Which type of muscle is characterized by its involuntary movement and is found in the walls of internal organs?

Smooth muscle is characterized by its involuntary movement and is primarily found in the walls of internal organs such as the intestines, blood vessels, and bladder. It is not under conscious control, which differentiates it from skeletal muscle that is voluntary and striated. Unlike cardiac muscle, which is found only in the heart and also involuntary, smooth muscle lacks striations and has a different structure, allowing it to contract in a smooth and steady manner. Striated muscle, while referring to skeletal and cardiac muscle that exhibit a banded appearance, does not encompass the involuntary aspect that is essential in identifying smooth muscle. Overall, the defining features of smooth muscle include its involuntary nature and location within various internal systems, making it integral to many bodily functions that do not require conscious effort.