The esophagus is a hollow organ, which is a narrow and fairly mobile tube up to 25 cm long that connects the pharynx and stomach. The rudiments of the esophagus appear already in the first month of embryonic development, and by the time the child is born it is quite well formed, the diameter of its lumen is 7-8 mm, and its length is up to 16 cm.

Location

Schematic representation of the esophagus (in the center) and the organs located around it.

Among specialists, it is customary to correlate the beginning and end of the esophagus with the visible and permanent bone formations of the human skeleton:

• it begins at the VI cervical level (in front, this is the area of ​​the lower edge of the cricoid cartilage of the larynx);
• ends in the area of ​​the X-XI thoracic vertebra.

Traditionally, there are 3 sections of the esophagus:

• cervical,
• chest,
• abdominal.

Cervical region

Its boundaries:

• above – the lower edge of the cricoid cartilage (level of the VI cervical vertebra);
• below - the jugular notch of the sternum (level of the I-II thoracic vertebra).

The length of this part of the esophagus is small and is only 5-6 cm in an adult.

Heading down, the esophagus passes behind the trachea, and on either side of it are the common carotid arteries and recurrent nerves.

Thoracic region

It starts from the jugular notch of the sternum and ends at the level of the X-XI thoracic vertebra in the place where the esophagus leaves the chest cavity through the hole in the diaphragm. This is the longest part, its length is 15-18 cm.

In the chest area, the esophagus is closely surrounded by other organs:

• in front of it are the trachea, aortic arch, tracheal bifurcation, left bronchus, pericardium with the heart located in it;
• behind – the thoracic lymphatic duct, vertebral column, aorta, azygos vein;
• on the sides - mediastinal pleura, vagus nerve.

Abdominal

This is the shortest part, its length is 1-3 cm. It starts from the esophageal opening of the diaphragm and ends at the junction with the stomach. Here the esophagus comes into contact with:

• liver;
• vault of the stomach;
• often with the spleen.

Structure

There are 3 layers in the wall of the esophagus, which go from the inside to the outside as follows:

• The mucous membrane is the innermost layer, is easily renewed, has a folded structure, contains cells that produce slightly alkaline mucus, and numerous receptors that carry information to regulatory centers regarding the process of swallowing and the movement of food through the esophagus.
• The submucosal layer is quite loose; there are rich arterial, venous, nervous and lymphatic plexuses.
• The muscle layer is represented by two types of fibers, in the upper third there are striated muscles, and below there are smooth muscle fibers, also located in 2 layers. Circular fibers run almost in a spiral inside, and longitudinal fibers run outside.
• Adventitia is the outer lining of the esophagus, where nerve fibers and blood vessels of the esophagus pass.

Esophageal sphincters

Circular muscle fibers form small thickenings (sphincters), the prolonged contraction of which contributes to the normal functioning of the upper gastrointestinal tract. The most important of them are:

• upper (pharyngeal-esophageal) - protects against the throwing of food from the esophagus back into the pharynx;
• the lower one prevents.

Narrowing of the esophagus

Esophageal narrowings are divided into 2 groups:

• physiological,
• anatomical.

Anatomical narrowings are always present, but physiological ones are present only in a living person. In places of narrowing, it may be difficult for a bolus to pass through, and foreign objects accidentally swallowed by small children stop here, which can be seen on an x-ray.

The following narrowings of the esophagus are distinguished:

• pharyngeal (cricopharyngeal, cricopharyngeal) - the area formed by the cricoid cartilage and the inferior pharyngeal constrictor;
• aortic – in the area of ​​the aortic arch;
• bronchial - at the point of contact of the esophagus and the left bronchus;
• diaphragmatic - in the area where the esophagus passes through the diaphragmatic ring;
• cardiac - at the entrance of the esophagus directly into the stomach.

In this case, the cardiac and aortic are considered to be physiological narrowings, and the diaphragmatic, bronchial and pharyngeal - anatomical.

Functions of the esophagus

The main function of the esophagus is to carry food from the mouth to the stomach. Once in the lumen of the esophagus, the food bolus causes the walls of the esophagus to expand in front of itself and close behind it for 5-6 cm. The contraction of the longitudinal muscles pushes food towards the stomach. In this case, the lower sphincter opens a few seconds earlier than the food bolus reaches it. Such coordinated work occurs due to complex regulatory processes on the part of various parts of the nervous system and the action of local hormones.

Various mental factors, including stress, as well as diseases of the chest and abdominal cavity, can lead to motor dysfunction of the esophagus when they occur:

• difficulty swallowing (feeling of a lump in the throat);
• the appearance of antiperistaltic waves directed from the stomach to the pharynx, etc.

On the other hand, when the mucous membrane is irritated, reflex disorders in the functioning of other organs can occur - increased heart rate, respiratory rate, increased salivation or.

Another important function of the esophagus is to prevent the reflux of stomach contents into the airways, pharynx and oral cavity.

Anomalies in the structure of the esophagus

If for some reason the development of the esophagus is disrupted, then various anomalies of this organ may occur, which are treated primarily surgically. The most famous among them are:

• absence of the esophagus (aplasia);
• obstruction (atresia);
• doubling;
• extension;
• abnormal narrowing;
• the presence of fistulas connecting the esophagus to the trachea;
• shortened esophagus;
• the presence of stomach cells on the mucous membrane that produce hydrochloric acid and gastric juice.

How to take care of your esophagus

The habit of drinking very hot tea increases the risk of developing esophageal cancer.

To avoid causing a burn to the esophagus, do not consume any chemically active substances:

• In everyday life, burns with subsequent scarring of the mucous membrane are most often caused by banal vinegar essence, which in appearance is confused with water or vodka.
• Always keep corrosive liquids in labeled containers.
• The habit of drinking tea that is too hot increases the risk of esophageal cancer.

