Medical statistics notes that in recent decades, pathologies of the gastrointestinal tract have taken a leading place in the list of diseases. Experts confirm that the majority of city dwellers suffer from eating disorders in one way or another.

The modern rhythm of life, full of constant stress, poor ecology, improper and irrational nutrition lead to the fact that by the age of 30 every fourth person has one of the diseases of the gastrointestinal tract in his anamnesis. Which of them are the most common, what is the cause of pathological conditions and how to deal with diseases of the digestive tract?

Everyone knows that a person cannot live without food, with it he receives the proteins, carbohydrates, fats, vitamins and microelements necessary for the life of the body. They are a source of energy and the main building material for new cells. And it helps to get this energy from the incoming products of the human gastrointestinal tract.

The digestive system itself consists of the following main sections: oral cavity, pharynx, esophagus, stomach. This is followed by the lower sections: small and large intestines, rectum. Each of these departments performs a specific function in the processing and assimilation of incoming food.

Under the influence of adverse factors, malfunctions in the gastrointestinal tract occur, leading to various diseases. What are the most common triggers for disease?

Causes of intestinal diseases

Diseases of the digestive system can provoke the following factors:

The list of adverse factors is quite extensive and the risk of developing a pathology of the digestive system is high for each person. Therefore, special attention should be paid to the slightest signs of trouble in order to avoid the development of serious and dangerous diseases. What symptoms should you look out for?

Symptoms of intestinal diseases

The main symptoms of intestinal diseases are known to many. But the nature of the manifestations in each case is individual, and the severity of the symptoms depends on the affected organ and the stage of the disease.

In addition to these main symptoms, there are a number of characteristic signs that indicate damage to the digestive system:

Most of these symptoms do not pose a great danger, but significantly reduce the patient's quality of life and affect his performance. If symptoms are ignored and medical help is sought late, diseases of the digestive system become chronic, and their exacerbation can have serious consequences for the patient.

All diseases of the digestive tract by nature of origin are divided into two large groups:

1. infectious
2. non-infectious

According to the localization of the pathological process, diseases of the following organs are distinguished:

• stomach
• Esophagus
• Intestine (small and large)
• biliary tract
• Liver

In addition, diseases of the gastrointestinal tract are acquired and hereditary, acute and chronic.

Acute intestinal diseases mainly have a bacterial-infectious nature and develop against the background of poisoning, allergic reactions, or some pathological conditions (viral hepatitis, esophagitis).

Chronic inflammatory processes, such as gastritis, colitis, cholecystitis, develop against the background of a long-term violation of the diet, the use of low-quality and harmful products. Moreover, such chronic diseases rarely occur in isolation, in most cases the entire digestive tract is involved in the inflammatory process. Let us consider in more detail the most common pathological conditions of the gastrointestinal tract.

A short list of the most common diseases of the gastrointestinal tract:

The list of diseases of the gastrointestinal tract is quite extensive and the above ailments are only a small part of them. The treatment of intestinal diseases requires a competent approach, correct and timely diagnosis and timely access to a doctor when unfavorable symptoms appear.

Diagnosis of diseases of the gastrointestinal tract

For the diagnosis of diseases of the digestive system, methods of physical and instrumental examination are used.

Physical examination

To begin with, the doctor will interview the patient, collect an anamnesis, ask about complaints, well-being, diet, heredity, and the presence of chronic diseases. Then he will proceed to examine the patient using diagnostic methods such as palpation, auscultation and percussion.

1. involves probing the internal organs through the abdominal cavity. The method is based on tactile sensations and allows you to examine the position of organs, their shape, consistency, mobility and pain with your fingers.
2. Auscultation- this is listening to the internal organs with a phonendoscope or stethoscope.
3. Percussion- a method that allows, by tapping on various parts of the body, to determine the physical condition and topography of internal organs.

Instrumental examination

The basis of many diseases of the gastrointestinal tract is a violation of the secretion and motor activity of various parts of the digestive tract. Therefore, methods for studying the acidity of gastric juice, such as intragastric, daily and endoscopic pH-metry, are in the first place.

To study the motility of the gastrointestinal tract, methods of manometry and gastrography are used. In order to visually inspect the inner surface of the esophagus, stomach and intestines, endoscopic methods are used.

If it is necessary to examine the internal organ as a whole in order to identify pathological defects, methods of fluoroscopy, laparoscopy, MRI are used. ( magnetic resonance imaging), CT (computed tomography) and ultrasound (ultrasound). In some cases, diagnostics are carried out using radioactive substances (scintigraphy).

In addition, laboratory diagnostic methods are used, histological examination of tissue samples taken by biopsy is carried out, cytological and microbiological studies are carried out.

Treatment of intestinal diseases

Therapy of intestinal diseases begins after a thorough examination and clarification of the diagnosis. The course of treatment will depend on the specific disease, the stage of its development, the general condition and well-being of the patient. In most cases, methods of conservative drug therapy are used. In some acute cases, there is a need for surgical intervention.

