Scents determine our lives, as the well-known gastronomy and wine expert Guy Bonnefoit writes in his book "Fascination Wine & Aromas": The human skin has a surface area of about two square metres and has up to 300 olfactory components. Depending on the physical condition and state of mind, the olfactory substances also change. A dog can distinguish precisely between people who are well-disposed towards it and those who are anxious towards it. Every mood has its own smell - thus one can smell the state "happy". An experienced country doctor reports that he is able to recognise certain illnesses when entering a sickroom. Each disease develops its own typical "scent". Diabetes smells fruity, diphtheria sweetish, typhoid like baked bread and gout like a lion's cage or a pet shop.
Behavioural biology
The sense of smell is the ability to perceive gaseous substances or substances dissolved in water at the molecular level. Like taste, smell is one of the chemical senses. The ability has only been proven in vertebrates and insects. Olfactory perceptions, more than all other sensory organs, are very strongly emotional. They are immediately evaluated as pleasant (smelly) or unpleasant (stinky). In behavioural biology, smell has a special significance with regard to food intake, reproductive behaviour and recognition of enemies. Odours stimulate appetite and the formation of digestive juices. The statement "that you can't smell someone" is much more than just a play on words.
When it comes to choosing a partner, smell unconsciously plays a major role. Likewise, smells play an important role in memory and associative brain processes. Smells are perceived olfactorily via the yellow olfactory mucosa (about 2 x 5 cm²) in the uppermost part of the nasal cavity directly below the brain. However, scents are not only conducted and perceived nasally (orthonasally, pronasally) when inhaling via the two nostrils, but also retronasally when exhaling from the oral cavity via the nasopharynx to the olfactory mucosa. It depends on the amount of an odorant when it is perceived. This is called the Wahrnehmungs-Schwelleperception...
