Question

Summarize the conduction system of the heart. Describe the structures in order, starting with the "pacemaker of the heart."

A. Atrioventricular (AV) node, Bundle of His, Purkinje fibers
B. Purkinje fibers, Bundle of His, Atrioventricular (AV) node
C. Pacemaker, Purkinje fibers, Atrioventricular (AV) node
D. Bundle of His, Atrioventricular (AV) node, Purkinje fibers

Answer 1

The conduction system of the heart includes the sinoatrial (SA) node, internodal pathways, atrioventricular (AV) node, Bundle of His, bundle branches, and Purkinje fibers. The SA node serves as the 'pacemaker of the heart' by initiating the electrical impulses that regulate heart contractions.

Step-by-step explanation:

The conduction system of the heart includes the sinoatrial (SA) node, the internodal pathways, the atrioventricular (AV) node, the atrioventricular bundle (Bundle of His), the right and left bundle branches, and the Purkinje fibers. The pacemaker of the heart is the SA node, which initiates the electrical impulses that regulate the heart's contractions.

The order of the structures in the conduction system is as follows:

1. Sinoatrial (SA) node: initiates the electrical impulses.
2. Internodal pathways: conduct the impulses between the SA node and the AV node.
3. Atrioventricular (AV) node: receives the impulses from the internodal pathways and delays them to allow for the completion of atrial contraction.
4. Atrioventricular bundle (Bundle of His): carries the impulses from the AV node to the ventricles.
5. Right and left bundle branches: branch off from the Bundle of His and distribute the impulses to the respective ventricles.
6. Purkinje fibers: conduct the impulses rapidly through the ventricles, causing them to contract.