What is the duodenum made of. Duodenum: location, structure and functions

In the digestive system, this organ is assigned one of the most difficult
roles. And it is she who suffers most from bad eating habits.
This is due to the fact that the duodenum is the initial
section of the small intestine. It is into it that the food lump from the stomach enters.

The duodenum encloses the horseshoe pancreas in the upper right abdomen. Length twelve duodenal ulcer is 20-30 cm, which is equal to about 12 fingers. The finger is an ancient measure of length equal to the transverse width
finger. The normal bowel is shaped like a U, V, or S.

It is customary to distinguish 4 sections of this intestine:

• upper
• descending
• horizontal
• ascending.

The duodenum begins with an expansion called
bulb duodenum. Bulb size may vary
depending on the tone of the intestine and the degree of its filling. But on average
the duodenal bulb reaches a diameter of 4 cm and a length of 3-4
see The duodenum ends with a transition to the jejunum,
forming a duodenal-skinny bend.

The upper part of the intestine starts from the stomach and is located in the direction
to the right and back along the right surface of the spine. Descending part
9-12 cm long from the bend of the upper intestine, it descends almost vertically and
ends at the inferior flexure of the duodenum.

The descending part of the duodenum is located in the abdominal cavity
in such a way that it comes into contact with the right kidney, renal vessels,
the initial part of the ureter, with the colon. From within to her
fits the head of the pancreas. This part of the intestine is covered in front
transverse colon and its mesentery.

The horizontal part is located below the mesentery of the transverse colon
intestines. The ascending part, 6-13 cm long, connects to the jejunum,
forming a bend, which is connected with the left leg of the diaphragm, to which it is firmly
fixed.

Provide innervation vagus nerves and plexuses - celiac, upper
mesenteric, hepatic, upper and lower gastric and
gastroduodenal.

The entire intestinal wall is permeated with nerve branches. The cavity is lined
villi, which are covered with microvilli, which increase the surface
cells by 14-39 times.

Two arteries supply blood to the duodenum
upper and lower pancreatoduodenal.

There are cases when the mesenteric aorta compresses the duodenum
intestine in the area of ​​its horizontal part, which leads to its partial
obstruction.

Functions

The ducts of the two main digestive glands flow into this intestine. One is called the bile duct and flows out of the liver, the other is the pancreas, from the pancreas. Under the action of their enzymes, digestion of proteins occurs here, which began in the stomach, carbohydrates, their digestion began in the oral cavity, and fats. This is the so-called cavity digestion. But abdominal digestion cannot provide absorption.

Therefore, the elements formed as a result of splitting enter the brush borders of the intestine.

It is here that the final stage of the breakdown of proteins, carbohydrates and fats occurs already under the action of intestinal enzymes proper and their absorption. In addition, absorption of calcium, magnesium and iron occurs in the duodenum.

Digestion of carbohydrates

Carbohydrates are organic compounds that enter the body from plant products. They account for half of the calories a person needs per day. Thus, carbohydrates are the main source of energy obtained from food.

Sources of carbohydrates are grains, legumes, vegetables, fruits, honey, sugar. They enter the body as part of starch, glycogen, sucrose, lactose, fructose and glucose. In addition, plant foods contain ballast substances, they consist of cellulose and dietary fiber, which are not digested.

When carbohydrates are broken down in the duodenum, complex processes occur with the release of a large number of various enzymes. The high specificity of these enzymes makes it possible to break down all types of saccharides.

If for some reason the secretion of any enzymes is impaired, this leads to intolerance to lactose contained in milk, sucrose contained in ordinary sugar, trehalose contained in mushrooms. This intolerance is characterized by the appearance of profuse diarrhea and abdominal pain after ingestion of foods containing these carbohydrates.

Protein digestion

Proteins form the basis of cells and tissues. They contain essential amino acids. Complete sources of protein, that is, containing all the essential amino acids, are animal proteins, meat, fish, dairy products, egg protein.

The breakdown of proteins begins in the stomach. In the duodenum, it continues first by the action of pancreatic enzymes, and then by its own intestinal enzymes.