Try to eat food in a peaceful state. Remember that strong negative emotions and stress can lead to dysfunction of the esophagus and cause difficulty in moving the food bolus towards the stomach.

Which doctor should I contact?

If you suspect a pathology of the esophagus, you should contact a therapist or gastroenterologist. It is usually carried out less frequently, after which drug therapy is prescribed or the patient is referred to a surgeon.

Many believe that the esophagus has nothing to do with the digestion process; moreover, some do not even assume that there are diseases of the esophagus, however, until they personally encounter it. In fact, the anatomy of the esophagus and its functions are very important.

The esophagus is a narrow muscular tube approximately 25 centimeters long. It is located at the level from the sixth cervical to the eleventh thoracic vertebrae. In other words, the esophagus is a section that connects the pharynx and stomach, and accordingly is directly involved in the passage of food through the gastrointestinal tract. The esophagus has three parts, cervical, thoracic and abdominal, and also has 3 constrictions: upper, middle and lower.

Anatomy

The wall of the esophagus consists of a mucous membrane (covered with stratified epithelium), a submucosa (in which mucus-producing glands are scattered), a muscular layer (consists of an inner and outer layer) and a connective tissue membrane.

On the one hand, the structure of this organ is not so complex, but it is not so much the structure that is important as the functions that the esophagus performs.

Basic functions

The esophagus performs the following functions: motor-evacuation, ensuring the movement of food through the esophagus due to muscle contraction, peristalsis, gravity and changes in pressure. The next function is secretory - the walls of the esophagus secrete mucus, which saturates the bolus of food, as a result of which its passage into the stomach is facilitated. And, of course, we should not forget about the protective barrier function, which is carried out thanks to sphincters that prevent the reflux of stomach contents back into the esophagus, pharynx, respiratory tract, and oral cavity.

Frequent symptoms of diseases:

• belching;
• heartburn;
• disruption of food passage through the esophagus;
• pain when eating in the esophagus;
• feeling of a lump in the throat;
• vomit;
• hiccups;
• pain in the epigastric region.

Symptoms of esophageal diseases are often not expressed, but problems with the esophagus can lead to serious consequences, as a result of which you need to pay attention to even minor symptoms, and if there are any prerequisites, it is better to immediately go to the doctor for examination.

Functional disorders

At first glance, the anatomy of the esophagus is quite simple, but in reality everything is much more complicated. The structure of the esophagus has many nuances; today a large number of acquired and congenital defects have been studied. One of the most common defects is incorrect anatomy of the sphincter, which connects the esophagus to the stomach. Another common defect is narrowing of the esophagus, which makes swallowing difficult. There are also other structural disorders of the human esophagus, but we will now look at acquired diseases.

Achalasia of the human esophageal cardia

This is a chronic disease that is characterized by insufficient reflex relaxation of the esophageal sphincter or its absence, as a result of which intermittent symptoms of esophageal obstruction appear, which is caused by a narrowing of its section. The disease can develop at any age.

Symptoms of the disease

Dysphagia is the earliest and most permanent symptom, which has its own characteristics, for example, difficulty in passing food does not appear immediately, but after 2-4 seconds from the start of swallowing;
the retention of the food bolus is felt by the patient not in the throat or neck, but in the chest;
Dysphagia with achalasia cardia occurs when consuming both solid and liquid foods. In most cases, with achalasia cardia, the manifestations of esophageal dysphagia gradually intensify, although this process can last for quite a long time.

Regurgitation is the entry of undigested food back into the oral cavity, otherwise this symptom can be called regurgitation.
Chest pain occurs in 60% of people with this disease.

Weight loss – patients experience sudden weight loss.

Diagnostics:

• radiography;
• manometry;
• endoscopy - in this case, they look at what the lower part of the esophagus and stomach looks like, and what the diameter of the sphincter is.

This disease is treated with medication, but research is currently underway on the latest developments in the field of surgical intervention.

Gastroesophageal reflux disease

This disease is caused by regular spontaneous release of duodenal fluid and undigested food into the esophagus. Lifestyle, nutrition, work, the presence of stress factors, smoking, pregnancy, taking medications, and so on play a huge role in the development of this disease.

By the way, as for medications, they need to be taken carefully, since in addition to the fact that we are treating one disease, we can cause harm to other organs, which will lead to serious problems. As for an organ such as the esophagus, in this case we can damage the mucous membrane with various chemicals or analgesics. The main symptoms are heartburn and belching after eating, as well as pain at night, radiating to the shoulder blade, neck and sternum. Diagnosis of the disease includes all examination methods that allow us to identify acquired pathology of the anatomy of the human esophagus. For example, an x-ray can reveal the presence of a hernia, ulcer, erosion, and accordingly diagnose the disease. Treatment is mainly medicinal, but in particularly difficult cases they resort to surgical intervention.

Various esophagitis

This is an inflammation of the lining of the human esophagus, the most common cause of which is a burn to the esophagus or physical injury. There are acute and chronic esophagitis. Diagnosis is made using X-ray examination, esophagoscopy, monitor pH-metry, esophagomanometry. Treatment is conservative, however, in cases of unsuccessful treatment, surgical intervention is resorted to.

Diffuse spasm of the esophagus or esophagospasm

This is a spasm of the esophagus, as a result of which its diameter in some area decreases. Basic examination methods are used for diagnosis. Treatment is conservative, less often surgical.

Esophageal dyskinesia

This is a violation of the motor function of the esophagus in the absence of physical and chemical lesions.

