Why do we yawn? Does anyone know?

Question

I have asked alot of people and no one seems to know but its not just when we are tired apparently

Answer 1

I think it's because our brains need more oxygen, as that must be what happens when we yawn.

Answer 2

Its to simply give our brains oxygen.

Answer 3

Oxygen, apparently when people besides you yawn, you helplessly will too. Don't know if it is 100% true but when someone near you yawns, you react back thinking that they are taking in the surrounding oxygen, so you tend to do it as well to regain more oxygen. Might not make sense but just something i would like to share.  

Answer 4

My theory - yawning is stretching of the diaphragm, and is related to stretching one's body as we do when we have been inactive for a while. Stretching improves elasticity of the muscles and increases their potential. Stretching helps us to stay alert, it tones up our muscles and helps them to be ready for a burst of activity, if needed.

Yawning does exactly that.

Answer 5

Simple you yawn because you need more oxygen. You breath in more air and hence more oxygen. Ever wonder why they are so contagious this is because you see someone yawn your own brain thinks they are yawning so there it most be low in oxygen so therefore I need to Yawn as well.

Hope this helps...Richard

Answer 6

it's not known for definite why people yawn.

when you yawn you get a burst of oxygen, so it probably happens when we feel groggy or bored.

yawning is catching too, if we see someone yawn, we yawn too.

did you know babies yawn in the womb too? it makes no sense for a fetus to yawn as they dont breathe oxygen.

so no-one knows why we yawn.

Answer 7

To give the brain a quick blast of oxygen or when sympathetically induced by someone else yawning.

Answer 8

There are many hypothesis for Yawning????

We expel out Carbon-dioxide when we yawn.... so we yawn when there is more blood carbon-dioxide in our body in ratio with the blood oxygen.

The reasons for excess Co2 may be because of tiredness,stress, overwork, lack of stimulation, or boredom or any other cause

Yawning is a reflex of simultaneous inhalation of air and stretching of the eardrums, followed by exhalation of breath.

http://en.wikipedia.org/wiki/Yawning

Answer 9

a yawn is your bodies way of telling you your brain needs more oxygen.... a yawn is a very deep breathe and takes a lot of oxygen in fast... yawning is contagious though, one person yawns and you have to as well...

funny fact.... dogs do it too! lol xxxx

Answer 10

When your body is feeling tired a yawn gives it a quick sharp burst of oxygen to wake you up a bit - i think!

Answer 11

When you yawn, more oxygen is sent to your brain.

Sorta like...brain air-conditioning!

But scientists aren't exactly sure why we yawn. There are a whole bunch of theories. Some think it's a way to deal with ear pressure or equalize it. Others think it's a way to express nervousness.

There's a whole list of theories on Wikipedia if you have the time to look 'em up.

http://en.wikipedia.org/wiki/Yawning

Answer 12

bored,tired,need more oxygen,poor company,nowt to do,lazy  

Answer 13

people find you boring

Answer 14

In human anatomy we learned that it is to expand the lungs.. sorta like when you sigh..

It is important for the lungs.

Answer 15

Well people usually think that it means your tired. BUT THIS IS WRONG!

The real reason is because your brain isn't getting anough oxygen, so it tell us to yawn, as a way to get more oxygen to the brain.

Answer 16

Those guys are stupid. It has been proven that it is NOT lack of oxygen in scientific studies. See this link: http://www.abc.net.au/science/articles/2...

In truth, no one knows. There are theories, like tribal behaviours left over from mankinds earlier days, but in truth no one can prove one theory beyond reasonable doubt.

There.

Answer 17

Causes of yawning:

The deep inhalation during a yawn is means of preventing alveolar collapse within the lung.

The deep inhalation while yawning stretches type II alveolar pneumocytes, which release the surfactant dipalmitoylphosphatidylcholine (DPPC) into the layer of fluid on the alveolar surface.

A means of cooling the brain.

An action used as an unconscious communication of psychological decompression after a state of high alert.

An excess of carbon dioxide and lack of oxygen in the blood.

A way of displaying (or indicative of) apathy.

Tiredness.

A means of equalizing middle ear pressure, which can be triggered by another's yawning.

Need of food or hunger/ appetite due to reduced level of Glucose supplied to the brain