The skeleton of an adult, healthy human has 206 bones. However, in the case of children, this number is higher (according to some studies, teens may have up to 356 bones). This is because many points of ossification join later in life – the shafts connect with the epiphyses. On the other hand, older people often fuse the bones of the skull, so their skeleton may have less than 206 bones. Human bones vary greatly in shape and size – the longest of them, i.e. the femur, can be up to half a meter long, and the shortest – the stirrup in the ear – is only 3 millimeters.