Classification

• Impaired peristalsis of the thoracic esophagus.
• Hypermotor: diffuse esophagospasm, nonspecific motor disorders, segmental esophagospasm.
• Hypomotor: cardiospasm, gastroesophageal reflux disease, upper sphincter disorder.

Main causes

1. Primary: hysteria, chronic and acute stressful situations, hereditary developmental anomalies, age-related changes and chronic alcoholism.
2. Secondary: other gastrointestinal diseases, diseases of other systems, taking medications.

Treatment is medicinal, during treatment the patient must remain in the hospital.

Prevention of esophageal diseases

The most important thing in the prevention of esophageal diseases is proper diet and lifestyle. In the first place is a balanced diet - eating at least three times a day, with the obligatory intake of vegetables and fruits. Water regime is also important, which plays a big role in the normal functioning of the entire body as a whole.

An important point is the timely completion of preventive examinations, since the disease can be diagnosed only after an examination, and this can also be done by a person competent in this matter, that is, a gastroenterologist or family doctor.

By the way, a good prevention and incentive for regular medical examinations are photos on the Internet, which you can find on many sites, namely a photo of the esophagus affected by an ulcer, or a photo of esophageal cancer; when you see this, you will immediately run to the nearest clinic for an examination by a doctor, and also for diagnostics, if necessary, undergo treatment, even agree to surgical intervention.

By the way, if you have any of the signs and symptoms described above, you do not need to self-medicate by buying medications at the pharmacy that you learned about from your friends or on the Internet. After all, to draw up a proper recovery program, it is necessary to collect the entire medical history, as well as find out about concomitant diseases. In some cases, taking certain medications is contraindicated, and you can aggravate the situation with your self-medication. The same can be said about traditional medicine, since not all herbs are suitable for one person or another, and accordingly you can cause irreparable harm to your health.

By answering the questions below, you can determine whether you are at risk. Remember that it is never too late to check the state of your body and health in general.

• Age 45 years or more.
• Smoking more than ten cigarettes a day for several years or more.
• Overweight.
• High blood pressure.
• Heredity (presence of relatives with tumors of the gastrointestinal tract).
• Constant abdominal pain, heaviness in the stomach, heartburn, nausea.
• The presence of gastritis and stomach ulcers.
• Presence of intestinal polyps.
• Large meals and Fast Foods.

The more of the listed indicators are typical for you, the more indications for a thorough medical examination you have. Of course, it's up to you to decide, but think about the fact that prevention is much cheaper and easier than treatment. Take, for example, a car - a good car owner always does maintenance on his car on time, since repairs are much more expensive, moreover, they take much longer, and therefore it is stressful. Now imagine that your body is the same as a car, which urgently needs the prevention of various diseases, because it can also fail, but most often with more severe consequences.

“I approve” Department of Hospital

Head Department of Surgery, State Educational Institution of Higher Professional Education

Professor Cherkasov V.A. PSMA named after. ak. E.A. Wagner

Roszdrav

METHODOLOGICAL DEVELOPMENT

TOPIC OF THE LESSON: Diseases of the esophagus.

OBJECTIVE OF THE LESSON: To study the etiopathogenesis, clinical picture, methods of diagnosis and treatment of diseases of the esophagus.

CLASS DURATION: 4 hours.

LOCATION: Wards, dressing room, operating room, training room.

CLASS EQUIPMENT: Set of slides, radiographs, tables, tools.

METHODOLOGICAL ADVICE FOR PREPARING FOR THE CLASS.

Anatomy of the esophagus.

The length of the esophagus in women is within 23-24 cm, and in men within 25-30 cm (Tonkov V.N., 1962). It is currently believed that the length of the esophagus in an adult is on average 25 cm.

Most authors topographically distinguish 3 sections of the esophagus: cervical, thoracic and abdominal. The cervical spine begins at level CVI and ends at level ThII. This rather short section of the esophagus (5-6 cm) is completely covered with a layer of loose connective tissue, which passes into the fiber of the upper mediastinum, which makes it quite mobile and pliable when swallowing. 2/3-3/4 of foreign bodies get stuck in this section. The anterior surface of this section is adjacent to the trachea and the left lobe of the thyroid gland, the posterior surface is adjacent to the spinal column (CVI - ThII), and the lateral surface is adjacent to the thyroid gland, carotid arteries, and recurrent nerves.

The thoracic esophagus begins at the upper border of the posterior mediastinum (ThII) and ends at the entrance to the esophageal opening of the diaphragm at the level of ThIX-X. This longest section of the esophagus (16-18 cm) is closely adjacent to the mediastinal pleura and is separated from the vertebral fascia by a thin layer of loose fiber. From ThII to ThIV-V, the esophagus lies to the left of the trachea, at the ThIII level it intersects with the aortic arch, at the ThIV level with the azygos vein. At the height ThV, the esophagus is quite closely adjacent to the left main bronchus and the tracheal bifurcation. To the left of the esophagus at this level passes the thoracic lymphatic duct, recurrent nerve, aortic arch or subclavian artery. At the level of the bifurcation, the posterior wall of the left atrium, separated by the pericardium, adjoins the esophagus in front. 2-3 cm above the diaphragm near the surface of the left ventricle, the esophagus deviates to the left at an angle. Along the entire thoracic region, the mediastinal, paravertebral, para-aortic and especially tracheobronchial and bifurcation lymph nodes are closely adjacent to the esophagus. Such close proximity to all organs of the mediastinum must be taken into account in case of diseases and injuries of the esophagus.

