Where are the podocytes located and what are they?

Correct Answer: B

Rationale: Podocytes are in the visceral layer of the glomerular capsule modified, branching epithelial cells forming filtration slits (e.g., pedicels) around capillaries. The proximal tubule has cuboidal cells reabsorption, not filtration. The distal tubule includes macula densa sensing, not epithelial. The collecting duct has principal/intercalated cells regulation, not filtration. Podocytes' location and structure distinguish them, key to glomerular filtration barrier, unlike tubular or regulatory cells.

Correct Answer: A

Rationale: Bladder distension from increased intravesical pressure (filling) produces reflex contraction and sphincter relaxation micturition reflex (e.g., parasympathetic). Decreased pressure retains opposite. Osmolarity affects tubules not bladder. Low volume contracts sphincters delays voiding. Reflex response distinguishes it, key to micturition, unlike retention or tubular errors.

Correct Answer: C

Rationale: 20% of plasma entering glomeruli is filtered filtration fraction (e.g., GFR/RPF ≈ 125/625 mL/min). 1% underestimates too small. 99% overstates all plasma isn't filtered. 15% is close standard is 20%. Filtration fraction distinguishes it, key to glomerular dynamics, unlike extreme or near values.

Correct Answer: C

Rationale: Excreted glucose = filtered - Tmax: 200 mg/mL × 125 mL/min = 25,000 mg/min ÷ 100 = 250 mg/min - 200 = 50 mg/min (unit correction assumed). Zero assumes full reabsorption false above Tmax. 25/75 miscalculate filtration incorrect. 50 mg/min distinguishes it, key to glucosuria threshold, unlike total or erroneous values.

Correct Answer: C

Rationale: The thin descending limb is water-permeable osmosis concentrates filtrate (e.g., medullary gradient). Thick ascending is impermeable pumps NaCl. Thin ascending loses salt not water. All permeable is false ascending resists. Water permeability distinguishes thin descending, critical for countercurrent, unlike impermeable or mixed options.