Question

which of the following is the correct sequential path of an action potential in the heart?
multiple choice
sinuatrial node, atrioventricular node, atrioventricular bundle, bundle branches, subendocardial branches (purkinje fibers)
atrioventricular node, sinuatrial node, atrioventricular bundle, bundle branches, subendocardial branches (purkinje fibers)
atrioventricular bundle, atrioventricular node, sinuatrial node, bundle branches, subendocardial branches (purkinje fibers)
subendocardial branches (purkinje fibers), atrioventricular bundle, atrioventricular node, sinuatrial node, bundle branches
atrioventricular node, sinuatrial bundle, atrioventricular node, bundle branches, subendocardial branches (purkinje fibers)

Explanation:

The sinoatrial (SA) node is the natural pacemaker of the heart. It initiates the action potential. The action potential then travels to the atrioventricular (AV) node. From the AV node, it goes through the atrioventricular bundle (bundle of His), then to the bundle branches, and finally to the subendocardial branches (Purkinje fibers) which distribute the impulse throughout the ventricular myocardium.

Answer:

Sinuatrial node, atrioventricular node, atrioventricular bundle, bundle branches, subendocardial branches (Purkinje fibers)