The diaphragmatic section of the esophagus, the shortest (1.5-2.5 cm), is located at the level of the esophageal opening and extremely rarely - at the level of the common aortic-esophageal opening, normally at the level of ThIX-X, 2-3 cm in front of the spinal column and 1 cm to the left midline of the body. The fibromuscular ring, involved in the opening of the cardia, ensures its tightness, and the rather loose fiber inside the diaphragm provides the esophagus with mobility in the longitudinal direction. This functionally important section of the esophagus, which does not have a lumen at rest, was called epicardia by M. Brombart (1956).

The subphrenic, or abdominal, section of the esophagus, called in the literature the vestibule of the cardia, has an average length of 3-4 cm (1-7 cm). This section, between the dome of the diaphragm and the anatomical cardia, is adjacent to the posterior surface of the left lobe of the liver and is covered in front and on the sides by the peritoneum. The diaphragmatic and abdominal sections of the esophagus are functionally the same and, according to most authors, are the physiological cardia.

The outer lower border of the cardia is usually considered to be the acute angle of entry of the esophagus into the stomach, the angle of His, formed by the end of the first year of life. It represents the angle of transition of one side wall of the esophagus into the greater curvature of the stomach, while the other side wall smoothly passes into the lesser curvature.

It is assumed that functionally this place prevents regurgitation. Its effectiveness directly depends on the sharpness of the His angle. The inner lower border is usually recognized as a fold of the mucous membrane (plicacardiaca). The air bubble of the stomach and intragastric pressure contribute to the tight fit of the mucosal valve to the right wall, thereby preventing the reflux of stomach contents into the esophagus.

Currently, the existence of 4 physiological narrowings of the esophagus (a decrease in diameter by more than 1/3) is recognized. In places of narrowing, foreign bodies are more often retained, injuries, esophagitis, scars and neoplasms occur. Skeletotopically, the narrowings are located at the level of CVI (first), ThIII (second, aortic), ThV (third, bronchial), ThX (fourth, legs of the diaphragm).

In clinical practice, a conventional division of the esophagus into segments is accepted (M. Bromart, 1956):

tracheal(supraphrenic) 8-9 cm long from the mouth of the esophagus to the aortic arch;

aortic– 2.5-3 cm long, corresponds to the diameter of the aortic arch;

bronchial segment– located at the level of the tracheal bifurcation; destruction of this segment by a tumor of the left bronchus or central lung cancer leads to bronchoesophageal fistulas;

aortic-bronchial segment– between the lower edge of the aortic arch and the upper edge of the left main bronchus; pulsion diverticula often occur here;

suprabronchial segment 4-5 cm long, from the bifurcation to the left atrium; damage to the bifurcation lymph nodes often leads to the development of traction diverticula of the esophagus;

retropericardial segment, adjacent to the wall of the left atrium in front, and to the descending aorta behind; in this segment, functional disorders of the esophagus (dyskinesia) appear more often than in others;

supradiaphragmatic segment 3-4 cm long; in this segment one can observe epiphrenic diverticula, varicose veins, terminal reflux esophagitis, hernias, peptic ulcers and strictures;

intradiaphragmatic segment has an average length of about 2 cm; the pathology of this important part of the esophagus leads to the formation of congenital and acquired hiatal hernias, reflux esophagitis, ulcers and strictures, achalasia, tumors and other organic damage; in addition, many types of dysfunction are caused by a disorder of this segment;

abdominal segment 3-4 cm long, called the vestibule, or physiological cardia. This segment, together with the diaphragmatic and cardia, constitute a single mechanism for regulating the cardia.

Vascularization of the esophagus, compared to other parts of the digestive tract, is less pronounced due to the absence of a single esophageal artery. The cervical esophagus is supplied by branches of the inferior thyroid artery and partly the left subclavian artery. The thoracic region is vascularized by the branches of the bronchial and intercostal arteries and the thoracic aorta. The abdominal region, covered with peritoneum, is better supplied with blood than others, receiving nutrition from the inferior phrenic and left gastric arteries. The intramural vasculature is most developed in the submucosa, in which the arterial plexus supplies the mucosa and muscularis. The blood flows through the venules into the venous plexus, which is quite complex in structure, the main collector of which is the central submucosal plexus, which lies next to the arterial plexus. The main venous lines in the cervical region are the thyroid and bronchial ones, in the thoracic region - paired and unpaired, i.e. the system of the superior vena cava, in the abdominal - the veins of the stomach and liver, i.e. portal vein system. Thus, the veins of the thoracic and abdominal sections create a portacaval anastomosis, which is important in clinical practice.

The lymphatic system of the esophagus is characterized by a longitudinal orientation, i.e. the outflow of lymph either upwards, towards the pharynx or downwards, towards the stomach. In this regard, metastases from gastric cancer first spread intramurally and only later are detected in regional lymph nodes. Typically, lymph from the cervical esophagus is directed to regional nodes near the trachea (paratracheal nodes) or along the jugular vein. Lymph from the middle third of the esophagus flows into the mediastinal, bifurcation and tracheobronchial lymph nodes. From the lower part of the esophagus, lymph is directed along the organ, so with cancer of this part of the esophagus, cardia or upper stomach, metastasis to the supraclavicular lymph nodes is possible. The common development of the esophagus and stomach is confirmed by the outflow of lymph from the lower segments of the esophagus to the lymph nodes of the upper stomach and the frequent development of cardioesophageal cancer.

