The structure of the gastrointestinal tract: anatomical features. Functions and structure of the stomach What is the structure of the stomach

>> what is the stomach?

(lat. ventriculus, gaster) is a hollow organ of the digestive tract, in which food is accumulated and partially digested.

Anatomical characteristics of the stomach
The entire gastrointestinal tract can be represented as a tube about 7-8 m long. The upper sections of the digestive tract are represented by the oral cavity, pharynx, esophagus, stomach and initial section small intestine(duodenum), the lower ones - a continuation of the small intestine (jejunum and ileum), as well as the large intestine with its terminal section - the rectum. As it passes through the various sections of this tube, food undergoes various changes - digestion and absorption. The stomach is a sac-like extension of the digestive tube located between the esophagus and the duodenum. Food from the mouth enters the stomach through the esophagus. From the stomach, partially digested food masses are excreted into duodenum(the beginning of the small intestine).

The site provides background information for informational purposes only. Diagnosis and treatment of diseases should be carried out under the supervision of a specialist. All drugs have contraindications. Expert advice is required!

The stomach is a hollow organ that is a reservoir for digesting food. It is located between the esophagus and the duodenum. After grinding in the oral cavity, food enters the stomach, where it accumulates and is partially digested under the action of gastric juice, which contains hydrochloric acid and some digestive enzymes. These enzymes contribute to the digestion of proteins and the partial breakdown of fats.

Gastric juice has a pronounced bactericidal effect. Due to this, it has a detrimental effect on many pathogens that can enter the stomach cavity along with poor-quality food. It is a well-known fact that people with high stomach acid almost never get cholera.

The gastric juice also contains a special mucous substance - mucin, which protects the walls of the stomach from self-digestion.

The structure of the stomach

The stomach is a muscular hollow organ appearance resembling the letter J. The length of its convex lower contour, called the greater curvature of the stomach, is three times greater than the concave upper contour (small curvature).

The stomach can be conditionally divided into three parts:

• Cardiac department - includes the junction of the esophagus and stomach (cardiac opening) and the fundus of the stomach;
• The body of the stomach is its middle part;
• The pylorus or pylorus is the junction of the stomach with the duodenum.

The stomach is made up of four layers. Inside there is a mucous membrane, the cells of which produce gastric juice and enzymes. Next to it is the submucosa. It is made up of fibers connective tissue, between which there are nerves, blood and lymphatic vessels. Next shell consists of smooth muscle fibers, and outside it is covered with a serous membrane.

The volume of an empty stomach is about half a liter. When filled with food, it can stretch up to four liters.

Stomach acidity

The total acidity of the stomach depends on the content of hydrochloric acid in the gastric juice produced by parietal cells present in the mucous membrane. The acidity of the stomach is also determined by the number of parietal cells and the alkaline components contained in the gastric juice, which neutralize the total acidity.

Diseases of the stomach

Among all diseases internal organs most often found various pathologies digestive organs, including stomach diseases: gastritis (acute and chronic), peptic ulcer, cancer. With all these diseases, there is such a symptom as pain in the stomach. These pains can be of the most diverse nature: aching, sharp, paroxysmal. Often, stomach pain is associated with eating. So, for example, with peptic ulcer pain in the stomach occurs after eating, and with ulcerative lesions of the duodenum, pain is characteristic that disappears after eating, the so-called "hungry" pains.

The stomach is treated by a gastroenterologist. To make the correct diagnosis in gastroenterology, various instrumental methods diagnostics: esophagoscopy, gastroduodenoscopy, ultrasound procedure, laparoscopy, etc. These methods are quite simple, safe and quite informative.

Modern gastroenterology has a large arsenal medications allowing to treat the stomach with conservative methods. TO surgical treatment resorted to only in cases where drug treatment does not lead to the desired effect, and also in the presence of malignant neoplasms stomach or massive bleeding.

