Practice identifying these bones and structure to prepare for your anatomy practical exam. There are flat bones in the skull (occipital, parietal, frontal, nasal, lacrimal, and vomer), the thoracic cage (sternum and ribs), and the pelvis (ilium, ischium, and pubis). The function of flat bones is to protect internal organs such as the brain, heart, and pelvic organs. Flat bones are somewhat flattened, and can provide protection, like a shield; flat bones can also provide large areas of attachment for muscles.