As a result of this process, a large number of peptides are released, which play an important role in providing the body's defense function.

Digestion of fats

Fats are second only to carbohydrates in providing energy to the body. They contain essential unsaturated fatty acids. Essential means that the body itself is not able to synthesize them. Thus, the intake of fats in the body is necessary.

Partially, 10% of fat is processed in the stomach. In the duodenum, it is cleaved first by bile acids and pancreatic enzymes, and then by intestinal enzymes proper.

Regardless of the quantity and quality of fat supplied to the body, it is completely absorbed, no more than 5% of fat is lost with feces.

Preservation of body homeostasis

Homeostasis is the constancy of the internal environment of the body. Back in the 19th century, scientists drew attention to the fact that the composition of blood and lymph remained virtually unchanged under various environmental conditions. Studying this issue, Soviet scientists found that it provides the gastrointestinal tract. And with a deeper study, they realized that the main function of maintaining homeostasis is performed by the duodenum.

Regardless of what food has entered the body, the food mass (chyme) that comes out of the duodenum always has almost the same composition. It is closer to blood counts than to the composition of the food eaten.

How is this achieved? If the food is balanced and contains all the necessary components, then splitting and absorption occurs in the duodenum, as described above. If the food contains an excess of one component and a lack of others, then the body takes the missing elements from its reserves, most often from the blood.

If such a bias in the incoming food persists for a long time, this may adversely affect the composition of the blood. This process is badly affected by starvation, mono-diets, separate meals.

It has been proven that while the mechanisms of maintaining homeostasis in the body are not disturbed, the effects of the external environment are not able to have a damaging effect on it.

Diseases of the duodenum

As noted above, the food lump from the stomach enters the duodenum. This makes it vulnerable to increased acidity of gastric juice. As a result, the duodenum is susceptible.

Perhaps inflammation of the wall of the duodenum, often only the mucous membrane. This disease is called.

An isolated lesion of the mucous membrane of the duodenal bulb is called bulbitis, the area of ​​​​the major duodenal papilla is called sphincteritis.

According to the Central Research Institute of Gastroenterology, the frequency of intestinal diverticulum has increased over the past decades in economically developed countries. This is associated with insufficient intake of coarse fiber in food.

- this is a congenital or acquired protrusion of the wall of a hollow organ. Most often it is localized in the duodenum.

A disease that affects both the small and large intestines.

They can affect the intestines either through infection from other people or through poor-quality food, which leads to poisoning.

Helminthiases, infection or pork tapeworm.

Prevention measures

Careful attention to your diet will protect the duodenum from damage.

1. Food that is too hot or too cold should not be eaten.
2. Chew food thoroughly so that gruel enters the duodenum, because the stomach and intestines do not have teeth.
3. You can not drink food with cold drinks, as this opens the sphincter, and all food enters the duodenum undigested by gastric juice.
4. Eat in a good mood and take your time.
5. Monitor the normal acidity of the stomach.
6. Follow the rules of hygiene - wash your hands and products.

duodenum) is the initial section of the small intestine, which immediately follows the stomach. The next section of the small intestine continues the duodenum - the jejunum. The length of the intestine is equal to 12 folded fingers across ( approx. 25 - 30 cm), which is why it has such a name.

Duodenum has four parts:
Horizontal ( upper) part is at the level of the first lumbar vertebra. Directly above it is the right lobe of the liver;
The descending part, curving downward, reaches the third lumbar vertebra and comes into contact with the right kidney;
Horizontal ( lower) part begins with a new bend to the left. Behind it is the inferior vena cava and the aorta;
The ascending part is located at the level of the second lumbar vertebra, bends sharply upward and passes into the jejunum.

In addition, in the first section of the intestine, a small extension is distinguished, which is called the bulb. In humans, the duodenum is shaped like a loop or horseshoe, the bend of which encircles the head of the pancreas. The walls of the duodenum have the same structure as the rest of the small intestine. But there is something that fundamentally distinguishes the duodenum - it is a large Vater papilla. It represents a small anatomical structure the size of a match head, protruding from the mucous membrane of the descending intestine. Behind it hide the two largest glands in the body: the liver and pancreas. They are connected to the papilla of Vater through the main pancreatic and common bile ducts. Sometimes, a small papilla may be located next to the papilla of Vater, which opens an additional duct coming from the pancreas.

