Larry
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Goose bumps are a bodily phenomenon that happens to all mammals, not just people. They are also known as goose pimples, chicken skin, goose flesh, and chill bumps, but doctors call them cutis anserina. The reflex that causes goose bumps to appear is known as piloerection or horripilation. Goose bumps are caused by little muscles, called arrectores pilorum, under the skin where each of our hairs grows. When these muscles contract, they form little bumps, just like when you flex your arm muscles, except, of course, the bumps are much larger. When the muscles contract, they make the hair at the site stand up straight and erect. Goose bumps can occur for several different reasons. They are controlled by our autonomic nervous system, which means they act on their own, and we don’t have to think about making them work. When it is cold, our body flexes the arrectores pilorum to make our hairs stand up on end. When our hairs stand up, they form a layer of insulation over our skin that helps to keep our body heat in and the cold out. Although our body hair is minimal now, it is theorized that humans once had thicker body hair and goose bumps had more effect than it does now.
In addition to being cold, goose bumps can be caused by strong emotions such as anger and fear. This is part of our fight-or-flight response to possible danger. Mammals that have a lot of hair appear much larger when their hair stands up. A prime example of this is in porcupines. When they sense danger, their quills stand on end for protection. In people, goose bumps can also be triggered by excitement. Studies have found that even remembering times of great joy can give us goose bumps.
 Posted 5398 day ago
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