What is the role of the pulmonary system in supporting cardiovascular responses during exercise?

• A. Decreases ventilation during exercise.
• B. Increased ventilation improves O2 uptake and CO2 removal, supporting gas transport.
• C. The pulmonary system only supports gas exchange at rest.
• D. Ventilation has no impact on matching ventilation and perfusion.

Answer: (B)

During exercise the body's demand for oxygen rises and carbon dioxide production increases. The pulmonary system meets this by increasing ventilation, which raises the alveolar oxygen gradient and speeds up O2 diffusion into the blood while also accelerating CO2 removal. This keeps arterial oxygen levels adequate to support aerobic metabolism in the heart and working muscles and helps maintain blood pH by removing CO2, both of which support cardiovascular performance. In short, better O2 uptake and CO2 clearance through ventilation directly enhances the blood’s ability to deliver oxygen to tissues and keep the cardiovascular system functioning efficiently during exercise. The other statements don’t fit because ventilation does not decrease with exercise, the lungs are active players in exercise, and ventilation helps maintain matching with perfusion rather than being irrelevant to it.