Because they merger from the cranium, they are called cranial nerves as opposed to spinal nerves that emerge from the spinal column.
The cranial nerves function as modified spinal nerves. As a group, they have both sensory and motor components: however, individual nerves may be purely sensory, purely motor, or mixed (both motor and sensory).
Twelve pairs of cranial nerves are peripheral nerves of the brain. The other pairs are nerves of the brainstem (and in one case, partially of the cervical spinal cord).
They supply structures of the head and neck and in the case of the vagus nerve, structures of the trunk.
The cranial nerves pass through or into the cranial bones and are numbered I to XII roughly in order from top to bottom.
Their functions are those of the head: some are concerned with awareness of, and communication with, the environment; and some are concerned with sustenance the gut tube and movements associated with it.
Cranial nerves
