The hormone secretin stimulates the stomach to secrete acid and enzymes.
True
False
The correct answer and explanation is:
Correct Answer: False
Explanation:
Secretin is not responsible for stimulating the stomach to secrete acid and enzymes. Instead, it plays a different role in the digestive process. Secretin is a hormone produced by the S cells of the duodenum, which is the first section of the small intestine. It is released in response to acidic chyme (partially digested food mixed with stomach acid) entering the duodenum from the stomach.
Once released, secretin has several key functions, but stimulating stomach acid secretion is not one of them. Its primary role is to help neutralize the acidity of the chyme to create a more favorable environment for the enzymes in the small intestine to function. It does this by:
- Stimulating the pancreas to release bicarbonate-rich fluid into the duodenum. Bicarbonate helps to neutralize the acidic chyme.
- Inhibiting gastric emptying and gastric acid secretion from the stomach to prevent the duodenum from becoming too acidic.
- Enhancing the effect of other hormones, such as cholecystokinin (CCK), which aid in digestion by stimulating the secretion of pancreatic enzymes and bile.
In contrast, the hormones gastrin and histamine are primarily responsible for stimulating acid secretion in the stomach. Gastrin, produced by G cells in the stomach lining, directly stimulates the stomach’s parietal cells to produce hydrochloric acid. Histamine acts on the H2 receptors of parietal cells to enhance acid secretion.
Therefore, the statement is false: Secretin does not stimulate the stomach to secrete acid and enzymes. It actually works to reduce acid levels and protect the small intestine, highlighting its regulatory and protective role in digestion.