Osteonic canals, or Haversian canals, are structures in compact bone that contain blood and nerves. Osteonic canals are in the bones of most mammals, amphibians, birds and reptiles. Concentric layers of bone tissue surround each canal. Cement lines form the boundary of each osteon, according to Reference.com.
The osteon is a network that helps facilitate the bone structure by providing nutrients and eliminating metabolic waste. Within each osteon, there are collagen fibers that are parallel to one another but are oblique to the rest of the structure. The density of collagen fiber is lowest at the seams, giving transverse sections of osteons a distinct microscopic appearance. The remnants of osteon, interstitial lamellae, are partially reabsorbed as the body forms new bone tissue.
In humans the process of remodeling bones builds bone mass through the early 20s; however, as an individual ages, the body begins to reabsorb more osteon than it produces, which in a percentage of the population causes a condition known as osteoporosis. This ailment causes bones to become more brittle and subject to fracture.
Both archaeologists and forensic scientists find the information the osteon has to offer useful in identification of the sex and age of the body. These structures reveal the individual's health history, motor development and diet. Since osteon differ by organism, they often reveal the genus and sometimes species of a bone fragment that would otherwise be unidentifiable.