What is human saliva. Protein composition of mixed human saliva: mechanisms of psychophysiological regulation

1. Digestive function saliva is expressed in the fact that it wets the food bolus and prepares it for digestion and swallowing, and saliva mucin glues a portion of food into an independent lump. More than 50 enzymes were found in saliva, which belong to hydrolases, oxidoreductases, transferases, lipases, isomerases. Small amounts of proteases, peptidases, acid and alkaline phosphatases were found in saliva. Saliva contains the enzyme kallikrein, which is involved in the formation of kinins, which dilate blood vessels.

Even though food is in the mouth a short time- about 15 s, digestion in the oral cavity has great importance for the implementation of further processes of splitting food, since saliva, by dissolving food substances, contributes to the formation of taste sensations and affects appetite. In the oral cavity, under the influence of saliva enzymes, the chemical processing of food begins. saliva enzyme amylase breaks down polysaccharides (starch, glycogen) to maltose, and the second enzyme - maltase - breaks down maltose to glucose.

2. Protective function saliva is expressed as follows:

Saliva protects the oral mucosa from drying out, which is especially important for a person who uses speech as a means of communication;

The protein substance of saliva, mucin, is able to neutralize acids and alkalis;

Saliva contains an enzyme-like protein lysozyme(muramidase), which has a bacteriostatic effect and takes part in the processes of regeneration of the epithelium of the oral mucosa;

The nuclease enzymes contained in saliva are involved in the degradation of nucleic acids of viruses and thus protect the body from viral infection;

Blood coagulation factors were found in saliva, the activity of which determines local hemostasis, processes of inflammation and regeneration of the oral mucosa;

A substance stabilizing fibrin was found in saliva (similar to factor XIII in blood plasma);

Substances that prevent blood clotting (antithrombinoplastins and antithrombins) and substances with fibrinolytic activity (plasminogen and DR.) were found in saliva;

Saliva contains a large number of immunoglobulins, which protects the body from the ingress of pathogenic microflora.

3. Trophic function saliva. Saliva is a biological medium that comes into contact with tooth enamel and is the main source of calcium, phosphorus, zinc and other trace elements for it.

4. excretory function saliva. As part of saliva, metabolic products can be released - urea, uric acid, some medicinal substances, as well as salts of lead, mercury, etc.

Salivation is carried out by a reflex mechanism. There are conditioned reflex and unconditioned reflex salivation.

Conditioned reflex salivation is caused by the sight, smell of food, the sound stimuli associated with food preparation, as well as talking and remembering food. At the same time, visual, auditory, olfactory receptors are excited. Nerve impulses from them enter the cortical section of the corresponding analyzer, and then to the cortical representation of the center of salivation. From it, excitation goes to the bulbar department of the salivation center, the efferent commands of which go to the salivary glands.

unconditioned reflex salivation occurs when food enters the mouth. Food irritates the mucosal receptors. The afferent pathway of the secretory and motor components of the chewing act is common. Nerve impulses travel along afferent pathways to salivation center, which is located in the reticular formation of the medulla oblongata and consists of the upper and lower salivary nuclei (Fig. 32).

Rice. 32. Morphological structures providing the salivary reflex (scheme).

1-language;

2-drum string;

3-lingual nerve;

4-glossopharyngeal nerve;

5-upper laryngeal nerve;

6-sensitive ganglia of the corresponding nerves;

7-sensitive nuclei of afferent nerves;

8-way to the overlying parts of the central nervous system;

9-paths from the overlying parts of the central nervous system;

10-upper salivary nucleus;

11-lower salivary nucleus;

12-small stony nerve;

13-drum string;

14-ear autonomic ganglion;

15-submandibular vegetative ganglion;

16-hyoid autonomic ganglion;

17-ear temporal nerve;

18-drum string;

19-parotid salivary gland;

20-submandibular salivary gland;

21-sublingual salivary gland;

22-lateral horns of thoracic segments spinal cord(II-VI);

23-upper cervical sympathetic node;

We regularly swallow saliva. And we are used to the fact that the oral cavity is always wet and the cessation of sufficient production of this biological fluid is perceived with suspicion. As a rule, increased dryness in the mouth is a sign of a disease.

Saliva is a habitual and necessary biologically active liquid. Helps maintain the level of immune protection in the oral cavity, digestion of food. What is the composition of human saliva, fluid production rates, and physical and chemical properties?

