Smell Flashcards
Where is the olfactory region?
The extreme superior region of nasal cavity (really high up in your nose!)
Olfactory epithelium
Contains 10 million olfactory neurons and lines the olfactory region
Olfactory bulb
The structure above the cribriform plate that contains secondary olfactory neurons.
Olfactory tracts
The pathway that connects the olfactory bulb to the cerebral cortex
How does smell work? 3 steps
1) Olfactory neurons are stimulated by an odorant
2) Olfactory neurons synapse with secondary olfactory neurons in the olfactory bulb
3) Olfactory tract sends olfaction to the cerebral cortex
What are odorants?
Airborn molecules that bind to chemoreceptors
How many smells can the average person detect?
4000
Why is olfaction adaptable?
When olfactory neurons are saturated, they no longer respond to olfactory stimulation
Olfactory vesicles
dendrites of olfactory neurons that extend to epithelial surface of nasal cavity
Olfactory hairs
Cilia on the olfactory vesicles
What is the chemical process of olfaction?
1) an odorant binds to a receptor
2) G proteins activate adenylate cyclase
3) adenylate cyclase causes ATP to catalyze into cAMP
4) cAMP opens ion channels
5) ions entering olfactory hair depolarize the neurons
Which nerve is the olfactory nerve?
Cranial Nerve I
How is olfaction different from the other special senses?
processing involves multiple areas of the brain instead of a dedicated area.
Primary area of the brain that processes olfaction
Central olfactory cortex area in the temporal and frontal lobes of the cerebrum
3 areas of the brain associated with the central olfactory cortex
1) piriform cortex
2) amygdala
3) orbitofrontal cortex
