Bone Remodeling
Overview of bone remodeling process, cellular players, and its role in skeletal health and adaptation.
Bone remodeling is a continuous physiological process that replaces old or damaged bone with new bone tissue. It maintains bone strength, regulates mineral homeostasis, and adapts to mechanical stress. The process consists of four main phases: activation, resorption, reversal, and formation.
Key cellular components involved include:
Osteoclasts, which resorb bone matrix.
Osteoblasts, which lay down new bone.
Osteocytes, which sense mechanical strain and regulate remodeling.
Lining cells, which cover quiescent bone surfaces.
Bone remodeling is influenced by hormonal signals (e.g., parathyroid hormone, calcitonin, estrogen), mechanical loading, and local cytokines. Imbalances in remodeling can lead to conditions like osteoporosis or delayed fracture healing.