Smell and taste

Mmm, smells so good! Lovely! I can't smell anything. I have a cold, as always. Yeah, but you can taste it, right?

Mm, but it's not as nice as it normally is. No, it's not as nice as it's normally is. Smell and taste are connected. They co-operate and reinforce each other. When you eat an apple pie with cinnamon, the smell of the cinnamon makes the taste better.

If you don't get the smell, it doesn't taste fully. Try for yourself the next time you eat cinnamon. Hold your nose and see if it tastes the same. -- But what are smell and taste? How do they work? Taste is perceived in the mouth.

There you find sensory cells that are grouped in taste buds. There are thousands, most of them on the tongue. The taste buds react to substances and send signals to the brain. There are five basic tastes that a human being is able to detect. Sweet is nice, for most of us.

That's because a sweet taste means sugar, which contains lots of energy. And energy is vital for us. Salt too is mostly perceived as something positive. Salt in the right amount is also vital for our bodies. Sour can also be something positive, but too strong a sour taste is a warning signal.

We don't like that. The warning can be about food that's gone rotten or fruit that's not ripe. Bitter is also a warning signal. Poisonous plants and other toxic substances often have a bitter taste. The fifth flavour is umami, which means savory.

It's often found in food like mushrooms or broth. So, a human is able to detect only five different tastes. But the number of smells that we can detect is many times bigger. Ten thousands of different smells can be distinguished by our sense of smell. That sounds a lot, but yet it's relatively few, compared to most mammals.

Dogs, for instance, have a sense of smell that is far superior to man's, and that's why they are used for tracking. In the nose, there are a hundred million cells, that react when they meet various smell molecules. Each smell cell has a receptor sensitive to its own specific molecule. The molecule is bound to the cell and activates an electric signal that is transmitted to the brain. Different smells are created by specific combinations of different smell molecules.

And it's the ability to detect combinations that makes it possible to distinguish so many smells. The sense of smell is important to us. Smell, or scent, often carries strong memories. It can make us think of places or people that mean a lot to us, but it may also remind us of unpleasant experiences. Some scent memories follow us throughout our lives.

Have you yourself experienced how a certain scent can steer your thought to your grandparents' home, or to a toy you had when you were younger? Scent also affects how people react to each other, often without us knowing. Even a newborn child can recognise the scent of its mother and distinguish it from the scent of other women. And, as mentioned, smell and taste co-operate, making the sensation of nice food or drink so much stronger than smell alone can. But hey, if you don't like this, then I might as well have the whole cake.

Nonono! My sense of taste is working fine! Unlike your sense of fair play!