A Sense Most Taken For Granted

For a long time, science paid only little attention to this most mystical and emotional of our senses. In Greek philosophy, the sense of smell was disqualified as being imprecise and emotional. Only in recent decades has this sense been more thoroughly researched.
First of all, it is only possible to smell what reaches the nose together with the air we breath – i.e. the substances have to be an a gaseous state. When we smell a fragrance strip, for example, we do not smell what is on it but what is no longer on it, i.e. what has evaporated and can be inhaled. Located in the nose are two olfactory mucous membranes, each approximately four square centimeters in size, which are densely packed with nerve cells. Extending from these cells are numerous
plunge processes, which protrude into the nasal cavity like tiny little hairs. Contained on these cilia are differently shaped receptors. When the air we inhale carries a molecule to the nasal mucous membrane, the molecule attaches to a matching
receptor, like a peg in a hole. Both its geometric shape as well as its electrical charge, its polarity, play a role in this connection. When a molecule “docks” with a matching receptor, an electrical signal – a stimulus – is sent to the brain.