Sinoatrial Node Depolarization (SAN Depolarization)

Sinoatrial (SA) node depolarization refers to the process by which specialized pacemaker cells in the SA node of the heart spontaneously generate an action potential, initiating each heartbeat. The SA node is located in the upper back wall of the right atrium and is composed of pacemaker cells that lack a true resting membrane potential. Instead, these cells exhibit a continuous cycle of spontaneous depolarization and repolarization, making them responsible for setting the pace of cardiac rhythm. Key ion channels involved include funny channels (If), T-type Ca²⁺ channels, L-type Ca²⁺ channels, Na⁺-Ca²⁺ exchanger, and potassium channels. The autonomic nervous system tightly regulates SA node automaticity, with sympathetic stimulation increasing heart rate and parasympathetic stimulation decreasing heart rate.

Other names

SA Node Action Potential GenerationSA Node AutomaticityPacemaker PotentialSpontaneous Diastolic Depolarization

N/A - This is a physiological process, not a drug target, but drugs can influence the process.