The Smell, that Forgotten Sense

A single particle of a certain fragrance is able to open the appetite, announce danger, arouse sexual desire, evoke the most remote sensations, and recall experiences and/or emotions of the distant past. But speaking of odors, it is interesting to say that each being has the genes that code the receptors of their smell and those that code for the odors emanating from their body. The genetic variations of HCM (Major his to compatibility complex, when determining changes in the production of odorous metabolites; explain the odors associated to specific HCM types. From the above it is inferred that each individual has its characteristic odor. We think we smell with the nose, but this is like saying that we hear with the earlobe. In fact, the part of the nose that we can see from the outside serves only to receive and channel the air that contains the odoriferous molecules. The neurons that perceive these molecules, are in the depth of the nasal cavity, in a portion of cells called olfactory epithelium. Perched behind a closed curve type, on the roof of the nasal cavity, is the olfactory epithelium, which only measures a few square centimeters. It contains about 5 million olfactory neurons, in addition to their supporting cells and stem cells. In fact, there are two portions of olfactory epithelium (one on each side of the nose) that lie in a horizontal line, just below the level of the eyes (Figure 1).