It is believed that a person distinguishes either four or five elementary tastes: salty, sour, sweet, bitter and one more, for which there is no Russian name. It is called "umami" and is attributed to the taste of MSG. However, it is sometimes called “sweet,” and food manufacturers believe that MSG simply enhances the sensation of other flavors. If you believe books about food, then it turns out there are not five tastes, but many thousands, but culinary specialists do not mean elementary tastes, but combined ones. Recently, scientists have suspected that there are more than five of them.

It turned out that the taste buds of rats react differently to different bitter substances. The bitter pathogen causes an increase in calcium concentration in the receptor cell, which prompts the cell to secrete a transmitter (a chemical transmitter of impulses between nerve cells). To study this process, biologists A. Caicedo and S. Roper from the University of Miami (USA) introduced a fluorescent label into the taste cells of rat tongues that responds to an increase in calcium levels. They then exposed the cells to various bitter compounds. It turned out that 66 percent of bitter-sensitive cells responded to only one compound, 27 percent to two, and 7 percent to more than two compounds. This means that the taste buds that respond to different bitter substances are different, but we only have one name for “bitter.” Or it is possible that rats are simply better at understanding the bitter side of life than humans.

What does taste consist of?

Different substances can have a pure or mixed taste. The taste of all purely bitter substances is perceived by humans in exactly the same way. Thus, solutions of opium, strychnine, morphine, quinine may differ from one another in the intensity of the feeling of bitterness they cause, but not in its quality. If we equalize the intensity of the sensation by taking the listed solutions in different concentrations, then they become indistinguishable. The same applies to sour tastes. Solutions of hydrochloric, nitric, sulfuric, phosphoric, formic, oxalic, tartaric, citric and malic acids, taken in appropriate dilutions, taste indistinguishable. In the study of sweet substances, it was also found that there are not several types of sweets. Certain substances may have a more or less pronounced sweet taste, but if this taste is purely sweet, then their solutions cannot be distinguished from one another. Glucose, fructose, lactose, and sucrose have a purely sweet taste. Regarding the salty taste, it has been proven that only one substance has it in its purely expressed form - table salt. All other salty substances have a bitter or sour taste.

How do flavors mix? Sour and sweet substances can cause the sweet and sour sensation found in many apple varieties or fruit drinks. An example of a sour-salty sensation is the taste of cucumber pickle. It’s difficult for bitter and sweet to merge, but bitter cocoa mixed with sugar creates a unique fused sensation characteristic of chocolate. But the fusion of bitter with salty and especially bitter with sour does not occur at all. Mixtures of bitter and salty, bitter and sour substances are extremely unpleasant to the taste.

How does a taste analyzer work?

It would be possible to find out what elementary taste is by determining how many types of analyzer cells are involved in perception. But, unlike vision, this has not yet been done. Note that, hypothetically, you can have one type of cell, or even just one single cell, but by measuring the signal coming from it with high accuracy, you can get at least five or fifty thousand values. A good digital voltmeter or frequency meter has even greater resolution. Of course, it is advisable for both humans and animals to be able to distinguish between several different tastes - say, by the number of frequently occurring harmful substances and products that require different compositions gastric juice. How convenient it would be to have many types of sensitive cells tuned to different substances or types of substances, for example, an indicator of rotten meat, an indicator of wolfberry, indicators of meat and plant foods, an indicator of creme brulee ice cream.

The cells that perceive taste stimuli are collected into taste buds (or buds) about 70 micrometers in size, which are located on the taste buds. In humans, these structures are located on the tongue. The number of taste cells in a taste bud ranges from 30 to 80 (although some sources call both smaller and larger numbers). Large papillae at the base of the tongue contain up to 500 taste buds each, small papillae on the front and side surfaces of the tongue contain several bulbs, and in total a person has several thousand taste buds. There are four types of papillae, differing in location and shape: mushroom-shaped on the tip of the tongue, leaf-shaped on the lateral surface, grooved on the front of the tongue and filiform, containing receptors that are not sensitive to taste, but only to temperature and mechanical stress. The influence of temperature and mechanical influence on the sensation of taste is not realized in the brain (as the influence of smell on the sensation of taste), but at a lower level, that is, it is already provided for by the structure of the receptor mechanism. The perception of temperature and mechanical action is thought to be important in producing the sensation of acrid, astringent, and astringent flavors.

The glands between the papillae secrete a fluid that washes the taste buds. The outer parts of the taste receptor cells form microvilli 2 micrometers long and 0.1–0.2 micrometers in diameter, extending into the common chamber of the bulb, which communicates with the external environment through a pore on the surface of the papilla. Stimulating molecules reach the taste cells by penetrating through this pore. Single taste buds (not associated with papillae) are present in aquatic vertebrates on the surface of the head, on the gills, fins, and in the pharynx; in terrestrial vertebrates, on the back surface of the tongue, cheeks, and upper part of the pharynx.

Taste cells are replaced very quickly, their lifespan is only 10 days, after which new receptors are formed from the basal cells. New taste sensory cells communicate with sensory nerve fibers - the specificity of the fibers does not change. As an engineer would say, parts are replaced, but the circuit remains the same. The mechanism that ensures this interaction between the receptor and the fiber is still unknown.

Taste receptor cells do not have axons (long cell processes that conduct nerve impulses). Information is transmitted to the endings of sensitive fibers using transmitters - “intermediate substances”. Processing of the taste signal (as well as the visual signal, by the way) is organized hierarchically. A single nerve fiber branches and receives signals from the receptor cells of different taste buds, so each fiber has its own “taste profile.” Some fibers are especially strongly stimulated by the action of bitter, others - by the action of salty, sweet or sour. Further processing occurs in the brain. It is possible that different echelons of signal processing - both gustatory and visual - are a legacy of evolution (see epigraph): evolution does not “reverse”, and the method of signal processing, implemented at a stage when there was no brain yet, is preserved in the genus Homo , only this method is complemented by others. Maybe that’s why people are so complex in general? In particular, it is still unknown at what level, that is, where and how, five elementary signals form all those thousands of tastes that a trained person distinguishes. This can happen in at least three different places: directly in the cells, in the nerve network that delivers the signal to the brain, and finally in the brain.

The visual signal, by the way, is also processed in more than one place - in the frog’s eye there are specialized groups of cells that respond to certain elements of the image. And the retina consists of several layers of cells, that is, part of the signal processing occurs in the eye, and partly in the brain. Borrowing this idea from nature allowed the American cyberneticist F. Rosenblatt to create in the middle of the last century the “perceptron” - a signal processing device that is now widely used by humans in pattern recognition. The reason for the effectiveness of the perceptron is still not understood, just as the reason for the effectiveness of its prototype, that is, the eye, is not understood. To peek and to understand are completely different things; Many of our readers - schoolchildren and students - know this well.

