Biology Chemical Coordination SZABMU 2022
PMDC Verified Question 35 of 50
Tetany is caused by _ in blood.
A
Low \(Ca^{2+}\)
B
High \(Ca^{2+}\)
C
Low \(Mg^{2+}\)
D
High \(Mg^{2+}\)
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Low \(Ca^{2+}\)
Concept:

Calcium ions stabilize voltage-gated sodium channels in resting neurons. Proper calcium homeostasis is heavily regulated by the parathyroid gland.

Solution:

  • When parathyroid hormone (PTH) levels drop, it leads to severe hypocalcemia (low blood calcium).


  • Without enough extracellular calcium, sodium channels become overly permeable, causing neurons to depolarize spontaneously. This results in continuous, involuntary muscle spasms known as tetany.


Why other options are incorrect:

High calcium (hypercalcemia) causes sluggish reflexes and muscle weakness, not spasms. Magnesium imbalances also cause issues but are not the primary driver of classical tetany.

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 Chemical Coordination 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