Question

The correct sequence for the conducting system is?

1) sinoatrial node, AV bundle, Purkinje fibers, bundle of His
2) sinoatrial node, AV node, AV bundle, Purkinje fibers
3) sinoatrial node, bundle of His, AV bundle, Purkinje fibers
4) sinoatrial node, Purkinje fibers, AV bundle, AV node

Answer 1

The correct sequence for the heart's conducting system is sinoatrial node, AV node, AV bundle, and Purkinje fibers, which corresponds to option 2 in the question provided.

Step-by-step explanation:

The correct sequence for the conducting system of the heart is: sinoatrial node, AV node, AV bundle, and Purkinje fibers. This aligns with option 2 provided in your question. The process starts with the sinoatrial (SA) node initiating an action potential that sweeps across the atria. It then moves to the atrioventricular (AV) node, where there is a delay to allow the atria to complete pumping blood. Following this, the impulse travels through the atrioventricular bundle (also known as the bundle of His) and bundle branches to the Purkinje fibers, which are responsible for ventricular contraction.