The intestinal wall is represented by the following layers:
Outdoor ( serous) shell;
Muscular membrane with circular and longitudinal layers and nerve nodes;
The submucosa contains many lymphatic and blood vessels. It collects the intestinal mucosa in semilunar, spiral folds. The height of the highest folds is 1 cm. Unlike the folds of the stomach, these folds do not stretch and do not disappear when the intestine is stretched with food gruel;
The mucous membrane forms many villi. In the duodenum, unlike the rest of the small intestine, they are wider and shorter.

Bookmark and formation of the intestine in the period embryonic development together with the gastrointestinal tract is carried out from 4 to 12 weeks.

duodenum functions

Diseases of the duodenum

In order for an ulcer to occur, the following conditions are necessary:
Frequent stressful situations, which are accompanied by dysfunction of the autonomic nervous system followed by spasm of the blood vessels of the stomach and duodenum 12. In turn, this leads to a violation of tissue trophism, which makes the mucous membrane more vulnerable to negative factors;
Often drinking alcohol, spicy, fried foods, which provoke the synthesis of hydrochloric acid in excess;
Uncontrolled intake of drugs that irritate the mucous membrane, such as: aspirin, reserpine, diclofenac, etc.

The main signs of an ulcer:
Pain on an empty stomach of a aching nature in the epigastric region, usually at night. She can give back. Stopped by eating after about 30 minutes. Sometimes the pain can be localized in the gallbladder, due to dyskinesia bile ducts, which occurs under the influence of reflex and humoral factors from the altered intestinal mucosa.
After 2 hours, heartburn and belching with a sour taste occur;
Bloating and frequent constipation.

An ulcer is dangerous for its complications, which include: ( malignancy) degeneration into cancer, bleeding, ( perforation) perforation. Often the healing of the ulcer is accompanied by the formation of stenosis ( constriction) pylorus or bulb, followed by deformation of the intestinal walls. A perforated ulcer is a formidable condition that is dangerously fatal.

Among the anomalies of the duodenum 12, which may occur even during fetal development, there may be atresia. It occurs during the laying of the organ, that is, at 2 months of pregnancy. Atresia is characterized by the absence of a bowel lumen. The pathology in the newborn is manifested by frequent regurgitation, lack of intestinal motility, and general exhaustion.

Bulbit- inflammation of the adjacent part of the duodenum 12 ( bulbs) to the stomach. The disease rarely occurs on its own. Usually it is accompanied by gastritis, gastric ulcer and duodenal ulcer. Lack of treatment contributes to the formation at the site of inflammation, first erosion, and then ulcers. Symptoms of the disease are very similar to peptic ulcer disease.

Benign tumors of the duodenum include polyps. Very often they are discovered only after death during an autopsy, since their intravital diagnosis is difficult. In addition, the symptoms characteristic of polyps strongly resemble a tumor of the bile ducts or the pylorus.

Diagnostics

Radiography is performed to clarify the diagnosis using a radiopaque substance. In the picture or on the screen with fluoroscopy, the doctor can only see the outline of the intestine. In pathology, the following are clearly distinguishable: niche, narrowing, deformity, tumors.

Ultrasound is rarely performed. With it, you can determine the size and location of the abdominal organs, including the duodenum.

Treatment and prevention

In addition to traditional medicines, remedies will be useful traditional medicine, for example, a collection of chamomile, lemon balm, shepherd's purse, centaury. Herbs will have an anti-inflammatory, healing effect.

All ulcers must adhere to a diet, especially during an exacerbation. The menu of such a diet excludes spicy, fried foods, as well as alcoholic beverages.

The course of treatment is designed for 2 weeks in autumn and spring, after which it is necessary to follow the maintenance treatment prescribed by the doctor.

How to treat long-term non-healing ulcers? Complicated peptic ulcer disease, as well as long-term non-healing ulcers, are treated only with the help of surgery. During it, the affected intestine ulcer is removed.

