Process of digestion of nutrients. How does the human digestive system work?

The basic processes of food processing occur as a consequence of digestion within our digestive system. These are all organs whose role is mainly to process food chemically. Also digestive system promotes quality absorption useful substances and stops the entry of harmful food components, neutralizes and removes them.

Thanks to the work of the gastrointestinal tract, food is decomposed into elementary (including chemical) compounds. This happens for the best absorption of food. The digestive tract works like a food processing machine and tirelessly grinds all the food consumed by a person, secretes juices for its processing and mixes, and undergoes chemical treatment, thanks to which gastric juices cope with large quantities food you eat daily.

Sometimes it is very difficult for the reader to understand how the food you eat can support the functionality and vital activity of the entire body and feed it with useful substances. Now we will try to put everything “on the shelves” in a simple form of presentation and talk about the physiological process of assimilation and processing of food by different departments digestive tract.

Oral cavity

The oral cavity also belongs to gastrointestinal tract. Starting from the oral cavity, the food you eat begins to migrate throughout the body and be absorbed and processed. With the help of the tongue and teeth, the food is mixed and crushed to a homogeneous consistency, then they go on the attack salivary glands, with the help of which saliva enters the oral cavity, it moistens food.

By using salivary enzymes, which are called amylase, food begins to decompose. Then the person makes a difficult reflex function- swallowing. Swallowing moves food into the esophagus.

If a person chews food poorly, it is still not ready for digestion. Food must be thoroughly chewed and crushed; if this is not the case, a person may develop gastritis, constipation and suffer from other digestive tract problems.

The esophagus is a kind of corridor for a bolus of food to pass normally from the mouth to the stomach. The esophagus is a tube with walls that have several layers of muscle fibers.

Inside, this corridor consists of a mucous membrane that has useful property significantly facilitate the passage of food through it. Thanks to muscle fibers and mucous food also does not damage the walls of the esophagus. The esophageal tube can expand and contract as needed for the bolus to pass into the stomach. So she pushes it through.

Stomach

It is the stomach that grinds, grinds and helps digest food; the stomach performs the basic processes for processing the food consumed. Thanks to gastric juice, food is digested as efficiently as possible, and food is broken down into elementary chemical compounds.

Externally, the stomach is similar to a pouch, which increases or decreases due to the functional elasticity of the walls of which it consists. The capacity of the stomach can be very large capacity. The stomach holds about two kilograms of the food we eat. At the very end of the stomach there is a special valve called the sphincter. It protects against premature entry of food waste into the duodenum.

First layer of the stomach

The stomach has three main layers. The first layer is the inner one, it is called the “mucous membrane” of the stomach. This first lining consists of the gastric glands. The inside of the stomach wall is completely covered epithelial cells. Both epithelial cells and the walls of the stomach are very different in structure and perform completely different roles.

Some of them are able to secrete hydrochloric acid with digestive enzymes that secrete gastric juice. Some of the other cells secrete a mucous substance that coats the stomach walls and protects them from damage.

The mucous membrane has a submucosal base, a base. It is created like a track that is laid under the glands and epithelial cells. This foundation is permeated by many, many small blood vessels, nerves that make it possible to supply the stomach with blood, nerve cells– transmit the necessary impulses. For example, pain.

Second layer of the stomach

This second layer is muscle. The stomach has them too. The muscles of the stomach are its thin shell. It is folded in double or even triple layers, like puff pastry. The lining of the stomach helps grind food into a pulp. Just like a mixer. Mixing with gastric juice, food is effectively dissolved and then absorbed by the walls of the stomach.

Third layer of the stomach

And finally serosa the stomach is its third layer. It is created in the form of a thin fabric that lines the inside abdominal cavity. And not only her, but also internal organs, giving them the opportunity to be dynamic, active, mobile.

What happens in the stomach during digestion?

