A couple of weeks ago I wrote about dandruff, bad breath, growling stomachs and body odor. Aside from the fact that none of these things are ever likely to be the subject of a blockbuster TV movie, they have something else in common: they’re all likely to embarrass us.
That segues nicely into this week’s column, which I call “Bodily Functions II: The Sequel,” and which begins with blushing (something those responsible for many of Hollywood’s sequels should be doing–but I digress).
Blushing isn’t perfectly understood, but it’s apparently related to the body’s reaction to stress, the “fight or flight” syndrome that floods us with adrenaline and other hormones whenever we’re in a dicey situation. “Fight or flight” is useful if the dicey situation is facing a sabre-toothed tiger on ye olde hunting grounds, but it doesn’t do us much good if the dicey situation is discovering one’s fly is open as one stands to deliver the keynote address at a black-tie dinner.
Part of “fight or flight” involves the pumping of additional blood to brain. The hypothalamus, which regulates body temperature, is located at the base of the brain and interprets this sudden surge of blood to the brain a sign of increased body temperature. It responds by routing more blood through the capillaries, tiny blood vessels close to the skin. The face has more of these than any other part of the body, so just like that, you’re red as a beet.
Embarrassment triggers blushing, but so does anger and other strong emotions. Some people blush more easily than others: that seems to be genetic. Blushing is most noticeable in people with fair skin, such as many redheads, but everyone blushes, regardless of skin color. Women blush more than men, though the reason could be cultural as much as physiological.
You can stop yourself from blushing by sipping cold liquid–the coldness in the mouth counteracts the hypothalamus’s assumption that the body is overheating. So nursing a cold drink at a party can help you hide the tell-tale blush of shyness (but only if the drink is non-alcoholic, because alcohol confuses your internal thermostat and usually causes blushing all by itself).
Another stress-related bodily function is butterflies in the stomach. At the same time your body pumps more blood to the brain, it constricts other blood vessels, which boosts blood pressure. This is probably what causes that tingly feeling in your gut.
Knees knocking from nervousness are also stress-related. The fight-or-flight flood of hormones literally overwhelms the muscles in your legs, which are expecting you, since you’re apparently facing a sabre-toothed tiger, to run away. Since what you’re really facing is a room full of strangers, and running away is not socially acceptable, your legs are all fired up with nowhere to go. The overstimulated muscles respond with spasming, and your knees knock together, or your hands tremble, or both.
One bodily function that’s not a product of stress but that can certainly cause it in those who share your sleeping quarters is snoring. Snoring is caused by air vibrating the soft palate, the back of the tongue and other soft parts of the respiratory passage: gooey bits flapping in the breeze, if you like. It tends to be worst when the snorer is sleeping on his back with his mouth open, because that maximizes the flow of air through those gooey bits. That’s why getting the snorer to roll over can help.
Snoring is normally just an annoyance (and only for other people: it doesn’t usually bother the snorers themselves much at all, which makes it even more annoying), but it can be a sign of apnea, a sometimes serious condition in which the sleeper periodically quits breathing.
Both snoring and apnea are most common in obese middle-aged men. Losing weight can help by reducing flab around the throat. Avoiding alcohol helps, too: alcohol relaxes the throat muscles, which enhances snoring.
Or you might try strapping a tennis ball to your back (or sewing one into a pocket on the back of your pajama top). This will keep you from sleeping on your back, and will also keep whoever is sharing your room off your back.
People who sleep with snorers inevitably spend a lot of time yawning. I mentioned yawning in my last column on bodily functions and described it as a reflex action which occurs when the brain stem detects too much carbon dioxide in the blood supply and tries to eliminate it by opening the mouth wide and expanding the chest cavity, to let carbon dioxide escape from the lungs and enable a large intake of oxygen-rich air.
With further reading, though, I’ve discovered there’s one small problem with this traditional explanation: it doesn’t account for a lot of the observed facts about yawning. In fact, studies have found little connection between yawning and levels of oxygen and carbon dioxide in the blood. Yawning also helps “pop” the ears by opening the eustachian tubes and equalizing pressure between the middle ear and the world outside, but that’s hardly likely to the be sole reason we do it, especially in Saskatchewan, where rapid changes in altitude aren’t too common.
Another suggested purpose for yawning is that it makes perks you up by contracting the facial muscles and increasing the flow of blood to the brain. But there’s no real scientific evidence for this explanation, either.
As everyone knows, even if they don’t speak Latin, “Cum enim qui videt alium ositare, ipse quoque ad oscitandum invitatur”–“One who yawns invited another to follow suit.” University of Maryland psychologist Robert Provine is a leading (maybe the only) yawn researcher. He had 37 adults sit in a soundproof cubicle for half an hour and think about yawning. They had to press a button whenever they yawned and keep it depressed for the duration of the yawn. The average yawn turned out to last 5.9 seconds (ranging from four to 11 seconds), the average number of yawns was 28, with a low of 1 and a high of 76, and the average “interyawn” interval was 68.3 seconds. I’m not sure what that proves, but it’s interesting.
He also had the subjects watch videotapes of an actor who yawned 30 times and another actor who smiled 30 times, to see if seeing someone yawn really triggers yawning (it does). Then he had them read passages about yawning or about hiccupping . Those who read about yawning reported more yawns than those who read about hiccupping.
His research continues: it seems that yawning is not, after all, an open-and-shut case.
Perhaps I may yet have to write “Bodily Functions III: The Saga Continues.”
