What type of neuron is directly responsible for stimulating muscles?

Motor neurons are specifically responsible for stimulating muscles to contract. They transmit signals from the central nervous system to skeletal muscles, enabling movement. When a motor neuron is activated, it releases neurotransmitters at the neuromuscular junction, which then trigger muscle fibers to shorten and produce movement.

In contrast, afferent neurons (or sensory neurons) carry information from sensory receptors towards the central nervous system, ensuring the brain receives input about the body's internal and external environments. Interneurons function primarily within the central nervous system, connecting afferent and efferent neurons and facilitating communication between them, but they do not directly stimulate muscles. Thus, while each type of neuron plays an important role in the nervous system, motor neurons are the ones that directly effectuate muscle contraction.