14. Yawns Are Like Soap For The Blood
Keep in mind that yawns are big breaths that you take instinctively. While your brain may be responding to social and neurological cues, there are often less profound reasons for why we yawn. One is that we just need more oxygen and need to expel more carbon dioxide.
Oxygen helps cleanse the blood by removing impurities. Taking in a great big yawn supercharges this cleansing process by infusing the blood with an influx of oxygen. This means that while your mouth is open in a yawn, it basically acts as a giant filter.