Esophagus in endoscopic image

The esophagus is a tube going from the pharynx to the stomach. The length of the esophagus depends on the sex, age, position of the head (when it is bent, it shortens, and when it extends, it lengthens), and averages 23-24 cm in women and 25-26 cm in men. It begins at the level of the sixth cervical vertebra, ends at the level of the XI thoracic vertebra.

Esophagus consists of 4 departments:

1. Cervical.
2. Thoracic.
3. Diaphragmatic.
4. Abdominal.

Cervical department. It goes from VI cervical to II thoracic on call. The entrance to the esophagus depends on the position of the head: at flexion - at the level of VII cervical vertebra, at extension - at the level of V-VI. This is important when detecting foreign bodies. The inner upper border of the esophagus is a labial fold, which is formed by a hypertrophied muscle (periosteal-pharyngeal). When inhaled, this muscle contracts and closes the entrance to the esophagus, preventing the aerophagy. The length of the cervical region of the esophagus is 5-6 cm. In elderly people, it is shortened due to the larynx of the larynx. In this department of the esophagus it is delayed from 2/3 to 3/4 of all foreign bodies. Outside the esophagus in this department is covered with loose fiber, which provides him with high mobility. This fiber passes into the upper mediastinum - with damage to the esophagus, air enters the upper mediastinum. Behind the esophagus in this department is to the spine, in front - to the trachea, from the sides are recurrent nerves and thyroid gland.

Thoracic department. It goes from the II thoracic vertebra to the esophageal opening of the diaphragm (IX thoracic vertebra). It is the longest department: 16-18 cm. Outside it is covered with a thin layer of fiber and fixed to the vertebral fascia. At the level V of the thoracic vertebra, the left main bronchus or the tracheal bifurcation region is attached to the esophagus. In this area, congenital and acquired tracheo-esophagic fistulas often occur. On the sides of the esophagus there are large parasophageal and bifurcation lymph nodes. When they are enlarged, impressions of the esophagus are visible.

Diaphragmatic department. Most important in a functional sense. Its length is 1.5-2.0 cm. It is located at the level of the esophageal aperture of the diaphragm. At this level, the intrinsic adventitia of the esophagus is closely related to the diaphragmatic ligaments. Here, esophageal-diaphragmatic membranes are formed that play a role in the formation of hiatal hernias

Abdominal department. The most variable: from 1 to 6 cm. It goes from the esophageal opening of the diaphragm to the XI thoracic vertebra. With age, this department lengthens. Outside is covered with loose fiber, which provides greater mobility in the longitudinal direction. The internal and lower border of the esophagus is the cardial fold.

In addition to the three anatomical constrictions, four physiological constrictions are distinguished in the esophagus:

1. The mouth of the esophagus (VI cervical vertebra).
2. In the area of intersection with the arch of the aorta (III-IV thoracic vertebra) - less pronounced. Frequent localization of post-burn scars, as well as foreign bodies, is explained not only by the presence of aortic narrowing of the esophagus, but also by the lateral bend of the esophagus over it.
3. In the area of tracheal bifurcation (V-VI thoracic vertebra) and intersection with the left main bronchus, where the latter is pressed somewhat into the esophagus.
4. In the area of the esophageal opening of the diaphragm (IX-X thoracic vertebra).

Distance from the incisors of the upper jaw to the narrowing:

1. 16-20 cm.
2. 23 cm.
3. 26 cm.
4. 36-37 cm.

The distance from the incisors of the upper jaw to the cardia is 40 cm. The diameter of the esophagus in the cervical region is 1.8-2.0 cm, in the thoracic and ventral regions is 2.1-2.5 cm. The diameter of the esophagus increases with inspiration and decreases with exhalation.

The wall of the esophagus consists of 4 layers:

• Mucous membrane:
  • epithelium,
  • own plate of the mucosa,
  • muscular plate of the mucous membrane.
• Submucoid layer.
• Muscular layer.
  • a circular muscle layer,
  • longitudinal muscular layer.
• Advent.

The epithelium is multilayered, flat, neorogovevayuschy. Mucous in the norm of light pink color with a gentle vascular pattern. In the field of cardia, the multilayered flat epithelium of the esophagus passes into the cylindrical epithelium of the stomach, forming a serrated line. This is important in the diagnosis of esophagitis and esophageal cancer, in which the clearness of the line is lost, with the cancer there may be edema of the edges. Can be up to 24 layers of epithelium. The mucosa of the cervical and abdominal parts of the esophagus are the upper and lower cardiac glands. In the abdominal part of the esophagus there are 5 times more of them than in the stomach. They contain endocrine glands secreting intestinal hormones: gastrin, secretin, somatostatin, vasopressin. Gastrin and secretin are involved in motor and trophic digestive tract. The glands are located in the lamina propria of the mucosa. The muscular plate of the mucosa consists of smooth muscle fibers.