The innervation of the esophagus is complex and unique. Parasympathetic innervation occurs through the vagus and recurrent nerves, sympathetic innervation through the nodes of the border and aortic plexuses, branches of the pulmonary and cardiac plexuses, solar plexus fibers and subcardial ganglia. Numerous nerve branches form the superficial anterior and posterior plexuses of the esophagus. The anterior one is formed mainly by fibers of the right vagus nerve, the posterior one - by the left one. The intramural nervous apparatus consists of three closely interconnected plexuses - adventitial, intermuscular and submucosal. They contain peculiar ganglion cells (Dogel cells), which determine autonomous internal innervation and local regulation of the motor function of the esophagus. The vagus nerves are connected by their pulpal fibers to the intramural plexuses, and the non-pulmonary nerves are connected to other intramural plexuses. Some of the non-pulp fibers end on muscle cells. Thus, the esophagus, like the heart, has its own autonomous nervous system. Reflex self-regulation is carried out mainly by the intramural plexuses.

The cervical part of the esophagus is innervated by the recurrent nerve, the thoracic part by the branches of the vagus and sympathetic nerves, and the lower celiac nerve. The fibers of the recurrent nerve innervate the striated muscles, and the sympathetic nerve innervates the smooth muscles of the esophagus. Efferent nerve fibers, in addition to muscles, innervate the glands of the esophagus, and afferent fibers (ThV-VII) provide sensory innervation. The mucous membrane is sensitive to thermal, painful and tactile stimuli, with the distal segments and cardia being the most susceptible. The area of ​​the mouth of the esophagus and places of physiological narrowing are most sensitive to mechanical irritation. Sensory innervation is carried out by the vagus nerve, the main regulator of esophageal motility. The sympathetic nervous system controls the tone of the esophagus. Thus, the esophagus and cardia contain their own intramural neuromuscular apparatus, regulated by the central and autonomic nervous systems.

To know the relationship between the trachea and the esophagus, it is necessary to become familiar with the structure of these organs, their location and functions.

When a person swallows, his breathing is blocked for a second.

If a piece of food is stuck in the larynx, the person suffocates.

The proper distribution of air masses and food in the throat is carried out in connection with the existing complex system of valves, which in turn block the passages.

Mechanism of action

For a long time, in a calm state of the muscles that are responsible for swallowing, the air channel from the pharynx to the throat is open, and a person can inhale oxygen with minimal effort.

At this time, the septum between the oral cavity and the nasopharynx (soft palate) is in a state during which a passage into the oropharynx and nasal cavity opens for air.

Thanks to this, it is possible to effortlessly control the position of the palate, lowering it and cutting off the supply of oxygen to the oropharynx. However, during the same period it is not possible to fully lift it; the lumen will remain open.

This is the case when a cough begins during a meal and some of the food enters the nose from the esophagus.

Below the larynx is the trachea, the pathway through which oxygen passes from the throat into the lungs.

At the base of the organ in question there is a small valve, called the epiglottis, which completely closes the entrance during its descent.

For a long period, the epiglottis is elevated, and therefore the outlet to the windpipe is open for air supply.

This mechanism is similar to a hatch with an open lid, which protects it from the penetration of various foreign objects during the process of swallowing food products.

During this period, the epiglottis will close partly with muscles, and partly under the influence of food.

A person himself is able to lower and raise the epiglottis, carrying out swallowing movements.

This is done directly when there is a need to stop breathing. Then everything will return to its previous state.

Structure and functions of the esophagus

The esophagus is a hollow organ that looks like a narrowed and movable tube up to 30 cm long, connecting the larynx and stomach.

The rudiments of the esophagus appear already in the 1st month of embryo formation, and by birth it is practically formed, the diameter of its gap is up to 0.8 cm, and its length is up to 15 cm.

Location

Experts distinguish between the beginning and end of the esophagus and correlate it with visible and permanent bone formations in the skeleton:

• starts from the 6th cervical vertebra;
• ends near the 10-11 thoracic vertebra.

It is customary to distinguish 3 departments of the organ in question:

• Cervical. Above is the lower part of the cricoid cartilage, below is the jugular notch of the sternum. The length of this section is small and is approximately 50 mm in adulthood. Descending downwards, the esophagus bypasses the windpipe, and from the sides there are the carotid arteries and recurrent nerves.
• Chest. It departs from the jugular notch and ends approximately near the 10-11 thoracic vertebrae in the area where the esophagus exits the sternum cavity through the lumen in the diaphragm. The longest section of the organ in question. It is closely interconnected with the rest of the organs of the chest: the trachea, aorta, left bronchus, pericardium with the heart are located in front of it; behind it is the thoracic lymphatic tract, spine, azygos vein; on the side – pleura, vagus nerve.
• Abdominal. It is the shortest section, approximately 20 mm long. It begins from the lumen of the diaphragm, and ends at the point of transition into the stomach.

Structure

In the wall of the organ in question there are several layers extending outward:

• Mucous. The deepest layer is rapidly renewed, has a folded structure, and includes cells that produce slightly alkaline mucus, as well as multiple receptors. They carry information to regulatory centers regarding the ingestion and movement of food products along the esophagus.
• Submucosa. An extremely loose layer where the arterial, venous, nervous and lymphatic plexuses are concentrated.
• Muscular. It is expressed by 2 types of fibers, striated muscles are located at the top, and smooth muscle fibers are located below, which consist of 2 layers. Circular fibers are located almost in a spiral inside, and longitudinal fibers are located on the outside.
• Adventitia. The outer lining of the esophagus, where the nerve endings and blood vessels go.

Anatomical features

The anatomical structure of the esophagus and its functional development has a number of characteristic features that affect its corresponding activity.

We are talking about the supply of blood to the organ in question, carried out in the neck from the thyroid arteries, in the chest - thanks to its own arteries.

The lymphatic system is essentially a network of capillaries and vessels with which the walls of the organ in question are dotted.

A characteristic feature of the blood flow system will be the collector vessels located inside the esophagus. They are designed to connect all lymphatic networks.

