BLOOD CARDIOVASCULAR SYSTEM LYMPHOID ORGANS
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 purpose of this structure is to connect the electrical systems of the atria and the ventricles, providing electrical impedance from the atria and an intrinsic pacemaker in its absence.
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: -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.
Detailed explanation-4: -The delaying an electric impulse through the atrioventricular node (AV node) allows atria to completely empty themselves into the ventricle for contraction before the blood pumps out through ventricles.