v/q mismatch with exercise = 1?

[fiasco19]

so v/q is normally .8: 4/5 = .8
since exercise increases cardiac output that seems like it would increase Q causing the mismatch to get farther away from one rather then closer to 1 (example: 4/8 = .5)
what am i missing

also is the reason why O2 helps when v/q is undefined because it goes to parts of the lung where percussion can happen?

---

Members don't see this ad.

 

[Reperfused]

No.

V/Q somewhere in the middle lobe of the lung is 1. (Ideal V/Q: ventilation matches perfusion).

In the apex, V/Q is >1 (because there's more ventilation compared to flow)
In the base, V/Q is <1 (because there's more flow compared to ventilation)

Now, with Exercise (as you mentioned), there's increased CO and vasodilation of the apical capillaries (blood flow in the apex increases, so much so that it becomes close to matching the ventilation). Hence, V/Q (from a value greater than 1) approaches 1.

Just reference FA (FA15 page 606) and it'll be clear. Hope that helps.