The "It's Contagious!" Story

It was an ordinary day.  I talked Carol into watching the Phillies with me on the HD television.  Nearing 10 PM and the game is just about over.   I take a look at her to see if she is still awake.  

Carol and the sleeping Creamsicle.  

Sitting in her lap for the last two hours has been Creamsicle, our orange and white outdoor cat and ..... he is yawning.  I naturally yawn after seeing him do it.  Why is that?  Someone told me once that it means your brain isn't getting enough oxygen, but with the amount of times that I yawn my brain should be dead by now so that can't be true.  So, I "Googled" it.  One of the links led me to a doctor who I've seem published in our local paper under the name of Dr. K.  He said that one of his teachers in medical school speculated that yawning was a response to low oxygen or high carbon-dioxide levels.  When we open our mouths to breathe, we take in oxygen and expel carbon-dioxide.  But, Dr. K says his professor is full of it because yawning occurs even when oxygen and carbon dioxide levels are normal.  So maybe we yawn because we are tired.  Nah, that isn't true either, since we yawn in the morning after a night's sleep.  So, Dr. K gives a couple of his theories as to why we yawn.  (1) We have tiny air sacs in our lungs that can't go without air for long or they collapse.  So your body causes you to yawn to take in excessive air to refill those sacs.  Since your breathing is more shallow when you are tired it may cause you to yawn so you inhale the extra air. (2) If you are relaxed and your body needs to be more alert, you yawn to get the muscles and joints and heart rate going to prepare the body for action. (3) Seems that yawning may also be a sign of disease such as multiple sclerosis, ALS or Parkinson's disease, but this more than likely isn't the case with the majority of yawners.  (4) And the one that I really like ...... yawning is a nonverbal communication to others that it's time to relax, or head home.  So it seems that no one really knows why we yawn other than it is human nature to yawn.  And, it looks tonight as if it's more than just humans who yawn.  My guess is that Creamsicle is ready for bed.  It was another extraordinary day in the life of an ordinary guy.