GROSS ANATOMY
HEART MEDIASTINUM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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AV node
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SA node
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Bundle of His
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Bundle branches
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Detailed explanation-1: -The SA (sinoatrial ) node generates an electrical signal that causes the upper heart chambers (atria) to contract. The signal then passes through the AV (atrioventricular) node to the lower heart chambers (ventricles), causing them to contract, or pump. The SA node is considered the pacemaker of the heart.
Detailed explanation-2: -Both nodes are capable of producing their own impulses. Though under normal conditions, when both are functional, SAN leads and AVN follows. That is, SAN activity determines the rate of heart beat. Hence it can be referred to as pace setter for the heart.
Detailed explanation-3: -The SA node is the pacemaker of the heart and has an intrinsic rate of 60 – 100 bpm.
Detailed explanation-4: -Cells within the sinoatrial (SA) node are the primary pacemaker site within the heart. These cells are characterized as having no true resting potential, but instead generate regular, spontaneous action potentials.
Detailed explanation-5: -Single chamber. One lead attaches to the upper or lower heart chamber. Dual-chamber. Uses two leads, one for the upper and one for the lower chamber. Biventricular pacemakers (used in cardiac resynchronization therapy). 15-Dec-2021