The stomach (lat. Gaster, ventriculus) is an extension of the gastrointestinal tract, forming something like a reservoir in which the collected food is digested. It is located on the left side of the body in the hypochondrium. The axis drawn through the stomach is directed from above and to the left, to the bottom and to the right. By its appearance, the structure of the stomach is presented in the form of a hook or horn, although mainly its shape can vary. The length of the organ is usually 25-30 cm, and the width varies from 12 to 14 centimeters. Capacity depends on how much food there is. However, its average volume is 1-3 liters.
The stomach is adjacent to many important abdominal organs. In front is the liver, behind the spleen, left kidney and adrenal glands, pancreas and duodenum. Therefore, the painful processes in these organs can also affect the stomach, although the opposite situation is more common when, for example, a stomach ulcer penetrates the pancreas.
The human stomach is an elongated and strong muscle organ, which has a fairly complex structure. The cardiac part, the bottom, the body and the pyloric part - this is the structure of the stomach. The cardiac hole is located near the heart, is the entrance of the esophagus into the stomach. The bottom is above the connection with the esophagus. The body of the stomach is the largest part of the organ, which borders the bottom of the pylorus, and the top of the bottom of the stomach. The pylorus or pyloric part is a long canal, at the end of which is the entrance to the duodenum.
The anatomical structure of the stomach is composed of three layers. From the outside, to moisturize, the body is surrounded by a serous membrane. The middle layer of the muscle membrane consists of the outer longitudinal layer, the middle circular and inner oblique layer. The deepest layer is the mucous membrane, which also forms the submucosal part. All layers of the stomach perform a specific purpose. So, the serous membrane constantly produces fluid to reduce friction between organs, the muscle layer provides the motor function of the stomach, and the mucus enveloping the walls of the stomach, protects it from destruction.
The stomach has a rather unusual curved shape in structure, but this is nothing special. The macroscopic structure of the stomach is a baggy concavity, which is its top point and is called the bottom of this organ. All food gets into this part of the stomach. Only after saving portions of food here, everything else gradually moves to the lower part of the stomach for intensive digestion and sterilization with gastric juice.
Four main functions of the stomach can be distinguished - chopping food, sterilizing it, digesting protein, and digesting sugar. Grinding products is carried out both through chemical processes and through muscle movements (mechanical processes). After eating, contractions in the stomach allow you to mix, grind and, finally, move small portions of the contents into the small intestine. More importantly, however, is what is produced in the stomach and that is what determines its uniqueness. The contents of the stomach is a food mixed with digestive enzymes and gastric juice. The main components of the juice are hydrochloric acid and pepsin, and their stomach glands produce it. Hydrochloric acid is aggressive for all parasites and bacteria, and is active only in very strong acidic environments. It prevents the absorption of sugar, which is produced from the first contact of food with saliva, because the acidic environment excludes the enzymes that are responsible for this. Such a killer mixture (fortunately, only for bacteria) effectively prepares food for further processing in the duodenum.