Why do we yawn?

Question

whats the point of it? Why shoud tiredness make you stretched your mouth? Is it some sort of survival mecahnism.

???

man ive just read through half the answers (really big repsonse thanks people) and boy did I yawn through reading them! lol, goodnight!

Answer 1

When your body needs oxygen

Answer 2

I ready all the answers and i don't agree with the whole Oxygen trend. I think it has more to do with the nerve bundle behind the nasal cavity that works with the eyes, ears, and nose. I believe that pressure builds up in that junction caused by the optic nerve and it effects both the ears and the sinuses creating sympathetic pressure that results a muscular reaction by the muscles of the cins and neck to yawn creating a vibration to off set that pressure. The Oxygen is a benefit but not a triggering mechanism. I think people tend to jump to conclusions because both the brain and the nervous system are so closely related that every thing the nervous system does is brain induced. That is not true. The signals flow in two dirctions to and from the nerves, two and from the brain. What you need to do is relax and focus on the physiological happenings during a yawn and it all makes more sense. The pressure builds up moving from eyes to ears to nose and as I does the ears trigger the jaw and the nose triggers the throat and the vibration of the inhalation pops the ears and and the sinuses restoring things to the way they were or close there to. As for what causes the pressure to the nerve bundle it is my thought that it is cumulative from the eyes, ears, and nose. You forget to breath, you strain to hold your eyes open, pressure builds up in your ears and it all relates to that one bundle. Also, when you hear a yawn the sympathetic vibrations from one yawn trigger the same response in you. Think about it. It all makes sense.The second person does not need Oxygen. The person is just influenced by the vibration and the nerves respond to replicate the event. And I don't think it is a survival mechanism but rather adaptation to the circumstances one encounters. After all, babies yawn, so; it is not learned; it is innate. In the broadest terms it could be seen as survival, but; that is assuming that if you never yawned you would die and that is simply not the case.

Answer 3

A yawn is a reflex of deep inhalation and exhalation associated with being tired, with a need to sleep, or from boredom
A long-standing hypothesis is that yawning is caused by an excess of carbon dioxide and lack of oxygen in the blood. The brain stem detects this and triggers the yawn reflex. The mouth stretches wide and the lungs inhale deeply, bringing oxygen into the lungs and hence to the bloodstream. It is almost certain however, that this hypothesis is not correct. One study documented that this effect does not exist ("Yawning" by Robert R. Provine, pages 532-539, American Scientist, November-December 2005, Vol 93, No. 6). [1]. A more recent hypothesis is that yawning is used for regulation of body temperature. Another hypothesis is that yawns are caused by the same chemicals (neurotransmitters) in the brain that affect emotions, mood, appetite and other phenomena. These chemicals include serotonin, dopamine, glutamic acid and nitric oxide. As more of these compounds are activated in the brain, the frequency of yawning increases. Conversely, a greater presence in the brain of opiate neurotransmitters such as endorphins, reduces the frequency of yawning. Patients taking the serotonin reuptake inhibitor Paxil (Paroxetine HCl) have been observed yawning abnormally often.
Another theory is that yawning is similar to stretching. Yawning, like stretching, increases blood pressure and heart rate while also flexing many muscles and joints. It is also theorized that yawning help redistributes an oil-like substance which coats the lungs and aids breathing. Some have observed that if you try to stifle or prevent a yawn by clenching your jaws shut, the yawn is unsatisfying. As such, the stretching of jaw and face muscles seems to be necessary for a good yawn.

Answer 4

Yes we yawn to get oxygen,
because we are usually breathing
in such a shallow manner that
our body needs a real breath.

BUT!! WHY is yawning
contagious???
I have always wondered that!
I could probably get $ 2 or $ 3
million from the government
to study that, but I am just
too busy with ANSWERS
right now to mess with it.

I have a friend who is a nurse,
and she said that after surgery
they have to make the patient
take a deep breath. Since that
causes the patient so much pain,
they usually resist, so she would
just stand in front of them, and
fake a yawn. The patient would
not be able to resist and would
yawn; thus the deep breath...

Answer 5

A yawn is a reflex of deep inhalation and exhalation associated with being tired, with a need to sleep, or from lack of stimulation. Pandiculation is the term for the act of stretching and yawning. Yawning is a powerful non-verbal message with several possible meanings, depending on the circumstances. It is also claimed to help increase the state of alertness of a person. The exact causes of yawning are still unknown.

The usual cause of Yawning are:

An indication of tiredness, stress, over-work, or boredom.

An action indicating psychological decompression after a state of high alert.

