Reflex arc

• Reflex action

  A automatic and rapid response to stimuli(to protect body), subconscious response which doesn't involve the brain
• Reflex arc

  The nerve path way followed by a reflex action.
• How is reflex arc different to the other types of messages sent to the CNS?

  Generally, the  signal to the effector is sent via the brain, however in a reflex arc it is sent from the spinal cord, for a quicker response.