The Spine Stack
33 bones in a springy S-curve
Your spine is a tower of 33 bones with a secret: it's not straight. It curves in an S-shape that turns it into a spring that can carry your whole upper body and bend like a willow.
The spine from the side
Real anatomy picture coming soon
Real anatomy photo spot: the S-shaped spine â cervical, thoracic, lumbar, sacrum, coccyx
The tower sections
The 33 vertebrae come in five groups: 7 cervical (neck) vertebrae, 12 thoracic (chest) vertebrae that hold your ribs, 5 big lumbar (lower back) vertebrae that carry the most weight, 5 sacral vertebrae fused into one wedge, and 4 tiny coccyx vertebrae â your tailbone â fused at the very bottom.
Why the S-curve?
If your spine were straight, every jump would slam force up your back like a hammer. Instead, it curves â neck forward, chest backward, lower back forward â turning it into a spring that bends and recoils. Between each vertebra sits a squishy disc (you'll meet them in Lesson 31) that absorbs shock. Together the curves and discs make your spine strong AND bendy.
Mr. Bones says: I'm a fictional skeleton, not a doctor! This is for learning and fun. If anything hurts, stop and tell a grown-up you trust.
