In sedentary condition or when we are too tired our reflexes tell us to gulp extra bit of air so that we take a little more of oxygen and release a bit more of carbon dioxide formed in the body.
2007-07-25 05:55:04
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answer #1
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answered by Ishan26 7
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Everybody yawns — from unborn babies to the oldest great-grandparent. Animals do it, too. But why, exactly, do people and animals yawn? No one knows for sure. But there are many theories (ideas) about why people yawn.
One is that when we are bored or tired, we just don't breathe as deeply as we usually do. As this theory goes, our bodies take in less oxygen because our breathing has slowed. Therefore, yawning helps us bring more oxygen into the blood and move more carbon dioxide out of the blood.
Yawning, then, would be an involuntary reflex (something we can't really control) to help us control our oxygen and carbon dioxide levels. Sounds good, but other studies have shown that breathing more oxygen does not decrease yawning. Likewise, breathing more carbon dioxide does not increase yawning. Hmmm. Now what?
Another theory is that yawning stretches the lungs and lung tissue. Stretching and yawning may be a way to flex muscles and joints, increase heart rate, and feel more awake.
Other people believe that yawning is a protective reflex to redistribute the oil-like substance called surfactant (say: sur-fak-tunt) that helps keep lungs lubricated inside and keeps them from collapsing. So, if we didn't yawn, according to this theory, taking a deep breath would become harder and harder — and that would not be good!
But there is one idea about yawning that everyone knows to be true. It seems contagious. If you yawn in class, you'll probably notice a few other people will start yawning, too. Even thinking about yawning can get you yawning. How many times have you yawned while reading this article? We hope not many!
2007-07-17 16:47:25
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answer #2
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answered by Mary W 4
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Because yawning is the body's way of inhaling more oxygen and getting rid of more carbon dioxide. When you're yawning or there's people in a room with you who are also yawning it is because you are in an environment without much oxygen. The more you yawn in that case the more you will from use of the oxygen in the room. If you were to open a window in a room with a group of yawning people the "contagious yawning" would stop from fresh oxygen flowing into the room.
2007-07-17 16:27:29
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answer #3
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answered by I want my *old* MTV 6
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THE TRUTH IS that we don’t completely understand why people, or animals for that matter, yawn.
It’s widely assumed that yawning occurs because we are tired or bored or because we see someone else doing it, but there isn’t any hard evidence to support these beliefs.
Scientists do not purport to know all of the biological mechanisms of the yawn, but tend to agree that a yawn is an involuntary respiratory reflex, which regulates the carbon dioxide and oxygen levels in the blood.
Technically, a yawn is the reflex opening of the mouth followed by the deep inhalation and slow exhalation of oxygen.
The very act of yawning is but one of a number of involuntary reflexes controlled by the spinal and nerve centers.
Scientists speculate that the onset of a yawn is triggered either by fatigue, or by sheer boredom as, at those times, breathing is shallow, and little oxygen is carried to the lungs by the oxygen-toting cardiovascular system.
When one yawns, his or her alertness is heightened, as the sudden intake of oxygen increases the heart rate, rids the lungs and the bloodstream of the carbon dioxide buildup, and forces oxygen through blood vessels in the brain, while restoring normal breathing and ventilating the lungs.
This quite plausible theory of yawning falls short of explaining many aspects of yawning. Scientists explain away the "contagious" nature of yawning, that is when one person's yawn triggers another nearby to yawn, as due to the power of suggestion, but are at a loss when attempting to explain why yawning occurs excessively in patients with lower brainstem damage or with multiple sclerosis.
Other unlocked mysteries include why fetuses in the womb yawn, when it is a well-known fact that they do not intake oxygen into their lungs until after live birth, or why individuals with high concentrations of oxygen in their blood streams yawn.
Until these questions are answered, do not assume that a person who yawns in your presence is bored with what you are saying, or suffers from exhaustion. Simply be pleased that he or she is not bored to death.
For more interesting facts check out the websites I listed!
I hope this helps!
2007-07-17 20:31:04
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answer #4
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answered by hot_singing_babe 4
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THE TRUTH IS that we don’t completely understand why people, or animals for that matter, yawn.
It’s widely assumed that yawning occurs because we are tired or bored or because we see someone else doing it, but there isn’t any hard evidence to support these beliefs.
Scientists do not purport to know all of the biological mechanisms of the yawn, but tend to agree that a yawn is an involuntary respiratory reflex, which regulates the carbon dioxide and oxygen levels in the blood.
Technically, a yawn is the reflex opening of the mouth followed by the deep inhalation and slow exhalation of oxygen.
The very act of yawning is but one of a number of involuntary reflexes controlled by the spinal and nerve centers.
Scientists speculate that the onset of a yawn is triggered either by fatigue, or by sheer boredom as, at those times, breathing is shallow, and little oxygen is carried to the lungs by the oxygen-toting cardiovascular system.
When one yawns, his or her alertness is heightened, as the sudden intake of oxygen increases the heart rate, rids the lungs and the bloodstream of the carbon dioxide buildup, and forces oxygen through blood vessels in the brain, while restoring normal breathing and ventilating the lungs.
This quite plausible theory of yawning falls short of explaining many aspects of yawning. Scientists explain away the "contagious" nature of yawning, that is when one person's yawn triggers another nearby to yawn, as due to the power of suggestion, but are at a loss when attempting to explain why yawning occurs excessively in patients with lower brainstem damage or with multiple sclerosis.
Other unlocked mysteries include why fetuses in the womb yawn, when it is a well-known fact that they do not intake oxygen into their lungs until after live birth, or why individuals with high concentrations of oxygen in their blood streams yawn.
Until these questions are answered, do not assume that a person who yawns in your presence is bored with what you are saying, or suffers from exhaustion. Simply be pleased that he or she is not bored to death.
2007-07-21 16:44:07
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answer #5
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answered by Superman 2
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Yawn, comes from there Latin word oscitare, meaning to open the mouth wide. There are different hypothesis out there for yawning, one thats been around for a while suggests that there is excess CO2 in in the blood and not enough O2, so the body detects it and causes yawning, bringing air into the lungs, but recent studies seem to deny this.
Recent studies propose that yawning is associated with regulation of body temperature, another study also proposed that yawning is effected by the chemical/hormones that regulate emotions, and mood, such include serotonin, glutamic acid, nitric oxide.
Other theories include that yawning is sort of like stretching, which in turn increases your heart rate, blood pressure, and redistribution of surfactant in the alveolis in the lungs.
Lastly another theory proposes that yawning helps to stabalize pressure on either side of the ear drums, kinda of like a machine, to balance pressure.
hope it helps
2007-07-17 16:38:05
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answer #6
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answered by playpwnsu 2
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From what i have been told we yawn beause we are bored e.g. if you have to wait at a bus stop with nouthing to entertain you'd notice you yawn more
2007-07-19 10:05:34
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answer #7
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answered by Claiire 6
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we yawn to keep ourselves awake. its a signable from our brain to stay alert otherwise we might fall asleep.
2007-07-17 16:31:25
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answer #8
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answered by jessie 3
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I am not really sure but I think it's through lack of oxygen.
2007-07-25 05:31:07
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answer #9
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answered by Anonymous
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Its a sign that your brain needs oxygen!
2007-07-20 19:34:00
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answer #10
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answered by andrea f 1
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