In replying to a patient's questions about the seriousness of her chronic kidney disease, the nurse knows that the stage of chronic kidney disease is based on

Correct Answer: B

Rationale: Chronic kidney disease staging relies on glomerular filtration rate (GFR), reflecting filtration capacity not urine output (variable), creatinine/urea (indicators, not staging), or mental status (symptom). This distinguishes GFR's diagnostic primacy, critical for CKD progression tracking, contrasting with secondary markers.

Correct Answer: C

Rationale: Distal convoluted tubules (DCT) lack a brush border (proximal feature), have indistinct boundaries due to fewer microvilli, and show basal striations not wide diameter. This distinguishes DCT histology, key for reabsorption/secretion roles, contrasting with proximal traits.

Correct Answer: D

Rationale: Mesangial cells contract to reduce GFR area and phagocytose debris not produce systemic angiotensin II (juxtaglomerular cells). 'A and C' are true, distinguishing mesangial roles, critical for filtration regulation, contrasting with renin-angiotensin.

Correct Answer: B

Rationale: Renal threshold (~180 mg/dL or mg%) is the plasma glucose level where reabsorption saturates, spilling into urine not rate (mg/min) or higher values. This distinguishes glucose homeostasis, critical for diabetes, contrasting with saturation definitions.

Correct Answer: B

Rationale: Renin comes from juxtaglomerular cells (afferent arteriole), not efferent macula densa (DCT), fenestrated capillaries (glomerulus), and collecting tubules (rays) are correct. This distinguishes renin's source, key for RAAS, contrasting with vascular misplacement.