the.com/spines
The architectural genius that lets you stand up, slouch, and regret slouching.
means The flexible column of stacked vertebrae running down a back, protecting the spinal cord and holding the body upright.
from From Latin spina, meaning thorn or backbone — the same root that pricks roses and stiffens courage when someone shows backbone.
Vertebra countTypically 33, fused at the bottom into one tailbone.
Book spinesThe shelved edge borrows the body's load-bearing metaphor.
Defensive dutyCacti and hedgehogs wear spines as armor, not skeleton.