We eat and drink our entire lives, because we need energy to function normally and move. But if we have consumed the food once, ask no more wondering what is happening with it. This article describes the operation of food in the stomach.
In the stomach the swallowed food is stored for a while. There occurred almost continuously strong peristalsis, causing the food is kneaded and mixed with gastric juice. Peptic glands produce a day, which are located in the stomach wall, approximately 2.5 liters of gastric juice. Gastric juice contains mucus, hydrochloric acid and the enzyme pepsin. By kneading and mixing the food is by the hydrochloric acid very slowly.
Pepsin only works well in highly acidic conditions. It is the only enzyme in our body whose optipum pH is so low. Pepsin is a proteinase, and thus breaks down proteins. The stops starch digestion in the stomach, as soon as it comes into contact with food chunk maasap. Amylase has an optimum pH of about 7. The starch digestion can still go on because the food is deposited in layers on the stomach, later bites come so only after some time in contact with the gastric juice. Then, the amylase is also digested. Fat digestion does not take place in the stomach.
An important function of the hydrochloric acid in the stomach is to protect: the majority of bacteria and germs pass through death, moreover, sharp particles dissolve in hydrochloric acid. The mucus in gastric juice forms a protective layer against the stomach, the hydrochloric acid would otherwise damage the stomach lining.
In the stomach, will find itself so the first step of the protein digestion site. Pepsin breaks, just as other proteinases, not random proteins, it can only loosen the bond between certain combinations of amino acids. The proteins are thus divided so in larger or smaller peptides. The following steps are described later in the intestinal tract broken by other proteinases other combinations, so that finally releasing the individual amino acids. Proteins that do not prevent such combinations are therefore not consumed.
Pepsin breaks down the protein in the glandular cells not finished, in that it is not produced as an active enzyme. The wall cells in the glands make pepsinogen, a non-active protein, other cells produce HCl. In the stomach cavity, the HCl activates the pepsinogen, there by to 'cut' off a piece through which the active pepsin comes out that activates, in turn, more pepsinogen. So can start a chain reaction. This is a positive feedback process.
The inside of the stomach is coated with a thick layer of mucus, which makes sure that pepsin does not damage the stomach wall. Always this happens quite a bit. If you see food, smells or tastes the activity is started with impulses via the autonomic nervous system. Certain components excite in the food in the stomach than the stomach wall tissue to produce the hormone gastrin. This is in the bloodstream and stimulates the stomach wall in order to produce gastric juice. If the pH is too low, the production of gastrin and also stops the produc of gastric juice. Via the stomach wall are hardly absorbed nutrients in the blood.