The submucosa is formed by a loose connective tissue, on the strength of which the size of the folds depends.

The muscular membrane consists of 2 types of fibers:

1. Transversely striped - located mainly in the upper 1/3 of the esophagus, in the middle 1/3 they pass into the smooth ones.
2. Smooth muscle fibers - the lower 1/3 of the esophagus consists exclusively of them.

The muscular membrane consists of two layers - the inner circular and the outer longitudinal. The circular layer, located all over, is thinner in the initial part of the esophagus; gradually thickening, it reaches maximum dimensions near the diaphragm. The layer of longitudinal muscle fibers is thinned at the site of the esophagus, located behind the trachea, and in the terminal parts of the esophagus it thickens. In general, the muscular membrane of the esophagus in the initial section, especially in the pharynx, is relatively thin; gradually it thickens towards the ventral part. Both layers of muscle are separated by a connective tissue, in which the nerve plexuses lie.

Adventism is a loose connective tissue surrounding the esophagus from the outside. It is well expressed over the diaphragm and in the place of passage of the esophagus into the stomach.

The blood supply to the esophagus is less developed than in the stomach; there is no single esophageal artery. Different departments of the esophagus are supplied with blood in different ways.

• Neck: lower thyroid, pharyngeal and subclavian arteries.
• Thoracic: branches of subclavian, lower thyroid, bronchial, intercostal arteries, thoracic aorta.
• Abdomen: from the left lower diaphragmatic and left gastric arteries.

Venous outflow is carried out through the veins corresponding to the esophagus supplying the arteries.

• Neck: in the veins of the thyroid gland and in the nameless and upper vena cava.
• Thoracic: along the esophagus and intercostal branches in the unpaired and semi-unpaired veins and, consequently, in the upper vena cava. From the lower third of the thoracic part of the esophagus, venous blood along the branches of the left gastric vein, the upper branches of the splenic vein, is sent to the portal system. Part of the venous blood from this part of the esophagus, the left lower diaphragmatic vein, leads into the system of the inferior vena cava.
• Ventral section: in the inflow of the portal vein. In the abdominal and in the cardioesophageal junction there is a porto-caval anastomosis, which first of all expands with cirrhosis of the liver.

The lymphatic system is formed by two groups of lymphatic vessels - the main network in the submucosal layer and the network in the muscular layer, which partially connects to the submucosal network. In the submucosal layer, the lymphatic vessels go both in the direction of the nearest regional lymph nodes and longitudinally along the esophagus. In this case, the lymph drainage in the longitudinal lymph vessels in the upper 2/3 of the esophagus occurs upward, and in the lower third of the esophagus - down. This explains the metastasis not only in the immediate, but also in the distant lymph nodes. From the muscle network, the lymphatic drain goes to the nearest regional lymph nodes.

Innervation of the esophagus.

Parasympathetic:

• nervus vagus,
• reflex nerve.

Sympathetic: nodes of the borderline, aortic, cardiac plexus, ganglia in the subcardia.

The esophagus has its own innervation - the intramural nervous system, which is represented by the cells of Doppler and consists of three closely related plexuses:

• adventitious,
• intermuscular,
• submucosal.

They determine the internal autonomy of the innervation and the local innervation of the motor function of the esophagus. Esophagus is also regulated by the CNS.

Cardia. This is the place of passage of the esophagus into the stomach, which serves as a functional sphincter and prevents the reflux of gastric contents into the esophagus. Cardiac pulp is formed by thickening of the circular muscular layer of the esophagus. In the field of cardia, its thickness is 2-2.5 times greater than in the esophagus. In the region of the cardial notch, the circular layers cross and cross over to the stomach.

The cardiac closure function depends on the physiological usefulness of the muscular fibers of the lower sphincter of the esophagus, the function of the right diaphragmatic leg and the musculature of the stomach, the acute angle between the left wall of the esophagus and the stomach bottom (the angle of the Gys), the diaphragm-esophageal membrane of the Lymer, and the folds of the gastric mucosa (Gubarev's folds ), which under the action of the gastric gas bubble fit tightly to the right edge of the esophageal aperture of the diaphragm.

[1], [2], [3], [4], [5], [6], [7]