When food enters the stomach, gastric juices moisten it and help it dissolve. What is gastric juice? This is a viscous and thick liquid, produced by the glands of the gastric mucosa. It is difficult to describe the composition of gastric juice; it contains many components. Its most important components are digestive enzymes and hydrochloric acid. Of course, hydrochloric acid is a rather poisonous and burning substance that can dissolve many products. Therefore, the stomach walls would dissolve due to exposure of hydrochloric acid, if they were not protected by mucus. But digestive enzymes help acid dissolve foods more efficiently. These are chemically active substances.

For example, renin is capable of making cottage cheese from milk. Lipase is a substance that breaks down fats. But these enzymes do not have many functions, but they perform them thoroughly. The enzyme pepsin is more active in the stomach - its composition complements hydrochloric acid and can, in collaboration with it, break down proteins taken from plant and animal foods. The result is simpler chemical compounds - amino acids and peptides.

When the sphincter of the stomach relaxes, the food, which is already ready for the next stage of processing, enters further in the form of gruel into the lower regions of the digestive tract. And then the remnants of products, which are called chyme, continue to be digested, but in the intestines.

Intestines

The work of the intestines is also quite intense, and it is aimed at digesting and pushing food through. The intestines perform quite a few roles, and therefore they are designed as a complex natural structure. The intestine has several sections, determined anatomically. These are, first of all, its sections, such as the jejunum, cecum, duodenum, transverse, ascending, ileum, colon, sigmoid and finally the rectum. The anus is located in the lower intestine. Feces come out through it.

How does the intestine work?

It, like the stomach and esophagus, contracts and thus pushes food to its lower section, which ends in the anus. These intestinal contractions are called peristalsis. And doctors call the role of the intestines in pushing feces motor, in other words, intestinal motility. Have you heard this term? Externally, the intestines look like a pipeline through which food remains pass.

The intestine also has walls, like the stomach. And they also look like sheets laid on top of each other - muscle layers. This makes the intestinal walls elastic and flexible. These walls are the mucous membrane, serous and muscular layers.

When food in the form of liquid gruel passes through the intestines, it is simultaneously broken down by intestinal juice into amino acids and other compounds that have the simplest structure. In this form, food is easily absorbed by the elastic and strong walls of the intestines. These substances are carried through the blood and nourish the body. necessary elements, giving energy.

Please note: food is digested and absorbed, and also in the form feces passes into the anus through different departments intestines.

Duodenum

This very useful section of the intestine is almost 25 centimeters long. The duodenum performs a noble role - it controls the functioning of the stomach. He is located next to her, which is very convenient for their interaction.

The duodenum regulates the release of hydrochloric acid from the stomach to process food and also controls its motor and excretory functions.

When there is too much hydrochloric acid ( increased acidity), this becomes dangerous for the condition of the gastric mucosa - it can begin to self-digest, which is also quite painful. Therefore, the duodenum stops this process (secretion of acid by the stomach), transmitting the corresponding signal through the receptors. Simultaneously lower sections intestines receive a command about that. that now food will begin to move towards them - down from the stomach.

Bile also comes from the duodenum to break down food, which facilitates the digestion process. Then all elements of food can be digested - fats, carbohydrates, and proteins.

Small intestine

It is very long - from 4 meters to 7 meters. The small intestine follows, like a girlfriend, the duodenum. The small intestine includes two more sections of the intestine - the ileum and the jejunum. They play important roles in digestive processes. When food reaches these parts of the intestine, the food there is chemically treated with various chemicals and then begins to be absorbed by the intestinal walls. In particular, those substances that are beneficial to the body are absorbed.

Details of the small intestine

In these parts of the intestine - ileum and jejunum- food is absorbed in a very original way - not by the walls, but next to them. This process of absorption is called parietal. This role is performed by special agents – enterocytes. This is the name of the cells of the mucous membrane, which belongs to small intestine. These cells are capable of secreting substances that perfectly perform the role of breaking down glucose, amino acids and fatty acids, from which food consists.