Correct work digestive system for human health has great importance. It is the stomach that is its key organ. It contains muscle fibers. It is so elastic that it can increase in size up to 7 times. The sections of the stomach are necessary for the proper process of digestion of food. Everyone has certain responsibilities.

The hollow space in the digestive system resembles a sac. This is the stomach, serving as a junction above the esophagus and below the duodenum. It consists of several departments, performs numerous functions, contributes to the normal functioning of the body.

After the food enters the mouth, the person carefully chews it and swallows it. It goes down into the stomach. It accumulates there, partially digested under the influence of hydrochloric acid and special enzymes. They are essential for the breakdown of proteins and fats. The food then moves through the gastrointestinal tract.

Organ structure

The digestive system supports human life. The stomach occupies a special place in its structure. It contains muscle fibers, has high elastic qualities. It can stretch from the original volume several times. It starts from the esophagus and runs to the duodenum.

Sphincters are located in the lower and upper parts of the organ. We are talking about the cardinal and pyloric elements. The main process of digestion takes place in the stomach. Products entering there are partially broken down and continue to move to other organs located below.

According to anatomy, the stomach consists of two walls. There are front and rear interlocking surfaces. The edges of the organ form the greater and lesser curvature of the stomach. When a person eats food, he fills up. The greater curvature of the stomach in this situation is at the level of the navel.

On the inner covering of the organ is the mucous membrane. It is necessary for the formation of enzymes involved in the process of digestion. Under the mucous membrane there is a muscular layer. On the outside, a serous coating.

Functional Features

In the gastrointestinal tract, food accumulates, mixes, and partially breaks down. The stomach performs many other functional duties:

• saves food;
• controls basal secretion of gastric juice;
• conducts chemical processing of food;
• promotes the movement of food and timely emptying;
• absorbed through it into the blood nutrients;
• has a bactericidal effect;
• performs protective functions.

In the process of digestion, all metabolic products are removed. The same applies to substances that have a negative effect on the functioning of the endocrine glands.

Departments

The gastrointestinal tract consists of several parts. Each department performs a specific function and takes part in the process of digesting food.

Cardiac. The department is located next to the heart, for which it received its name. This is the border between the esophagus and the stomach, where the cardiac sphincter is located. It is made up of muscle fibers. The pulp prevents food from entering the esophagus.

Bottom of the stomach. A section that is located at the level of the esophagus. It looks like a dome. It is called the bottom (vault). In this part, air is collected, which enters the digestive organ along with food. The bottom mucosa contains a large number of glands that secrete hydrochloric acid. It is essential for the digestion of food.

Body. The main and most part of the digestive organ. Its beginning lies in the region of the cardiac region and ends in the pyloric part. The absorbed food collects in the body.

Pyloric department. The area, which is also called the gatekeeper. It is located below all departments. After the pyloric region, the small intestine begins. It includes a canal and a cave. These two sections also perform certain functions. The channel facilitates the movement of food from the stomach into the duodenum. The cave stores partially digested food.

All parts of the stomach support the proper functioning of the digestive system. Each area requires a certain amount of time to function. Fruit juices or broths are digested for 20 minutes. Meat dishes require 6 hours.

A plate for calculating the digestion time for certain types of products that you consume

The activity of the digestive system

The human stomach works under the influence of certain factors. External sources include the feeling of hunger, touch, sight, sensations. The internal factor is the process of digestion.

It all starts from the moment food enters the mouth. It mixes with saliva and is chewed. Swallowing movements contribute to its movement into the esophagus. Under the influence of the sphincter, it moves to the main digestive organ - the stomach.

There are several stages of food processing.

Diagram of the human digestive system

Storage. The walls of the digestive organ relax to stretch and accommodate more food.

Mixing. The lower part of the organ is compressed, which leads to mixing of its contents. Gastric enzyme, hydrochloric acid, breaks down proteins to help digest food. Additional cell wall supports the protective layer of the walls of the digestive organ by secreting a certain amount of mucus.

