We have the motor division that consists of only motor neurons also known as epharic neurons and we have the sensory division which consists of only sensory neurons also known as Afaric neurons. Now recall that a motor neuron is basically a neuron that accepts an electrical signal from the central nervous system and sends it away to some type of target organ gland, muscle tissue, and so forth. While the sensory neuron picks up that electrical signal from some type of outside stimulus and sends that electrical signal to the central nervous system where it's integrated as well as processed. Now, the somatic nervous system is responsible for innervating and controlling skeletal muscles, skeletal tissue which basically means the somatic nervous system is ultimately responsible for voluntary movement. So if I want to actually, for example, bend and extend my arm this requires the somatic nervous system. So it's the brain that actually creates or initiates that electrical signal but it's the somatic nervous system that actually extends my arm as we'll see in just a moment.