Which is NOT an action of CCK?

Correct Answer: B

Rationale: The correct answer is B: increased gastric motility and emptying. CCK, or cholecystokinin, is a hormone released by the small intestine in response to the presence of fats. Its main actions include stimulating gallbladder contraction (A) to release bile for fat digestion, triggering the secretion of pancreatic juice (D) containing digestive enzymes, and inhibiting gastric motility and emptying. Therefore, increased gastric motility and emptying (choice B) is NOT an action of CCK. This is because CCK acts to slow down gastric emptying to allow for effective digestion of fats in the small intestine. Choices A, C, and D are all correct actions of CCK based on its role in the digestive process.

Correct Answer: A

Rationale: The correct answer is A: ornithine. Ornithine is not a standard amino acid found in protein structures but is involved in the urea cycle. Arginine, valine, and aspartic acid are all standard amino acids that are commonly found in proteins. Ornithine is not incorporated into proteins during translation, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: nervous system. The endocrine system regulates body functions through hormones, while the nervous system controls body functions through electrical impulses. Both systems coordinate and control various bodily functions. The skeletal system (A) supports and protects the body, the immune system (B) defends against pathogens, and the respiratory system (D) facilitates gas exchange. However, these systems do not primarily regulate and control bodily functions like the endocrine and nervous systems.

Correct Answer: C

Rationale: The correct answer is C: 2. The posterior pituitary produces two hormones: oxytocin and vasopressin. Oxytocin is involved in childbirth and breastfeeding, while vasopressin helps regulate water balance in the body. Option A is incorrect because the posterior pituitary does produce hormones. Option B is incorrect as there are two hormones produced, not just one. Option D is incorrect as the posterior pituitary does not produce six hormones. In summary, the posterior pituitary gland produces two hormones, making option C the correct answer.

Correct Answer: B

Rationale: The correct answer is B (3 litres). The average adult human stomach secretes about 2-3 liters of gastric juice per day. This amount is necessary for the effective digestion of food, as gastric juice contains hydrochloric acid, enzymes, and mucus. Option A (1.5 litres) is too low for daily gastric juice secretion. Option C (4 litres) is too high and could lead to hypersecretion or other digestive issues. Option D is incomplete and does not provide a valid answer. Therefore, option B is the most accurate in reflecting the average daily secretion of gastric juice.