Spine Anatomy: Vertebrae, Discs and Nerves
The main regions
The spine is generally divided into the cervical (neck, 7 vertebrae), thoracic (upper/mid back, 12 vertebrae), lumbar (lower back, 5 vertebrae), plus the sacrum and coccyx at the base.
Discs and nerves
Between most vertebrae sit intervertebral discs — a tough outer layer around a softer, gel-like center — that cushion movement and absorb load. Spinal nerves branch out between vertebrae to the rest of the body, which is why problems at a specific spinal level can produce symptoms (numbness, pain) in a related area of the limbs.
Why this matters for common complaints
Understanding which spinal region and structure is involved helps explain why, for example, a lower lumbar disc issue can cause leg symptoms (as in sciatica), while a neck-level problem tends to affect the arms instead.
Key takeaways
- The spine has four main regions: cervical, thoracic, lumbar, plus the sacrum/coccyx.
- Discs cushion movement between vertebrae; nerves branching from the spine explain referred symptoms in the limbs.
- The spinal level involved often explains where symptoms show up in the body.
Sources
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This article is for general educational purposes only and is not medical advice. It does not replace diagnosis, treatment, or personalized recommendations from a licensed healthcare professional. Hands On Health is an independent blog and is not affiliated with any clinic.