How to restore the swallowing reflex. Dysphagia When swallowing, the soft palate closes the entrance to the

Chewing- a physiological act, which consists in grinding food substances with the help of teeth and the formation of a food lump. Chewing ensures the quality of mechanical processing of food and determines the time of its stay in the oral cavity, has a reflex stimulating effect on the secretory and motor activity of the stomach and intestines. Chewing involves the upper and lower jaws, chewing and mimic muscles of the face, tongue, soft palate. Mechanical processing of food between the upper and lower rows of teeth is carried out due to the movement of the lower jaw relative to the upper. An adult in a row on the right and left has teeth of different functional purposes - 2 incisors and one canine (biting off food), 2 small and 3 large molars that crush and grind food - a total of 32 teeth. The chewing process has 4 phases- the introduction of food into the mouth, indicative, basic and the formation of food coca.

chewing is regulated reflexively. Excitation from receptors of the oral mucosa (mechano-, chemo- and thermoreceptors) is transmitted through afferent fibers of the II, III branches of the trigeminal, glossopharyngeal, superior laryngeal nerve and tympanic string in chewing center which is located in the medulla oblongata. Excitation from the center to the chewing muscles is transmitted through the efferent fibers of the trigeminal, facial and hypoglossal nerves. Excitation from the sensory nuclei of the brainstem along the afferent pathway through the specific nuclei of the thalamus switches to the cortical section of the gustatory sensory system, where the analysis and synthesis of information from the receptors of the oral mucosa is carried out.

At the level of the cerebral cortex, sensory impulses are switched to efferent neurons, which send regulatory influences along descending pathways to the chewing center of the medulla oblongata.

swallowing- a reflex act by which food is transferred from the RP to the stomach. The act of swallowing consists of 3 phases:

oral (arbitrary);

pharyngeal (involuntary, fast);

esophageal (involuntary, slow).

IN 1st phase the tongue pushes the food bolus down the throat.

In 2nd phase stimulation of pharyngeal entry receptors triggers a complex coordinated act, including:

raising the soft palate with blocking the entrance to the nasopharynx;

contraction of the muscles of the pharynx with pushing the food bolus into the esophagus;

opening of the upper esophageal sphincter.

IN esophageal phase stimulation of the esophagus triggers a peristaltic wave generated by both somatic nerves and intramural neurons. When the food bolus reaches the distal end of the esophagus, the lower esophageal sphincter opens briefly

Swallowing regulation mechanism:

The food lump irritates the receptors of the tongue, pharynx. In these receptors, APs are generated, which are sent in the form of nerve impulses along the afferent nerves (n. trigeminus, n. glossopharyngeus and superior laryngeal nerve) to the swallowing center, which is located in the medulla oblongata, just above the center of respiration. The swallowing center is excited and sends nerves along the efferent nerves (n. trigeminus, n. glossopharyngeus, n. hypoglossus, n. vagus) to the muscles, which promotes the food bolus in the oral cavity and pharynx.

The function of the swallowing center is closely related to the function of the SCC and the respiratory center. The act of swallowing is performed arbitrarily until the food bolus falls behind the palatine arches. Then the process of swallowing becomes involuntary. The possibility of voluntary swallowing indicates participation in the mechanism of swallowing of the CGM.

Solid food passes through the esophagus in 8-10 seconds, liquid - in 1-2 seconds. The food bolus moves along the esophagus with the help of peristaltic contractions of the muscles of the walls. The walls of the upper third of the esophagus contain striated muscles, the lower 2/3 - smooth muscles. The esophagus is innervated by parasympathetic and sympathetic nerves. Parasympathetic nerves (n. vagus) stimulate the motor function of the muscles of the esophagus, sympathetic nerves - weaken. From the esophagus, the food bolus enters the stomach, where it undergoes further mechanical and chemical processing.

69. Digestion in the stomach. Composition and properties of gastric juice. Regulation of gastric secretion. Phases of the separation of gastric juice. Features of gastric secretion during the digestion of proteins, fats, carbohydrates.

In the stomach, food mixed with saliva and mucus is retained from 3 to 10 hours for its mechanical and chemical processing. The stomach performs the following functions:

depositing food;

secretion of gastric juice;

mixing food with digestive juices;

its evacuation - movement in portions to the KDP;

absorption into the blood of a small amount of substances received with food;

excretion (excretion) together with gastric juice into the stomach cavity of metabolites (urea, uric acid, creatine, creatinine), substances that enter the body from outside (heavy metal salts, iodine, pharmacological preparations);

the formation of active substances (incretion) involved in the regulation of the activity of the gastric and other digestive glands (gastrin, histamine, somatostatin, motilin, etc.);

bactericidal and bacteriostatic action of gastric juice);

removal of poor-quality food, preventing it from entering the intestines.

Gastric juice is secreted by glands, which consist of main (glandulocytes, secrete enzymes), parietal (perital, secrete HCl) and accessory (mucocytes, secrete mucus) cells. In the fundus and body of the stomach, the glands consist of the main, parietal, and accessory cells. The pyloric glands are composed of principal and accessory cells and do not contain parietal cells. The juice of the pyloric region is rich in enzymes and mucoid substances and has an alkaline reaction. The juice of the fundus of the stomach is acidic.

The amount and composition of gastric juice:

During the day, a person secretes from 1 to 2 liters of gastric juice. The amount and composition of it depends on the nature of the food, its reactionary properties. The gastric juice of humans and dogs is a colorless transparent liquid with an acidic reaction (pH = 0.8 - 5.5). The acidic reaction is provided by HCl. Gastric juice contains 99.4% water and 0.6% solids. The dry residue contains organic (products of hydrolysis of proteins, fats, lactic acid, urea, uric acid, etc.) and inorganic (salts of Na, K, Mg, Ca, rhodanide compounds) substances. Gastric juice contains enzymes:

proteolytic (break down proteins) - pepsin and gastrixin;

Pepsin is released in an inactive form (pepsinogen) and activated by HCl. Pepsin hydrolyzes proteins to polypeptides, peptones, albumose and partially to amino acids. Pepsin is active only in an acidic environment. The maximum activity is manifested at pH = 1.5 - 3, then its activity weakens and gastrixin acts (pH = 3 - 5.5). There are no enzymes that break down carbohydrates (starch) in the stomach. Digestion of carbohydrates in the stomach amylase saliva until the chyme is completely oxidized. In an acidic environment, amylase is not active.

MeaningHCl:

converts pepsinogen into pepsin, creates an optimal environment for the action of pepsin;

softens proteins, promotes their swelling and thereby makes them more accessible for the action of enzymes;

promotes curdling of milk;

under its influence, a number of enzymes are formed in the duodenum and small intestine: secretin, pancreozymin, cholecystokinin;

stimulates the motor function of the gastrointestinal tract;

has bactericidal and bacteriostatic action.

The value of mucus (mucoid) in the stomach:

protects the gastric mucosa from the damaging effects of mechanical and chemical food irritants;

adsorbs enzymes, therefore contains them in large quantities and thereby enhances the enzymatic effect on food;

adsorbs vitamins A, B, C, protects them from destruction by gastric juice;

contains substances that stimulate the activity of the gastric glands;

contains the Castle factor, which promotes the absorption of vitamin B12.

On an empty stomach in a person, gastric juice is not secreted or is secreted in a small amount. On an empty stomach, mucus predominates, which has an alkaline reaction. The secretion of gastric juice occurs during preparation for a meal (fire juice according to Pavlov) and while food is in the stomach. At the same time, they distinguish:

latent period is the time from the start of food entry into the stomach to the start of secretion. The latent period depends on the excitability of the gastric glands, on the properties of food, on the activity of the nerve center that regulates gastric secretion.

juicing period- continues as long as food is in the stomach.

Aftereffect period.

Regulation of gastric secretion (RGS):

Currently distinguished:

complex-reflex phase of RHD;

humoral phase of RHD, which is divided into gastric and intestinal.

Complex reflex phase includes unconditioned reflex and conditioned reflex mechanisms of RHD. The complex reflex phase was carefully studied by Pavlov in experiments with imaginary feeding (showing food - a conditioned reflex mechanism). Parasympathetic and sympathetic nerves are of great importance in RHD. Pavlov's experiments with transection of nerves showed that the parasympathetic nerves increase secretion, while the sympathetic ones weaken it. The same patterns are observed in humans. The medulla oblongata regulates secretion and ensures digestion in the stomach. The hypothalamus makes an assessment of food and its need for the body. KGM provides the formation of eating behavior.

Phase of gastric secretion stimulate:

food that enters the stomach. It irritates the receptors in the gastric mucosa, they generate action potentials, which in the form of nerve impulses along the afferent nerves enter the digestive center in the medulla oblongata. It is excited and sends nerve impulses along the efferent nerves (n. vagus) and enhances secretion.

gastrin produced by the gastric mucosa stimulates the release of HCl.

histamine produced by the gastric mucosa.

products of protein hydrolysis (amino acids, peptides).

bombesin - stimulates the production of gastrin by G-cells.

Phase of gastric secretion slow down:

secretin - produced by the mucous membrane of the small intestine;

cholecystokinin-pancreozymin;

intestinal enzymes (GIP - gastric intestinal peptide and VIP-harmone, somatostatin, enterogastron, serotonin);

Chyme, coming from the stomach to the duodenum, inhibits the release of HCl in the stomach.

phase of intestinal secretion stimulate:

acidic chyme entering the intestine from the stomach irritates mechanoreceptors and chemoreceptors, they generate AP, which in the form of NI through afferent nerves enter the center of digestion in the medulla oblongata. It is excited and sends nerve impulses along the efferent nerves (n. vagus) to the glands of the stomach, stimulating their function.

enterogastrin - secreted by the intestinal mucosa, enters the bloodstream and acts on the glands of the stomach.

protein hydrolysis products. In the intestines, they are absorbed into the blood and with it they enter the glands of the stomach, stimulating their function.

phase of intestinal secretion slow down:

products of hydrolysis of fats and starch. In the intestines, they are absorbed into the blood and with it they enter the glands of the stomach, inhibiting their function.

secretin.

cholecystokinin-pancreozymin.

enterogastron.

Gastric secretion during the digestion of various nutrients.

