CO₂ dissociation curve

Carbon dioxide content (the sum of the amount of CO₂ bound to hemoglobin and dissolved in plasma) is plotted as a function of the PaCO₂ in the blood. Note that the relationship is relatively linear over the physiological range of PaCO₂.

Because of the relatively linear shape of the PaCO₂ versus CO₂ content graph, hyperventilating a normal unit and reducing the PaCO₂ in the blood from that unit can compensate for the elevated CO₂ content of the blood leaving a poorly ventilated unit.