Final answer:
The skeletal system, in collaboration with the nervous system, plays a direct role in muscle movement. Together with the muscular system, they form the musculoskeletal system, where muscles attach to bones and generate movement through contraction. The brain's motor system controls voluntary muscle actions, while involuntary movements are regulated by brain stem nuclei.
Step-by-step explanation:
The body system that plays a direct role in moving muscles alongside the muscular system is the skeletal system. The skeletal and muscular systems work together, forming what is commonly known as the musculoskeletal system. Muscles are attached to the bones by tendons, and they span across joints, connecting bone to bone. When muscles contract, they exert force on these bones, generating movement at the joints.
The brain also contributes to muscle movement through systems that control voluntary and involuntary muscle actions. The motor system, which includes the motor cortex, cerebellum, and basal ganglia, coordinates voluntary muscle movement, sending signals down the spinal cord to the muscles. Involuntary movements, such as heart rate and breathing, are controlled by brain stem nuclei. Additionally, the nervous system is responsible for fine-tuning the movements by stimulating specific muscle fibers, such as the fascicles in a multipennate muscle, allowing for more complex and directed movements.