Adaptation of the secretory apparatus of the stomach to the nature of food is due to its quality, quantity, and diet. A classic example of adaptive reactions of the gastric glands is studied by I.P. Pavlovian reaction of the digestive glands in response to a meal containing mainly carbohydrates (bread), proteins (meat), fats (milk).

The most effective stimulant of secretion is protein food. Proteins and products of their digestion have a pronounced sap action. After eating meat, a rather vigorous secretion of gastric juice develops with a maximum at the 2nd hour. It lasts about 7 hours. A prolonged meat diet leads to an increase in gastric secretion to all food irritants, an increase in acidity and the digestive power of gastric juice. This suggests that under the influence of strong causative agents of secretion, a steady restructuring occurs in the activity of the gastric glands and the mechanisms of their regulation.

carbohydrate food(bread) - a weaker causative agent of secretion of gastric juice. Bread is poor in chemical stimulants of secretion, therefore, after taking it, a secretory response develops with a maximum at the 1st hour (reflex separation of juice), and then sharply decreases and remains at a low level for a long time (due to weak mobilization of humoral mechanisms of excitation of glandulocytes). With long-term nutrition of a person with carbohydrates, the acidity and digestive power of the juice decrease, which is a consequence of the adaptation of the stomach glands to food containing a small amount, the products of incomplete hydrolysis of which stimulate the production of hydrochloric acid and pepsinogen.

Fats milk cause gastric secretion in 2 stages: inhibitory and excitatory. This explains the fact that after the intake of fatty foods, the maximum secretion of juice is observed only by the end of the 3rd hour. The first portions of milk that got from the stomach to the duodenum have an inhibitory effect on the secretion of gastric juice. As a result of long-term nutrition with fatty foods, there is an increase in gastric secretion to all food irritants due to the second half of the secretory period. The digestive power of juice when using fats in food is lower compared to the juice released for meat, but higher than when eating carbohydrate foods.

The amount of nutrient juice, its acidity and proteolytic activity also depend on the amount and consistency of the food taken. As the volume of food increases, the secretion of gastric juice increases.

One of the severe manifestations of acute cerebrovascular accident is swallowing disorders with impaired food intake from the oral cavity to the esophagus (oropharyngeal, oropharyngeal, "high" dysphagia), which are traditionally considered within the bulbar or pseudobulbar syndromes.

Strokes as the cause of swallowing disorders account for 25% of all neurological diseases, primarily cerebral infarctions (80%). At the same time, dysphagia in the acute period of stroke is noted in 64-94% of cases, most often in the first 3-10 days; in the recovery period - in 23-50% of patients, and about 11% of patients at the rehabilitation stage still need tube feeding. Mortality among stroke patients with dysphagia is 27-37%.

The danger of swallowing disorders lies in the high risk of developing respiratory complications, aspiration pneumonia, tissue dehydration and activation of catabolic processes due to malnutrition.

Overall, lower respiratory tract infections develop in 12-30% of stroke patients. In patients with swallowing disorders, aspiration pneumonia develops in 30-48% of cases. One of the main ways for microorganisms to enter the respiratory system is the aspiration of the contents of the oral cavity and nasopharynx, which is observed in 40-50% of patients with strokes and increases the risk of developing pneumonia by 5-7 times.

The presence of dysphagia in patients with stroke and developed pneumonia increases mortality by 2.5-3 times. X-ray examination reveals manifestations of dysphagia in patients with strokes in 80% of cases and signs of food aspiration - in 45-56%.

Identification of fluoroscopic signs of a decrease or absence of the pharyngeal reflex increases the risk of developing infectious diseases of the respiratory system (IDDS) by 12 times, and the risk of developing persistent dysphagia is closely associated with the detection of fluoroscopic manifestations of ingestion of the contents of the oral cavity on the eve of the larynx or delayed evacuation of the contents of the oral cavity, as well as with presence of any clinical signs of swallowing disorders.

The combination of such clinical outcomes as persistent dysphagia, the development of IDDS, or fluoroscopic signs of aspiration is more often detected in patients with oral contents entering the larynx, with its delayed evacuation, in patients older than 70 years, and in male patients.

Along with aspiration, the risk of developing pneumonia is increased by depression of consciousness and being on artificial lung ventilation (ALV), nutrition through a nasogastric tube, old age, multiple localization of stroke foci, myocardial infarction, arterial hypertension, atrial fibrillation, previous diseases of the pulmonary system, diabetes mellitus, gastroprotection pump inhibitors.

Management of patients with pneumonia in an intensive care unit for stroke patients reduces 30-day mortality by 1.5 times.

Factors that increase the risk of developing pneumonia in patients with stroke:

• Aspiration.
• Oppression of consciousness.
• Finding on IVL.
• Feeding through a nasogastric tube.
• Elderly age.
• Multiple localization of stroke foci.
• Myocardial infarction.
• Arterial hypertension.
• Atrial fibrillation.
• Previous diseases of the pulmonary system.
• Diabetes.
• Taking proton pump inhibitors.

At the same time, the development of early (up to 72 hours) pneumonia is determined by the presence of previous strokes, the severity of the patient's condition, the localization of lesions in the brain stem or cerebellum, and late (after 72 hours) - by the presence of cardiodilation, previous pathology of the lungs and coma.

All patients with stroke, regardless of the severity of the lesion, should undergo standardized screening for dysphagia, which statistically significantly reduces the risk of developing nosocomial pneumonia and requires standard protocols for screening for dysphagia in institutions.

The pathogenesis of swallowing disorders is associated with the development of bulbar syndrome in 13.5% of cases, pseudobulbar syndrome in 31.2% and food bolus formation disorder syndrome in 55.3%. Signs of several syndromes can be combined in the same patient.

In hemispheric strokes, more severe dysphagia and more frequent respiratory complications are observed with bilateral localization of lesions (in 55.5 and 66.6% of patients, respectively), less often with the right hemisphere (37.5 and 25%) and left hemisphere (23 and 15, 3%) localization of foci.

Bilateral damage to the cortical-nuclear pathways is the cause of the development of pseudobulbar syndrome, the right-sided localization of the process with the involvement of cortical and subcortical structures causes a disorder of the gnostic component of the swallowing function, and the left-sided localization causes the development of buccal-lingual, oral apraxia, which also causes swallowing disorders. Damage to the cerebellum can also cause the development of dysphagia due to discoordination of the muscles of the tongue and pharynx.

At the same time, the right hemispheric localization of the stroke focus is combined with a predominant violation of the initiation of the act of swallowing, disorders of the pharyngeal phase of the swallowing process, a high risk of aspiration, and a slow recovery of the swallowing function (more than 2–3 weeks) against the background of minor disturbances in the oral transit of the food bolus.

Left-hemispheric strokes are accompanied by violations of the oral phase of the act of swallowing with poor processing of the food bolus, impaired food transit in the oral cavity, a disorder in the control of salivation and a feeling of difficulty in moving the muscles of the lips and tongue with a faster recovery, most often within 1-3 weeks.

In strokes with bilateral damage to the hemispheres, there is a violation of both the oral and pharyngeal phases of swallowing with a predominance of oral dysfunction and a longer recovery.

In stem strokes, there is an isolated or combined violation of the oral and pharyngeal phases of swallowing with a significant increase in the risk of aspiration and respiratory complications and slow recovery.

With hemispheric (supratentorial) localization of ischemic foci, the most associated with the development of dysphagia were the affected areas located in the internal capsule, primary somatosensory, motor and additional motor cortex, orbital-frontal cortex, subcortical nuclei - putamen, caudate nucleus and other basal ganglia, in contrast to from foci located in the insula and in the temporo-parietal cortex.

At the same time, after correcting the data taking into account the severity of stroke according to the NIHSS scale and the volume of the lesion, the statistical significance of this relationship remained only for foci with damage to the internal capsule.

The presence of dysphagia in patients with stroke increases the costs of treatment and rehabilitation of surviving patients by more than 6 times, taking into account the duration of impaired function recovery: videofluoroscopy 6 months after stroke reveals subclinical signs of swallowing disorders in more than 50% of surviving patients.

Anatomy and physiology of the act of swallowing

Afferent structures that provide the act of swallowing are receptors located on the mucous membrane of the tongue, palate, pharynx, centripetal fibers and sensory nuclei of V, IX and X pairs of cranial nerves, and efferent - motor nuclei of V, VII, IX, X and XII pairs of cranial nerves and their centrifugal fibers to the striated muscles of the tongue, cheeks, soft palate, pharynx and upper third (cervical part) of the esophagus.

The central link is the stem centers of swallowing regulation, which are the nuclei of the reticular formation of the brain stem and are located in the dorsolateral sections of the medulla oblongata on both sides below the nuclei of the solitary tract, the cortical centers of swallowing located in the posterior sections of the frontal lobes, the cortical centers of these sensory and motor analyzers in pre- and postcentral gyrus, centers of praxis and gnosis in the parietal lobes (precuneus), mechanisms of memory and volitional initiation (islet, cingulate gyrus, prefrontal cortex), as well as the connections of all these formations with each other.

Physiologically, the act of swallowing is a reflex and consists of 3 phases (damage to the nervous system causes a violation of the first two phases):

• oral (oral) - arbitrary,
• (oro) pharyngeal (pharyngeal, oropharyngeal) - fast, short involuntary;
• esophageal (esophageal) - slow, prolonged involuntary.

The stem centers of swallowing regulation are connected with the respiratory and vasomotor centers of the reticular formation, which ensures breath holding and an increase in cardiac activity during swallowing. Cortical centers of swallowing implement voluntary regulation of the act of swallowing.

Clinical manifestations of swallowing disorders

The clinical picture of dysphagia syndrome is caused by central or peripheral paresis of the muscles of the tongue, soft palate and constrictor muscles of the pharynx and is manifested by the following symptoms:

• difficulty in chewing, deposition of food behind the tertiary cheek;
• loss of food from the mouth while eating;
• drooling or inability to swallow saliva;
• swallowing disorders;
• regurgitation;
• choking when swallowing saliva, liquid or liquid food;
• coughing or coughing before, during, or after swallowing;
• change in voice quality during or after swallowing;
• difficulty breathing, shortness of breath after swallowing.

The holistic clinical picture of swallowing disorders is determined by the topic of the pathological process and may be different depending on the hemispheric or stem localization of the lesion, and may also be accompanied by other concomitant symptoms "next door".

