The most common diseases of the gastrointestinal tract - symptoms, treatment, prevention. Anatomy of the stomach

In order to support all life processes, a person needs energy. We take it from food. In order for food to turn into energy and give the body all the necessary substances, there is a gastrointestinal tract. Here the primary processing, digestion of food and utilization of its residues take place. Needless to say, any diseases of the gastrointestinal tract can greatly ruin a person's life. It includes many organs and components, and therefore any violation can seriously affect the digestive processes and seriously harm health. It is on the correctness and efficiency of the digestive processes that the supply of other organs and systems with the necessary substances depends, so diseases of the gastrointestinal tract can result in a variety of problems. In order to understand what kind of problems may arise, it is necessary to understand how the digestive system is arranged, what components it consists of, and what disorders at what stage can cause diseases of the gastrointestinal tract.

Gastrointestinal tract: organs and structure

The gastrointestinal tract consists of several sections. Here, food undergoes complete processing, saturating the body with useful substances. The first stage of digestion begins in the mouth. Here the food is subjected to primary mechanical processing. The teeth, tongue, and salivary glands all work together to prepare food for the stomach by grinding and moistening it. This stage is very important, during it you can not rush. Popular wisdom says that you need to chew each piece 32 times - according to the number of teeth. There is a rational grain in this, because the more thoroughly the food is crushed, the less the load on the digestive tract. From the oral cavity, food enters the esophagus, which is an intermediate stage between the mouth and stomach. The main digestive process begins in the stomach. While the food in the mouth was being prepared, the stomach had already produced gastric juice and all the necessary enzymes for its digestion. While contracting, the walls of the stomach grind and grind food, and here begins the primary absorption and assimilation of useful substances. An empty stomach is approximately 0.5 liters in volume, but it can stretch significantly, increasing in size up to 8 times! The next stage of the digestive tract is the movement of digested food into the small intestine. The small intestine has 3 sections: the duodenum, the jejunum, and the ileum. All sections of the small intestine are covered with tiny villi, which increase the area of ​​​​absorption of nutrients. This makes it the main absorptive organ of the digestive tract. Numerous studies confirm that if part of the small intestine is removed, the body begins to experience a serious deficiency of nutrients. The large intestine terminates the gastrointestinal tract. It includes the caecum, colon, and rectum. In the large intestine, the absorption of useful components is completed, excess fluid is absorbed, and feces are formed. They are expelled through the rectum.

The gastrointestinal tract could not perform its functions without auxiliary organs. Salivary glands, pancreas, liver - without them, the process of digestion is impossible to carry out. And the actions of all organs are controlled by the brain, endocrine and immune systems. As you can see, the process of digestion is incredibly complex, many organs are involved in it. Each stage is important and necessary, so any violation will affect the state of the whole organism as a whole.

Diseases of the gastrointestinal tract

Many diseases of the gastrointestinal tract are caused by malfunctions of the immune system, which cannot cope with the number of harmful factors that it encounters daily. And if a person has a genetic predisposition, multiplied by malnutrition, tobacco and alcohol abuse, then gastrointestinal diseases will not take long. Consider the most common diseases of the digestive system.

Stomatitis is a disease that affects the mucous membrane of the mouth. It can be very uncomfortable. As a result, the ability to chew food well is reduced, which ultimately adversely affects the functioning of the stomach. The cause of stomatitis is a weak immune system.

Esophagitis occurs when the lining of the esophagus becomes inflamed. This can be caused by drinking alcohol, too rough, poorly chewed food, burns. Diseases of the gastrointestinal tract, such as esophagitis, cause quite severe pain and discomfort. There may be a burning sensation, vomiting, sometimes even with an admixture of blood.

A huge number of people suffer from heartburn. This condition is associated with an increase in the acidity of gastric juice. When part of it rises into the esophagus, there is a burning sensation.

Chronic gastritis is the most common gastrointestinal disease. Previously, it was believed that gastritis is a disease of students and people with a frantic pace of life who eat irregularly and incorrectly. Today, it is absolutely known that the vast majority of gastritis is caused by the bacterium Helicobacter pylori. Helicobacter pylori infection is one of the most common in the world and eloquently speaks of how deplorable the state of the immune system in most people. Chronic gastritis is an inflammation of the stomach lining. In fact, this is a disease that can have very serious consequences. First, the absorption of various beneficial substances is disrupted, for example, vitamin B12. Deficiency of this vitamin leads to the development of anemia. If gastritis is not treated, then its atrophic form may develop, which is considered a precancerous condition.

Chronic duodenitis and chronic colitis are inflammations of the mucous membranes of the duodenum and large intestine, respectively.

These are not all diseases of the gastrointestinal tract. There are many more of them, among them there are very dangerous ones, such as peptic ulcer or pancreatitis. Of course, the ideal option is prevention, which will help prevent gastrointestinal diseases. But what to do if the diseases are already diagnosed?

Treatment of gastrointestinal diseases and Transfer factor

As we have already said, the vast majority of diseases, including gastrointestinal diseases, cause disturbances in the immune system. Hostile single-celled organisms, autoimmune processes, infections - all this occurs if immune cells stop working as they are prescribed. Today, doctors and patients have at their disposal a unique drug that effectively treats gastrointestinal diseases and many other ailments. Immunomodulator Transfer factor is a concentrate of compounds - long chains of amino acids, which in the body of all mammals perform one function - the accumulation and transmission of information from mother to her children. Receiving this information, immune cells train, learn and begin to clearly understand how they must act in order for the body to be healthy and protected. If you are concerned about any diseases of the gastrointestinal tract, take Transfer Factor as an independent remedy or during complex therapy for the best results of treatment.

