Spinal anatomy

Last revised by Mohammadtaghi Niknejad on 19 Aug 2022

Spinal anatomy encompasses the anatomy of all osseous and soft tissue structures of the spine, the spinal cord and its supporting structures.

This anatomy section promotes the use of the Terminologia Anatomica, the international standard of anatomical nomenclature. 


The spine is located in the midline posteriorly, extending from the base of the skull to natal cleft, supporting the head, shoulder girdle, rib cage, and attaching to the pelvis. 

It is composed of 24 vertebrae separated by intervertebral discs, with additional sacral and coccygeal segments which are usually but, variably, fused. The vertebrae are grouped together into groups based on similar osteology and regional relations; cervical spine (7 vertebrae), thoracic spine (12 vertebrae), and lumbar spine (5 vertebrae). The sacrum has five fused vertebral segments and the coccyx has a further 3 to 5 vertebral segments. 

The spinal cord descends in the vertebrae within the spinal canal.

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Cases and figures

  • Figure 1: lateral spine anatomy (Gray's illustration)
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  • Case 1: normal MRI
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