And then the mucous membrane immediately absorbs these processed substances. But they are absorbed into different areas body. The blood absorbs glucose and amino acids, and the capillaries absorb fatty acids. And then these food elements move further in liquid form - to the liver.

The small intestine is so important to the body that its elimination during surgery leads to fatal outcome. The same cannot be said about the stomach, after part of which is removed a person lives on.

Most of the nutrients needed to support life human body receives through the gastrointestinal tract.

However regular products that a person eats: bread, meat, vegetables - the body cannot use directly for its needs. To do this, food and drinks must be divided into smaller components - individual molecules.

These molecules are carried by the blood into the body's cells to build new cells and produce energy.

How is food digested?

The process of digestion involves mixing food with gastric juices and moving it through the gastrointestinal tract. During this movement, it is disassembled into components that are used for the needs of the body.

Digestion begins in the mouth - by chewing and swallowing food. And ends in small intestine.

How does food move through the gastrointestinal tract?

The large, hollow organs of the gastrointestinal tract—the stomach and intestines—have a layer of muscle that moves their walls. This movement allows food and liquid to move through the digestive system and mix.

Contraction of the organs of the gastrointestinal tract is called peristalsis. It looks like a wave that moves along the entire digestive tract with the help of muscles.

The intestinal muscles create a constricted area that slowly moves forward, pushing food and liquid in front of it.

How does digestion happen?

Digestion begins in the oral cavity, when chewed food is abundantly moistened with saliva. Saliva contains enzymes that begin the breakdown of starch.

Swallowed food enters esophagus, which connects throat and stomach. At the junction of the esophagus and stomach there are circular muscles. This is the lower esophageal sphincter, which opens under the pressure of swallowed food and allows it to pass into the stomach.

The stomach has three main tasks:

1. Storage. To take in large amounts of food or liquid, the muscles in the upper part of the stomach relax. This allows the walls of the organ to stretch.

2. Mixing. Bottom part The stomach contracts to allow food and liquid to mix with gastric juices. This juice consists of hydrochloric acid and digestive enzymes, which help in the breakdown of proteins. The walls of the stomach secrete a large number of mucus, which protects them from the effects of hydrochloric acid.

3. Transportation. Mixed food passes from the stomach to the small intestine.

From the stomach, food enters upper section small intestine - duodenum . Here the food is exposed to juice pancreas and enzymes small intestine, which promotes the digestion of fats, proteins and carbohydrates.

Here food is processed by bile, which is produced by the liver. Between meals, bile is stored in gallbladder. During eating, it is pushed into the duodenum, where it mixes with food.

Bile acids dissolve fat in the intestinal contents in much the same way as detergents– fat from the frying pan: they break it into tiny droplets. Once the fat is crushed, it is easily broken down by enzymes into its components.

Substances that are obtained from food digested by enzymes are absorbed through the walls of the small intestine.

The mucous membrane of the small intestine is covered with tiny villi, which create a huge surface area that allows the absorption of large amounts of nutrients.

Through special cells, these substances from the intestines enter the blood and are carried throughout the body - for storage or use.

Undigested parts of food go to colon , in which water and some vitamins are absorbed. Digestive waste is then formed into feces and removed through rectum.

What disrupts the gastrointestinal tract?

The most important

The gastrointestinal tract allows the body to break down food into its simplest compounds, from which new tissue can be built and energy can be obtained.

Digestion occurs in all parts of the gastrointestinal tract - from the mouth to the rectum.

There is a rule: if you want to get the most accurate information, consult the reference book. So let's open the 24th volume of the Big medical encyclopedia and on page 603 we read: “Digestion - First stage metabolism in the body, which consists in the physical and chemical processing of food.” Isn't it very difficult?