Taste at the cellular level

It is still not clear whether the specific receptor is a taste bud or a taste cell. If the first hypothesis is correct, then we can assume that there are papillae containing bulbs of only one type, two or three types and finally, all kinds. Moreover, the predominant number of bulbs excited by each type of stimulus are located in the papillae located in different areas of the surface of the tongue, due to which these areas are unequally susceptible to different influences, but still, to some extent, have sensitivity to each of them. And some authors believe that the receptor sites of taste cells respond to taste stimuli of various types, and each taste cell can have receptor sites of several types.

How exactly the cell perceives the signal from the substance is also not yet known for certain. It is believed that the receptors for salty and sour are ion channels (and the sour taste is created simply by hydrogen ions), and other sensations are caused by the fact that the taste substances do not act on the cells themselves, but first enter into a chemical reaction with some protein, but the result of the reaction affects the cells. Indeed, in taste buds there are fractions of protein macromolecules that react with sweet and bitter substances. In this case, insensitivity to sweet and bitter must be associated with disturbances in the activity of certain genes. In support of this hypothesis, genetic differences were found between people with and without sweet tastes. There is information in the literature that the interaction of substances with the cell has several stages, that the last of them are enzymatic in nature, that in this case, the catalytic breakdown of ATP (adenosine triphosphoric acid) occurs in the taste cell and the energy necessary for the emergence of receptor potential is released. It is possible that there is a second receptor system - in some animals bare nerve endings were found distributed between the papillae. They react to high concentrations and inhibit the activity of other receptors - in radio engineering terms, they carry out negative feedback that expands the dynamic range of the analyzer, that is, the ability to perceive both weak and strong signals.

Oddly enough, the connection between chemical properties substances and their taste are rather weak, although it is known that some chemically similar substances have a similar taste. For example, a sweet taste is characteristic of sugar, lead salts and sugar substitutes - substances that, from a chemist's point of view, have very little in common. But the taste analyzer thinks differently. Moreover, the perceived taste of a substance depends on the concentration of the latter - for example, table salt in small concentrations seems sweet. Therefore, reports that appear from time to time about the creation of a device that distinguishes taste can be considered some exaggeration. It is possible to make a chemical analyzer for any substance or group of substances, but until we can understand exactly how a natural analyzer works, we will not be able to claim that the device we have created is capable of correctly identifying the taste of a substance that has not previously been presented to it.

Something about the shape of the glass

In 1901, the journal Philosophische Studien published for the first time a map of the location of taste buds on the tongue: the tip is sensitive to sweetness, the back to bitterness, acidity is most felt by the lateral points of the tongue, and saltiness is perceived approximately equally at all points. Therefore, for the sensation of taste, it is important which part of the tongue the substance lands on. Usually we perceive food with the whole tongue, but winemakers claim that the taste of wine depends on the shape of the glass, since the shape and volume of the bowl of the glass, the diameter of the edge and its processing (the edge can be cut at a right angle or have a rounded rim), the thickness of the walls are factors , which determine the point of primary contact of the drink with taste buds, and therefore affect the perception of taste and smell. For example, the Austrian Georg Riedel, who designs and produces glassware, argues that wines from different grape varieties require glasses of different shapes. For example, he designed a special Riesling glass with a thin, tapered rim to allow the wine to flow into the mouth without touching the sides of the tongue, which react to high acidity. The increased acid content in Riesling is due to the fact that it is made from grapes grown in cold northern climates and without lactic acid fermentation. A chardonnay glass, on the other hand, should be wider to bring out the acid rather than dilute its flavor, since chardonnay wines come from warmer climates and undergo lactic acid fermentation.

After the substance has hit the tongue, first there is a sensation of touch (that is, a tactile feeling), and only then - taste sensations in the following order: at the tip of the tongue, salty taste appears first, followed by sweet, sour and lastly bitter; based on the tongue - first of all bitter, then salty and last of all sweet. These differences can also somehow affect the overall sensation of taste.

Why do we need taste and how to train it

The signal from taste buds is used by the body in two ways. Firstly, unconsciously - for example, to control gastric secretion, both its quantity and composition, that is, the taste of food is not only a signal that it is time to digest food, but also an order for the composition of gastric juice. Secondly, taste is used consciously - to enjoy food.

Some argue that the sense of taste can be trained. And if you concentrate your attention on the tip of your tongue, salivation will begin. Take, they say, a piece of sugar and place it in front of you. Look at it, close your eyes, imagine this piece and, continuing to keep your attention on the tip of your tongue, try to evoke the taste of sugar. Typically, taste sensations appear within 20–30 seconds, and they intensify from exercise to exercise. If you are having trouble with it, try first putting a grain of sugar on the tip of your tongue, then intensifying the corresponding taste sensations. Train for 15-20 minutes 3-4 times a day for 7-10 days. After you learn to evoke the taste of sugar, cheese and strawberries, you need to master the transitions from one taste to another, for example, learn to replace the taste of cheese with the taste of strawberries. Having mastered this method, you will be able to arbitrarily, easily and simply change your taste sensations. I tried it, but apparently I fell into that 5-7 percent of people who are unable to “imagine” the taste at will.

Not on your own

Taste sensations are associated with olfactory, tactile and thermal sensations. It is known how taste sensations are weakened when the sense of smell is excluded, for example, with a runny nose (by the way, also when smoking). Those aspects of taste sensations that are defined by words such as astringent, mealy, pungent, burning, tart, sticky are determined by a tactile reaction. The taste of freshness, such as mint or menthol, may be due to an admixture of thermal sensations (local cooling due to rapid evaporation). It is sometimes argued that taste sensations can be caused by mechanical action, simply put - touch or pressure of a stream of air, as well as changes in temperature. But in the first case, everything is complicated by chemical interaction, in the second - by heat transfer itself, cooling due to evaporation and, possibly, changes in surface humidity. The sensation that occurs when you touch the tongue of the battery contacts (do not try to use a voltage greater than 4.5 volts) is explained by electrolysis and the formation of ions. Researchers from Yale University (USA) have shown that the sensation of sour or salty occurs when the edges of the tongue are cooled to 20°C; When the edges or tip of the tongue are warmed to 35°C, a sweet taste is felt.

According to some reports, bitter substances directly introduced into the blood also stimulate the taste nerves. For example, after an injection of a bitter substance in a dog, the same jaw movements and grimace of disgust appear as when the substance is applied to the tongue. It happens that people complain of bitterness in the mouth some time after taking quinine in wafers, when quinine has already entered the blood. However, in all these cases it is possible that the bitter substance gets directly onto the tongue.

Cooling and heating reduce sensitivity to taste: a tongue cooled with ice for a minute ceases to taste sugar; when the surface of the tongue is heated to 50°C, sensitivity also decreases. The area of ​​greatest sensitivity is from 20 to 38°C.

