One of the five senses : Smell

by Caroline, Alexandra, Phoebe, & Andrew

Olfaction is another word for sense of smell.

Specialized receptor cells of the olfactory epithelium detect and recognize smells.

Your nose is a huge cavity built to smell, moisten, and filter the air you breathe. When you breathe in, the tiny hairs, called cilia, act like a broom and filter everything trying to get into your nose; from dust particles to bugs.

The air passes through the nasal cavity and though a thick layer of mucous to the olfactory bulb. Each odour particle has a receptor that is recognized by a nerve cell. The cells then send signals to the brain via the olfactory nerve. The brain then interprets those molecules as the sweet flowers, or  pie.

Humans can detect over 10,000 different smells. The olfactory nerve picks up the scents from the air you breathe and translate them into nerve impulses or messages that are then sent to the olfactory bulb located in the front of the brain.

Actually, how and why we smell is still inadequately known.

Random Facts:

-Anosmia is a condition where someone can’t sense smells

-your sense of smell gets worse as you age

–dogs have 1 million smell cells/nostril which are 100x bigger than humans

source:

http://library.thinkquest.org/3750/smell/smell.html
http://en.wikipedia.org/wiki/Olfaction