Which is NOT part of the normal content of gastric juice?

Correct Answer: D

Rationale: The correct answer is D: amylase. Gastric juice primarily contains hydrochloric acid, pepsinogen, and mucus, but not amylase. Amylase is an enzyme produced in the mouth and pancreas that helps break down carbohydrates, not typically found in gastric juice. HPO42- is a phosphate ion present in gastric juice. Lipase is an enzyme that aids in the digestion of fats and can be found in pancreatic juice, not gastric juice. Mucus is secreted by the stomach lining to protect it from the acidic environment of gastric juice.

Correct Answer: C

Rationale: The correct answer is C because cholesterol is transported from extra-hepatic cells to the liver by high-density lipoproteins (HDLs) in the endogenous pathway. HDLs are responsible for picking up excess cholesterol from peripheral tissues and transporting it back to the liver for excretion. This process helps regulate cholesterol levels in the body. Explanation for other choices: A: Ketone bodies accumulate in DKA due to increased fatty acid breakdown, not a lack of acetyl-CoA substrate. B: Fatty acids are primarily transported in the bloodstream bound to albumin, not lipoprotein complexes. D: Eicosanoids are derived from arachidonic acid, not cholesterol.

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.