Role and function of the stomach - the stomach homogenises ingested food by peristaltic movement, hydrochloric acid is produced to reduce the number of bacteria, and pepsin starts digesting proteins in an acidic medium.
Some nutrients are already in the Stomachare absorbed in.
We distinguish between the following three phases of digestion:
- cephalic (brain) phase: the sight and taste of food causes excitation of the vagus nerve, which stimulates salivation in the oral cavity and acid secretion in the stomach;
- gastricus (Stomach) phase: gastric distension and excitation of the vagus nerve induces gastrin release, which results in additional gastric acid secretion, favouring the conversion of pepsinogen to pepsin, and thus protein digestion;
- intestinal (gut) phase: mainly due to the action of hydrochloric acid on the horseshoe and small intestine hormones produced in the mucous membranes of the gastrointestinal tract (mainly the jejunum) reduce the release of gastrin, thereby reducing acid secretion.