Therapist or gastroenterologist is engaged in the treatment of diseases of the gastrointestinal tract. If any adverse symptoms associated with the digestive organs occur, it is important to promptly seek medical help and establish a diagnosis. It is unacceptable to self-medicate and postpone a visit to the doctor, this can result in serious complications or conditions that threaten the patient's life.

The tactics of treatment in each case will be selected individually, based on the results of the examination. In combination with drug therapy, many people use folk remedies: decoctions and infusions of medicinal plants. They give a good therapeutic effect, but they can be used only after consultation with the attending physician and under his supervision.

Recently, there has been a significant increase in the number of diseases of the digestive system in children. Many factors contribute to this:

1. bad ecology,
2. unbalanced diet,
3. heredity.

Sweets and confectionery products with a high content of preservatives and artificial colors, fast food, carbonated drinks, so beloved by many, cause great harm to the child's body. The role of allergic reactions, neuropsychic factors, and neuroses is growing. Doctors note that intestinal diseases in children have two age peaks: at 5-6 years and at 9-11 years. The main pathological conditions are:

• , diarrhea
• Chronic and acute gastritis and gastroenteritis
• Chronic enterocolitis
• Peptic ulcer of the stomach and duodenum
• Chronic cholecystitis
• Chronic pancreatitis
• Diseases of the biliary tract
• Chronic and acute hepatitis

Of great importance in the occurrence and development of gastrointestinal diseases is the insufficient ability of the child's body to resist infections, since the child's immunity is still weak. The formation of immunity is greatly influenced by proper feeding in the first months of life.

The best option is breast milk, with which protective bodies are passed from mother to child, increasing the ability to resist various infections. Formula-fed babies are more susceptible to various diseases and have a weakened immune system. The cause of violations in the digestive system can be irregular feeding or overfeeding of the child, early introduction of complementary foods, non-compliance with hygiene standards.

A separate group consists of acute intestinal diseases in children (dysentery, salmonellosis). Their main clinical manifestations are dyspeptic disorders, dehydration (dehydration) of the body and symptoms of intoxication. Such manifestations are very dangerous and require immediate hospitalization of a sick child.

Intestinal infections are especially often diagnosed in childhood, this is due to the imperfection of protective mechanisms, the physiological characteristics of the digestive organs and the lack of sanitary and hygienic skills in children. Especially negative acute intestinal infections affect young children and can lead to a significant decrease in immunity, delayed physical development, and complications.

Their onset is accompanied by characteristic signs: a sharp increase in temperature, abdominal pain, diarrhea, vomiting, loss of appetite. The child becomes restless, or, on the contrary, lethargic and inhibited. The clinical picture largely depends on which parts of the intestine are affected. In any case, the child needs emergency medical care and antibiotic therapy.

The treatment of diseases of the digestive system in babies is handled by a pediatric gastroenterologist, it is he who should be contacted when unfavorable symptoms appear.

Diet and eating habits in diseases of the gastrointestinal tract

Diseases of the gastrointestinal tract are so different that it is impossible to give any specific recommendations that are suitable for all patients without exception. Adjustment of the diet in each case is made by the doctor individually, taking into account all the characteristics of the patient and his diagnosis. We can only consider the principles of a healthy diet, which must be observed by all patients suffering from pathologies of the digestive system.

Diet for intestinal diseases involves fractional nutrition, in small portions, this allows you not to overload the stomach and prevent overeating. You need to eat 5-6 times a day, preferably at the same time. Be sure to observe the drinking regimen. On the day the patient should drink 1.5-2 liters of liquid and in the form of water, juices, compotes, weak tea (preferably herbal or green). Carbonated drinks are excluded.

Food should be as sparing as possible, not irritating the mucous membrane of the stomach and intestines. It is preferable to use:

• porridge cooked in water
• low-fat meat and fish broths,
• omelets,
• puree,
• souffle.

It is better to cook meat in the form of cutlets, meatballs, dumplings. All products are best boiled, baked or steamed; fried foods should be discarded. Observe the temperature regime when serving ready meals. Do not eat too hot or cold food. Meals should be served warm.

Vegetables are best cooked or mashed, fruits can be grated or baked (baked apples). Vegetables with coarse fiber, which cause fermentation processes in the stomach and excessive gas formation, are not recommended. These are cabbage, all kinds of legumes, radishes, corn, radishes, turnips.

It is necessary to limit or minimize the use of flour and confectionery products, sweets, strong coffee, tea, and avoid fast food. It is strictly forbidden to drink alcohol, fatty, fried, salty, spicy, pickled foods. It is better to exclude from the diet:

• condiments,
• sauces,
• semi-finished products,
• canned food and all other products containing artificial colors and preservatives.

