Sensory Systems
Sensory systems are the parts of your body that let you see, hear, smell, taste, and touch.
Five bowls sit on a kitchen counter. Each catches one thing: light, sound, scent, flavor, or touch. A tube runs from each bowl to a box in the middle. Your senses work that way — each has its own catcher that sends signals to your brain.
Explaining sensory systems by grade level
Hold your nose and try to taste a piece of candy. It is hard to tell the flavor. Let go of your nose and the taste comes back. Your nose and tongue work as a team. When one sense is blocked, the others can not do the full job alone.
Projects that explore sensory systems
Your sensory systems for smell and taste work together. About 80 to 90 percent of what you perceive as taste actually comes from your sense of smell. Block the nose and flavor nearly vanishes, showing how much these two senses depend on each other.
Your nose can recognize thousands of scents, but some smells are much harder to tell apart than others. To test this, collect items with strong scents — coffee, chocolate, garlic, and mint are good choices. Place each in a separate container with a hole in the lid. Blindfold a volunteer and ask them to sniff each container, guess the item, and rate how strong the smell is. After testing several people, compare the results. Common and distinct smells like coffee and chocolate are easier to identify. Similar smells like sawdust and pencil shavings are often confused.
The tongue does not respond to every flavor equally. Blindfolded participants tasted four samples one at a time — sugar, salt, lime juice, and bitter chocolate — rinsing between each. They reported which taste felt the most intense. Most identified bitter chocolate as the strongest. The results show that the tongue may be more sensitive to bitter flavors than to sweet, salty, or sour ones.
Smell and taste work together to help you identify food. Blocking one sense can make the other much harder to use. You blindfold three or more volunteers, have them plug their noses, and give each person small spoonfuls of different baby foods to name. After testing all the foods with noses plugged, you remove the nose plug and repeat. Comparing the two rounds shows exactly how much smell contributes to tasting — and how much harder it is to identify flavors without it.