Pacemaker

Definition

A pacemaker is a specialized group of cardiac muscle cells in the heart that generates and regulates the electrical impulses responsible for initiating the heartbeat. These cells ensure the heart maintains a regular rhythm, coordinating the contractions of the heart chambers.

Related terms

Sinoatrial (SA) node: The primary pacemaker of the heart located in the right atrium that initiates each heartbeat and sets the pace for the whole heart.

Atrioventricular (AV) node: A cluster of cells situated between the atria and ventricles that delays electrical impulses from the SA node before passing them to the ventricles, ensuring proper timing of contractions.

Electrical conduction system: The network of nodes, cells, and pathways in the heart that generate and transmit electrical impulses, coordinating heartbeat and its rhythm