Saliva is a biological substance secreted by the salivary glands. Fluid is produced by 6 large glands - submandibular, parotid, sublingual - and many small ones located in the oral cavity. Up to 2.5 liters of fluid is released per day.

The composition of the secretions of the salivary glands differs from the composition of the fluid in. This is due to the presence of food debris, the presence of microorganisms.

Functions of the biological fluid:

• wetting the food bolus;
• disinfecting;
• protective;
• promotes articulation and swallowing of the food bolus;
• breakdown of carbohydrates in the oral cavity;
• transport - the liquid wets the epithelium of the oral cavity and is involved in the metabolism between saliva and the mucous membrane of the oral cavity.

The mechanism of saliva production

Physical properties and composition of saliva

The biological fluid healthy person has a number of physical and chemical properties. They are presented in the table.

Table 1. Normal characteristics of saliva.

The main component of the oral fluid is water - up to 98%. The remaining components can be conditionally divided into acids, minerals, trace elements, enzymes, metal compounds, organics.

Organic composition

The vast majority of components of organic origin that make up saliva are of a protein nature. Their number varies from 1.4 to 6.4 g/l.

Types of protein compounds:

• glycoproteins;
• mucins - high molecular weight glycoproteins that ensure the ingestion of a food bolus - 0.9–6.0 g / l;
• immunoglobulins of class A, G and M;
• whey protein fractions- enzymes, albumins;
• salivoprotein - a protein involved in the formation of deposits on the teeth;
• phosphoprotein - binds calcium ions with the formation of tartar;
• - participates in the processes of splitting di- and polysaccharides into smaller fractions;
• maltase is an enzyme that breaks down maltose and sucrose;
• lipase;
• proteolytic component - for the breakdown of protein fractions;
• lipolytic components - act on fatty foods;
• lysozyme - has a disinfecting effect.

In the discharge of the salivary glands, insignificant amounts of cholesterol, compounds based on it, and fatty acids are found.

The composition of saliva

In addition, hormones are present in the oral fluid:

• cortisol;
• estrogens;
• progesterone;
• testosterone.

Saliva is involved in the wetting of food and the formation of a food bolus. Already in the oral cavity, enzymes break down complex carbohydrates into monomers.

Mineral (inorganic) components

Inorganic fractions in saliva are represented by acidic salt residues and metal cations.

The mineral composition of the secretion of the salivary glands:

• chlorides - up to 31 mmol / l;
• bromides;
• iodides;
• oxygen;
• nitrogen;
• carbon dioxide;
• uric acid salts - up to 750 mmol / l;
• anions of phosphorus-containing acids;
• carbonates and bicarbonates - up to 13 mmol / l;
• sodium - up to 23 mmol / l;
• – up to 0.5 mmol/l;
• calcium - up to 2.7 mmol / l;
• strontium;
• copper.

In addition, saliva contains small amounts of vitamins of various groups.

Composition features

The composition of saliva can change with age, as well as in the presence of diseases.

The chemical composition of the oral fluid varies depending on the age of the patient, his current condition, the presence of bad habits, the speed of its production.

Saliva is a dynamic fluid, that is, the ratio of various substances varies depending on what kind of food is in the oral cavity at the current time. For example, the use of carbohydrates, sweets contributes to an increase in glucose and lactate. Smokers have elevated levels of radon salts, unlike non-smokers.

A person's age has a significant effect. So, in older people, the level of calcium in the salivary fluid rises, which provokes the formation of tartar on the teeth.

Changes in quantitative indicators depend on general condition a person, the presence of chronic pathologies or an inflammatory process in the acute stage. Also, drugs taken on an ongoing basis have a significant impact.

For example, with hypovolemia, diabetes there is a sharp decrease in the production of secretion of the salivary glands, but the amount of glucose increases. With kidney disease - uremia various genesis- Nitrogen levels increase.

During inflammatory processes in the oral cavity, there is a decrease in lysozyme with an increase in enzyme production. This aggravates the course of the disease and contributes to the destruction of periodontal tissues. The lack of oral fluid is a cariogenic factor.

Subtleties of saliva secretion

0.5 ml of saliva per minute should be produced in a healthy person during the daytime

The work of the salivary glands is controlled by the autonomic nervous system with a center in medulla oblongata. The production of salivary fluid varies depending on the time of day. At night and during sleep, its amount decreases sharply, during the daytime it increases. In a state of anesthesia, the work of the glands completely stops.

