Ever wondered why you instinctively scratch an itch? Scratching does more than satisfy an itch. It’s your body’s main line of defense against skin invaders. An irritant triggers nerve receptors on the skin to send an alert to the brain. The brain then deploys fingernails back to the itch site, where the friction from nails on skin unseats the invader. A scratch is born. Visit www.GetScience.com to learn more.

Bodily Functions Explained: Itch & Scratch (Get Science)

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