The Yawn

The Yawn is one of biological Mysteries Scientists Still Can't Explain. Everyone used to do nothing more than yawn. In reality, it is something that most people do on a daily basis, and it has been noticed in other species such as dogs, apes, and even reptiles. It's a response where you take in a lot of air, expand your eardrum, and then exhale. People frequently extend their limbs as well, and this combination is known as limb stretch. However, the topic of why people do it remains unanswered.

The theory that individuals yawn to get rid of "bad air" has been around since ancient times, when Hippocrates proposed that it was done to get rid of "bad air." Then, in the 18th century, scientists developed a slightly more scientific view, claiming that yawning was a mechanism for the body to increase the amount of oxygen in the blood, causing the heart rate to increase and the body to become more alert. This theory is now debunked, as contemporary testing reveal no increase in oxygen after yawning. At the moment, the favored hypothesis suggests that yawning is used to cool down the brain, but it still remains an uncertain topic that will need more research before a conclusive answer