Which muscle type is involuntary and found in walls of internal organs?

Smooth muscle is an involuntary muscle type primarily found in the walls of internal organs such as the intestines, blood vessels, and the bladder. This muscle functions automatically without conscious control, facilitating essential processes like digestion and circulation. Unlike skeletal muscle, which is striated and under voluntary control, smooth muscle appears non-striated and is designed for slower and sustained contractions, which are necessary for maintaining functions like peristalsis in the digestive tract. While cardiac muscle, also involuntary, is specific to the heart and has unique striations, it does not serve the same widespread functional role as smooth muscle in various organ systems. Understanding these distinctions helps clarify the specific roles and characteristics of different muscle types in the human body.