Which of the following is true about the olfactory system?
The olfactory epithelium has a mucous layer so, only water-soluble odour molecules will pass through.
The olfactory epithelium is involved in the first step of the sense of smell. It has a mucous layer covering the chemoreceptors. This mucous layer makes sure that only water-soluble odour molecules are able to pass through it easily and activate the chemoreceptors that are involved in the sensation of smell.