An important aspect will be the lymphatic topography, demonstrating the direction of the vessels from the neck to the lower cervical lymph nodes. Bypassing adjacent nodes, it penetrates the thoracic lymphatic duct.

Functions of the esophagus

The main purpose of the esophagus is to move food from the mouth deep into the stomach.

Getting into the lumen, a lump of food provokes an increase in the walls of the organ in question in front of it and closure behind it. Muscle contraction helps push food into the stomach.

In addition, the lower sphincter opens 5-7 seconds earlier than food reaches it.

Such well-functioning work is possible only thanks to complex regulatory processes in various parts of the central nervous system and the influence of local hormones.

A variety of psycho-emotional factors, including stressful situations, pathological processes in the organs of the chest and abdomen, can provoke motor disorders in the functioning of the esophagus, resulting from:

• difficulty swallowing (feeling of a lump in the larynx);
• the occurrence of antiperistaltic waves that are directed from the stomach deep into the larynx, etc.

In addition, during the period of irritation of the mucous membrane, reflex disturbances occur in the functioning of other organs - rapid heartbeat, rapid breathing, increased tearing or salivation.

The second important function is to prevent the occurrence of reflux (food is thrown into the respiratory tract, larynx and oral cavity).

Anomalies in the structure of the esophagus

When, due to some circumstances, a disruption in the functioning of the esophagus occurs, various deviations appear, which are eliminated mainly by surgical methods.

The most common anomalies are:

• the organ itself is missing;
• obstruction;
• the esophagus can be doubled, expanded, narrowed;
• the presence of fistulas that connect the organ in question to the windpipe;
• the esophagus may be shortened;
• the presence of cells on the gastric mucosa that produce hydrochloric acid and pancreatic juice.

Clinical anatomy of the trachea and esophagus

The trachea is an empty tube shaped like a cylinder, considered the end of the larynx.

It originates approximately near the 7th vertebra of the neck and passes to 4-5 vertebrae of the thoracic region, where it ends with a bifurcation into 2 main bronchi.

The degree of branching is greater in people at a young age. The length of the organ in question will be approximately 11-12 cm.

The wall contains 16-20 cartilages that resemble a horseshoe. The arc is directed forward, and the back part is connected by a special membrane - the membranous wall.

This membrane has collagen fibers, and in the lower part there are longitudinal-transverse muscle fibers. The width varies in the range of 1-2 cm.

The cartilages are interconnected with each other by annular ligaments. The internal surface of the organ in question is lined with mucous membrane.

In the submucosa there are mixed glands designed to produce mucous secretion. A crescent-shaped bulge forms inside the trachea.

The right bronchus will be wider, extending from the windpipe at an angle of 15 degrees, its length is 3 cm.

The left one is at an angle of 45 degrees, up to 5 cm in length. From here we can conclude that the right one is actually considered a continuation of the organ in question, which is why foreign objects often penetrate inside it.

Tracheal topography

In the upper part, the trachea is attached to the cricoid cartilage by a special ligament.

In the neck area, the isthmus of the thyroid gland is adjacent to the near surface of the organ in question, and the lobes are adjacent to the lateral side. Posteriorly, the trachea is in close proximity to the esophagus.

On the right side of it is the brachiocephalic trunk, on the left is the common carotid artery.

Clinical physiology

The larynx and trachea perform the following functions:

• Respiratory. Oxygen passes through the throat into the lower respiratory tract. The glottis will expand during inhalation, and its size will vary depending on the needs of the body. During a deep breath, it will expand more, and the bifurcation of the windpipe will often become noticeable. The opening of the gap is carried out reflexively. The inhaled air is capable of irritating multiple nerve fibers in the mucosa, from which the impulse passes along the afferent endings of the upper laryngeal nerve and is sent through the vagus to the respiratory center. From here, motor signals pass along the efferent processes to the muscles that expand the glottis. Under the influence of such irritation, the functioning of other muscles is enhanced.
• Protective. It is interconnected with the presence of 3 reflexogenic zones of the throat mucosa: 1 is located in the immediate vicinity of the entrance to the throat; 2 - vocal folds; 3 is located in the internal cricoid cartilage. The receptors that are embedded in these areas are characterized by all types of susceptibility - tactile, temperature, chemical. In the process of irritation of the mucous membrane of these areas, spasm of the glottis occurs, and therefore the lower part of the respiratory tract is protected from the penetration of saliva, food products and foreign objects. The key manifestation of this function will be a reflex cough. It causes the release of foreign objects that enter the respiratory tract with air.
• Voice-forming. Plays an important social role in human activity, since it directly takes part in the reproduction of speech.

The production of sounds and speech production involves every part of the respiratory tract:

• lungs, bronchi and trachea;
• vocal apparatus of the throat;
• the oral cavity, nasopharynx and paranasal sinuses, where sound resonates.

With the help of these forces, after stretching, a return phase occurs and the gap closes again. Then the cycle will be repeated, at which time the air stream vibrates over the vocal folds and themselves. They carry out amplitudes in a given direction, inward and outward perpendicular to the air flow.

In the process of pronouncing a sound of a certain frequency, a person contracts the muscles of the larynx in some way and adds the required length and specific shape to the folds.

The pattern of fold amplitudes is similar to the vibrations of a steel plate in the shape of a ruler, with a clamped and free end. When deflected, one of them will create vibration and make sounds.

In the throat there is a similar pattern, with the only difference being that the force that causes the vibrations is applied over a long period of time.

This is referred to as natural sound production - the chest register. During the pronunciation of a sound, it is possible to feel the vibration of the front wall of the chest with your hand.

