Why do we get goose bumps?
Goose bumps are a vestige from the days when humans were covered with hair. When it's hot and you need to cool down, little muscles at the base of each hair relax. Your sweat glands pump out body heat. Your blood vessels get big to take more heat to the skin. When it's cold, the arrector muscle pulls the hair up. The duct to the sweat glands gets small to conserve heat. Our blood vessels also get small to save heat. Hair standing up doesn't make very good insulation - we don't have enough fur for that anymore. But those little muscles on the end of each hair still work, causing what we refer to as goose bumps.
Goose bumps are a vestige from the days when humans were covered with hair. When it's hot and you need to cool down, little muscles at the base of each hair relax. Your sweat glands pump out body heat. Your blood vessels get big to take more heat to the skin. When it's cold, the arrector muscle pulls the hair up. The duct to the sweat glands gets small to conserve heat. Our blood vessels also get small to save heat. Hair standing up doesn't make very good insulation - we don't have enough fur for that anymore. But those little muscles on the end of each hair still work, causing what we refer to as goose bumps.
Charles Mims
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