Indeed, dear reader, we believe that neither in the dining room where you run into lunch break, neither at home after work, when you have dinner with appetite, nor in a restaurant, where you sometimes sit with friends, it never occurs to you that you are performing the “initial stage of metabolism in the body.” We think that you also do not suspect that your essence changes depending on which side you look at. For yourself - you are a person, for a waiter in a restaurant - a client, for your comrades sitting at the restaurant table with you - a pleasant interlocutor and your own person, but from the point of view digestive process you are a heterotrophic organism, unable to synthesize organic compounds from inorganic and requiring at least the simplest organic substrates that enter the body with food.

And, probably, there is no need for such thoughts to come to mind during lunch or dinner. Eating, above all, is an aesthetic act. As I. P. Pavlov said, “you need to eat so that food gives you pleasure,” and therefore it is hardly advisable to imagine while eating what and how your favorite dumplings or cod turn into tomato sauce. However, you need to be smart in this matter. For what? Let us, dear reader, ask you a question: do you know how to eat?

What a miracle, another will say. What's so complicated about that? Take a spoon or fork, sometimes a knife, and act so that there is nothing left on the plate! No, it's not that simple. Don't believe me? Then answer the following questions:

1. How many calories does a person need per day?
2. How much protein, fat, carbohydrates, salts should a person consume per day?
3. How long should you chew food?
4. When should you leave the table?
5. How many times a day should you eat?
6. How many hours before bedtime should you take your last meal?
7. What should be the principles of menu design?

The list of questions can be continued. Well, dear reader, if you don’t answer even one question out of the seven above, you can assume that you don’t know how to eat and that your personal nutritional system, in addition to the fact that it allows you to introduce the necessary nutrients, every day causes some harm to your intestines, your heart, your blood vessels. Let this harm be small and unnoticeable every day. But small things add up to big things. That's why we decided to talk about digestion first, so that the reader can understand how we eat, and later we'll talk about how to eat correctly.

The digestion process begins long before the first piece of food enters the mouth.. The onset of digestion is associated with a specific, individual time for each person. In our body there are so-called “ The biological clock“: during the day, the rhythm of all life processes changes cyclically, the number of blood cells periodically decreases and increases, its coagulability changes, the activity of the digestive glands also changes - at certain hours they are activated, and at other times their activity is inhibited. This means that at a certain time (when these glands are activated) a person begins to experience a feeling of hunger.

Besides internal mechanism associated with biorhythms, there is another, which is based on a person’s individual habits - in those hours when he usually has breakfast, lunch or dinner, based on individual experience, his digestive glands begin to activate their activity. So, the digestion process begins with two “time” reflexes: an unconditional one, associated with hereditary biorhythms, and a conditional one, depending on the time of eating by a particular person.

Then comes the period of action of other stimuli: the person finds himself in the familiar environment of a dining room, restaurant, or sits down at the dinner table at home. A conditioned reflex to the situation arises, which further activates the digestive apparatus. But this reflex, like the previous ones (for a while), produces, so to speak, a nonspecific activation of the digestive apparatus: the digestive glands, primarily the stomach glands, begin to secrete juice, but its composition will be the same in all cases. After this, specific reflexes are activated: a person sees food, smells it, and when food enters the mouth, taste buds are irritated - nerve endings, embedded in the language. Here the “irritation” will be specific, and the digestive glands will begin to secrete juice, varying in quantity and composition, depending on the type of food that a person takes: a large amount of gastric juice rich in enzymes will be released for meat, a smaller amount with less content will be released for milk enzymes. If you eat crackers, a large amount of saliva is released, containing enough high concentration amylase enzyme, which breaks down carbohydrates. And if something sour gets into your mouth (for example, you chewed a slice of lemon), then saliva literally begins to flow like a fountain, but it contains almost no enzymes, but is rich in mineral salts that are involved in neutralizing citric acid.

Under the influence of all these factors in a short time First of all, the gastric glands rearrange their activity - the first phase of gastric secretion begins, which is called complex reflex, since a whole complex of reflexes, both unconditioned and conditioned, takes part in its formation.