Food should be fresh, easy to digest and contribute to the normalization of the digestive tract. The less refined food in the diet, and more foods containing fiber and dietary fiber, the better the digestive system will work.

Prevention

Prevention of intestinal diseases primarily includes measures to ensure a balanced and healthy diet. Observe personal hygiene and sanitary requirements when preparing meals. This way you protect yourself from foodborne infections.

Eat more fruits and vegetables, choose the right methods of thermal processing of food (boiling, stewing). Eat fractionally, do not overeat, give up snacks on the go and fast food. Nutrition should be balanced and varied, with the right ratio of nutrients (proteins, fats, carbohydrates, vitamins).

Try to move more, lead an active lifestyle, go in for sports, walk more, do feasible physical exercises, run, swim.

Fight stress and psychological tension, for this you can take natural sedatives (motherwort, valerian).

If you experience any adverse symptoms associated with the work of the digestive tract, seek medical help in a timely manner, do not self-medicate. This is the only way to avoid the transition of the disease to the chronic stage and achieve recovery.

The gastrointestinal tract includes organs that carry out the mechanical and chemical processing of food, the absorption of water and nutrients into the blood or lymph, and the removal of undigested residues from the body.

Symptoms of diseases associated with the gastrointestinal tract

Esophagus

The esophagus is a muscular tube 22-30 cm long, which is located between the pharynx and stomach. The esophagus is covered with a mucous membrane, under which there are glands that moisten food as it passes into the stomach. Promotion of food occurs due to wave-like contractions of the walls of the esophagus.

Stomach

The stomach is an organ of the gastrointestinal tract that is capable of stretching and is located between the esophagus and the duodenum. The stomach is connected to the esophagus by the cardia, and to the duodenum by the pylorus. Inside the stomach is covered with a mucous membrane, the glands of which produce enzymes, hydrochloric acid and mucus.

In the stomach, food is mixed and digested under the influence of gastric juice, which contains the enzyme pepsin and hydrochloric acid. These substances turn food into chyme, a partially digested semi-liquid mass, which then enters the duodenum.

Small intestine

The length of the small intestine reaches 4.5 m. It occupies most of the abdominal cavity, located in the form of loops, and is divided into the duodenum, jejunum and ileum. It is in the small intestine that most of the digestion and absorption takes place. The first section of the small intestine - the duodenum starts from the pylorus and reaches the jejunum. It receives bile from the gallbladder and juice from the pancreas.

In the walls of the duodenum there are glands that secrete an alkaline secret, which protects the duodenum from the acidic chyme that enters it from the stomach. The second section of the small intestine - the jejunum is about two-fifths of its length and connects the duodenum and ileum. The movement of digested food in the small intestine occurs due to transverse and longitudinal contractions of the muscles of its walls.

Colon

From the small intestine, food enters the large intestine, the length of which is 1.5 m. The large intestine begins with the caecum, from which a process leaves - the appendix. Intestine - The main part of the large intestine - the colon consists of four sections: ascending, transverse, descending and sigmoid. The large intestine absorbs water, electrolytes and fiber. At the end of the large intestine is the rectum, where undigested food collects. The rectum starts from the sigmoid colon and ends with the anus, through which feces are excreted from the body.

The lifestyle of a modern person often leads to the development of many diseases. In particular, low physical activity, improper and irregular nutrition, unfavorable ecological environment negatively affect the body, which eventually becomes difficult to maintain its normal mode of operation.

This disease manifests itself in the form of an inflammatory process covering the mucous membrane of the organ. In most cases, gastritis manifests itself in a chronic form. Often, gastritis causes the development of other gastric diseases. In the case of gastritis, the patient may complain of the following symptoms:

• feeling of heaviness in the stomach
• vomit
• nausea
• pain in the stomach

It is important to remember that many pathologies of the stomach, occurring in remission, have practically no signs of manifestation. Nevertheless, destructive processes continue in the organ even when there are no symptoms of this.

Gastritis

Symptoms of gastrointestinal disease - a lot!

In the case of gastritis, against the background of low acidity of the organ, various formations are formed on the lining of the stomach - tumors and polyps. Food is not digested sufficiently, the digestion process deteriorates, the patient may suffer from anemia.

When sick. proceeding with increased acidity, hydrochloric acid corrodes the walls of the organ, erosion and ulcers form. In especially severe cases, perforation of the stomach is possible - the formation of a hole, as a result of which the contents of the organ flow into the abdominal cavity.

Ulcer

Behind gastritis, in the list of diseases of the stomach, are ulcers and erosions, also called peptic ulcers. They are damage that occurs on the mucous membrane of the organ, or else. The difference between an ulcer and erosion is in the degree of tissue damage. In the case of erosion, shallow damage to the mucosa occurs, which does not affect the underlying tissues.

