Spine
What is the spine?
Your spine, or backbone, is your body's central support structure. It connects different parts of your musculoskeletal system. Your spine helps you sit, stand, walk, twist and bend. Back injuries, spinal cord conditions and other problems can damage the spine and cause back pain.
A healthy spine has three natural curves that make an S-shape. These curves absorb shocks to your body and protect your spine from injury. Many different parts make up your spine:
Vertebrae:The spine has 33 stacked vertebrae (small bones) that form the spinal canal. The spinal canal is a tunnel that houses the spinal cord and nerves, protecting them from injury. Most vertebrae move to allow for a range of motion. The lowest vertebrae (sacrum and coccyx) are fused together and don’t move.
Facet joints:These spinal joints have cartilage (a slippery connective tissue) that allows vertebrae to slide against each other. Facet joints let you twist and turn, and they provide flexibility and stability. These joints can develop arthritis and cause back pain or neck pain.
Intervertebral disks:These flat, round cushions sit between the vertebrae and act as the spine’s shock absorbers. Each disk has a soft, gel-like center (the nucleus pulposus) surrounded by a flexible outer ring (the annulus). Intervertebral disks are under constant pressure. A herniated disk can tear, allowing some of the nucleus’ gel substance to leak out. Herniated disks (also called bulging, slipped or ruptured disks) can be painful.
