Mature bone cells
Maintain bone matrix
Live in 'little lakes' called lacunae
Lacunae are organized in concentric rings called lamellae
Lamellae surround central canal (Haversian canal) which contains blood vessels - these generally run parallel to surface of bone
Narrow passageways called canaliculi connect one lacunae with blood supply in central canal and connect one lacuna with another
Projections of osteocytes extend into canaliculi to communicate with other osteocytes
This repeating pattern found in compact bone describes an osteon (Haversian system) which is the functional unit of compact bone
Note: Spongy bone does not contain osteons
Instead it is organized in struts and arches called trabeculae - these transmit forces to compact bone - make bone strong but light
