Hint: Yawning is opening a wide mouth. Firstly, we draw more air while yawning and then we exhale that air. When our body feels tired or lacks sleep or sleepy condition we yawn. Also yawning is a reflex action when we see other people in our surrounding yawning we also tend to yawn. Our mind immediately directs the action. So, we don’t have any control over that action.
Complete answer: When we yawn, we feel a certain kind of relaxation as yawning is a process where our brain cells lack sufficient oxygen. The deep breath we take while yawning is to help us draw in more oxygen and supply the much-needed oxygen to the tired, drowsy body organs including our brain. Yawning does help our body as when we feel bored or sleepy our amount of breathing oxygen becomes less as compared to the normal breathing in other times. It is similar to the fact like panting when we pant- our body needs more oxygen so we take oxygen not only from the nose but from the mouth too. The same mechanism applies here in yawning. The amount of carbon dioxide starts to increase in lungs so to decrease the level of carbon dioxide and increase or supply a high amount of oxygen yawning is required. While excessive boredom is often attributed to sleepiness or forbearance, this can be a symptom of a basic medical problem. Some conditions may cause a vasovagal reaction, resulting in excessive yeast. During a vasovagal reaction, there’s increased activity in the vagus nerve. In addition, different regions of the brain control yawning and breathing. Low oxygen levels in the brain hypothalamus can still induce yawning in the paraventricular nucleus (PVN). We discussed the reason behind yawning but there is another fact about yawning to be noticed is while a person yawns, eyes produce tears while yawning. This is because as we know eyes need to stay wet, so these glands produce tears all the time. So, when we yawn, our face muscles contract and put pressure on the tear glands which are lacrimal glands. Lachrymal glands produce tears in our eyes so, this causes them to release excess tears as due to face contraction. An average yawn lasts up to six seconds during those six seconds heart rate increases significantly.
Note: On average a person or adult yawns \[20\] times per day. And when a person feels a yawn coming up it can nearly become impossible to suppress. You can suppress a sneeze but yawn is not possible. Excessive yawning can be a sign of bleeding around the heart or even a heart attack. The vagus nerve runs down your heart and stomach from the bottom of your brain.