The Nose

Modified: 2026-08-06 7:42 PM CSDT

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.
- You have 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.
- It appears that those two species are much more dependent on their sense of smell than we are.
- We will look as some exceptions to that rule in humans in the next chapter.
- 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.