Human Body

Bones, nerves and how the body is put together, in plain language.

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  Bones of the Body: How the 206 Bones of the Skeleton Add Up

  Why adults have 206 bones and babies more, how they split between skull, spine, ribs, arms and legs, the longest and smallest bones, and what bones do besides hold us up.

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  The Central Nervous System: Brain and Spinal Cord Explained

  What the central nervous system is, how the brain and spinal cord are built and protected, how neurons signal, and the numbers worth knowing, from 86 billion neurons to 31 pairs of spinal nerves.