With repeated (including lacunar and "silent") cortical and subcortical (hemispheric) strokes (in case of bilateral lesions of the corticobulbar tract) - clinic pseudobulbar syndrome:

• violation of the function of chewing and sagging of the lower jaw (central paresis of the masticatory muscles);
• dysfunction of swallowing in the oral phase (violation of the formation of the food bolus and its promotion to the root of the tongue) due to impaired movements of the tongue or cheek (central paresis of the muscles of the tongue or cheek);

accompanying symptoms:

• aphasia (with cortical strokes in the dominant hemisphere);
• dysarthria (with subcortical strokes or cortical strokes in the non-dominant hemisphere), caused by central paresis of the articulatory muscles - tongue, soft palate, larynx, cheeks and lips;
• reflexes of oral automatism;
• violent laughter and crying;
• buccolingual (buccal-lingual, oral) apraxia;

With stem strokes - clinic bulbar syndrome:

• choking when swallowing saliva, liquid or liquid food, due to the ingress of their particles into the larynx and trachea;
• detection of solid food residues in the buccal pockets, due to paresis of the muscles of the tongue or cheek;
• the ingress of liquid or liquid food into the nose, due to paresis of the muscles of the soft palate;
• difficulty swallowing solid food due to paresis of the constrictor muscles of the pharynx;
• nasolalia-nasal, "nasal" shade of voice, due to incomplete overlapping of the palatine curtain of the entrance to the nasopharyngeal cavity;
• sensation of a lump in the throat;
• dysphonia - a change in the sonority and timbre of the voice, due to paresis of the true vocal cords; the voice becomes hoarse, hoarse, the strength of phonation decreases down to aphonia, with only whispered speech preserved;
• dysarthria caused by peripheral paresis of the muscles of the tongue, soft palate, larynx;
• heart rhythm disturbances in the form of tachycardia, respiratory rhythm;

Developmental symptoms aspiration:

• choking or coughing after swallowing;
• shortness of breath or difficulty breathing, choking after swallowing;
• change in voice quality after swallowing - "wet", "gurgling" voice, hoarseness, temporary loss of voice;
• modified voluntary cough.

More than 2/3 of cases of aspiration are clinically imperceptible and are detected already at the stage of aspiration pneumonia (“silent”, “silent” aspiration).

There are 3 types of aspiration:

1) pre-swallowing - aspiration occurs during chewing food in preparation for swallowing;

2) intraglottic - aspiration occurs when food passes through the pharynx;

3) post-swallowing - aspiration occurs due to the fact that part of the food remains on the back of the pharynx and enters the airways when they open with the first breath after swallowing.

Before starting feeding a patient with a stroke, it is necessary to evaluate the swallowing function. As a result of assessing the predictors of aspiration before and after the water swallowing test, the risk of aspiration is determined: high - in case of detection of two or more predictors and low - in the presence of one predictor; There is no risk of aspiration if these predictors are not identified:

• before the test: dysarthria; dysphonia;
• modified, abnormal cough;
• reduced or absent pharyngeal reflex;
• immediately after swallowing water - cough;
• within 1 minute after swallowing water - a change in voice (they ask to pronounce the sound “a” drawlingly).

Methods for studying swallowing function

• clinical and anamnestic;
• clinical and neurological;
• clinical and instrumental.

Anamnestic method

Information about the violation of swallowing can be obtained by interviewing the patient himself, his relatives or caregivers, as well as from the reports of medical personnel.

It is necessary to pay attention to uncontrolled salivation, leakage of fluid from the mouth, apraxia or poor coordination of the oropharyngeal muscles, weakness of the facial muscles, choking, coughing, shortness of breath or choking attacks during swallowing, difficulty in initiating swallowing, the nature of the food that causes dysphagia, nasal regurgitation, changes in voice quality after swallowing - the appearance of a nasal or "wet" tone of voice, the state of respiratory function at rest.

At the same time, the patient may not complain of swallowing disorder due to impaired awareness of the fact of dysphagia or decreased sensitivity in the oral cavity or in the pharynx, which requires determination of the risk of aspiration using objective tests.

Clinical study of swallowing function

A clinical study consists in conducting a neurological examination in order to establish a topical and clinical diagnosis in general and to determine the state of the swallowing function in particular.

The bedside clinical examination of the act of swallowing is the basis for the examination of the swallowing function. At the same time, the safety of the pharyngeal reflex is not always an indicator of safe swallowing. In almost half of the patients, aspiration is not accompanied by clinically pronounced manifestations - the so-called "silent" aspiration.

Clinical examination of the state of swallowing function includes:

• examination of the soft palate at rest;
• examination of the soft palate during phonation;
• determination of palatine and pharyngeal reflexes;
• performing a swallowing test.

When examining the soft palate at rest, it is necessary to pay attention to the deviation of the palatine uvula from the midline to the healthy side and the sagging of the palatine curtain on the side of the paresis of the muscles of the soft palate.

During phonation, the mobility of the palatine curtain and uvula of the soft palate is determined with the drawn-out pronunciation of the sounds "a" and "e". At the same time, there is an increase in the deviation of the palatine uvula from the midline to the healthy side and a lag or lack of tightening of the palatine curtain on the side of the paresis of the muscles of the soft palate.

Research methodology palatal reflex: with a spatula touch the mucous membrane of the soft palate in turn from two sides symmetrically. Irritation of the mucous membrane of the soft palate causes the palatine curtain to pull up, equally pronounced on both sides. The absence or lag in the tightening of the palatine curtain on one side compared to the opposite indicates paresis or paralysis of the muscles of the soft palate (the "backstage" phenomenon).

Methodology for the study of the pharyngeal reflex: with a spatula touch the mucous membrane of the posterior pharyngeal wall in turn symmetrically on both sides of the midline. Irritation of the mucous membrane of the posterior pharyngeal wall causes swallowing, and sometimes even vomiting or coughing movements. A decrease in the severity or absence of this response on the one hand compared to the opposite indicates paresis or paralysis of the constrictor muscles of the pharynx.

Bilateral absence or symmetrical decrease in the palatine and pharyngeal reflexes may not be associated with an organic brain lesion.

Quite a lot of variations of samples with an assessment of swallowing function have been described and used. If aspiration is suspected, a test swallowing test (an "empty" swallowing test) is performed in the form of swallowing the patient's own saliva. There are other similar tests, when the patient is given a small amount of water in a teaspoon, or a test with 3 teaspoons of water, which offer to drink in turn and after each of them observe the appearance of signs of aspiration (cough, change in sonority of the voice).

If these tests are successful, the swallowing test itself is carried out, which exists in 2 versions: an aqueous swallowing test and a provocative swallowing test.

Methodology for conducting a water swallowing test(The Water Swallowing Test): the patient is asked to swallow 90 ml (variations in different clinics - from 30 to 150 ml) of water from a cup without stopping. The appearance within one minute of this cough or rough "wet" voice indicates the presence of dysphagia.

The swallowing provocative test is a two-stage one, is used less often, and helps to reveal the latent form of dysphagia.

Methodology for conducting a swallowing provocative test(The Water Provocation Test, Swallowing Provocation Test): bolus through a small nasal catheter (internal diameter 0.5 mm) pour 0.4 ml of distilled water into the upper part of the throat, then another 2 ml, which causes involuntary swallowing. Latent time is measured with a stopwatch from the moment the water is introduced to the start of the swallowing movement, which is manifested by a visually observed characteristic laryngeal movement.

In order to objectively confirm dysphagia, a swallowing test with timing of swallowing water is also performed. In the absence of a pharyngeal reflex, it is not possible to fully perform this test, as well as diagnose aspiration.

The method of conducting a swallowing test "for a while": The patient is asked to drink 150 ml of water from a glass as quickly as he can. In this case, the emptying time of the glass and the number of sips are recorded, and then the speed of swallowing and the average volume of a sip are calculated. A swallowing rate below 10 ml/s indicates the presence of dysphagia.

It is possible to supplement the swallowing test with food, when the patient is offered to swallow a small piece of pudding placed on the back of the tongue.

Instrumental methods for assessing dysphagia

Instrumental methods for assessing dysphagia and aspiration in patients with stroke are also quite numerous:

• videofluoroscopy;
• transnasal fibroendoscopy;
• pulse oximetry;
• electromyography of the submental muscle group.

Videofluoroscopy(videofluoroscopy, videofluoroscopy of swallowing with barium) is the gold standard for assessing swallowing, usually performed in a lateral projection, allows you to visualize all phases of swallowing, show the mechanism of dysphagia and identify "silent" aspiration.

Most often, aspiration develops as a result of swallowing dysfunction in the pharyngeal phase, when there is a disorder in the closure of the larynx or paresis of the pharyngeal muscles. The aim of the study is to determine the consistency of food that does not cause dysphagia, and the posture or maneuver that ensures safe swallowing for the patient.

Technique of video fluoroscopy of swallowing: the patient sits at an angle of 45-90 ° and absorbs liquid or food of various consistency, saturated with barium. The total study time is 10-15 minutes. The recording can be saved and played back in slow motion to evaluate swallowing and airway aspiration.

However, the density of barium differs significantly from the density of normal food, and therefore the passage of barium still cannot fully assess the risk of aspiration with conventional products. However, there is no standard protocol for the amount and consistency of barium applied, the videofluoroscopy procedure is relatively complex and time consuming, and it is impossible to examine patients who find it difficult to maintain an upright position.

The non-radiological gold standard for the functional diagnosis of swallowing disorders and the assessment of the morphological causes of dysphagia for the past 25 years has been transnasal fibroendoscopy(naso-endoscopy, fiber-optic endoscopic assessment of swallowing), which allows real-time video monitoring of the act of swallowing and recording a video image for subsequent analysis.

Transnasal fibroendoscopy technique: a naso-endoscope is passed through the nose and placed to the level of the uvula or soft palate in such a way as to provide a view of the pharynx and larynx. The study is safe and can be repeated as often as necessary. As a result, the anatomical features of the pharynx and larynx, the physiology of the act of swallowing, the passage of food from the oral cavity to the pharynx, the presence of aspiration and the response to compensatory maneuvers are evaluated.