When food enters the stomach, the second phase of gastric secretion will begin - neurochemical, which is associated with the direct action of the food bolus on the walls of the stomach, on its glands, on the nerve endings embedded in this wall.

This phase is called nervous because the reflex component continues to play a role in it, and chemical because chemical substances food directly affects the stomach wall.

Before the food reaches the stomach, another important initial stage of the digestion process takes place - chewing food. The food is crushed and due to this, in the future it will be more exposed to the digestive juices of the stomach. The chemical processing of food begins in the oral cavity. Saliva contains an enzyme that breaks down carbohydrates - ptyalin, or amylase.

This enzyme breaks down starch - a polysaccharide - into smaller components - dextrans. Try this experiment: take a small piece of bread and chew it for a long time. You will feel that the bread takes on a sweetish taste as starch has broken down into sugary substances. We usually don't chew food for several minutes and therefore carbohydrates are oral cavity are only partially split. In addition, saliva contains a mucous substance - mucin. It envelops and, as it were, “lubricates” food particles, facilitating their movement along the digestive canal.

In the stomach cavity, the digestion of proteins contained in food begins under the influence of the enzyme pepsin and hydrochloric acid. The glands of the stomach secrete the inactive proenzyme pepsinogen, which is activated under the influence of hydrochloric acid, also produced by the glands of the gastric wall. Hydrochloric acid, in addition to activating pepsin, also performs a number of other important functions: it causes the swelling of some proteins, preparing them for their breakdown by pepsin, creates the acidic reaction of the environment necessary for the action of pepsin, and also has a bactericidal (that is, killing microbes) effect.

The production of pepsin and hydrochloric acid by the glands of the stomach wall begins even before food enters the stomach. If the first complex-reflex phase of gastric secretion is well expressed, then the food enters the stomach, which is ready for digestion, and the breakdown of nutrients is active. The amount of hydrochloric acid and pepsin secreted by the stomach depends on the nature of the food entering the digestive tract: in one case, the environment will be very acidic and contain a lot of pepsin, and in the other, slightly acidic, pepsin-poor gastric juice is released. Pepsin has enormous digestive capacity: one gram of pepsin can digest approximately 50 kg of egg albumin in two hours, and gastric juice contains about one gram of pepsin per liter. It is very important that gastric juice is secreted in the exact quantity with the nature and quantity of food entering the stomach, otherwise it may adversely affect the gastric wall. It is not without reason that the occurrence of gastric ulcer is often preceded by gastritis: inflammation of the gastric wall during high acidity and the rich content of pepsin in gastric juice.

In order to imagine how much the dynamics of digestion in the stomach depends on the nature of the food taken, we, at the risk of somewhat overloading our story with factual material, will give a fairly large quote from the same 24th volume of the BME, since it very accurately and concisely gives an idea of this issue. “When taking mixed food, the quantity and quality of gastric juice varies depending on the percentage of the main types of food included in it, as well as various additional substances added to a particular dish. It has been established that when taking various soups greatest number juice is separated into barley, oatmeal and potato soups and relatively less into rice and semolina.

A significant amount of juice is released when eating pickle soup and cabbage soup, especially sour ones. Of the second courses, the largest amount of juice is separated on fish soufflé and the smallest on rice pudding and semolina porridge. From meat dishes the largest amount of juice is separated when taken meatloaf and the smallest - pasta.

A large amount of juice is released when eating stewed meat and especially beef stroganoff.

Among sweet dishes, the greatest secretion is caused by compote of dried fruits mixed with the juice of raw oranges. It should be added to the above quote that depending on the nature of the food, the duration of secretion and its latent period, that is, the time that passes between food intake and the onset of secretion. Thus, gastric secretion largely depends on what and how we eat.

