Normal Bone Physiology 101

Abstract

Adolescence is a critical time for bone growth and development, when a significant amount of bone is deposited, contributing to peak bone mass in adulthood. There is a dynamic interplay between sex steroids, growth hormone, and mechanical loading during adolescence. At the cellular level, this involves the coordination of growth, modeling and remodeling processes by osteoblasts and osteoclasts, mechanosensing by osteocytes, and the seamless synchronization of multiple hormones such as parathyroid hormone (PTH), vitamin D, and fibroblast growth factor (FGF)-23 and cell signaling pathways such as canonical Wnt, Bone Morphogenetic Proteins (BMPs), and receptor activator of nuclear factor kappa B (RANK)/RANK ligand (RANKL).