Y is for yawning

............because yawning is still a wonderful mystery in many ways and I'm grateful for that.

We know a yawn is a semi-automatic reflex that originates in the brain stem in response to a lower level of oxygen in the brain. Yawning does not necessarily indicate fatigue, although people do tend to yawn when they're sleepy.


Yawning is an action that occurs throughout the animal kingdom. Several different brain chemicals seem to be involved in yawning, but the mechanisms are still not understood.

For example, yawning seems to be contagious. Why is that? We simply don't know.

Here are a few things that are known about yawns:

• The average duration of a yawn is about 6 seconds.
• In humans, the earliest occurrence of a yawn happens at about 11 weeks after conception - (yes that's BEFORE the baby is born)
• Yawns become contagious to people between the first and second years of life.

 

So if you are over 2, you will probably find yourself yawning as you watch these videos!