Patient Care Technician (PCT) AAH Practice Exam

Which part of the heart is responsible for generating the heartbeat?

1. Atrioventricular Node

2. SA Node

3. Bundle of His

4. Purkinje Fibers

The correct answer is: SA Node

The SA Node, or Sinoatrial Node, is known as the natural pacemaker of the heart. It is located in the right atrium and is primarily responsible for initiating the electrical impulses that lead to the contraction of the heart muscles, thereby generating the heartbeat. The electrical signals produced by the SA Node spread through the atria, prompting them to contract and push blood into the ventricles. Other components of the heart's conduction system, like the Atrioventricular Node, Bundle of His, and Purkinje Fibers, play supporting roles. The Atrioventricular Node serves as a gatekeeper that ensures electrical signals from the atria are only sent to the ventricles at an appropriate time, allowing for coordinated contractions. The Bundle of His transmits these impulses from the AV Node down into the ventricles, while the Purkinje Fibers distribute the electrical signals throughout the ventricular muscles, coordinating their contraction. However, the initial heartbeat generation and the rhythm of the heart's pacing originate specifically from the SA Node.