Chromophobe renal cell carcinoma originates from

Correct Answer: C

Rationale: Chromophobe RCC arises from intercalated cells of collecting ducts unique histology (pale cytoplasm). Proximal tubule births clear cell/papillary RCC different lineage. Both tubules isn't specific wrong scope. Principal cells manage sodium unrelated. Intercalated origin distinguishes chromophobe, key to its pathology, unlike proximal or principal sources.

Correct Answer: C

Rationale: Plasma aldosterone-to-renin ratio (ARR) screens primary aldosteronism best high aldosterone, low renin (e.g., adenoma) flags it reliably. Serum potassium (hypokalemia) is suggestive non-specific. Urine aldosterone is diagnostic, not screening cumbersome. Adrenal vein sampling confirms laterality post-screening. ARR's sensitivity distinguishes it, critical for early detection, unlike secondary or invasive tests.

Correct Answer: D

Rationale: Sickle cell disease tops pediatric priapism sickling blocks penile outflow (ischemic), prevalent in affected populations. Idiopathic is less defined residual category. Trauma causes high-flow rarer. Leukemia clogs vessels significant but less common. Sickle cell's dominance distinguishes it, key to pediatric etiology, unlike trauma or hematologic alternatives.

Correct Answer: C

Rationale: Alpha1c isn't a recognized receptor misnomer; Alpha1a, Alpha1b, and Alpha1d mediate LUTS (e.g., BPH). Alpha1a dominates prostate/bladder neck obstruction. Alpha1d affects detrusor irritative. Alpha1b is vascular less LUTS-specific. Non-existent Alpha1c distinguishes it, key to receptor pharmacology, unlike active mediators.

Correct Answer: A

Rationale: The nephron ends at the collecting duct, which drains into the renal papilla, unlike the distal convoluted tubule (preceding), glomerulus (start), or papilla (not part). This distinguishes the nephron's final segment, critical for urine concentration, contrasting with earlier structures.