During whispering, the folds do not close along the entire length, but only in the anterior two-thirds. There will be a triangular gap at the back through which oxygen will pass, creating noises called whispers.

Sound has its own characteristics. In addition, it has differences in pitch, timbre and intensity.

The height is interconnected with the number of fluctuations of the folds, and that with the length. As you grow older, the dimensions of the folds change, which provokes certain changes.

The oral and nasal cavities, acting as an upper resonator, help to enhance certain overtones of the sound of the larynx, so it will have a distinctive timbre.

By changing the location of the cheeks, tongue, lips, it is possible to independently change the sound characteristics, but only within acceptable limits.

The properties of timbre are individual for all people, depending on gender and age.

In addition, it has exceptional individual differences, which makes it possible to recognize people by their voice.

The trachea and esophagus are inextricably interconnected with each other, due to their structure, functioning and position.

The anatomical role of the esophagus is to accompany food products into the stomach.

In the oropharynx, the lump is initially crushed and enveloped in saliva. The tongue moves the finished mass towards the organ in question, which provokes swallowing.

At this stage, the throat will rise to the top. The exit to the pharynx is closed by the epiglottis, as a result of which the return of food masses back into the oropharynx is prevented by the raised tongue.

Their further passage is carried out thanks to peristalsis: the section of the esophagus located in the immediate vicinity above the food bolus will contract, and the lower part will relax. The lump seems to be pressed deep into the esophagus.

Such movement through the organ in question into the stomach will take several seconds.

Useful video

What is the esophagus? This is a tube-shaped channel. It refers to the hollow organs of the human digestive system. It is presented in the form of a cylindrical tube 25 cm long.

On one side it borders on the pharynx, on the other on the stomach. Some structural features are weak areas and contribute to the development of other parts of the gastrointestinal tract.

It originates at the level between the 6th and 7th vertebrae of the neck. This border is the line of transition of the pharynx into the esophagus. It ends at the level of the 11th thoracic vertebra, where it passes into the stomach. In a quiet position, the lumen has a slit-like shape. What is the structure of the human esophagus? The following parts of the esophagus are distinguished in structure:

These are the sections of the human esophagus. The cervical part is close to the spinal column. But at the level of the 4th vertebra, the esophagus passes behind the aorta, namely its arch. Then the location of the organ between the 4th and 5th vertebrae changes. Here the esophagus crosses with the left main bronchus. At the same time, it bends around part of the aorta.

But at the level of the 9th thoracic vertebra, it is located in front of the aorta.

The third part is the shortest. It is about 2 cm. It is already located directly under the diaphragm. The esophagus is connected to the diagram by bundles of connective tissue. The opening for this organ itself is limited by the legs. During inhalation, these legs of the diagram contract and the part of the esophagus that runs there closes. This area is where hiatal hernias form. Due to the weakness of the legs and ligaments connecting the esophagus and diaphragm.

The abdominal part is divided into two edges. The right one goes into the lesser curvature of the stomach. The left one, in turn, forms a certain depression with the bottom of the stomach. They call it differently Angle of His.

In addition, it has, accordingly, three narrowings. They are called physiological. The first is located between the 6th and 7th cervical vertebrae. The second is located on the line of decussation with the main bronchus on the left. And the third is at the site of the esophageal opening in the diaphragm. Accordingly, the first is called pharyngoesophageal, the second is bronchoaortic, and the third is diaphragmatic. Foreign bodies, such as fish bones, can get stuck in these constrictions. These places are also often .

When examining a person, only two narrowings are revealed. These include aortic And cardiac. The first is called so due to the adhesion of the aorta. The second is due to the corresponding transition of the esophagus to the stomach area at the level of the 11th thoracic vertebra. The junction is called the esophagogastric sphincter.

The entire esophagus is shrouded in loose tissue. Thanks to this, he is quite mobile. But in the neck area it is tightly adjacent to the trachea. The question of the location of the esophagus is now all clear. And where the human esophagus is located can be easily seen in the photos and diagrams above.

Wall structure

If you examine the human esophagus under a microscope, the structure of its wall consists of 4 layers. There are:

The esophageal mucosa itself is formed due to such a component as multilayered squamous non-keratinizing epithelium of the esophagus. It is presented in the form of flat cells that do not keratinize. It contains its own lamina mucosa. It is quite well expressed. It contains the cardiac and esophageal glands.

Their structure is very similar to those in the stomach. There are folds in a longitudinal direction. The muscle layer towards the stomach tends to thicken. It is expressed differently in different parts. In the upper section, the muscle layer is formed by striated muscles. In the middle part they are gradually replaced by smooth myocytes. And closer to the stomach in the muscle layer there is only smooth muscle.

In general, there are two options for the location of muscle cells. In the esophagus it is circular and transverse. This structure and location of the muscle layer contributes to the rapid movement of the food bolus into the stomach.

Adventitia It is most pronounced in the area above the diaphragm. The abdominal part is covered with peritoneum completely or in parts.

Of particular importance is the location of the transition from the esophagus to the stomach. Due to the junction of different types of epithelium, if there is reflux, can develop metaplasia. That is, the epithelium will gradually change. This condition is a condition for the development of cancer.

Curves of the esophagus

Along its course, this organ forms certain bends. That is, areas where it changes its direction in some sense. Initially, it is located along the median lines or in the middle. Then a slight bend forms at the level of the 6th cervical vertebra. It is carried out anteriorly.

Reaching 2 And 3 thoracic vertebrae the esophagus moves to the right. This portion of the bend is called anteroposterior. It corresponds to the physiological curvature of the spinal column. After the 2nd chest, another bend is formed. In this case it goes forward. This is due to its proximity to the aorta. When it passes through the diaphragm ring, an anterior displacement occurs.