Prevention of diseases of the duodenum is reduced to compliance with the diet provided for by the diet. It is important to avoid the use

The duodenum got its name due to its length, which is approximately 12 transverse dimensions of a finger. The colon begins at the duodenum 12. Where is it located and what are its main functions?

Structure and functions of the body

The duodenum has 4 sections:

• upper horizontal;
• descending;
• bottom horizontal;
• ascending.

The upper horizontal section of the intestine is considered the initial and is a continuation of the pylorus. The upper section has a round shape, and therefore it is also called an onion. Its length is 5-6 cm. The descending section, whose length is 7-12 cm, is located near the lumbar spine. It is in this section that the ducts of the stomach and pancreas are removed. The length of the lower horizontal section is about 6-8 cm. It crosses the spine in the transverse direction and passes into the ascending section. The ascending part is 4-5 cm long. It is located on the left side of the spinal column.

The duodenum is located within the 2-3 lumbar vertebrae. Depending on the age and weight of the person, the location of the intestine may vary.

The duodenum performs secretory, motor and evacuation functions. The secretory function is to mix the chyme with digestive juices that enter the intestine from the gallbladder and pancreas. The motor function is responsible for the movement of the food gruel. The principle of the evacuation function is to evacuate the chyme to the subsequent sections of the intestine.

Causes of pathology

Inflammation of the intestine, as a rule, occurs against the background of gastrointestinal disorders. Causative factors include viral infection, inflammation of the lining of the stomach or gallbladder, diarrhea, low blood flow to the intestines.

Inflammation of the intestine is often caused by an infection with Helicobacter pylori. This bacterium is in the stomach and does not manifest itself in any way. Its presence in the body leads to increased production gastric acid, which further irritates the duodenal mucosa. Left untreated, the bacterium can cause intestinal ulcers.

Diseases of the duodenum can develop against a background of severe stress or surgery. In some cases, non-steroidal anti-inflammatory drugs (NSAIDs), smoking, or excessive alcohol consumption may be the underlying cause.

Inflammation of the duodenum 12 can be caused by food poisoning, eating spicy or fatty foods, as well as a foreign object. It has been proven that some pathologies of the intestine can be hereditary. Pathogenic factors such as diabetes and gallstone disease.

Symptoms of duodenal disease have their own clinical picture and may differ from each other.

peptic ulcer

characteristic symptom peptic ulcer is an indigestion. The patient has frequent and liquid stool. Often, patients have a complete intolerance to dairy products and fruits. If the patient has a sharp weight loss in the presence of increased appetite, then this may indicate that the duodenum is inflamed.

If ulcers have affected an organ such as the duodenum, the symptoms of the disease may manifest in a characteristic yellow coating in the language. This is due to spasms of the bile ducts, which lead to stagnation of bile. In the advanced stages of the disease, pain appears in the right side and the skin acquires a yellow tint.

With a duodenal ulcer, cicatricial changes in the stomach occur, which as a result leads to the evacuation of food. Congestion in the stomach leads to nausea and vomiting. Often after vomiting general state the patient improves for a while.

Pain is a characteristic symptom of peptic ulcer disease. It can be aching or sharp, prolonged or paroxysmal. As a rule, the pain subsides after eating, which is why they are also called "hungry." This symptom occurs in 70-80% of patients. Pain is most often felt in the lower back or thoracic region. In some cases, patients with duodenal ulcer may complain of pain in the collarbone.

Colon cancer and duodenitis

If a patient has been diagnosed with colon cancer, the symptoms of the disease may manifest as jaundice, fever, and itching. With first-degree cancer, there is pain. It occurs as a result of compression of the nerve fibers by the tumor or blockage of the bile duct. The pain syndrome is most often felt in the right hypochondrium, but in some cases the pain can spread to other organs.

One of the symptoms of the disease is itchy skin. It appears due to the high content of bilirubin in the blood and irritation of skin receptors with bile acids. Against the background of itching, the patient develops agitation and insomnia.

