Stomach Mucosa

The mucous membrane of the stomach (Tunica mucosa]]) contains tubular glands which form and release the gastric juice. gastric juice is an aqueous liquid containing hydrochloric acid (pH 0,9 to 1,5) and other substances. The gastric mucosa protects itself from damage by the acid gastric juice by forming a thick superficial layer of mucus.

The gastric glands are composed of three different cell types: *main cells: They form the inactive precursor of the enzyme Pepsin, the pepsinogen. This pepsinogen is only converted to pepsin and activated by contact with gastric acid. In this way, destruction of the gastric glands by self-digestion is prevented. *Belegzellen: They produce the hydrogen-ions necessary for the formation of magenic acid. In addition, they form the intrinsic factor. *Nebenzellen: They secrete a mucus that contains hydrogen carbonate ions. Due to their alkaline character, they contribute to the regulation of the pHes in the stomach and thus protect the mucous membrane from damage *G-cells: These cells, which are preferentially located in the antrum of the stomach, have the ability to transmit the hormone Gastrin to produce. This hormone causes an increase in HCl formation in the supporting cells.

After food intake, gastric juice formation can increase by a factor of 100 compared to the fasting state. It is controlled by both nervous and hormonal signals.