Emptying. After mixing, the food moves to the region of the upper small intestine. Here is the chemical process of splitting fats. It involves intestinal enzymes, pancreatic secretion.

Gastric juice has a detrimental effect on numerous pathogens due to its bactericidal properties. Sometimes pathogens of various diseases with low-quality products enter the digestive system. And also gastric juice contains mucin, a mucous substance that protects the walls of the digestive organ from self-digestion.

Prevention of violations

It is possible to prevent gastric pathologies. enough to support complex mechanism the process of digestion. Human life can be disrupted if the nutrients are no longer absorbed. Experts recommend remembering some helpful tips that support the proper digestive process:

• protect the stomach from injury;
• avoid drinking raw tap water;
• adhere to simple rules of hygiene, maintain a healthy state of the oral cavity;
• take walks in the fresh air every day;
• observe the regime of night rest;
• take medications strictly after consulting a doctor.

When talking about the prevention of digestive disorders, we should not forget about proper nutrition. Wholesome food keeps the body healthy. A person should adhere to a healthy, regular and varied diet. Such simple rules help maintain the health of the digestive system, prevent malfunctions and gastric pathologies.

It is important to monitor the condition of the stomach in order to timely seek help from specialists. Knowledge of its structure and functioning will help maintain healthy organ activity.

The digestive tract is one of the important parts in the human body. It processes food. It breaks down into small components - vitamins, trace elements, fiber and others. It also has beneficial microflora. It protects the body from the invasion of harmful bacteria and maintains normal metabolic processes. One of the organs abdominal cavity is the stomach. Where is it located, what is it responsible for and what is its device? Let's tell.

It does not depend on us how to arrange the digestive organs in the body. If we talk about the structure of the stomach, then it is quite complex. This is the first organ where food is processed under the influence of enzymes, gastric juice, hydrochloric acid and bile.

Under the stomach, it is customary to understand a hollow, elastic instrument that has a bag-like shape. It connects the esophagus and the intestinal canal. There is a collection, digestion, the transformation of food from a solid to a liquid state.

Allocate some parts of the stomach in the form:

• bottom and vault. Is in upper area abdomen
• cardial part of the stomach. It is so called because it is located near the heart. Represents the border between the esophagus and stomach. Consists of muscle structures called pulp. It is used to prevent food from passing from the stomach into the esophagus;
• body of the stomach. This part is considered the largest of all. It receives the food that the person has consumed. There she waits for further digestion. The body has an upper and lower curvature;
• pyloric or pyloric department. The gatekeeper is located below. This is where the stomach ends and the small intestine begins. The main function is to redirect the contents of the stomach into the duodenum.

Thus, you can learn about the complete structure of the gastric organ.

Functionality of the stomach

Anatomy is one of the branches of medicine that allows you to better learn about human structure. This group also includes the functions of the stomach.

This body allows:

• save food;
• regulate the basal secretion of gastric juice;
• treat products with chemicals;
• promote food and defecate in a timely manner;
• ensure the absorption of nutrients into the blood;
• have a bactericidal effect;
• show protective functions;
• remove metabolic products;
• to separate substances whose influence is aimed at enhancing the work of the secretory glands.

If the stomach starts to hurt, then one of the departments is affected. This adversely affects the functionality of the organ and the general condition of the person.

Location and shape of the stomach

Almost every patient knows where the stomach is. It is located in the upper part on the left, presumably behind the ribs. The empty hollow organ does not touch the peritoneum, but between them there is colon. But the exact form is difficult to describe, since all organisms are individual. A huge role in changing the structure is played by:

• the amount of incoming food coma;
• food regime;
• body position;
• physical condition of internal organs and muscle ligaments.

The stomach can look different. It is pear-shaped, retort-shaped, sickle-shaped, bag-shaped. The volume of an empty hollow organ is 500 milliliters. When it is filled, it increases to 1 liter. There are people who eat a lot. This also affects the volume of the stomach. Usually its walls are stretched. In such cases, the body can fit up to 3-4 liters of food.