The human stomach is the body's main food storage reservoir. If the body did not have such a capacity as the stomach, we would eat constantly, and not just several times a day. It also releases a mixture of acid, mucus, and digestive enzymes that help digest and sanitize our food while it's being stored.

Macroscopic anatomy

What is a human stomach? It is a round, hollow organ. Where is the human stomach? It is located below the diaphragm on the left side of the abdomen.

The structure of human organs is such that the stomach is located between the esophagus and the duodenum.

The stomach is an enlarged crescent-shaped tract. Its inner layer is full of wrinkles, known to us as wrinkles (or folds). It is these folds that allow it to stretch to fit large portions of food, which subsequently moves quietly in the process of digestion.

Based on form and function, the human stomach can be divided into four parts:

1. The esophagus connects to the stomach at a small area called the cardia. This is a narrow, tube-like part that passes into a wider cavity - the body of the stomach. The cardia is made up of the lower esophageal sphincter, as well as a group of muscle tissue that contracts to keep food and acid in the stomach.

2. The cardial section passes into the body of the stomach, which forms the central and largest part of it.

3. Slightly above the body is a domed area known as its floor.

4. Below the body is the pylorus. This part connects the stomach to the duodenum and contains the pyloric sphincter, which controls the flow of partially digested food (chyme) from the stomach and into the duodenum.

Microscopic anatomy of the stomach

Microscopic analysis of the structure of the stomach shows that it is made up of several distinct layers of tissue: mucosal, submucosal, muscular, and serous.

mucous membrane

The inner layer of the stomach consists entirely of a simple epithelial tissue with many exocrine cells. Small pores called gastric pits contain many exocrine cells that produce digestive enzymes and Mucous cells located throughout the mucosa and gastric pits secrete mucus to protect the stomach from its own digestive secretions. Due to the depth of the gastric pits, the mucous membrane can thicken, which cannot be said about the mucous membrane of other organs of the gastrointestinal tract.

In the depths of the mucous membrane there is a thin layer of smooth muscles - the muscular plate. It is she who forms the folds and increases the contact of the mucosa with the contents of the stomach.

Around the mucous membrane there is another layer - the submucosa. It is made up of connective tissue, blood vessels and nerves. Connective tissues support the structure of the mucosa and connect it to the muscle layer. The blood supply of the submucosa ensures the supply of nutrients to the walls of the stomach. Nervous tissue in the submucosa controls the contents of the stomach and governs smooth muscle and the secretion of digestive substances.

muscle layer

The muscular layer of the stomach surrounds the submucosa and makes up most of the mass of the stomach. The muscular lamina consists of 3 layers of smooth muscle tissue. These layers of smooth muscle allow the stomach to contract to mix food and move it through the digestive tract.

Serous membrane

The outer layer of the stomach, surrounding the muscle tissue, is called the serosa, which is made up of simple squamous epithelial and loose connective tissues. The serosa has a smooth, slippery surface and secretes a thin, watery secretion known as the serosa. The smooth, wet surface of the serosa helps protect the stomach from friction during its constant expansion and contraction.

The anatomy of the human stomach is now more or less clear. Everything that is described above, we will consider a little later on the diagrams. But first, let's figure out what are the functions of the human stomach.

Storage

In the oral cavity, we chew and moisten solid food until it becomes a homogeneous mass, shaped like a small ball. As we swallow each pellet, it slowly passes through the esophagus to the stomach, where it is stored along with the rest of the food.

The volume of a person's stomach can vary, but on average it is able to hold 1-2 liters of food and liquid to aid digestion. When the stomach is stretched with a lot of food, it can store up to 3-4 liters. A distended stomach makes digestion difficult. Since the cavity cannot easily contract to mix the food properly, this results in a feeling of discomfort. The volume of a person's stomach also depends on the age and condition of the body.

After the stomach cavity has been filled with food, it remains for another 1-2 hours. At this time, the stomach continues the digestive process that began in the mouth and allows the intestines, pancreas, gallbladder and liver to prepare to finish the process.

At the end of the stomach, the pyloric sphincter controls the movement of food into the intestines. As a general rule, it usually closes to keep food and stomach secretions out. Once the chyme is ready to leave the stomach, the pyloric sphincter opens to allow a small amount of digested food to pass into the duodenum. Within 1-2 hours, this process is slowly repeated until all the digested food leaves the stomach. The slow release rate of chyme helps break it down and maximize digestion and absorption of nutrients in the gut.

Secretion

The stomach produces and stores several important substances to manage the digestion of food. Each of them is produced by exocrine or endocrine cells located in the mucous membrane.

The main exocrine product of the stomach is gastric juice - a mixture of mucus, hydrochloric acid and digestive enzymes. Gastric juices mix with food in the stomach to aid digestion.

Specialized exocrine mucosal cells - mucous cells that store mucus in the folds and pits of the stomach. This mucus spreads across the mucosal surface to coat the lining of the abdomen with a thick, acid- and enzyme-resistant barrier. Gastric mucus is also rich in bicarbonate ions, which neutralize the pH of stomach acid.

