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. The flat bones are: the
occipital,
parietal,
frontal,
nasal,
lacrimal,
vomer,
hip bone (coxal bone),
sternum,
ribs, and
scapulae. In the
cranial bones, the layers of compact tissue are familiarly known as the tables of the skull; the outer one is thick and tough; the inner is thin, dense, and brittle, and hence is termed the vitreous (glass-like) table.