If we talk about the structure of the children's stomach, then it will differ significantly from the adult. First of all, the question arises, where can the stomach be located? In newborns, the body has a relatively small size. It looks like a ball. It contains no more than 35 milliliters of breast milk or formula.

As the child grows, the stomach gradually stretches. Already by the year it acquires an oblong shape. To all this, its volume also increases. If it holds up to 350 milliliters of food per year, then by the age of seven, the amount increases by 2.5 times.

If we consider the gastric organ in section, then we can determine the thickness of the walls and the length of the sides. If a person is completely healthy, then the wall thickness will not exceed 5-6 millimeters. The length of the emptied hollow organ ranges from 18 to 20 centimeters. When filled, it rolls off up to 22-26 centimeters.

The structure of the walls of the stomach

The stomach is made up of several sections. But him anatomical structure turns out to be even more difficult.

The walls of the stomach are made up of several layers.

• Muscle fibres. They are needed so that the body can actively contract and promote the food bolus of food. They consist of an outer layer in the form of rectus muscles, a middle layer in the form of circular muscles, the inner layer in the form of oblique muscles. Muscle fibers are responsible for the shape of the organ.
• Serous layer. It is separated from the muscle fibers by a layer. Inside are located nerve endings. To all this, it provides nutrition to tissues. This layer covers the entire organ and gives it a certain shape. It is in it that the blood vessels are located.
• The mucous membrane of the stomach. Formed from folds. When they are straightened, the volume of the organ increases. Also there are gastric fields.

The layers of the stomach are complex. And each of them is responsible for certain functions.

The condition of the glands

When considering the lining of the stomach and its parts, it is worth learning about the glands. They play one of the important roles in the process of digestion. They are divided into two types. The first type of glands form chemical components. The second type helps to bring these compounds through the excretory tract.

The glands are located in different departments, each of which performs its own function.

1. Cardiac. Located at the entrance to the stomach. Their peculiarity lies in the softening of food and preparation for its digestion.
2. Own. There are several varieties. The main ones are necessary for the breakdown and digestion of protein and dairy compounds. The mucous glands produce mucus. The parietal glands produce hydrochloric acid.
3. Pyloric. Are near small intestine. Their action is aimed at secreting mucous cells, which form mucus. This substance helps prevent adverse effects and partially extinguish hydrochloric acid. Pyloric glands also dilute gastric juice.

Endocrine glands can also be attributed to this group. They affect the functioning of the stomach.

How the stomach works

The digestive process is one of the main activities. It connects two types of state in the form of internal and external. The first of them is responsible for digestion, the second - for the feeling of hunger, touch, vision.

As you know, the process of digestion begins with the oral cavity. Food is exposed to saliva and then chewed. With the help of swallowing movements, it enters the esophagus. The sphincter is triggered, the valve opens and the consumed products enter the stomach through the hole.

The recycling mechanism begins. It is divided into several stages.

1. Storage. The stomach walls relax and stretch. This process makes it possible to capture a large amount of food.
2. Mixing. The lower section begins to actively contract, which makes it possible for food to mix with gastric juice. It contains hydrochloric acid, enzymes, proteins, mucus.
3. Emptying. Porridge-like food passes into upper part small intestine. Under the action of enzymes intestinal tract and the pancreas, there are chemical processes for the breakdown of fats, proteins and carbohydrates.

Food can stay in the stomach for 1-2 hours. If a lot of food has been eaten, then some will remain undigested and simply get stuck between the esophagus and stomach. This process leads to the suspension of the work of the body. In order for it to start performing its functions again, you will have to perform special exercises, use folk methods or gastric lavage.

Common diseases of the stomach

The most common complaint of patients is pain on the left side in the region of the stomach. It does not matter what the organ will consist of. With any adverse effect, the front surface and the mucous membrane begin to suffer first. This process subsequently negatively affects the functions.