The main sign of the occurrence of ulcers is acute pain that haunts the patient both when his stomach is empty and some time after it is filled with food. Peptic ulcers are characterized by seasonal exacerbations.

functional indigestion

Pathology of an organ, not accompanied by changes in the integrity of its shell. This disorder includes an abnormal change in the acidity of gastric juice, dyspepsia, various functions, hypotension, and vomiting. In case of functional diseases, the following symptoms appear:

• belching
• general weakness
• irritability
• temperature increase (in case of poisoning)

Most pathologies of the gastrointestinal tract have similar symptoms. In order to accurately determine the disease, it is necessary to consult a gastroenterologist. This must be done in a timely manner, immediately after the slightest suspicion of the occurrence of pathology.

Intestinal diseases and their symptoms

Improper nutrition is the main cause of diseases of the digestive tract

The basis of a variety of bowel diseases is inflammation, which can be acute, chronic or infectious. In the process of development of the inflammatory phenomenon, not only one section of the intestine, but several at once, can be affected. Depending on the localization of inflammation, the disease has a specific name:

• enteritis
• sigmoiditis
• proctitis
• colitis
• typhlitis

As a result of inflammation, the mucous membrane of the affected intestine becomes hyperemic, edematous, discharge of a different nature can be produced: hemorrhagic, serous or purulent. In especially severe cases, frequently bleeding ulcers develop. If the development of the ulcer is not stopped, it eventually causes perforation of the affected area and the subsequent development of peritonitis. Intestinal pathologies negatively affect its functions:

1. digestion worsens
2. stops the absorption of nutrients
3. intestinal peristalsis worsens
4. there is an increase

The main signs of the occurrence of pathologies are:

• diarrhea
• constipation
• intestinal bleeding
• loss of appetite

Depending on the localization of the disease in the intestine, it has a specific name. In general, the symptoms of all diseases are similar and the main one is the occurrence of pain.

Symptoms of gastrointestinal diseases

Since almost all diseases of the gastrointestinal tract have fairly similar symptoms, it is necessary to consider each of them in more detail.

Nausea

Human intestine - schematic

This symptom can be defined as an unpleasant sensation, which is accompanied by increased salivation, general weakness, low pressure and is localized in the epigastric region. In the case of diseases of the gastrointestinal tract, this symptom is a reflex, which indicates irritation of the receptors in the stomach or biliary tract.

There are many reasons for this unpleasant symptom. It often accompanies diseases such as gastritis, ulcers, tumor disease, pancreatitis,.

Vomit

The process by which the contents of the stomach are expelled through the mouth. If vomiting is caused as a result of pathologies of the gastrointestinal tract, then its occurrence is associated with the same reasons as the previous symptom. Frequent vomiting threatens the risk of dehydration and the occurrence of electrolyte imbalance in the body.

Belching

The process by which gases are released from the stomach through the mouth. Aerophagia - swallowing air while eating can also cause belching. This symptom may indicate a deterioration in the functioning of the upper sections of the stomach and other diseases.

Bitterness in the mouth

Symptoms of hepatic dyspepsia. Appears as a result of impaired motility of the gallbladder and excretory duct, stomach, duodenum. This symptom most often occurs with cholecystitis and. It is also possible its appearance in peptic ulcers of the organs.

Pain in the abdomen

Pain as a symptom of gastrointestinal disease

This symptom may indicate the development of any disease of the gastrointestinal tract. If the cause lies in the hollow organs - the stomach or intestines, then the occurrence of pain indicates a spasm of smooth muscles, or stretching of the walls of the organ.

This is usually observed in case of blood flow disorders, as well as in the presence of inflammation. When pathology affects a non-hollow organ - pancreas, etc., then the appearance of pain indicates an abnormal increase in the size of this organ.

Diarrhea

Frequent bowel movements, during which there is an increase in the volume of feces, as well as their liquefaction. The occurrence of diarrhea is associated with the rapid movement of food through the digestive tract, as a result of which the food does not have time to undergo normal processing, and the liquid is not absorbed normally. The most common cause is intestinal inflammation caused by viruses or bacteria.

In addition, the cause of diarrhea may be a digestive disorder, which is observed with pancreatitis or cholestasis. In some cases, diarrhea is a side effect of certain medications.

Constipation

A bowel condition that makes it difficult to empty. The feces become harder, the patient suffers from pain and flatulence. As a rule, constipation indicates a deterioration in the motility of the large intestine. Also, constipation can be caused. There are many types of constipation, each of which occurs with a particular disease.

Digestive system- This is a human organ system, consisting of the digestive or gastrointestinal tract (GIT), liver and pancreas, designed to process food, extract nutrients from it, absorb them into the bloodstream and excrete undigested residues from the body.

Between the absorption of food and the eruption from the body of undigested residues, an average of 24 to 48 hours passes. The distance that the food bolus travels during this time, moving along the digestive tract, varies from 6 to 8 meters, depending on the individual characteristics of the person.

Oral cavity and pharynx

Oral cavity is the beginning of the digestive tract.

