What is the purpose of yawning?

[Christopher123]

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.

Great.

Now I'm yawning, lol.

 

[Riverrick]

I think it is to completely inflate your lungs once in a while. When we breathe, we don't actually fill our lungs completely. This is referred to as our Tidal Volume, the amount that we breathe in and out. There is still room for more, which is our Inspiratory Reserve Volume.

When we exercise we use those extra volumes and expand our lungs more fully. But in the normal course of the day, they don't get ventilated. Were they never to get expanded, one can get something called atelectasis which can lead to pneumonia.

So....my theory...is that we yawn to ventilate the underused areas of our lungs and keep them healthy.

 

[Kurn]

Perhaps: Yawning is a communication of the brain to the rest of the body or to the body as a whole. It is a communication of the question: "Are we sleeping, or what?"

I'm a philosopher, not a scientist.

 

[jwest]

you yawn to socialize and bond with others around you...
when one yawns, all follow...

 

[Christopher123]

I don't know, but every time I read this thread, I yawn.

Am I the only one?

I think Rednax is trying to make us all sleepy, lol.

 

[Riverrick]

I'm just amazed that BestSmileys had a Yawning category.

I really get off on that stuff! (I'm easy to please.)

 

[Christopher123]

I'm just amazed that BestSmileys had a Yawning category.

I really get off on that stuff! (I'm easy to please.)

Don't feel bad, I'm a smiley addict

 

[Gay Angel]

Here's an article called "Neuroscience for Kids - Yawning" from this website http://faculty.washington.edu/chudler/yawning.html

Everyone yawns - babies, kids, teenagers, adults. Some birds, reptiles and most mammals also yawn. However, the reason why we yawn is a bit of a mystery. There is also very little research about yawning because for most people yawning is not a problem. Here are a few things that are known about yawns:

1. The average duration of a yawn is about 6 seconds.
2. In humans, the earliest occurrence of a yawn happens at about 11 weeks after conception - that's BEFORE the baby is born!
3. Yawns become contagious to people between the first and second years of life.
4. A part of the brain that plays an important role in yawning is the hypothalamus. Research has shown that some neurotransmitters (for example, dopamine, excitatory amino acids, nitric oxide) and neuropeptides increase yawning if injected into the hypothalamus of animals.

You know that when you are bored, you yawn. Scientists have confirmed this observation by comparing the number of yawns in 17-19 year old students who watched music videos to the number of yawns in students who

watched an uninteresting color test bar pattern.
As you might have expected, people who watched the color test bar pattern yawned more (5.78 yawns in 30 minutes) than those who watched the "MTV-like" video (3.41 yawns in 30 minutes.) The average duration of yawns was also slightly longer in the test bar viewing group. One unexpected finding was that yawns in male students had a longer duration than those in female students.

Many people assume that we yawn because our bodies are trying to get rid of extra carbon dioxide and to take in more oxygen. This may make some sense. According to this theory, when people are bored or tired, they breathe more slowly. As breathing slows down, less oxygen makes it to the lungs. As carbon dioxide builds up in the blood, a message to the brain results in signals back to the lungs saying, "Take a deep breath," and a yawn is produced.
The only problem with the excess carbon dioxide theory is that research shows that it may not be true. In 1987, Dr. Robert Provine and his coworkers set up an experiment to test the theory that high carbon dioxide/low oxygen blood content causes yawning. Air is normally made up of 20.95% oxygen, 79.02% nitrogen), 0.03% carbon dioxide and a few other gases in low concentrations. The researchers gave college students the following gases to breathe for 30 minutes:
Gas #1 = 100% Oxygen
Gas #2 = 3% Carbon dioxide, 21% Oxygen
Gas #3 = 5% Carbon dioxide, 21% Oxygen
Gas #4 = Normal Air
Breathing 100% oxygen (Gas #1) or either carbon dioxide gas (Gas #2 and #3) did cause the students to breathe at a faster rate. However, neither carbon dixoide gas nor 100% oxygen caused the students to yawn more. These gases also did not change the duration of yawns when they occurred.
The researchers also looked for a relationship between breathing and yawning by having people exercise. Exercise, obviously, causes people to breathe faster. However, the number of yawns during exercise was not different from the number of yawns before or after exercise. Therefore, it appears that yawning is not due to CO2/O2 levels in the blood and that yawning and breathing are controlled by different mechanisms.

