Chloride Shift

[MedPR]

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What happens to the chloride that goes into the RBC?

 

[gravitywave]

it hangs out. until RBC gets to the lung, where the whole process reverses itself. Cl- is just in the RBC as a placeholder for charge, so the plasma membrane doesn't get messed up while the RBC makes its way through the venous system.

 

[MedPR]

it hangs out. until RBC gets to the lung, where the whole process reverses itself. Cl- is just in the RBC as a placeholder for charge, so the plasma membrane doesn't get messed up while the RBC makes its way through the venous system.

I see. So when CO2 is "pumped" out into the alveoli, the equilibrium of CO2 and carbonate in the RBC is shifted, leading to carbonate diffusing/being pumped into the RBC? And as carbonate is moved into the RBC, Cl- moves out?

 

[gravitywave]

I see. So when CO2 is "pumped" out into the alveoli, the equilibrium of CO2 and carbonate in the RBC is shifted, leading to carbonate diffusing/being pumped into the RBC? And as carbonate is moved into the RBC, Cl- moves out?

yes. "pump" is simply the concentrations responding to the giant sucking sound of alveolus < capillary < RBC CO2 gradient. carbonic anhydrase should run however the substrate balances tell it to. the bicarb/chloride exchanger doesn't mind either, it goes both ways.