Emphysema pathologically involves beyond the-
Emphysema

Emphysema is a condition of the lung characterized by abnormal permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis.
"Destruction of walls" is necessary to define emphysema. Enlargement of airspaces without destruction of their walls is termed overinflation, for example, the distention of airspaces that occurs in the remaining lung after unilateral pneumonectomy.
Bronchi
Terminal bronchiole
Respiratory bronchiole
Alveolar Sac