The transnasal fibroendoscopy procedure also provides the opportunity to determine the consistency of food that does not cause dysphagia, and the posture or maneuver that ensures safe swallowing for the patient.

Monitoring the degree of blood oxygen saturation during bedside swallowing tests increases the positive predictive value of screening to 95% and allows detection of up to 86% of cases of aspiration while minimizing oral fluid intake - 10 ml of water is sufficient.

Principles of managing a patient with stroke and swallowing disorders

The generally accepted standard of care for a patient with a stroke is a prompt assessment of swallowing function. Screening for dysphagia should be performed as soon as possible after the patient's hospitalization (as soon as the patient's condition permits), before the start of oral medications, fluids, or food, but no later than 24 hours after admission to the hospital.

Monitoring of swallowing disorders should be carried out daily throughout the entire period of hospitalization. Most often, with strokes, swallowing safety is restored within a few days to several weeks (in most cases, within a period of up to 3 months), which is largely due to the functional reorganization of the motor cortex of the undamaged hemisphere. In the future, if dysphagia persists, swallowing disorders are assessed every 2-3 months during the first year, then every 6 months.

The strategy for preventing complications and restoring normal swallowing includes direct and indirect methods.

Direct methods:

• optimization of the position of a patient with a stroke during a meal;
• modification of the consistency of food and drinks;
• safe swallowing rules;
• compensatory techniques during swallowing.

Indirect methods:

• rehabilitation oropharyngeal exercises;
• stimulation of the structures of the oral cavity and pharynx:
• transcutaneous and intrapharyngeal electrical stimulation;
• thermal tactile stimulation;
• transcranial magnetic stimulation of motor projection zones of the oral cavity and pharynx;
• acupuncture;
• behavioral therapy.

Screening tests

Screening tests are aimed at early bedside assessment of dysphagia and can be performed by paramedics on a stroke team. The purpose of the survey is to:

• assessing the level of consciousness of the patient and his ability to take part in the examination, as well as assessing the degree of postural control (the ability to sit in an upright position on his own or with support), which generally determines the possibility of oral feeding;
• monitoring of oral hygiene and the degree of control of oral secretion;
• observation of manifestations of violations of the oropharyngeal phase of swallowing (shortness of breath, cough, "wet" voice);
• assessment of the patient's voice quality, muscle function and sensitivity of the oral cavity and the initial parts of the pharynx, the ability to cough;
• if necessary, water swallow tests (to assess aspiration risk).

Examples of screening tests used in world practice:

• Massey Bedside Swallow Screen (2002);
• Timed Test of Swallowing and Questionnaire (1998);
• Screening Tool for Acute Neurological Dysphagia (STAND) (2007);
• Standardized Swallowing Assessment (SSA) (1993, 1996,1997,2001);
• Gugging Swallowing Screen (GSS) (2007);
• Toronto Bedside Swallowing Screening Test (TOR-BSST) (2009);
• Bames-Jewish Hospital Stroke Dysphagia Screen (BJH-SDS) (2014).

A single test that is generally accepted for all clinics is not defined, however, the GSS and TOR-BSST tests showed the highest sensitivity and specificity. At the same time, the use of 8 or 10 teaspoons of water in the test increases the sensitivity of the TOR-BSST test from 79% when using 5 spoons to 92% and 96% when using 8 or 10 spoons, respectively.

In a comparative study with videofluoroscopy, the BJH-SDS screening test showed a sensitivity and specificity for detecting dysphagia of 94 and 66%, respectively, and for detecting aspiration, 90 and 50%.

If signs of dysphagia are detected as a result of screening, a full assessment of swallowing is then performed using the ASHA test to clarify the causes, nature (which phase of swallowing is disturbed) and severity of violations. At the same time, the assessment includes a detailed control of the swallowing phases, the motor and sensory status of the oral cavity, and anamnesis data analysis. If necessary, an instrumental study of the swallowing function is prescribed.

Nutrition control and feeding rules for a patient with dysphagia

It is necessary to control the consistency and volume of food in order to improve the transit of the food bolus. It is standard practice to change the consistency of food and liquid (a change to soft food and thick liquid is necessary), as well as the prohibition of food intake by mouth for the most severely ill patients. However, if possible, oral feeding is preferred.

For the prevention of aspiration in patients with swallowing disorders, the correct organization of the feeding process and the selection of food consistency are necessary. At the same time, there is no single diet for dysphagia. Standards for the modification of solid and liquid foods in patients with stroke and swallowing disorders vary from country to country.

Rules for feeding patients with strokes with swallowing disorders:

• patients with existing aspiration should start eating only after receiving instructions to prevent aspiration;
• a thorough revision of the oral cavity is necessary before eating (to remove accumulated bacteria from the oral mucosa) and after the end of feeding (the remaining food can be aspirated);
• need to control the need to use dentures; teeth and dentures should be cleaned at least 2 times a day to ensure that the oral cavity is clean;
• feeding should be carried out only in a sitting position (torso at an angle of 90 °), with support under the back, if necessary, the patient can be supported with pillows; you can not feed a lying patient;
• eating should be done in a relaxed atmosphere. The patient should eat slowly and without being distracted by conversations, TV, radio;
• it is necessary to observe the symptoms of dysphagia during meals and within 30 minutes after eating; while within 30-60 minutes, the patient's body position should be maintained vertical or close to it to ensure esophageal clearance and gastric secretion and reduce reflux;
• the feeder should be at the level of the patient's eyes;
• at the same time, only a small amount of food can be given, the frequency of intake must be increased;
• when feeding, food is laid on the unaffected side in small portions;
• during feeding, it is necessary to ensure the inclination of the head anteriorly, it is impossible to tilt the patient's head backwards;
• feeding is carried out with a teaspoon and at a low speed (patients with right hemispheric strokes are impulsive and tend to swallow too fast);
• it is not recommended to use tablespoons and spoons made of plastic in patients with an increased bite reflex;
• it is necessary to teach the patient to take food and bring it to the mouth with a hand or with both hands at once. If he can use a spoon for eating, you need to make the handle of the spoon thicker - this will make it easier to hold it (you can use a piece of rubber hose or make a handle out of wood);
• at the moment of swallowing food, it is necessary to turn the head in the direction of the lesion - towards the paretic muscles of the pharynx or tongue;
• it is necessary to make sure that swallowing is completed before offering the next portion;
• if the patient cannot absorb liquid, you need to teach him to drink from a spoon; safe swallowing from a wide cup or glass is encouraged;
• to stimulate swallowing, a drinking straw or drinking cup with a long spout can be used, which prevents the head from tilting backwards and thus reduces the risk of aspiration;
• it is necessary to teach the patient to bring food or liquid to the middle of the mouth, and not to the side, and to take food into the mouth using the lips, not the teeth;
• it is necessary to teach the patient to keep his lips closed and his mouth closed when he chews or swallows food. If the lower lip hangs down, the patient should be taught to support it with the fingers;
• after eating, you need to make sure that no pieces of food remain in your mouth - you need to rinse your mouth or clean your mouth with a napkin. If the patient choked, it is necessary to give the opportunity to cough up, while drinking should not be, since the liquid easily penetrates the respiratory tract.

food requirements when feeding patients with strokes with swallowing disorders:

• food should look appetizing;
• adding citric acid to food improves the swallowing reflex by improving taste and acid stimulation;
• food should be warm enough, as patients with dysphagia need a long time to eat it. If the patient does not feel warm food in the mouth, food should be fed at room temperature;
• solid and liquid food should be offered at different times, drinks should be given before or after meals;
• semi-rigid foods are best tolerated: casserole, thick yogurt, mashed vegetables and fruits, watery cereals, jelly, soufflé, meatballs;
• it is necessary to select the consistency of food (soft food, thick puree, liquid puree) and liquid (consistency of mousse, yogurt, thick jelly, syrup, water). In all liquids, it is recommended to add thickeners, such as starch or edible gelatin. It should be remembered that with more liquid food or drink it is more difficult to take a safe (without aspiration) sip. Soups or solid foods can be brought to a homogeneous mass using a blender or mixer;
• dried fruits and sour-milk products (kefir, yogurt) are recommended, especially for bedridden patients with a tendency to constipation;
• it is recommended to provide the patient with a sufficient amount of potassium salts (dried apricots, raisins, cabbage, potatoes, figs) and magnesium (buckwheat and oatmeal cereals);
• it is necessary to exclude from the diet foods that often cause aspiration - a liquid of normal consistency (water, juices, tea), or easily crumbling - bread, cookies, nuts;
• meat pieces and citrus fruits, the fibers of which are hard to chew, are not recommended;
• it is not recommended to mix food and drinks in one go - it is advisable to drink before or after a meal.

In general, a special diet includes 4 different consistencies: dense liquid, pureed, crushed and soft minced food. With a soft diet, all hard, small and fibrous food particles are excluded. At the same time, meat can have 3 consistencies: chopped, chopped and ground.

chopped food is actually semi-rigid and is preferred over puree as it has more fibrous structures to encourage swallowing.

pureed food It has the consistency of a pudding and is usually easier to swallow than a more conventional diet because it is thick enough to form a food bolus, stimulates the sensitivity of the oral mucosa and improves the ability to swallow. At the same time, when feeding pureed food, there is also a risk of aspiration.

Patients receiving thick liquids have a lower risk of developing aspiration compared to those who received food of a liquid consistency.

There are 4 types of liquid consistency:

• mousse consistency (liquid is held on a fork);
• the consistency of yogurt (liquid flows from the fork in large drops);
• the consistency of the syrup (liquid envelops the fork, but quickly drains from it);
• the consistency of water (liquid immediately drains from the fork).

In the acute period of a stroke, the consistency of the liquids is selected depending on the capabilities of the patient. In this case, at first it is preferable to use a thick liquid for feeding (mousse, yogurt, jelly, kefir), which is much easier to swallow than water, since it passes more slowly through the oropharynx and thus leaves more time to prepare for the start of swallowing.

Then gradually, as the function of swallowing is restored, they move to more fluid liquids. Before the patient restores the function of swallowing, it is necessary to avoid liquids of the usual consistency (water, juices, tea, milk). If the patient is very difficult to swallow liquids, you can add liquid to solid food and bring the food to the consistency of liquid puree. It is not recommended to use dry food - bread, cookies, crackers, nuts.

