SMELL

Humans have a very keen sense of smell: we can detect thousands of different smells. This ability relies on the presence of special sensory receptors in the upper part of the nose. When stimulated by odour molecules, these receptors send signals along nerves to the brain for processing. Sometimes odour molecules do not reach the sensory area, but sniffing will help get them there.

SMELL RECEPTOR CELLS IN ROOF OF NOSE

Smell receptors are specialized nerve cells. Each bears many tiny cilia (hairs), which project into the space in the upper part of the nose. A nerve fibre extends from the other end of each cell. This joins other fibres to form the olfactory nerves, which carry signals to the brain.

CILIA OF SMELL RECEPTOR CELL

The cilia can detect tiny amounts of substances in the air, though molecules of those substances must first be absorbed by the mucus layer. There they interact with the cilia to trigger nerve impulses.

FIND OUT MORE

Nervous System

Copyright © 2007 Dorling Kindersley

highlights

Teens and E-Cigarettes: 6 Things You Must Know
For the first time in a generation, tobacco use has risen among the nation's youth, due to the rising use of e-cigarettes. Learn more about the dangerous and addictive e-cigarette trend, and get tips to talk to your teen.

Find Today's Newest & Best Children's Books!
Looking for newly released books for your child? Try our new Book Finder tool to search for new books by age, type, and theme, brought to you by Galactic Hot Dogs.

Printable Lists of the Top 100 Baby Names
Need help with baby name ideas? Use our printable list of the top 100 girl names and top 100 boy names of 2015 to help you brainstorm and narrow down your favorites.

Registered for Kindergarten — Now What?
Wondering what to do now that you've signed your child up for kindergarten? Try our award-winning Kindergarten Readiness app! This easy-to-use checklist comes with games and activities to help your child build essential skills for kindergarten. Download the Kindergarten Readiness app today!

stay connected

Sign up for our free email newsletters and receive the latest advice and information on all things parenting.

Enter your email address to sign up or manage your account.

Facebook icon Facebook icon Follow Us on Pinterest

editor’s picks