Gravity-depende sequential emptying of lung regions.
D006112:Gravitation; D006801:Humans; D008168:Lung / Q000502:physiology*; D009584:Nitrogen; D011650:Pulmonary Alveoli / Q000502:physiology; D013147:Spirometry; D014978:Xenon
D014978:Xenon; D009584:Nitrogen