wMolecular Mechanism of Muscular Contraction The sliding filament model Muscle shortening is due to movement of the actin filament over the myosin filament Reduces the distance between Z-lines 肌肉收缩时肌肉缩短，不是肌丝的缩短而是肌小节的 缩短。 肌肉收缩时，从Z线伸出的细肌丝在某种力量的作 用下向暗带中央滑行而使肌小节缩短。肌肉收缩时肌肉缩短，不是肌丝的缩短而是肌小节的 缩短。 肌肉收缩时，从Z线伸出的细肌丝在某种力量的作 用下向暗带中央滑行而使肌小节缩短。 Molecular Mechanism of Muscular Contraction The sliding filament model Muscle shortening is due to movement of the actin filament over the myosin filament Reduces the distance between Z-lines