Osteoblasts

Lining the trabecular bone are osteoblasts that are synthesizing bone. The initial step in bone synthesis is the formation of osteoid that consists of unmineralized collagen fibers which are produced by osteoblasts. Osteoblasts also secrete proteins and enzymes that catalyze the formation of calcium-phosphate crystals. Over time, these crystals will coat the surface of the collagen fibers to generate fully mineralized bone.