All five senses (taste, touch, sight, smell and sound) are connected to the brain. Each sense sends a message to the brain along different pathways in your body, called nerves. Once the brain receives the message, it then decides what to do about it.
Sight
Your eyes work a bit like a camcorder, taking moving pictures and sending those pictures to the brain. The black circle in the middle of your eye is actually a little hole, letting light into the eye. At the back of your eye are tiny things called receptors; one for sending messages about bright light and colour (cones), and one for dim light (rods). Only rods work in low light, which is why you can’t see colours when it’s dark.
Hearing
Because of their special shape, your ears draw in all the different sounds you hear every day. Those sounds travel along a little tunnel inside your ears, and bounce off a tiny piece of skin stretched across the tunnel called the ear drum. Each sound makes the ear drum vibrate, and those vibrations travel up to the brain, which tells you what the sound is.
Touch
Like your eyes, your skin also has lots of tiny receptors, but instead of helping you to see, these receptors tell you if something is hot, cold, painful, tickly and lots of other different things. Your hands, lips and the bottom of your feet are especially sensitive. For example, if you put your hand near a hot stove, the receptor sends a message to the brain and you know right away not to touch it or else you will get hurt.
Smell
Close your eyes and imagine you have a yummy chocolate cake in front of you. How could you tell it was a chocolate cake if you couldn’t see it? When you have a big sniff, the air flows into your nose and over tiny hairs at the top of the nostrils. The hairs send messages about what you smell to your brain. If you have a cold, the hairs get clogged up with mucus, and you can’t smell anything.
Taste
Your tongue is covered in tiny little bumps called taste buds. Each part of your tongue can taste a different flavour – sweet, bitter, sour and salty. When you eat something, the taste buds send a message along the nerves to the brain, and the brain recognizes what you are eating. Like your skin, your tongue also has receptors, and can tell you if something is too hot to eat, or something that might be dangerous if you tried to swallow it, like a fish bone.
The book also looks at different animal senses - how well cats can see in the dark, what a sensitive nose a dog has, and how fish can sense other fish, whether it's their next meal, or another fish that might want to eat them.
How Do Your Senses Work? (Usborne Publishing, 2007, ISBN 0 7460 2506 8) is a child-friendly, informative book combining clever lift-the-flap illustrations and basic scientific facts. Other titles in the series include How Are Babies Made and What Happens to Your Food?
