Cardiac muscle is distinguished from skeletal muscle by its regular contractions and lack of voluntary control. The sinoatrial node of the heart, which functions as the heart’s pacemaker, controls the rhythmic contraction of cardiac muscle.

The heart is primarily made up of cardiac muscle cells (or myocardium). The contractility of the heart, which is the foundation for its pumping function, and the rhythmicity of the contraction are two of its most notable qualities.

The cardiac output (the volume of blood pumped by the heart per minute) changes to fulfill the metabolic needs of peripheral tissues like skeletal muscles, kidneys, brain, skin, liver, heart, and gastrointestinal system.

In the heart, cardiac muscle cells form a highly branching cellular network. They are structured into layers of myocardial tissue that wrap around the chambers of the heart and are joined end to end by intercalated disks.

Individual cardiac muscle cells contract, producing force and shortening in these bands of muscle, resulting in a reduction in heart chamber size and blood ejection into the pulmonary and systemic veins.