It is bounded in front by the lips, above by the hard and soft palate, below by the tongue and sublingual space, and on the sides by the cheeks. Through the pharynx (isthmus of the pharynx), the oral cavity communicates with the pharynx. The inner surface of the oral cavity, as well as other parts of the digestive tract, is covered with a mucous membrane, on the surface of which a large number of ducts of the salivary glands emerge.

The lower part of the soft palate and arches are formed mainly by the muscles involved in the act of swallowing.

Language- a mobile muscular organ located in the oral cavity and contributing to the processes of chewing food, swallowing, sucking. In the tongue, the body, apex, root and back are distinguished. From above, from the sides and partially from below, the tongue is covered with a mucous membrane, which fuses with its muscle fibers and contains glands and nerve endings that serve to sense taste and touch. On the back and body of the tongue, the mucous membrane is rough due to the large number of papillae of the tongue, which just recognize the taste of food. Those located at the tip of the tongue are tuned for the perception of sweet taste, those at the root - bitter, and the papillae in the middle and lateral surfaces of the tongue recognize sour.

From the lower surface of the tongue to the gums of the lower front teeth is a fold of mucous membrane, called the frenulum. On both sides of it, at the bottom of the oral cavity, the ducts of the submandibular and sublingual salivary glands open. The excretory duct of the third, parotid salivary gland, opens in front of the mouth on the buccal mucosa, at the level of the upper second molar.

Pharynx- a muscular tube 12-15 centimeters long, connecting the oral cavity with the esophagus, is located behind the larynx and consists of 3 parts: the nasopharynx, oropharynx and laryngeal part, which is located from the upper border of the laryngeal cartilage (epiglottis), which closes the entrance to the airways during swallowing before entering the esophagus.

Connecting the pharynx with the stomach, located behind the trachea - the cervical region, behind the heart - the thoracic and behind the left lobe of the liver - the abdominal.

The esophagus is a soft elastic tube about 25 centimeters long, which has 3 narrowings: upper, middle (aortic) and lower, and ensures the movement of food from the oral cavity into the stomach.

The esophagus begins at the level of the 6th cervical vertebra behind (the cricoid cartilage in front), at the level of the 10th thoracic vertebrae passes through the esophageal opening of the diaphragm, and then passes into the stomach. The wall of the esophagus is able to stretch when the food bolus passes, and then contract, pushing it into the stomach. Good chewing saturates the food with more saliva, it becomes more liquid, which facilitates and speeds up the passage of the food bolus into the stomach, so food should be chewed for as long as possible. Liquid food passes through the esophagus in 0.5-1.5 seconds, and solid food in 6-7 seconds.

At the lower end of the esophagus, there is a muscular constrictor (sphincter) that prevents back reflux (reflux) of the acidic contents of the stomach into the esophagus.

The wall of the esophagus consists of 4 membranes: connective tissue, muscle, submucosa and mucosa. The mucous membrane of the esophagus is a longitudinal folds of stratified squamous non-keratinized epithelium, providing protection from damage by solid food. The submucosa contains glands that secrete mucus, which improves the passage of the food bolus. The muscular membrane consists of 2 layers: inner (circular) and outer (longitudinal), which just allows you to ensure the movement of food through the esophagus.

A feature of the movements of the muscles of the esophagus during swallowing is the inhibition of the peristaltic wave of the previous sip by the next sip, if the previous sip did not pass into the stomach. Frequent repeated sips completely inhibit esophageal motility and relax the lower esophageal sphincter. Only slow sips and the release of the esophagus from the previous lump of food create the conditions for normal peristalsis.

It is intended for pre-treatment of the lumps of food that have entered it, which consists in the action of chemicals (hydrochloric acid) and enzymes (pepsin, lipase) on it, as well as its mixing. It has the appearance of a sac-like formation about 21-25 centimeters long and up to 3 liters in capacity, located under the diaphragm in the epigastric (epigastric) region of the abdomen (the entrance to the stomach and body of the stomach). In this case, the fundus of the stomach (upper section) is located under the left dome of the diaphragm, and the output section (pyloric part) opens into the duodenum in the right side of the abdominal cavity, partially passing under the liver. Directly in the pylorus, at the site of the transition of the stomach into the duodenum, there is a muscular constrictor (sphincter), which regulates the flow of food processed in the stomach into the duodenum, while preventing the return of food into the stomach.

In addition, the upper concave edge of the stomach is called the lesser curvature of the stomach (directed towards the lower surface of the liver), and the lower convex edge is called the greater curvature of the stomach (directed towards the spleen). The absence of rigid fixation of the stomach along its entire length (it is attached only at the point of entry of the esophagus and exit into the duodenum) makes its central part very mobile. This leads to the fact that the shape and size of the stomach can vary significantly depending on the amount of food contained in it, the tone of the muscles of the stomach and abdominals, and other factors.

