The stomach is one of the main organs of the digestive tract. It processes all the products that we use. This is due to hydrochloric acid, which is present 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 organ. Therefore, anatomically, the stomach consists of several sections. Each one is different in function.
Stomach: histology of the organ
The stomach is a hollow, bag-shaped organ. In addition to the chemical processing of chyme, it is necessary for the accumulation of food. To understand how digestion is carried out, you should know what the histology of the stomach is. This science studies the structure of organs at the level of tissues. As you know, living matter consists of many cells. They, in turn, form tissues. The cells of the body are different in their structure. Therefore, the fabrics are also not the same. Each of them performs a specificfunction. The internal organs are made up of several types of tissues. This ensures their activities.
The stomach is no exception. Histology studies 4 layers of this organ. The first of these is the mucous membrane. It is located on the inner surface of the stomach. Next is the submucosal layer. It is represented by adipose tissue, which contains blood and lymphatic vessels, as well as nerves. The next layer is the muscle membrane. Thanks to it, the stomach can contract and relax. The last is the serous membrane. It is in contact with the abdominal cavity. Each of these layers is made up of cells that together form 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 mucous layer of the stomach is that there are many pits on its surface. They are located between the glands that secrete various biological substances. Then there is a layer of epithelial tissue. It is followed by the gland of the stomach. Together with lymphoid tissue, they form their own plate, which is part of the mucous membrane.
Glandular tissue has a certain structure. It is represented by several formations. Among them:
- Simple glands. They have a tubular structure.
- Branched glands.
The secretory section consists of several exo- and endocrinocytes. The excretory duct of the glands of the mucous membrane goes to the bottom of the fossa located on the surface of the tissue. In addition, the cells in this section are also able to secrete mucus. The spaces between the glands are filled with coarse connective fibrous tissue.
Lymphoid elements may be present in the lamina propria. They are located diffusely, but the entire surface. Next comes the muscle plate. It contains 2 layers of circular fibers and 1 - longitudinal. He occupies an intermediate position.
Histological structure of the stomach epithelium
The upper layer of the mucous membrane, which is in contact with food masses, is the epithelium of the stomach. The histology of this section of the gastrointestinal tract differs from the structure of the tissue in the intestine. The epithelium not only protects the surface of the organ from damage, but also has a secretory function. This tissue lines the inside of the stomach. It is located on the entire surface of the mucous membrane. The gastric pits are no exception.
The inner surface of the organ is covered with a single layer of prismatic glandular epithelium. The cells of this tissue are secretory. They are called exocrinocytes. Together with the cells of the excretory ducts of the glands, they produce a secret.
Histology of the fundus of the stomach
Histology of different parts of the stomach is not the same. Anatomically, the body is divided into several parts. Among them:
- Cardiac department. At this point, the esophagus passes intostomach.
- Dno. In another way, this part is called the fundus.
- The body is represented by the greater and lesser curvature of the stomach.
- Antral department. This part is located before the transition of the stomach into the duodenum.
- Pyloric department (pylorus). In this part there is a sphincter that connects the stomach to the duodenum. 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. The fundus has its own glands of the stomach. Their number is about 35 million. The depth of the pits between the fundic glands occupies 25% of the mucous membrane. The main function of this department is the production of hydrochloric acid. Under the influence of this substance, biologically active substances (pepsin) are activated, food is digested, and the body is protected from bacterial and viral particles. Own (fundal) glands consist of 2 types of cells - exo- and endocrinocytes.
Histology of the submucosa of the stomach
As in all organs, under the mucous membrane of the stomach is a layer of adipose tissue. Vascular (venous and arterial) plexuses are located in its thickness. They supply blood to the inner layers of the stomach wall. In particular, the muscular and submucosal membranes. In addition, this layer has a network of lymphatic vessels and a nerve plexus. The muscular layer of the stomach is represented by three layers of muscles. This is a distinctive feature of this body. Outside and inside are longitudinal muscle fibers. They have an oblique direction. 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 represents the visceral peritoneum.
