Illustration of the cranial nerves, 12 sets of nerves connecting the brain to the rest of the body. Cranial nerves are given a roman numeral corresponding to their location in the brain, from anterior (front, I) to posterior (rear, XII). The cranial nerves are broadly classed as either sensory, which detect and respond to external stimuli, motor, which are involved in muscle control, or both. For an unlabelled version see: F041/8449.