Photomicrograph of an osteoclast on a bone spicule. This Mallory-stained specimen shows a spicule made of calcified cartilage (stained light blue) and a covering of bone tissue (stained dark blue). An osteoclast on the left side of the spicule has resorbed bone tissue and lies in a depression (Howship's lacuna) in the spicule. The light band between the osteoclast and the bone spicule corresponds to the ruffled border of the osteoclast. The arrows on the nongrowing surface indicate cytoplasm of inactive bone lining cells (osteoprogenitor cells). In contrast, bone is being deposited on the opposite side of the spicule, as evidenced by the presence of osteoblasts on this surface and newly formed osteocytes just below the surface of the spicule. x550.
Was this article helpful?