Benign neoplasms of the stomach and intestines: histology of hemangioma
One of the benign neoplasms is hemangioma. Histology of the stomach and intestines in this disease is necessary. Indeed, despite the fact that education is benign, it should be differentiated from cancer. Histologically, hemangioma is represented by vascular tissue. The cells of this tumor are completely differentiated. They are no different from the elements that make up the arteries and veins of the body. Most often, hemangioma of the stomach is formed in the submucosal layer. A typical localization for this benign neoplasm is the pyloric region. The tumor can vary in size.
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 trauma (by chyme, feces), serious complications can occur. The main one is profuse gastrointestinal bleeding. A benign neoplasm is difficult to suspect, since in most cases there are no clinical manifestations. Endoscopy revealsa dark red or cyanotic rounded spot that rises above the mucous membrane. In this case, a diagnosis of hemangioma is made. The histology of the stomach and intestines is of decisive importance. In rare cases, hemangioma undergoes malignant transformation.
Gastric regeneration: histology in ulcer healing
One of the indications for histological examination is gastric ulcer. With this pathology, an endoscopic examination (FEGDS) is performed with a biopsy. Histology is required if malignancy of the ulcer is suspected. Depending on the stage of the disease, the resulting tissue may be different. When the ulcer heals, the scar of the stomach is examined. Histology in this case is needed only if there are symptoms due to which malignant degeneration of the tissue can be suspected. If there is no malignancy, then cells of coarse connective tissue are found in the analysis. With malignant stomach ulcers, the histological picture 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 gastric histology?
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 mucosal change. The following diseases are considered indications for this study:
- Atrophic gastritis. This pathology is characterized by depletion of the cellular composition of the mucous membrane, inflammation, and a decrease in the secretion of hydrochloric acid.
- Rare forms of gastritis. These include lymphocytic, eosinophilic, and granulomatous inflammation.
- Chronic peptic ulcer of the stomach and duodenum.
- 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 gastric polyps and other benign neoplasms.
- Sudden change in the clinical picture in a long-term peptic ulcer. These include a decrease in the intensity of the pain syndrome, the development of aversion to meat food.
The listed pathologies are precancerous diseases. This does not mean that the patient has a malignant tumor, and its localization is the stomach. Histology helps to determine exactly what changes are observed in the tissues of the organ. To prevent the development of malignant degeneration, it is worth conducting an investigation as early as possible and taking action.
Gastric histology results
Histological findings may vary. If the tissue of the organ is not changed, then microscopy reveals a normal prismatic single-layer glandular epithelium. When taking a biopsy of deeper layers, you can see smooth muscle fibers, adipocytes. If the patient has a scar from a protracted ulcer, then coarse fibrous connective tissue is found. With benign formations, the results of histology may be different. They depend on the tissue from which the tumor developed.(vascular, muscular, lymphoid). The main feature of benign formations is the maturity of the cells.
Taking stomach tissue for histology: methodology
To perform a histological examination of the stomach tissue, it is necessary to perform a biopsy of the organ. In most cases, it is done through endoscopy. An apparatus for performing FEGDS is placed in the lumen of the stomach and several pieces of organ tissue are cleaved off. Biopsy specimens should preferably be taken from several distant sites. In some cases, tissue for histological examination is taken during surgery. After that, thin sections from the biopsy are taken in the laboratory and examined under a microscope.
How long does a histological analysis of stomach tissue take
If cancer is suspected, gastric histology is necessary. How long does this analysis take? Only the attending physician can answer this question. On average, histology takes about 2 weeks. This applies to 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.
Which clinics perform histological analysis?
Some patients are interested: where can I urgently do a histology of the stomach? This study is carried out in all clinics with the necessary equipment and laboratory. Urgent histology is carried out in oncologicaldispensaries, some surgical hospitals.
