Sense of Smell Flashcards
What is the organ of smell?
The olfactory epithelium
Where is the olfactory epithelium located?
The olfactory epithelium covers the **superior nasal concha **
describe olfactory receptor cells
olfactory receptors cells are bipolar neurons with radiating olfactory cilia
What surrounds and cushions olfactory receptors?
Olfactory receptors are surrounded and cusioned by supporting cells which secrete mucus
where are basal cells located?
Basal cells lie at the base of the epithilium
How do the basal cells contribute to the olfactory epithelium?
Basal cells are the source of mitotic stem cell replacement of olfactory receptor cells
How often does mitotic stem cell replacement of olfactory receptors occur?
Every 30-60 days
How does the triggering of smell occur?
Dissolved odorants bind to receptor proteins in the olfactory cilia membranes, activating a second messenger system and ultimately triggering an AP
How man odors can humans distinguish?
10,000+ odors can be identified
(~1000 odor genes identified)
Describe the Olfactory Pathway
bundles of axons of olfactory receptor cells project upward through the olfactory foramina of the cribriform plate to synapse with the mitral cells of the olbactory bulb
What do Mitral Cells do?
Mitral cells amplify, refine and relay simultaneous impules via the olfactory tract to the:
-Olfactory cortex via the thalamus and
**- Pre-frontal cortex **
Where is the uncus located?
deep in the temporal lobe of the Olfactory cortex
where are smells interpreted?
In the pre-frontal cortex
and
the uncus within the olfactory cortex
How do the hypothalamus and amygdala (limbic system)
contribute to the olfactory process?
The hypothalamus and amygdala elicit emotional responses to smell
Smells that are associated with danger stimulate what response?
The sympathetic fight or flight response (genetic, not learned)
