Biology Homeostasis PMDC Conceptual Practice
PMDC Verified Question 56 of 99
During conditions of severe dehydration, maximum renal water reabsorption and urine concentration depend primarily on the function of:
A
Juxtamedullary nephrons
B
Cortical nephrons
C
Glomerular capsules
D
Cortical interstitial tissue
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Juxtamedullary nephrons
Concept: Specialized role of juxtamedullary nephrons.

Solution: Juxtamedullary nephrons generate and maintain the deep medullary osmotic gradient via their long loops of Henle, enabling maximum osmotic water extraction from collecting ducts during dehydration.

Why other options are incorrect:
  • Option B: Cortical nephrons have short loops that cannot generate the deep hyperosmotic gradient required for maximum urine concentration.

  • Option C & Option D: Glomerular capsules perform filtration; cortical interstitium is isotonic to normal plasma (~300 mOsm/L).

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Previous Question All Homeostasis MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App