Oxygen..

[TheRealJoeFish]

To be clear, I was being facetious...

[Aractus]

I asked a similar question about blood and the circulatory system the other day and got a very fulfilling answer, so trying again.


So I imagine at an atomic level, or possibly cellular level, things like osmosis or the movement of cells and atoms from one place to another is quite slow? I imagine H2O molecules taking minutes to 'seep' through some membrane?

But my question is to do with the movement of oxygen from the air we breathe to the blood that transports it around our bodies...

If you think about it, you breathe in, and then usually breathe all that air out again straight away ! And only a portion of that air will be against a wall of any sort... how does the transition of oxygen happen quickly and efficiently enough in order to feed how whole bodies?

Diffusion is very very quick, it has to be because blood is continually flowing through the capillaries. O2 is picked up by haemoglobin in the RBCs and transported to cells around the body. Oh and the capillaries around the alveoli are so thin that RBCs only just fit through and thus brush against the membrane maximising diffusion to (CO2) and from (O2) the alveoli.

[zebo-the-fat]

Also, if the air you breath has no oxygen content, your body would not alert you to the fact that you are suffocating. You just pass out peacefully and die.

This is true

I've always wondered why executions were not done with a CPAP mask and a bottle of helium that can be purchased at a party store.

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All birds, dinosaurs and their relatives do it better, even more distant relations of birds like alligators do it better. Most mammals do it poorly.

Another trivia, the gas exchange in a chicken happens inside its bones, abdominal cavity, as well as in its lungs. If you nick the main wing bone of a chicken, you can tape up the chicken's nose and beak, and it can still breath.

How many chickens did you have to nick to figure this out Chuck?

Helium is an expensive way to execute someone, why not use nitrogen, much cheaper. I saw a film where they had volunteers in a chamber with oxygen masks on, some had the oxygen reduced and replaced with nitrogen... they didn't notice, just went to sleep. A low cost and painless way to kill someone if that's what you really need to do.

[Anomalocaris]

This is true

I've always wondered why executions were not done with a CPAP mask and a bottle of helium that can be purchased at a party store.

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How many chickens did you have to nick to figure this out Chuck?

Helium is an expensive way to execute someone, why not use nitrogen, much cheaper. I saw a film where they had volunteers in a chamber with oxygen masks on, some had the oxygen reduced and replaced with nitrogen... they didn't notice, just went to sleep. A low cost and painless way to kill someone if that's what you really need to do.

Helium gas must be extracted as a mining and drilling byproduct. Available mines that produced helium in useful quantities have mostly been exhausted. There are a lot of practical uses for helium and a very finite total inventoy without realistic prospect of serious replenishment in the near future. What is available shouldn't be wasted.

[pocaracas]

Helium is an expensive way to execute someone, why not use nitrogen, much cheaper. I saw a film where they had volunteers in a chamber with oxygen masks on, some had the oxygen reduced and replaced with nitrogen... they didn't notice, just went to sleep. A low cost and painless way to kill someone if that's what you really need to do.

Helium gas must be extracted as a mining and drilling byproduct. Available mines that produced helium in useful quantities have mostly been exhausted. There are a lot of practical uses for helium and a very finite total inventoy without realistic prospect of serious replenishment in the near future. What is available shouldn't be wasted.

I hear that a significant amount of the world's stick of helium is going to be used to cool ITER's superconducting coils... but it's ok, ITER will generate helium as a byproduct of fusion.