What is the pathway for smell physiology once an odorant binds to a receptor?

The correct sequence of the pathway for smell physiology upon odorant binding to a receptor begins with the activation of olfactory receptors located in the olfactory epithelium. When an odorant binds to these receptors, it triggers a series of events that culminates in the transmission of signals to the olfactory bulb.

From the olfactory bulb, the information is relayed through the olfactory tract to the olfactory cortex, which is involved in the perception of smell and the processing of olfactory information. This direct pathway is crucial because it bypasses the thalamus, which is usually a relay center for sensory information. This characteristic underscores the uniqueness of the olfactory system in processing smells more rapidly and differently compared to other sensory modalities.

In summary, the pathway for smell is accurately described as moving from the olfactory bulb to the olfactory tract and then onto the olfactory cortex. This sequence is essential for the human ability to detect and perceive a wide variety of odors effectively.