American Academy of Professional Coders (AAPC) Practice Exam

What type of muscle is primarily involved in voluntary movement?

1. Skeletal muscle

2. Cardiac muscle

3. Smooth muscle

4. Appendicular muscle

The correct answer is: Skeletal muscle

Skeletal muscle is the correct answer as it is the type of muscle primarily responsible for voluntary movements. This muscle type is under conscious control, meaning that individuals can deliberately contract and relax these muscles to perform activities like walking, lifting, or any other movements involving the skeletal structure. Skeletal muscles are typically attached to bones by tendons, and their contractions facilitate movement of the bones at joints. Additionally, they exhibit a striated appearance under a microscope due to their organized structure, which is a distinguishing feature. Cardiac muscle, on the other hand, is found only in the heart and is responsible for involuntary movements, specifically the rhythmic contractions that pump blood. Smooth muscle is also involuntary and is found in various internal organs, controlling functions such as digestion and blood vessel contraction. Appendicular muscle is a broader term and could refer to skeletal muscles associated with the limbs but isn't specific enough to indicate voluntary movement alone without the context of skeletal muscle. Thus, skeletal muscle is the clear and correct choice for voluntary movement.