Multiple spine and neck joints

I noticed in unity 4.0 I can only select one joint out of mine ~4 in neck and spine. How could I add more if it is possible ? Or for game characters unity 3d setup is as is and not changeable ? I need some neck and spine parts to move with precision, so I didn't used just one joint. You can see in image below, what I problems get because of single joints at each part.