During wakefulness, 0.5 ml of saliva is secreted per minute. If the glands are stimulated - for example, during meals - they produce up to 2.3 ml of liquid secretion.

The composition of the discharge of each gland is different. When it enters the oral cavity, mixing occurs, and it is already called "oral fluid". Unlike the sterile secretion of the salivary glands, it contains useful and conditionally pathogenic microflora, metabolic products, desquamated epithelium of the oral cavity, which is separated from maxillary sinuses, sputum, red and white blood cells.

The pH indicators are influenced by compliance with hygiene requirements, the nature of the food. So, when stimulating the work of the glands, the indicators shift to the alkaline side, with a lack of fluid - to the acidic side.

With various pathological processes, there is a decrease or increase in the secretion of oral fluid. So, with stomatitis, neuralgia of the branches trigeminal nerve, various bacterial diseases hyperproduction is observed. At inflammatory processes in respiratory system, the production of salivary gland secretion is reduced.

Some Conclusions

1. Saliva is a dynamic fluid that is sensitive to all processes occurring in the body at the current time.
2. Its composition is constantly changing.
3. Saliva performs many functions, in addition to wetting the oral cavity and food bolus.
4. Changes in the composition of the oral fluid may indicate pathological processes occurring in the body.

Instructions for use, saliva:

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  Human small intestine: anatomy, functions and process…

Saliva is a biological fluid secreted by three pairs of major salivary glands (parotid, submandibular, and sublingual) and hundreds of minor salivary glands. The secret of the salivary glands is supplemented by blood serum components, intact or destroyed cells of the mucous membranes, immune cells, as well as intact or destroyed microorganisms of the oral cavity. All this defines saliva as a complex mixture of various components. Saliva plays an important role in the formation of acquired plaque on the surface of the teeth, and due to its lubricating effect, it is involved in maintaining the integrity of the oral and upper gastrointestinal mucosa. Saliva also plays an important role in physicochemical defense, antimicrobial defense, and oral wound healing. Many components of saliva, including proteins, carbohydrates, lipids, and ions, are finely regulated to fulfill certain biological functions of saliva. Violation of the complex balanced composition of saliva leads to damage to the mucous membrane of the mouth and teeth.

Saliva functions are normal

• Moisturizing
• cleansing
• Lubrication
• Digestion
• Remineralization of the dental system
• (maintaining pH due to buffering properties)
• Maintaining the integrity of the mucous membranes
• immune protection
• Antimicrobial protection (antifungal, antibacterial)
• Stimulation of minor salivary glands
• Facilitate swallowing
• Taste
• Speech articulation

saliva production

is under the control of the autonomic nervous system (Fig. 1).

According to the type of secretion, the salivary glands are divided into

Serous: the secretion is very thin and watery

• parotid glands
• minor glands of the tongue - Ebner's serous glands

• palatine glands
• posterior lingual glands
• labial minor salivary glands

Mixed secretion: the secret of a mixture of two

• sublingual glands - mostly mucus with some serosity
• submandibular glands - mostly serous with some mucus
• Anterior lingual glands - mixed secretion. The mucosal glands are innervated by the sympathetic division of the autonomic nervous system, and the serous glands by the parasympathetic (Fig. 1).

Salivary glands are classified into large small

Large glands secrete saliva intermittently (Fig. 2). Small glands secrete saliva constantly.

parotid glands

The largest of the 3 major glands. Produce 30% of the total volume of saliva produced. The ducts of the parotid glands open into the oral cavity at the level of the maxillary second molars. Innervated by the sympathetic and parasympathetic divisions. They secrete saliva of the serous type.

submandibular glands

The second largest salivary glands. Produces 65-70% of the total volume of secreted saliva. The channel of the gland is called the submandibular duct, it opens at the top of the sublingual papillae. Located in a recess on the lingual side of the lower jaw.
They are innervated by parasympathetic nerves and do not have receptors for sympathetic nerves. Mixed secretion - mostly serous.

sublingual glands

The smallest of the major glands. They produce less than 5% of the total secreted saliva. Saliva enters the oral cavity through the Bartholin canals, which open in the sublingual fold. Innervated by parasympathetic fibers. Little or no sympathetic influence. Mixed secretion - mainly mucosal (mucous).