The walls of the stomach from all sides are in contact with the organs of the abdominal cavity. Behind and to the left of the stomach is the spleen, behind it is the pancreas and the left kidney with the adrenal gland. The anterior wall adjoins the liver, diaphragm, and anterior abdominal wall. Therefore, the pain of some diseases of the stomach, in particular peptic ulcer, can be in different places depending on the location of the ulcer.

It is a misconception that the food eaten is digested in the order in which it entered the stomach. In fact, in the stomach, as in a concrete mixer, food is mixed into a homogeneous mass.

The wall of the stomach has 4 main shells - internal (mucous), submucosal, muscular (middle) and external (serous). Thickness mucous membrane of the stomach is 1.5-2 mm. The shell itself is covered with a single-layer prismatic epithelium containing gastric glands, consisting of various cells, and forms a large number of gastric folds directed in different directions, located mainly on the back wall of the stomach. The mucous membrane is divided into gastric fields with a diameter of 1 to 6 millimeters, on which there are gastric pits with a diameter of 0.2 mm, surrounded by villous folds. The excretory openings of the ducts of the gastric glands open into these dimples, which produce hydrochloric acid and digestive enzymes, as well as mucus that protects the stomach from their aggressive influence.

submucosa, located between the mucous and muscular membranes, is rich in loose fibrous connective tissue, in which the vascular and nerve plexuses are located.

Muscular membrane The stomach consists of 3 layers. The outer longitudinal layer is a continuation of the layer of the same name of the esophagus. At the lesser curvature, it reaches its greatest thickness, and at the greater curvature and fundus of the stomach, it becomes thinner, but occupies a large surface. The middle circular layer is also a continuation of the same layer of the esophagus and completely covers the stomach. The third (deep) layer consists of oblique fibers, the bundles of which form separate groups. The contraction of 3 multidirectional muscle layers ensures high-quality mixing of food in the stomach and the movement of food from the stomach to the duodenum.

The outer shell provides fixation of the stomach in the abdominal cavity and protects other shells from the penetration of microbes and from overstretching.

In recent years, it has been established that milk, which was previously recommended to reduce acidity, does not reduce, but somewhat increases the acidity of gastric juice.

It is the beginning of the small intestine, but is so closely connected with the stomach that it even has a joint disease - peptic ulcer.

This part of the intestine got its curious name after someone noticed that its length, on average, is equal to the width of twelve fingers, that is, about 27-30 centimeters. The duodenum begins immediately behind the stomach, covering the horseshoe head of the pancreas. In this intestine, the upper (bulb), descending, horizontal and ascending parts are distinguished. In the descending part, at the top of the large (vater) papilla of the duodenum, there is an orifice of the common bile duct and the pancreatic duct. Inflammatory processes in the duodenum, and especially ulcers, can cause disturbances in the functioning of the gallbladder and pancreas, up to their inflammation.

The wall of the duodenum consists of 3 membranes - serous (external), muscular (middle), and mucous (internal) with a submucosal layer. By using serous membrane it is attached almost motionless to the back wall of the abdominal cavity. Muscular membrane The duodenum consists of 2 layers of smooth muscles: outer - longitudinal and inner - circular.

mucous membrane has a special structure that makes its cells resistant to both the aggressive environment of the stomach and concentrated bile and pancreatic enzymes. The mucous membrane forms circular folds, densely covered with finger-like outgrowths - intestinal villi. In the upper part of the intestine in the submucosal layer are complex duodenal glands. In the lower part, in the depths of the mucous membrane, there are tubular intestinal glands.

The duodenum is the beginning of the small intestine, it is here that the process of intestinal digestion begins. One of the most important processes occurring in the duodenum is the neutralization of acidic gastric contents with the help of both its own juice and bile coming from the gallbladder.

Details

Knowledge of the physiology of the gastrointestinal tract is a necessary element of the foundation of medical education.

1. The main functions of the gastrointestinal tract.

2. Anatomy and physiology of the gastrointestinal tract: the location and functions of each department.

3. The main parts of the gastrointestinal tract and their function.

• Oral cavity (tongue, teeth, three pairs of salivary glands) and pharynx (formation of a food bolus + BEGINNING OF CARBOHYDRATE DIGESTION)
• Esophagus (skeletal muscle + smooth muscle - transportation of the food bolus)
• Stomach (accumulative function and digestion)
• Fundal part
• antrum
• pyloric part (limits the speed of advancement of the food bolus or chyme)
• Small intestine (functions: digestion, transport, absorption)
• Large intestine (transportation, absorption, reabsorption, formation and excretion of undigested food debris)

4. Oral cavity (tongue, teeth, three pairs of salivary glands) and pharynx (formation of food bolus + BEGINNING OF CARBOHYDRATE DIGESTION).

