What other involuntary muscles exist besides the heart?

There are many other involuntary muscles in the human body besides the heart. Some examples include:

- Smooth muscle: Smooth muscle is found in the walls of hollow organs such as the stomach, intestines, bladder, and blood vessels. It is responsible for controlling the movement of these organs.

- Cardiac muscle: Cardiac muscle is found only in the heart. It is responsible for contracting and relaxing the heart to pump blood.

- Skeletal muscle: Skeletal muscle is attached to bones and is responsible for movement of the body. While skeletal muscles are voluntary muscles, they can also be involuntarily controlled by the nervous system.