Smell Flashcards
1
Q
What is the olfactory system?
A
- specialized for identifying specific molecules called odorants
2
Q
What are odorant molecules?
A
- volatile substances (easily sucked up in air or stay in air a bit)
- have a molecular weight in range of approximately 15 to 300
- most are lipid soluble and of organic origin, however many substances that meet these criteria have no odor
3
Q
What receptor proteins transduce odorants into a change in membrane potential?
A
- metabotropic g protein-coupled receptors
- humans express ~400 different types of odorant receptors
- each one is sensitive to a specific molecule
4
Q
What is the olfactory epithelium?
A
- the tissue of the nasal sinus that sits underneath the skull (the cribriform plate)
- contains olfactory receptors cells
- each cell expresses only one type of olfactory receptor protein
5
Q
Where do olfactory receptor cells synapse?
A
- in glomeruli in the olfactory bulb
6
Q
What is glomerulus?
A
- processes information from just one type of olfactory receptor cell (expressing a particular type of olfactory receptor protein)
- each glomerulus processes a distinct odor
7
Q
What is the pathway of olfactory information?
A
- olfactory receptors cells in the olfactory epithelium synapse in glomeruli in the olfactory bulb
- sends axons into brain
- info goes directly to primary olfactory cortex in temporal lobe and the amygdala (does not relay in thalamus)
8
Q
What smells are good and bad?
A
- odors are largely not hard wired to be innately good or bad
- whether we like or dislike an odor is related to learned associations
9
Q
How many odorants can humans recognize?
A
- up to ten thousand different odorants