Located in the pits of the stomach, they produce 2 important substances: the internal factor of Castle and hydrochloric acid. Intrinsic factor is a glycoprotein that binds to vitamin B12 in the stomach and helps it be absorbed by the small intestine. is an essential nutrient for the formation of red blood cells.

The acid in the human stomach protects our body by killing pathogenic bacteria that are present in food. It also helps digest proteins, turning them into an unfolded form that is easier for enzymes to process. Pepsin is an enzyme that is activated only by hydrochloric acid in the stomach.

Chief cells, also found in the pits of the stomach, produce two digestive enzymes: pepsinogen and gastric lipase. Pepsinogen is the precursor molecule to a very powerful protein-digesting enzyme, pepsin. Since pepsin would destroy the master cells that make it, it has been hidden in the form of pepsinogen where it is harmless. When pepsinogen comes into contact with the acidic pH found in stomach acid, it changes shape and becomes the active enzyme pepsin, which converts proteins into amino acids.

Gastric lipase is an enzyme that digests fats by removing the fatty acid from the triglyceride molecule.

G-cells of the stomach - endocrine cells located at the base of the pits of the stomach. G cells synthesize the hormone gastrin into the bloodstream in response to many stimuli, such as signals from the vagus nerve, the presence of amino acids in the stomach from digested proteins, or the stretching of the stomach walls while eating. Gastrin passes through the blood to various receptor cells throughout the stomach, and its main task is to stimulate the gland and muscles of the stomach. The effect of gastrin on the glands leads to an increase in the secretion of gastric juice, which improves digestion. Stimulation of smooth muscle by gastrin promotes stronger contractions of the stomach and the opening of the pyloric sphincter to move food into the duodenum. Gastrin can also stimulate cells in the pancreas and gallbladder, where it increases the secretion of juice and bile.

As you can see, human stomach enzymes perform very important functions in digestion.

Digestion

Digestion in the stomach can be divided into two classes: mechanical and chemical digestion. Mechanical digestion is nothing more than the physical division of a mass of food into smaller portions, and chemical digestion is the transformation of larger molecules into smaller molecules.

Mechanical digestion occurs due to the mixing action of the walls of the stomach. Its smooth muscles contract, due to which portions of food are mixed with gastric juice, which leads to the formation of a thick liquid - chyme.

While food is physically mixed with gastric juice, the enzymes present in it chemically break down large molecules into their smaller subunits. Gastric lipase breaks down triglyceride fats into fatty acids and diglycerides. Pepsin breaks down proteins into smaller amino acids. The chemical decomposition, begun in the stomach, is not completed until the chyme enters the intestines.

But the functions of the human stomach are not limited to digestion.

Hormones

The activity of the stomach is controlled by a number of hormones that regulate the production of stomach acid and the release of food into the duodenum.

Gastrin, produced by the G-cells of the stomach itself, increases its activity by stimulating an increase in the amount of gastric juice produced, muscle contraction and emptying of the stomach through the pyloric sphincter.

Cholecystokinin (CCK) is produced by the lining of the duodenum. It is a hormone that slows down gastric emptying by contracting the pyloric sphincter. CCK is released in response to eating foods rich in proteins and fats, which are very difficult for our body to digest. CCK allows food to be stored in the stomach longer for more thorough digestion and gives time for the pancreas and gallbladder to release enzymes and bile to improve digestion in the duodenum.

Secretin, another hormone produced by the duodenal mucosa, responds to the acidity of the chyme entering the intestine from the stomach. Secretin passes through the blood to the stomach, where it slows down the production of gastric juice by the exocrine mucosal glands. Secretin also stimulates the production of pancreatic juice and bile, which contain acid-neutralizing bicarbonate ions. The purpose of secretin is to protect the intestines from the harmful effects of chyme acid.

Human stomach: structure

Formally, we have already familiarized ourselves with the anatomy and functions of the human stomach. With the help of illustrations, let's look at where the human stomach is located and what it consists of.

Picture 1:

This figure shows the human stomach, the structure of which can be considered in more detail. Here are marked:

1 - esophagus; 2 - lower esophageal sphincter; 3 - cardia; 4- body of the stomach; 5 - bottom of the stomach; 6 - serous membrane; 7 - longitudinal layer; 8 - circular layer; 9 - oblique layer; 10 - large curvature; 11 - folds of the mucous membrane; 12 - cavity of the pylorus; 13 - channel of the pylorus of the stomach; 14 - sphincter of the pylorus; 15 - duodenum; 16 - gatekeeper; 17 - small curvature.

Figure 2:

This image clearly shows the anatomy of the stomach. The numbers are marked:

1 - esophagus; 2 - the bottom of the stomach; 3 - the body of the stomach; 4 - large curvature; 5 - cavity; 6 - gatekeeper; 7 - duodenum; 8 - small curvature; 9 - cardia; 10 - gastroesophageal connection.

Figure 3:

Shown here is the anatomy of the stomach and the location of its lymph nodes. The numbers correspond to:

1 - upper group of lymph nodes; 2 - pancreatic group of nodes; 3 - pyloric group; 4 - the lower group of pyloric nodes.

