Yawns, What Are They?

We all yawn, that’s common knowledge. But what is not common knowledge is the question of why we yawn.

There is recent research that yawning is cooling down the brain. A professor in Princeton and another in the University of Maryland School of Dentistry in Baltimore have made a theory that yawning causes your sinuses to expand and contract like bellows, pumping air into the brain. This action causes the brain to lower its’ temperature. The article says that the brain is similar to a computer because both are heat sensitive. http://news.nationalgeographic.com/news/2011/11/111115-yawning-mystery-brains-sinuses-health-science/

Another theory is that when we are bored or tired, we don’t breathe in deep enough. By yawning, it brings more oxygen into the blood and more carbon dioxide out. Therefore, yawning is an involuntary reflex. But this theory can be disproven by breathing deeply and still yawning.

An additional theory is that yawning is stretching the lungs and lung tissues. This theory also says that stretching and yawning might be a way to flex muscle joints, increasing the heart rate, making you less tired.

Others say that yawning is a reflex to redistribute the oil-like substance called surfactant that helps the lungs from collapsing. Therefore, according to this theory, if we stopped yawning, breathing would be increasingly difficult, until you ceased breathing all together. http://kidshealth.org/kid/talk/qa/yawn.html

It’s also not entirely good to be yawning a lot, even if you are tired. Excessive yawns can cause drowsiness, sleeping during the day, and even heart attacks. http://www.nlm.nih.gov/medlineplus/ency/article/003096.htm

So to conclude, yawning isn’t exactly a known topic in the science field. We can go to the moon and back and know how to create a device that can kill millions, but can’t figure out this little mystery.

What do you think causes yawning? Comment and tell me!