Which system sends signals to muscles to contract, with increased stimulus leading to more fibers contracting?

The neuromuscular system is integral in facilitating communication between the nervous system and the muscular system, allowing muscles to contract in response to stimuli. When a signal is sent from the nervous system, it triggers the motor neurons that innervate muscle fibers. An increased stimulus leads to a higher frequency of action potentials, which can result in more muscle fibers contracting. This process is essential for activities that require varying degrees of muscle force and coordination.

While the muscular system itself is responsible for the contraction of muscles, and the nervous system sends the signals necessary to initiate this contraction, the neuromuscular system encompasses the relationship between these two systems. It highlights not just the involvement of the nerves and muscles, but also how they work together to achieve coordinated movement in response to stimuli.