The structure of the stomach: departments, layers
The stomach is an unpaired hollow sac-like organ of the gastrointestinal tract. The length of the stomach is about 26 centimeters. Its volume is from one to several liters, it depends on the age and preferences of the person in food. If you project its location on the abdominal wall, it is located in the epigastric region. The structure of the stomach can be divided into sections and layers.
The structure of the stomach allocates four sections.
This is the first section. The place where the esophagus communicates with the stomach. The sphincter is formed by the muscular layer of this section, which prevents the return of food.
Stomach (bottom) of the stomach
It has a dome shape, it accumulates air. In this section are glands secreting gastric juice with hydrochloric acid.
The largest section of the stomach. It is located between the gatekeeper and the bottom.
Pyloric department (gatekeeper)
The last section of the stomach. It allocates a cave and a channel. In the cave there is an accumulation of food, which is partially digested. The sphincter is located in the canal, through which food enters the next section of the digestive tract (duodenum).The sphincter also prevents the return of food from the intestine into the stomach and vice versa.
Structure of the stomach
It is exactly the same as that of all the hollow organs of the gastrointestinal tract. There are four layers in the wall. The structure of the stomach is designed to perform its basic functions. It is about digestion, mixing of food, partial absorption).
Layers of the stomach
It completely lines the inner surface of the stomach. The entire mucous layer is covered with cylindrical cells that produce mucus. It protects the stomach from exposure to hydrochloric acid due to its bicarbonate content. On the surface of the mucous layer there are pores (the mouth of the glands). Also in the mucous layer emit a thin layer of muscle fibers. Thanks to these fibers folds are formed.
It consists of loose connective tissue, blood vessels and nerve endings. Thanks to him, there is a constant nourishment of the mucous layer and its innervation. Nerve endings regulate the digestive process.
Muscular layer (skeleton of the stomach)
It is represented by three rows of multidirectional muscle fibers, due to which the promotion and mixing of food occurs. The nerve plexus (auerbakhovo), which is located here, is responsible for the tone of the stomach.
This is the outer layer of the stomach, which is a derivative of the peritoneum. It has the appearance of a film that produces a special liquid. Thanks to this fluid, friction between organs is reduced. In this layer are nerve fibers that are responsible for the pain symptom that occurs when various diseases of the stomach.
Glands of the stomach
As already mentioned, are located in the mucous layer. They are bag-shaped, because of which they go deep into the submucosal layer. From the mouth of the gland is the migration of epithelial cells, which contribute to the constant restoration of the mucous layer. The walls of the gland are represented by three types of cells, which in turn produce hydrochloric acid, pepsin and biologically active substances.