Number of bones in the adult backbone?

there are 63

There are 33 vertebrae in the human spine. (7 cervicals, 12 thoracic, 5 lumbar, 5 that fuse into the sacrum and 4 that fuse into the coccyx.). The sacrum and coccyx are already fused into their...

206

An adult has 206 bones while an infant has from 300 to 350.

When you are born more of your bones are just cartilage. Some bones haven't fused together like in a joint. When some cartilage turns into bone, it fuses with some other bones resulting in less bones.