Now, let's move on to our flat bones. So flat bones are those bones that are relatively thin and which contain a relatively high surface area. Now, these bones can serve two important functions. They can either protect our internal organs and our tissues and they can also serve as attachment points for muscles because of their high surface area. So they contain compact bone on the surface and in the middle, at the center, they contain spongy bone. So what are some examples of flat bones?