Why do you get hyper/hypo CO2 with hypo-hyperventilation: but O2 is not affected

[str8flexed]

If you hyperventilate, you breathe fast and lose lots of CO2 so you have respiratory alkalosis. Cool. But if you breathe fast don't you lose lots of O2 too? Why is everything talking about CO2 but not the ventilation of O2 with hyperventilation and hypoventilation?

Is it because O2 diffuses faster than CO2 (I don't know; I'm asking you guys), so O2 will diffuse across the alveolar membrane and into the blood regardless of how fast you ventilate?

Edit: Thermosticles answered my question. See the last post.

---

Members don't see this ad.

 

[bakanoisha]

People are probably concerned with CO2 because it plays a significant role in blood pH and O2 doesn't. ^_^

 

[str8flexed]

This might have answered my own question: people hyperventilate to give themselves more oxygen, so I guess even with hyperventilation the O2 is still diffused so rapidly that it is not "blown out" as CO2 is.

Just need some confirmation...

 

[Captopril]

bump. I've always wondered this as well. was always too lazy to look it up, so just took it at face value

 

[McGillGrad]

O2 is fully saturated at normal breathing. It is not affected by deep hyperventilation. But, O2 is affected by shallow hyperventilation, which is the same as hypoventilation.

 

[str8flexed]

O2 is fully saturated at normal breathing. It is not affected by deep hyperventilation. But, O2 is affected by shallow hyperventilation, which is the same as hypoventilation.

Shallow hyperventilation just means that the dead space in your trachea, etc., becomes a larger proportion of your tidal volume, therefore hypoventilation, I suppose. But I'm just trying to figure out the difference between O2 and CO2.

(As a side note, this is why dogs pant really fast and don't hyperventilate--they are simply moving dead space in and out to cool themselves down but aren't exhaling extra CO2 because the dead space air exchange does not reach the alveoli!)

 

[bakanoisha]

What do you mean by "the difference"? I interpreted your question as "why do people discuss CO2 and not O2 when referring to hyper- and hypoventilation?"

 

[str8flexed]

What do you mean by "the difference"? I interpreted your question as "why do people discuss CO2 and not O2 when referring to hyper- and hypoventilation?"

I just mean, why does hyperventilating cause you to lose CO2 but not lose O2. (that would defeat the purpose of hyperventilating to "get more oxygen"). I suspect that it's because O2 diffuses faster.

 

[Knicks]

I just mean, why does hyperventilating cause you to lose CO2 but not lose O2. (that would defeat the purpose of hyperventilating to "get more oxygen"). I suspect that it's because O2 diffuses faster.

I think the purpose of hyperventilating is to get rid of/decrease CO2 and therefore by virtue of doing that, you are, at the same time, "getting more oxygen".

Someone double-check that for me, though.

 

[bakanoisha]

I just mean, why does hyperventilating cause you to lose CO2 but not lose O2. (that would defeat the purpose of hyperventilating to "get more oxygen"). I suspect that it's because O2 diffuses faster.

The oxygen that gets into the blood stream wouldn't have a chance to escape until that same unit of blood has made it through your circulatory system circuit and back to the lungs, right? So, because the oxygen is circulating and trapped within the circuit your body can still utilize it as is necessary, so I don't think you have to worry about losing oxygen because what's making it back to the lungs would be excess, right? As was said earlier, O2 would be saturated... so lost O2 is of no consequence.

I wouldn't take my word as gold... if you wanna know why, just look under my username. LOL. But, I do believe that would be the reason.

 

[str8flexed]

I think the purpose of hyperventilating is to get rid of/decrease CO2 and therefore by virtue of doing that, you are, at the same time, "getting more oxygen".

Someone double-check that for me, though.

That may play some role: by getting rid of CO2, the partial pressures of O2 may be higher, causing faster diffusion. But that still doesn't explain why hyperventilating "gets rid of CO2 causing you to get more oxygen" and why it doesn't "get rid of O2 causing you to get more CO2"

 

[Themistocles]

That may play some role: by getting rid of CO2, the partial pressures of O2 may be higher, causing faster diffusion. But that still doesn't explain why hyperventilating "gets rid of CO2 causing you to get more oxygen" and why it doesn't "get rid of O2 causing you to get more CO2"

It might be helpful for you to think about the normal concentration gradients between the air in the lungs and the blood as it reaches the alveoli (greater CO2 in blood, greater O2 in air). Hyperventilating should just increase the rate at which CO2 is 'cleared' from the lung, lowering the CO2 concentration in the air of the lung, so there will be an accompanying increase in CO2 movement out of the blood. The partial pressure of O2 in the lungs should actually increase, which if anything would increase the drive of O2 into the blood; you wouldn't "get rid of O2" because in either normal breathing or hyperventilation the concentration gradient is going to push O2 into the blood.

 

[str8flexed]

It might be helpful for you to think about the normal concentration gradients between the air in the lungs and the blood as it reaches the alveoli (greater CO2 in blood, greater O2 in air). Hyperventilating should just increase the rate at which CO2 is 'cleared' from the lung, lowering the CO2 concentration in the air of the lung, so there will be an accompanying increase in CO2 movement out of the blood. The partial pressure of O2 in the lungs should actually increase, which if anything would increase the drive of O2 into the blood; you wouldn't "get rid of O2" because in either normal breathing or hyperventilation the concentration gradient is going to push O2 into the blood.

You're totally right. Hyperventilating just increases gas exchange. In this case, CO2 from blood diffuses out into the lungs and is breathed out, while O2 in the air/alveoli diffuses into the pulmonary capillaries. Movement of the two gases, in opposite directions, is both increased. The relatively high O2 concentration in air, and the relatively high CO2 concentration in venous blood cause them to diffuse their relative directions.

Therefore, with hyperventilation, more CO2 is lost but more O2 is gained as well.

 

[McGillGrad]

Therefore, with hyperventilation, more CO2 is lost but more O2 is gained as well.

Like I said before they are not equal because the O2 is at its upper limits 100mmHg and cannot go much higher than (although in questions they may show 103-108mmHg). Since the C02 is continually removed when you breathe out, it keeps dropping.

 

[a winner is you]

Alveolar CO2 is LOWER than venous CO2. Alveolar O2 is HIGHER than venous O2.

 

[turkeyjerky]

Alveolar CO2 is LOWER than venous CO2. Alveolar O2 is HIGHER than venous O2.

LOL @ this thread and the fact that it took so long for someone to point out this simple explanation