The human skeleton grows steadily from childhood to puberty – around 16 years for girls and 18 for boys – although maturation can be completed between 20 and 24 years.
This development is subject to close endocrine control; in particular, to the action of growth hormone.
Two types of cells intervene, with completely opposite tasks, in the process: while osteoblasts make bones with fibers of collagen and calcium, osteoclasts break down said collagen and release calcium into the bloodstream. When the body grows, the building cells work harder than the destroying cells.