Due to its mobility, the esophagus can slightly change its bends. This feature allows surgeons to perform operations on various pathologies.

What organs is the esophagus adjacent to?

The relative position of organs near the esophagus determines their involvement in the pathological process in the latter. Since the structure is divided into three parts, the location of various organs and neurovascular bundles should be considered in the same way.

The cervical part is about 7 cm in length. The trachea is located in this area in front. The right and left recurrent nerves pass along the surfaces. With a tumor of the esophagus, the left recurrent nerve may be compressed, which will manifest as hoarseness. On the side there is a neurovascular bundle.

The thoracic part is about 16 cm in length. The sequence from top to bottom in this part of the esophagus is adjacent:

• tracheal wall;
• aortic arch;
• left main bronchus.

Going lower, it passes behind the heart, namely the pericardium. Due to anatomical features, the organ may be located too close to the pericardium. If there is pericarditis, then inward protrusions will form in the hollow organ. This leads to difficulty swallowing. With pathology of the esophagus, the pericardium may also be involved. In this case, chest pain occurs.

It also borders the lymphatic thoracic duct and the aorta. The location with the aorta has a number of features. Initially, this large vessel comes into contact with the left side of the esophagus. Then she goes between him and the spine. And in the lower sections, the thoracic part already goes in front of the vessel. This relationship can lead to various consequences. For example, a tumor in the esophageal zone, when actively growing, can grow into the aorta.

The vagus nerves are located on the lateral sides of the thoracic region. With pathology of the organ, the latter can be compressed. This leads to various symptoms in the form of pain. Its localization may vary.

In some areas along the esophagus, the pleura is closely adjacent to it. This makes it difficult to carry out various operations. As a result, inflammation from the esophageal area can spread to the pleura. In this case, there will be complaints of chest pain or so-called chest pain. They are due to the fact that nerve endings are located in the pleura.

Moving into the abdominal cavity, interaction occurs with the left leg of the diaphragm, namely its lumbar part. And on the other side it borders on the liver, and specifically on the caudate lobe.

Segments and features of blood supply

Depending on which organs it is located next to, different segments are distinguished. In practice, 9 segments are distinguished. Accordingly, supra-aortic and aortic indicate its proximity to the aorta. Due to the intersection with the bronchus, they are divided into bronchial and subbronchial. When the esophagus borders both the aorta and bronchus, we speak of an interaortobronchial segment.

The section of passage past the pericardium is called retropericardial. At the border with the diaphragm, 3 segments are distinguished. These are respectively above, inside and subdiaphragmatic.

Blood supply to the esophagus occurs through the esophageal arteries. They arise from the thyroid artery, thoracic aorta and gastric branch. Venous blood flows into the thyroid, gastric, paired and semi-gyzygos veins.

The lymphatic system partially goes through the vessels into the lymph nodes, and the second half, bypassing them, enters directly into the thoracic duct.

The organ is innervated by the vagus, glossopharyngeal and branches of the sympathetic trunk. When the sympathetic trunk is compressed, dilation of the pupil is observed.

Functions of the esophagus

The first function is the evacuation of the food bolus into the stomach. It is carried out by contracting the muscle layer, which, as mentioned above, consists of two layers. When food hits the root of the tongue, the swallowing reflex is triggered. Thanks to it, the esophagus is pulled towards the lump of food and the pharyngeal-esophageal sphincter opens. At the same time, the entrance to the larynx closes.

Further, thanks to peristalsis, the food moves forward. By analogy, the sphincter between the esophagus and stomach relaxes. Food goes to the latter. Liquids and very soft foods can enter the stomach without the active participation of the esophagus. Due to the longitudinal folds on the surface, the liquid moves along them simply and without difficulty.

There is a peculiarity in the lower part and the cardia region. The esophagogastric sphincter makes movements regardless of the contractions of neighboring organs. That is, he relaxes at the moment of swallowing food.

When passing into the stomach, the esophagogastric sphincter is formed. It protects the esophageal mucosa from aggression from hydrochloric acid. That is, it acts as a barrier. Its activity is controlled by the central nervous system, independent nerve plexuses of the esophagus and humoral factors (hormones).

If it fails, a disease such as . In this case, acid is thrown back from the stomach into the esophageal region. Heartburn occurs and scar tissue gradually forms.

The secretory function is carried out due to the location of the cardiac glands in the wall. At the moment the food bolus passes, it is saturated with mucus, which facilitates its further digestion.

Useful video

For many readers, the issue of both the physiology and anatomy of the esophagus is relevant. We all know that in humans the stomach is located behind the esophagus. Some more interesting information, namely on the topic “topography of the esophagus” is presented in this video.

Variation with age (children)

In a newborn, the esophagus is shorter. It is about 10 or 15 cm. Presented in the form of a tube. And the diameter in newborns is about 4 mm. Moreover, all anatomical narrowings of the esophagus are very weakly expressed. They are fully formed only by 3 years. During the growth and development of the body, the esophageal zone also changes. By the age of 10, the organ lengthens in size. Makes up 20 cm.

The distance to the gastric cardia increases with age. In newborns it is 22 cm, and 12 years old 24 cm. Changes also occur with the lumen. If in the first years of life it is 1 cm, then as it grows by the age of 6 it reaches 2 cm.

The location of the organ is of particular importance in age-related changes. In newborns, the esophagus begins higher than in adults. At the level of the 3rd and 6th cervical vertebrae, then descends. In older people, the esophagus begins at the border of the 1st thoracic vertebra. This is the age-related characteristics of the esophagus.

Interestingly, longitudinal folds fully appear only by 3 years of age.