Fig. 1.

Schematic of the human olfactory system. Odorants are transduced at the olfactory epithelium (1). Different receptor types (three illustrated, 1,000 in mammals) converge via the olfactory nerve onto common glomeruli at the olfactory bulb (2). From here information is conveyed via the lateral olfactory tract to primary olfactory cortex (3). From here, information is further relayed throughout the brain, most notably to orbitofrontal cortex (5) via a direct and indirect route through the thalamus (4)