Minor salivary glands

Found throughout the mouth:

• The mucous membrane of the oral cavity (cheeks)
• Floor of the mouth
• The minor salivary glands play an important role in the formation of saliva.

Salivation (flow of saliva)

Basal secretion (salivation without external stimulus) is usually 0.2 ml - 0.3 ml per minute. If it is less than 0.1 ml per minute, then this means that the person has hyposalivation. Hyposalivation - insufficient production of saliva.

Stimulated salivation - response to a stimulus, usually taste, chewing or, for example, during a meal, medication - usually from 1.5 ml - 2 ml per minute. If the stimulated flow of saliva is less than 0.7 ml per minute, then they speak of hyposalivation.

On average, a person produces approximately 0.5 liters - 1.5 liters of saliva per day.
Salivation is determined by the time of day (Fig. 3). Salivary flow decreases at night.

The composition of saliva

90% of saliva is water. 10% - inorganic and organic ions and cellular components. Sodium, potassium, calcium are positive ions (cations), chloride, bicarbonate and phosphates are negative ions (anions). Cationic and anionic components play an important role in the function of saliva. Fluoride is also secreted into saliva. Unlike other salivary ions, the fluoride content (level) in basal and stimulated saliva does not change.

Organic components of saliva

Enzymes:

• Amylase - conversion of starch to glucose and fructose
• Lysozyme - prevents bacterial infections in the mouth
• Histatins - prevent fungal infections
• Secretory IgA - immune mediator
• Lactoperoxidase - stimulation of minor salivary glands
• RNases and DNases - cellular contents
• Lipase - initiates the digestion of fats
• Kallikrein is a regulator of vascular tone.

Cellular composition of saliva

• epithelial cells
• Neutrophils
• Lymphocytes
• bacterial flora.

Saliva is 98% water, but other substances dissolved in it provide a characteristic viscous consistency. The mucin in it sticks together pieces of food, moistens the resulting lumps and helps with swallowing, reducing friction. Lysozyme is a good antibacterial substance that copes well with pathogenic microbes that enter the mouth along with food.

The enzymes amylase, oxidase and maltase already at the stage of chewing begin to digest food - first of all, they break down carbohydrates, preparing them for the further process of digestion. There are also other enzymes, vitamins, cholesterol, urea and many different elements. Salts of various acids are also dissolved in saliva, which provide it with a pH level of 5.6 to 7.6.

One of the main functions of saliva is to moisten the mouth to aid in articulation, chewing and swallowing. Also, this liquid allows the taste buds to perceive the taste of food. Bactericidal saliva cleanses the oral cavity, protects teeth from caries, and the body from infections. It heals wounds on the gums and palate, washes out bacteria, viruses and fungi from the spaces between the teeth.

The composition of saliva in the oral cavity differs from the secret contained in the salivary glands, as it mixes with microorganisms and other substances that enter the mouth with food, dust, and air.

saliva production

Saliva is produced by special salivary glands, which are found in large numbers in the oral cavity. There are three pairs of the largest and most significant glands: these are the parotid, submandibular and sublingual, they produce most of the saliva. But other, smaller and more numerous glands are also involved in the process.

The production of saliva begins at the command of the brain - its area called the medulla oblongata, where the centers of salivation are located. In certain situations - before eating, during stress, when thinking about food - these centers begin their work and send a command to the salivary glands. When chewing, especially a lot of saliva is secreted, as the muscles squeeze the glands.

During the day, the human body produces from one to two liters of saliva. Its quantity is influenced by various factors: age, quality of food, activity and even mood. So, with nervous excitement, the salivary glands begin to work more actively. And in a dream, they almost do not salivate.

Digestion begins in the oral cavity, where the mechanical and chemical processing of food takes place. Mechanical processing consists in grinding food, wetting it with saliva and forming a food lump. Chemical processing occurs due to enzymes contained in saliva. The ducts of three pairs of large salivary glands flow into the oral cavity: parotid, submandibular, sublingual and many small glands located on the surface of the tongue and in the mucous membrane of the palate and cheeks. The parotid glands and glands located on the lateral surfaces of the tongue are serous (protein). Their secret contains a lot of water, protein and salts. The glands located on the root of the tongue, hard and soft palate, belong to the mucous salivary glands, the secret of which contains a lot of mucin. The submandibular and sublingual glands are mixed.