The taste for a known substance may be enhanced by contrast with the taste of another, pre-active substance. Thus, the taste of wine is enhanced by the preliminary consumption of cheese and, on the contrary, is dulled and spoiled after all the sweets. If you first chew the root of the iris pseudacorus, the coffee and milk will taste sour. Such an influence of some tastes on others may depend both on purely chemical processes on the tongue, and on the mixing in our consciousness of the trace left by a previous taste sensation with a new taste stimulation. Tastes are easy to compensate for one another and make them pleasant, for example, an overly sour taste - sweet, but at the same time there is no direct mixing of sensations, giving something in between, since the tastes of sweet and sour remain the same strength when mixed, and only our attitude towards him from the point of view of pleasantness. Compensation of tastes, not accompanied by compensation of the chemical properties of flavoring substances, occurs in central authorities our feelings. The struggle of taste sensations is easiest to observe if you put a sour substance on one half of the tongue and a bitter substance on the other; at the same time, a feeling of either sour or bitter arises in the consciousness, and a person can arbitrarily dwell on one or the other, but the mixing of both tastes into something in between does not occur.

The entire structure of gastronomy is based on the phenomena of contrast of tastes, their compensation and traces, which has the physiological value that a good, pleasant taste of food promotes its digestion, enhancing the secretion of digestive juices and causing a mood so favorable for the normal course of all bodily processes in the body.

The connection between taste and olfactory sensations is obvious. You can reduce the influence of olfactory sensations on taste by pinching your nose tightly and refraining from breathing movements during tasting. At the same time, the “taste” of many substances changes completely: for example, onions become sweet and the taste is difficult to distinguish from a sweet apple. Fruits, wines, jams - they all have a sweet, sour or sweet-sour taste. Meanwhile, the variety of sensations caused by them is enormous. This is determined not by their taste, but by their olfactory properties.

Finally, great importance has a chemical effect of saliva on substances in the mouth. You can easily verify this if you take a piece of unleavened food into your mouth. white bread. Starch, which is insoluble in water and is the main carbohydrate contained in such bread, has no taste. As soon as you chew the bread, that is, bring it into contact with saliva, it acquires a distinct sweetish taste, a sign that part of the starch has been broken down by salivary enzymes into glucose.

This complex mechanism sometimes breaks down. The complete loss of all taste sensations is called ageusia, weakening of sensations is called hypogeusia, and other changes in the perception of taste sensations are called parageusia. A change in taste sensations can occur as a result of damage to the mucous membrane of the tongue due to inflammation and burns - thermal and chemical. Loss of taste sensitivity is also observed when the pathways of the taste analyzer are damaged: loss of taste in the anterior two-thirds of one half of the tongue is associated with damage to the lingual or facial nerve, in the area of ​​the posterior third of the tongue - when damaged glossopharyngeal nerve. If certain brain structures are damaged, loss of taste sensitivity may occur in the entire half of the tongue. In some cases, changes in taste are caused by diseases of internal organs or metabolic disorders: a feeling of bitterness is noted in diseases of the gallbladder, a feeling of acidity in diseases of the stomach, a feeling of sweetness in the mouth in severe forms of diabetes. In some diseases, the perception of some tastes remains normal, while others are lost or distorted. Most often this is observed in mental patients, and the origin of these disorders is associated with the pathology of the deep sections temporal lobe brain Such patients often enjoy eating unpleasant or unhealthy substances.

But a healthy person usually does not do this. And thanks for this we must say to our natural taste analyzer.

The most simple joy in a person’s life is delicious food. It would seem that you go to the kitchen, open the refrigerator, spend a certain amount of time at the stove - and voila! – a fragrant dish is already on the table, and endorphins are in your head. However, from the point of view of science, the entire meal from start to finish is a complex multifaceted process. And how difficult it sometimes is for us to explain our eating habits!

The study of taste buds is carried out by a young and still developing science - the physiology of taste. Let's look at some basic tenets of the teaching that will help us better understand our taste preferences and momentary weaknesses.

Human taste buds

Taste is one of the five senses of perception, which are very important for human life. The main role of taste is to select and evaluate food and drink. Other senses, especially smell, help him a lot in this.

The taste mechanism is driven by chemicals found in food and drink. Chemical particles, collecting in the mouth, turn into nerve impulses that are transmitted along the nerves to the brain, where they are deciphered. The surface of the human tongue is covered with taste buds, of which an adult has from 5 to 10 thousand. With age, their number decreases, which can cause certain problems with distinguishing tastes. The papillae, in turn, contain taste buds, which have a specific set of receptors, thanks to which we experience the whole gamut of taste diversity.

They respond to only 4 basic tastes - sweet, bitter, salty and sour. However, today a fifth element is often identified – umami. The newcomer’s homeland is Japan, and translated from the local language it means “appetizing taste.” In fact, umami is the taste of protein substances. Monosodium glutamate and other amino acids create the umami sensation. Umami is an important component of the flavor of Roquefort and Parmesan cheeses. soy sauce, as well as other unfermented products - walnut, tomatoes, broccoli, mushrooms, thermally processed meat.

The socio-economic conditions in which a person lives, as well as his work, are considered a completely natural explanation for the choice of food. digestive system. Meanwhile, scientists are increasingly inclined to believe that taste preferences are determined by genes and heredity. This question was first raised in 1931 during research involving the synthesis of the odoriferous molecule phenylthiocarbamide (PTC). Two scientists perceived the substance differently: for one it was bitter and very odorous, while the other found it completely neutral and tasteless. Later, the head of the research group, Arthur Fox, tested the FTC on members of his family, who also did not feel it.

Thus, in Lately Scientists tend to think that some people perceive the same taste differently and that some are programmed to gain weight from French fries, while others can eat them without harm to their figure - this is a matter of heredity. In support of this statement, scientists from Duke University in the USA, together with colleagues from Norway, proved that people have a different composition of genes responsible for odors. The study focused on the relationship of the OR7D4 RT gene to a steroid called androstenone, which is found in high quantities in pork. Thus, people with identical copies of this gene are disgusted by the smell of this steroid, and owners of two different copies of the genes (OR7D4 RT and OR7D4 WM), on the contrary, do not feel any hostility.

Interesting facts about tastes

• Taste buds on the human tongue live on average 7-10 days, then they die and new ones appear. So don't be surprised if the same taste tastes a little different from time to time.

• About 15-25% of people in the world can safely be called “supertasters,” that is, they have an extremely sensitive taste, since there are more papillae on the tongue, and therefore more taste buds.

• The taste buds on the human tongue for sweet and bitter tastes were discovered just 10 years ago.

• All pure tastes are felt absolutely equally by a person. This means that we cannot talk about several types of sweet taste. To taste, there is just one sweet taste, which, however, can vary in intensity: be brighter, richer or faded. The situation is similar with other tastes.

