Answer :
Cholecystokinin (CCK) stimulates the gallbladder to contract and secrete bile, increases the secretion of pancreatic enzymes, and decreases gastric acid secretion in response to protein- and fat-rich chyme. The correct options are 1,3,5,4.
The release of cholecystokinin (CCK) by duodenal enteroendocrine cells in response to protein- and fat-rich chyme leads to several physiological responses:
- Increased secretion of bile from the gallbladder.
- Increased contraction of the gallbladder, causing bile to be secreted into the duodenum.
- Increased secretion of pancreatic enzymes from the pancreas into the pancreatic fluid.
- Decreased secretion of gastric acid, as CCK acts on the vagal neurons, providing a satiety signal.
The presence of proteins and fats in the duodenum stimulates the secretion of CCK, which then not only enhances the activity of secretin but also directs the activities of the pancreas and gallbladder to facilitate digestion. Hence the correct options are 1,3,5,4.