The Nose

Modified: 2024-06-19 2:33 PM CDST

• The nose is a transducer of volatile chemicals, or chemicals that are in the gaseous state.
  • Most, but not all, of the chemicals we smell are organic (composed of carbon molecules).
  • For us to be able to smell, the chemical must also be dissolvable in the nasal mucosa.
  • That is why you cannot smell as well as when you have a cold, there is too much nasal mucus.

• As a species, we depend on the sense of smell to a much lower degree than many other animals do.
  • One reason for this is the size of our olfactory apparatus.
  • It is relatively smaller than that of dogs and rats, for example (on a percentage basis). It appears that those two species are much more dependent on their sense of smell than we are.
• Note that the olfactory system is the only sense system that does not synapse through the thalamus. Rather it is connected directly to the cortex.