Why dont you breath less at depth?

[dhampton82]

I know (to some) that this may seem like a stupid question, but why dont you breath less air or the same amount of air at depth?

I know that the air that you breath in is compressed. But why, since you are breathing in more oxygen with each breath, why wouldn't your body just use that oxygen and just make you need to breath fewer times? Can anyone explain to me the physics or gas laws or what ever that causes this?

I know this may be a stupid question, but my dad asked me about it the other day, and it has been on my mind ever since......

Thanks
Dustin

 

[H2OU]

I think the need to breathe has more to do with getting the CO2 out of the blood and lungs than it does absorbing oxygen. Just a guess though.

 

[TNdiver6387]

Alot of your body's trigger to breathe is elevated CO2 levels. It takes a LOT of training to "reprogram" your body to overcome that urge to breath created by elevated CO2 levels (a major part of freediving). High CO2 levels can also be dangerous. So, the reason you cant breathe less, is really more an issue getting rid of CO2, and the fact that there is more oxygen available doesnt really play into it. Actually, we just about never use all the oxygen in a breathe of air regardless of the situation. The only time we come close is if we hold our breath to the point of blacking out, and then i would assume there would still be a very small amount of oxygen present anyway.

 

[Green_Manelishi]

I know (to some) that this may seem like a stupid question, but why dont you breath less air or the same amount of air at depth?

I know that the air that you breath in is compressed. But why, since you are breathing in more oxygen with each breath, why wouldn't your body just use that oxygen and just make you need to breath fewer times? Can anyone explain to me the physics or gas laws or what ever that causes this?

I know this may be a stupid question, but my dad asked me about it the other day, and it has been on my mind ever since......

Thanks
Dustin

Because the gas is compressed and is more dense but your lungs remain the same and it's necessary to "fill" them when you breathe. The gas law is Boyle's (volume). Wouldn't it be grand though to not have pesky physics in the way. We'd never get bent either !!!

 

[dhampton82]

I think the need to breathe has more to do with getting the CO2 out of the blood and lungs than it does absorbing oxygen. Just a guess though.

This was my initial speculation, I have heard before that the urge to breath was caused by having to much co2 in the body and not by the body needing oxygen.

 

[ScottB]

And at higher levels of Oxygen, Carbon Dioxide becomes more dangerous.. =) but you shouldn't have to worry about in recreational diving..

 

[Charlie59]

Your body generates CO2 as a by-product of cellular metabolism. The rate of CO2 production is the same or higher while diving (more activity means more CO2). The way this is removed is by moving volumes of gas (breaths) in and out of the lungs to clear the CO2. Each breath has a volume. Since the air you breath from your tank must be compressed because of the ambient pressure at depth, it uses more of that air with each breath. The higher oxygen concentration thing is just a bonus.

 

[wedivebc]

And at higher levels of Oxygen, Carbon Dioxide becomes more dangerous.. =) but you shouldn't have to worry about in recreational diving..

Please explain?

 

[H2Andy]

I have heard before that the urge to breath was caused by having to much co2 in the body and not by the body needing oxygen.

this is correct

Please explain?

when you are breathing O2 rich mixes (mostly on deco) after dives in which you've maxed out your O2 load, any buildup of CO2 could trigger an ox tox hit

also, on ascent, CO2 build up (usually due to exertion) starts to be released, and your body will respond with a higher breathing rate, stress (could lead to panic) and sometimes a nasty headache.

 

[wedivebc]

this is correct




when you are breathing O2 rich mixes (mostly on deco) after dives in which you've maxed out your O2 load, any buildup of CO2 could trigger an ox tox hit

Are there studies that prove this? Do you have a link I would like to do some reading.