What gives you goose bumps?
"Sometimes when I'm reading a scary book I start to sweat," says 12-year-old Tommy Bill, from Virginia Beach, Va. When we're absorbed in the spooky stuff happening to characters in a horror story or movie, we might not even notice that strange things are happening to us.
When you're frightened, your body goes through complex changes that prepare you to stay and fight . . . or get away fast. This is known as the fight-or-flight response, says Dr. Ned Kalin, a professor of psychiatry at the University of Wisconsin-Madison Medical School. Humans have always been equipped with this automatic response. Kalin says it helps us cope with danger, such as coming face-to-face with a wild animal--or an overbearing gym teacher.
But isn't confronting a crazed creature different from reading about one? Not really, Kalin says. "The same systems in your brain and throughout your body are activated whether the cause of your fear is real or imagined," he explains. When we read or watch a movie, the brain perceives the ideas and images as scary and activates other organs.
SKIN THAT GOES BUMP
The fear message stimulates a branch of the nervous system called the autonomic nervous system. This part of the nervous system controls your body's involuntary functions, such as your heartbeat and breathing. The autonomic nervous system also controls many glands. These are organs that produce hormones, chemicals that carry messages from one part of the body to another.
When you're afraid, the adrenal glands (located above the kidneys) start pumping out the hormone adrenaline (also know as epinephrine), as well as several other hormones. Your nervous system and these hormones trigger several reactions to prepare your body to fight or flee (see The Fight-or-Flight Response).
But what about goose bumps, made famous by Goosebumps author R. L. Stine? Does "chicken skin" serve any useful purpose when you're feeling chicken?
Scientists think it used to-at least for our fur-covered ancestors. Here's why: Goosebumps form when adrenaline causes contractions of tiny muscles attached to each hair. The muscles pull the hairs up and the hairs pull the skin. If you've ever seen a cat with its fur puffed up, you've seen what goose bumps can do. They make an animal appear bigger than it really is. That might make a predator think twice before attacking.
You may also get goose bUmps when you get a chill from your thrill. Being afraid can make You sweat--which cools you off. The raised hairs that produce goose bumps are an attempt to trap air and body heat.
THAT'S USING YOUR HEAD
So how do you calm yourself after a scare? Use your head! When you remind yourself that the source of your fright isn't real, the brain sends a calling message to the rest of your body. And without you knowing it, your autonomic nervous system begins to reverse the effects of fright. Whew! What a relief!
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|Title Annotation:||includes a chart on the flight-or-fight response|
|Date:||Oct 18, 1996|
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