Everyone will yawn, especially when feeling tired, this seems to be a normal action.
Not only does yawning remind us that we should go to bed, we must be reminded that we should be careful! In some cases, frequent yawning may not be normal.
For example, if you have enough sleep, you can't stop yawning. It may be related to sleep apnea. It may also be a precursor to ischemic stroke. It may also indicate an increase in body temperature. Yawning is so important. So that our ancestors may not be yawning on the dog.
Recent researchers have found that yawning may also indicate the occurrence of migraine.
In a cross-sectional study of patients with long-term migraine headaches, 45.4% of patients reported repeated yawning during migraine attacks, while 11.2% occurred during the migraine aura, 24.2% during headache, and 10% during aura. Period and headache period.
'Many symptoms may be accompanied or preceded by a headache. Migraine's non-headache symptoms, such as yawning, may be overshadowed by other symptoms. Patients may also attribute yawning to lack of sleep or insufficient intake of caffeine.' Dr. Juliana H. VanderPluym of the Austrian Department of Neurology said.
For yawning patients, yawning may be a good omen for disease, but for the general population? Why do we yawn?
In fact, we currently have no evidence to point out the exact purpose of yawning.
Weary, feverish, stress, drugs, social or other psychological factors can cause us to yawn, but each of us is still in a different situation.
I. Several hypotheses about yawning
Help us wake up
There have been such incidents abroad: The jurors were fined 1,000 US dollars in court for yawning in court.
Why is yawning considered a bad thing? Because most of the time yawns increase with boredom, drowsiness and fatigue, which is the waking wake-up hypothesis.
A human yawn lasts for about 6 seconds and may also be accompanied by an increase in stretching or other movements. Because of the increase in sleep pressure, doing 'little movements' can help us resist sleepiness.
The specific muscles of the ear (tympanic tensor muscles) are also activated when yawning. This leads to a reset of the eardrum and the range of motion and sensitivity of the hearing, which increases our ability to observe and monitor the surrounding world.
Saying, Why do yawns shed tears? Because yawning mobilizes facial movements to crush the lacrimal gland.
2. Cooling the brain
When we yawn, we usually involuntarily take a deep breath and take cold air into our mouth to cool the brain's blood, cool the brain, keep the brain healthy and clear. This is the temperature adjustment hypothesis.
The horizontal axis is the temperature and the vertical axis is the number of yawns. Studies have shown that the upper and lower temperatures at 20°C seem to be the optimal temperature for yawning, and the number of yawns when the temperature is too low or too high.
When fever occurs, we often see an increase in the number of yawns, suggesting that body warming and yawning are related, but there is no sufficient evidence that it can lower body temperature.
3. Protection
Almost all vertebrates can observe yawning, and yawning seems to be an ancient reflex activity.
When we are still living in the wild and at the stage of social animals, it is very vulnerable to external attacks, so some of the groups will come out as 'sentinel'.
According to studies on other animals, we found that individuals yawn or perform stretching exercises when they are in a state of lower alertness. This reminds other companions that I am in a bad state and need to rest. You have come for me.
Is there a population that does not yawn? It should be there in the initial stages of human evolution, but the 'sentinel' drowsy group and the group that is in a state of alertness all the time, who are more likely to escape danger are obvious.
Nature's survival law of the fittest left 'yawning' genes.
Second, yawning, related to multiple hormones
Stimulation of specific areas of the hypothalamus containing oxytocin neurons results in rodent yawning. Oxytocin is a hormone associated with social and mental health. Injecting oxytocin into other areas of the brainstem can also cause yawning. .
The frequency of yawning in patients with Parkinson's disease was less than that of other patients, which may be related to low levels of dopamine, and dopamine substitutes increase yawning frequency.
In addition, cortisol, a hormone that increases with pressure, can also prevent yawning after the removal of the adrenal gland (cortisol production site). This suggests that stress may also play a role in causing yawning.
Third, too emotional, easier to yawn
Researchers have scanned the brains of infectious yawning populations and found that the ventromedial prefrontal cortex is activated. This area is related to decision-making, and the damage here is also related to empathy (similar to the loss of heart-to-heart ratio).
This kind of empathy makes yawning seem to be a group activity. When we see people yawning next to it, we will yawn. We even see yawning figures, words, and yawns will cause us to yawn. This is The so-called contagious yawns.
Although it cannot be said that empathetic people are less likely to yawn with contagious diseases, the study found that infectious yawning is also reduced in people with autism spectrum disorders and high psychosis.
We also yawn when others yawn.
The pet also yawns when the owner yawns.
So see now, did you hit a few yawns?
