A bundle of nerve fibres joined together as a tubular sheath that transmits impulses between brain or spinal cord and other body parts is called a nerve. The nerves constitute the peripheral nervous system.
Nerves are of two types in humans:
1. Cranial nerves: They emerge from the brain. There are 12 pairs of cranial nerves.
2. Spinal nerves: They emerge from the spinal’ cord. There are 31 pairs of spinal nerves.
