View full lesson: http://ed.ted.com/lessons/why-do-we-itch-emma-bryce The average person experiences dozens of individual itches each day. We've all experienced the annoyance of an inconvenient...
========== You're standing at
the ready inside the goal when suddenly, you feel an intense itch
on the back of your head. We've all experienced the annoyance
of an inconvenient itch, but have you ever pondered why
we itch in the first place? The average person experiences
dozens of individual itches each day. They can be triggered by all sorts
of things, including allergic reactions, dryness, and even some diseases. And then there are the mysterious ones
that pop up for no reason at all, or just from talking about itching. You're scratching your head right now,
aren't you? Anyhow, let's take one of the most
common sources: bug bites. When a mosquito bites you, it releases a compound into your body
called an anticoagulant that prevents yo...