Osteoblast, large cell responsible for the synthesis and mineralization of bone during both initial bone formation and later bone remodeling. Osteoblasts form a closely packed sheet on the surface of the bone, from which cellular processes extend through the developing bone.
Osteocytes continue to form bone to some degree, which is important for maintaining the strength and health of the bone matrix. However, osteocytes perform functions that extend far beyond simple maintenance. Bone Remodeling & Repair. Osteocytes comprise 95% of the living cells in adult bone.