Bone structure and metabolism

The bones of the skeleton provide mechanical support for joints, tendons and ligaments, protect vital organs from damage, and act as a reservoir for calcium and phosphate in the preservation of normal mineral homoeostasis. Bone is a dynamic tissue that undergoes renewal and repair throughout life through the process of bone remodelling. Most diseases of bone occur as the result of abnormalities in the remodelling process that compromise the architecture, structure or mechanical strength of bone, leading to clinical symptoms, such as pain, deformity and fracture, and abnormalities of calcium and phosphate homoeostasis. This article reviews key aspects of bone development, anatomy and composition, and the cellular and molecular mechanisms responsible for regulation of bone remodelling.