Question

In the sequence of electrical conduction in the heart, what is the correct order of the structures listed?

A) Purkinje fibers, AV Node, Bundle of Hiss, SA Node, Internodal Pathways
B) SA Node, Internodal Pathways, AV Node, Bundle of Hiss, Purkinje fibers
C) AV Node, SA Node, Purkinje fibers, Bundle of Hiss, Internodal Pathways
D) Bundle of Hiss, SA Node, Internodal Pathways, AV Node, Purkinje fibers

Answer 1

The correct sequence of electrical conduction in the heart is: SA Node, Internodal Pathways, AV Node, Bundle of His, Purkinje fibers, matching option B.

Step-by-step explanation:

In the sequence of electrical conduction in the heart, the correct order of the structures listed for normal heart rhythm is as follows:

1. Sinoatrial (SA) Node
2. Internodal Pathways
3. Atrioventricular (AV) Node
4. Bundle of His (Atrioventricular Bundle)
5. Purkinje fibers

This sequence starts with the SA node, which initiates the electrical impulse, and then the signal travels through the internodal pathways to the AV node.
There is a brief delay here to allow the atria to contract fully. Next, the signal continues to the Bundle of His, which branches into the left and right bundle branches and then to the Purkinje fibers, which spread the impulse throughout the ventricles for coordinated contraction of the heart muscle.

Therefore, the correct choice is B) SA Node, Internodal Pathways, AV Node, Bundle of His, Purkinje fibers.