- Osteocytes are the most abundant cells in bone, accounting for about 95% of all bone cells. They are mature bone cells that have become trapped within the bone matrix they produce. Osteocytes are star-shaped cells with long, thin cytoplasmic extensions that connect them to neighboring osteocytes and to the blood vessels that run through the bone. Osteocytes help to maintain bone strength and integrity by sensing and responding to changes in the bone environment.

- Osteoblasts are bone-forming cells that are responsible for synthesizing and secreting the bone matrix. They are large, cuboidal cells that line the surfaces of developing bone. Osteoblasts produce a variety of proteins, including collagen type I, osteocalcin, and bone sialoprotein, which are all essential for the formation of new bone.

- Osteoclasts are bone-resorbing cells that are responsible for breaking down and removing old bone tissue. They are large, multinucleated cells that are formed by the fusion of several monocytes/macrophages. Osteoclasts secrete a variety of enzymes, including cathepsin K, matrix metalloproteinases (MMPs), and tartrate-resistant acid phosphatase (TRAP), which all help to break down the bone matrix.