part of part of has part has part has_part characteristic of has modifier emphysema emphysema MPheno.ontology an abnormal condition of the lung characterized by permanent enlargement of airspaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis; results in decreased respiratory function including increased air retention and reduced exchange of gases MP:0001958 abnormal respiratory system physiology abnormal pulmonary acinus morphology abnormal increased amount lung pulmonary acinus