What type of muscle is responsible for involuntary movements, such as those in the heart?

Cardiac muscle is specifically designed for the unique functions of the heart, enabling it to contract involuntarily and rhythmically. This type of muscle tissue is distinct from skeletal muscle, which is under voluntary control and responsible for movements of the skeleton. Unlike smooth muscle, which lines the walls of hollow organs and also operates involuntarily for bodily functions like digestion and blood vessel regulation, cardiac muscle is specialized only for the heart's pumping action. Its cells are connected by intercalated discs that facilitate synchronized contractions, allowing the heart to function effectively as a pump throughout life without conscious effort. This involuntary nature of cardiac muscle is crucial for maintaining consistent blood circulation, supporting the body's demands without direct control from the nervous system.