alleryStart learning →What is the trigger for cardiac muscular contraction?
AThe closing of the AV valves
BThe stretch of the pericardium
CThe wave of depolarization
DThe release of chordae tension
Answer & Solution
Correct answer: C. The wave of depolarization
1. The heart couples an electrical event to a mechanical one.
2. The electrical event, the wave of depolarization, is the trigger for muscular contraction.
3. Valve movements are consequences of pressure changes, not triggers.
_Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 19 "The Cardiovascular System: The Heart", section 19.2 Cardiac Muscle and Electrical Activity_
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