No less common disease of the duodenum is duodenitis. This ailment manifests itself in the form of distension of the stomach after eating, dull and constant pain, nausea, loss of appetite, vomiting. In patients with this diagnosis, palpation of the epigastric region is painful.

Proper nutrition

For any of the diseases of the duodenum, the patient is prescribed a diet. diet combined with complex treatment eliminates exacerbations and significantly improves the general condition of the patient. If the duodenum is inflamed, then, first of all, foods that can stimulate the production of gastric acid are excluded from the diet. Such foods include sour fruits, fatty broths, fresh vegetable and fruit juices, mushrooms, smoked, salted, fried and pickled foods, and spices. Sweet carbonated and alcoholic drinks are also prohibited.

The menu should contain easily digestible fats, for example vegetable oil, cream or margarine.

It is necessary to limit the intake of products that in any way irritate the mucous membrane. In order to avoid overloading the stomach and exacerbating the disease, it is not recommended to eat cold or hot dishes. Food should be at room temperature.

It is forbidden to eat foods that have mechanical irritation. These foods include raw vegetables and fruits, beans, peas, and whole grains. With inflammation of the duodenum, doctors recommend excluding mustard, vinegar, salt and other seasonings from the diet.

Meals should be frequent. You need to eat about 4-5 times a day. Between meals should be at least 3-4 hours. Preference should be given to dishes cooked in boiling water or steamed.

Therapeutic measures

Symptoms and treatment of duodenal pathologies are determined by the doctor after an appropriate examination. If the diagnosis confirmed peptic ulcer, then the patient is prescribed drug treatment. To destroy the Helicobacter pylori bacteria, the patient is prescribed a course of antibiotics. These drugs include Erythromycin, Clarithromycin, Metronidazole and Ampiox.

To reduce the production of hydrochloric acid, doctors prescribe Omeprazole, De-Nol and Ranitidine.

These drugs also have a bactericidal effect. At severe pain doctors prescribe antacids.

Surgical treatment of duodenal ulcer is quite rare. Indications for surgery are complications of the disease. In this case, during the operation, the surgeon can remove the affected area of ​​​​the intestine, this helps to reduce the production of secretion and the level of hydrochloric acid.

Treatment of patients with a diagnosis of duodenal cancer is carried out with the help of surgery. The type of operation is chosen depending on where the malignant tumor is located and at what stage of development the disease is. A small tumor is removed laparoscopically, that is, through minimal punctures in the abdominal wall. If the tumor big size, then it is removed by extensive surgery. In this case, the doctor removes the outlet section of the stomach and the omentum adjacent to it, part of the duodenum, gallbladder and head of the pancreas.

If a malignant tumor was diagnosed at a late stage, then this greatly complicates the operation. In this case, the surgeon removes not only the tumor, but also the affected The lymph nodes and adjacent tissues.

In addition to surgical treatment, the patient is prescribed radiation and chemotherapy. Such treatment helps prevent relapses and prolongs the life of the patient.

Patients diagnosed with duodenitis are prescribed medication and physiotherapy. In acute or chronic duodenitis, doctors prescribe painkillers: Drotaverine, No-shpu and Papaverine. To reduce the level of acidity of gastric juice, antacid drugs are prescribed, such as Omeprazole or Almagel.

All about the drug Almagel and in what cases to take it -.

If duodenitis has developed against the background of helminthic invasion, then treatment is carried out with antibiotics. To normalize the work of the intestine, drugs are prescribed that enhance its peristalsis. These drugs include Maalox and Domperidone.

As an auxiliary treatment, physiotherapy is performed. Ultrasound, heating, paraffin applications and magnetotherapy are considered effective. Physiotherapeutic procedures allow you to normalize the blood supply and lymph flow of the abdominal organs, relieve pain.

An important organ of human digestion is the duodenum, which is located immediately behind the stomach and begins small intestine. It is small in size, no more than 30 cm long, has 4 departments. The shape of the duodenum is different, there are C-shaped, V-shaped and U-shaped. The duodenum is the shortest, but at the same time the thickest segment.

This organ has a special structure of the mucous layer, which is resistant to aggressive gastric juice, pepsin and enzymes. The organ is fixed by means of connective fibers that are located on the intestinal wall and pass into the retroperitoneal space.

