part_of part of part of capable of capable of respiratory gaseous exchange by respiratory system organ respiration organ SPD:0000428 SCTID:272626006 TGMA:0001247 UBERON:0000171 organ of apparatus respiratorius EMAPA:17607 apparatus respiratorius organ respiratory organ uberon gas exchange organ breathing organ Organ that functions in gaseous exchange between an organism and its environment. In plants, microorganisms, and many small animals, air or water makes direct contact with the organism's cells or tissue fluids, and the processes of diffusion supply the organism with dioxygen (O2) and remove carbon dioxide (CO2). In larger animals the efficiency of gaseous exchange is improved by specialized respiratory organs, such as lungs and gills, which are ventilated by breathing mechanisms. organ of respiratory system respiratory system organ respiratory system