alleryStart learning →Which structure is known as the pacemaker of the heart?
AThe sinoatrial node
BThe atrioventricular node
CThe bundle of His
DThe Purkinje fibers
Answer & Solution
Correct answer: A. The sinoatrial node
1. Normal cardiac rhythm is established by the sinoatrial node, a specialized clump of myocardial conducting cells.
2. The SA node has the highest inherent rate of depolarization, so it is known as the pacemaker of the heart.
3. The AV node and Purkinje fibers conduct more slowly and follow its lead.
_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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