The spine performs a number of major functions, from supporting the body to transmitting neural signals from the brain to the organs, arms and legs.
It is made up of 24 individual vertebrae (7 cervical, 12 thoracic, 5 lumbar) cushioned by 23 invertebral disks that allow the spine to bend and flex in a number of directions 5 additional sacral vertebrae are fused to form the sacrum and 3-5 vertebrae form the coccyx (also fused).
12. Warwick R, Williams P, ed (1973). Gray's Anatomy (35th ed.). London: Longman