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Author Topic: Why do we yawn??  (Read 11263 times)

Offline chat250

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Why do we yawn??
« on: 27/06/2003 19:38:09 »
I dont know if i spelt 'yawn' right but what I mean is when you tired and you open you mouth and take a deep breath
« Last Edit: 16/08/2003 13:39:51 by Exodus »


 

Offline Quantumcat

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Re: Why do we yawn??
« Reply #1 on: 28/06/2003 04:23:14 »
It's because you are so tired that you don't breathe enough, the brain is a little deprived of oxygen and makes you take a deep breath to get more oxygen for itself.

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Offline Exodus

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Re: Why do we yawn??
« Reply #2 on: 28/06/2003 11:07:22 »
You can also consider the reciprocal in that you are expelling more CO2.

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Offline Broca

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Re: Why do we yawn??
« Reply #3 on: 29/08/2003 03:01:45 »
I think there are some thoughts that a yawn can be a phisiological response as well. Like, if you are watching someone eat, you become hungry. I know when I see someone yawn, I oft times will yawn as well.
 

Offline Ians Daddy

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Re: Why do we yawn??
« Reply #4 on: 29/08/2003 04:10:41 »
I yawned while reading this. Seriously. Just thinking of a yawn.
 

Offline Quantumcat

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Re: Why do we yawn??
« Reply #5 on: 29/08/2003 04:43:48 »
I think when you yawn when someone else yawns, it's because you see someone else yawn, your brain realises there might not be enough O2 in the air, and makes you yawn too. Corret me if I'm wrong, though :P

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« Last Edit: 29/08/2003 04:44:15 by Quantumcat »
 

Offline bezoar

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Re: Why do we yawn??
« Reply #6 on: 30/08/2003 04:07:36 »
I yawn a lot when I'm too cold.

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Offline cuso4

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Re: Why do we yawn??
« Reply #7 on: 02/09/2003 08:20:33 »
May be it's because your body needs more oxygen for respiration, so you can generate energy to keep warm?

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Offline chris

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Re: Why do we yawn??
« Reply #8 on: 02/09/2003 12:19:26 »
Angel - where have you been, not seen much of you lately !

Chris

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Offline Qing

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Re: Why do we yawn??
« Reply #9 on: 02/09/2003 12:41:22 »
I start yawning when I start reading this topic.:D (only because I see you talking about yawning)
has anyone experienced yawning continuously for a long time and you think you can't stop yawning.[?]

Qing
« Last Edit: 02/09/2003 12:42:35 by Qing »
 

Offline cuso4

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Re: Why do we yawn??
« Reply #10 on: 03/09/2003 19:23:30 »
quote:
Originally posted by chris

Angel - where have you been, not seen much of you lately !

Chris

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I have been around, just didn't post much. Sometimes discussions become too complicated and I don't know what to post. I'm back now that my brain switches on again after a long break.

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Offline mm

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Re: Why do we yawn??
« Reply #11 on: 04/09/2003 17:30:55 »
how does the brain get the information that we need more oxygen? how does the brain 'realise' that we need to yawn too when we see others yawning? I know that our brain is amazing but, can someone actually explain to me 'how'? Cheers~   [?][|)]
 

Offline chris

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Re: Why do we yawn??
« Reply #12 on: 04/09/2003 20:52:11 »
The brain uses detectors in the arteries (aorta and carotid) to provide information about arterial gas tension and pH which it uses to co-ordinate breathing accordingly.

As you become hypoxic (low on oxygen) the brain increases the rate of respiration to compensate. Similarly, if the level of carbon dioxide rises, and the pH falls (due to rising carbon dioxide and / or the presence of lactic acid) the level of respiration rises to 'blow off' more carbon dioxide.

For this reason mountaineers at high altitude hyperventilate (involuntarily) to maintain oxygenation. This drives off carbon dioxide, making the blood alkaline and causing some of the symptoms of altitude sickness.

It also gives rise to a strange breathing phenomenon call Cheyne-Stokes breathing where people breathe rapidly for a short while, then stop breathing for ages, then resume rapid breathing again.

chris

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Offline bezoar

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Re: Why do we yawn??
« Reply #13 on: 04/09/2003 23:22:53 »
Thanks Chris,
I never knew the actual mechanism for altitude sickness.  Why are some people more susceptible than others.  I've never felt particularly affected by altitude in say Denver, Colorado whic is over a mile high, and Mexico city.  But, I've been with fellow travelers who got terribly sick and had to take to the bed.  Any reason for the variables in sensitivity -- other than the obvious, smokers vs non-smokers?

Bezoar
 

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Why do we yawn??
« Reply #14 on: 18/12/2007 03:34:00 »
Thanks Chris,
I never knew the actual mechanism for altitude sickness.  Why are some people more susceptible than others.  I've never felt particularly affected by altitude in say Denver, Colorado whic is over a mile high, and Mexico city.  But, I've been with fellow travelers who got terribly sick and had to take to the bed.  Any reason for the variables in sensitivity -- other than the obvious, smokers vs non-smokers?

Bezoar

I know this is a long dead thread, but since it was referenced from http://www.thenakedscientists.com/forum/index.php?topic=11935.msg145535#msg145535, I thought I would respond anyway.

My understanding is that the variability in response to altitude is down to the number and efficiency of your red blood cells, which alters you efficiency in transporting oxygen.  As you acclimatise to high altitude, the number of red blood cells in your blood stream increases, and so you are better able to tolerate the low oxygen supply (this is also a reason athletes like to train at high altitude, since as their red blood cell count goes up, so does their ability to burn more energy (at any altitude).

 

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Why do we yawn??
« Reply #14 on: 18/12/2007 03:34:00 »

 

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