Hemoglobin and hyperventilation

[ysk1]

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I'm aware that the urge to breath results from high CO2 concentrations in the blood, and there are no physiological sensors of blood pO2. Will hyperventilation (breathing rapidly and deeply for several minutes) increase the blood's O2 content? I think it will, because you take in as much O2 in a little time. What do you guys think?

 

[armybound]

yes

pO2 increases, pCO2 decreases, pH increases.

 

[olemissbabydoc]

other important terms to know/ apply:

alkalosis: situation described above

acidosis: pCO2 increases, pO2 decreases, pH decreases

 

[blastula]

I'm aware that the urge to breath results from high CO2 concentrations in the blood, and there are no physiological sensors of blood pO2. Will hyperventilation (breathing rapidly and deeply for several minutes) increase the blood's O2 content? I think it will, because you take in as much O2 in a little time. What do you guys think?

This will result in a left shift of the HbO2 dissociation curve increasing Hb's affinity for oxygen, decreasing [CO2] which decreases [H+] raising pH. I have found it helpful to refer to the curve for questions involving Hb, [O2], [CO2], [H+], change in temperature.

 

[coffeebythelake]

I'm aware that the urge to breath results from high CO2 concentrations in the blood, and there are no physiological sensors of blood pO2. Will hyperventilation (breathing rapidly and deeply for several minutes) increase the blood's O2 content? I think it will, because you take in as much O2 in a little time. What do you guys think?

There are sensors for blood O2, located in the aortic arch and carotid bodies. The effect under normal circumstances is weak. It is primarily used to prevent excessive compensatory hypoventilation in response to metabolic alkalemia.

 

[werd]

agree with the immediately preceeding post. also, hyperventilation will only slightly increase the amount of oxygen in the blood. once hemoglobin is 100% saturated in the lungs, there's nothing more to carry the oxygen... O2 is slightly soluble in blood and some dissolves into it without being carried by Hb, but this contribution is very minor compared to the oxygen content in Hb.

 

[iblunk]

I agree with the two above posts. Carotid bodies and aortic bodies do sense PO2 levels, but most of the control lies in C02.

As for the O2 levels, Im not entirely sure about this next paragraph but i think it is correct. Though alveolar P02 will increase if youre breathing either reasonabily deep enough to increase alveolar ventillation, and PO2 arterial will increase, the total amount of oxygen carried by your blood is probably not that much higher, since hemoglobin carries most of the oxygen, and it's pretty much completely saturated at normal physiological conditions anyways. You will get a little more dissolve in blood though, since gas exchange is perfusion limited for most.

Hyperventilation can actually decrease the P02 in your brain also, since a decrease in C02 causes vasoconstriction in brain arterioles. which is why you faint.

Hope that helps!