Developmental physiology of bone

Abstract

As a mineralized connective tissue, bone is both the mineral bank and the mechanical support of the body. Its development influences the development of all the other tissues. Its differentiation takes place early in the fetus and its development continues during the growth period under strict regulation (GH and IGF-1). In adults, bone undergoes a permanent remodelling. The developmental physiology of bone is well known, particularly osteogenesis and long bone growth. The growth-plate, in which chondrocytes proliferate, plays a major role in the growth in length of the bone. It induces the endochondral ossification (transformation of cartilage into bone). The mineralization of the newly synthesized bone matrix constitutes the last stage of bone development  : it is characterized by the precipitation of hydroxyapatite crystals inside the organic matrix enriched in type I collagen. Specific methods have been developed (bone histomorphometry, radioimmunoassay of osteocalcin) to study the effects of regulating factors on bone growth, in order to consider the use of these factors in the future as a possible way of directly modulating bone growth.