Final answer:
Olfactory information travels from the olfactory bulb to the primary olfactory cortex, the amygdala, and the limbic system, without passing through the thalamus, which makes the sense of smell a direct trigger for memory and emotion.
Step-by-step explanation:
Olfactory information travels from the olfactory bulb to several key areas within the brain after initial detection by olfactory receptor cells in the nasal cavity. These receptor cells detect odor molecules, initiate a signal, and send it through the olfactory bulb, which acts as a relay station. From the olfactory bulb, the information is then conveyed to different regions, particularly the primary olfactory cortex located in the temporal lobe, and other areas involved in memory and emotions such as the amygdala and the limbic system.
Unlike other sensory pathways, the olfactory pathway does not pass through the thalamus before reaching the cerebral cortex. This direct transmission route to the cortex is one reason why smells can strongly evoke memories and emotions. Various brain regions process olfactory information for different purposes, contributing to the complexity and significance of our sense of smell.