Yawning. I’m getting sleepy just thinking about it! But by now, most of you have probably heard that yawns aren’t actually caused by being tired. Or are they?
Yawning, according to one site, is a “…stereotypical reflex characterized by a single deep inhalation (with the mouth open) and stretching of muscles of the jaw and trunk.” Many animals can yawn, as well as humans, and, while the actual process and connection of yawning has never been solved, it has something to do with the brain’s ability to recognize unconscious signals.
People used to believe it was to bring more air when you had little oxygen, but the lungs cannot actually sense the amount of oxygen. In addition, fetuses can yawn, even when their lungs are not ventilated and different parts of the brain control breathing and yawning. People also believe it is when we are bored or tired, but I would be yawning a lot more in some of my classes! 😉 PVN, or paraventricular nucleus, of the hypothalamaus of the brain can cause yawning when there are low oxygen levels, although this is considered unlikely according to one source, as PVN also plays a role in erections, which are not usually from boredom! However, the PVN does contain many chemical messengers like dopamine, glycine, oxycotin, and ACTH, or adrenocorticotropic hormone, which are all yawn-creating agents.
The most recent idea of why we yawn is to cool down the brain, as people reportedly awn more in the winter when the air around them is cold, as opposed to the summer. Yawning is actually contagious, a phenomenon based on the idea that human reactions as a whole are contagious, or have an urge to be copied. Think of monkey see monkey do, or, more relate-able, someone’s infectious laugh! The point, though, is that we empathize, and therefore cretae a connection through this motion, and want to feel that connection. One site writes, “According to 2012 research, yawns are most contagious among the closest of pals. ‘Researchers discovered that the closer you are to someone genetically or emotionally, the more likely it is that you’ll ‘catch’ their yawn,’ HuffPost Science reported. ”
Fun fact: The average yawn is about 6 seconds long, and, during it, the heart rate increases, although results between individuals can vary.
*Bonus: Yawning’s effects are different from just a deep breath. It is often more satisfying, too!*
So ta ta for now and I hope to see your chemical reaction soon!