People say that we yawn because were tired, not true because are eyes become heavy when were tired and i yawn sometimes throughout the day even if im not tired. it's like why do we get sweat hands when were scared?
2007-07-18 07:51:09 · 22 answers · asked by Anonymous in Science & Mathematics ➔ Weather
I don't know the answer to this one but...
Last year my dad had a laryngectomy, that is he had his voice box removed and now breaths only through a hole in his neck, yet he still yawns. I find this strange as he has no oxygen intake through his mouth.
2007-07-18 08:03:35 · answer #1 · answered by Hendo 5 · 0⤊ 0⤋
Just before you yawn, most of the Alveoli aren't getting enough air for the gas-exchange to take place. The result: You are getting lesser and lesser oxygen. This happens time to time because the mucus layer(which is present on the inner-walls) completely blocks the entry of air to some of the remote parts of lungs. To clear the Mucus layer, we Yawn.
There are other reasons too, Like, if we are nervous, we take a deep breath. This is similar to yawning.
When we yawn, suddenly large amounts of oxygen becomes available. As a result, your brain fires up for a moment, and you feel comparitively more attentive.
Try this: just when you are about to yawn, shut your mouth, and take a deep breath through your nostrils. This will make you more vigilant for a short time. Then surprisingly, we feel an overwhelming need to yawn again. You wouldn't be able to stop this yawn(and we yawn bigger too!) and now you feel sleepy.
Reason:First time, you breathed in deeply, and your brain flared up. But it used the oxygen soon enough, and there is a shortage of oxygen now. Since you didn't open your mouth, the mucus hasn't been cleared (some mucus clears only if you yawn like a crocodile!). So, the body issues another signal to yawn. and this time, it is strong. Now, when you yawn, the oxygen is all used by body cells, and your brain receives little less oxygen (not life-threatening!).. thus making you feel sleepy.
Hope this helped. Happy yawning!
2007-07-18 08:10:59 · answer #2 · answered by MDA 4 · 0⤊ 1⤋
Firstly, you will sweat when you are scared because usually you will heat up when you are scared, this causes the body to release a hormone into your bloodstream which affects your kidneys this once in the kidnets causes your body to produce sweat to cool you down when it evaporates off your skin thus cooling you and why you might sweat if you are scared (basically if you get hot when you are scared that is why)!
About the yawning though that is because of the extra pressure in your lungs causing you to yawn uncontrollably even if your not tired because increased pressure in your lungs wants to be released so to decrease the pressure you breathe out excessivly causing what we know to be a yawn, you will generally find you will breathe in slightly more than normal before and after a yawn which is when the body is trying to stabalise the pressure in your lungs!
Hope this helps ( sorry about the confusing explanation!)
2007-07-18 08:06:31 · answer #3 · answered by twitbond 1 · 1⤊ 0⤋
We yawn because our bodies aren't getting enough oxygen and a yawn is a quick intake of air that the body needs.
You'll find that when you are concentrating on something, you will yawn quite often. Also, this will happen when you are reading, because reading relaxes you and therefore your breathing because shallower, which is why people say that reading will send you to sleep.
We yawn when we are tired because our breathing gets shallower when our bodies need sleep.
So, basically we don't yawn because we are tired, we yawn because our bodies need a quick shot of Oxygen.
Great question! x
2007-07-18 10:01:49 · answer #4 · answered by Kirk_84 4 · 0⤊ 0⤋
A Yawn tells us that the Body wants to shut down
2007-07-21 06:45:38 · answer #5 · answered by Bludnut 3 · 0⤊ 0⤋
A yawn gives extra oxygen to the brain when you are tired.
2007-07-18 08:04:01 · answer #6 · answered by hardworkingmom 1 · 0⤊ 0⤋
Its to get all of the carbon dioxide out of your body and if u give yourself a face massage in the morning it will make you yawn and you will feel much fresher
2007-07-18 23:26:02 · answer #7 · answered by Superman 2 · 0⤊ 0⤋
A yawn in the weather is a quiet spell eg; lull
2007-07-18 08:01:23 · answer #8 · answered by Anonymous · 0⤊ 0⤋
my science teacher made anyone who yawned stick their head out of the window (even in the winter) because he said it was lack of oxygen that caused you to yawn xxx
2007-07-18 08:12:01 · answer #9 · answered by Anonymous · 0⤊ 0⤋
it is to get a extra intake of oxygen into your system, that's it no mumbo jumbo, why do other people give answers that are so boring they make you sleepy, thus making you bored, therefore you lack oxygen and have to yawn, to stay awake
2007-07-18 10:20:53 · answer #10 · answered by trevor s 3 · 0⤊ 0⤋