Due to the fact that in general patients with stroke consume insufficient amounts of fluid and are characterized by dehydration, especially patients with aspiration detected during videofluoroscopy, receiving thick liquids and taking diuretics, it is necessary to take a sufficient amount of fluid during the day.

Compensatory techniques

• changing the position of the head (turning towards the lesion - towards the paretic muscles of the pharynx or tongue) to reduce the likelihood of aspiration;
• bending the chin to the sternum before the moment of swallowing food, which helps to juxtapose the epiglottis and the aryepiglottic fold and leads to the closure of the airways during swallowing;
• in addition to this technique, simultaneous anterior tilt of the torso is possible;
• double swallowing - the implementation of a repeated swallowing movement in order to minimize reflux after swallowing and prevent new aspiration;
• cough after swallowing - the implementation of coughing movements after swallowing food in order to prevent aspiration.

Rehabilitation exercises

• Reception Shaker- in the supine position, raise your head for a few seconds, repeating this 20 times. Helps to improve the opening of the upper esophageal sphincter by strengthening the suprahyoid muscle and thereby reducing food debris in the pharynx after swallowing;

• reception of Mendelssohn- prolonged contraction of the suprahyoid muscles in order to ensure the rise of the larynx, the opening of the upper esophageal sphincter and the closure of the airways;

• touch the tip of the tongue to the soft palate with an open mouth, and then with a closed one (6-8 times);
• firmly holding the tip of the tongue with your teeth, make a swallowing movement (tension in the throat and difficulty at the beginning of swallowing should be felt);
• swallowing a drop of water from a pipette;
• if possible: swallowing saliva, drops of water, juice, or simply imitation of swallowing movements (perform the exercise only after consulting a doctor);

• imitation of familiar movements (6-8 times): chewing; coughing; vomiting movements; yawning with wide open mouth, noisily drawing in air; yawning with a closed mouth; the image of a whistle without sound, straining the oral cavity; gargling; snoring on inhalation and exhalation (imitation of a sleeping person); chewing and swallowing semolina; swallowing a large piece; inflate your cheeks strongly and hold them in this state for 5-6 seconds;

• pronunciation of sounds (6-8 times): firmly pronounce the vowel sounds “a”, “e”, “i”, “o”, “u”; alternately repeat the sounds "and / y". The pharyngeal muscles should tense up; firmly pronounce the sounds "a" and "e" (as if pushing); sticking out the tongue, imitate the sound "g"; silently pronounce the sound "y", pushing forward the lower jaw; how long does it take to exhale to draw the sound “m”, closing your lips; tapping your fingers on the larynx on one exhale, pull the sound “and” either low or high; pronounce several times, holding the tip of the protruding tongue with your fingers, the sounds “and / a” (separated by a pause); stick out your tongue and, without removing it, pronounce the sound "g" five times.

New therapeutic methods are neuromuscular electrical stimulation of the pharyngeal muscles (transcutaneous and intrapharyngeal), transcranial magnetic stimulation and the biofeedback method.

The use of electrical stimulation of the pharyngeal muscles makes it possible to increase the probability of a pronounced clinical improvement in swallowing function by more than 5 times and the probability of swallowing function recovery by more than 3 times with a 30% decrease in aspiration manifestations and a 5-fold decrease in the risk of aspiration complications. Acupuncture and behavioral therapy also statistically significantly contribute to the reduction of manifestations of dysphagia.

Transcranial magnetic stimulation for 20 minutes a day for 5 days improved swallowing reaction time, reduced the number of aspirations of liquid and food debris, but had no effect on oropharyngeal transit time and laryngeal closure.

Enteral nutrition

Enteral methods include feeding by nasogastric tube or percutaneous endoscopic gastrostomy. Parenteral nutrition is used if it is impossible to use enteral nutrition - if the latter is contraindicated or intolerant, and should be limited in time.

Early feeding through a nasogastric tube improves the survival of patients; therefore, insertion of the tube in the first 48 hours after the onset of a stroke is recommended. However, tube feeding only partially reduces the risk of developing pneumonia, which is associated with a rich content of microorganisms in the oral cavity; any violations of normal nutrition at the same time contribute to the development of infections of the lower respiratory tract.

The nasogastric tube is easy to install, but also easily clogged, and can easily be intentionally removed by the patient himself or unintentionally removed in case of poor attachment, when washing, dressing the patient or during any other movements, during vomiting. In general, displacement of the nasogastric tube occurs in 58-100% of patients.

Removal of the nasogastric tube may be earlier in patients with hemispheric stroke compared with patients with brainstem damage, who are younger, with a mild onset of the disease and with a better recovery of the functional state.

If it is not possible to restore safe swallowing in the short term (within 3-4 weeks), it is necessary to organize enteral nutrition by percutaneous endoscopic gastrostomy (preferably over surgical), which can be delayed for several weeks.

There is evidence of a 5-fold reduction in mortality within 6 weeks with percutaneous endoscopic gastrostomy feeding compared with feeding through a nasogastric tube, which is associated with the use of small portions of food. When long-term nutritional support (more than one month) is needed, percutaneous endoscopic gastrostomy is also preferred over a nasogastric tube because it is more convenient.

In patients with a reduced pharyngeal reflex, it is possible to use periodic oropharyngeal feeding, in which, before each meal, the probe is inserted into the pharynx through the mouth, portions of food and nutritional supplements are administered at a rate of no more than 50 ml / min, after which the probe is removed and washed with water.

For enteral nutrition, special enteral hypercaloric polysubstrate balanced mixtures are used at the rate of 2200-3000 kcal/day. Apply a mixture of Nutrison, Nutrison Energy, Nutricomp ADN standard, in patients with diabetes - Nutricomp ADN fiber and others - 500-2000 ml / day (25-150 ml / h).

Enteral mixtures can be administered as the sole route of feeding through a tube, as well as mixed enteral-oral or enteral-parenteral nutrition. In this case, you can drink the mixture through a straw or pour it into a glass, like drinking yogurt.

Total parenteral nutrition is an intravenous injection of 500-1000 ml of a 10-15% solution of amino acids (Infezol 40 and Infezol 100), 1000 ml of a 20% glucose solution and 500 ml of a 20% solution of a 2-3rd generation fat emulsion (Lipofundin, Medialipid, Stmctolipid and LipoPlus, SMOF Lipid, respectively). At the same time, glucose and glucose-containing solutions can be administered no earlier than 7-10 days after the patient's admission, provided that blood glucose levels are stable (no more than 10 mmol/l).

All-in-one parenteral nutrition systems (kabiven, oliclinomel, nutricomp lipid) are more technologically advanced. At the same time, one container, which is a three-section bag, contains solutions of amino acids, glucose and fat emulsions in various combinations and may include electrolytes. This technology ensures the use of one infusion set and one infusion pump and a stable rate of content administration.

Antibiotic therapy

The prophylactic prescription of antibacterial drugs in patients with strokes is unacceptable, since it causes suppression of the growth of endogenous microorganisms sensitive to them and reproduction of resistant ones, which in the future will require the use of more expensive antibiotics.

• an increase in body temperature over 37 ° C;
• weakened breathing during auscultation of the lungs and the appearance of shortness of breath;
• coughing disorder;
• bladder catheterization;
• bedsore formation.

Taking into account the largest proportion of gram-negative microflora, staphylococcus and anaerobic bacteria in the etiology of nosocomial pneumonia in patients with severe forms of stroke, at the first signs of pneumonia, before obtaining the results of determining sensitivity to antibiotics, broad-spectrum antibiotics - cephalosporins of the I-IV generation (in combination with aminoglycosides) should be prescribed or fluoroquinolones II-IV generation (ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin), often in combination with metronidazole or modern macrolides.

Due to the high oto- and nephrotoxicity of first-generation aminoglycosides, second-generation drugs are used. Gentamicin and tobramycin are prescribed at 3-5 mg / kg / day in 1-2 injections parenterally. The reserve drug can be the third-generation aminoglycoside amikacin, which is administered at 15-20 mg/kg/day in 1-2 injections. At the same time, aminoglycosides are not effective against pneumococcus and are inferior to other effective antistaphylococcal antibiotics as more toxic.

Monotherapy with carbapenems is possible: imipenem - 0.25-1 g every 6 hours (up to 4 g / day), meropenem - 0.5-2 g every 8-12 hours.

Perhaps the combined use of combined protected antipseudomonal ureidopenicillins (ticarcillin / clavulanic acid, piperacillin / tazobactam) with amikacin.

In most cases, with an adequate choice of antibiotics, the duration of antibiotic therapy is 7-10 days. With atypical pneumonia or staphylococcal etiology, the duration of treatment increases. For pneumonia caused by gram-negative enterobacteria or Pseudomonas aeruginosa, treatment should continue for at least 21-42 days.

Food sampling occurs due to receptors in the oral and nasal cavities.

Chewing - due to the teeth and tongue.

Saliva is secreted by three pairs of large salivary glands and many small ones located in the epithelium of the oral cavity. During the day, 0.5-2.0 liters of saliva is secreted. Saliva contains 99% water and 1% other substances:

• mucin is a slimy protein that sticks together the food bolus
• amylase - breaks down starch into maltose
• sodium bicarbonate - creates an alkaline environment for amylase to work
• lysozyme - antibiotic

Unconditioned reflex salivation occurs when the receptors of the oral cavity are irritated. Conditioned reflex - at the sight or smell of familiar food, thoughts about food, the onset of mealtime, etc.

When swallowing, food passes through the pharynx:

• the soft palate rises, closing the passage to the nasal cavity
• the epiglottis descends, closing the passage to the larynx.

From the pharynx, food enters the esophagus. Its walls secrete mucus and make peristaltic contractions.

1. What is the function of saliva enzymes in digestion?
A) coordinate the activity of the digestive organs
B) break down fats into fatty acids and glycerol
B) convert starch to glucose
D) determine the physical properties of food

2. The swallowing reflex is triggered when food
A) on the tip of the tongue
B) hits the root of the tongue
B) touches the lips
D) passed mechanical grinding

3. What process is shown in the picture?

A) swallowing
B) cough
B) sneezing
D) vomiting

4. Saliva contains enzymes involved in the breakdown
A) carbohydrates
B) hormones
B) proteins
D) fat

5. What substance begins to break down under the action of enzymes in the human oral cavity?
A) starch
B) DNA
B) fat
D) protein

Swallowing reflex. Vomiting reflex.

