Yawning

In the people point of view, yawning happen when they're feel sleepy. Actually yawning occur when human body have insufficient amount of oxygen. When the body is in insufficient amount of oxigen,it will alert the brain to do the next action which is yawning activity. As a result, a lot of oxygen will inhale into the body until the amount are required. Thats why when yawning,the mouth will open for quite a long time to gather sufficient amount of oxygen. Human can avoid the yawning effect by taking a deep breath at least 3 times once a hour.Drinking a lot of plain water also can help to reduce yawning symptom.