Vertebral Column

The vertebral column (i.e., the spine) is a segmented bony structure in the body that extends in midline from the cranial base to the pelvis, and then beyond as a coccyx or tail. Typical vertebrae (the individual segments) share bony features that reflect the vertebral column's major functions as a whole, including a body to receive and transmit forces, a neural arch to protect the spinal cord, processes for muscle attachment and leverage, and paired articular processes (zygapophyses) to govern intervertebral movements. Progressing caudally, the size and shape of these bony features changes such that the vertebral column can be subdivided into five regions: cervical, thoracic, lumbar, sacral, and postsacral (coccygeal or caudal). There is considerable morphological variation across primates within these five regions.