Which type of muscle is found inside many internal organs of the body?

Smooth muscle is the correct answer because it is specifically designed to operate involuntarily and is found within the walls of various internal organs, such as the stomach, intestines, blood vessels, and bladder. Unlike skeletal muscle, which is under voluntary control and responsible for movements of the skeleton, smooth muscle functions without conscious effort. It plays a critical role in processes such as digestion and circulation by contracting and relaxing to facilitate movement within these organs.

Cardiac muscle, while also involuntary, is found only in the heart and not in other internal organs. Skeletal muscle is primarily attached to bones and does not function within the internal organs. The term "elastic muscle" does not refer to a recognized type of muscle tissue in human anatomy. Therefore, smooth muscle is the type that aligns with the question about the muscle found in many internal organs.