The duodenum 12 consists of the following departments.

1. The initial upper horizontal - located immediately after the stomach, has the shape of a ball, its length is only 5 cm. Like the pylorus, it has longitudinal folds. In another way, this department is called the bulb.
2. The section located to the right of the spine is descending, its length is 12 cm, it forms the lower curvature, passing into the next section. In this segment, the duodenum receives the ducts of the pancreas and the bile section of the stomach. A special sphincter of Oddi acts as a smooth muscle that regulates the amount and time of bile supply to the lumen of the organ. Some diseases of the duodenum are associated with a violation of this sphincter, which opens voluntarily.
3. The horizontal lower section has a length of 8 cm, it is located from right to left, ending with the last ascending section.
4. The ascending section has a length of 5 cm, is located to the left of the spine, forms a curvature. Behind the last section of the organ, the mesenteric part of the small intestine begins. Another important sphincter is located at the transition, which prevents the reverse penetration of food.

Localized duodenum at the level of the lumbar segment of the spine L2-L3. This is a standard structure, but depending on the weight, constitution, age of a person, the organ can move lower. It has a single circulatory system, and lymph outflow is carried out through the anterior and posterior wall of the pancreatic head.

Functions

The main process of digestion and absorption of nutrients begins in the duodenum 12, it is this organ of the gastrointestinal tract that is responsible for neutralizing the acid for safe passage through the following departments.

The main functions of the body.

1. The production of enzymes is regulated by the duodenum, but the organ itself secretes juice - these are the main functions of the organ that ensure safe digestion.
2. Functions of motility and evacuation - the organ moves the chyme that came from the stomach into the small intestine, pre-enriching it with enzymes.
3. Secretory - Brunner's glands are actively involved in the secretion of juice for the normal passage of the food bolus.

These are the main functions of the department, which allow food to pass from the stomach safely without irritating the mucous layer of the small intestine.

Frequent pathologies

Different parts of the duodenum are often disturbed in parallel with diseases of the stomach. Pathologies can be infectious and non-infectious, depending on the cause.

Possible diseases of the duodenum and their causes.

1. Inflammatory disease of the mucous layer or duodenitis - poor nutrition.
2. Peptic ulcer of the duodenum and stomach - the bacterium Helicobacter.
3. Malignant organ formation - ignoring the symptoms of other ailments.

Duodenitis

The most common disease of the digestive organ is duodenitis. This is an inflammation of the mucous membrane, which leads to a malfunction of the organ and damage to the stomach. Pathology develops on its own or against the background of other disorders of the gastrointestinal tract, including a stomach ulcer or gastritis. The main cause of duodenitis is malnutrition, and this factor can provoke other diseases of the duodenum.

Symptoms of inflammation of the organ appear acutely, severe pain and dyspepsia begin.

Secondary pathology occurs in response to diseases such as infection, toxic-infectious lesions of the stomach, food poisoning, alcoholism.

peptic ulcer

Peptic ulcer of the stomach and duodenum is diagnosed second in frequency. This is a serious pathology of the chronic course, which occurs under the influence of the Helicobacter bacterium. It produces toxic elements that provoke peptic ulcer disease. In this case, two human organs are simultaneously affected, both the intestine itself and the stomach.

Treatment for peptic ulcer disease includes neutralizing the Helicobacter bacteria, normalizing stomach acidity through antibiotic treatment, and prescribing a proper diet.

Tumor

Tumor processes occur more often in older people with peptic ulcer disease. Symptoms of cancer are hidden behind other pathologies, so diagnosis is usually carried out at the last stage of the disease. Malignant tumors arise a second time, due to the germination of tissues of neighboring organs. The treatment of such a pathology is only surgical, but chemotherapy and a drug course are carried out in parallel.

Disease symptoms

Regardless of the nature of the disease that has arisen, the duodenum gives similar symptoms associated with a violation of the structure, secretory and motor function. Typical signs of pathology often appear already in the process of active development of the disease, therefore, it is necessary to check the state of the organ even with minor changes in the state, when mild symptoms appear.

