What is the main characteristic of smooth muscles?

The main characteristic of smooth muscles is that they are involuntary and found in internal organs. This muscle type plays a crucial role in various bodily functions such as digestion, blood vessel regulation, and respiratory processes. Unlike skeletal muscles, which are under voluntary control and have a striped appearance due to their striations, smooth muscles do not show such striations and operate automatically without conscious effort. They are primarily located in the walls of hollow internal organs like the intestines, blood vessels, and bladder, helping to facilitate processes such as peristalsis in the digestive system and the regulation of blood pressure. Therefore, the distinct involuntary nature of smooth muscle is essential for maintaining many critical physiological processes.