Your spine is made of 26 bones known as vertebrae (7 cervical, 12 thoracic, 5 lumbar, the sacrum, and the coccyx). Apart from the top two neck vertebrae, each vertebra is separated by a disc that has a soft, jelly-like center surrounded by a tough outer layer of fibers known as the annulus. Discs, bony structures, ligaments, and strong muscles stabilize the spine.
The spinal cord passes through the bony spine. The spinal cord is composed of nerves leading to and from the brain, and it controls and transmits all muscle movement and sensation for the trunk, arms, and legs. Nerve roots come from the spinal cord and carry electrical impulses to and from muscles, organs, and other structures. These nerve roots can become pinched or irritated by abnormal spine conditions.