smooth muscle fiber

例句：

1. 1.The smooth muscle in the walls of thearteries contracts and relaxes to regulateblood flow.
   动脉壁中的平滑肌收缩和放松以调节血流。
2. 2. During digestion, the smooth muscle fibers in the stomach contract tohelp break down food.
   在消化过程中，胃中的平滑肌纤维收缩帮助分解食物。
3. 3. The smooth muscle fibers in theskin are responsible for maintaining the body's temperature and protecting against external injuries.
   皮肤中的平滑肌纤维负责维持体温并保护身体免受外部伤害。