Question

Secretion of gastric juice is controlled by
(a) Enterogastrone
(b) Cholecystokinin
(c) Gastrin
(d) Motilin

Answer 1

Hint: The secretion of gastric juice is controlled by a hormone that is released by glandular cells located in a muscular bag like an organ. The entry of food into the alimentary canal stimulates its release.

Complete answer:
Gastrin is secreted by the G-cells of the pyloric portion of the stomach and the duodenum. Its function is to promote the secretion of gastric juice and increases movements of the stomach. It also induces the contraction of the lower esophageal sphincter while relaxing the pyloric sphincter. Gastric juice consists of all the secretions from gastric glands.

Additional Information: -The gastric glands consist of chief cells, parietal cells, mucous cells. Chief cells secrete pepsinogen in its inactive form that upon conversion to pepsin initiates the digestion of proteins. Parietal cells secrete HCl and an intrinsic factor that helps in the absorption of Vitamin B12. Mucous cells release alkaline mucus to protect the stomach wall from the corrosive action of HCl.
-Enterogastrone is secreted by the epithelium of the duodenum. Its function is to inhibit gastric secretion as well as the motility of the incoming chyme from the stomach. As its secretion is the reason for the slowing down of gastric secretion, it is also known as the gastric inhibitory peptide.
-Cholecystokinin is secreted by the glandular cells of the duodenum. It stimulates the secretion of pancreatic juice and regulates the release of bile from the gallbladder.
-Motilin is a peptide hormone discharged by the enteroendocrine cells located in the mucosa of the anterior small intestine. It controls the contraction of smooth muscles located in the upper gastrointestinal tract.
So, the correct answer is ‘Gastrin.’

Note: -The stomach is located between the oesophagus and the small intestine. The digestive actions in the acidic environment of the stomach reduce the incoming food particles from the oesophagus to a solution known as chyme.
-Its constituents include molecular fragments of proteins and polysaccharides, droplets of fat, and salt, water, and various other small molecules ingested in the food.