An intestinal hormone that stimulates mucus secretion by the submucosal duodenal glands:
A) ?secretin.
B) ?cholecystokinin.
C) ?enterocrinin.
D) ?GIP.
E) ?gastrin.
The correct answer and explanation is :
Correct Answer: C) Enterocrinin
Explanation:
Enterocrinin is an intestinal hormone that plays a crucial role in stimulating mucus secretion from the submucosal duodenal glands, also known as Brunner’s glands. These glands are located in the submucosa of the duodenum and are responsible for secreting an alkaline mucus that helps neutralize the acidic chyme entering the small intestine from the stomach.
When acidic chyme or partially digested food reaches the duodenum, enterocrinin is released by the enteroendocrine cells of the small intestine. This hormone acts on the Brunner’s glands, promoting the secretion of mucus that protects the duodenal lining from the harsh effects of stomach acid and digestive enzymes.
Why Not the Other Options?
- Secretin (A): Secretin is a hormone released by the S cells of the duodenum in response to acidic chyme. Its primary function is to stimulate the pancreas to release bicarbonate-rich fluid, which helps neutralize stomach acid. It does not directly stimulate mucus secretion by the duodenal glands.
- Cholecystokinin (B): Cholecystokinin (CCK) is secreted by the small intestine and mainly stimulates the gallbladder to release bile and the pancreas to release digestive enzymes. It is not responsible for mucus secretion.
- Gastric Inhibitory Peptide (GIP) (D): GIP primarily functions to reduce gastric motility and stimulate insulin release in response to glucose. It does not play a role in mucus secretion.
- Gastrin (E): Gastrin is secreted by the G cells of the stomach and primarily stimulates the secretion of gastric acid from the parietal cells. It has no direct role in mucus secretion by the duodenal glands.
Thus, Enterocrinin (C) is the correct answer as it specifically triggers mucus secretion by the submucosal duodenal glands.
