musculus rectovaginalis

例句：

1. 1.The muscle of the diaphragm is responsible for breathing.
   膈肌的肌肉负责呼吸。
2. 2. The muscle relaxes when we lie down.
   当我们躺下时，肌肉会放松。
3. 3. Muscle pain can be caused by overuse or injury.
   肌肉疼痛可能是过度使用或受伤引起的。