What is lung parenchyma?
Lung parenchyma is the abnormal enlargement of air spaces in the bronchioles. As a result there are two types of emphysema, centrolobular and panlobular. For more information, look here: http://www.thoracic.org/sections/copd/for-health-professionals/pathology-pathogenesis-and-pathophysiology/pathology/lung-parenchyma.