Digestive enzymes are divided into four groups. Proteolytic enzyme: proteins compartments for amino acids Lipolytic enzyme: fats divided into fatty acids and glycerol.

• Amylolytic enzyme: breaks down carbohydrates and starch into simple sugars.
• Nucleolytic enzyme: breaks down nucleic acids into nucleotides.

Composition and properties of saliva.

The saliva in the oral cavity is mixed. Its pH is 6.8-7.4. In an adult, 0.5-2 liters of saliva is formed per day. It consists of 99% water and 1% solids. The dry residue is represented by organic and inorganic substances. Among inorganic substances - anions of chlorides, bicarbonates, sulfates, phosphates; cations of sodium, potassium, calcium, magnesium, as well as trace elements: iron, copper, nickel, etc. The organic substances of saliva are represented mainly by proteins. The protein mucous substance mucin sticks together individual food particles and forms a food lump. The main enzymes of saliva are amylase and maltase, which act only in a slightly alkaline environment. Amylase breaks down polysaccharides (starch, glycogen) to maltose (disaccharide). Maltase acts on maltose and breaks it down to glucose.
Small amounts of other enzymes were also found in saliva: hydrolases, oxidoreductases, transferases, proteases, peptidases, acid and alkaline phosphatases. Saliva contains the protein substance lysozyme (muramidase), which has a bactericidal effect.
Food stays in the mouth for only about 15 seconds, so there is no complete breakdown of starch. But digestion in the oral cavity is very important, as it is the trigger for the functioning of the gastrointestinal tract and the further breakdown of food.

Stomach Enzymes secreted by the stomach are known as gastric enzymes. They are responsible for breaking down complex macromolecules such as proteins and fats into simpler compounds. Pepsinogen is the main enzyme in the stomach and is active form is pepsin.

Pancreas The pancreas is the repository of digestive enzymes and is the main digestive gland of our body. The digestive enzymes of carbohydrates and pancreatic molecules break down starch into simple sugars. They also secrete a group of enzymes that aid in the degradation of nucleic acids. It works both endocrine and exocrine. The digestive enzymes secreted by the pancreas are listed in the following table.

Functions of saliva

Saliva performs the following functions. Digestive function- it was mentioned above.
excretory function. Some metabolic products, such as urea, uric acid, medicinal substances (quinine, strychnine), as well as substances that have entered the body (salts of mercury, lead, alcohol) can be released in saliva.
protective function. Saliva has a bactericidal effect due to the content of lysozyme. Mucin is able to neutralize acids and alkalis. Saliva contains a large amount of immunoglobulins, which protects the body from pathogenic microflora. Substances related to the blood coagulation system were found in saliva: blood coagulation factors that provide local hemostasis; substances that prevent blood clotting and have fibrinolytic activity; fibrin stabilizing agent. Saliva protects the oral mucosa from drying out.
trophic function. Saliva is a source of calcium, phosphorus, zinc for the formation of tooth enamel.

Small intestine The final stage of digestion is carried out small intestine. It contains a group of enzymes that are degradation products that are not digested by the pancreas. This happens just before the selection. Food is converted into a semi-solid form by the activity of enzymes present in the duodenum, jejunum, and ileum.

That is, they are carried later to the large intestine, from where they are expelled. First, let's remember what carbohydrates are. They are a group of foods that give us a great energy contribution immediately, they are also called carbohydrates or carbohydrates, which are widely distributed in plants and animals. Exist different types carbohydrates, which are classified according to their chemical structure and size. There is a large carbohydrate known as a polysaccharide, an example of this type is starch, the main component of potatoes.

