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Spine

The spine (backbone) is composed of 33 interlocking bones called vertebrae that are separated by soft, compressible discs and supported by many different ligaments and muscles. It is divided into five segments: cervical (neck), thoracic (upper and middle back), lumbar (lower back), sacrum (pelvis), and coccyx (tailbone). In each segment, the vertebrae are numbered from top to bottom. For example, a C3 is the third vertebra in the neck area, while a T6 is the sixth vertebra in the thoracic area.

The vertebrae in the spine normally form 3 curves. These curves allow the spine to absorb shock as you move.

Primary Medical Reviewer William M. Green, MD
- Emergency Medicine
Primary Medical Reviewer Kathleen Romito, MD
- Family Medicine
Specialist Medical Reviewer Kathie Hummel-Berry, PT, PhD
- Physical Therapy
Specialist Medical Reviewer Robert B. Keller, MD
- Orthopedics
Last Updated February 15, 2006

WebMD Medical Reference from Healthwise

Last Updated: February 15, 2006
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