What signs accompany diseases of the duodenum?

1. Symptoms of dyspepsia: the appearance of heartburn, bad breath, nausea, vomiting. Some pathologies provoke constipation, but carry-over is more often observed.
2. Appetite disturbance: with peptic ulcer, symptoms of severe pain appear, the treatment of which is carried out by the usual meal. In the case of duodenitis, appetite decreases.
3. Psychological discomfort: the patient has mild symptoms of a depressive disorder, unreasonable irritation, loss of strength, decreased performance and apathy.
4. Bleeding: symptoms of anemia appear, the skin turns pale. Most diseases cause chronic bleeding, which is detected only during instrumental diagnostics.

Each disease can result in complications: perforation, scarring, precancerous condition, pancreatitis.

Treatment

What treatment is used in case of duodenal pathologies?

1. Drug treatment: analgesics, sedatives, anti-inflammatory drugs, antacids.
2. Physiotherapy treatment: electrophoresis, therapeutic baths, warming compresses.
3. Surgical treatment: in advanced cases, a radical removal of part of the organ is prescribed.
4. Prevention of complications: consists in the correct rehabilitation of the patient and the appointment home treatment in the postoperative period.

The duodenum reacts to a person's lifestyle, therefore a healthy diet, the absence of bad habits, and mental health prevent many diseases.

Conservative or surgical treatment of the duodenum restores the normal function of the organ, but to maintain it, it is necessary to constantly follow prevention, which includes a special diet, taking vitamins, and regular examination by a gastroenterologist.

The intestine goes from left to right and backwards, then turns down and descends in front of the right to level II or the upper edge of the III lumbar vertebra; then it turns to the left, is located at first almost horizontally, crossing the inferior vena cava in front, and then goes obliquely upwards in front of the abdominal and, finally, at the level of the body of the I or II lumbar vertebra, to the left of it, passes into the jejunum. Thus, it forms, as it were, a horseshoe or an incomplete ring, covering the top, right and bottom of the head and partly the body.

The initial section of the intestine is the upper part, pars superior, which at first is somewhat expanded and forms an ampulla, ampulla; the second section is the descending part, pars descendens, then the horizontal (lower) part, pars horizontalis (inferior), which passes into the last section - the ascending part, pars ascendens. When the upper part passes into the descending one, the upper flexure of the duodenum, flexura duodeni superior, is noticeable, and when the descending part passes into the horizontal, the lower flexure of the duodenum, flexura duodeni inferior. Finally, when the duodenum passes into the jejunum, the steepest duodenal jejunal bend, flexura duodenojejunalis, is formed. The muscle that suspends the duodenum, m. suspensorius duodeni, which is a muscular-connective tissue cord attached to the left leg of the diaphragm. The length of the duodenum is 27-30 cm, the diameter of the widest descending part is 4.7 cm. A slight narrowing of the lumen of the duodenum is noted at the level of the middle length of the descending part, in the place where it is crossed by the right colon artery, and on the border between the horizontal and ascending parts where the intestine is crossed from top to bottom by the upper mesenteric vessels.

The wall of the duodenum consists of three membranes: mucous, muscular and serous. Only the beginning of the upper part (over 2.5-5 cm) is covered with peritoneum on three sides; the descending and lower parts are located retroperitoneally and are covered with adventitia.

The muscular membrane, tunica muscularis, of the duodenum has a thickness of 0.3-0.5 mm, more than the thickness of the rest of the small intestine. It consists of two layers of smooth muscles: the outer one is the longitudinal layer, stratum longitudinale, and the inner one is the circular layer, stratum circulare.

The mucous membrane, tunica mucosa, consists of an epithelial layer with a connective tissue plate underlying it, a muscular lamina of the mucous membrane, lamina muscularis mucosae, and a layer of submucosal loose fiber that separates the mucous membrane from the muscle. In the upper part of the duodenum, the mucous membrane forms longitudinal folds, in the descending and horizontal (lower) parts - circular folds, plicae circulares. Circular folds are permanent, occupying 1/2 or 2/3 of the circumference of the intestine. In the lower half of the descending part of the duodenum (rarely in the upper half), on the medial portion of the posterior wall, there is a longitudinal fold of the duodenum, plica longitudinalis duodeni, up to 11 mm long, distally it ends with a tubercle - the major papilla of the duodenum, papilla duodeni major, on top of which is located the mouth of the common bile duct and the pancreatic duct. Slightly above it, at the top of the small duodenal papilla, papilla duodeni minor, there is an orifice that occurs in some cases.

