An Overview of the Basics
The spine is a complex area of the body comprised of bones, intervertebral discs, muscles, joints and ligaments.
The spine has four primary purposes:
1) to maintain the structure of the trunk,
2) to allow for bodily movement,
3) to protect the nervous system and
4) to act as a shock absorber with a sensory system to provide feedback to the brain through countless specialized nerve endings in spinal tissues.
The spinal column is a series of bones each referred to as a vertebra.With the exception of the top two vertebrae, each pair of vertebrae are separated by an intervertebral disc which serves as a spacer and provides for movement and shock-absorption. The discs provide the spine with flexibility and serve as shock absorbers. The center of the disc is jelly-like and it is contained by tough circular fibers that are anchored to the adjacent bones (vertebrae). The spinal canal is formed by the pedicles and lamina creating a bony ring to protect the spinal cord and roots.
The spine is a column of functional units stacked upon one another. The functional spinal unit is composed of two vertebral bodies separated by a cushion? (the disc). Each functional unit moves independent of one another as well as collectively as part of the vertebral column. Each functional unit contains tissues which have a nerve supply and, therefore, are pain sensitive.
The spine is held in place by supportive muscles, tendons and ligaments.The ligaments are tough, non-elastic bands that hold adjacent bones together and provide stability to the spine. The spine is capable of bearing a significant amount of weight as well as bending and twisting.Spinal movement occurs due to the flexibility of the intervertebral disc, the presence of the spinal facet joints and as the result of muscular contractions.