Question

The electrical conduction system of the heart has several components, all of which are instrumental in maintaining polarization, depolarization, and repolarization of cardiac tissue. Which of the conductive structures is known as the pacemaker of the heart?

1) Atrioventricular (AV) node
2) Sinoatrial (SA) node
3) Bundle of His
4) Purkinje fibers

Answer 1

The electrical pacemaker of the heart is the sinoatrial (SA) node, which initiates the heart's electrical impulses for contraction.

Step-by-step explanation:

The pacemaker of the heart is known as the sinoatrial (SA) node. This specialized structure is responsible for initiating the electrical impulses that set the rhythm for cardiac contraction. These electrical signals then propagate through the heart's conduction system in a specific sequence: starting from the SA node, sequentially moving to the atrioventricular (AV) node, passing through the bundle of His, then to the left and right bundle branches, and finally reaching the Purkinje fibers that distribute the impulse throughout the ventricles causing them to contract.