Final answer:
The olfactory nerves carry sensory information from the olfactory bulbs to the primary olfactory cortex. Olfactory neurons in the nasal cavity detect odors and send signals through the olfactory tract to the brain. Unlike other senses, olfaction is processed directly in the cortex, leading to strong memory and emotional connections.
Step-by-step explanation:
The correct word to fill in the blank in the student's question is "nerves." Thus, the complete sentence reads, The olfactory nerves carry sensory information from the olfactory bulbs to the primary olfactory cortex.
Olfactory neurons are specialized cells found in the olfactory epithelium at the top of the nasal cavity. These cells have hair-like cilia that contain receptors specialized to detect different odorants. When an odorant binds with a receptor, it induces a chemical change, prompting these neurons to send signals through their axons. These axons extend into the brain through the cribriform plate and collectively form the olfactory tract. The olfactory tract connects to the olfactory bulb situated on the brain's ventral surface. From the olfactory bulb, the signal is carried to several brain regions, including the primary olfactory cortex, located near the amygdala and the gustatory cortex.
Olfaction is unique among the senses in that it does not involve the thalamus before reaching the cerebral cortex. The direct transmission pathway to the cortex allows for a strong connection with memory and emotion, which is why smells can trigger vivid memories and emotional responses.