• Taste buds are most sensitive between 20-38 degrees. If you cool your tongue, for example, with ice, then you may no longer feel the taste of sweet food or it may change significantly.

• Good taste is formed in the womb. Thus, scientists have found that the taste of some foods is transmitted not only through mother’s milk, but also through the amniotic fluid while the baby is in the mother’s belly.

• American scientists conducted a study that established the dependence of taste preferences on a person’s age and gender. So, girls mostly prefer sweets, fruits, and vegetables. Boys, on the contrary, love fish, meat, poultry and, for the most part, are indifferent to chocolate.

• During air travel due to high level noise, a person’s taste sensitivity to salty and sweet things decreases.

• The taste of the cookies is 11 times better when washed down with milk drinks. But coffee, on the contrary, “kills” all other sensations. Therefore, if you want to to the fullest To enjoy your dessert, it is better to choose the right drinks and drink coffee separately from other food.

Sweet

Sweet taste is perhaps the most pleasant for the majority of the world's population. It is not for nothing that the expression “sweet life” appeared, and not any other. At the same time, not only flour and confectionery products are sweet, but also products of natural origin. Along with this, they are also useful. Most sweet foods contain large amounts of glucose. And as you know, glucose is the main metabolic fuel for the human body. That is why taste buds easily recognize sweet tastes, and at the same time produce happiness hormones - serotonin and endorphin.Please note that these hormones are addictive. This is the explanation for the fact that we prefer to eat depression and stress with something sweet.

It's no secret that excessive consumption of sweets has an adverse effect on your figure and skin condition. However, you shouldn’t give up desserts completely. Do not eat treats on an empty stomach and, whenever possible, try to replace them with dried fruits, honey, and nuts.

Sour

Most acidic foods contain ascorbic acid. And if you suddenly have a craving for something sour, know that this may indicate a lack of vitamin C in your body. Such taste changes can even serve as a signal of an oncoming cold. The main thing is not to overdo it: you should not actively supply your body with this useful substance, everything is good in moderation. Excess acid negatively affects the functioning of the digestive system and the condition of tooth enamel.

If a lot of acid is involved in the metabolism, the body will try to get rid of its excess. This happens in different ways. For example, through the lungs by exhaling carbon dioxide or through the skin by sweating. But when all possibilities are exhausted, acids accumulate in the connective tissue, which impairs the functioning of the digestive system and provokes the accumulation of toxins in the body.

The daily requirement of vitamin C for adult men and women is 70-100 milligrams. It is especially abundant in sour berries (gooseberries, currants, cranberries), citrus fruits and kiwis, and fresh vegetables (especially bell peppers).

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Taste disturbance

In his daily life, a person quite often encounters such an incident as a taste disorder (hypogeusia).

It can be short-term (for example, you put too hot food in your mouth and you stop feeling taste for some time) or long-term - it can be a consequence of deeper disorders in the human body, or one of the symptoms of a serious illness.

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ICD-10 code

R43 Impaired sense of smell and taste

Causes of taste disturbance

This diagnosis is made to the patient when the patient is unable to ascertain the taste of any product:

• If the damage has affected the taste buds. Doctors refer to this pathology as transport losses.
• If the pathology damages the receptor cells. Doctors classify it as sensory impairment.
• Damage to taste caused by pathology of the afferent nerve or malfunction of the central taste analyzer. This pathology can be attributed to neural changes.

What are the causes of taste disturbance:

• Facial nerve, complete or partial paralysis. This pathology is characterized by loss of taste perception at the tip of the tongue and paralysis of the facial muscles. The affected part of the face looks like a frozen, distorted mask. Paralysis leads to increased salivation and lacrimation, and the process of blinking is difficult.
• Craniocerebral lesion. As a result of the injury, the integrity of the cranial nerve was apparently damaged. In this case, the patient finds it difficult to differentiate complex taste compositions, while the patient normally distinguishes basic tastes (sweet, sour, salty and bitter). Other symptoms of this pathology include bleeding from the nasal cavity, nausea and dizziness, headaches and deterioration of visual perception.
• Colds. Quite often, this common disease is accompanied by a blockage of the sense of smell. Swelling of the nasopharyngeal area, fever, decreased vitality, chills and aches, and cough are also manifested.
• Cancerous tumors in oral cavity. Approximately half of the cases of tumor involvement in the oral cavity occur in the posterolateral region of the tongue, which most often leads to necrosis of the taste buds. And as a result - a violation of taste. With this disease, speech is also impaired, the process of chewing food becomes problematic, and bad smell which spreads from the mouth.
• Geographical language. Doctors coined this term for inflammation of the papillae of the tongue, which manifests itself as hyperemic spots of various shapes covering the tongue. The spotted pattern is somewhat reminiscent of a geographical map.
• Candidiasis or thrush. This disease is manifested by a fungal infection of the oral cavity and is expressed by the appearance of creamy and milky-colored spots on the palate and tongue. The patient feels a burning sensation and painful sensations, there is a violation of taste perception.
• Sjögren's syndrome. This disease has genetic roots. Symptoms of its manifestation are disturbances in the functioning of the secretory glands, such as sweat, salivary, lacrimal. Blocking salivation leads to dryness of the oral mucosa, impaired taste perception, and periodic infection of the cavity. Similar dryness appears on the cornea of ​​the eye. The symptoms of this disease also include nose bleed, an increase in the size of the salivary and lacrimal glands, dry cough, swelling of the throat and others.
• Spicy viral hepatitis. The symptom that precedes the manifestation of other signs of this disease is jaundice. In this case, the olfactory perception becomes distorted, nausea and vomiting appear, appetite disappears, general weakness increases, muscle pain, headaches, joint pain, and others intensify.
• Consequences radiation therapy. Having received in the treatment of this terrible disease dose of radiation to the neck and head, the patient develops a bunch of pathologies and complications. Some of them are taste disturbances and dry mouth.
• Thalamic syndrome. This pathology carries with it changes in the normal functioning of the thalamus, which quite often leads to such a disorder as a curvature of taste perception. Primary symptom developing disease and the signal bell becomes a superficial and quite deep loss of skin sensitivity with the manifestation of partial paralysis and significant loss of vision. In the future, sensitivity can be restored and develop into hypersensitivity, for example, to pain.
• Zinc deficiency. Laboratory studies often show a lack of this chemical element in the body of patients with taste disorders, which indicates its significant role in preventing hypogeusia. Zinc deficiency leads to a malfunction in the sense of smell. The patient may begin to perceive unpleasant, repulsive odors as a wonderful aroma. Other symptoms of element deficiency include hair loss, increased brittleness of nails, and enlarged spleen and liver.
• Lack of vitamin B12. This seemingly insignificant deviation in the mineral content of the body can provoke not only hypogeusia (impaired taste), but also disruptions in the sense of smell, as well as weight loss, up to anorexia, swelling of the tongue, impaired coordination of movement, shortness of breath and others.
• Medications. There are many medications that can, in the process of taking them, influence changes in taste preferences. Here are some of them: penicillin, ampicillin, captopril, clarithromycin, tetracycline (antibiotics), phenytoin, carbamazepine (anticonvulsants), clomipramine, amitriptyline, nortriptyline (antidepressants), loratadine, horpheniramine, pseudoephedrine (antiallergic drugs and medications that improve nasal airway). ), captopril, diacarb, nitroglycerin, nifedipine (antihypertensive (pressure), cardiotropic (heart)) and many others. There are hundreds of them, and before you start taking this or that drug, you should re-read the instructions for use and side effects.
• Ear plastic surgery. Hypogeusia may develop as a result of unprofessional performance of this operation or in connection with physiological characteristics body.
• Long-term smoking (especially pipe smoking). Nicotine can lead to partial atrophy of taste buds or distortion of their functioning.
• Injuries to the mouth, nose or head. Any injury is fraught with consequences. One of these consequences may be a violation of taste and smell.
• If hypogeusia is suspected in a small child, do not rush to conclusions. In fact, it may turn out that the baby simply does not want to eat or does not want to eat this particular product.