Figure 4:

This image shows the structure of the stomach wall. Marked here:

1 - serous membrane; 2 - longitudinal muscle layer; 3 - circular muscle layer; 4 - mucous membrane; 5 - longitudinal muscle layer of the mucous membrane; 6 - circular muscle layer of the mucous membrane; 7 - glandular epithelium of the mucous membrane; 8 - blood vessels; 9 - gastric gland.

Figure 5:

Of course, the structure of human organs in the last figure is not visible, but the approximate position of the stomach in the body can be considered.

This image is quite interesting. It does not depict the anatomy of the human stomach or anything like that, although some parts of it can still be seen. This picture shows what heartburn is and what happens with it.

1 - esophagus; 2 - lower esophageal sphincter; 3 - contractions of the stomach; 4 - gastric acid, together with its contents, rises into the esophagus; 5 - burning sensation in the chest and throat.

In principle, the picture clearly shows what happens with heartburn and no additional explanation is required.

The human stomach, the pictures of which were presented above, is a very important organ in our body. You can live without it, but this life is unlikely to replace a full one. Fortunately, in our time, many problems can be avoided simply by periodically visiting a gastroenterologist. Timely diagnosis of the disease will help to get rid of it faster. The main thing is not to delay going to the doctor, and if something hurts, then you should immediately contact a specialist with this problem.

The student of anatomy uses, among others, two terms that seem to be synonymous. They are really extremely close, but still different from each other. "Digestive system" and "Gastrointestinal tract". The first concept includes the entire set of organs associated with digestion: the oral cavity, salivary glands, pharynx, esophagus, stomach, intestines, liver, gallbladder and pancreas, the second - only part of the digestive system, uniting the esophagus, stomach and the entire intestine.

Digestive system (PS) divided into two parts by a diaphragm, above which are the oral cavity with salivary glands, pharynx and most of the esophagus. Almost all other organs are located in the abdominal cavity, except for the final section of the large intestine, which enters the pelvic cavity.

Gastrointestinal tract (GIT) is a system of hollow organs interconnected by tubes, narrow or wide, straight or twisted. But, no matter how outwardly dissimilar these tubes may be, they have a fundamentally similar plan of the histological structure of the walls in all departments. It is in our interests to understand this general scheme, and in considering individual bodies, only to clarify some details or deviations from the rule.

If you start from the inside, that is, from the cavity of the “tube” itself (Fig. 1), then the first innermost layer will be mucous membrane. In the intestine, the mucosal surface increases due to the villi (2). Under the mucous understand the epithelial layer with the basement membrane. In the lower sections of the gastrointestinal tract, a thin layer of connective tissue directly under the basement membrane, and bundles of smooth myocytes (respectively, the own and muscular plates of the mucous membrane) are added to them. There are accumulations of lymphoid tissue on the mucosa in the intestine (5). The epithelium in most departments is cylindrical; the exception is the oral cavity, pharynx, esophagus and rectum in its middle part, where the epithelium is stratified squamous non-keratinizing. In the caudal part of the rectum, the keratinization of the epithelium even begins. The value of the mucous membrane is to provide protection from mechanical and chemical factors, participation in the breakdown of nutrients (parietal digestion) and absorption.

Fig.1. Diagram of the structure of the digestive tube

Slightly deeper in the wall submucosal layer(6) loose connective tissue, which contains arterial and venous plexuses, nerve networks (7), accumulations of lymph nodes. Here are the end sections (12) of complex alveolar-tubular glands (13), which produce mucus; excretory streams penetrate the mucous membrane and open into the lumen of the "tube". The severity of this layer is not the same in different departments, for example, in the esophagus it is quite thick, and in the large intestine it is less pronounced. Due to the large number of elastic fibers, the submucosal layer pulls the mucous membrane into folds (3), which are especially clearly visible in the esophagus, stomach and small intestine. We can say that where there are folds, there is a submucosal layer. Its meaning is as follows. Firstly, the submucosal layer is the receptacle of the glandular and lymphoid apparatuses that provide endocrine secretion and immune protection. Secondly, it is in the vascular and lymphatic networks of this layer that the substances absorbed by the mucous membrane enter. Finally, thirdly, it “softens” the passage of the food bolus and what this bolus then turns into through the gastrointestinal tract, significantly reducing the risk of injury.

The next is the muscle layer. As a rule, the fibers of smooth myocytes lie in two layers. Deeper, that is, directly behind the submucosa, there is a circular (or circular) layer (8), and more superficially - longitudinal (10) They also contain nerve plexuses (9). Typically, the thickness of both layers is on average the same. But there are places with a distinct predominance of circular fibers over longitudinal ones. Such areas are called pulps. But this word - pulp - is unlikely to be understood, since it is almost never used. A circular muscle that compresses a hollow organ or closes a hole is called a sphincter by both anatomists and doctors (from Greek, sphingo - to tightly tighten, squeeze). The muscular membrane may have nuances in different parts of the gastrointestinal tract (somewhere the longitudinal layer will almost disappear, somewhere the third layer will be added, somewhere not smooth muscles, but striated), but its function is the same everywhere: mixing and holding the contents of the tube.

The outer shell can be presented in two versions. In the abdominal cavity, the organs of the gastrointestinal tract are almost completely wrapped in the peritoneum, which will form a serous membrane (11) for them. In some places it passes into the mesentery (1). Supradiaphragmatic and located in the small pelvis organs are lined outside with loose connective tissue. Then they say that the outer shell is represented by adventitia. The participation of both species in the mechanical and partly in the antibacterial protection of organs from the outside is quite obvious.