Salivation regulation

When food enters the oral cavity, irritation of the mechano-, thermo- and chemoreceptors of the mucous membrane occurs. Excitation from these receptors along the sensory fibers of the lingual (a branch of the trigeminal nerve) and glossopharyngeal nerves, the tympanic string (a branch of the facial nerve) and the superior laryngeal nerve (a branch vagus nerve) enters the salivation center in the medulla oblongata. From the salivary center along the efferent fibers, excitation reaches the salivary glands and the glands begin to secrete saliva. The efferent pathway is represented by parasympathetic and sympathetic fibers. Parasympathetic innervation of the salivary glands is carried out by the fibers of the glossopharyngeal nerve and the tympanic string, sympathetic innervation - by fibers extending from the superior cervical sympathetic ganglion. The bodies of preganglionic neurons are located in the lateral horns of the spinal cord at the level of II-IV thoracic segments. Acetylcholine, which is released during irritation of the parasympathetic fibers that innervate the salivary glands, leads to the separation of a large amount of liquid saliva, which contains many salts and few organic substances. Norepinephrine, released when sympathetic fibers are stimulated, causes the separation of a small amount of thick, viscous saliva, which contains few salts and many organic substances. Adrenaline has the same effect. Substance P stimulates the secretion of saliva. CO2 enhances salivation. Painful stimuli, negative emotions, mental stress inhibit the secretion of saliva.
Salivation is carried out not only with the help of unconditioned, but also conditioned reflexes. The sight and smell of food, the sounds associated with cooking, as well as other stimuli, if they previously coincided with eating, talking and remembering food cause conditioned reflex salivation.
The quality and quantity of separated saliva depends on the characteristics of the diet. For example, when taking water, saliva almost does not separate. Saliva secreted into food substances contains a significant amount of enzymes, it is rich in mucin. When inedible, rejected substances enter the oral cavity, liquid and abundant saliva is released, poor in organic compounds.

The other smaller one is known as a disaccharide; an example of this is lactose, which is found in milk. Finally, among the smallest are monosaccharides such as fructose, which is present in honey and many fruits. It is a monosaccharide known as glucose, found in vegetables and blood. Glucose is first-hand the energy in the vast majority of the physical and chemical reactions that take place inside the cell.

It is obtained from plants from carbon dioxide and water through photosynthesis; It is stored as starch and used to make cellulose, which forms part of plant cell walls. And now, what happens to the carbohydrates we eat in the diet?

Digestion in the mouth and stomach is a complex process that involves many organs. As a result of such activity, tissues and cells are nourished, and energy is also provided.

Digestion is an interrelated process that provides mechanical grinding of the food bolus and further chemical breakdown. Food is necessary for a person to build tissues and cells in the body and as a source of energy.

Digestion of carbohydrates begins in the mouth with the help of mainly saliva. The largest volume occurs before, during and after meals, peaks at about 12 o'clock and decreases significantly at night, during sleep. Saliva has an enzyme called alpha-amylase, which is responsible for unfolding or breaking down starch and other polysaccharides in the diet into smaller molecules like glucose. This enzyme, since it is present in saliva, has been named "salivary α-amylase" or "ptyalin".

The enzyme α-amylase is not only found in saliva, it is also found in the pancreas, which is why it is called "pancreatic α-amylase". At this point, the enzyme is involved to a greater extent in the digestion of carbohydrates consumed by the diet. Another place where this enzyme can be found is in the blood, being removed through the kidney and excreted in the urine.

assimilation mineral salts, water and vitamins occurs in its original form, but more complex macromolecular compounds in the form of proteins, fats and carbohydrates require splitting into simpler elements. To understand how such a process occurs, let's analyze digestion in the oral cavity and in the stomach.

Before "plunging" into the process of cognition digestive system, you need to know about its functions:

This enzyme is known to originate from the salivary glands, which are found in all areas of the mouth, with the exception of chewing gum and the anterior part of the hard palate. It is sterile when it leaves the glands, but ceases immediately after it mixes with food debris and microorganisms. In particular, this enzyme plays an important role in infants younger than 6 months who have a delay in the production of pancreatic α-amylase. On the other hand, this enzyme helps digest carbohydrates in patients with pancreatic insufficiency.

• there is a production and release of digestive juices containing biological substances and enzymes;
• transfers decay products, water, vitamins, minerals, etc. through the mucous membranes of the gastrointestinal tract directly into the blood;
• secretes hormones;
• provides grinding and promotion of food mass;
• excretes the resulting end products of metabolism from the body;
• provides a protective function.

Attention: to improve the digestive function, it is necessary to monitor the quality of the products used, the price for them, although sometimes higher, but the benefits are much greater. It is also worth paying attention to the balance of nutrition. If you have digestive problems, it is best to consult a doctor about this issue.

Another function of the enzyme is that it participates in the colonization of bacteria involved in the formation of bacterial plaque. Although α-amylase is supposed to be multifunctional, only three important functions have been reported. This helps to break down the starch molecule into shorter units such as glucose and thus facilitate the process of carbohydrate digestion. The enzyme binds to another type of bacteria that help bacterial cleansing of our oral cavity.

• This acid contributes to the decay process.
• That's why you should brush your teeth!

