Yawning is a natural phenomenon that can be observed in humans and animals. We assume that boredom and tiredness triggers yawning. To understand the causes of yawning you will have to delve a little deeper. Even the baby in womb is noted to be yawning. Nobody can escape yawning. It is also amusing how people start yawning when they see someone else yawning nearby. Yawning feels quite pleasant as it feels our chest with fresh air. People tend to yawn by opening their mouth and drawing in as much air as they can. We do not learn to yawn. It is an involuntary reaction that we know inherently.
It might sound very strange to you but scientific studies show that yawning stems from sexual arousal. Though we have always related it to boredom, even excitement can make us yawn. A fetus can yawn when it reaches 11 months. The blood flow through our heart gets increased due to yawning. In the whole process many of our body parts have to toil. The lungs and upper body cavity expands, the mouth gets opened and we draw in air by moving the diaphragm.
We yawn when our body or mind is very tired or exhausted. This happens because the amount of oxygen in our body decreases fast when we are tired. We do not breathe properly while bored or tired. The involuntary reaction of our body is to make us yawn so that we get sufficient oxygen and feel better. Yawning occurs when our brain needs more blood flow. It decreases the temperature of our brain and helps our head function better. Some consider yawning something we do as we have evolved from the apes that used to do yawning movements of the mouth to scare away the predators or enemies.
