The unity of pulmonary circulation and diffusion of gases.
D001775:Blood Circulation; D005740:Gases; D006801:Humans; D008168:Lung / Q000502:physiology*; D011652:Pulmonary Circulation; D012119:Respiration / Q000502:physiology*
D005740:Gases
BLOOD CIRCULATION; LUNGS/physiology; RESPIRATION/physiology