The secretion of the exocrine pancreas is increased by the following except:

Correct Answer: A

Rationale: The correct answer is A: Vagal stimulation. Vagal stimulation does not directly increase the secretion of the exocrine pancreas. Acetylcholine, Secretin, and CCK are known to stimulate pancreatic secretion through various mechanisms. Acetylcholine acts through muscarinic receptors, Secretin is released in response to acidic chyme in the duodenum, and CCK is released in response to fat and proteins in the duodenum, all leading to increased pancreatic enzyme secretion. Vagal stimulation plays a role in the parasympathetic nervous system but does not directly stimulate pancreatic secretion.

Correct Answer: C

Rationale: Rationale: 1. The mucosal cells of the colon absorb Na to maintain electrolyte balance. 2. Na absorption is crucial for water reabsorption. 3. This process helps regulate stool consistency and prevent dehydration. Summary: A: Incorrect - Bile acid conversion primarily occurs in the liver. B: Incorrect - Bilirubin breakdown mainly occurs in the liver and intestines. D: Incorrect - Aromatic amino acid absorption occurs mainly in the small intestine.

Correct Answer: A

Rationale: The occult fecal blood test detects hidden blood in the stool, which can be an early sign of colonic carcinoma. This test is not specific for malabsorption syndrome, making option B incorrect. Option C is incorrect because the test is primarily used for detecting colonic carcinoma. Option D is incorrect as the test can aid in the discovery of colonic carcinoma.

Correct Answer: A

Rationale: The correct answer is A because secretin hormone is released in response to acidic gastric juice, acting to neutralize the acidity by stimulating pancreatic bicarbonate secretion. Choice B and C are incorrect as secretin does not stimulate stomach mobility or HCL secretion. Therefore, the correct answer is A as it aligns with the function of secretin in regulating pH balance in the digestive system.

Correct Answer: D

Rationale: Correct Answer: D Rationale: 1. Chemotrypsinogen is the inactive precursor of chymotrypsin. 2. Trypsin activates chemotrypsinogen to form active chymotrypsin. 3. This activation occurs in the small intestine, enabling protein digestion. Summary: A: Trypsin is secreted as an inactive zymogen, not in the active form. B: CCK stimulates enzyme secretion, not bicarbonate. C: Secretin mainly stimulates bicarbonate secretion, not enzymes.