Arbatsky Mikhail, 07/24/2015

The swallowing reflex is a complex unconditioned chain reflex with voluntary control of the first phase.

• In the process of moving the food bolus from the oral cavity to the esophagus, the receptors of the root of the tongue, soft palate, pharynx and esophagus are sequentially stimulated.

  Neurological disorders of the pharynx. Causes. Symptoms. Diagnostics. Treatment

  The impulse along the sensitive fibers of the IX and X cranial nerves enters the swallowing center.

• The swallowing center, located in the medulla oblongata and the bridge, includes the sensory nucleus of the solitary pathway and the double (motor) nucleus of the IX, X nerves, the adjacent zones of the reticular formation. This center functionally unites the neurons of about two dozen nuclei of the trunk, cervical and thoracic segments of the spinal cord.
• As a result, a strictly coordinated sequence of contraction of the muscles involved in the act of swallowing is provided: maxillofacial, tongue, soft palate, pharynx, larynx, epiglottis and esophagus.
• The swallowing center is functionally connected with the centers of chewing and breathing: the swallowing reflex stops the act of chewing and breathing (usually in the inhalation phase).

The gag reflex is the involuntary ejection of the contents of the digestive tract, predominantly through the mouth. It occurs when the receptors of the root of the tongue, pharynx, stomach, intestines, peritoneum, vestibular apparatus, and the immediate vomiting center are irritated.

• Afferent impulses enter the centers of vomiting mainly along the sensory fibers of the IX, X, and VIII (vestibular part) nerves.
• The center of vomiting is located in the dorsal part of the reticular formation of the medulla oblongata, its neurons have M- and H-cholinergic receptors. The vomiting center is regulated by the chemoreceptor trigger zone of the bottom of the IV ventricle, which is outside the blood-brain barrier, its neurons have D2 (dopamine) -, 5-HT (serotonin) -, H (histamine) receptors, the stimulation of which by blood substances (for example, apomorphine ) causes vomiting (blockade of the above receptors with drugs suppresses the gag reflex).
• Efferent impulses from the vomiting center come through the vagus and splanchnic nerves to the stomach (pylorus contraction, bottom relaxation), esophagus (sphincter relaxation), small intestine (increased tone, antiperistalsis), and through motor spinal centers through somatic nerves to the diaphragm and abdominal muscles. walls, the contraction of which leads to the expulsion of the contents of the stomach (in this case, the soft palate rises, the glottis closes).
• Vomiting is accompanied by a decrease and deepening of breathing, increased salivation, tachycardia.

Laryngo-pharyngeal symptoms

J.Terracol (1927, 1929), describing these disorders in patients with degenerative lesions of the cervical spine, unsuccessfully called them pharyngeal migraine. Patients experience a tingling sensation in the throat, goosebumps, itching, a sensation of a foreign body in combination with glossodynia - sore throat. Cough, swallowing disorders - dysphagia, as well as taste perversions are noted. The gag reflex may decrease. Patients also complain of choking or a dry cough, especially during periods of increased neck pain. (Tykochshskaya E.D., 1935). In 1938, W. Reid noted dysphagia in a patient with a cervical rib, swallowing became normal after the rib was removed. According to H. Julse (1991), cervical dysphagia is possible with blockade of the C|.c joint. Possible muscular-tonic reaction of the upper cervical muscles - giomandibular, as well as muscles innervated from the segment

Orthopedic neurology. Syndromology

Rice. 5.18. Scheme of some connections of the cervical sympathetic nodes: 1 - upper cervical node; 2 - upper cardiac nerve; 3 - the middle cervical node and branches descending down, forming the subclavian loop of Viesen; 4 - middle cardiac nerve; 5 - lower cardiac nerve; 6 - the lower cervical (stellate) node and the vertebral nerve rising upward; 7 - vertebral artery; 8 - gray connecting branch; X - vagus nerve; XII - hypoglossal nerve.

cops С2-С3: sternohyoideus, omohyoideus, sternothyreoideus, cricothyreoideus, thyreopharyngeus, constrictor pharyngis posterior. J.Euziere (1952) objectively established hypoesthesia of the pharynx, decreased pharyngeal reflex, atrophy and dryness of the mucosa, pallor of the tonsils. Among the sick With"Cervico-brachial pain" R. Weissenbach and P. Pizon (1952, 1956) noted pharyngeal symptoms in 1.6%, while D. Bente et al. (1953) - in 37%. Morrison (1955) emphasized that this syndrome often gives rise to an unreasonable suspicion of cancer. The pathogenesis of the syndrome remains unclear. It is assumed that anastomoses between the cervical and IX-X nerves play a role.

‘The branches of the CGS2 spinal nerves anastomose with the hypoglossal nerve at the level of its arch. descending branch

The hypoglossal nerve, descending along the anterior-outer surface of the carotid artery, innervates the small muscles below the hyoid bone. At a different level of the common carotid artery, this branch connects with the branches of the cervical plexus (from the Q-Cr nerves) - the hyoid loop. The descending branch of the hypoglossal nerve is sometimes called n. cervicalis descendens superior(and the hyoid loop - n. cervica / is descendens inferior)-rice. 5.18.

We observed a patient with hypermobility of the upper cervical spine, who from time to time had paresthesias in the C2 zone on the scalp. They appeared naturally simultaneously with a sensation of sore throat, which the patient (doctor) associated with an exacerbation of chronic tonsillitis. Within the boundaries of paresthesia, hyperpathy was clearly defined against the background of mild hypoalgesia. There are also connections of the cervical nerves with the larynx and pharynx through the sympathetic nervous system. (Morrison L., 1955; Tchaikovsky M.N., 1967). A.D. Dinaburg and A.E. Rubasheva (1960) noted in some cases aphonia, which they attribute to the connections of the stellate ganglion with the recurrent nerve. N. Sprung (1956) associated dysphonia with damage to the phrenic nerve, Z. Kunc (1958) emphasizes the proximity of the paths of the third branch of the trigeminal nerve to the fibers of pain sensitivity of the IX and X nerves descending into the spinal cord, and does not exclude the connection of pain in throat with spinal disorders of the upper cervical level. Here it is appropriate to recall the possible compression of the glossopharyngeal nerve, as in thrombosis of the vertebral artery. (Pope F., 1899), as well as her aneurysm (Brichaye J. eta!., 1956).

Because in some patients with dysphagia, anterior growths of the vertebral bodies were found, the possibility of pressure of these exostoses on the esophagus is allowed (Grinevich D.A., 1941; Borax J., 1947; Ruderman A.M., 1957; Popelyansky Ya.Yu., 1963).

What diseases cause dysphagia (difficulty swallowing)?

According to the results of X-ray kymographic studies, L.E. Keves (1966) believes that the matter is rather not a mechanical obstacle, but slow or incomplete relaxation of the cricopharyngeal sphincter, which is the only antagonist (constantly tense) in the swallowing apparatus. Non-opening of the food inlet (achalasia) is surgically removed by cutting this muscle (Kaplan C, 1951; Abakumov I.M. and Lavrova SV., 1991). The muscle is innervated by the IX, X cranial nerves and the superior cervical plexus. L.E.Kevesh (1966) believed that these changes, as well as the waviness of the posterior contour of the pharynx, are associated with reflex segmental contractions of the esophagus. Dysphonia, pain and soreness of overstressed muscles, relaxation of the vocal fold on the side of the predominant manifestations of cervical osteochondrosis were observed in patients with hypertonicity of the upper muscle group of the thyroid cartilage. With predominant hypertonicity of the lower muscle group, on the contrary, the tension of the vocal fold is noted (Alimetov Kh.A., 1994)1. Some cases of hysterical lump in the throat are trying to be associated with cervicogenic laryngeal-pharyngeal dysfunction. (Morrison L., 1955).

It should be recognized that in many of the described observations, there is no convincing evidence of the pathogenetic connection of pharyngeal and laryngeal disorders with cervical osteochondrosis. We did not observe any increase or decrease in

1 The tension of the vocal cord varies with the degree of tilt of the thyroid cartilage, which is raised by the thyroid-hyoid and thyro-pharyngeal muscles and lowered by the sternothyroid and thyro- cricoid muscles. Discoordination of these muscles, innervated from the upper cervical segments (anastomoses to the descending branch of the hypoglossal nerve), is manifested by changes and dysesthesias in this area.

Chapter V. Syndromes of cervical osteochondrosis

stretching according to Bertschi, there were no convincing examples of parallelism in the course of these disorders in relation to other symptoms of cervical osteochondrosis. Therefore, we believe that a high percentage (37%) of "functional swallowing disorders" given by D. Bente et al. (1953) and other authors, belongs to the category of hobbies and requires further control. Interestingly, W.Bartschi-Rochaix (1949), who studied craniocerebral disorders in cervical osteochondrosis more scrupulously than other authors, did not find any of the 33 patients with disorders of the pharynx or larynx. He believed that the intactness of this area is associated with the specifics of the vertebral artery syndrome of traumatic origin. We (1963), like K.M. Bernovsky and Ya.M. Sipuhin (1966), noted these disorders on average 3% and made sure that among patients with cervical osteochondrosis of non-traumatic genesis, laryngeal-pharyngeal syndromes are an uncharacteristic manifestation if the patient does not have a tendency to senestopathic experiences. So, in one patient, along with other manifestations of autonomic dysfunction, there were unpleasant sensations of “pulling” the root of the tongue into the depths, it became uncomfortable for her to swallow (“something interferes”). Such phenomena were sometimes combined with anxiety, hypochondria, hysterical mood.

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How to restore the swallowing reflex

The causes of a violation of the swallowing reflex can come from different systems: nervous, digestive, etc. In addition, you can not rush a person who has had a stroke, because the swallowing reflex takes time to recover. In addition, the swallowing reflex is regulated by the central nervous system. In addition, a characteristic symptom of a violation of the swallowing reflex is increased salivation and a feeling of suffocation.

The swallowing reflex is a very complex, always bilateral coordinated act, in which a large number of muscles are involved, contracting strictly in concert and in a certain sequence.

