Stimulating the Production of Pancreatic Juice and Bicarbonate

The correct answer to the given question is option C, which states that cholecystokinin and secretin are the hormones that stimulate the production of pancreatic juice and bicarbonate.

Explanation:
Pancreatic juice is an important digestive fluid secreted by the pancreas, which plays a vital role in the digestion and absorption of nutrients in the small intestine. It contains enzymes that break down carbohydrates, proteins, and fats, as well as bicarbonate ions that neutralize the acidic chyme (partially digested food) coming from the stomach.

Cholecystokinin (CCK):
Cholecystokinin is a hormone produced by the cells of the duodenum in response to the presence of partially digested proteins and fats in the small intestine. Its main function is to stimulate the release of pancreatic enzymes and bile from the gallbladder. When CCK is released into the bloodstream, it binds to specific receptors on the pancreatic acinar cells, which triggers the secretion of pancreatic enzymes into the pancreatic ducts. These enzymes then flow into the small intestine through the pancreatic duct, where they help in the digestion of proteins and fats.

Secretin:
Secretin is another hormone produced by the cells of the duodenum in response to the acidic chyme entering the small intestine from the stomach. Its primary role is to stimulate the secretion of bicarbonate ions from the pancreas and bile ducts. When secretin is released, it binds to receptors on the pancreatic duct cells, causing an increase in the production and release of bicarbonate ions. The bicarbonate ions then mix with the pancreatic enzymes in the pancreatic ducts, forming pancreatic juice that is rich in bicarbonate. This bicarbonate-rich pancreatic juice helps to neutralize the acidic chyme, creating an optimal pH environment for the pancreatic enzymes to function effectively.

In summary, cholecystokinin and secretin are the hormones responsible for stimulating the production of pancreatic juice and bicarbonate. Cholecystokinin triggers the release of pancreatic enzymes, while secretin stimulates the secretion of bicarbonate ions. Both of these hormones work together to ensure efficient digestion and absorption of nutrients in the small intestine.