The cavities of each department open one into the other, so sometimes the gastrointestinal tract is called the digestive canal. But in addition to the hollow organs of the gastrointestinal tract, the digestive system also includes parenchymal organs. This is primarily the liver and organs with glandular parenchyma: salivary and pancreas. The hollow gallbladder, although it has a fundamental similarity in its histological structure with the organs of the gastrointestinal tract, is not included in the digestive canal.

Without going into details, we will mention that during embryonic development, the oral cavity, pharynx and lower half of the rectum are formed from the ectoderm, and the entire gastrointestinal tract from the endoderm. This is what explains the difference in the structure of the mucous membranes of the organs of the first and second groups. The nervous system controls the work of the gastrointestinal tract with its autonomic department according to the general principle: the parasympathetic increases the secretory and motor activity of the organs, and the sympathetic reduces it.

The main function of the entire system is digestion, that is, the whole group of processes of splitting complex nutrients into simple components, assimilation of the latter and excretion of metabolic products and "slags" from the body.

The human digestive system performs complex work. It sometimes has nothing to do with the processing and assimilation of food. One of the components is the gastrointestinal tract (GIT). It can be thought of as the path that food takes after eating. The structure of the gastrointestinal tract largely determines the tendency of the body to a certain pathology.

A disease is not always an organic (anatomical) disorder. Dysfunction of different parts of the human intestinal tract plays an important role in the occurrence of diseases. To find out the cause of the disease, it is necessary to take into account the anatomical and physiological features and connections of organs, the role of the nervous and hormonal systems in managing the digestive process.

What is the digestive system for?

The digestive system performs the following main functions:

• motor - crushing, mixing and moving food masses along the tract, removing toxins from the body;
• secretory - the synthesis of enzymes for processing the food bolus to substances that allow them to be absorbed through the intestinal wall;
• absorption - of all the substances formed as a result of splitting, only those useful to the body are selected, water is absorbed.

Scientists have proven another equally important value of the digestive tract - the production of antibodies for local immunity and active biological substances involved in the systemic protection of a person. The gastrointestinal tract, as an important part of the structure of the digestive system, is involved in each of these processes. It is impossible to determine what is more important in the body than the liver, pancreas or intestines. Because changes in any part entail a malfunction of all components of the gastrointestinal tract.

What specialists study the work of the tract?

The structure of the human gastrointestinal tract is studied by the science "Human Anatomy". Histology (studies the structure of tissues under a microscope), cytology (the main subject is the structure of the cell), physiology (reveals the mechanisms of work and functional relationships of organs) and others “budded” from it.

The emergence and course of pathological processes belongs to the field of pathology and pathophysiology. It was these previously unknown scientific disciplines that served as the basis for all clinical medical specialties, became the founders of many research areas in medicine.

What is the GI tract and how does it work?

The gastrointestinal tract can be represented schematically as a "tube" that starts in the mouth and ends at the anus. In this structure there are departments of the gastrointestinal tract, each of which is responsible for certain tasks. To understand what disorders cause diseases, we will “walk along with food” along the tract and check which functions of the gastrointestinal tract are assigned to each department.

The better the food is chewed, the more accessible it will enter the stomach, saliva disinfects food, protecting the underlying parts of the system

Oral cavity

In the oral cavity, food is met by teeth, which crush it into small pieces, saliva (the secret of large and small glands), and the tongue. Saliva enzymes break down starchy substances in foods; as a liquid, it moistens and makes it easier to swallow. Prolonged chewing can deceive the center of hunger and cause a feeling of fullness, therefore it is recommended for obese patients to combat excess weight.

Lack of teeth in old age, prosthetic problems greatly complicate the process. In a hurry, a person swallows pieces of food unprepared for digestion, which threatens a functional failure of the next stage in the stomach. The receptors of the tongue determine and transmit information about the amount and composition of enzymes that will be required for digestion.

Esophagus

In fact, it ensures the delivery of food mass to the stomach due to longitudinal and transverse contractions of the muscle layer. The further process is localized below the diaphragm, in the abdominal cavity. Violation of the act of swallowing with anomalies of the structure or inflammation (achalasia, esophagitis) leads to a delay and stagnation of the lump. The delay in the entry of food into the stomach is reflected in the activity of the glands of its inner shell.

The stomach has an elastic folded structure, which allows it to expand significantly. If necessary, the body can hold up to 4 liters of liquid and food. Not all products are processed equally quickly: glucose, alcohol, salts, water are the first to be absorbed into the blood. Acts on food residue. The active substances in it are mucus, hydrochloric acid, enzymes (pepsin, gastrin).

Juice production is carried out by parietal cells located between the epithelial cells. It is produced by the type of food, the smell. The maximum spending falls on the processing of meat and spicy dishes. Changes in the form of atrophy disrupt the functioning of the organ.

Acidity decreases as one approaches the passage to the duodenum

The muscles of the stomach mix the mass to increase the area of ​​contact with the enzymes.

The duodenum is the initial part of the human intestinal tract. Its task is to obtain food mass from the pylorus, convert the acid reaction into an alkaline one (more suitable for the intestines) and continue the breakdown of proteins and carbohydrates. From the duodenum, minerals, vitamins, and excess fluid are absorbed into the blood.

At this stage, the synthesized secret of the pancreas and bile are connected to digestion by attaching ducts through the common sphincter of Oddi.

Bile is produced by hepatocytes (liver cells), is collected in the bladder, contains, in addition to water, fatty acids, cholesterol and inorganic substances.

The composition allows you to emulsify the fatty components of food, break them down to amino acids, fatty acids, vitamins, and prevents the processes of decay. Pancreatic juice enters through the pancreatic duct, containing more than 20 enzymes that act on all food components. The final process of digestion occurs in the loops of the small and large intestines.

Scheme of the confluence of the pancreatic and bile ducts into the intestine

Intestines

The length of the small intestine is up to 6 m. In addition to the duodenum, it includes the jejunum and ileum. The wall must ensure the absorption of the necessary substances into the blood vessels. To do this, it is covered from the inside with folds and tiny villi. Large molecules do not pass through a dense shell.

About 200 types of bacteria live in the intestines. The maximum amount is made up of useful bifidobacteria and lactobacilli. The remaining opportunistic pathogens are normally included in 1-2% of the structure. Maintaining the correct composition of the intestinal flora is very important for digestion. It is these smallest microorganisms, together with intestinal juice, that provide the breakdown of food residues into molecules to be absorbed (amino acids, polysaccharides, fatty acids).

The imbalance of microflora is sensitive to the effects of various factors, of which special attention is paid to medicinal substances (antibiotics). Therefore, after treatment of the gastrointestinal tract with antibacterial agents, it is necessary to restore the necessary ratio of bacteria.

All substances from the intestine do not enter the general circulation, but into the portal vein of the liver. The fact is that in the form in which they are presented in the intestines, chemicals can cause death, because they form poisons, toxins. The liver decontaminates poisons to non-toxic compounds. The ileum "transfers" food debris to the large intestine.

It has a length of up to 2 m, anatomically divided into the caecum with the appendicular process, ascending, transverse colon, descending, sigmoid, straight. The task of this department is the formation of fecal masses, the completion of water absorption, the release of all accumulated toxins from the body. The cells secrete mucus. Living bacteria help to destroy an alien infection, maintain immunity.

The cleansing function of the intestines depends on the work of the muscles. Their peristaltic movements allow transporting feces to the area of ​​the anal sphincters and are responsible for the act of defecation. Contractions depend on interaction with the branches of the parasympathetic nervous system, sufficient production of the mediator acetylcholine.

A serious problem of postoperative and senile disorders. Stagnation of toxins causes intoxication of the body, allergic mood. The listed important departments are interconnected by a single process of digestion. Pathological changes in one of the levels leads to dysfunction of the entire gastrointestinal tract.

Through the mesenteric vessels, blood is collected in the portal system of the liver.

What does "functional disease" mean?

The sections of the gastrointestinal tract do not work in isolation “on their own”. They are connected by control from the nervous system and endocrine organs that secrete hormones. In addition, substances synthesized by the cells of the stomach (gastrin, secretin), pancreas have hormonal activity. In the oral cavity there are nerve fiber endings that transmit information about the quantity and quality of food received to the center.

Therefore, according to the reverse signals, the stomach and intestines are prepared in advance. For example, an “order is formed” for the amount of bile and pancreatic juice needed for digestion in the duodenum. The contractile function that pushes the food bolus to the next level is regulated by innervation, most often the vagus and sympathetic nerves are involved. They "take care" of sufficient strength of the wave of peristalsis, alternate or simultaneous contraction of the longitudinal and circular muscles.

An important role belongs to the proper functioning of the sphincters. These are muscle sphincter located on the border of the esophagus and stomach, stomach and duodenum. Inside the duodenum, the sphincter of Oddi acts as a passageway. It lets pancreatic juice and bile from the supply ducts into the small intestine. At the transition to the caecum, the role of the valve is performed by the fold of the mucosa.

It only works if the bowel is at a certain angle to the end of the small intestine. Powerful sphincters of the sigmoid colon allow you to accumulate feces, bring them into the rectal ampulla for defecation. Functional diseases are called diseases that have arisen due to a mismatch of signal information and orders from the centers of the brain.

In connection with impaired contractile activity, stagnation of the contents in the stomach, esophagus, and intestines occurs. Or, conversely, excessive contractions remove undigested residues, do not allow the absorption of nutrients and vitamins. Such disorders are called dyskinesias. Failure of compression and relaxation of the sphincters causes spastic muscle contractions, expansion of the overlying part of the gastrointestinal tract, insufficient production of enzymes, stagnation with the risk of infection.

Diagnosis is made by a gastroenterologist

Most often, functional diseases occur under the influence of stressful situations, hard work, alternation of hungry intervals and overload of digestion, alcohol intake, narcotic substances. If measures are not taken at this stage, the pathology becomes organic, accompanied by anatomical changes in the structure of organs, and at the cellular level - gross deviations in composition and structure. An example is epithelial metaplasia - the transformation of stomach cells into intestinal cells in gastritis.

How does the anatomy of the human gastrointestinal tract change in diseases?

Anatomical disorders in vivo can be detected using modern diagnostic methods. The use of X-ray studies, ultrasound and endoscopic techniques made it possible to determine not only the type of changes, but also the stage of the process, the degree of damage.

