What happens when food enters the stomach and explain the role of HCI in digestion process.

Explanation

Digestion in the stomach :
1. Food remains in the stomach for 4 to 5 hours , the rhythmic peristaltic movement churns and mixes the food with gastric juice and make it into a creamy liquid called cyme.
2. The gastric secreation is partly controlled by autonomic reflexes.
3. The secreation of gastric juice begins when the food is in the mouth .
4. the gastric juice contains HCI and proenzymes . The proenzyme pepsinogen , on exposure to HCI gets converted into the active enzymes pepsin which converts proteins into proteoses and peptones (peptides).
5. The HCI provides an acidic medium (p H 1.8) which is optimum for pepsin , kills bacteria and other harmful organisms and avoids putrifaction.

6. The mucus and bicarbonates present in the gastric juice play an important role in lubrication and protection of the mucosal epithelium from the eroding nature of the highly acidic HCI.