Stomach: histology, development and structure

The stomach belongs to the main organs of the digestive tract. It processes all the products that we use. This is due to hydrochloric acid, which is in the stomach. This chemical compound is secreted by special cells. The structure of the stomach is represented by several types of tissues. In addition, cells that secrete hydrochloric acid and other biologically active substances are not located throughout the body. Therefore, anatomically, the stomach consists of several sections. Each of them differs in functional meaning.

Stomach: organ histology

The stomach is a hollow organ of sacciform form. In addition to chemical treatment of chyme, it is necessary for the accumulation of food. To understand how digestion is carried out, one should know what gastric histology is. This science studies the structure of organs at the tissue level. As is known, living matter consists of a multitude of cells. They, in turn, form tissues. The cells of the body are different in structure. Therefore, the tissues are also not the same. Each of them performs a certain function. Internal organs consist of several types of tissues. This ensures their activities.

Not an exception and the stomach. Histology studies 4 layers of this organ. The first of these is the mucosa. It is located on the inner surface of the stomach. Then there is a submucosal layer. It is represented by a fatty tissue in which there are blood and lymphatic vessels, as well as nerves. The next layer is the muscle shell. Thanks to her stomach can contract and relax. The last is the serosa. It comes into contact with the abdominal cavity. Each of these layers consists of cells, which together form a tissue.

Histology of the gastric mucosa

Normal histology of the gastric mucosa is represented by epithelial, glandular and lymphoid tissue. In addition, this shell contains a muscular plate consisting of smooth muscles. A feature of the gastric mucosa is that there are many pits on its surface. They are located between the glands secreting various biological substances. Then there is a layer of epithelial tissue. It is followed by the gland of the stomach. Together with the lymphoid tissue they form their own plate, which is part of the mucosa.

The glandular tissue has a definite structure. It is represented by several entities. Among them:

• Simple glands. They have a tubular structure.
• Branched glands.

The secretory department consists of several exo- and endocrinocytes. The inferior duct of the glandular mucosa leaves the bottom of the pit, located on the surface of the tissue. In addition, cells in this department are also capable of secreting mucus. The gaps between the glands are filled with coarse connective fibrous tissue.

Lymphoid elements may be present in the lamina propria of the mucosa. They are located diffusely, but the entire surface. Then follows the muscular plate. In its composition, there are 2 layers of circular fibers and 1 - longitudinal. He occupies an intermediate position.

Histological structure of the epithelium of the stomach

The upper layer of the mucosa, which contacts the food masses, is the epithelium of the stomach. The histology of this GIT differs from the structure of the tissue in the intestine. Epithelium not only protects the surface of the body from damage, but also has a secretory function. This tissue lining the stomach cavity from the inside. It is located on the entire surface of the mucosa. Not an exception and gastric fossa.

The inner surface of the organ is covered with a single-layer prismatic glandular epithelium. The cells of this tissue are secretory. They are called exocrine cells. Together with the cells of the excretory ducts of the glands, they produce a secret.

Histology of the fundus of the stomach

The histology of the various parts of the stomach is not the same. Anatomically the organ is divided into several parts. Among them:

• Cardiac department. In this place the esophagus passes into the stomach.
• Bottom. In another way this part is called the foundation department.
• The body is represented by large and small curvature of the stomach.
• Antral department. This part is located before the transition of the stomach to the PDK.
• The Pyloric Department (gatekeeper). In this part there is a sphincter that connects the stomach to the PDC. The gatekeeper occupies an intermediate position between these organs.

The fundus of the stomach is of great physiological importance. The histology of this area is complex. In the fundus there are own stomach glands. Their number is about 35 million. The depth of the pits between the fundus glands occupies 25% of the mucosa. The main function of this department is the production of hydrochloric acid. Under the influence of this substance there is an activation of biologically active substances (pepsin), digestion of food, and also protects the body from bacterial and viral particles. Own (base) glands consist of 2 types of cells - exo- and endocrinocytes.

Histology of the submucosal membrane of the stomach

As in all organs, under the mucous membrane of the stomach is a layer of fatty tissue. In its thickness there are vascular (venous and arterial) plexuses. They supply blood to the inner layers of the stomach wall. In particular, the muscular and submucosa. In addition, in this layer there is a network of lymphatic vessels and a nerve plexus. The muscular membrane of the stomach is represented by three layers of musculature. This is a distinctive feature of this body. Outside and inside are longitudinal muscle fibers. They have an oblique orientation. Between them lies a layer of circular muscle fibers. As in the submucosa, there is a nerve plexus and a network of lymphatic vessels. Outside, the stomach is covered with a serous layer. It is a visceral peritoneum.

