Cortical bone, synonymous with
compact bone, is one of the two types of
osseous tissue that form
bones. Cortical bone facilitates bone's main functions: to support the whole body, protect organs, provide levers for movement, and store and release chemical elements, mainly calcium. As its name implies, cortical bone forms the
cortex, or outer shell, of most bones. Again, as its name implies, compact bone is much denser than
cancellous bone, which is the other type of osseous tissue. Furthermore, it is harder, stronger and stiffer than cancellous bone. Cortical bone contributes about 80% of the weight of a human skeleton. The primary anatomical and functional unit of cortical bone is the
osteon.