Lumbosacral Spine


(Depending on size)

  • The lumbar spine is composed of large, strong bones which must support the entire weight of the spine and head.
  • The vertebral bodies are separated by fibrous discs which serve as shock absorbers. The discs have a fibrous ring (annulus fibrosis) and a gel-like center (nucleus pulposus).
  • The spinal canal is formed by the pedicles, laminae, and the vertebral bodies and discs; the canal protects the distal portion of the axial nervous system, the cauda equina.
  • The large transverse and spinous processes serve as support for the many paraspinous muscles which allow for the fine movement of the spine.
  • The sacrum is the large, wedge-shaped bone forming the posterior part of the pelvic bowl, and is composed of fused vertebrae.