A typical human vertebral column consists of 33 vertebrae at birth, which are divided into five regions:
- 7 cervical vertebrae (neck)
- 12 thoracic vertebrae (upper and mid-back)
- 5 lumbar vertebrae (lower back)
- 5 sacral vertebrae (fused to form the sacrum)
- 4 coccygeal vertebrae (fused to form the coccyx or tailbone)
In adults, the sacral and coccygeal vertebrae are fused, so the number of individual movable vertebrae is usually 24 (7 cervical + 12 thoracic + 5 lumbar), while the sacrum and coccyx form single fused bones
. There can be some variation in the total number of vertebrae, ranging from 32 to 35 in rare cases, due to differences in the number of lumbar, thoracic, or coccygeal vertebrae
. In summary, humans normally have 33 vertebrae at birth, with 24 articulating vertebrae in adulthood plus fused sacral and coccygeal segments.
