Early detection is important because when abnormal tissue or cancer is found early, it may be easier to treat. By the time symptoms appear, cancer may have begun to spread and be harder to treat. Several screening tests have been shown to detect cancer early and to reduce the chance of dying from that cancer.
I believe it's the last two. "makes the lungs able to fill more completely" and "helps the blood vessels dilate more easily" hope this helps, have an amazing day :)
