2007-01-29 06:27:36 · 6 answers · asked by Chris M 1 in Health ➔ Other - Health
To compensate for sloppy breathing due to being tired
2007-01-29 06:31:26 · answer #1 · answered by Invader Zim 5 · 0⤊ 0⤋
The most plausible explanation, and the one that is taught in medical school, is that we yawn because oxygen levels in our lungs are low. Studies have shown that during normal, at-rest breathing, we don’t use anywhere near our lung capacity; for the most part, we just use the air sacs at the bottom of the lungs. If the air sacs, called alveoli, don’t get fresh air, they partially collapse and the lungs stiffen a bit. As a result, it’s believed, our brain prompts the body to either sigh or take a yawn to get more air into the lungs.
Check out the websites below for more interesting info. The first one is where I got the info above.
2007-01-29 14:34:59 · answer #2 · answered by momma mia 4 · 1⤊ 0⤋
When our brains are registering a drop in the level of oxygen, our body responds by yawning and intaking a greater supply of air and therefore of oxygen. We therefore start to feel more alert.
2007-01-29 14:38:23 · answer #3 · answered by The exclamation mark 6 · 0⤊ 0⤋
I think its to get more oxygen into the body, which happens when we're tired, or possibly nervous and anxious.
I yawn a lot when I'm nervous! :)
2007-01-29 14:32:50 · answer #4 · answered by siobhan 4 · 0⤊ 0⤋
It's your body demanding more oxygen.
2007-01-29 14:32:03 · answer #5 · answered by Anonymous · 0⤊ 0⤋
being tired and lack of oxygen
2007-01-29 14:35:00 · answer #6 · answered by shorty 6 · 0⤊ 0⤋