It is believed that three cells found in bone function in a coordinated manner to maintain healthy bone. Osteoblasts are cells that form new bone and are typically found lining bone surfaces that are undergoing extensive remodeling. Bone-removing cells are large, multinucleated cells called osteoclasts. Osteoclasts break down and remove bone material that is no longer needed or that has been damaged in some way. The third cell type is the osteocyte.
Osteocytes are actually osteoblasts that have become embedded in the newly mineralizing bone tissue.
Many protoplasmic processes, or dendrites, emanating from the cell body characterize osteocytes. These three cell populations, and numerous other biological and biochemical factors, coordinate their activities in a continuous process throughout our lives to maintain a strong, healthy skeletal system. A great deal of effort is currently focusing on why, in some people, bone loses density and becomes brittle. Scientists have put forth several hypotheses to find the answer. Osteocytes may sense strain or deformation within bone tissue.