The mucous membrane of the duodenum, like the rest of the small intestine, forms small outgrowths on its surface - intestinal villi, villi intestinale, up to 40 per 1 mm 2, which gives it a velvety appearance. The villi are leaf-shaped, their height varies from 0.5 to 1.5 mm, and their thickness varies from 0.2 to 0.5 mm.

In the small intestine, the villi are cylindrical, in the ileum they are clavate.

In the central part of the villus there is a lymphatic capillary. Blood vessels are directed through the entire thickness of the mucous membrane to the base of the villus, penetrate into it, and, branching into capillary networks, reach the top of the villus. Around the base of the villi, the mucous membrane forms depressions - crypts, in which the mouths of the intestinal glands, glandulae intestinales, open. The glands are straight tubes reaching their bottom of the muscular plate of the mucous membrane. They are located throughout the mucous membrane of the small intestine, making up an almost continuous layer and interrupted only in the places of occurrence of group lymphatic follicles. The mucous membrane of the duodenum, villi and crypts are lined with a single-layer prismatic epithelium with an admixture of goblet cells; in the deepest part of the crypts are cells of the glandular epithelium. Branched tubular duodenal glands, glandulae duodenales, lie in the submucosa of the duodenum; most of them are in the upper part, their number decreases downwards. Throughout the mucous membrane of the duodenum there are single lymphatic follicles, folliculis lymphatici solitarii.

Topography of the duodenum.

The upper part of the duodenum is located to the right of the body of the I lumbar or XII thoracic vertebrae, for several centimeters from the pylorus intraperitoneally, so it is relatively mobile. From its upper edge follows the hepatoduodenal ligament, lig. hepatoduodenale.

The upper edge of the upper part adjoins the square lobe of the liver. The gallbladder is adjacent to the anterior surface of the upper part, which is sometimes connected to it by a small peritoneal ligament. The lower edge of the upper part is adjacent to the head of the pancreas. The descending part of the duodenum is located along the right edge of the bodies of I, II and III lumbar vertebrae. It is covered by the peritoneum on the right and in front. Behind the descending part is adjacent to the medial part of the right kidney and to the left - to the inferior vena cava. The middle of the anterior surface of the duodenum is crossed by the mesentery of the transverse colon with the right colonic artery embedded in it; above this place, the right flexure of the colon is adjacent to the anterior surface of the descending part.

At the medial edge of the descending part is the head of the pancreas, along the edge of the latter passes the anterior superior pancreatoduodenal artery, which gives feeding branches to both organs. The horizontal part of the duodenum is at the level of the III lumbar vertebra, crossing it from right to left, in front of the inferior vena cava; lies retroperitoneally. It is covered with peritoneum in front and below; only the place of its transition into the jejunum is located intraperitoneally; in this place, to its antimesenteric edge from the base of the mesentery of the transverse colon, there is a peritoneal upper duodenal fold, plica duodenalis superior (plica duodenojejunalis). The ascending part reaches the body of the I (II) lumbar vertebra.

At the border of the horizontal and ascending parts, the intestine is crossed almost vertically by the upper mesenteric vessels (artery and vein), and to the left - the root of the mesentery of the small intestine, radix mesenterii. The posterior surface of the ascending section is adjacent to the abdominal aorta. The upper edge of the lower part of the duodenum adjoins the head and body of the pancreas.

The duodenal-skinny bend, flexura duodenojejunalis, is fixed by the muscle that suspends the duodenum, m. suspensorius duodeni, and a bunch. The muscle is made up of smooth muscle fibers; the upper end starts from the left leg of the lumbar part of the diaphragm, the lower end is woven into the muscular membrane of the intestine .

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