Which muscle type is responsible for involuntary movements and is found in the heart?

The muscle type that is responsible for involuntary movements and is specifically found in the heart is cardiac muscle. Cardiac muscle cells are unique in their structure and function; they are striated like skeletal muscle but operate involuntarily, meaning they are not consciously controlled. This muscle type allows the heart to contract rhythmically and continuously without fatigue, ensuring that blood is pumped effectively throughout the body. The cells of cardiac muscle are connected by intercalated discs, which facilitate the rapid propagation of electrical signals necessary for coordinated heartbeats. This is essential for maintaining a stable heart rhythm and efficient circulation. The presence of self-exciting pacemaker cells within the cardiac muscle also allows it to initiate contractions automatically, reinforcing its role in involuntary movement.