What type of muscle is described as being involuntary and striated?

Cardiac muscle is characterized as involuntary and striated. It is found exclusively in the heart and is responsible for pumping blood throughout the body. This type of muscle contains striations, which are alternating light and dark bands that are visible under a microscope. These striations result from the organized arrangement of actin and myosin filaments in the muscle fibers, similar to skeletal muscle. However, unlike skeletal muscle, which is under voluntary control, cardiac muscle operates autonomously and is regulated by the autonomic nervous system and hormonal signals.

This involuntary nature allows the heart to function continuously without conscious effort. The striated appearance of cardiac muscle is essential for its function, as it allows for efficient contraction and relaxation, facilitating the heart's rhythm and pumping capacity.