How does respiration differ from ventilation?

How does respiration differ from ventilation?

• A. Respiration is gas exchange, whereas ventilation is the simple movement of air between the lungs and the environment.
• B. Respiration is diaphragmatic contraction; ventilation is oxygen transport by blood.
• C. Respiration is oxygen transport; ventilation is carbon dioxide removal.
• D. Respiration is exhalation only; ventilation is inhalation only.

Answer: (A)

Ventilation is the mechanical movement of air into and out of the lungs, while respiration refers to the gas exchange that uses that air—oxygen moving from the air into the blood and carbon dioxide moving from the blood into the air to be exhaled, plus the cellular use of oxygen to produce energy. The best choice captures this distinction: respiration is gas exchange, whereas ventilation is simply the movement of air between the environment and the lungs. The other statements mix up these roles—for example, diaphragmatic action is part of ventilation, not respiration; oxygen transport by blood and carbon dioxide removal are aspects of gas exchange and circulation, not ventilation alone; and respiration is not limited to exhalation, nor is ventilation limited to inhalation.

Ventilation is the mechanical movement of air into and out of the lungs, while respiration refers to the gas exchange that uses that air—oxygen moving from the air into the blood and carbon dioxide moving from the blood into the air to be exhaled, plus the cellular use of oxygen to produce energy. The best choice captures this distinction: respiration is gas exchange, whereas ventilation is simply the movement of air between the environment and the lungs. The other statements mix up these roles—for example, diaphragmatic action is part of ventilation, not respiration; oxygen transport by blood and carbon dioxide removal are aspects of gas exchange and circulation, not ventilation alone; and respiration is not limited to exhalation, nor is ventilation limited to inhalation.