View full lesson: http://ed.ted.com/lessons/how-do-we-smell-rose-eveleth An adult human can distinguish up to 10000 odors. You use your nose to figure out what to eat, what to buy and even...
========== It's the first sense you use
when you're born.One out of every fifty of your genes
is dedicated to it.It must be important, right?Okay, take a deep breath
through your nose.It's your sense of smell,and it's breathtakingly powerful.As an adult, you can distinguish
about 10,000 different smells.Here's how your nose does it.Smell starts when you sniff molecules
from the air into your nostrils.95% of your nasal cavityis used just to filter that air
before it hits your lungs.But at the very back of your noseis a region called
the olfactory epithelium,a little patch of skin
that's key to everything you smell.The olfactory epithelium has
a layer of olfactory receptor cells,special neurons that sense smells,like the taste buds of y...