Dysphagia - difficulty swallowing associated with slowness or impaired swallowing movements. Various pathologies of the vocal cords, including paralysis of the larynx; atrophy of the vocal cords; paresis of the vocal cords; Congenital pathologies of development, including the absence of a swallowing reflex.

How to restore the pharyngeal reflex

However, sometimes swallowing can be disturbed. Various muscles take part in the act of swallowing: mouth, tongue, pharynx and esophagus. Thanks to this, a person can take a sip when he sees fit, that is, he can do this action arbitrarily. After that, the muscles of the pharynx contract, and the lump passes into the esophagus without entering the trachea. However, most often, swallowing disorders, or dysphagia, appear due to disorders in the central nervous system.

In addition, patients choke on food, which leads to throwing it into the respiratory tract. This, in turn, can lead to the development of pneumonia. Functional - associated with a violation of peristalsis and relaxation of the muscles of the pharynx and esophagus. Sometimes swallowing disorders can be caused not only by diseases, but also by psychological disorders. Treatment in this case is carried out not only with strict adherence to diet and posture when eating, but also with the passage of psychotherapy.

All about diseases of the nervous system, symptoms, causes and methods of treatment. Swallowing is one of those processes that you hardly notice at all - until they are disturbed. Swallowing large chunks of food can also lead to swallowing problems. Approximately 50% of people with swallowing disorders have experienced a stroke. If the violation of swallowing is aggravated and the symptoms increase for several months, then this is typical for cancer of the esophagus.

You need to be very careful about your overall health. People do not pay enough attention to the symptoms of diseases and do not realize that these diseases can be life-threatening. The pause between swallowing and contraction of the esophagus is the longer, the greater the number of previous swallows.

How and why can swallowing be disturbed?

After each sip, wait for an involuntary cough or ask the patient to talk; coughing or changes in the patient's voice (i.e., "wet" voice) may indicate aspiration.

Metabolic disorders, which can sometimes resemble a stroke, are common in patients with severe strokes. One study suggested that hyponatremia is more common in hemorrhages than ischemic strokes, but this remains controversial.

However, in 50% of patients with an increase in blood sugar levels, the HBA1c level was normal, which indicates that hyperglycemia has occurred recently and may be directly related to stroke. Whether hyperglycemia is associated with the release of corticosteroids and catecholamines as a result of the stress response is controversial.

Their actions are clearly coordinated, so the food or liquid that a person consumes can only enter the stomach. At the slightest sign of difficulty swallowing, you should immediately seek help. The first manifestations of dysphagia make themselves felt by the patient with pain that occurs at the time of swallowing.

Often, the patient may make an additional complaint of heartburn, discomfort in the solar plexus area, or a lump in the esophagus. In this regard, treatment should be carried out in combination with the underlying disease. If the problem lies in disorders of the gastrointestinal tract, then drug treatment is usually prescribed. No less often, dysphagia appears in patients after a stroke.

Delayed triggering of the swallowing reflex is the most common mechanism, but most patients may have more than one pathology. The swallowing reflex is even more constant than the sucking reflex, and may be absent only in children with very gross defects in the development of the central nervous system. Violation of the swallowing reflex leads to rapid depletion of the body due to the fact that the latter does not receive enough nutrients.

Chewing ends with swallowing - the transition of the food bolus from the oral cavity to the stomach. Swallowing occurs as a result of irritation of the sensitive nerve endings of the trigeminal, laryngeal and glossopharyngeal nerves. Through the afferent fibers of these nerves, impulses enter the medulla oblongata, where swallowing center. From it, impulses along the efferent motor fibers of the trigeminal, glossopharyngeal, hypoglossal and vagus nerves reach the muscles that provide swallowing. Evidence of the reflex nature of swallowing is that if you treat the root of the tongue and throat with a cocaine solution and “turn off” their receptors in this way, then swallowing will not take place. The activity of the bulbar swallowing center is coordinated by the motor centers of the midbrain, the cerebral cortex. The boulevard center is in close connection with the center of respiration, inhibiting it during swallowing, which prevents food from entering the airways.

The swallowing reflex consists of three successive phases: I-oral (voluntary); II-pharyngeal (fast, short involuntary); III - esophageal (slow, prolonged involuntary).

During phase I, a 5-15 cm bolus of food is formed in the mouth from the chewed food mass; movements of the tongue, he moves to his back. With arbitrary contractions in front of it, and then in the middle part of the tongue, the food lump is pressed against the hard palate and transferred to the root of the tongue by the anterior arches.

During phase II, stimulation of the tongue root receptors reflexively causes contraction of the muscles that lift the soft palate, which prevents food from entering the nasal cavity. With the movements of the tongue, the food bolus is pushed into the throat. At the same time, there is a contraction of the muscles that displace the hyoid bone and cause the larynx to rise, as a result of which the entrance to the respiratory tract is closed, which prevents food from entering them.

DIGESTIVE SYSTEM Test

The transfer of the food bolus into the pharynx is facilitated by an increase in pressure in the oral cavity and a decrease in pressure in the pharynx. They prevent the reverse movement of food into the oral cavity by the raised root of the tongue and the arches tightly adjacent to it. Following the entry of the food bolus into the pharynx, the muscles contract, narrowing its lumen above the food bolus, as a result of which it moves into the esophagus. This is facilitated by the pressure difference in the cavities of the pharynx and esophagus.

Before swallowing, the pharyngeal-esophageal sphincter is closed; during swallowing, the pressure in the pharynx rises to 45 mm Hg. Art., the sphincter opens, and the food bolus enters the beginning of the food water, where the pressure is not more than 30 mm Hg. Art. The first two phases of the act of swallowing last about 1 s. Phase II swallowing cannot be performed voluntarily if there is no food, liquid or saliva in the oral cavity. If the root of the tongue is mechanically irritated, swallowing will occur, which cannot be arbitrarily stopped. In phase II, the entrance to the larynx is closed, which prevents the reverse movement of food and its entry into the airways.

Phase III of swallowing consists of the passage of food through the esophagus and its transfer to the stomach by contractions of the esophagus. Movements of the esophagus-water are caused reflexively with each act of swallowing. The duration of phase III when swallowing solid food is 8-9 s, liquid 1-2 s. At the moment of swallowing, the esophagus is pulled up to the pharynx and its initial part expands, taking the food bolus. The contractions of the esophagus have a wave character, occur in its upper part and spread towards the stomach. This type of abbreviation is called peristaltic. At the same time, the ring-shaped muscles of the esophagus contract sequentially, moving the food bolus with a constriction. A wave of reduced tone of the esophagus (relaxation) moves in front of it. The speed of its movement is somewhat greater than the contraction wave, and it reaches the stomach in 1-2 s.

The primary peristaltic wave, caused by the act of swallowing, reaches the stomach. At the level of intersection of the esophagus with the aortic arch, a secondary wave occurs, caused by the primary wave. The secondary wave also propels the food bolus to the cardia of the stomach. The average speed of its distribution through the esophagus 2 -5 cm / s, the wave covers a section of the esophagus 10-30 cm long in 3-7 s. The parameters of the peristaltic wave depend on the properties of the food being swallowed. The secondary peristaltic wave can be caused by the remnant of the food bolus in the lower third of the esophagus, due to which it is transferred to the stomach. Peristalsis of the esophagus ensures swallowing without the assistance of gravitational forces (for example, in a horizontal position of the body or upside down, as well as in conditions of weightlessness in astronauts).

Liquid intake causes swallowing, which in turn forms a relaxation wave, and the liquid is transferred from the esophagus to the stomach not due to its propulsive contraction, but with the help of gravitational forces and an increase in pressure in the oral cavity. Only the last sip of liquid ends with the passage of a propulsive wave through the esophagus.

The regulation of esophageal motility is carried out mainly by efferent fibers of the vagus and sympathetic nerves; an important role is played by its intramural nervous system.

Outside of swallowing, the entrance from the esophagus to the stomach is closed by the lower esophageal sphincter. When the relaxation wave reaches the end of the esophagus, the sphincter relaxes and the peristaltic wave carries the food bolus through it into the stomach. When the stomach is full, the tone of the cardia increases, which prevents the contents of the stomach from being thrown into the esophagus. parasympathetic fibers vagus nerve stimulate the peristalsis of the esophagus and relax the cardia, sympathetic fibers inhibit the motility of the esophagus and increase the tone of the cardia. One-way movement of food contributes to the acute angle of the confluence of the esophagus into the stomach. The sharpness of the angle increases with the filling of the stomach. The valvular role is played by the labial fold of the mucous membrane at the junction of the esophagus into the stomach, contraction of the oblique muscle fibers of the stomach and the diaphragmatic esophageal ligament.

In some pathological conditions, the tone of the cardia decreases, the peristalsis of the esophagus is disturbed, and the contents of the stomach can be thrown into the esophagus. This causes an unpleasant sensation called heartburn. Swallowing disorder is aerophagia- excessive swallowing of air, which excessively increases intragastric pressure, and the person experiences discomfort. Air is pushed out of the stomach and esophagus, often with a characteristic sound (regurgitation).

Swallowing disorders: causes, "coma in the throat" syndrome

The process of swallowing is repeated periodically, not only in the state of wakefulness, but also in a dream. Like breathing, this process often occurs involuntarily. The average frequency of swallowing is 5-6 times per minute, however, with concentration of attention or strong emotional arousal, the frequency of swallowing decreases. The process of swallowing is a clear sequence of muscle contractions. This sequence is provided by a region of the medulla oblongata called the swallowing center.

Difficulty swallowing can develop unnoticed by a person. Malnutrition through the mouth, weight loss, a significant increase in the time of swallowing food - all this can be a manifestation of a violation of the swallowing function. Signs of difficulty swallowing may include:

• tilting the head or moving the head from side to side to help move the food bolus;
• the need to drink water with food;

Despite pronounced difficulty in swallowing, the tongue and the muscles that lift the palatine curtain can function normally.

The disorder of the act of swallowing in medicine is called dysphagia.

What diseases cause difficulty in swallowing:

Violation of swallowing can lead to serious consequences:

• exhaustion of the body, weight loss;
• cough during and after swallowing, persistent choking;
• feeling of lack of air during swallowing;
• pain and shortness of breath;
• development of pneumonia;

Depending on the causes of swallowing disorders, there are:

• Mechanical (organic). Such a violation can occur when the size of a piece of food and the lumen of the esophagus do not match.
• functional. This type of difficulty in swallowing occurs when there is a violation of peristalsis, relaxation.