As we have seen, the presence of the enzyme α-amylase in saliva is very important in the process of digestion.

Importance of Enzymes in the Digestive System

The digestive glands of the oral cavity and gastrointestinal tract produce enzymes that play one of the main roles in digestion.

If we generalize their meaning, then we can highlight some properties:

But it is also important to know at what point the salivary glands release this enzyme into the saliva. The regulation of the release of salivary alpha-amylase is carried out by the autonomic nervous system, which, in turn, is divided into sympathetic and parasympathetic. One way of activating the autonomic nervous system is stress, causing patients to experience rapid heartbeat, dizziness, pain, nervousness, agitation, irritability, restlessness, concentration problems, and low mood. Therefore, some researchers suggest that the amount of salivary alpha-amylase be changed through a saliva sample in order to determine the level of stress.

1. Each of the enzymes is highly specific, catalyzing only one reaction and acting on one type of bond. For example, proteolytic enzymes or proteases are able to break down proteins into amino acids, lipases break down fats into fatty acids and glycerol, amylases break down carbohydrates into monosaccharides.
2. They are able to act only at certain temperatures in the range of 36-37C. Anything that is outside these boundaries leads to a decline in their activity and disruption of the digestion process.
3. High "performance" is achieved only at a certain pH value. For example, pepsin in the stomach is activated only in an acidic environment.
4. They can break down a large amount of organic substances, since they are highly active.

Enzymes of the mouth and stomach:

In addition to stress, anxiety also alters the autonomic nervous system, pathologies that can be detected by changes in the amount of salivary alpha-amylase in adolescents. Then the detection of salivary α-amylase is a good diagnostic tool for stress, anxiety, and other types of changes.

In addition, saliva plays an important role in the digestion of carbohydrates that we ingest in the diet due to the presence of enzymes such as α-amylase. Finally, saliva is a hot topic of research because, as we have seen, it can be used as diagnostic method for physical and psychological stress, anxiety and disease through the detection of the α-amylase enzyme.

Attention: in the stomach, the activity of enzymes is increased due to the production of hydrochloric acid. This is an inorganic element that performs one of the important functions in digestion, contributing to the destruction of protein. It also disinfects pathogenic microorganisms that come with food and, as a result, prevents the possible decay of food masses in the stomach cavity.

Enzymes are catalysts of a protein nature that regulate the rate at which the physiological processes produced by living organisms are carried out. Therefore, deficiencies in enzymatic function cause pathology. It has two sides: the oral face, covered by the oral mucosa; and the nasal side, covered with the nasal mucosa. This can be a risk factor during a dental consultation if they are not properly treated with all the measures necessary for the well-being of the patient; since difficulties or complications may arise during the intervention; which will worsen the treatment to be carried out or in some cases lead to adverse effects. They group all infectious and inflammatory phenomena that affect the dentition and the periapical region. It is located in the head and makes up mainly the dental apparatus, as well as the first part of the digestive system. The mouth opens into a space in front of the pharynx, called the oral cavity, or oral cavity. Enzymes are highly reactive. The second characteristic of enzymes is their exceptional specificity. It has been suggested that each biochemical process has its own specific enzyme.

• It divides the pharynx into two parts: the nasal part and the oral part.
• In equity, the soft palate is very long.
• Soft palate completely isolates Airways from the digestive system.

Definitely in our career.

The role of enzymes in the body is multifaceted and this is evidenced by the photo below.

Digestion in the mouth

With a decrease in the concentration of nutrients in the blood, a feeling of hunger begins. The physiological basis of this feeling is localized in the lateral nuclei of the hypothalamus. It is the stimulation of the hunger center that is the motive for the search for food.

To our friends and colleagues for theirs. To our teachers for their wise teachings that will serve me in my professional life. People who with their help and guidance. made this report possible. In humans, digestion begins in the mouth, where there is food. chewed and degraded by enzymes contained in the secretion of saliva. secreted in the mouth in large quantities by the salivary glands, the main ones. they are parotid, submandibular and sublingual; Besides, there are a lot of them. small salivary glands The enzymes present in the oral cavity and which we will study are: amylase. saliva, which hydrolyzes starch, lysozyme, which disinfects possible bacteria. infectious, as well as lingual lipase, which is activated in the acidic environment of the stomach, which. it acts on triglycerides.

So, food is in front of our eyes, we tried its taste and got saturated, but I wonder what was happening in the body at that moment?

