Sinoatrial (SA) node

Definition

The sinoatrial (SA) node is a cluster of cells located in the right atrium of the heart that initiates the electrical impulses responsible for each heartbeat. It acts as the natural pacemaker of the heart, setting the rhythm and pace for cardiac activity.

Related terms

Atrioventricular (AV) Node:

This node receives electrical signals from the SA node and provides a pathway for these signals to travel from the atria to the ventricles.

Cardiac Action Potential:

A short-lasting event where electrical membrane potential of a cell rapidly rises and falls, responsible for triggering heart muscles to contract.

Electrocardiogram (ECG or EKG): A test that measures the electrical activity of the heart to show whether or not it is working normally