Question

describe the process of gastric digestion. What cells are involved and what do they secrete? How do they produce those secretions? How is gastric secretion and motility regulated by the GI tract, nervous system and endocrine system?

Answer 1

• The digestive system includes the gastrointestinal tract and the accessory digestive organs. function of digestive system is Ingestion , secretion, mixing and propulsion .digestion , absorption and defecation.
• Gastric digestion is part of digestion carried on in the stomach by enzymes of gastric juices.
• The process of gastric digestion is a period in which swallowed and semi digested proteins activate gastric activity, about 2/3 of gastric juices secreted during this phase. ingested food stimulates gastric activity in two ways
• by stretching the stomach and .
• by raising the PH of its contents.
• Mucous and chief cells both involved in gastric digestion and secretes Pepsinogen , an inactive zymogen which secreted into gastric juice from both mucous and chief cells
• The hormones which are involved in controlling gestrointestinal motility ,are cholecystokinin ,gastrin and secretin inhibit contractions thereby decreasing intragastric pressure and slowing gastric emptying of liquids