About the spine
The 5 sections of the spine
The cervical spine makes up the neck and has 7 vertebrae.
The thoracic spine has 12 vertebrae which the ribs attach to. The upper ribs splint the spine to the breast bone (the sternum) creating a strong structure to protect the heart and lungs.
The lumbar spine has 5 vertebrae which make the lower back.
The sacrum consists of 5 bones which are fused or stuck together, plus the coccyx which is made up of 4 tiny bones and used to be a tail.
Each vertebra is separated by intervertebral discs which are flexible cartilage discs. These allow movement in the spine and have a shock absorbing or cushioning function as well.
The spine is made up of 33 vertebrae and has 5 sections as illustrated.
Each disc is made up of two parts, a tougher fibrous outside and a central substance called nucleus pulposus. If you suffer a disc bulge, herniation or prolapse, it is the squidgy liquid in the middle which often squeezes out, putting pressure on the nerve roots and causing leg pain.
Each spinal vertebra is attached to the vertebra above and below by the facet joints and each level is known as a mobile segment. Each mobile segment is made up of the vertebral bone above, the intevertebral disc in the middle, the vertebral bone below and facet joints behind. The area behind the bone and the disc and infront of the facet joint is the spinal canal where the nerves pass down.
Facet joint are like any other joint in the body in that have consistr of two bony surface covered by cartilage and fluid between them to act as a lubricant. The facet joint is covered by a capsule.