What role do cilia play in detecting odors?

In the olfactory system, cilia play a critical role in the detection of odors by serving as the site where olfactory receptor proteins are concentrated.1

Each olfactory receptor cell features a peripheral dendrite that extends to the surface of the olfactory epithelium, where it gives rise to these long, slender, hair-like extensions known as cilia. These cilia are bathed in the mucus of the nasal cavity, which facilitates the interaction between odor molecules and the receptors.231

The cilia are essential for the following reasons:
* Receptor Density: Each receptor cell possesses many thousands of a specific type of receptor protein located on the membrane of its exposed cilia.1
* Chemical Interaction: Sensations of smell occur when chemical substances dissolve in the fluid layer covering the mucous membrane and come into contact with these cilia.3
* Signal Initiation: When an odor molecule binds to a receptor protein on the cilia, the protein undergoes a conformational change that triggers a sequence of chemical events, ultimately leading to the production of action potentials that convey information to the brain.1