Term Name:	respiration organ
Synonyms:	apparatus respiratorius organ, breathing organ, gas exchange organ, organ of apparatus respiratorius, organ of respiratory system, respiratory organ, respiratory system organ
Definition:	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.
Ontology:	Cell Ontology [UBERON:0000171]