Pancreatic exocrine secretion is stimulated by the following except:

Correct Answer: B

Rationale: The correct answer is B: Entropeptidase. Pancreatic exocrine secretion is primarily stimulated by hormones like CCK and the presence of food in the stomach. Vagal stimulation can also trigger pancreatic secretion. However, enteropeptidase is an enzyme that activates trypsinogen to trypsin in the small intestine, not a direct stimulator of pancreatic exocrine secretion. Therefore, choice B is the exception among the given options.

Correct Answer: B

Rationale: The correct answer is B: juvenile polyp. Juvenile polyps are benign growths commonly found in the colon and rectum of children. They have no significant tendency to undergo malignant transformation due to their non-neoplastic nature. They are typically small, solitary, and have a smooth surface. Familial polyposis (choice A) is a hereditary condition characterized by numerous polyps in the colon, which can progress to colorectal cancer. Villous adenomas (choice C) are precancerous lesions with a higher risk of malignant transformation. Carcinoid tumors (choice D) are neuroendocrine tumors that can be found in various parts of the body, including the gastrointestinal tract, and have the potential to be malignant.

Correct Answer: B

Rationale: The correct answer is B because HCl secretion is primarily carried out by parietal cells in the stomach lining. Parietal cells contain proton pumps that actively secrete HCl to aid in digestion. Chief cells secrete pepsinogen, not HCl (A is incorrect). Gastrin actually stimulates HCl secretion, so it doesn't inhibit it (C is incorrect). Acetylcholine (Ach) is a neurotransmitter that can stimulate, not inhibit, HCl secretion (D is incorrect). Therefore, option B is the correct choice based on the roles of parietal cells in HCl secretion.

Correct Answer: D

Rationale: The correct answer is D because none of the statements are true. A is incorrect because fat-soluble vitamins are incorporated into chylomicrons before absorption. B is incorrect because triglycerides are resynthesized in the intestinal cell but packaged into chylomicrons, not directly exported. C is incorrect because pancreatic lipase functions best at a pH of around 7-8, not 3. So, the correct answer is D as all the other choices are incorrect.

Correct Answer: C

Rationale: The correct answer is C: Bile. Bile is not a component of gastric juice; it is produced by the liver and stored in the gallbladder to aid in digestion in the small intestine. Pepsinogen, hydrochloric acid, and mucus are all components of gastric juice. Pepsinogen is the inactive form of pepsin, an enzyme that breaks down proteins. Hydrochloric acid helps in the digestion of food and kills bacteria. Mucus protects the stomach lining from the acidic environment.