Symptoms of taste disturbance

Before moving on to a more detailed introduction to this disease, let's define the terminology. Based on clinical studies and based on patient complaints, doctors classify symptoms of taste disturbance into certain categories:

• General ageusia is a problem in recognizing simple basic tastes (sweet, bitter, salty, sour tastes).
• Selective ageusia is difficulty in recognizing certain flavors.
• Specific ageusia is a decreased sensitivity of taste to certain substances.
• General hypogeusia is a violation of taste sensitivity, which manifests itself in the case of all substances.
• Selective hypogeusia is a taste disorder that affects certain substances.
• Dysgeusia - perverted manifestations in taste preferences. This is either an incorrect taste sensation of a specific substance (sour and bitter tastes are often confused). Or a somatically imposed perception of tastes against the background of absent taste stimuli. Dysgeusia can develop both on a semantic basis and in pathology at the physiological or pathophysiological level.

Forms

Impaired sense of smell and taste

There are quite rare cases when, with a particular disease, a patient is diagnosed with either only a taste disorder, or, individually, a disorder of smell. This is rather an exception to the rule. Much more often, in most diagnosed cases, disorders of smell and taste go hand in hand. Therefore, if a patient complains of loss of taste, the attending physician must also examine his sense of smell.

Such an interrelated disorder rarely leads to disability and is not life-threatening, but a violation of taste and smell can greatly reduce the quality of social life. Often these changes, especially in older people, can lead to apathy, loss of appetite and, ultimately, exhaustion. Loss of smell can also lead to dangerous situations. For example, the patient simply will not feel the odorant (flavored fragrance) that is specially mixed into natural gas. As a result, it does not recognize a gas leak, which can lead to tragedy.

Therefore, before declaring the symptoms to be harmless, the attending physician must exclude underlying, systemic diseases. Since hyperosmia (increased sensitivity to odors) can manifest itself as one of the symptoms of diseases of a neurotic nature, and dysosmia (perverted sense of smell) - with the infectious genesis of the disease.

Adequate perception of taste in a person occurs when all groups of receptors work in the recognition process: both facial and glossopharyngeal, as well as receptors vagus nerve. If at least one of these groups, due to reasons, falls out of the examination, the person receives a taste disorder.

Taste receptors are distributed over the surface of the oral cavity: the palate, tongue, pharynx and pharynx. When irritated, they send a signal to the brain and the brain cells recognize this signal as taste. Each group of receptors is “responsible” for one of the basic tastes (salty, bitter, sweet, sour) and only when working together in a complex manner are they able to recognize the nuances and subtleties of taste shades.

Diagnosis of taste disorders

Before proceeding with diagnosis, it is necessary to clearly identify the case when the patient not only finds it difficult to determine the taste of the product, but also suffers from a pathology of smell.

First of all, the specialist tests taste sensitivity throughout the entire oral cavity, determining its threshold for manifestation. The patient is asked to determine the taste one by one. citric acid(sour), table salt(salty), sugar (sweet) and quinine hydrochloride (bitter). The test results form the clinical picture and extent of the lesion.

The qualitative threshold of sensations in certain language areas is checked by applying a few drops of the solution to certain areas of the oral cavity. The patient swallows and shares his feelings, but the characteristics are given differentiated, for each area separately.

Today, research methods such as electrometric ones have appeared, but they do not paint a sufficiently clear, reliable picture of perception, so the diagnosis of taste disorders is carried out the old fashioned way, with clinical taste tests.

As in the case of pathology of smell, in case of taste disturbance, at the moment, there are no precise methods that can categorically differentiate the causes of a sensory, transport or neural nature. In order for the doctor to be able to more specifically determine the cause of the neurological disorder, it is necessary to localize the location of the lesion as accurately as possible. The patient's medical history also provides important information for the attending physician. It is necessary to exclude genetically transmitted endocrine diseases.

It is also necessary to investigate the side effects of drugs if the patient is being treated for another disease. In this case, the attending doctor will either prescribe another drug with the same effect, or change the dosage of the first one.

Computed tomography is also performed. It will provide a clinical picture of the condition of the sinuses and medulla. It is necessary to exclude or confirm the presence of systemic diseases. Diagnostics of the oral cavity will help determine possible local causes (diseases) that can lead to taste disturbances: malfunction of the salivary glands, otitis media, prosthetic teeth in the upper jaw, and others.

The doctor is also interested in whether the patient has traumatic brain injuries, laser irradiation of the head and neck area, or diseases associated with inflammatory processes of the central nervous system and cranial nerves.

The attending physician also establishes the chronology of the occurrence of the disease, injury or surgical intervention with the appearance of taste disturbance. It is necessary to understand whether the patient has contact with toxic chemicals?

For women, important information is the onset of menopause or recent pregnancy.

There are also laboratory research. They are able (detailed blood test) to give an answer whether there are foci of infectious lesions or manifestations of an allergic nature in the patient’s body, anemia, blood sugar levels ( diabetes). Carrying out special tests will allow you to recognize liver or kidney pathologies. And so on.

If there are any suspicions, the attending physician refers his patient for consultation with a specialized specialist: otolaryngologist, dentist, endocrinologist, neurologist, and so on. And in the presence of a traumatic brain injury, the patient undergoes an X-ray, as well as a CT or MRI of the head, which will help identify intracranial changes or disorders of the cranial nerves.

If obvious reasons taste disturbances cannot be found; after two to four weeks a re-diagnosis is carried out.

