You have observed an extrasystole in your recording of frog heart contractile activity. Where did it occur?

Question

Quizplus · Accepted Answer

Extrasystoles are premature heartbeats that occur in the heart's chambers either in the atria or the ventricles. When observed during a recording of frog heart contractile activity, an extrasystole occurring during ventricular diastole is most plausible. This is because during diastole, the heart is in a relaxed state, filling with blood, and more susceptible to experiencing an extrasystole. During systole, the heart is contracting, making it less likely for an extrasystole to occur due to the refractory period, which is the short duration after a heartbeat during which the heart cannot be stimulated to contract again.

You Have Observed an Extrasystole in Your Recording of Frog