If you do not take care of your health, you can develop various diseases. The causes of pathologies can be anything. Most often, the stomach suffers from regular stressful situations, malnutrition and overeating.

This is one of the organs, arranged so that all the symptoms affect the external state of the body.

The main signs of damage to the stomach include:

• allergic reactions on the skin;
• blanching;
• plaque formation in the tongue;
• painful sensations of aching, dull or acute nature;
• belching with sour contents, heartburn;
• nausea and vomiting.

In medicine, a large list of diseases of the stomach is distinguished in the form of:

• ulcerative lesions of the stomach. It is characterized by deformation of the mucous membrane. Causes pathological process become a decrease in the protective function. The main signs of the disease include constant pain on the left side after eating;
• gastritis. This disease is commonly understood as an inflammatory process that occurs as a result of Helicobacter pylori entering the body. Gastritis manifests itself in painful sensations in the abdomen, nausea, dizziness, belching, heartburn and whitish coating on the tongue;
• prolapse of the stomach. The organ descends as a result of a weakening of muscle tone. The disease can be both congenital and acquired. The reasons may be rapid weight loss, weight lifting, childbirth. Omission adversely affects the functioning of the digestive tract and the promotion of the food bolus. There is a violation of the function of the valve, which is located between the stomach and esophagus;
• malignant formations. It is often detected in the last stages, since the disease practically does not manifest itself. The main symptoms include loss of appetite, depression, decreased performance. For the most part, the cardiac region is affected. If the tumor ruptures, peritonitis will set in.

There are other less dangerous diseases in the form of erosion, bulbitis, pneumatosis, disorder.

You can prevent their occurrence if you follow a few recommendations.

1. Avoid injury to the abdominal cavity.
2. Do not drink water from the tap.
3. Monitor the condition of the oral cavity.
4. Healthy food.
5. Maintain a sleep and rest schedule.
6. Take medications only after consulting a doctor.

The stomach has a complex structure. But, despite this, he is primarily exposed to an unfavorable environment. Therefore, you should be careful about your health.

The human body receives nutrients and vitamins through the process of digestion that occurs in the gastrointestinal tract. The stomach is one of the organs where food enters through the esophagus after preliminary processing (chewing) in the oral cavity.

The structure of the stomach of humans and animals can differ significantly, which is associated with the type of food consumed. But structural features can cause the development of certain diseases.

The stomach is a part of the digestive tube, a hollow organ in which food is digested under the action of gastric juice, stored for several hours. In an adult, its length is 24-26 cm, width 7-10 cm. Moreover, during fasting, its volume is less than 100 ml, and after eating it can reach 2-3 liters, with obesity up to 5 liters or more.

The main function of the stomach is the mechanical and chemical processing of food. In addition, it includes:

Gastric juice can damage the tissues of a living organism. Features of the anatomy of the structure and physiology of the stomach normally do not allow an aggressive environment to destroy its walls. But due to the influence of adverse factors, damage to the cells lining the stomach from the inside and the development of the disease is possible.

Location and anatomy

At healthy people The stomach is located in the upper part of the abdominal cavity, where the liver, spleen, pancreas, and retroperitoneal organs are also located. Therefore, with pain in this area, it is necessary to differentiate the defeat of the stomach from other diseases. Its localization during the digestion of food almost does not change, since on the one hand it is connected to the abdominal esophagus, on the other with the duodenum. There are also several ligaments that pass from it to neighboring organs:

• hepatic-gastric;
• gastro-diaphragmatic;
• gastro-splenic;
• gastrocolic.

When filled, the lower limit may drop to the level of 3-4 lumbar vertebrae. And with constant overeating, some connective tissue diseases, developmental anomalies, or with age, it can reach the entrance to the pelvis. This condition is called gastric prolapse and requires surgical correction.

