We've all heard about someone who's torn an ACL, but do we really know what that means?
Can you bend your thumb backwards until it touches your wrist? If you join your hands behind your back, can you lift them over your head without letting go?
There are some important differences between horns and antlers.
Bones are not just for structural support, but are also dynamic organs, containing active living cells and with blood vessels and nerves running through them.