[Structure of the walls of osseous lacunae during their formation]

The osseous lacunae formation in the sponge bone has been studied in the human lumbar vertebrae. Conditionally, this process can be divided into a number of stages. During the first-stage, recesses are formed on the surface of the trabeculae. During the second stage, clearly outlined lacunar edges are formed and mineralization of the fundal collagenous structures is completed. During the third stage, the lacunae are closed. A special attention is paid to changes in the structure and spatial architectonics of the fibrillar components of the ground osseous substance forming the lacunae.