Photomicrograph of a growing bone spicule stained with Mallory-Azan. Osteocytes are embedded within the bone matrix of the spicule, which is stained dark blue. These cells are metabolically active, laying down the unmineralized bone matrix (osteoid). A number of osteoblasts are aligned on the right side of the spicule. Between these cells and the calcified bone spicule is a thin, light-blue-stained layer of osteoid. This is the uncalcified matrix material produced by the osteoblasts. One of the cells (arrow) has virtually surrounded itself by its osteoid product; thus it can now be called an osteocyte. On the left side of the spicule, the nongrowing part, are inactive osteoblasts. The cells exhibit flattened nuclei and attenuated cytoplasm. x550.
Was this article helpful?