The pancreatic islets produce

Correct Answer: B

Rationale: The correct answer is B because the pancreatic islets, also known as the islets of Langerhans, are responsible for producing hormones such as insulin, glucagon, and somatostatin. Insulin helps lower blood sugar levels, glucagon raises blood sugar levels, and somatostatin regulates the release of both insulin and glucagon. The other choices are incorrect because mucus is produced by goblet cells in the intestines, enterokinase is produced by the duodenum to activate pancreatic enzymes, and digestive enzymes are produced by the exocrine cells in the pancreas, not the pancreatic islets.

Correct Answer: C

Rationale: Rationale for Correct Answer C: Enteropeptidase converts trypsinogen to trypsin by cleaving a peptide sequence that blocks the active site of trypsin. This is crucial for the activation of trypsin, a key enzyme in protein digestion. Trypsin then activates other pancreatic enzymes. This process ensures efficient breakdown of proteins in the small intestine. Summary of Incorrect Choices: A: Pepsinogen is not secreted by the pancreas and does not require removal of a peptide sequence from the active site for activation. B: Pancreatic α-amylase is responsible for breaking down starch into maltose and not glucose. D: Pancreatic secretion of hydrochloric acid is not directly related to the activation of pancreatic enzymes; it is the role of stomach acid to provide an acidic environment for pepsin activation.

Correct Answer: C

Rationale: The correct answer is C because the formation of tripartite synapses with astrocytes and neurons does not provide direct protection to the brain. Tripartite synapses involve communication between neurons and astrocytes, primarily for synaptic regulation and plasticity. The blood-brain barrier (A) physically protects the brain by restricting the passage of harmful substances. Microglia (B) function as the brain's immune cells, defending against pathogens and removing cellular debris. Therefore, choices A and B contribute to the brain's protection, making them incorrect answers.

Correct Answer: A

Rationale: Rationale: A is false because exercise has been shown to be as effective as, or even more effective than, metformin in slowing the progression of type 2 diabetes. Exercise helps improve insulin sensitivity and manage blood glucose levels, which are crucial for diabetes management. Choices B and C are true statements supported by scientific evidence. Choice D is incorrect as A is false, making the statement "none of the above are false" inaccurate.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.