Which phase of the ventricular action potential corresponds to rapid Na+ influx?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $25.99Unlock all

Prepare for the Veterinary III CFE Exam with focused study material and interactive quizzes. Use detailed flashcards and multiple choice questions for a comprehensive review. Equip yourself with the knowledge and confidence needed to excel in your study sessions and excel in your assessment!

Multiple Choice

Which phase of the ventricular action potential corresponds to rapid Na+ influx?

Explanation:
The rapid Na+ influx occurs during Phase 0, the upstroke depolarization. In ventricular myocytes, fast voltage-gated Na+ channels open quickly in response to the initial depolarization, allowing a large influx of sodium ions which drives a sharp, steep rise in membrane potential. Phase 1 is the brief initial repolarization from a transient outward K+ current. Phase 2 is the plateau stage where Ca2+ enters the cell through L-type channels, balancing K+ efflux to sustain depolarization. Phase 3 is repolarization driven by continued K+ efflux returning the cell to its resting potential. Phase 0 is specifically the phase that features rapid Na+ influx.

The rapid Na+ influx occurs during Phase 0, the upstroke depolarization. In ventricular myocytes, fast voltage-gated Na+ channels open quickly in response to the initial depolarization, allowing a large influx of sodium ions which drives a sharp, steep rise in membrane potential.

Phase 1 is the brief initial repolarization from a transient outward K+ current. Phase 2 is the plateau stage where Ca2+ enters the cell through L-type channels, balancing K+ efflux to sustain depolarization. Phase 3 is repolarization driven by continued K+ efflux returning the cell to its resting potential. Phase 0 is specifically the phase that features rapid Na+ influx.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy