BONES HAVE EARS: An Application of Bone Poroelasticity

摘要

The mechanosensory mechanisms in bone include (ⅰ) the cell system that is stimulated by external mechanical loading applied to the bone; (ⅱ) the system that transduces that mechanical loading to a communicable signal; and (ⅲ) the systems that transmit that signal to the effector cells for the maintenance of bone homeostasis and for strain adaptation of the bone structure. The effector cells are the osteoblasts and the osteoclasts. These systems and the mechanisms that they employ have not yet been unambiguously identified. A summary is presented of the current theoretical and experimental evidence suggesting that osteocytes are the principal mechanosensory cells of bone, that they are activated by the effects of fluid flowing through the osteocyte canaliculi, and that the electrically coupled three-dimensional network of osteocytes and lining cells is a communications system for the control of bone homeostasis and structural strain adaptation. A bone poroelastic (BP) model is employed to model the fluid flow behavior caused by the mechanical loading of bone. The similarities of the mechanotransduction system in bone with the mechanotransduction system used by the cells of the hearing system will be described. Both cell systems sense mechanical vibrations in a fluid domain.