were do yawns come from???

Question

ive alwaz wondered...

Answer 1

"A yawn is a semi-automatic reflex that originates in the brain stem in response to a lower level of oxygen in the brain. Yawning also occurs when a person loses interest in their surroundings, i.e gets bored. It does not necessarily indicate fatigue, although people do tend to yawn when they're sleepy. A study was done in which heart rate, skin effects, and muscle tension were measured in 30 young adults before, during, and after yawns. They found that yawning did increase their level of arousal for a short time.

Yawning is an action that occurs throughout the animal kingdom (cats in particular seem to yawn a great deal). In the late 1980s several studies were done in rats, and it was found that rats yawned more in the early morning before awakening and also when they were very hungry. Several different brain chemicals seem to be involved in yawning, but the mechanisms are still not understood.

For example, yawning seems to be contagious. Why is that? (Just reading about yawning made me yawn several times!) In your case, I doubt that a lack of oxygen is the main reason you yawn. Since your yawning spells seem to occur mainly around bedtime or during the middle of the night, they probably are related to being sleepy and groggy. "

Answer 2

From watching Paris Hilton's latest "music" video.

Answer 3

Your question made me yawn.

Answer 4

its a signal from your brain that tells your body you need oxygen.

Answer 5

as sunshine said is correct, and i do believe it's a natural way. if we do not yawn, things might become a small problem and later becomign big. i dunno. i maybe stretching.

Answer 6

lack of oxygen in our body.

Answer 7

no one knows where they come from or why we do it.