Figure 1-9. The outer, inner, and middle ear.
Section IV. THE SPECIAL SENSE OF SMELL (OLFACTION)
The taste sensation is closely related to the sensation of smell. We often select
food and enjoy particular dishes because of a pleasant odor or aroma. A person with a
cold or allergies usually claims the food is tasteless. Actually, his sense of smell has
been affected and disturbed his sense of taste. There have been many attempts to
distinguish and classify the primary sensations of smells. One classification
distinguishes seven classes of primary sensations: camphoraceous, musky, floral,
pepperminty, ethereal, pungent, and putrid. Later research suggests that there may be
as many as fifty or more primary sensations of smell. Although animals have a more
highly developed sense of smell than humans, humans can identify at least 4000
different odors. Olfactory receptors become tired easily with the result that humans
cannot smell the same odor for very long, but they can pick up a new odor. Additionally,
a particular odor in an area of many odors can be identified, and an odor smelled only
once can often be remembered.