Cardiac muscle differs from skeletal muscle in that it contracts on a regular basis and lacks voluntary control. The sinoatrial node, which serves as the heart’s pacemaker, regulates the rhythmic contraction of cardiac muscle

The heart is mostly composed of cardiac muscle cells (or myocardium). Two of its most noticeable characteristics are the contractility of the heart, which serves as the foundation for its pumping function, and the rhythmicity of the contraction

To meet the metabolic demands of peripheral tissues such as skeletal muscles, kidneys, brain, skin, liver, heart, and gastrointestinal tract, the cardiac output (the amount of blood pumped by the heart per minute) fluctuates.

Cardiac muscle cells form a highly branched cellular network in the heart. They are composed of myocardial tissue layers that wrap around the chambers of the heart and are linked end to end by intercalated disks