GENERAL ANATOMY
CARDIOVASCULAR SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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initiate a sinus rhythm
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conduct impulses to the sinoatrial node (SA node)
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initiate ventricular depolarization
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slow down impulses so that the atria can contract to fill the adjacent ventricles with blood
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Detailed explanation-1: -The atrioventricular node (AVN) is a complex structure that performs a variety of functions in the heart. The AVN is primarily an electrical gatekeeper between the atria and ventricles and introduces a delay between atrial and ventricular excitation, allowing for efficient ventricular filling.
Detailed explanation-2: -In the AV node, the impulses are slowed down for a very short time. This allows the atria to contract a fraction of a second before the ventricles. The blood from the atria empties into the ventricles before the ventricles contract.
Detailed explanation-3: -An important aspect of AV node conduction is to introduce a delay between atrial and ventricular excitation to allow time for atrial contraction to complete filling of the ventricles.
Detailed explanation-4: -The AV node is a highly specialized conducting tissue (cardiac, not neural) that slows the impulse conduction considerably (to about 0.05 m/sec), which allows for sufficient time to complete atrial depolarization and contraction prior to ventricular depolarization and contraction.