• Distinct from cell or tissue respiration, Respiration is the act of breathing with the lungs and consists of inspiration, or taking ambient air into the lungs, and expiration, or expelling modified air that contains more carbon dioxide than the air taken in.
  NCI Thesaurus
  U.S. National Cancer Institute, 2021
• Inhaling and exhaling air into the body and exchanging oxygen.
  The Omaha System
  Omaha Systems, 2005
• The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2021
• The process by which gases enter the body, including external respiration (breathing), and internal respiration, in which oxygen taken in by the lungs is carried by the blood to tissues and carbon dioxide is removed.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011