The stomach is a major food storage station; the pyloric sphincter controls the release of partially digested food — chyme — into the small intestine.
- mechanical digestion: Peristaltic movement of the stomach churns and breaks up food.
- chemical digestion : HCl and pepsin secreted by gastric glands.
- HCl released by parietal cells maintain pH at about 2; HCl participates in acid hydrolysis.
- Pepsin, a peptidase, is secreted by chief cells in the form of an inactive zymogen — pepsinogen - which is converted to the active pepsin by the low pH environment and by autocatalysis.
- mucus secreted by the mucosal cells and the production of an inactive zymogen both protect the stomach from digesting itself.
- the low pH environment of the stomach helps to defend against invasion of pathogens.
- mechanical digestion: Peristaltic movement of the stomach churns and breaks up food.
- chemical digestion : HCl and pepsin secreted by gastric glands.
- HCl released by parietal cells maintain pH at about 2; HCl participates in acid hydrolysis.
- Pepsin, a peptidase, is secreted by chief cells in the form of an inactive zymogen — pepsinogen - which is converted to the active pepsin by the low pH environment and by autocatalysis.
- mucus secreted by the mucosal cells and the production of an inactive zymogen both protect the stomach from digesting itself.
- the low pH environment of the stomach helps to defend against invasion of pathogens.
