Doctor Eclectic

Doctor Eclectic
Doctor Eclectic

Friday, April 6, 2012

Did You Know?

My wife, Mary serves as my clipping service for everything except the Wall Street Journal, where I return the favor.  She is one of those rare breeds who still reads two papers a day, Time magazine from cover to cover and similarly handles The New Yorker, to which we have a recurring subscription since it was first published.  In addition to the WSJ, I accumulate and eventually browse the Rolling Stone, to which I have subscribed almost from the first issue.

So, it was not unusual when she gave me a Parade Magazine and told me I would find an article interesting.  It was titled “Your Body Explained” and gave 16 examples of questions often asked about why our bodies act the way they do.  In one of those strange coincidences my WSJ also had a short article covering one question I had been curious about and found answered during my second bout with graduate school by an Anatomy Professor from Georgetown.

I found two of the 16 of particular interest:  “Why do we cry when cutting onions?’ and “Why do we get goose bumps when watching scary movies?” for different reasons.  A third, which peripherally found its way into the WSJ article, was interesting because it caused me to remember my quest as to “why do some people sneeze when they look at a light (or the sun)?”

One of my sister-in-laws writes a Blog that is an email letter to her rather large family and extended relatives and friends.  In a recent posting she mentioned that my brother-in-law tears when he cuts onions.  She had heard of some old-wife’s tale, which as I remember claimed that if you held your lip or your tongue you wouldn’t tear. It didn’t seem to work, which prompted Dave to think, "Maybe you have to hold it with both hands?” (This would probably prevent you from cutting the onion.)

I learned a trick at a cooking class that seems to have solved my onion-and-tears issue.  You peel the skin of the onion to a depth where you would use all that you cut.  Then slice through the top of the onion, stopping short of the base.  Then make a cut diagonal to the first, and then keep making cuts through the halves, then the quarters, then the eighths.  In large onions you might get to sixteenths.  Then turning the prepared onion on its side, you slice at right angles to your cuts, effectively making “chops” that are just the right size.  With a little experience you cut just deep enough for the cup or ½ cup called for in the recipe.

The scary movie goose bumps was interesting because I knew that cold caused the piloerection reflex that increases body surface to make you feel warmer.  But the reason for the reflex to kick in when you are frightened is the body’s reaction to fear, making you appear larger to that which frightens you, much as a cat will fluff its fur when it senses danger.

From an early age I remember being able to trigger a sneeze by looking at the sun.  My sister couldn’t do it, and took great joy in telling her it was something she could learn to do, if she were smarter.  Childish, true, but she could do one of those shrill whistles that will get you a cab on rainy days in Manhattan and I couldn’t.  She also could throw her leg over my head for several years after I reached my full height of 5’6”.

But I didn’t learn why I had that ability until eight years after I graduated from Dental School, when I was in a post-graduate program and in a class taught by the older Anatomy Professor from Georgetown.  He asked for questions and I asked for a solution to my puzzle.

“It has to do with the Vagal nerve and where the lacrimal duct empties into the nose.”  When man decided to stand up and walk some 1.5 million years ago his tears no longer benignly flowed from his eyes through his nose.  Instead, if his lacrimal gland emptied above the Vagal nerve, those tears would simulate the nerve and cause a sneeze reflex.  This placement is true for about half the American population. (I took his word for that, but it seemed true in my family.)

The only problem with that type of knowledge is it’s hard to fit into normal conversation.  Even the WSJ couched it with a vague comment that tears can stimulate a sneeze.

Next Post I’ll explain why I’m getting tired of “Myanmar, also known as Burma” and what I found about that…

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