Treatment of taste disorders

First of all, the treatment of taste disturbance is the elimination of the cause of its occurrence, that is, it is a set of measures that lead to the relief or complete eradication of the disease that led to this pathology

Treatment can begin not after the doctor has identified a taste disorder, but after the source and cause of this pathology have been fully established.

If the cause of taste disturbances is a drug that the patient takes during treatment, then the attending physician, after the patient’s complaints, will either change the drug to another of the same group, or change the dosage of the first one if it is impossible to replace it.

In any case, if the problem exists and has not yet been solved, or the composition of the secretions has changed, artificial saliva is used.

• "Hyposalix"

This medical drug used to moisturize the oral cavity, which will completely or partially restore the resulting taste disturbance.

The solution is sprayed into the mouth while the patient is sitting or standing. The medical spray is alternately directed at inner side first one, then the other cheek. Spraying is carried out with a single press. The number of daily repetitions is six to eight times. It is not limited to a time frame, but is sprayed as needed - if the patient begins to feel dry mouth. This drug is non-toxic, it can be safely used by pregnant women and small children, there are no contraindications during lactation.

If the source of the problem is bacterial and fungal diseases– the treatment protocol for such a patient will consist of drugs that can inhibit harmful pathogenic flora.

• Erythromycin

Daily dose of the drug:

• for newborns under three months of age – 20-40 mg;
• for children from four months to 18 years – 30-50 mg per kilogram of the child’s weight (in two to four doses);
• for adults and adolescents who have crossed the threshold at 14 years - 250 - 500 mg (one-time dose), repeated dose no earlier than 6 hours later, the daily dosage can be increased to 1-2 g, and in severe forms of the disease up to 4 g.

When taking this drug, some side effects may occur: nausea, vomiting, dysbacteriosis and diarrhea, dysfunction of the liver and pancreas, and others. This drug is contraindicated during lactation, as it penetrates well into breast milk and with it it can enter the body of a newborn. As well as increased hypersensitivity to substances that are part of the medication.

• Captopril

If the cause of taste disturbance is a malfunction of the kidneys, the doctor prescribes a daily dose (for a non-severe form of the disease) of 75–100 mg. For more severe manifestations of the disease, the daily dose is initially reduced to 12.5-25 mg and only after some time the attending physician gradually begins to increase the amount of the drug. For elderly people, the doctor selects the dosage individually, starting from 6.25 mg, and you must try to keep it at this level. Reception is carried out twice a day.

This drug is not recommended for use if there is an intolerance to one or more of the components included in the drug, as well as in cases of obvious disturbances in the functioning of the liver and kidneys. Take very carefully, only under the supervision of a doctor, to persons with aggravated diseases. of cardio-vascular system. Not recommended for children under 18 years of age, as well as for pregnant and nursing mothers.

• Methicillin

Or the scientific name is methicillin sodium salt. It is prescribed only intramuscularly.

The drug solution is prepared immediately before use. 1.5 ml of special water for injections, or a 0.5% novocaine solution, or a sodium chloride solution is injected into a bottle with 1.0 g of methicillin using a needle.

Adults are given an injection every four to six hours. In case of severe manifestations of the disease, the dosage of the drug can be increased from one to two grams.

For infants (up to 3 months), the daily dosage is 0.5 g.

For children and adolescents under 12 years of age, this drug is prescribed per kilogram of the child’s weight - 0.025 g. Injections are given after six hours.

Children who have crossed the 12-year mark - 0.75–1.0 g of methicillin sodium salt in solution every six hours, or the adult dosage.

The course of treatment is dictated by the severity of the disease.

Limit the use of this drug to persons suffering from individual intolerance to penicillin.

• Ampicillin

Reception of this medicine not tied to food intake. An adult can take 0.5 g once, but the daily dosage can be indicated as 2 - 3 g. For children under four years of age, the daily dosage is calculated per kilogram of the baby’s weight and is 100–150 mg (divided into four to six doses). The course of treatment is individual, prescribed by the attending physician and lasts from one to three weeks.

This drug is quite insidious in terms of side effects: gastrointestinal tract (exacerbation of gastritis), stomatitis, dysbacteriosis, diarrhea, nausea with vomiting, sweating, abdominal pain and many others. This drug is contraindicated in children under three years of age; at hypersensitivity to the components of the drug, pregnant women and breastfeeding mothers.

Such patients are also required to be prescribed immunostimulants in order to push the patient’s body to resist the disease.

• Immunal

The solution is prepared immediately before use by diluting the solution with a small amount of boiled water. The dosage is individual and designed for each age. Take orally, three times a day.

• Children from one to six years old - 1 ml of solution.
• Adolescents aged six to 12 years – 1.5 ml.
• Adults and adolescents over 12 years old – 2.5 ml.

The medicine can also be taken in tablets:

• Children from one to four years old. Crush one tablet and dilute with a small volume of water.
• Children from four to six years old - one tablet one to two times a day.
• Adolescents from six to 12 years old - one tablet one to three times a day.
• Adults and adolescents over 12 years of age – one tablet, three to four doses per day.

The course of treatment is at least one week, but no more than eight.

Immunal is contraindicated for use in the following cases: children under one year old (when taking solution) and up to four years old (when taking tablets), hypersensitivity to the components of the drug, as well as plants of the Asteraceae family; for tuberculosis; leukemia; HIV infections and others.

• Timalin

It is administered intramuscularly. The solution is prepared immediately before injection: the volume of one bottle is diluted to 1 - 2 ml isotonic solution sodium chloride. The mixture is shaken until completely dissolved.

The drug is administered:

• toddler up to one year - 5 - 20 mg. Daily.
• For a child one to three years old - 2 mg throughout the day.
• Preschoolers four to six years old – 3 mg.
• Teenagers seven - 14 years old - 5 mg.
• Adults – 5 – 20 mg daily. The general treatment course is 30 – 100 mg.

Duration of treatment is from three to ten days. If necessary, treatment can be repeated after a month.

Some special contraindications This drug has no other than individual intolerance to its components.

If the cause of the taste disorder is a zinc deficiency in the body, then the patient, apparently, will only need to drink some kind of zinc preparation. For example, zinkteral.

• Zincteral

A tablet that should not be chewed or split. Adults should take it one hour before meals three times a day, or two hours after meals. Gradually, as taste perception is restored, the dosage can be reduced to one tablet per day. For children over four years of age, the dosage is one tablet per day. There are practically no contraindications for this drug, except for hypersensitivity to the components that make up the drug.

If it turns out that the cause of the loss of taste perception is smoking, then you will have to rip out one thing: either smoke and not feel the delights of taste, or quit smoking and regain the “taste of life”.

Prevention

It's quite difficult to decide preventive measures, if the cause of taste disturbance can be such a huge number of diseases that are different in both genesis and severity. And yet, prevention of taste disorders is possible.

