Which type of muscle tissue is involuntary and found in the heart?

Cardiac muscle is the type of muscle tissue that is involuntary and specifically found in the heart. It is distinct from skeletal muscle, which is under voluntary control and is responsible for movement of the skeleton. Cardiac muscle is unique in its structure, featuring striations similar to skeletal muscle, but it operates autonomously without conscious control. Additionally, cardiac muscle fibers are interconnected, allowing for coordinated contractions that are essential for pumping blood throughout the body. This involuntary nature is crucial for maintaining heart function, ensuring that the heart beats consistently and efficiently to supply oxygen and nutrients.

While nonstriated muscle may refer to smooth muscle, which is also involuntary but found in organs and blood vessels rather than the heart, it is important to recognize that cardiac muscle serves a specific and vital role in the circulatory system. Similarly, visceral muscle typically pertains to the smooth muscle in internal organs, further differentiating it from cardiac muscle. Thus, the defining characteristics and functions of cardiac muscle clarify its correct identification in the context of the question.