X-ray diagnostics is based on the laws and norms of X-ray anatomy. The radiologist can determine the position and boundaries of the gastrointestinal tract by comparing with the human skeleton, large muscles. This part of the body is always well contrasted on the screen. Therefore, localization is considered in relation to the vertebrae, diaphragm, ribs.

For example, for the stomach, the projection of the upper point to the left of the vertebrae 0.5–2.5 cm below the dome of the diaphragm is considered normal, the pyloric section is in the zone of the first or second lumbar vertebrae, and the transition to the duodenum is also located here. In children, it lies higher. There are 9 segments in the esophagus. The picture is most indicative when contrasted with a barium solution.

It allows you to judge:

• about the lumen of the internal cavity (changes are found in tumors, diverticula);
• displacement relative to normal localization (gastroptosis, diaphragmatic hernia, compression by a tumor-like formation of neighboring organs);
• violation of the direction and number of folds (smoothing is likely for atrophic gastritis);
• changes in contours (symptom of "niche" in peptic ulcer disease).

X-ray sign of a filling defect is characteristic of a tumor, a polyp of the stomach

X-ray diagnostics uses images from different angles, examination of the patient in a vertical, horizontal, knee-elbow position. The air in the intestine interferes with the procedure, so the person needs to be prepared in advance (diet, cleansing enemas). To contrast the intestines, irrigoscopy is used - filling with barium through an enema, followed by a series of images.

Ultrasound is a technique based on the property of sound wave reflection from different tissues. Since the stomach and intestines are hollow organs, it is not used in diagnostics. Various endoscopic techniques (fibrogastroscopy, esophagogastroduodenoscopy, colonoscopy) allow you to visually examine suspicious areas of the gastrointestinal tract. The most modern devices display a picture on the monitor and make it possible to record the procedure, take pictures.

The method is indispensable in identifying the early stages of cancer, determining the form of inflammation, and finding the source of bleeding. In recent years, improvements have made it possible to carry out some surgical operations with the help of endoscopy, to take biomaterial for histological examination.

The anatomy of the gastrointestinal tract includes mandatory sections on blood supply and innervation. Surgeons need to know how the most important vessels and nerves pass in order to develop the correct operative technique and avoid complications during the operation. The work of the stomach and intestines is provided by glandular organs (liver, pancreas), gallbladder. Together they make up a complete digestive system.

The human digestive system occupies one of the places of honor in the arsenal of knowledge of a personal trainer, solely for the reason that in sports in general and in fitness in particular, almost any result depends on the diet. Gaining muscle mass, losing weight or maintaining it largely depends on what kind of "fuel" you load into the digestive system. The better the fuel, the better the result will be, but now the goal is to figure out exactly how this system is arranged and works and what are its functions.

The digestive system is designed to provide the body with nutrients and components and remove the residual products of digestion from it. The food entering the body is first crushed by the teeth in the oral cavity, then it enters the stomach through the esophagus, where it is digested, then, in the small intestine, under the influence of enzymes, the digestive products break down into separate components, and feces (residual digestion products) are formed in the large intestine. , which is ultimately subject to evacuation from the body.

The structure of the digestive system

The human digestive system includes the organs of the gastrointestinal tract, as well as auxiliary organs, such as the salivary glands, pancreas, gallbladder, liver, and more. The digestive system is conventionally divided into three sections. The anterior section, which includes the organs of the oral cavity, pharynx and esophagus. This department carries out food grinding, in other words, mechanical processing. The middle section includes the stomach, small and large intestines, pancreas and liver. Here chemical processing of food, absorption of nutrients and the formation of residual products of digestion take place. The posterior section includes the caudal part of the rectum and performs the removal of feces from the body.

The structure of the human digestive system: 1- Oral cavity; 2- Sky; 3- Tongue; 4- Language; 5- Teeth; 6- Salivary glands; 7- Sublingual gland; 8- Submandibular gland; 9- Parotid gland; 10- Throat; 11- Esophagus; 12- Liver; 13- Gallbladder; 14- Common bile duct; 15- Stomach; 16- Pancreas; 17- Pancreatic duct; 18- Small intestine; 19- Duodenum; 20- Jejunum; 21- Ileum; 22- Appendix; 23- Large intestine; 24- Transverse colon; 25- Ascending colon; 26- Blind gut; 27- Descending colon; 28- Sigmoid colon; 29- Rectum; 30- Anus.

Gastrointestinal tract

The average length of the alimentary canal in an adult is approximately 9-10 meters. The following sections are distinguished in it: the oral cavity (teeth, tongue, salivary glands), pharynx, esophagus, stomach, small and large intestine.

• Oral cavity An opening through which food enters the body. On the outside, it is surrounded by lips, and inside it are teeth, tongue and salivary glands. It is inside the oral cavity that food is crushed with teeth, wetting with saliva from the glands and pushing the tongue into the throat.
• Pharynx- digestive tube that connects the mouth and esophagus. Its length is approximately 10-12 cm. Inside the pharynx, the respiratory and digestive tracts cross, therefore, so that food does not enter the lungs during swallowing, the epiglottis blocks the entrance to the larynx.
• Esophagus- an element of the digestive tract, a muscular tube through which food from the pharynx enters the stomach. Its length is approximately 25-30 cm. Its function is to actively push the crushed food to the stomach, without any additional mixing or pushing.
• Stomach- a muscular organ located in the left hypochondrium. It acts as a reservoir for swallowed food, produces biologically active components, digests and absorbs food. The volume of the stomach ranges from 500 ml to 1 liter, and in some cases up to 4 liters.
• Small intestine The part of the digestive tract located between the stomach and large intestine. Enzymes are produced here, which, in conjunction with the enzymes of the pancreas and gallbladder, break down the products of digestion into separate components.
• Colon- the closing element of the digestive tract, in which water is absorbed and stool is formed. The walls of the intestine are lined with a mucous membrane to facilitate the passage of the residual products of digestion to the exit from the body.

