Olfactory pathway

Medical neuroscience

1. Olfactory
pathway
Domina
Petric, MD

2. Introduction
•The olfactory mucosa contains
theolfactory receptor neuronsthat are
responsible for scent transduction.
•The transduction occurs in theolfactory
receptorslocated on cilia at the ends of
the olfactory receptor neurons.
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3. The olfactory epithelium
•Theolfactoryepithelium includes several
distinct cell types.
The most important of these is theolfactory
receptor neuron:
•a bipolar cell that gives rise to a smallin
diameter, unmyelinatedaxonat its basal
surface
•axon transmitsolfactoryinformation centrally
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4. The olfactory cilia
•At its apical surface, the receptor neuron
gives rise to a single process.
•The processexpands into a protrusion from
which several microvilli, olfactorycilia,
extend into a thick layer of mucus.
•Two other cell classesare also in the
olfactory epithelium:basal cells and
sustentacular(supporting) cells.
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5. The oflactory receptors
•Olfactory receptorsare protein
molecules attached to the olfactory
receptor neurons.
•There are about 1,000 kinds of olfactory
receptors.
•Allthe olfactory receptors are the same
on each olfactory receptor neuron.
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6. Passive vs. assisted pathway
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7. The passive pathway
Molecules reach the
olfactory mucosa via
inhaled air.
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8. The assisted pathway
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9. The electrical signal
The electrical signal is sent
via the axons of the olfactory
neurons to structures
calledglomerulion the left
and rightolfactory bulbs.
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10. http://archive.cnx.org
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11. The olfactory pathway
•Informationis conducted from the
olfactory bulbs by thelateral olfactory
tractto theprimary olfactory cortex.
•it goes to thethalamus(mediodorsal
nucleus)and on to theorbito-frontal
cortex.
•Here theconscious smell perception
occurs.
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12. Limbic system
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13. Literature
•http://www.ucalgary.ca
•http://archive.cnx.org
•https://www.ncbi.nlm.nih.gov/b
ooks/NBK10896/ (Neuroscience,
2nd edition)
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