Which of the following diuretics is the most potent and cause hypotension * due to hypovolemia from excessive diuresis?

Correct Answer: B

Rationale: Step 1: Furosemide is a loop diuretic, known for its high potency in inhibiting the reabsorption of sodium and chloride in the loop of Henle. Step 2: This leads to significant diuresis, causing hypovolemia and subsequent hypotension. Step 3: Acetazolamide is a carbonic anhydrase inhibitor diuretic, not as potent as loop diuretics. Step 4: Spironolactone is a potassium-sparing diuretic, less likely to cause hypotension due to its mechanism of action. Step 5: Hydrochlorothiazide is a thiazide diuretic, less potent than loop diuretics like furosemide in causing hypovolemia and hypotension.

Correct Answer: A

Rationale: The correct answer is A: ADH plays a key role in the homeostatic filtration apparatus called the process called osmoregulation. ADH, or antidiuretic hormone, regulates water balance by controlling the permeability of the collecting duct in the kidney nephrons. This controls the concentration of urine produced. The other choices, B and C, refer to specific parts of the kidney tubules and are not related to the role of ADH in osmoregulation. Choice D is incomplete and does not provide any relevant information. Therefore, A is the correct choice as it directly relates to the function of ADH in maintaining water balance within the body.

Correct Answer: B

Rationale: The correct answer is B because the antibiotic regimen for acute uncomplicated pyelonephritis should not include gentamycin due to its potential toxicity and nephrotoxicity. The initial use of IV gentamycin is not recommended for uncomplicated pyelonephritis. The combination of gentamycin and amoxicillin is not the standard treatment for this condition. Gentamycin should be reserved for more serious infections. The choice of Augmentin for 7 days orally is also not the standard of care for pyelonephritis. The other choices (A, C, D) are appropriate antibiotic regimens for the corresponding clinical scenarios.

Correct Answer: A

Rationale: The correct answer is A: calcium oxalate. This is because calcium oxalate stones are the most common type of ureteric calculus, accounting for around 75% of cases. They form due to an excess of calcium and oxalate in the urine. Triple phosphate stones (choice B) are more commonly found in the bladder and are associated with urinary tract infections. Urate stones (choice C) are less common and typically seen in patients with gout or acidic urine. Cysteine stones (choice D) are rare and usually seen in patients with a genetic disorder affecting cysteine metabolism.

Correct Answer: C

Rationale: The correct answer is C because the first sign of puberty in boys is typically an enlargement of the testes due to increased testosterone production. This occurs around age 10-14. Choice A is incorrect as puberty usually begins around 10-14 years of age. Choice D is incorrect as penis growth usually starts during puberty, not at 16.