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

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 Twitter icon Follow Us on Pinterest

editor’s picks

highlights

Pin the Star on the Christmas Tree Game
Looking for a great Christmas game to play with your kids? Print our free Pin the Star on the Christmas Tree game for loads of family fun!

Kindergarten Readiness App Wins Gold
Our Kindergarten Readiness app won the Gold Award of Excellence in the educational category at the 2014 Communicator Awards. This valuable checklist comes with games and activities to help your child practice the essential skills she needs for kindergarten. Download the Kindergarten Readiness app today!

Top Family Movies in Theaters for the Holidays
Taking the kids to the movies is a special family treat for the holidays! Don't miss 2014's best family films in theaters from Thanksgiving through Christmas.

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, and create reading lists for kids!