In the photo you can see where the human stomach is located and what organs surround it. In front, a small triangular area is adjacent to abdominal wall, the rest to the left lobe of the liver. Behind are the pancreas and spleen, which also covers the stomach from above and to the left. From below, it comes into contact with the loops of the small intestine.

If you look at the stomach in the photo, you can see that its shape resembles an inverted bag, a horn tapering downwards. It consists of the anterior and posterior walls, covered with visceral peritoneum, except for the place of their connection - the greater and lesser curvature.

There are several departments;

They differ in histological structure, the qualitative composition of the glands.

Blood supply is carried out:

• right and left gastric arteries located along the lesser curvature;
• gastroepiploic artery, branches along the greater curvature;
• the branch of the splenic artery approaches the bottom and upper part of the greater curvature.

Next to the arteries and veins, in the thickness of the ligaments are the branches of the nerves that carry out innervation, the lymphatic vessels and lymph nodes.

How the stomach works

Food enters the stomach through the esophagus, where, under the action of gastric juice and hydrochloric acid, it is digested within 2-6 hours. Due to the periodic contraction of the muscles, which is called peristalsis, the food masses are mixed, turning into a liquid mushy mass, gradually move towards the exit and are pushed out into the duodenum in portions.

At the esophageal opening and the transition to the duodenum there are circular thickenings of the muscles that prevent food from entering the esophagus and regulate its gradual movement into the intestine.

When the esophageal valve fails, stomach contents back up into the esophagus, causing heartburn. And damage to the sphincter can cause bile, pancreatic juice to enter the stomach, or, conversely, the outflow of acidic contents into the intestine, which causes irritation and ulceration.

Stenosis in this area leads to a slowdown in the passage of food, an increase in the duration of its stay in the stomach. This causes stretching of the walls, activates the processes of decay.

The structure of the walls of the stomach

On the diagram of the structure of the walls of the human stomach, you can see that it consists of 3 layers:

Digestion of food occurs under the action of the secret secreted by the glands.

The condition of the glands

The secretory function of the stomach is provided by three types of glands that contain the following types of cells:

Regulation of the formation of gastric juice is also carried out vegetatively. nervous system. The number of glands is about 40 million. With atrophy of the inner lining of the stomach, their number decreases sharply.

Useful video

How the organ is arranged is described in this video.

Structural features that affect the development of diseases

The occurrence of diseases of the stomach is also influenced by hereditary predisposition, features of the constitution. So, the inflammatory process, ulcerative changes often occur in people with asthenic physique. Most likely, this is due to the shape of the stomach, which can be seen during x-ray examination.

In hypersthenics, the stomach is usually in the form of a horn, in normosthenics it looks like a hook, and in asthenics it is elongated and resembles a stocking. Although 80% of patients with peptic ulcer infection is detected Helicobacter pylori, connection inflammatory processes in the stomach with the constitution remains and is taken into account in the diagnosis and treatment of the disease.

Common diseases of the stomach

The most common diseases of the stomach are:

• gastritis, acute and chronic form;
• erosion;
• stomach ulcer;
• cancer.

In addition, there are dyspeptic disorders (heartburn, belching), developmental pathologies, deformities caused by cicatricial changes.

Disease prevention

Prevention of diseases of the stomach is based on the exclusion of factors that can damage its walls, disrupt the digestive process and the evacuation of food masses. Recommended:

1. Observe the diet. The mode allows the stomach to rest, since secretory activity increases by the time of eating, and digestion is faster and better.
2. Do not overeat, as a strong stretching of the walls disrupts motility, food lingers longer in the stomach.
3. Limit foods and dishes that have an irritating effect (spices, fried, fatty).
4. Refuse bad habits(alcohol, smoking). It is known that the protective properties of mucus are violated under the influence of alcohol, some medicines eg NSAIDs.
5. Increase overall immunity, play sports so that the body can resist Helicobacter pylori infection.

And if symptoms of stomach damage occur, you should immediately consult a doctor, undergo an examination, in particular, FGDS, in order to start treatment on time.