Which chamber houses the Sinoatrial (SA) node?

Which chamber houses the Sinoatrial (SA) node?

• A. Right Atrium
• B. Left Atrium
• C. Right Ventricle
• D. Left Ventricle

Answer: (A)

The main idea here is where the heart’s natural pacemaker sits. The Sinoatrial (SA) node is located in the wall of the right atrium, near the opening of the superior vena cava. This strategic spot lets its pacemaker cells generate impulses that rapidly spread across the atria to trigger atrial contraction, and then pass the signal to the AV node and onward to the ventricles. The other chambers listed do not house the SA node—the left atrium and left ventricle don’t contain the primary pacemaker, and while the AV node is also part of the conduction system, it resides in the right atrium but separate from the SA node. So, the chamber housing the SA node is the right atrium.

The main idea here is where the heart’s natural pacemaker sits. The Sinoatrial (SA) node is located in the wall of the right atrium, near the opening of the superior vena cava. This strategic spot lets its pacemaker cells generate impulses that rapidly spread across the atria to trigger atrial contraction, and then pass the signal to the AV node and onward to the ventricles. The other chambers listed do not house the SA node—the left atrium and left ventricle don’t contain the primary pacemaker, and while the AV node is also part of the conduction system, it resides in the right atrium but separate from the SA node. So, the chamber housing the SA node is the right atrium.