2 OLFACTORY PERCEPTION 2.1 Anatomy of the Olfactory System The olfactory system(Figure 17.1) is a unique sensory system in which the cells respon- sible for the receipt and transduction of odorous stimuli also transmit encoded information to the brain. Olfactory receptor cells act to process and not merely relay information. In humans, these cells can number in the billions. They are interspersed among supporting and basal cells in a yellow-pigmented epithelium called the olfactory mucosa, located in the upper part of the nasal cavity. Research on other species suggests that basal cells divide