Why do we yawn?

No explanation I have heard makes sense. The more I think about it, the more I get..........

oops

Ideas?

hence, relax=rest=sleep?

why!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

okay. Taking a deep breath now.

Why!!!!!!

If you yawn you need sleep but want to stay up

That's one theory I've heard...

Maybe you should ask why they happen to be so contagious.

maybe.

It causes you to take a deep breath, and the oxygen helps to stimulate the brain, so it is meant to help you wake up.

or else there's a completely different reason. :evilgrin:

or something like that

Just because we're a little tired, or bored?

Why would boredom, but being wide awake, cause the same response?

eom

Yawning expands your lungs in order to take in more oxygen as you inhale automatically. Don't fight yawns. It means you need more O2.

Does it to me every time.....zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

good one!

it has to do with expelling some of the C02 in your bloodstream... notice that most yawns are on exhales, and usuially when they arent, thiers one right after it that is. why its contageous, is something subconcious, your brain says oh, that person is next to me, thier yawning, it must be time for me to yawn too... and thus you yawn.

why it happens after/while your bored or tired, often your not doing alot of physical activity during those times, so CO2 builds up faster than when your active.

thats the most common theory ive heard. but then again, thiers no way to prove if removing CO2 is the cause or a side affect, but alot of it does leave your system.

-LK

The best (not necessarily accurate) theory I've heard is we yawn because our body needs to equalize pressure on our eardrums.

It's "contageous" because once we've equalized our OWN pressure, the air we added/subtracted to the environment causes the folks around us to be out of balance as well, so they have to yawn to compensate.


Hammies!