Bone reabsorption. Coloured scanning electron micrograph (SEM) of reabsorption of bone by an osteoclast. The osteoclast is partially seen at upper left, and its cellular processes extend over the underlying bone matrix (lower right). An osteoclast is a type of bone cell that is involved in the breakdown of the bone matrix during bone repair, restructuring and growth. Magnification: x1000 at 6x7cm size.