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

Smooth muscle is the correct type found in the walls of hollow organs. This muscle tissue is involuntary and non-striated, meaning that its contractions are not under conscious control and it does not have the banded appearance characteristic of striated muscles. Hollow organs such as the intestines, bladder, and blood vessels rely on smooth muscle to help move substances through them by means of rhythmic contractions, which are often referred to as peristalsis in the digestive tract.

In contrast, skeletal muscle is under voluntary control and is responsible for movement of the skeleton, allowing for actions like walking or lifting objects. Cardiac muscle, while also striated, is found specifically in the heart, where it functions to pump blood throughout the body—with a structure and function distinct from smooth muscle. Striated muscle is a broader term that can include skeletal and cardiac muscle, but does not specifically refer to the muscle type that surrounds hollow organs.