Where does the olfactory system begin?

Where does the olfactory system begin?

• A. In the brainstem.
• B. In the peripheral structures of the nasal cavity.
• C. In the tympanic cavity.
• D. In the cochlear duct.

Answer: (B)

Smell starts in the olfactory epithelium of the nasal cavity, where odor molecules bind to receptors on the cilia of olfactory receptor neurons. This peripheral sensory tissue converts chemical signals into neural impulses, with the axons traveling as the olfactory nerve through the cribriform plate to reach the olfactory bulb in the brain. The other options refer to structures involved in hearing (tympanic cavity, cochlear duct) or to processing centers further along the pathway (brainstem), but the initial detection happens in the peripheral structures of the nasal cavity.

Smell starts in the olfactory epithelium of the nasal cavity, where odor molecules bind to receptors on the cilia of olfactory receptor neurons. This peripheral sensory tissue converts chemical signals into neural impulses, with the axons traveling as the olfactory nerve through the cribriform plate to reach the olfactory bulb in the brain. The other options refer to structures involved in hearing (tympanic cavity, cochlear duct) or to processing centers further along the pathway (brainstem), but the initial detection happens in the peripheral structures of the nasal cavity.