D. Increases gastric motility – Explanation
Gastrointestinal hormones
Below is a brief summary of the major hormones involved in food digestion:
| Source | Stimulus | Actions | |
| Gastrin | G cells in antrum of the stomach |
Distension of stomach, vagus nerves (mediated by gastrin-releasing peptide), luminal peptides/amino acids Inhibited by: low | Increase HCL, pepsinogen and IF secretion, increases gastric motility, trophic effect on gastric mucosa |
| CCK | I cells in upper small intestine | Partially digested proteins and triglycerides |
Increases secretion of enzyme-rich fluid from pancreas, contraction of gallbladder and relaxation of sphincter of Oddi, decreases gastric emptying,trophic effect on pancreatic acinar cells, inducessatiety |
| Secretin | S cells in upper small intestine | Acidic chyme, fatty acids | Increases secretion of bicarbonate-rich fluid from pancreas and hepatic duct cells, decreases gastric acid secretion, trophic effect on pancreatic acinar cells |
| VIP | Smal lintestine, pancreas |
Neural | Stimulates secretion by pancreas and intestines, inhibits acid secretion |
| Somatostatin | D cells in the pancreas & stomach |
Fat, bile salts and glucose in the intestinal lumen |
Decreases acid and pepsin secretion, decreasesgastrin secretion, decreases pancreatic enzyme secretion, decreases insulin and glucagon secretion inhibits trophic effects of gastrin, |