Benign neoplasms of the stomach and intestines: a histology of a hemangioma

One of the benign neoplasms is hemangioma. Histology of the stomach and intestines for this disease is necessary. After all, despite the fact that education is benign, it should be differentiated from cancer. Histologically, the hemangioma is represented by a vascular tissue. The cells of this tumor are completely differentiated. They do not differ from the elements that make up the arteries and veins of the body. Most often, the hemangioma of the stomach is formed in the submucosa. Typical localization for this benign neoplasm is the pyloric department. The tumor can have different sizes.

In addition to the stomach, hemangiomas can be localized in the small and large intestines. These formations rarely make themselves felt. Nevertheless, the diagnosis of hemangiomas is important. With large sizes and constant traumatization (chyme, calves), serious complications can occur. The main one is profuse gastrointestinal bleeding. Benign neoplasm is difficult to suspect, as in most cases there are no clinical manifestations. When an endoscopic examination, a dark red or cyanotic round spot is found that rises above the mucous membrane. In this case, the diagnosis is "hemangioma." The histology of the stomach and intestines is crucial here. In rare cases, hemangioma undergoes malignant degeneration.

Regeneration of the stomach: histology in the healing of ulcers

One of the indications for histological examination is gastric ulcer. With this pathology, an endoscopic examination (FEGDS) is performed with taking a biopsy. Histology is mandatory for suspected malignancy of the ulcer. Depending on the stage of the disease, the tissue obtained can be different. When the ulcer is healed, the cicatrix is examined. Histology in this case is necessary only in the presence of symptoms, due to which it is possible to suspect malignant degeneration of the tissue. If there is no malignancy, then in the analysis cells of coarse connective tissue are found. With malignant stomach ulcers, the histological pattern may be different. It is characterized by a change in the cellular composition of the tissue, the presence of undifferentiated elements.

What is the purpose of the histology of the stomach?

One of the organs of the digestive tract, in which neoplasms often develop, is the stomach. Histology should be performed in the presence of any change in the mucosa. Indications for this study are the following diseases:

• Atrophic gastritis. This pathology is characterized by impoverishment of the cellular composition of the mucous membrane, inflammatory phenomena, a decrease in the secretion of hydrochloric acid.
• Rare forms of gastritis. These include lymphocytic, eosinophilic and granulomatous inflammation.
• Chronic peptic ulcer of stomach and duodenum.
• The development of "small signs" according to Savitsky. These include general weakness, decreased appetite and performance, weight loss, a feeling of discomfort in the abdomen.
• Detection of polyps of the stomach and other benign neoplasms.
• A sudden change in the clinical picture with a long-lasting peptic ulcer. These include a decrease in the intensity of the pain syndrome, the development of aversion to meat food.

The listed pathologies refer to precancerous diseases. This does not mean that the patient has a malignant tumor, and its localization is the stomach. Histology helps determine which changes are observed in the tissues of the organ. To prevent the development of malignant degeneration, it is worthwhile to conduct research as early as possible and take action.

Results of histology of the stomach

The results of the histological examination may be different. If the tissue of the organ is not changed, then a normal prismatic single-layered glandular epithelium is found in microscopy. If you take a deeper layer on the biopsy, you can see smooth muscle fibers, adipocytes. If the patient has a scar from a prolonged ulcer, then a coarse fibrous connective tissue is found. In benign formations the results of histology may be different. They depend on the tissue from which the tumor developed (vascular, muscle, lymphoid). The main feature of benign formations is the maturity of the cells.

Gastric tissue sampling for histology: the technique of conducting

To perform a histological examination of the stomach tissue, it is necessary to perform a biopsy of the organ. In most cases, it is carried out with the help of endoscopy. The apparatus for performing PHAGS is placed in the lumen of the stomach and several pieces of organ tissue are cleaved off. It is desirable to take biopsy from several remote sites. In some cases, tissue for histological examination is taken during the operation. After that, the laboratory conducts thin sections from the biopsy specimen, which is examined under a microscope.

How long does the histological analysis of the stomach tissue take?

If you suspect a cancer, you need a histology of the stomach. How long does this analysis take? Only the attending physician can answer this question. The average histology takes about 2 weeks. This concerns planned studies, for example, when removing a polyp.

During the operation, an urgent histological examination of the tissue may be necessary. In this case, the analysis takes no more than half an hour.

In which clinics is the histological analysis performed?

Some patients are interested in: where is it possible to make a histology of the stomach? This study is conducted in all clinics that have the necessary equipment and laboratory. Urgent histology is conducted in oncological dispensaries, some surgical hospitals.