So, the question remains - why do we yawn? Dr. Provine suggests that perhaps yawning is like stretching. Yawning and stretching increase blood pressure and heart rate and also flex muscles and joints. Evidence that yawning and stretching may be related comes from the observation that if you try to stifle or prevent a yawn by clenching your jaws shut, the yawn is somewhat "unsatisfying." For some reason, the stretching of jaw and face muscles is necessary for a good yawn.
It is possible that yawns are contagious because at one time in evolutionary history, the yawn served to coordinate the social behavior of a group of animals. When one member of the group yawned to signal an event, all the other members of the group also yawned. Yawns may still be contagious these days because of a leftover response (a "vestigial" response) that is not used anymore. None of this has been proven true and yawns are still one of the mysteries of the mind.

 

[Christopher123]

Oh, I'm sorry. I didn't realize it was a common thread topic. For a second, I thought I was actually brilliant for coming up with something original. Oh well...

lol! No!

I meant that since yawning is so contagious that anytime I read this thread ABOUT yawning, it makes me yawn.

I didn't mean your thread was boring, sweets. It's just with some people (like me, I happen to be yawning right now) just thinking about yawning can trigger it.

 

[pancake]

I yawned when I read this, hahaha

 

[Christopher123]

I yawned when I read this, hahaha

Pancake, lol. That's the cutest username I've ever seen.

 

[gmoney]

Oh, I'm sorry. I didn't realize it was a common thread topic. For a second, I thought I was actually brilliant for coming up with something original. Oh well...

My friend! You have nothing to be sorry about! I can't believe this hasn't been discussed before here.

I always heard when you yawn, your body releases some kind of enymes that need to be distributed throughout the body.

In some sense, it's almost like an orgasm, but different. Just not a sexual thing.

I've always wondered how it's contagious, though. I mean, when you see someone else yawn, you invariably do it yourself almost immediately, why is that?

 

[c0n0rm]

I've heard that yawning is a social thing too. You often find in a pride of lions that if one yawns - they all yawn. The same thing is true of humans too, if they consider themselves within a social group. That kind of explains why a lot of people have yawned when reading this thread, but just talk of yawning is enough to make someone want to yawn.

I've heard the usual reasons of it being used for an extra boost in blood oxygen levels, in an attempt to wake up the brain (which at that point is tired, or bored) - but don't underestimate the social aspects of it. Apparently we yawn along with people we like who are yawning

 

[star-warrior]

Prolly every kinda mammal does it. I'm doing it right now. It seems to make my eyes tear up and the moisture helps them feel better.

 

[luminum]

I think it's an involuntary action used to heighten oxygen intake when it's low. The reasonw hy you yawn when you're tired is because your breathing is slowing and reducing oxygen intake. Yawning increases air intake in an attempt to waken the body.

 

[inlovewithanton]

I think it's an involuntary action used to heighten oxygen intake when it's low. The reasonw hy you yawn when you're tired is because your breathing is slowing and reducing oxygen intake. Yawning increases air intake in an attempt to waken the body.

That makes sense. I always figured it was my body telling me to go the fuck to bed. lol.

 

[big_sucker]

Whatever causes it.....it causes me to make this really attractive face!

Mmm...squinty eyes, double chin, flared nostrils, and a view of the back of my throat. What wants my number?

 

[GoodbyeSobriety]

A few years back, a good friend and I were sitting in the mall. We saw some lady yawn, and we BOTH yawned right after. After a few laughs, we came up with a theory:

To this day, I'm a firm believer that yawning is psychologically contagious.

We tested our theory, when someone looked at him or me, we would fake a long-yawn. We tried this several times, and more than half the time the person yawned seconds later.

My second guess- yawning stretches muscles in our mouth and throat. I yawn the most when I am not talking.

Both theories are my opinion.

 

[JASON0980]

Argh! Started reading this thread and ive had like 5 or 6 yawns in the space of 5 mins!!!

everytime i see it in the thread list i yawn!

well it might have some thing to do with the fact that its 5:30 am here......

 

[trawler69]

I hadn't yawned once today until I read this thread. It isn't boring it is interesting. I tried to fake a couple of yawns and then a real one came on and now I have done several real ones and am beginning to feel tired. Isn't the human brain strange?