Gas exchange question

which of the following has no role in gas exchange in the lungs?

A. autonomic nervous system
B. medulla oblongata
C. oxygen concentration in the blood
D. oxygen concentration of the atmosphere
E. co2 concentration in the atmosphere

Hmm I believe the answer should be B as it is known that the medulla oblongata controls the heart rate and the breathing rate and although it does affect the RATE of gas exchange it doesn’t affect gas exchange itself. However the other options C,D,E do affect gas exchange as it affects the concentration gradient between the lungs (air from atmosphere) and the blood. The autonomic nervous system also affects any involuntary process which has a role in gas exchange.

However an argument could state that oxygen concentration in the LUNGS would have more of a role than oxygen concentration in the BLOOD. As gas exchange happens due to the high CO2 concentration in the blood. However the reason why I believe it is wrong is that the low concentration of oxygen in the blood is what determines that concentration gradient with the lungs so it SHOULD have a role in gas exchange.

Someone clarify with me :)) This is an interesting question


this is also the reason i am confused though I believe medulla is correct here because w/o it controlling the breathing rate with ANS there would be no gas exchange at all:)

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Yess I agree too but It’s hard to see C as the final answer as it also affects gas exchange. All technically affect gas exchange! But the only reason I’m confused with B is because it affects breathing rate but NOT gas exchange since they’re two different things.