From the stomach, the food bolus enters the duodenum, where digestion occurs under the influence of juices secreted from the so-called Brunner's glands of its wall, the secretion of the pancreas, liver and small intestine. Highest value in duodenal digestion (duodenum- Latin name duodenum) belongs to pancreatic juice (pancreas - the Latin name of the pancreas), which is secreted in quantities from 600 ml to 2000 ml per day and contains enzymes that break down proteins, fats, and carbohydrates. These include protein digesters trypsin, chemotrypsin and carboxypeptidase; saccharolytic enzymes - amylase, maltase and lactase - and lipase.

The mechanism for including these enzymes in the digestive process is very complex. Many of them are released in an inactive state and must be activated.

The digestive power of these enzymes depends not only on their quantity, but also on the reaction of the environment in the duodenum, on how acidic the stomach contents were.

The action of enzymes that break down proteins in the duodenum also depends on how intensively the primary breakdown of proteins in the stomach took place.

Duodenal digestion is also associated with the rate of entry of the food bolus from the stomach, and this, in turn, is due to the acidity of gastric juice. Without going into details that are not necessary in popular scientific literature, we only want to emphasize that the level of duodenal digestion is closely related to digestion in the stomach and is determined by the same factors.

Speaking about digestion in the duodenum, it must be emphasized that a very important enzyme in pancreatic juice is lipase, an enzyme that breaks down fats. Enzymes that break down proteins and carbohydrates are found in many parts of the digestive tract, and pancreatic lipase is practically the only lipolytic enzyme. Therefore, if the excretory function (that is, the production of digestive enzymes) of the pancreas is disrupted, it is fat metabolism that is significantly disrupted.

Bile from the liver also enters the duodenum. Bile emulsifies fats and activates lipase, that is, it promotes the breakdown of fats. Both the secretion of pancreatic juice and the secretion of bile, as well as the secretion of gastric juice, go through two phases - complex reflex and neurochemical and are subject to the same laws as in the stomach.

Final splitting food products occurs in the small intestine, where food masses are processed under the influence of pancreatic juice, with which they are soaked in the duodenum, and enzymes produced by the glands of the wall of the small intestine. In the small intestine, mainly the absorption of broken down foods occurs (partially it begins in the stomach, where a small amount of water and, if taken, alcohol) are absorbed, which enter the blood. Together with the blood flow, nutrients enter the liver, the main chemical laboratory of the body, where they are further processed; Some of them are carried through the bloodstream throughout the body and enter the cells, others are deposited in the liver or are used for the synthesis of other substances, in particular proteins. In the liver, toxic products for the body are neutralized during the breakdown of nutrients.

In the large intestine, into which the small intestine passes, intensive absorption of water occurs. The bolus of food is broken down less intensively here, since the juice of the large intestine is poor in enzymes. Of great importance for chemical processes in the large intestines is normal intestinal microflora. Undigested food remains are expelled from the body in the form of feces. It must be emphasized that in the large intestine, relatively small quantities Products that are toxic to the body are formed, which, when absorbed, enter the liver and are neutralized there. Gases (ammonia, carbon dioxide, hydrogen, hydrogen sulfide). Gases, formed mostly during the final breakdown of proteins, are needed to stimulate the motility of the large intestine and push feces to the rectum.

This, in a nutshell, is the process of digestion in the human body..

Human Digestion

In the stomach, food is mixed with gastric juice, which is a solution of hydrochloric acid and a mixture of pepsin enzymes. Their main function is the initial breakdown of protein molecules into amino acids. Next, the food bolus enters the small intestine, which consists of the duodenum, jejunum and. In the duodenum there are excretory ducts pancreas and gall bladder, through which bile and enzymes enter the intestinal lumen.

Pancreatic enzymes (lipase, amylase, trypsin, chymotrypsin and others) break down proteins into amino acids, fats into fatty acids, and complex carbohydrates– to simple ones. The pancreas also secretes hormones - insulin and glucagon, which coordinate carbohydrate metabolism. Bile contains bile acids, cholesterol and phospholipids. The main one is the breakdown and digestion of fats received from food. The small intestine itself also secretes its own enzymes. These are various peptidases that continue the process of protein breakdown; sucrase, maltase, for the breakdown of carbohydrates; and lipase – for the breakdown of fats.

