narrowing its lumen. When swallowing, by the efforts of the longitudinal muscles, the pharynx rises, and the striated muscles, contracting sequentially, push the food lump.
The submucosa with fibrous tissue is located between the mucous membrane and the muscular membrane.
The mucous membrane in different locations is different in its structure. In the laryngopharynx and oropharynx, the mucosa is covered with stratified squamous epithelium, and in the nasopharynx - ciliated epithelium.
Functions of the pharynx
The pharynx takes part in several vital functions of the body at once: food intake, breathing, voice formation, defense mechanisms.
All parts of the pharynx are involved in the respiratory function, since air passes through it, entering the human body from the nasal cavity.
The voice-forming function of the pharynx consists in the formation and reproduction of sounds generated in the larynx. This function depends on the functional and anatomical state of the neuromuscular apparatus of the pharynx. During the pronunciation of sounds, the soft palate and tongue, changing their position, close or open the nasopharynx, providing the formation of the timbre and pitch of the voice.
Pathological changes in the voice can occur due to impaired nasal breathing, congenital defects of the hard palate, paresis or paralysis of the soft palate. Violation of nasal breathing most often occurs due to an increase in the nasopharyngeal tonsil as a result of the pathological proliferation of its lymphoid tissue. Overgrowth of the adenoids leads to an increase in pressure inside the ear, while the sensitivity of the eardrum is significantly reduced. The circulation of mucus and air in the nasal cavity is inhibited, which contributes to the multiplication of pathogens.
The alimentary function of the pharynx consists in the formation of acts of sucking and swallowing. The protective function is performed by the lymphoid ring of the pharynx, which, together with the spleen, thymus and lymph nodes, forms a single immune system of the body. In addition, many cilia are located on the surface of the pharyngeal mucosa. When the mucous membrane is irritated, the pharyngeal musculature contracts, its lumen narrows, mucus is secreted and a pharyngeal gag reflex appears. With a cough, all harmful substances adhering to the cilia are excreted.
ANATOMICAL FEATURES
The anatomy of the human pharynx is designed in a special way in order to perform the functions of respiration and digestion. It is in this section that these paths intersect, but its device allows food to penetrate only into the esophagus, and air into the respiratory system.
The structure of the nasopharynx is designed in such a way that during the swallowing movements, the airways are open, but at the moment a lump of food moves along the esophagus, they are blocked by the muscles of the larynx. These mechanisms prevent food from entering the airway.
The pharynx is considered as an entrance gate for a variety of microorganisms, including pathogenic ones. Due to the fact that its inner surface contains an accumulation of lymphoid tissue, which is a constituent part of the immune system, it captures and neutralizes the pathogenic microflora.
Location of the pharynx in relation to other organs:
in front - connection with the larynx and transition into 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 - goes into the esophagus. STRUCTURE OF THE HUMAN'S PHOTO
When considering the anatomical features of the pharynx, there are 3 main divisions.
Main departments:
Nasopharynx, or nasal upper section. It is located above the palate at the same level as the first and second vertebrae of the neck, its communication with the nasal cavity occurs through the choanae. With the help of the holes of the Eustachian tube, located at the level of the lower nasal passage in the pharynx, there is a relationship with the inner tympanic cavity of the ear. This anatomical feature allows equalizing the pressure in both cavities and ventilating the latter. For this reason, nasal breathing is important not only for the respiratory system, but also for the auditory function. Between the soft palate and the exit of the Eustachian passage, 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-Valdeyer ring. Overgrowth, or hypertrophy of the pharyngeal tonsil, can cause choanal or auditory tube orifices to block, causing symptoms of breathing difficulties and dysfunction of the Eustachian canal in children under 14 years of age. In older age, the pharyngeal tonsil atrophies, and this problem can no longer arise. The border between the upper and middle section is conditional, the separation occurs when a line is drawn backward relative to the hard palate. The oropharynx is the oral, or middle part. Includes the area from the palate to the larynx. The connection to the oral cavity occurs through the pharynx. From above, the pharynx is blocked by the palate and uvula, from below it is limited by the root of the tongue. On both sides of the pharynx are the palatine arches. The oropharynx is formed by the posterior and two lateral walls. It is here that 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 isolation of the nasopharynx occurs when performing the listed actions. The pharyngeal wall can be seen with the mouth wide open. The laryngopharynx is the laryngeal, or lower part. A narrow passage located behind the larynx. The front, two side and back walls are distinguished here. While at rest, the front and back walls are closed together. 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 vertebra of the neck, narrows and continues with the esophagus. On average, the length of the organ is about 12-14 cm, its inner space is formed by the pharyngeal cavity. The middle and upper parts are united with the oral cavity, and the lower ones are connected with the larynx.
The organ wall consists of muscles, connective tissue and mucous membranes. The latter is represented by a multinucleated ciliary 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 tightly grows together with the muscle layer. Between the muscle layer and the mucous membranes, there is a submucous layer, represented by fibrous tissue. Connective tissue inclusions can be found in the buccal muscle and in the esophagus tissue.
Muscles of the pharynx:
styopharyngeal - controlled by consciousness, raises the larynx and pharynx; compressors (upper, middle, lower) - narrow the lumen of the pharynx.
The alternating work of these muscle groups helps the passage of food down towards the esophagus.
SWALLOWING PROCESS
The special structure and functions of the pharynx allow it to perform swallowing movements. The swallowing process occurs reflexively by tension and relaxation of different muscle groups.
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 tongue root. At the root of the tongue is a group of sensitive receptors, the irritation of which provokes muscle contraction, thereby raising the palate. At the same moment, the communication of the pharynx with the nasal cavity is blocked and food does not penetrate into the airways. The lump of food is pushed out with the tongue into the throat. Here, the muscles displace the hyoid bone, which causes the larynx to lift, and the epiglottis closes the airway. In the pharynx, with the help of alternating contractions of different muscle groups, a gradual passage of food towards the esophagus is ensured. SIP FUNCTIONS
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 unconditioned reflex act. Breathing is provided by all parts of the organ, since through them air flows from the nasal and oral cavity into the lower respiratory tract. This process is made possible by the connection of the pharynx with the larynx, choans and pharynx. Voice formation consists in the creation and reproduction of sounds, the formation of which is provided inside the larynx by the vocal cords. When pronouncing sounds, the tongue and the soft palate close and open the entrance to the nasopharynx, which ensures the timbre and pitch of the 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, protects 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, with irritation of the ciliated epithelium on the mucous surface, muscle contraction occurs, the lumen of the pharynx narrows, mucus is secreted and a cough begins, which acts as a protective reaction of the body.
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