Another “Microscopic Mystery”—Solved!

Another “Microscopic Mystery” solved! Yesterday, we posted this photo on our Facebook page.

This is a light microscope photograph of a thin cross section of human compact bone. The whole field shows a single osteon with a Haversian canal in the center (white circular area). The diameter of this osteon would be less than half the thickness of a dime. One would see hundreds of such closely packed osteons in a cross section of a bone like a femur. Osteons are thick walled cylindrical structures in which bone has been laid down in concentric rings starting from the periphery and proceeding towards the center, leaving the Haversian canal. Blood capillaries in the Haversian canal supply the nutrients and gas exchange for the osteocytes (bone cells) buried in lacunae (flattened chambers) in the wall of the osteon. The lacunae are seen as layers of black “spider-like” structures in the wall of the osteon. The buried osteocytes remain in contact with one another by means of slender cell processes that pass through tiny canals (visible as black spider leg like processes around each lacuna.