Humans possess five senses: sight, sound, touch, taste, and smell. Taste and smell are also referred to as chemical senses because they provide us with information about changes in the chemistry of our environment.
Chemical senses are the oldest of our senses and are used by all animals, including man, to survive in an environment. Our sense of smell is used for many reasons, including the following:
* Communication and recognition
Regarding communication, pheromones are scent-signals between members of the same species, while allelochemicals are scent-signals between members of different species.
Regarding recognition, a baby can recognize its mother by the way she smells, and vice versa.
* Finding food
Our sense of smell can also be used to find food and assess its quality. The chemical degradation of food produces chemicals known as amines. This is why rancid food smells bad. It is our signal not to eat that food even if it looks perfectly fine.
* Defense
Smells can also be a defense mechanism. We can smell smoke long before we can see the flames of a fire. We have also added a smelly chemical called mercaptan to natural gas so we can smell a gas leak in our home even if there is no sound or the gas is invisible to the naked eye.
* Pleasure
Studies have shown that the smell of something can produce feelings of pleasure or displeasure. This is because our sense of smell is closely related to the part of the brain that controls our feelings and emotions.
* Memory
A smell can also trigger a memory quickly and accurately. This is because the scent-signals in the brain go directly to the part of the brain that deals with memory and emotion.
Our sense of smell is particularly important to our quality of life. When choosing our fragrances for our beauty products, we want to produce feelings of pleasure on the part of the consumer.
