Anatomy and Function of the Spine

In addition to providing structure and support for your body, your spine also protects your spinal cord, which contains nerves that extend to every part of your body. For these reasons, a healthy spine is essential for you to enjoy an active lifestyle.

Vertebrae are small bones that encircle and protect the spinal cord. Between the vertebrae are spinal discs, which are like soft cushions that absorb shock when you move and give your spine mobility. Each disc is comprised of a thick outer ring of tissue known as the annulus, which protects the soft inner material called the nucleus.

The vertebrae are connected by facet joints. Each vertebra has four facet joints, and together these joints provide stability and allow for flexibility in the spine. Like the knee, facet joints are synovial joints. This means they contain cartilage and synovial fluid, which prevent friction when two vertebrae, between which the joint is located, move against each other. Facet joints also contain nerves, called medial branches, which carry pain signals to the brain.