V/Q match is defined as which of the following?

• A. Ventilation-perfusion mismatch, suboptimal gas exchange
• B. Cardiac output and pulmonary perfusion correlation
• C. Ventilation-perfusion match, optimum exchange of oxygen and carbon dioxide
• D. Volume of air moved per minute

Answer: (C)

Understanding V/Q match means recognizing how ventilation (air reaching the alveoli) and perfusion (blood flow in the pulmonary capillaries) work together to exchange gases. When these two processes are well-aligned, oxygen can move into the blood efficiently and carbon dioxide can be expelled, giving the body optimum gas exchange. That’s why the correct wording describes a ventilation-perfusion match as the optimum exchange of oxygen and carbon dioxide.

If ventilation and perfusion aren’t matched, gas exchange becomes suboptimal: too much air without blood flow (dead space) or blood flow without enough air (a shunt) reduce oxygenation and CO2 removal. The other options describe either ventilation alone, perfusion alone, or a general idea of mismatch, which do not capture the concept of the gas-exchange efficiency that comes from V/Q balance.