In which order do conduction impulses pass through these structures,causing the heart to contract?
A) SA node,AV node,AV bundle,Purkinje fibers
B) AV node,SA node,AV bundle,Purkinje fibers
C) AV bundle,AV node,SA node,Purkinje fibers
D) Purkinje fibers,SA node,AV node,AV bundle
E) Purkinje fibers,AV node,SA node,AV bundle

Question

Quizplus · Accepted Answer

The normal sequence of conduction impulses in the heart is initiated by the sinoatrial (SA) node, which is the natural pacemaker of the heart. The impulses travel from the SA node to the atrioventricular (AV) node, where they are delayed briefly to allow for complete ventricular filling. From the AV node, the impulses travel down the bundle of His (AV bundle) and then branch into the Purkinje fibers, which spread the impulses rapidly throughout the ventricles and cause them to contract. Therefore, the correct order of conduction impulses is SA node, AV node, AV bundle, and Purkinje fibers, which is represented by option A.

In Which Order Do Conduction Impulses Pass Through These Structures,causing