Which type of muscle is responsible for involuntary contractions of the heart?

The muscle responsible for involuntary contractions of the heart is cardiac muscle. This type of muscle is unique to the heart and is essential for pumping blood throughout the body. Cardiac muscle is structured to facilitate continuous and rhythmic contractions that are crucial for maintaining circulation. Its cells are interconnected and can transmit electrical impulses quickly, allowing for synchronized heartbeats. This involuntary nature means it operates autonomously, without needing conscious thought, differentiating it from skeletal muscle, which is under voluntary control. The specific characteristics of cardiac muscle, including its striated appearance (which it shares with skeletal muscle) but distinct functions, highlight its critical role in the cardiovascular system.