Which hormone prevents excessive gastric activity?

Correct Answer: B

Rationale: The correct answer is Enterogastrone. Enterogastrone is a hormone that inhibits excessive gastric activity by slowing down stomach contractions and emptying. Gastrin (choice A) stimulates gastric acid secretion, secretin (choice C) regulates pH levels in the duodenum, and cholecystokinin (choice D) stimulates the release of digestive enzymes and bile.

Correct Answer: A

Rationale: Mucus is produced by the salivary glands to moisten food and aid in swallowing. Additionally, the intestinal glands secrete mucus to protect the lining of the intestines. The other choices, esophageal glands, pineal gland, and islets of Langerhans, are not involved in the production of mucus in the digestive system.

Correct Answer: C

Rationale: The correct answer is C: pancreas. Secretin stimulates the pancreas to release bicarbonate, which acts as a buffering solution to neutralize the acid entering the duodenum from the stomach. This process helps in maintaining the pH balance in the small intestine. Choice A, stomach, is incorrect as the stomach does not produce the buffering solution needed for the duodenum. Choice B, liver, is incorrect because secretin does not directly stimulate the liver to produce a buffering solution. Choice D, oxyntic cells, is also incorrect as these cells in the stomach are responsible for producing gastric acid, not the buffering solution needed in the duodenum.

Correct Answer: A

Rationale: The correct answer is A: bile. Bile acts as an emulsifier, breaking down fats into smaller droplets to aid in digestion and absorption. Trypsin is a digestive enzyme that acts on proteins, not fats. Lipase is an enzyme that breaks down fats, but it doesn't act as an emulsifier. Cholecystokinin (CCK) is a hormone that stimulates the release of digestive enzymes, including lipase, but it is not directly involved in emulsification.

Correct Answer: B

Rationale: Cholecystokinin (CCK) is the hormone responsible for stimulating the gallbladder to contract and release bile into the small intestine. Secretin primarily acts on the pancreas to stimulate the secretion of bicarbonate-rich fluid. Gastrin functions in the stimulation of gastric acid secretion, while Gastric inhibitory polypeptide (GIP) plays a role in inhibiting gastric acid secretion and stimulating insulin release.