Mechanotransduction and functional response of the skeleton to physical stress: the mechanisms and mechanics of bone adaptation

摘要: The skeleton's primary mechanical function is to provide rigid levers for muscles act against as they hold the body upright in defiance of gravity. Many bones are exposed thousands repetitive loads each day. During growth and development, skeleton optimizes its architecture by subtle adaptations these loads. mechanisms adaptation involve a multistep process cellular mechanotransduction including: mechanocoupling - conversion forces into local signals, such fluid shear stresses, that initiate response bone cells; biochemical coupling transduction signal involving pathways within cell membrane cytoskeleton; cell-to-cell signaling from sensor cells (probably osteocytes lining cells) effector (osteoblasts or osteoclasts) using prostaglandins nitric oxide molecules; either formation resorption cause appropriate architectural changes. These changes tend adjust improve structure prevailing environment. Structural can be predicted, some extent, mathematical formulas derived three fundamental rules: (1) driven dynamic, rather than static, loading; (2) extending loading duration has diminishing effect on further adaptation; (3) accommodate environment, making them less responsive routine customary signals.