The cervical nerves consist of eight paired nerves that are a part of the peripheral nervous system. They emerge from the spinal cord through the seven cervical vertebrae. The cervical vertebrae are the spinal bones located just below the skull. Below the cervical vertebrae are the thoracic vertebrae, which are attached to the ribs, so the cervical nerves are located between the ribs and the skull.
The nerves emerge from the spine over the top of each vertebra, except for the eighth, which comes out of the spine under the seventh cervical vertebra. They connect the central nervous system to the body's limbs and organs. The first four cervical nerves split and combine again to make a series of nerves that innervate the back of the head and the neck. The next four cervical nerves, together with the first thoracic nerve, form the brachial plexus. The brachial plexus is a very complicated structure (akin to a busy freeway interchange in Los Angeles), with nerves splitting and recombining to provide nerve functions to the muscles and skin of the hands, arms, shoulders, and chest.