Diffusion confusion.
D002248:Carbon Monoxide / Q000378:metabolism*; D004058:Diffusion; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000378:metabolism*
D002248:Carbon Monoxide; D010100:Oxygen