The sense of smell

The sense of smell is the perception of the smell and the ability to distinguish smells, the substances that are spread in the air or in the water. The science about the sense of smell is called odorimetry.

The perception of smells can't be measured directly. To do that people use unusual methods and other characteristics of the smell such as intensiveness, odour threshold (what the concentration should be so that the person could feel the smell), and the compare of the smell with other smells. Usually there is the direct dependence between the odour threshold and apprehensibility.

There are a lot of disorders of the sense of the smell as well as natural individual decrease of the ability to sense the smell. But sometimes it is decreased under the influence of special factors and may lead even to anosmia.

From the evolution point of view, one of the most ancient and important senses is the sense of smell with the help of which animals have the possibility to orient in the world. This sense was the ancestor of other senses and with the help of it animals had the possibility to get to know where the food is without seeing it as well as the presence of representatives of another sex and the appearance of the danger. But people have less developed sense of the smell.