5. The secret of the salivary glands.

6. The main functions of saliva.

1. Wetting the crushed food and preparing the food bolus for swallowing
2. Initial hydrolysis of carbohydrates by salivary amylase
3. Neutralization of hydrochloric acid, which can be thrown from the stomach into the esophagus

7. Cellular structure of the salivary glands.

Cells are collected in clusters
Serous cells secrete the aqueous component of saliva
Mucoid cells secrete the viscous or mucous part of saliva - mucin (glycoprotein).

8. Anatomy of the salivary gland.

Acinar cells produce the enzyme amylase; Parietal cells produce bicarbonate;

9. Composition of saliva.
Alpha-amylase, mucin, bicorbanate, RNA-case, DNA-ase, peroxidase, kallikrein, etc. - volume of 1.5 liters per day.
The pH value - in the absence of food or thought about it - (6 - 7); during meals - (7-8)

10. Chemistry of digestion: carbohydrates.

food carbohydrates: vegetable and animal origin - starch, cellulose, amylopectin, glycogen, sucrose, lactose, glucose, fructose

Enzymes that carry out the hydrolysis of carbohydrates:
Amylase- saliva and pancreatic juice and enzymes of parietal digestion.

11. Autonomic nervous system.

Consists of sympathetic and parasympathetic divisions. The figure shows the effects that autonomous NS has on digestion.

12. Regulation of amylase secretion.

13. Swallowing reflex.

1 phase - arbitrary
Phase 2 - fast involuntary, lasting less than 1 s, occurs with reflex inhibition of breathing
Phase 3 - slow involuntary, lasts 5-10 s, is carried out by peristaltic movements of the esophagus wall and pressure drop

14. The mechanism of food bolus advancement through the esophagus.

15. Promotion of food through the stomach, electrical activity and contraction of the muscles of the stomach, evacuation of chyme.

16. Anatomical structure of the gastric wall.

17. Transport systems of parental cells providing HCl secretion and its regulation.

18. Activation of the pepsinogen proenzyme and its transfer to the active form - pepsin is carried out by partial proteolysis in the presence of H+ ions.

19. Cells of the stomach: their secret, function and localization.

20. Main functions of the gastric phase.

• Cumulative
• Enzymatic hydrolysis of proteins and partially fats, formation of chyme
• HCl - parietal cells (protective role - neutralization of bacteria & denaturation of proteins)
• Lipase–chief cells
• Pepsinogen-chief cells
• Protecting the mucosa by isolating bicorbanate and mucin.

21. Chemistry of digestion: proteins.

Squirrels(average intake -0.5-0.7 g/day/kg body weight --> enzymatic hydrolysis --> amino acids
Enzymes:

• endopeptidase (hydrolysis of the peptide bond between amino acids)
• exopeptidase (hydrolysis of amino acids with N(aminopeptidase) or C-terminus (carboxypeptidase)

22. Peptic ulcer.

The pathogenesis of peptic ulcer is multifactorial. and is primarily due mismatch between mucosal protective factors and mucosal damage factors.

Damaging factors:

• hydrochloric acid
• decreased blood flow
• decrease in the secretion of bicarbonates and mucus (the action of NSAIDs)
• Helicobacter pylori (gram-negative bacterium that destroys the mucous membrane, releasing toxic substances and causing inflammation)
• Nicotine (increases production of hydrochloric acid)

Protective factors:

• formation of a mucous lining (protective effect)
• bicarbonates (secreted by epithelial cells)
• blood flow (causes homeostasis of the gastric wall)
• prostaglandin E (stimulates bicarbonate and mucus production)

23. Factors determining the rate of passage of chyme from the stomach into the duodenum.

24. The main parts of the intestine and their function.

• Small intestine (digestion + absorption)
• Duodenum (25cm)
• Jejunum
• Ileum
• Pancreas
• Liver
• Large intestine (passes 1.5L of chyme per day - absorption and absorption)
• Colon (faecal production)
• Rectum
• Anus (voluntarily controlled sphincter - excretion of undigested residues)

25. Histology of the intestinal wall.

The wall of the small intestine, like the stomach, consists of 4 layers:

• Mucous membrane (inner layer)
• Epithelial layer (contains the gastric glands, in the case of the intestine, the brush border and crypts)
• Connective tissue layer (lamina propria)
• Muscular layer (inner -muscularis mucosae)
• Submucosal layer (middle)
• Muscle layer (outer layer)
• Serous membrane

26. Functional significance of mucus secretion for the gastrointestinal tract.

• Produced by specialized exocrine cells
• Mucous cells of the stomach
• Goblet intestinal cells
• Viscous secret
• glycoproteins = mucin
• Function - formation of a protective layer of the mucosa - lubricating, sliding effects
• Mucus secretion is controlled by the nervous system, neuropeptides of the enteric system, cytokines of immune cells
• With inflammation of the gastrointestinal tract - mucus secretion increases

