Which of the following diuretics inhibits (Na⁺, 2Cl⁻, K⁺) cotransport in the loop of Henle as its primary action?

Correct Answer: C

Rationale: Furosemide, a loop diuretic, inhibits the Na⁺/K⁺/2Cl⁻ cotransporter in the thick ascending limb of the Loop of Henle, blocking reabsorption of these ions, increasing urine output, and reducing blood volume. Thiazides (A) target the DCT, osmotic diuretics (B) work via osmolarity, and carbonic anhydrase inhibitors affect HCO₃⁻, making C correct.

Correct Answer: D

Rationale: Insulin glargine (Lantus) is a long-acting insulin with no peak, providing steady glucose control over 24 hours (D), unlike short-acting insulins. It doesn't cause weight loss (A), isn't restricted to night (B), and lasts far longer than six hours (C), making D the accurate understanding.

Correct Answer: D

Rationale: Urea is indeed formed in the liver from protein metabolism and excreted by the kidneys (D), a correct urinary system function. EPO regulates red, not white, blood cells (A), renin release occurs with low pressure/flow (B), and low creatinine suggests healthy kidneys (C), making D the accurate statement.

Correct Answer: D

Rationale: The thick ascending loop uses a Na/K/2Cl pump to reabsorb salt (A), is impermeable to water/urea (B is false), and furosemide blocks this pump, producing dilute urine (C). A and C are true—salt is pumped out, furosemide dilutes urine—while B is incorrect, making D (A and C are correct) the answer.

Correct Answer: A

Rationale: Aldosterone, high pCO₂, and acidemia boost ammonium (NH₄⁺) excretion (A) in the collecting duct and proximal tubule to excrete H⁺ during acidosis. Aldosterone enhances H⁺ secretion, pCO₂ and acidemia stimulate ammoniagenesis, making A (true) correct over B or added options.