Both mechanical and non-mechanical disturbances can occur for a variety of reasons.

18. Swallowing, its phases, mechanisms and significance

Organic (or mechanical) violation of swallowing is associated with direct external or internal pressure on the esophagus. In such a situation, the patient says that it is difficult for him to swallow food. There can be several reasons for mechanical impact:

1. Blockage of the esophagus by any foreign body or food;
2. Narrowing of the lumen of the esophagus, which can occur due to:

• edema resulting from the inflammatory process (stomatitis, tonsillitis, etc.);
• injuries or scars (burns from taking pills, scars from operations or after inflammation);
• malignant and benign formations;
• stenosis;

3. External pressure may be due to swelling of the thyroid gland, squeezing by blood vessels, etc.

Functional disorders of swallowing include disorders associated with impaired muscle function. Violations can also be divided into 3 groups:

1. Disorders associated with paralysis of the tongue, damage to the brain stem, sensory disturbances, etc.
2. Disorders associated with damage to the smooth muscles of the esophagus. Such violations lead to weakness of contractions and impaired relaxation.
3. Disorders associated with diseases of the muscles of the pharynx and esophagus;

Other causes of difficulty in swallowing include: Parkinson's disease, parkinsonism syndrome, inflammation of the esophageal mucosa, and connective tissue diseases.

“Lump in the throat” syndrome The sensation of a lump in the throat (globus pharyngeus syndrome) is one of the most common complaints at an appointment with an otolaryngologist. Approximately 45% of people experience this sensation during their lifetime. This syndrome began to be studied as one of the manifestations of hysteria, but in the course of the study it became clear that only a part of the cases were due to psychiatric causes.

There are several reasons for the sensation of a lump in the throat:

1. There really is something in the goal and this object interferes with swallowing. The sensation of a lump in the throat in this case can cause swelling of the uvula of the soft palate, tumors or cysts, an enlarged palatine or lingual tonsil. The cases described above are quite rare and are easily excluded during examination at a doctor's appointment.
2. There is a sensation of "lump in the throat", but there are no objects directly in the throat that could interfere with swallowing. These are the most common cases. Most often, this feeling is caused by reflux disease. Reflux is the backflow of stomach contents into the esophagus and down the throat. Muscle spasm in the pharynx, which causes the sensation of "coma", is provoked by gastric contents (the acidic contents of the stomach burn the mucous membrane of the esophagus and throat). Also, the symptom of "coma in the throat" may be accompanied by chronic pharyngitis.
3. Psychological factors. Often, the appearance of the "coma in the throat" syndrome is facilitated by stressful situations, a state of strong excitement or fear.

The globus pharyngeus syndrome has not been fully studied to date, but in most cases it does not pose a threat to human life, and the causes that caused it can be easily eliminated. However, to determine the exact causes and prescribe timely treatment, a full-time examination by a doctor is necessary.

If you have difficulty swallowing or feel a lump in your throat, get advice or make an appointment at the Clinical Brain Institute website.

4. Hydrochloric acid. Mechanism of secretion of hydrochloric acid. Formation of hydrochloric acid in the stomach.
5. The role of hydrochloric acid in digestion. Functions of hydrochloric acid. Enzymes of gastric juice and their role in digestion.
6. Gastric mucus and its significance. Mucus of the stomach. Functions of gastric mucus.
7. Regulation of secretion of gastric juice. Principles of secretion of gastric juice.
8. Phases of gastric secretion. neurohumoral phase. intestinal phase.
9. Gastric secretion during the digestion of various nutrients. secretion to proteins. secretion for carbohydrates. secretion to milk.
10. Contractile activity of the muscles of the stomach. Contraction of the stomach. The work of the stomach.

swallowing- a reflex act by which food is transferred from the oral cavity to the stomach. The act of swallowing comprises three phases: oral (voluntary), pharyngeal (involuntary, fast) and esophageal (involuntary, slow).

food bolus(volume 5-15 cm 3) with coordinated movements of the muscles of the cheeks and tongue moves towards its root (behind the anterior arches of the pharyngeal ring). Thus ends the first phase of swallowing and begins the second. From this point on, the act of swallowing becomes involuntary. Irritation of the mucosal receptors of the soft palate and pharynx by the food bolus is transmitted along the glossopharyngeal nerves to the center of swallowing in the medulla oblongata.

Efferent impulses from it go to the muscles of the oral cavity, pharynx, larynx and esophagus along the fibers of the hypoglossal, trigeminal, glossopharyngeal and vagus nerves. This center provides coordinated contractions of the muscles of the tongue and muscles that lift the soft palate. Due to this, the entrance to the nasal cavity from the side of the pharynx is closed by a soft palate, and the tongue moves the food bolus into the pharynx. At the same time, there is a contraction of the muscles that lift the lower jaw.

This leads to the closing of the teeth and the cessation of chewing, and the contraction of the maxillofacial muscle - to raise the larynx. As a result, the entrance to the larynx is closed by the epiglottis. This prevents food from entering the respiratory tract. At the same time, the upper esophageal sphincter, formed by circular fibers in the upper half of the cervical esophagus, opens, and the food bolus enters the esophagus. This is how the third phase begins.

The upper esophageal sphincter contracts after the food bolus passes into the esophagus, preventing esophago-pharyngeal reflux (i.e., backflow of food into the pharynx). The food then passes through the esophagus and into the stomach. The esophagus is a powerful reflex zone. The receptor apparatus is represented here mainly by mechanoreceptors. Due to irritation of the latter by the food bolus, a reflex contraction of the muscles of the esophagus occurs. At the same time, the circular muscles are consistently contracted (with simultaneous relaxation of the underlying ones).

Variants of swallowing disorders (dysphagia):
a Salivation. b Sensation of a lump in the throat.
a Aspiration into the larynx. d Regurgitation.
d Odynophagia. e Post-swallowing aspiration.

Waves of peristaltic contractions propagate towards the stomach, moving the food bolus. The speed of their propagation is 2-5 cm/s. The contraction of the muscles of the esophagus is associated with the arrival of efferent impulses from the medulla oblongata along the fibers of the recurrent and vagus nerves.

Movement of food through the esophagus due to a number of factors, firstly, the pressure drop between the pharyngeal cavity and the beginning of the esophagus - from 45 mm Hg. Art. in the pharyngeal cavity (at the beginning of swallowing) up to 30 mm Hg. Art. (in the esophagus); secondly, the presence of peristaltic contractions of the muscles of the esophagus, thirdly, the tone of the muscles of the esophagus, which in the thoracic region is almost three times lower than in the cervical region, and, fourthly, the gravity of the food bolus. Speed ​​of food passing through the esophagus depends on the consistency of food: dense passes in 3-9 s, liquid - in 1-2 s.

swallowing center through the reticular formation it is connected with other centers of the medulla oblongata and spinal cord. His arousal at the time of swallowing causes inhibition of the activity of the respiratory center and a decrease in the tone of the vagus nerve. The latter causes breath holding and increased heart rate. Holding your breath prevents food from entering your airways.

In the absence of swallowing contractions the entrance from the esophagus to the stomach is closed, since the muscles of the cardial part of the stomach are in a state of tonic contraction. When the peristaltic wave and lump food reach the final part of the esophagus, tone muscles of the cardia of the stomach reflexively decreases, and a lump of food enters the stomach. When the stomach is filled with food, muscle tone cardia of the stomach increases and prevents the return of gastric contents from the stomach to the esophagus ( gastroesophageal reflux).

The mechanism of swallowing is a complex reflex act by which food passes from the oral cavity to the esophagus and stomach. Swallowing is a chain of successive interrelated stages that can be divided into 3 phases:

• oral (arbitrary);
• pharyngeal (involuntary, fast);
• esophageal (involuntary, slow).

The oral phase of swallowing begins from the moment when the food bolus (volume 5-15 cm3) moves towards the root of the tongue, behind the anterior arches of the pharyngeal ring, with coordinated movements of the cheeks and tongue, and from that moment the second phase begins - the pharyngeal phase of swallowing, which now becomes involuntary.

The pharynx is a cone-shaped cavity located behind the nasal, oral cavity and larynx. It is divided into 3 parts: nasal, oral and laryngeal. The nasal part performs a respiratory function, its walls are motionless and it does not collapse, its mucous membrane is covered with ciliated epithelium of the respiratory type. The oral part of the pharynx is mixed in its function, since the digestive and respiratory tracts cross in it.

Irritation of the receptors of the mucous membrane of the soft palate and pharynx by the food lump stimulates the 2nd phase of swallowing. Afferent impulses are transmitted along the glossopharyngeal nerve to the center of swallowing in the medulla oblongata. From it, efferent impulses go to the muscles of the oral cavity, pharynx, larynx and esophagus, along the fibers of the hypoglossal, trigeminal, glossopharyngeal, vagus nerves and provide the occurrence of coordinated contractions of the muscles of the tongue and muscles that raise the palatine curtain (soft palate).

Due to the contraction of these muscles, the entrance to the nasal cavity is closed by a soft palate, the entrance to the pharynx opens, where the tongue pushes the food bolus. At the same time, the hyoid bone is displaced, the larynx rises and the epiglottis does not close the entrance to the larynx, which prevents food from entering the respiratory tract. At the same time, the upper sphincter of the esophagus opens, where the food bolus enters and the esophageal phase of the movement of the food bolus begins - this is the passage of food through the esophagus and its transition to the stomach.

The esophagus (esophagus) is a tube of relatively small diameter with a well-developed muscular layer that connects the pharynx and stomach and ensures the movement of food into the stomach. The length of the esophagus from the front teeth through the pharynx is 40-42 cm. If 3.5 cm is added to this value, then this distance will correspond to the length of the probe in order to receive gastric juice for research.

The movement of the food bolus through the esophagus is due to:

• pressure drop between the pharyngeal cavity and the beginning of the esophagus (at the beginning of swallowing in the pharyngeal cavity 45 mm Hg, in the esophagus - up to 30 mm Hg);
• peristaltic contractions of the muscles of the esophagus;
• muscle tone of the esophagus, which in the thoracic region is almost 3 times lower than in the cervical;
• gravity of the food bolus.