SDL π¨βπ» Flashcards
Site of Olfactory receptors
- extreme superior region of nasal cavity (olfactory recess)
Number of Olfactory receptors
- Ten million olfactory neurons.
Life span of Olfactory receptors
- regenerate every 2 monthes
what regenerates Olfactory receptors?
- basal cell
what neurons have the most exposed nerve endings of any neurons?
The primary olfactory neurons, and they are constantly being re-placed
what is charachterestic Olfactory receptors?
- They are constantly being re-placed
Threshold of Olfactory receptors
- The threshold for the detection of odors is very low,
- So very few odorant molecules are required to trigger the response.
Specifity of Olfactory receptors
- Low specificity in the olfactory epithelium
- A given receptor may react to more than one type of odorant.
Characters of Methyl-mercaptan
- Has a nauseating odor similar to that of rotten cabbage
- Added to natural gas at a concentration of about 1 part per million
- A person can detect the odor of about 1/25 billionth of a milligram of the substance
Significance of Methyl-mercaptan
Awarness of natural gas leakage
Mechanism of stimulation of olfaction
- Odorant enter nasal cavity then dissolve in fluid of nose and bind to chemoreceptor of olfactory hair resulting in depolarization by unknown mechanism
what is the number of types of odors can be discriminated by olfactory receptor?
4000 types of odors, by unknown mechanism
what are the seven primary classes of odours?
- Camphoraceous
- Floral
- Ethereal
- PutridItβs very unlikely
- Musky
- Pepperminty
- Pungent
what is the only major sensation that doesnβt pass by the thalamus? and where does it pass?
- Olfaction
- Passes directly to the frontal cortex
First order neuron of Neural pathway Olfaction
Olfactory receptor = Bipolar cell
what part of ethmoid bone does the olfactory nerve pass by during its course?
Cribriform plate
2nd order neuron of Neural pathway Olfaction
Olfactory tract (Mitral cell & Tufted cell)
the olfctory bulb is considered a part of β¦β¦.
brain
What does the olfactory tract pass to?
Medial, lateral & Intermediate olfactory areas
Function of medial olfactory area
Visceral & Emotional response to odour β> limbic system & Hypothalamus
Function of lateral olfactory area
Conscious perception of smell
Function of intermediate olfactory area
Synapse with association neuron to modulate sensory information within olfactory bulb
Neural pathway olfaction
what is another name for taste?
Gustation