Oxygen Metabolism

[cnidae]

When excess Oxygen is dissolved and carried to the tissues by plasma, is all of the oxygen metabolized by the tissues or is only the amount needed metabolized or is it stored in the tissue for later metabolism?

 

[rmediver2002]

The rate of consumption or metabolism at a cellular level does not appreciably increase while under pressure.

The O2 remains in solution in the tissues of the body because of the pressure involved, but is not stored for future consumption. (like stored energy / fat cells)

Jeff Lane

 

[cnidae]

rmediver2002 once bubbled...
The rate of consumption or metabolism at a cellular level does not appreciably increase while under pressure.

The O2 remains in solution in the tissues of the body because of the pressure involved, but is not stored for future consumption. (like stored energy / fat cells)

Jeff Lane

I asked this question because I'm trying to fully understand the oxygen window. So how is the void created in the plasma with decreased ambient pressure and higher partial pressures of 02? Seems that the tissue would be giving up O2 to the plasma when pressure is decreased. Is it because the slow decrease in pressure gives the body enough time to metabolize the O2 so that the tissue is now trying to pull 02 from the plasma? From what I'm getting is it is really time dependent. If you instantaneously changed to the depth you would breath pure 02 it seems you would have a smaller oxygen window. Am I correct?

Thanks

Thanks

 

[rmediver2002]

I asked this question because I'm trying to fully understand the oxygen window. So how is the void created in the plasma with decreased ambient pressure and higher partial pressures of 02? Seems that the tissue would be giving up O2 to the plasma when pressure is decreased. Is it because the slow decrease in pressure gives the body enough time to metabolize the O2 so that the tissue is now trying to pull 02 from the plasma? From what I'm getting is it is really time dependent. If you instantaneously changed to the depth you would breath pure 02 it seems you would have a smaller oxygen window. Am I correct?

Yes you are correct.

The "O2 window" would temporily be smaller, but as you mention it is time dependant, the process becoming more efficient as the amount of O2 in solution within the tissues equalizes with the partial pressure at the depth of the stop.

 

[ColdH2Odvr]

I’ve had the same question in mind and, after reading this thread, finally did a little research. I’ve found a paper that seems to answer your question. Here’s the link: http://www.yeapa.com/docs/deco/brian_oxygen_window.pdf

In a nut shell, we know that oxygen combines with hemoglobin; we also know that the excess oxygen dissolves in the blood like any other gas. What’s not intuitive is that the combination of the two mechanisms has a non-linear effect. The result is that, even though the body metabolizes the same amount of oxygen, the change in PO2 is significantly greater at elevated PO2’s aka a wider oxygen window.

Hope this helps,

Dave

 

[cnidae]

The link doesn't work for me

 

[Dr Deco]

Hello cnidae:

Oxygen Window

I noticed that you asked concerning the oxygen window and mention the plasma. The major utilization of oxygen occurs in the tissues and not in the plasma. Certainly the capillary blood will drain into the venous system and the oxygen deficit will be present, but, in general, little of interest with respect to decompression occurs in the venous system.

Just how much of an oxygen deficit will occur depends on the metabolic rate of the tissue. In the case of nervous tissue, the oxygen utilization is very high and virtually all of the oxygen is removed. The removal is less for kidneys and even less for connective tissue.

Tissues will not give oxygen to the capillaries since the pressure change is virtually always less than the oxygen utilization rate.

Dr Deco :doctor: