So just like our muscle cells, our skeletal muscle cells and cardiac muscle cells consist of individual units known as sarcomeres. The bone also consists of individual units known as osteons. Now, the osteon consists of concentric rings, concentric circles that are known as lamelle. And these lamelle are basically our extracellular matrix that we spoke of earlier. So this is the top view of our osteon. We have these concentric circles we call Lamelli.