translation.en: The capillaries in the lungs become engorged with blood -- which is caused by the suction -- so the lungs can harden and protect the whole chest cavity from being crushed.
translation.zh: 那么“血移”是个 什么样的生理机制呢？ 当肺里的气压降低后， 肺泡壁会自动充血 这个自我保护机制 使得肺的两壁变得坚固