The spine is made up of many individual bones called vertebrae, joined together by muscles and ligaments. Flat, soft intervertebral discs separate and cushion each vertebra from the next. Because the vertebrae are separate, the spine is flexible and can bend. Together the vertebrae, discs, muscles, and ligaments make up the vertebral column or spine. Different regions of the spine are named differently. The cervical spine refers to the neck, the thoracic spine to the chest, and the lumbar and sacral spines to the low back.
The cervical bones - the vertebrae - are smaller in size when compared to other spinal vertebrae. The purpose of the cervical spine is to contain and protect the spinal cord, support the skull, and enable diverse head movement (e.g., rotate side to side, bend forward and backward).
A complex system of ligaments, tendons, and muscles help to support and stabilize the cervical spine. Ligaments work to prevent excessive movement that could result in serious injury. Muscles also help to provide spinal balance and stability, and enable movement. Muscles contract and relax in response to nerve impulses originating in the brain. Some muscles work in pairs or as antagonists. This means when a muscle contracts, the opposing muscle relaxes. There are different types of muscle: forward flexors, lateral flexors, rotators, and extensors.