When you breathe in, your diaphragm contracts, pulling itself flat, and your external intercostal muscles between your ribs contract.

当你吸气时，你的横膈膜收缩，把自己拉平，肋骨之间的外部肋间肌肉收缩。

In addition to the diaphragm, external intercostal muscles are muscles located on the outside of our ribs, and they expand the chest.

除了横膈膜，肋间外肌是位于肋骨外侧的肌肉，它们可以扩张胸部。