Monday, 13 May 2013

What makes us 'YAWN'?

Before getting into the explanation, let me tell you what made me to write this article. Today (May 13, 2013), I have been yawning continuously since evening. Every time I yawned, I thought about writing the 'yawn mechanism' in my blog and here is the result. 

The 'yawn' mechanism
Normally, when we breathe in, we inhale oxygen which is used by the body. The body also makes carbon dioxide which is exhaled through the lungs. When we are sleepy, bored or tired, we breathe more slowly and the oxygen supply in our body is therefore reduced. On noticing this, the brain sends a message to the lungs and that in turn makes us to take an extra deep, long breathe called the 'yawn'. It pumps in more oxygen into our body and gives out carbon dioxide fully.

Yawning is an involuntary action caused due to lack of required oxygen supply in our body. Many parts of the body are in action when we yawn. First, our mouth opens, jaw drops, allowing as much air as possible to be taken in. Then the air is filled in lungs. Our abdominal muscles flex and the diaphragm is pushed down. The lungs gets expanded and the excess air is blown back out. 

After reading the article, you might find yourself yawning or you might have yawned a couple of times while reading it. In fact, I yawned more than thrice while writing this.  


  1. Caution while yawning is don't open mouth to the maximum extent possible, sometimes jaws may be displaced from their location, rare case though!!!

  2. A yawn is very contagious. Even if you see, hear or read about a yawn, you actually start yawning!!