<unk>  tissue is removed by osteoclasts, and then new<unk>  tissue is formed by osteoblasts. Both processes utilize cytokine (TGF-β, IGF) signalling.<unk>  (or<unk>  metabolism) is a lifelong process where mature<unk>  tissue is removed from the skeleton (a process called<unk>  resorption) and new<unk>  tissue is formed (a process called ossification or new<unk>  formation). These processes also control the reshaping or replacement of<unk>  following injuries like fractures but also micro-damage, which occurs during normal activity.<unk>  responds also to functional demands of the mechanical loading. In the first year of life, almost 100% of the skeleton is replaced. In adults,<unk>  proceeds at about 10% per year. An imbalance in the regulation of<unk> 's two sub-processes,<unk>  resorption and<unk>  formation, results in many metabolic<unk>  diseases, such as osteoporosis.
Bone remodeling
Bone resorption
Bone healing
Endochondral ossification
Osteostimulation
Vasculogenesis
Lymphangiogenesis
Neuromodulation 