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Here is a response I received privately, so I'll leave it anonymous.
Basically, I still don't get how your blood can magically absorb more
oxyhemoglobin than it needs. Any further comments anyone? Thanks.
Cam
> Date: Wed, 19 Sep 2001 07:08:00 -0500 To: "Cam Banks" <cam@ca*.co*>
> Subject: Re: weekly dumb question
>
> In the pulmonary capillary beds, O2 binds to hemoglobin to make oxyhemoglobin.
> More O2 diffuses directly into solution in the bloodstream. Out in the
> peripheries, the cellular life processes take the oxyhemoglobin in, extract
> the O2, and release hemoglobin. The hemoglobin then rebinds with dissolved
> O2, and the process repeats itself.
>
> Observe that there is FAR more oxyhemoglobin circulating than is needed by the
> body from instant to instant, so that when it gets out to the farthest point
> from the capillary beds, even though every cell on the way has extracted its
> cut of the take, there is still plenty of oxyhemoglobin to keep your right
> little piggy happy.
>
> Now, oxygen is a gas, just like nitrogen and helium, and is subject to the gas
> laws and physics, just like nitrogen and helium. It dissolves in the tissues,
> just like them. It is also consumed by the tissues, as needed, unlike them.
> This is just another transport phenomenon. Oxygen diffuses freely across the
> capillary walls in the pulmonary beds, in both directions, just like nitrogen
> and helium. (The miracle of hemoglobin oxygenation depends on free diffusion
> one way. The miracle of deco depends on it going the other way as well.)
> When the excess oxygen returns to the pulmonary capillary beds, if the partial
> pressure of oxygen in the blood is sufficiently higher than the partial
> pressure of oxygen in the airspace, the excess oxygen will diffuse out.
>
> Now, if you have a heavy oxygen load in the slow tissues, caused by e.g. a
> long deco on hot mixes, and you spike the ascent rate sufficiently, just as
> with nitrogen and helium, you can trigger the aggregation of microbubbles into
> macrobubbles, and develop DCS. This is "oxygen bends". The key difference is
> that the cells in the immediate vicinity of the oxygen macrobubble all scream
> "ICE CREAM! We're gonna have ICE CREAM!" and consume the oxygen macrobubble
> in situ.
>
> I remember reading somewhere that oxygen bends has been demonstrated on goats,
> and the goats cleared the symptoms almost immediately, as cellular biology
> eliminated the bubbles.
>
>
> ----- Original Message ----- From: Cam Banks <cam@ca*.co*> To: Techdiver
> Mailing List <techdiver@aquanaut.com> Sent: Tuesday, September 18, 2001
11:50
> PM Subject: weekly dumb question
>
>
>> Okay, time for a weekly dumb one: can someone explain to me the physiological
>> mechanism by which nitrox works?
>>
>> On the face of it, it would seem like once your body had used all the oxygen
>> it needed from a lungful of gas (any mix), the rest of it would diffuse into
>> your blood, regardless of gas type.
>>
>> How is it that we are able to magically dispose of the excess oxygen? What
>> are "oxygen bends" that I've heard alluded to? Thanks.
>>
>> Cam
>>
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