Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Cardiomyocytes are specialized muscle cells that make up the cardiac muscle tissue found in the heart. These cells are responsible for contracting and relaxing to pump blood throughout the body.
The myocardium is the thick middle layer of the heart wall composed of cardiac muscle tissue that contracts to pump blood.
Intercalated discs: Intercalated discs are specialized connections between cardiomyocytes that facilitate synchronized contraction of cardiac tissue.
Sinoatrial node (SA node): The SA node is a group of cells located in the right atrium that acts as the heart's natural pacemaker, initiating each heartbeat