• Maintaining a healthy lifestyle. For example, smoking or alcohol can be one of the reasons for a violation of taste preferences.
• Increasing the quantity and variety of spices consumed. Excellent training of the receptor apparatus.

Don't forget about personal hygiene:

• Brushing your teeth morning and evening.
• Toothbrush and paste must be selected correctly.
• Rinsing the mouth after each meal, which, if not removed, begins to rot, creating favorable conditions for the development of pathogenic bacteria.
• You should wash your hands not only before eating, but also after visiting the toilet, and upon coming home from the street.
• Preventative visits dentist Complete sanitation of the oral cavity is a good barrier in the fight against infectious and fungal diseases.
• The diet should be harmoniously balanced. It must contain a sufficient amount of minerals and vitamins.
• If necessary, as prescribed by the doctor, you must take zinc and iron supplements.
• If the disease occurs, it must be treated “without delay.” long box“, and the course must be completed to the end, thereby eliminating all the causes of taste disturbance.

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Most women, in life, have a sweet tooth (this is their genetic predisposition), and this gene is double. Therefore, their taste palette is richer, and they can easily distinguish dozens of tones and half-tones of sweetness. People with a sweet tooth are less committed fatty foods, because they are less likely to suffer from diseases such as heart attack or stroke.

To one degree or another, taste disturbances are a fairly common phenomenon in our lives. It may arise for a short time, due to some everyday reasons, or it may “become friends” with you for a long time. In any case, do not let the situation take its course and do not brush it off. After all, this seemingly minor deviation from the norm may be one of the symptoms of a serious illness. And it depends only on you how quickly doctors can diagnose the disease and begin treating it. Take care of yourself and be more attentive to your health - after all, it is the most valuable and expensive thing you have!

Smell is one of the senses a person needs to live a full life. And its violations impose significant restrictions on emotional condition and become a real problem. Among the disorders of smell, there are also those when the patient is haunted by a smell that actually does not exist. Everyone is interested in the question of the origin of unpleasant symptoms, but only a doctor can help determine the source of disorders in the body.

Smell is perceived through the reaction of olfactory receptors located in the mucous membrane of the nasal cavity to certain aromatic molecules. But this is only the initial section of the corresponding analyzer. Next, the nerve impulse is transmitted to the areas of the brain responsible for the analysis of sensations (temporal lobes). And when a person smells odors that are not there, this clearly indicates some kind of pathology.

First of all, you should divide all the reasons into two groups. The smell may be very real, but is not felt by others until the patient speaks to them at close range. This is likely in the following situations, covering the practice of ENT doctors and dentists:

• Fetid runny nose (ozena).
• Sinusitis (sinusitis, sinusitis).
• Chronic tonsillitis.
• Caries, pulpitis, periodontitis.

These diseases are accompanied by the formation of pus, which gives an unpleasant odor. A similar situation may occur in those who suffer from diseases of the gastrointestinal tract (gastritis, peptic ulcer, cholecystitis and pancreatitis). Food caught in digestive tract, is processed worse, and during belching or reflux, molecules of unpleasant aroma come out. A similar problem may not be noticeable to others if they do not get close.

Some people have a lower olfactory threshold. They smell better than others, so sometimes they encounter misunderstandings from others. Some aroma may be too weak to be detected by anyone else. And this feature should also be taken into account by the doctor.

A separate group of causes are those that are associated with damage to any of the sections of the olfactory analyzer. The emerging odors do not reach others, since their formation, transmission and analysis in a particular person are disrupted. And although the basis for an unpleasant aroma may be some other (quite real), but final result is present only in the patient’s consciousness and poses a problem specifically for him.

There are quite a lot of conditions manifested by impaired sense of smell (dysosmia or parosmia). They include both respiratory pathology with inflammation of the nasal mucosa, for example, rhinitis or ARVI, and other disorders in the body:

• Hormonal changes (during pregnancy, during menstruation or menopause).
• Bad habits (smoking, alcohol abuse, drugs).
• Taking certain medications and chemical poisoning.
• Endocrine disorders (hypothyroidism, diabetes mellitus).
• Systemic diseases (scleroderma).
• Traumatic brain injuries.
• Brain tumors.
• Neuroses or depression.
• Psychosis (schizophrenia).
• Epilepsy.

It is also necessary to remember about the so-called phantom odors, which are associated with some kind of stress in the past and left a strong impression. In similar situations they can come to the surface. As we can see, the source unpleasant odor may be hiding among large number diseases. And some can be quite serious. But you shouldn’t immediately get scared and look for a dangerous pathology - the causes of the disorders will become clear only after a thorough examination.

Why people imagine certain smells is a rather serious question and requires further research.

Symptoms

Any pathology has certain signs. To identify them, the doctor evaluates the patient's complaints, analyzes the factors that precede the appearance of an unpleasant odor, and conducts a physical examination. You should understand when an extraneous odor is felt, whether it is constantly present or occurs periodically, how intense it is, what contributes to its disappearance and what additional symptoms there are in clinical picture. Sometimes this alone makes it possible to establish the cause of dysosmia, but not always.

The aroma that haunts the patient may have different colors. Those who drink citrus tea often feel a foreign burning smell, and hot spices can cause a feeling of the presence of sulfur in them. Simultaneously with the distortion of smell, taste also changes, since they are closely related. Severe runny nose, for example, can create the illusion that the onion has become sweet and smells like an apple.

ENT pathology

The first thing you should think about when complaining of an unpleasant odor is diseases of the ENT organs. When the nasal mucosa is damaged, the sense of smell is invariably impaired, but the patient may not always feel the smell of pus or rot. Most often, a similar symptom occurs with sinusitis, chronic tonsillitis or ozena. In the latter case, the smell is so pronounced that others notice it. But besides this, you need to pay attention to other symptoms:

• Impaired nasal breathing.
• Nasal discharge (mucopurulent or purulent).
• Heaviness in the projection of the paranasal sinuses.
• Dry mucous membranes and crusting.
• Sore throat when swallowing.
• Traffic jams on the tonsils.

If we are talking about acute sinusitis, then the purulent process in the sinuses invariably entails an increase in temperature and intoxication with headaches, but chronic sinusitis gives less pronounced symptoms. With tonsillitis, disorders of the kidneys, heart, and joints are often detected (the result of sensitization to streptococcal antigens). If the sense of smell is impaired due to ARVI, then in the clinical picture, in addition to a runny nose, against the background of intoxication there will be other catarrhal symptoms, for example, redness of the throat and lacrimation.

Pathology of the nose, paranasal sinuses and pharynx is the main cause of the appearance of a foreign odor, which can be perceived by others only upon close contact with the patient.

