HESI Registered Nurse EXIT Practice Exam

Which sequence demonstrates the normal electrical pathway of an impulse through the heart?

1. AV node, SA node, Bundle of His, Purkinje fibers

2. Purkinje fibers, SA node, AV node, Bundle of His

3. Bundle of His, Purkinje fibers, SA node, AV node

4. SA node, AV node, Bundle of His, Purkinje fibers

The correct answer is: SA node, AV node, Bundle of His, Purkinje fibers

The normal electrical pathway of an impulse through the heart begins with the sinoatrial (SA) node, which is known as the heart's natural pacemaker. This is where the electrical impulse is generated, triggering the contraction of the atria. From the SA node, the impulse travels to the atrioventricular (AV) node. The AV node serves as a critical delay mechanism, allowing the atria to fully contract and fill the ventricles with blood before the ventricles contract. Following the AV node, the electrical signal moves to the Bundle of His, which is a pathway of fibers that transmits the impulse into the ventricles. Finally, the impulse spreads through the Purkinje fibers, which are responsible for conducting the impulse quickly throughout the ventricles, ensuring a coordinated contraction. This sequence of activation is essential for maintaining an effective and efficient heart rhythm, allowing for proper blood flow throughout the body. The sequence presented highlights the crucial functions each part of the conduction system plays in the sequence of heart contractions, ensuring that the heart beats in a synchronized manner.