Flat bones are bones whose principal function is either extensive protection or the provision of broad surfaces for muscular attachment. These bones are expanded into broad, flat plates, as in the cranium (skull), the ilium (pelvis), sternum and the rib cage.

Are cranial bones flat or irregular?

Flat bones are thin, flattened, and usually curved. Most of the bones of the cranium are flat bones.

What are cranial bones?

The eight bones of the cranium form the “vault” that encloses the brain. They include the frontal, parietal, occipital, temporal, sphenoid and ethmoid bones.