Thus, in the small intestine, all nutrients that pass through are absorbed difficult path breakdown (proteins, fats, carbohydrates, vitamins and minerals). The small intestine is the main organ in which food is digested. The intestinal wall consists of microscopic villi, which are the “gates” between the intestinal lumen and blood capillaries. Through them, nutrients enter directly into the blood.

Further digestion takes place in the large intestine under the influence of “good” bacteria that inhabit its lumen. Absorption of water and electrolytes occurs in the colon. Undigested food particles move to the rectum using peristalsis and are excreted from the body.

Food is complex process, as a result of which they enter, digest and absorb necessary for the body substances. Over the past ten years, a special science devoted to nutrition—nutritionology—has been actively developing. In this article we will look at the process of digestion in the human body, how long it lasts and how to manage without a gallbladder.

The structure of the digestive system

It is represented by a set of organs that ensure the absorption of nutrients by the body, which are a source of energy for it, necessary for cell renewal and growth.

The digestive system consists of: the mouth, pharynx, small intestine, colon and rectum.

Digestion in the human oral cavity

The process of digestion in the mouth involves grinding food. In this process, energetic processing of food with saliva occurs, interaction between microorganisms and enzymes. After treatment with saliva, some of the substances dissolve and their taste appears. The physiological process of digestion in the oral cavity involves the breakdown of starch into sugars by the amylase enzyme contained in saliva.

Let's trace the action of amylase using an example: while chewing bread for a minute, you can feel sweet taste. The breakdown of proteins and fats does not occur in the mouth. On average, the digestion process in the human body takes approximately 15-20 seconds.

Digestive department - stomach

The stomach is the most wide part digestive tract, which has the ability to increase in size and accommodates great amount food. As a result of the rhythmic contraction of the muscles of its walls, the process of digestion in the human body begins with thorough mixing of food with gastric juice, which has an acidic environment.

Once a lump of food enters the stomach, it remains there for 3-5 hours, during which time it is subjected to mechanical and chemical treatment. Digestion in the stomach begins with exposure of food to gastric juice and the hydrochloric acid that is present in it, as well as pepsin.

As a result of digestion in the human stomach, proteins are digested with the help of enzymes into low molecular weight peptides and amino acids. The digestion of carbohydrates, which begins in the mouth, stops in the stomach, which is explained by the loss of amylases’ activity in an acidic environment.

Digestion in the stomach cavity

The process of digestion in the human body occurs under the influence of gastric juice containing lipase, which is capable of breaking down fats. Wherein great importance is given to hydrochloric acid of gastric juice. Under the influence of hydrochloric acid, the activity of enzymes increases, denaturation and swelling of proteins is caused, and a bactericidal effect is exerted.

The physiology of digestion in the stomach is that food enriched with carbohydrates, which remains in the stomach for about two hours, undergoes an evacuation process faster than food containing proteins or fats, which lingers in the stomach for 8-10 hours.

Food that is mixed with gastric juice and partially digested, being in a liquid or semi-liquid consistency, passes into the small intestine at simultaneous intervals in small portions. In which department does the digestion process still take place in the human body?

Digestive department - small intestine

Digestion in the small intestine, into which the bolus of food enters from the stomach, has the most important place, from the point of view of the biochemistry of the absorption of substances.

In this department intestinal juice comprises alkaline environment due to the arrival of bile, pancreatic juice and secretions of the intestinal walls into the small intestine. The digestive process in the small intestine does not go quickly for everyone. This is facilitated by the presence of an insufficient amount of the lactase enzyme, which hydrolyzes milk sugar, which is associated with the indigestibility of whole milk. During the digestion process, more than 20 enzymes are consumed in this part of the human body, for example, peptidases, nucleases, amylase, lactase, sucrose, etc.

