The osteon, or Haversian system, is the fundamental functional unit of much compact bone. Osteons, roughly cylindrical structures that are typically several millimeters long and around 0.2 mm in diameter.
Each osteon consists of concentric layers, or lamellae, of compact bone tissue that surrounds a central canal, the Haversian canal.
The Haversian canal contains the bone’s nerve and blood supplies.
Osteoblasts form the lamellae sequentially, from the most external inward toward the Haversian canal.
Some of the osteoblasts develop into osteocytes, each living within its own small space also known as the lacuna.
Osteocytes make contact with the cytoplasmic processes of their counterparts via a network of small canals or canaliculi. This network facilitates the exchange of nutrients and metabolic waste.
The space between osteons is occupied by interstitial lamellae, which are the remnants of osteons that were partially resorbed during the process of bone remodeling.
Osteons are connected to each other and the periosteum by oblique channels called Volkmann’s canals.« Back to Glossary Index