آستیون osteons English English wikipedia.org osteons Bone Osteon osteons Bone Osteon osteons osteons osteoni osteon Haversian system osteoni Osteon English English Osteon osteons osteon osteons osteons (or Haversian systems) English en.wikipedia.org osteon circular features are called haversian canals circular features are called haversian canals English آستیون Compact Bone Osteon English English