A physiologically based model of skeletal growth in the rat

A model of the growing small animal skeleton has been developed. The model accurately reproduces a variety of different kinds of measurements made at different ages in different species, as well as reproducing a precise and detailed series of measurements in the growing guinea pig. Of the multiple mechanisms responsible for transfer of bone-seeking elements from blood to bone and back again, several are quantitatively insignificant on a skeletal scale. Surface (rapid) exchange, diffuse (slow) exchange, and secretion of new bone during growth are the principal determinants of skeletal metabolism. Bone blood flow can probably by satisfactorily modeled as a combination of a basal flow rate plus an increment that is directly proportional to formation rate of new bone.