Nerves, which carry information from our brain  to our arms exit to the left and right above and below each cervical vertebra. They are named by the cervical vertebra on top of which they exit. For example, the nerve above the first cervical vertebra is called the first cervical (C1) nerve; the nerve above the second cervical vertebra is called the second cervical nerve (C2), and so on. The only exception to this rule is the eighth cervical (C8) nerve. Because there is no eighth cervical vertebra, the C8 nerve is the name given to the nerves which leave the spinal cord below the last (seventh) cervical vertebra.