Olfactory / Sense of Smell Flashcards
What is the Anatomy of the Olfactory receptors?
The nose contains 10 - 100 million receptors for Olfactory sense of smell contained in an area called “Olfactory Epithelium”.
There is 3 types of Olfactory receptors:
Olfactory receptor cells, Supporting cells & Basal cells.
What do the Olfactory Receptor cells consist of?
First order neurons of the Olfactory pathway.
Olfactory cells that are the cite of transduction.
Within the “Olfactory Cells” are Receptors that detect inhaled chemicals.
How do Olfactory Cells work?
Within the cells there is Receptors that detect inhaled chemicals called “Odorants”.
What are Oderants?
These are the chemicals detected by the Olfactory Cell’s receptors that produce a sense of smell.
What do Supporting cells of Olfactory Sense consist of?
Columnar Epithelial cells and mucus membrane lining of the nose.
What do Supporting cells of the olfactory sense provide?
They provide physical support, nourishment, electrical insulation for the olfactory receptors and Help detoxify chemicals that come in contact with the Olfactory Epithelium.
What do the Basal Cells of the Olfactory Sense consist of?
Stem cells between the bases of supporting cells.
They continually undergo cell division to produce new olfactory receptors which only live fo only a month or so before being replaced.
How often must the Stem cells of the Basal cells be replaced in the Olfactory Sense?
They live for only about a month or so before needing to be replaced.
They continually divide to produce new olfactory receptors.
What is Odor Threshold and Adaptation?
Only small amounts of chemicals need to be present for you to perceive the Odor / Pass the threshold.
Adaptation is rapid decreasing of sensitivity to odors.
How much do Olfactory receptors adapt after the first second of being present to the Olfactory receptors?
It adapts by about 50% and then very slowly after that.
What is the Olfactory pathway?
On each side of the nose is about 40 bundles of Axons of Olfactory receptor cells Extend through about 20 Olfactory foramina in Cribiform plate.
What are the Olfactory Nerves?
They are the Collective bundles of nerves from R & L form the Olfactory nn’s.
What are Olfactory Bulbs?
Olfactory nn’s terminate in the brain in paired masses of grey matter called Olfactory Bulbs.
What forms the Olfactory Tract?
Axons of the Olfactory Bulb neurons extend posteriorly and form the Olfactory Tract.
What projects into the Primary Olfactory Area?
Some of the Axons of the Olfactory tract project to The Primary Olfactory Area of the Cerebral Cortex.
