The spine is formed by 33 vertebrae along the midline on the human surface. Vertebrae are joined by cartilage called fibrocartilage (symphysis) to form the spine. The average length of the spine is 70 cm in males and 60 cm in females. There are 5 types of vertebrae in the spine.
- Cervical Vertebra: Its number is 7. The first vertebra is called the atlas and the second vertebra is called the axis. The remaining 5 are ideal vertebrae.
- Thoracic Vertebrae: Its number is 12. Each vertebra has facets called capitulum and tuberculum
- Lumbar Vertebra: Its number is 5. Their transverse processes are massive.
- Sacrum Vertebrae: Their number is 5. They join together at age 26 to form the sacrum. It has 4 pairs of 8 pairs of sacrum holes.
- Coccygeal Vertebrae: They are 4 in number. It has 2 articulated cornua on its surface.