The structure of the stomach: 1- Esophagus; 2- Cardiac sphincter; 3- Fundus of the stomach; 4- The body of the stomach; 5- Large curvature; 6- Folds of the mucous membrane; 7- Sphincter of the gatekeeper; 8- Duodenum.

Subsidiary Bodies

The process of digestion of food occurs with the participation of a number of enzymes that are contained in the juice of some large glands. In the oral cavity there are ducts of the salivary glands, which secrete saliva and moisten both the oral cavity and food with it to facilitate its passage through the esophagus. Also in the oral cavity, with the participation of saliva enzymes, the digestion of carbohydrates begins. Pancreatic juice and bile are secreted into the duodenum. Pancreatic juice contains bicarbonates and a number of enzymes such as trypsin, chymotrypsin, lipase, pancreatic amylase and more. Before entering the intestine, bile accumulates in the gallbladder, and bile enzymes allow the separation of fats into small fractions, which accelerates their breakdown by the lipase enzyme.

• Salivary glands divided into small and large. Small ones are located in the oral mucosa and are classified by location (buccal, labial, lingual, molar and palatine) or by the nature of the excretion products (serous, mucous, mixed). The size of the glands varies from 1 to 5 mm. The most numerous among them are the labial and palatine glands. There are three pairs of major salivary glands: parotid, submandibular, and sublingual.
• Pancreas- an organ of the digestive system that secretes pancreatic juice, which contains digestive enzymes necessary for the digestion of proteins, fats and carbohydrates. The main pancreatic substance of the ductal cells contains bicarbonate anions that can neutralize the acidity of the residual products of digestion. The islet apparatus of the pancreas also produces the hormones insulin, glucagon, and somatostatin.
• gallbladder acts as a reservoir for bile produced by the liver. It is located on the lower surface of the liver and anatomically is part of it. The accumulated bile is released into the small intestine to ensure the normal course of digestion. Since in the process of digestion bile is not needed all the time, but only periodically, the gallbladder doses its intake with the help of bile ducts and valves.
• Liver- one of the few unpaired organs in the human body, which performs many vital functions. Including she is involved in the processes of digestion. Provides the body's needs for glucose, transforms various energy sources (free fatty acids, amino acids, glycerol, lactic acid) into glucose. The liver also plays an important role in neutralizing toxins that enter the body with food.

The structure of the liver: 1- Right lobe of the liver; 2- Hepatic vein; 3- Aperture; 4- Left lobe of the liver; 5- Hepatic artery; 6- Portal vein; 7- Common bile duct; 8- Gallbladder. I- Path of blood to the heart; II- Path of blood from the heart; III- The path of blood from the intestines; IV- The path of bile to the intestines.

Functions of the digestive system

All functions of the human digestive system are divided into 4 categories:

• Mechanical. Involves grinding and pushing food;
• Secretory. Production of enzymes, digestive juices, saliva and bile;
• Suction. Assimilation of proteins, fats, carbohydrates, vitamins, minerals and water;
• Highlighting. Excretion from the body of the remnants of digestion products.

In the oral cavity, with the help of teeth, tongue and salivary gland secretion product, during chewing, the primary processing of food occurs, which consists in grinding, mixing and moistening with saliva. Further, in the process of swallowing, food in the form of a lump descends through the esophagus into the stomach, where it is further chemically and mechanically processed. In the stomach, food accumulates, mixes with gastric juice, which contains acid, enzymes and proteins that break down. Further, the food, already in the form of chyme (liquid contents of the stomach), in small portions enters the small intestine, where it continues to be chemically processed with the help of bile and excretory products of the pancreas and intestinal glands. Here, in the small intestine, nutrients are absorbed into the blood. Those food components that are not digested move further to the large intestine, where they are decomposed by bacteria. The large intestine also absorbs water and then forms feces from the residual products of digestion that have not been digested or absorbed. The latter are excreted from the body through the anus during defecation.

The structure of the pancreas: 1- Accessory duct of the pancreas; 2- Main pancreatic duct; 3- Tail of the pancreas; 4- Body of the pancreas; 5- Neck of the pancreas; 6- Uncinate process; 7- Vater papilla; 8- Small papilla; 9- Common bile duct.

Conclusion

The human digestive system is of exceptional importance in fitness and bodybuilding, but naturally it is not limited to them. Any intake of nutrients into the body, such as proteins, fats, carbohydrates, vitamins, minerals and more, occurs precisely through the intake through the digestive system. Achieving any results in terms of gaining muscle mass or losing weight also depends on the digestive system. Its structure allows us to understand which way food goes, what functions the digestive organs perform, what is absorbed and what is excreted from the body, and so on. Not only your athletic performance depends on the health of the digestive system, but, by and large, all health in general.