College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which statement is correct regarding the contraction length and speed of smooth muscle compared to skeletal muscle?

1. Skeletal muscle takes longer to contract and has longer contraction duration

2. Both types of muscle contract at the same speed

3. Smooth muscle takes longer to begin contraction and contracts for a longer period

4. Skeletal muscle has more prolonged contractions than smooth muscle

The correct answer is: Smooth muscle takes longer to begin contraction and contracts for a longer period

The accurate statement is that smooth muscle takes longer to begin contraction and contracts for a longer period compared to skeletal muscle. Smooth muscle has a slower rate of contraction initiation due to its physiological properties, including a different action potential duration and a reliance on calcium ions entering the muscle fibers. This process typically requires more time than in skeletal muscle, which is characterized by its fast-twitch fibers that allow for quick and powerful contractions. Additionally, once smooth muscle is activated, it also maintains contractions for extended durations. This is particularly important for functions such as maintaining vascular tone or the contraction of the gastrointestinal tract, where sustained contractions are necessary for proper function. In contrast, skeletal muscle contractions are typically shorter and more forceful, allowing for rapid movements and quick bursts of energy. Understanding these differences is crucial for recognizing how the two muscle types serve different functions in the body, aligning with their structural and functional characteristics.