Regarding fat metabolism, which statement is CORRECT?

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: 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.

Correct Answer: C

Rationale: The correct answer is C: Kidney gland. The endocrine system consists of glands that secrete hormones directly into the bloodstream to regulate various bodily functions. The kidney is not a gland; it is an organ responsible for filtering waste from the blood and producing urine. The adrenal gland, thyroid gland, and pituitary gland are all part of the endocrine system as they secrete hormones. In summary, the kidney does not secrete hormones and therefore is not considered a gland in the endocrine system.