Capillary loops located in the medulla are also known as _________.

Correct Answer: A

Rationale: Vasa recta are medullary capillaries not urea collectors, trigone (bladder), or macula densa (DCT). This specifies countercurrent exchange, key for concentration, contrasting with other terms.

Correct Answer: B

Rationale: Bladder has 3 orifices: 2 ureters (in), 1 urethra (out) not 2, 4, or 5. This counts openings, vital for anatomy, contrasting with miscounts.

Correct Answer: B

Rationale: Principal cells in the collecting tubule regulate water and salt balance ADH increases water permeability (aquaporins), aldosterone boosts Na reabsorption (e.g., ENaC channels). Intercalated cells focus on acid-base H /HCO₃⁻ secretion. Macula densa cells sense NaCl JGA, not balance. Mesangial cells support glomerulus structural. Principal cells' dual role distinguishes them, critical for osmolality and volume homeostasis, unlike pH, sensing, or support cells.

Correct Answer: B

Rationale: Prostaglandin F causes renal vasoconstriction reduces renal blood flow (RBF) and GFR (e.g., opposes vasodilators). Vasodilation (e.g., PGE/I) increases GFR opposite. Renin release is JGA-driven not direct. No effect ignores its role. Constriction's GFR drop distinguishes it, critical for prostaglandin balance, unlike dilation or neutral effects.

Correct Answer: B

Rationale: At 150-300 mL, the bladder triggers the first urge to void stretch receptors signal (e.g., micturition reflex onset). Fullness comes at 300-400 mL escalation. Discomfort at 400-600 mL stronger stretch. Pain at 600-700 mL overdistension. Initial urge distinguishes it, critical for normal voiding cues, unlike later sensations.