The system used for breathing

used in relation to breathing (in and out). Anatomically used to describe the lungs, air pathways and associated muscles. In cell biology used in relation to mitochondrial use of oxygen to produce energy and carbon dioxide waste. (More? Respiratory Notes)

Referring to breathing.

Having to do with respiration, the exchange of oxygen and carbon dioxide. From the Latin re- (again) + spirare (to breathe) = to breathe again.

Of or pertaining to respiration; serving for respiration; as, the respiratory organs; respiratory nerves; the respiratory function; respiratory changes.

Pertaining to respiration; the respiratory system consists of all parts of the body that are involved in respiration including the nose, trachea, and lungs.

pertaining to respiration; "respiratory assistance"