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LET'S EXPLORE The human body

How do you smell and taste things?

A girl smelling a flowerA girl smelling a flowerSmells are tiny particles that flake off things and find their way up by your nose. The nose contains nerve cells that enable you to detect them. Tastes are picked up by nerve cells on your tongue. Smell particles from the food you are eating drift up from the back of your throat to your nose. In this way, your nose helps you taste things as well.


Cross-section through the headCross-section through the head

Smelling

Behind each nostril is an air passage, called the nasal cavity. This is about the size of your thumb. When nerve cells in the roof of the nasal cavity detect smell particles, they send messages along nerves to the brain. Sniffing draws extra air into the nasal cavity, making your sense of smell stronger. 

 

Inside the nose

Tiny hairs lining the inside of the noseTiny hairs lining the inside of the noseAs well as detecting smells, the nose also takes in air to breathe. It warms, moistens and filters the air before it travels to the lungs. Stiff hairs inside each nostril remove large particles of dust from the air. Mucus is a thick, sticky fluid that seeps out of the walls of the nasal cavity. It traps smaller particles, bacteria and viruses in the air we breathe. Sneezing removes particles that irritate the walls of the nasal cavity.

 

Tongue

There are 25 million smell sensors in the roof of the nasal cavity.

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