Which muscle type is found in the walls of hollow organs?

Smooth muscle is the correct answer because it is specifically designed for the involuntary movements required in the walls of hollow organs such as the intestines, bladder, and blood vessels. This muscle type is not striated and operates without conscious control, which is essential for processes like digestion and circulation. Smooth muscle fibers can contract and relax slowly and sustain contractions for extended periods, making them well-suited for their roles in the peristaltic movements that propel contents through organs, as well as regulating the diameter of blood vessels.

Skeletal muscle, while important for voluntary movement, is attached to bones and is involved in locomotion and posture, rather than functioning within the walls of hollow organs. Cardiac muscle is specialized for the heart and is unique for its striated structure and involuntary contractions, but it is confined to the heart and does not relate to other hollow organs. Striated muscle can refer specifically to skeletal and cardiac muscle, so it does not accurately describe the muscle type found in the walls of hollow organs, where smooth muscle predominates.