Why do we yawn??

Question

I know we yawn when we're tired, bored or need more oxygen. But WHY yawning?? And how is it so infectious??

Answer 1

Here is the answer-
Hypothesized causes of yawning
An indication of tiredness, stress, over-work, or boredom.
An action indicating psychological decompression after a state of high alert.
A means of expressing powerful emotions like anger, rejection, apathy or tedium.

A cat yawning A previous long-standing hypothesis is that yawning is caused by an excess of carbon dioxide and lack of oxygen in the blood. The brain stem detects this and triggers the yawn reflex. The mouth stretches wide and the lungs inhale deeply, bringing oxygen into the lungs and hence to the bloodstream. It is almost certain, however, that this hypothesis is not correct. One study has documented that this effect does not exist.

A more recent hypothesis is that yawning is used for regulation of body temperature. Another hypothesis is that yawns are caused by the same chemicals (neurotransmitters) in the brain that affect emotions, mood, appetite and other phenomena. These chemicals include serotonin, dopamine, glutamic acid and nitric oxide. As more of these compounds are activated in the brain, the frequency of yawning increases. Conversely, a greater presence in the brain of opiate neurotransmitters such as endorphins reduces the frequency of yawning. Patients taking the serotonin reuptake inhibitor Paxil (Paroxetine HCl) have been observed yawning abnormally often.

Another theory is that yawning is similar to stretching. Yawning, like stretching, increases blood pressure and heart rate while also flexing many muscles and joints. It is also theorized that yawning helps redistribute an oil-like substance which coats the lungs and aids breathing. Some have observed that if you try to stifle or prevent a yawn by clenching your jaws shut, the yawn is unsatisfying. As such, the stretching of jaw and face muscles seems to be necessary for a good yawn.

Another theory is that yawning occurs to stabilize pressure on either side of the ear drums. The deep intake of air can sometimes cause a popping sound that only the yawner can hear; this is the pessure on the inner air stabilizing. This commonly occurs in lower-pressure environments, such as inside an airplane, which cause the eardrums to be bent instead of flat.

Some movements in psychotherapy such as Re-evaluation Counseling or co-counselling believe that yawning, along with laughter and crying, are means of "discharging" painful emotion, and therefore can be encouraged in order to promote physical and emotional healing.

Answer 2

We yawn to get more oxygen to the brain!!! I find that yawns are a 100% contagious. Just thinking about it makes me tired!!

Answer 3

right , your brain lacks oxygen and yawning is just a relfex to replenish the loss. it's not infectious maybe lesser oxygen in the area wld mean everyone yawns

Answer 4

One of my students in the high school where I sub said there has been a recent study that dispels the notion that it is contagious.
I trust this kid, I know him well enough to know he's bright.
and during a long lock-down drill ,I found that I could not get any of the kids to settle down and think they were sleepy by yawning. I hoped it would catch on so they would act tired, not rowdy.
Yeah, right.
No such luck.

Answer 5

Okay, so why did I start yawning my head off as soon as I began to read the word 'yawn'? It's like when you are thirsty and you think of lemons ... try it.

Answer 6

Yawning is infectious they tested it on MythBusters

Answer 7

You because you need more oxygen. Once you have taken a deep breath of oxygen, those around you begin to need more oxygen.

Answer 8

Yawning is to get more Oxygen into the body quickly.

OK then it isn't! Please yourself but that is what causes yawning.

Answer 9

Lack of oxygen

Answer 10

people like you make me yawn