The one of the functions occurring at the distal convoluted tubule in the kidney is?

Correct Answer: C

Rationale: DCT reabsorbs water (ADH-dependent) not passive H+/K+ secretion (active), or no Na+ (reabsorbed). This specifies fine-tuning, critical for balance, contrasting with secretion myths.

Correct Answer: B

Rationale: The macula densa resides in the distal tubule within the juxtaglomerular apparatus chemoreceptors/osmoreceptors detect NaCl and osmolarity shifts, signaling renin release by juxtaglomerular cells (e.g., low NaCl triggers). The proximal tubule reabsorbs lacks this role. The Loop of Henle concentrates no renin link. The glomerulus filters unrelated. Its distal location and regulatory function distinguish it, key to tubuloglomerular feedback and blood pressure control, unlike proximal, loop, or filtration sites.

Correct Answer: C

Rationale: Net Filtration Pressure (NFP) = glomerular hydrostatic pressure (HPG) - (oncotic pressure [OPG] + capsular hydrostatic pressure [HPC]): 30 - (25 + 15) = -10 mmHg. Positive 10 mmHg ignores opposition incorrect. Zero miscalculates balance. 5 mmHg underestimates opposition. Negative NFP distinguishes it, indicating no filtration due to shock (e.g., low HPG), key to GFR collapse, unlike positive or neutral errors.

Correct Answer: C

Rationale: ADH-dependent reabsorption occurs in the medullary collecting duct ADH inserts aquaporins, reclaiming water (e.g., concentrates urine). Proximal tubule reabsorbs isotonically ADH-independent. Loop of Henle sets gradient not ADH-driven. Distal tubule starts ADH effect less medullary. Medullary site distinguishes it, key to urine concentration, unlike proximal or loop roles.

Correct Answer: D

Rationale: Erythropoietin is a kidney-made protein produced by peritubular cells (e.g., hypoxia-driven anemia correction). Angiotensin is from angiotensinogen liver, converted renally. Mesangial matrix is structural not protein. Creatinine is muscle waste not synthesized. Erythropoietin's renal origin distinguishes it, key to hematopoiesis, unlike precursors, structures, or wastes.