The activity of this process in the small intestine depends on the three parts passing into each other, of which it consists - duodenum, jejunum and ileum. Bile formed in the liver enters the duodenum. Here food is digested thanks to the pancreatic juice and bile that act on it. This colorless liquid contains enzymes that promote the breakdown of proteins and polypeptides: trypsin, chymotrypsin, elastase, carboxypeptidase and aminopeptidase.

Role of the liver

An important role in the process of digestion in the human body (we will briefly mention this) is played by the liver, in which bile is formed. The peculiarity of the digestive process in the small intestine is due to the assistance of bile in emulsifying fats, absorbing triglycerides, activating lipase, also helps stimulate peristalsis, inactivate pepsin in the duodenum, has a bactericidal and bacteriostatic effect, increases hydrolysis and absorption of proteins and carbohydrates.

Bile does not contain digestive enzymes, but is important in the dissolution and absorption of fats and fat-soluble vitamins. If bile is not produced enough or is secreted into the intestines, then the processes of digestion and absorption of fats are disrupted, as well as an increase in their excretion in their original form with feces.

What happens in the absence of a gallbladder?

The person is left without the so-called small sac, in which bile was previously deposited “in reserve.”

Bile is needed in the duodenum only if there is food in it. And this is not a constant process, only during the period after eating. After some time, the duodenum is emptied. Accordingly, the need for bile disappears.

However, the work of the liver does not stop there; it continues to produce bile. It is for this purpose that nature created the gallbladder, so that the bile secreted in the intervals between meals does not deteriorate and is stored until the need for it arises.

And here the question arises about the absence of this “bile storage”. As it turns out, a person can do without a gallbladder. If the operation is performed on time and other diseases associated with the digestive organs are not provoked, then the absence of a gallbladder in the body is easily tolerated. The timing of the digestion process in the human body is of interest to many.

After surgery, bile can only be stored in bile ducts. After bile is produced by liver cells, it is released into the ducts, from where it is easily and continuously sent to the duodenum. Moreover, this does not depend on whether the food is taken or not. It follows that after the gallbladder has been removed, food must be taken frequently and in small portions for the first time. This is explained by the fact that there is not enough bile to process large portions of bile. After all, there is no longer a place for its accumulation, but it enters the intestine continuously, albeit in small quantities.

It often takes time for the body to learn to function without a gallbladder and to find the necessary place to store bile. This is how the digestion process works in the human body without a gallbladder.

Digestive department - large intestine

Leftovers undigested food move into the large intestine and remain in it for approximately 10 to 15 hours. Here the following digestive processes take place in the intestines: absorption of water and microbial metabolization of nutrients.

In the digestion that occurs in the large intestine, food plays a huge role, which includes indigestible biochemical components: fiber, hemicellulose, lignin, gums, resins, waxes.

The structure of food affects the speed of absorption in the small intestine and the time of movement through the gastrointestinal tract.

Part dietary fiber, which are not broken down by enzymes belonging to the gastrointestinal tract, are destroyed by microflora.

The large intestine is the place of formation of feces, which includes: undigested food debris, mucus, dead cells of the mucous membrane and microbes that continuously multiply in the intestines and which cause the processes of fermentation and gas formation. How long does the digestion process in the human body last? This is a common question.

Breakdown and absorption of substances

The absorption process occurs throughout the entire digestive tract, which is covered with hairs. On 1 square millimeter of mucous membrane there are about 30-40 villi.

In order for the process of absorption of substances that dissolve in fats, or rather fat-soluble vitamins, to occur, fats and bile must be present in the intestines.

Absorption of water-soluble products such as amino acids, monosaccharides, mineral ions occurs with the participation of blood capillaries.

U healthy person The entire digestion process takes from 24 to 36 hours.

This is how long the digestion process in the human body lasts.