Yawning Saves Your Brain From Overheating
When you see the other person yawning in the room, your instinctive response is to yawn too. However, it doesn't mean you are fighting with the urge to sleep. Scientists discovered that yawning is a process that protects our brain from overheating and serves as an alert signal to others.
Andrew C. Gallup and Gordon G. Gallup, Jr., researchers from University at Albany studied yawning in college students to find out the reason of yawning. They disproved the theory that yawning results from the lack of oxygen. As experiments showed, the alterations in oxygen and carbon dioxide levels in the blood didn't affect the yawning reaction.
In fact, yawning was found to serve as a brain-cooling mechanism. In the course of the day, our brain heats up as it burns as much as third of all the calories we consume. In order to function more efficiently, the brain needs to be cooled down. Thus when a person yawns he or she instinctively increases blood flow bringing cool air.
During the experiment, students were watching video tapes showing people yawning. Half of the volunteers were asked to breathe through their mouth and the other half was asked to breathe through their nose. As a result, those who were breathing thought their nose didn't yawn, while the rest had an urge to react with yawning.
They also performed another experiment, where students were given a cold pack to hold to their forehead. None of them yawned unlike those who held warm pack.
Experiments showed that brain cools down through nose breathing as it delivers cool blood to the brain. Additional cooling of the head brings in the same effect that's why people do not feel the need to yawn.
Contrary to popular belief, yawning doesn't imply that a person wants to sleep - it may only eliminate the urge to sleep. Researchers also explained the phenomenon of the "contagious yawning" saying that we tend to yawn looking at other person yawning because it draws our attention and this helps the group to stay aware of signs of danger.
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Comments:
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//7 Oct 02, 2009 06:15 PM | posted by:
daddy - This is not false. Air does warm up as it flows through the nose, but that is because it draws the heat from the surrounding tissue. That's how nose breathing cools the brain and blood. In fact, air breathed through the nose passes right by the 'brain temperature tunnel' which is a small area, about where your eyeglasses rest on your nose. This is about the only area available to very efficiently affect the temperature of the brain without ice packs or devices. All other areas have substantial levels of fat and bone covering the blood supply. Blood does not have one temperature throughout the body, instead it draws up heat, which it then carries to natural radiant radiators like the palms and bottoms of the feet.
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//6 Feb 01, 2009 12:54 PM | posted by: Diggidy Dogg - Yeah dude.....
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//5 Dec 25, 2008 07:44 PM | posted by: Danielle - yes i belive it so thank you i am doing this for a scienc fair project and you just helped me alot
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//4 Dec 15, 2008 11:10 PM | posted by: Kantoran - I don't believe this. It doesn't make sense.
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//3 May 22, 2008 01:22 PM | posted by: vendepatria - This is totally false, simply by knowing that when you breathe through your nose the air warms up. Another thing to consider is that the temperature of the blood doesn't change because of the air you breathe. It's always at 36 єC.
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//2 Mar 19, 2008 06:34 AM | posted by: pearl - i once heard that we yawn because our brian needs more oxygen
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//1 Feb 06, 2008 02:31 PM | posted by: Tim - I have always wondered about this! I have observed turtles, snakes and other relatively distant relatives of humans yawning, I knew there must be some important reason behind it! Amazing!