Initial department digestive tract is the oral cavity. From below, it is limited by the diaphragm of the mouth, from above by the palate (hard and soft), and from the sides and in front by the gums and teeth. Also here, the ducts of the digestive glands open into the oral cavity, these are the sublingual, parotid, submandibular.

The oral cavity is a cavity covered with a mucous membrane and its. borders. Excellent and language below. The walls of the mouth must withstand considerable friction with food, and so a mucous membrane is formed. stratified squamous epithelium instead of the typical columnar simple epithelium. In the gums, hard palate and dorsal part of the tongue, the epithelium is reinforced with a certain amount of keratin to provide. Extra protection against abrasion. The mucous membrane of the mouth forms the so-called defensins when.

Antimicrobial, which explains why the mouth, located on the "battle front", is so healthy. Sagittal part of the mouth. The lips are much longer than you might think and expand. the lower edge of the nose to the upper border of the chin. The reddish area that one kisses or paints with lipstick is called a red edge, and this is obtained. transition zone between keratinized skin and oral mucosa. The red field is poorly keratinized and transparent, which gives a red color. underlying capillaries are visible through it.

In addition, there are other mucous small salivary glands located throughout the oral cavity. After capturing a lump of food with teeth (and there are only 32 of them, 16 for the lower and 16 for the upper jaw), it is chewed and moistened with saliva, which contains the enzyme ptyalin.

It has the ability to dissolve some easily soluble substances, and soften and cover the food with mucus, which greatly facilitates the process of swallowing. Saliva also contains mucin with lysozyme, which have bactericidal effects.

With the help of the tongue, a muscular organ covered with a mucous membrane, taste is realized and food is pushed to the pharynx after chewing. Next, the prepared lump of food passes through the esophagus to the stomach.

Swallowing is a complex process that involves the muscles of the pharynx and tongue. During this movement, the soft palate rises, due to which the entrance to the nasal cavity and the path of food to this area is blocked. With the help of the epiglottis, the inlet to the larynx is closed.

Through the upper part of the digestive tract - the pharynx, the food bolus begins to move along the esophagus - a tube about 25 cm long, which is a continuation of the pharynx. The upper and lower esophageal sphincters open at this time, and the passage of food to the stomach itself takes about 3-9 seconds, liquid food moves in 1-2 seconds.

No changes occur in the esophagus, since digestive juices are not secreted there, the rest of the splitting stage will occur in the stomach. You can learn more about digestion in the oral cavity from the video in this article.

Digestion in the stomach

After the esophagus, the food bolus enters the stomach. This is the most expanded part of the gastrointestinal tract, having a capacity of up to 3 liters.

The shape and size of this organ can vary depending on the degree of muscle contraction and the amount of food consumed. The mucous membrane is formed by longitudinal folds containing a huge number of glands that produce gastric juice.

It is represented by three types of cells:

• main- these are those that produce enzymes of gastric juice;
• lining- they are able to produce hydrochloric acid;
• additional- with their help, mucus (mucoid and mucin) begins to be produced, thanks to which the walls of the stomach are protected from the action of pepsin.

If there is a violation of the secretion of gastric juice in the body, there are special preparations to normalize this process, which are accompanied by instructions for use. However, self-medication is not recommended, because this can cause complications.

The moment of penetration of gastric juice into the food mass implies the beginning of the gastric phase of digestion, during which the breakdown of protein particles occurs predominantly. This happens as a result well-coordinated work enzymes and stomach acid. The semi-digested food is then sent from the stomach to the duodenum through the pyloric sphincter, which completely separates the stomach and intestines during contraction.

The duration of food in the stomach cavity depends on its composition. Solid protein food stimulates the secretion of gastric juice more actively and stays in this organ longer, while liquid food leaves much faster.

On average, food can linger in the stomach for 4-6 hours. At the end of the digestion phase, it is in a collapsed state, and every 45-90 minutes periodic contractions of the stomach begin, the so-called hungry peristalsis.

As we understood, digestion is a complex multi-stage process regulated by the central nervous system departments. Each stage smoothly follows each other and many organs are involved in each of them. All this is regulated by the nervous and humoral regulation system.

However, any violation can cause a failure in automatic actions digestive system, which will entail certain symptoms and signs. In this case, you should immediately seek medical helpwhere the doctor can examine and prescribe the necessary diagnosis.