A means of expressing powerful emotions like anger, rejection, apathy, or tedium.

Answer 6

Yawning has several reasons why?

It is a reflex of deep inhalation and exhalation associated with being tired and the need to sleep, or the lack of stimulation. The brain stimulates the body for this reaction to create a hightened state of awareness and alterness in a person. It is a reflex we cannot help. Our body will just do it. The brain senses a state of unawareness and tries to pull us out of it. The brain tries to make us more alert.

The exact reasons though are still unknown. Increasing oxygen supply is unknown. More urban legend than anything. See wikipedia.com. Search for yawning.

Answer 7

What's behind this mysterious epidemic of yawning? First, let's look at what a yawn is. Yawning is an involuntary action that causes us to open our mouths wide and breathe in deeply. We know it's involuntary because we do it even before we are born. Research shows that 11-week-old fetuses yawn.

There are many parts of the body that are in action when you yawn. First, your mouth opens and jaw drops, allowing as much air to be taken in as possible. When you inhale, the air taken in is filling your lungs. Your abdominal muscles flex and your diaphragm is pushed down. The air you breath in expands the lungs to capacity and then some of the air is blown back out.

While the dictionary tells us that yawning is caused by being fatigued, drowsy or bored, scientists are discovering that there is more to yawning than what most people think. Not much is known about why we yawn or if it serves any useful function, and very little research has been done on the subject. However, there are several theories about why we yawn. Here are the three most common theories:


The Physiological Theory -- Our bodies induce yawning to drawn in more oxygen or remove a build-up of carbon dioxide. This theory helps explain why we yawn in groups. Larger groups produce more carbon dioxide, which means our bodies would act to draw in more oxygen and get rid of the excess carbon dioxide. However, if our bodies make us yawn to drawn in needed oxygen, wouldn't we yawn during exercise? Robert Provine, a psychologist at the University of Maryland, Baltimore County, and a leading expert on yawning, has tested this theory. Giving people additional oxygen didn't decrease yawning and decreasing the amount of carbon dioxide in a subject's environment also didn't prevent yawning.
The Evolution Theory -- Some think that yawning is something that began with our ancestors, who used yawning to show their teeth and intimidate others. An offshoot of this theory is the idea that yawning developed from early man as a signal for us to change activities.
The Boredom Theory -- In the dictionary, yawning is said to be caused by boredom, fatigue or drowsiness. Although we do tend to yawn when bored or tired, this theory doesn't explain why Olympic athletes yawn right before they compete in their event. It's doubtful that they are bored with the world watching them.
The simple truth is that even though humans have been yawning for possibly as long as they have existed, we have no clue as to why we do it. Maybe it serves some healthful purpose. It does cause us to draw in more air and our hearts to race faster than normal, but so does exercise. There's still much we don't understand about our own brains, so maybe yawning is triggered by some area of the brain we have yet to discover. We do know that yawning is not limited to man. Cats, dogs, even fish yawn, which leads us back to the idea that yawning is some form of communication.

Answer 8

That's a good question, and it is still highly debated in the medical, biological, and sociological fields.

It is not necessarily out of boredom or lack of oxygen. For example, the next time you are at a high-pressure event (before you play at a ball game, for example) you will find a "need" to yawn. Good example is (just one) right before a basketball game they show the players, and a few of them are caught yawning. Don't know why this is, but it just is.

Lots of people can speculate, and even write about it online. The fact is, there is no direct link between behavioral or physiological signs and yawning.

Answer 9

A yawn (synonyms chasma, oscitation from the Latin verb oscitare, to open the mouth wide[1]) is a reflex of deep inhalation and exhalation associated with being tired, with a need to sleep, or from lack of stimulation. Pandiculation is the term for the act of stretching and yawning. Yawning is a powerful non-verbal message with several possible meanings, depending on the circumstances. It is also claimed to help increase the state of alertness of a person. The exact causes of yawning are still unknown.

Answer 10

When we sleep, we have an auto breather mechanism. Until that mechanism kicks in, its up to our subconscious mind to remember. When we get tired, we kinda forget & don't breath quite as deeply. When this happens, our brain detects a lack of oxygen & therefore sends a transmitter to our bodies communicating a message to take a deep breath. Our brain sayes "look body, we're not getting enough oxygen mmmkay?" Then the body follows suit, giving us an inclination to yawn.
In the case of making sombody yawn, I have heard it said that we do this when someone we like yawns. But that's just "hear say" As to why: I have an idea, it could be related to sympathy.

Answer 11

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.