title: Nongravitational terminal nitrogen rise in smokers.
mesh_terms: D000328:Adult; D000402:Airway Obstruction / Q000503:physiopathology; D001285:Atropine / Q000494:pharmacology; D006112:Gravitation; D006371:Helium; D006801:Humans; D008875:Middle Aged; D009584:Nitrogen / Q000502:physiology*; D011187:Posture; D012119:Respiration; D012129:Respiratory Function Tests; D012907:Smoking
chemical_list: D006371:Helium; D001285:Atropine; D009584:Nitrogen