Sunday, February 27, 2011

Why do we sneeze?

From the book: "Why Do Men Leave The Seat Up?"


"Gesundheit! You just had a sternutation."

"A what?"

"Sternutation. That's the medical term for sneeze."

How did you manage to do that? Chances are, a small particle founds its way into your nose. It might have been a bit of pollen, dust, bacteria, a virus, a mite, smoke, or another irritant. Once the nerve cells in the mucous membranes of your nose got wind of it, they released chemicals called histamines. These chemicals acted as messengers, speeding straight to the sneeze center in your brain. (Yes, you really do have a special "sneeze center", located in the area of the brain that connects to the spinal cord, known as the medulla oblongata.) The histamines alerted your brain to the presence of the nasal invaders, and the brain set your body's defense system in motion.

First, your vocal cords closed, causing pressure to build up in your chest & lungs. The pressure built and built and built, and just when you couldn't hold it any longer, your diaphragm contracted, your eyes shut, your vocal cords snapped open, and air came whooshing out of your mouth and nose at nearly one hundred miles per hour, hopefully carrying the offending particles with it.

Incidentally, sometimes a sneeze begins not in the nose, but in the eyes.

**to read the rest of this entry... 

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