bone remodeling
Bone remodeling is the process that removes old bone and replaces it with new bone. Osteoclasts attach to bone surfaces and secrete acid and enzymes that dissolve away underlying bone. This resorptive phase takes 3 to 4 weeks. Osteoblasts then migrate into these resorption pits and secrete osteoid, which becomes mineralized with calcium phosphate crystals (hydroxyapatite). This formative and mineralization phase takes 3 months. Osteocytes serve as the mechanoreceptors that sense skeletal stress and send signals, such as sclerostin, to orchestrate the process of bone remodeling in areas of bone that need renewal
