Neha Patil (Editor)

Respiration (physiology)

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In physiology, respiration is defined as the movement of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction.


The physiological definition of respiration should not be confused with the biochemical definition, which refers to cellular respiration, a metabolic process by which an organism obtains energy (in the form of ATP) by oxidizing nutrients and releasing waste products. Although physiologic respiration is necessary to sustain cellular respiration and thus life in animals, the processes are distinct: cellular respiration takes place in individual cells of the organism, while physiologic respiration concerns the bulk flow and transport of metabolites between the organism and the external environment.

Gaseous exchange (which in organisms with lungs is called ventilation and includes inhalation and exhalation) is a part of physiologic respiration. Thus, in precise usage, the words breathing and ventilation are hyponyms, not synonyms, of respiration; but this prescription is not consistently followed, even by most health care providers, because the term respiratory rate (RR) is a well-established term in health care, even though it would need to be consistently replaced with ventilation rate if the precise usage were to be followed.

Classifications of respiration

There are several ways to classify the physiology of respiration:

By species

  • Aquatic respiration
  • Buccal pumping
  • Animal respiration
  • By mechanism

  • Respiratory system
  • Breathing
  • Respiration organ
  • Gas exchange
  • Arterial blood gas
  • Control of respiration
  • Apnea
  • By experiments

  • Huff and puff
  • Spirometry
  • Selected ion flow tube mass spectrometry
  • Bell Jar Model Lung
  • Sudden Infant Death Syndrome
  • Myasthenia gravis
  • Asthma
  • Drowning
  • Choking
  • Dyspnea
  • Anaphylaxis
  • Pneumonia
  • Severe acute respiratory syndrome
  • Pulmonary aspiration - Pulmonary edema
  • Death
  • By intensive care and emergency medicine

  • CPR
  • Mechanical ventilation
  • Intubation
  • Iron lung
  • Intensive care medicine
  • Liquid breathing
  • ECMO
  • Oxygen toxicity
  • Medical ventilator
  • Paramedic
  • Life support
  • General anaesthesia
  • Laryngoscope
  • By other medical topics

  • Respiratory therapy
  • Breathing gases
  • Hyperbaric oxygen therapy
  • Hypoxia
  • Gas embolism
  • Decompression sickness
  • Barotrauma
  • Oxygen toxicity
  • Nitrogen narcosis
  • Carbon dioxide poisoning
  • Carbon monoxide poisoning
  • HPNS
  • References

    Respiration (physiology) Wikipedia