Which type of neuron carries impulses away from the central nervous system?

• A. Motor neurons
• B. Sensory neurons
• C. Interneurons
• D. Relay neurons

Answer: (A)

Impulses moving away from the central nervous system are carried by motor neurons, the efferent type that sends signals from the brain and spinal cord to muscles or glands to produce a response. This direction of travel is what defines them: they take the command to contract a muscle or stimulate a gland. In contrast, sensory neurons carry impulses from sensory receptors toward the CNS so the body can perceive what's happening, and interneurons (within the CNS) connect and process signals between other neurons. An everyday example is pulling a hand away from a hot surface—the brain sends a motor signal through motor neurons to the arm muscles to contract and withdraw.