Kidneys in the human body extend from this level

Correct Answer: D

Rationale: Kidneys span T12 to L3 not higher thoracic or extended lumbar. This specifies position, vital for radiology, contrasting with incorrect spans.

Correct Answer: B

Rationale: Tubular secretion is the selective transfer from peritubular capillaries to the tubular lumen removes waste (e.g., H , drugs) into urine. Lumen-to-capillary is reabsorption opposite. Reabsorption conserves e.g., glucose. Filtration occurs at glomerulus not tubular. Selective capillary-to-lumen movement distinguishes it, critical for excretion, unlike reabsorption or filtration processes.

Correct Answer: C

Rationale: Glucose reabsorption is secondary active transport (SGLT) from lumen to cell Na gradient-driven then passive (GLUT) to capillary (e.g., PCT). Passive diffusion alone can't reclaim energy needed. Primary active transport is Na not glucose directly. Full active transport overstates capillary step passive. Dual mechanism distinguishes it, critical for efficient glucose recovery, unlike single-mode errors.

Correct Answer: C

Rationale: Intercalated cells maintain acid-base balance secrete H or HCO₃⁻ in the collecting duct (e.g., pH regulation). Juxtaglomerular cells release renin pressure control. Principal cells manage water/Na ADH/aldosterone. Macula densa senses NaCl GFR feedback. Acid-base role distinguishes intercalated cells, critical for homeostasis, unlike pressure, water, or sensing cells.

Correct Answer: B

Rationale: Principal cells are in connecting tubules (distal/collecting) manage water/Na (e.g., ADH/aldosterone). Intercalated disc is cardiac not renal. Macula densa is distal sensing, not typical connecting. Juxtaglomerular cells are arteriolar renin-focused. Principal cells' presence distinguishes them, key to tubular regulation, unlike misnamed or adjacent cells.