27. Types of peristaltic contractions of the gastrointestinal tract.

Type of contractile activity of smooth muscles

• Tonic - minutes, hours
• phasic - seconds

Types of gastrointestinal wall contractions

• Peristaltic propulsion - the movement of chyme through the gastrointestinal tract
• Segmental - mixing

28. Enteral nervous system.

29. Reflexes in the gastrointestinal tract.

30. Regulation of digestion: autonomic and enteral nervous systems.

Regulation of the nervous and endocrine systems, local control
Vegetative reflex

• Can be excited both inside and outside the gastrointestinal tract
• Reflexes from other systems - either painful or emotional

Enteral reflex

• Submucosal ganglia & myenteric ganglia
• contraction, secretion

Gastrointestinal proteins

• Act as hormones or paracrino (locally)
• Gastrointestinal reflexes

31. Pancreatic secretion.

Cholecystokinin is secreted by the enteric endocrine cells of the duodenum into the blood, binds to receptors on the acinar cells of the pancreas and stimulates secretion.

HCI Stimulates the secretion of secretin, which causes the release of bicarbonate and water

32. Features of digestion in the duodenum.

• Determines the rate of gastric emptying and the strength of contractions of its smooth muscles (reflex);
• pH neutralization, bile secretion & enzymes;
• secretion of pancreatic juice;
• The movement of chyme towards the small intestine;

33. Nature and mechanism of secretion of gastrointestinal enzymes.

Enzymes are synthesized and secreted by exocrine glands (salivary, gastric and intestinal glands and pancreas).
They are of a protein nature.
Secreted by exocytosis
Formed from an inactive proenzyme
Excretion is controlled by the nervous system, hormonally and paracrinely

34. Enzymes of the gastrointestinal tract.

35. The structure of the epithelium of the small intestine (brush border).

• Villi and microvilli
• Lymphatic vessels
• Arterial and venous vessels
• Communication with the portal system of the liver
• Chylomicrons (mixture of fats with cholesterol)

36. Chemistry of digestion: fats.

• With food, triglycerides enter the body mainly. In a small amount - phospholipids and cholesterol.
• A small amount of fat dissolved in the oil is exposed to the action of gastric lipase and absorbed in the stomach.
• More fat particles require bile emulsification for enzymatic degradation, transport and absorption.
• Enzymes: lipases, colipases & phospholipases
• Triglycerides --> Monoglycerides & Free Fatty Acids
• Free cholesterol consumed with food is absorbed directly

37. Secretion and production of bile.

Bile is produced by hepatocytes
The components of bile are:

• Bile salts (= steroids + amino acids). Detergents capable of reacting with water and lipids to form water-soluble fatty particles
• Bile pigments (result of degradation of hemoglobin)
• cholesterol

Bile is concentrated and deposited in the gallbladder.
Bile is released from the gallbladder when it contracts.

38. The process of emulsification of fats and fat-soluble vitamins (A, D, E, K) with bile.

39. Intestinal phase of fat degradation and absorption.

Colipase releases bile, lipase breaks down fats, micelles are formed. Fat-soluble vitamins are absorbed.

40. Chemistry of digestion: carbohydrates.

41. Intestinal phase of degradation and absorption of carbohydrates.

Hydrolysis to simple sugars
suction / transport

• Na+/glucose or galactose symport (apical membrane)
• fructose is transported by GLUT5 (apical and basolateral membranes)
• Transport of glucose across the basolateral membrane by the GLUT2 transporter into the capillary

42. Intestinal phase of protein degradation and absorption.

Hydrolysis to tri-dipeptides and amino acids;
Membrane transport: H+, Na+ cotransport (CAT1, CAT2 transporters) and transcytosis through the enterocyte and then into the capillary;

43. Localization of absorption and secretion sites along the gastrointestinal tract.

44. Mechanism of absorption of vitamin B12.

45. The mechanism of absorption of iron ions.

46. ​​Cation-transport channels.

47. Exchange of ions and water in the digestive tract.

ions: H+, K+, Na+, HCO3-, Cl-
They come from the intestinal fluid into the lumen of the gastrointestinal tract through the apical and basolateral membranes of the epithelium
Water follows an osmotic gradient

48. Fluid exchange in the gastrointestinal tract: total - 9 liters, of which 5 liters from tissues and 2 liters p / os.

49. Absorption in the large intestine.

50. Secretion of ions in the large intestine.

51. Main functions of the large intestine.

Bacterial fermentation
Absorption and secretion of ions
Water reabsorption about 1.4 liters/day
Defecation reflex and excretion of fecal matter

52. General principles of absorption in the gastrointestinal tract.

In the process of digestion, the food bolus undergoes mechanical and enzymatic decomposition into macromolecules.
Small pieces of food are the object of action of bile and food enzymes.
The specific pH value for various parts of the gastrointestinal tract is characteristic.
The acidic pH is in the stomach.
Alkaline pH - in the mouth and intestines.
Absorption of nutrients is mainly in the small intestine.
Absorption of ions & water - large intestine.