has part has part has_part characteristic of has modifier abnormal lung bud morphology absent lung buds lung bud agenesis 2011-03-04T02:59:58Z csmith absent tracheal buds MP:0010907 MPheno.ontology absent primary lung buds absence of the blunt end of the respiratory diverticulum which normally grows ventrally out of the proximal end of the foregut, then extends caudally and divides into two, forming the origins of the bronchial tree abnormal absent lung bud