Digestive tract diseases

An unpleasant odor can also haunt those who suffer from diseases of the gastrointestinal tract. Impaired digestion of food is the main mechanism of this symptom. The smell of rotten eggs is disturbing with hypoacid gastritis (with reduced acidity) or peptic ulcer duodenum, he does not appear constantly, but after eating. The clinical picture also contains other signs of dyspeptic syndrome:

• Belching.
• Nausea.
• Bloating.
• Changing the stool.

Many people feel discomfort in the stomach or pain in the epigastrium. And concomitant gastroesophageal reflux causes heartburn and further esophagitis. If you are struck gallbladder, then an additional symptom will be a feeling of bitterness in the mouth.

Psychoneurological problems

Many patients with neuropsychiatric status disorders perceive an odor that is not really there. It can have either a real prototype (illusion) or be based on non-existent connections (hallucination). The first situation can also arise in healthy person who has suffered severe emotional stress, but often becomes a constant companion of those who suffer from neurosis or depression. Additional symptoms pathologies become:

• Decreased mood.
• Emotional lability.
• Irritability and anxiety.
• Feeling of a “lump” in the throat.
• Sleep disorders.

Characteristic signs will also be somatic functional disorders that arise due to an imbalance of nervous regulation (increased heart rate, increased sweating, nausea, shortness of breath, etc.). Unlike neurotic reactions, psychoses are accompanied by profound changes in the personal sphere. Then there are various hallucinations (auditory, visual, olfactory), overvalued and delusional ideas, when the perception of the surrounding world and behavior are disrupted, and there is no critical understanding of what is happening.

The feeling that you suddenly began to smell like rotten meat can occur with epilepsy. Olfactory and gustatory hallucinations are a kind of “aura” that precedes a convulsive attack. This indicates the location of the focus of pathological activity in the temporal lobe cortex. After a few seconds or minutes, the patient develops a typical attack with clonic-tonic convulsions, short-term loss of consciousness, and tongue biting. A similar picture also occurs with a brain tumor of the corresponding localization or skull injuries.

Neuropsychic disorders, as a cause of foreign odor, are perhaps the most serious situation that cannot be ignored.

Additional diagnostics

Smells that others cannot smell are a reason for a detailed examination. It is possible to find out the cause of what is happening only on the basis of a comprehensive diagnosis using a laboratory and instrumental complex. Based on the doctor’s assumption based on the clinical picture, the patient is recommended to undergo additional procedures:

• General blood and urine analysis.
• Blood biochemistry (inflammatory markers, liver tests, electrolytes, glucose, hormonal spectrum).
• Nasal and throat swab (cytology, culture, PCR).
• Rhinoscopy.
• X-ray of the paranasal sinuses.
• Computed tomography of the head.
• Echoencephalography.
• Fibrogastroscopy.
• Ultrasound of the abdominal organs.

To obtain maximum diagnostic value, the examination program is developed on an individual basis. If necessary, the patient consults not only an ENT doctor, but also other specialists: gastroenterologist, neurologist, endocrinologist, psychotherapist. And the results obtained make it possible to establish the final cause of the violations and eliminate the unpleasant odor that seemed to patients.

Senses of taste and sense of smell allow us to distinguish undesirable and even deadly food from tasty and nutritious food. Smell allows animals to recognize the proximity of other animals or even certain animals among many others. Finally, both senses are closely related to the primitive emotional and behavioral functions of our nervous system.

Taste is mainly a function of the taste buds of the oral cavity, but everyone knows from life experience that smell also makes a large contribution to the sensation of taste. In addition, the texture of food, sensed through the tactile receptors of the oral cavity, and the presence of substances in food that stimulate pain endings, such as pepper, significantly change taste perception. The importance of taste lies in the fact that it allows a person to choose food in accordance with desires, and often in connection with the metabolic needs of body tissues for certain substances.

Not all specific chemical substances, stimulating different taste buds are known. Psychophysiological and neurophysiological studies have identified at least 13 possible or probable chemical receptors in taste cells. Among them are 2 sodium receptors, 2 potassium receptors, 1 chloride receptor, 1 adenosine receptor, 1 inosine receptor, 2 sweet receptors, 2 bitter receptors, 1 glutamate receptor and 1 hydrogen ion receptor.

For practical taste analysis The potential capabilities of these receptors are grouped into five main categories, called primary taste sensations: sour, salty, sweet, bitter and umami.

A person can feel hundreds of different tastes. They are all supposed to be combinations of the primary taste sensations, just as all the colors we see are combinations of the three primary colors.

Sour taste. Sour taste is caused by acids, i.e. is related to the concentration of hydrogen ions, and the intensity of this taste sensation is approximately proportional to the logarithm of the concentration of hydrogen ions. This means that the more acid in food, the stronger the feeling of sourness.

Salty taste . The salty taste is associated with ionized salts, mainly the concentration of Na+ ions. The quality of taste varies from one salt to another, since some salts produce other taste sensations in addition to saltiness. Salt cations, especially Na+ ions, are mainly responsible for the feeling of saltiness, but anions also contribute, although to a lesser extent.

Sweet taste. The sweet taste is not associated with any one class of chemicals. Substances that cause this taste include sugars, glycols, alcohols, aldehydes, ketones, amides, esters, some amino acids, some small proteins, sulfonic acids, halogenated acids, and inorganic salts of lead and beryllium. Note that most of the substances that cause sweet taste are organic substances. It is especially interesting that a small change in the chemical structure, such as the addition of a simple radical, can often change the taste of a substance from sweet to bitter.

Bitter taste. Just like sweet taste, there is no one taste chemical substance causing a bitter taste. Again, almost all bitter-tasting substances are organic substances. Two specific classes of substances most likely cause bitter taste sensations: (1) long-chain organic matter containing nitrogen; (2) alkaloids. Alkaloids are found in many drugs used medically, such as quinine, caffeine, strychnine and nicotine.

Some substances first sweet to taste, have a bitter aftertaste. This is especially true for saccharin, for example, which makes the substance unpleasant for some people.

Bitter taste high intensity usually causes a person or animal to refuse food. This is undoubtedly important function bitter taste, since many of the deadly toxins found in poisonous plants are alkaloids, and virtually all of them have an intensely bitter taste, which usually leads to avoidance of foods containing them.

Taste of umami. Yumami is a Japanese word (meaning "very tasty"), indicating a pleasant taste sensation that is qualitatively different from sour, salty, sweet or bitter. Yumami is the primary taste of foods containing L-glutamate, such as meat extracts and aged cheese, and is considered by some physiologists to be a separate, fifth category of primary taste stimuli.

Taste receptor for L-glutamate, possibly associated with one of the glutamate receptors expressed at nerve synapses in the brain. However, accurate molecular mechanisms The factors responsible for the umami taste are not yet clear.

Educational video of the anatomy of the taste analyzer pathway

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