I know some people say you yawn when
your tired but what's the real reason?
And how come when one person yawns
that makes the person next to them yawn too?
2007-12-04 09:32:17 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Biology
Yawning becomes an involuntary reflex after your blood falls to less than a 95% oxygen concentration within your blood. The act of yawning itself is a way for your body to fill your lungs up for a briefly longer period to allow more blood cells to collect the oxygen in the air.
Yawning in a small room they say is subliminal but the usual fact is with the higher concentration of people in the room chances are the number of people is burining up the oxygen in the room making a higher CO2 concentration in the air and making it more difficult for the body to collect the oxygen it wants from the air.
Also physical acitivy burns up oxygen faster than when you sleep. So when yawning is appearing as a sign that you are tired, this simply means your body is trying to slow itself down in order to increase its oxygen concentration.
2007-12-04 09:44:53 · answer #1 · answered by Darin C 7 · 1⤊ 0⤋
the reason people yawn is because the brain is lacking in oxygen. it happens when you are tired because your body is trying to shut down and you keep going so in order to function properly your brain needs an excess supply of oxygen.. as for the chain reaction that this causes, i cannot answer that. i am sorry.
<3justine
2007-12-04 17:41:10 · answer #2 · answered by Anonymous · 1⤊ 0⤋
I actually heard somewhere that yawning goes back to cavemen days and that was their form of some type of communication when one would yawn at another the other would yawn back and apparently thats why it is now contagious.
2007-12-04 17:39:55 · answer #3 · answered by Anonymous · 0⤊ 1⤋
Because they are tired or their brain is lacking oxygen.
2007-12-04 17:35:37 · answer #4 · answered by Nicki G 2 · 1⤊ 0⤋
when your brain is bored, it runs low on air or blood cells or something like that, so it needs fresh air to refresh it.
2007-12-04 17:36:02 · answer #5 · answered by Anonymous · 1⤊ 0⤋
It because....(yawn)....they are really....(yawn)....
Zzzzzzzzzzzzzzz......
What was the question again?
2007-12-04 17:40:23 · answer #6 · answered by Anonymous · 1⤊ 0⤋
i've heard its to cool your brain
2007-12-04 17:35:48 · answer #7 · answered by blackjanuary 3 · 0⤊ 0⤋
that means its time to go home!!! get back to base camp!!! NOW!!!!
2007-12-04 17:35:35 · answer #8 · answered by BMW 2 · 0⤊ 0⤋
idk
2007-12-04 17:39:29 · answer #9 · answered by Anonymous · 0⤊ 0⤋