Spine anatomy
The spine is the column of the body, running from below the skull to the pelvis. From the top, seven cervical, twelve thoracic and five lumbar vertebrae are stacked in turn, with the sacrum and coccyx below, and an intervertebral disc sits between the bodies of neighbouring vertebrae. The openings behind the vertebral bodies line up as the vertebral canal, which carries the spinal cord.
Frequently asked questions
How many vertebrae are there?
About 33: seven cervical, twelve thoracic, five lumbar, five sacral and three to five coccygeal. In the adult the sacral and coccygeal vertebrae have each fused into one bone, so the spine is counted as 26 bones.
Why is the spine curved?
Seen from the side, the neck and lower back are convex towards the front and the upper back and sacrum convex towards the back, giving an S shape. The curves help the spine carry the weight of the head and upper body.
How do the thoracic vertebrae connect to the ribs?
Each of the twelve thoracic vertebrae forms joints with a pair of ribs, one on each side. That is why there are twelve of each, and these joints carry the back of the rib cage.
Bones of the spine and back
- Atlas (C1)
- Axis (C2)
- Seventh cervical vertebra (C7)
- First thoracic vertebra (T1)
- Twelfth thoracic vertebra (T12)
- First lumbar vertebra (L1)
- Fifth lumbar vertebra (L5)
- Sacrum
Joints of the spine and back
- Intervertebral joints
- Atlanto-occipital joint
- Atlanto-axial joint
- Costovertebral joints
- Sacroiliac joint
Bone counts
Compare
Other regions
Read more
- The human skeleton in 3D
- BAHI BODY 3D human body
- Chronic Disease Is Systemic Breakdown: chapter summaries
- Blog
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