Does smooth muscle have striations?

Smooth muscle is characterized by its lack of visible striations when viewed under a microscope. This is in contrast to skeletal and cardiac muscle, which both display striations due to their organized arrangement of actin and myosin filaments in sarcomeres. The absence of these structures in smooth muscle is part of its unique structure that allows for more sustained, involuntary contractions without the need for the precise, rapid movements seen in striated muscles.

Smooth muscle fibers are tapered at both ends and are usually arranged in sheets or layers. This structural formation enables smooth muscle to efficiently contract and relax in a coordinated manner, which is essential for functions such as regulating blood vessel diameter and managing peristalsis in the digestive tract. Overall, understanding the distinct structural characteristics of smooth muscle helps differentiate it from other types of muscle and highlights its functional adaptations.