The respiratory system is the organ system that is involved in exchange of gases between an organism and its environment.
The respiratory system of a Talaxian is directly linked, in various points, to their spinal cord. (VOY: "Phage")
The Android Lieutenant Commander Data also had a functional respiratory system with the purpose to maintain thermal control of his main systems. Data explained this to Doctor Julian Bashir after he noticed that Data was breathing. (TNG: "Birthright, Part I")
Referenced parts of the system