Monday, August 23, 2010

Why do we yawn?

Let’s start with fundamentals. Normally, when we breathe in, we inhale oxygen and our body uses it up. The body makes a waste product called as carbon dioxide that is exhaled from the lungs when we breathe out.

When we are sleepy, bored or tired, we breathe more slowly. So, our brain makes us take an extra breath, which is deep and long called a yawn, so that you can take in more of oxygen and give out carbon dioxide fully.

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.

One question which I am still pursuing (googling is more appropriate word!) - What's behind this mysterious chain reaction of yawning?

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3 comments:

MeDiOcRe said...

probably the extra CO2 spewed out... gets inhaled by others and thus the chain reaction.. :)..

just a guess though

Abid Mohammed said...

Good guess dude, hope to get the answer somewhere sometime :)

Anonymous said...

i think he is right...