What is the yellow pigment in urine called?

Correct Answer: C

Rationale: Urochrome is urine's yellow pigment bilirubin breakdown (e.g., normal color). Hemoglobin is blood abnormal in urine. Urea is waste colorless. Uroglobin isn't a term false. Urochrome's pigment role distinguishes it, critical for urine appearance, unlike blood, waste, or nonexistent options.

Correct Answer: A

Rationale: No ADH makes distal tubules/collecting ducts impermeable to water e.g., no aquaporins, dilute urine. H sensitivity is pH not ADH-related. K /Na swap in PCT is false Na dominant. Hypothalamus/Oâ‚‚ is respiratory unrelated. Impermeability distinguishes it, critical for diuresis, unlike sensitivity or swap errors.

Correct Answer: B

Rationale: Aldosterone increases Na reabsorption e.g., distal tubule ENaC, raises BP. It's adrenal not JGA (renin triggers). K is secreted not reabsorbed. H secretion is separate pH effect indirect. Na reabsorption distinguishes it, key to volume control, unlike origin or ion errors.

Correct Answer: A

Rationale: JG cells are adjacent to macula densa e.g., JGA, secrete renin. Urethra is exit tube not cells. Zona glomerulosa produces aldosterone not JG. Stimulation is angiotensin not cells. Proximity distinguishes it, key to renin release, unlike tubes or hormones.