Term
What are the receptor cells for smell sensation? |
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Definition
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Term
Where are the olfactory sensory neurons located? |
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Definition
Within the olfactory epithelium |
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Term
Where do the olfactory sensory neurons project to__________? |
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Definition
To the olfactory bulb of the brain |
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Term
What are the 3 cell types of the olfactory epithelium? |
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Definition
1. Olfactory sensory neurons
2. supporting cells
3. basal stem cells |
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Term
Why does the supporting cells secrete mucus? |
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Definition
1. to bathe the odorant receptors
2. to provide the molecular and ionic environment for odor detection |
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Term
Odorant receptors are located on the |
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Definition
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Term
What is the function of the basal stem cells? |
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Definition
To make new olfactory sensory neurons |
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Term
The olfactory sensory neuron dendrite projects into the __________ |
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Definition
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Term
Where does the dendrite terminate at? |
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Definition
At a knob that has 10 - 20 cilia,
the cilia has the odorant receptors |
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Term
When an odor binds to its receptor on the cilia what happens? |
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Definition
1. Signals a cascade
2. Creates an action potential in the sensory axon |
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Term
How many axons project from each neuron to the olfactory bulb? |
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Definition
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Term
What must the axons of the neurons pass in order to enter the olfactory bulb? |
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Definition
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Term
How many different smells are there? |
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Definition
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Term
How many odorant receptors do we have? |
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Definition
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Term
All the receptors are coupled to a _____? |
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Definition
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Term
What happens when an odor binds to its receptor? |
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Definition
1. G-protein dissociates
2. alpha subunit activates the adenylate cylcase
3. cAMP is made
4. cAMP binds to cation channels
5. Cation channels open so Ca2+ moves inward
6. Action Potential occurs |
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Term
Olfactory receptor cells can project to different______________? |
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Definition
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Term
In the Olfactory glomeruli the olfactory sensory neurons axons synapse to _____________ |
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Definition
The dendrites of the mitral and tufted cells |
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Term
The axons of the mitral and tufted cells go into the ____________ |
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Definition
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Term
What connects glomerulus together? |
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Definition
Periglomerular cells
(they are inhibiting neurons) |
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Term
__________ synapses with the lateral dendrites of the mitral and tufted cells |
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Definition
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Term
How do the mitral and tufted cells excite the granule cells? |
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Definition
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Term
How do the granule cells inhibit the mitral and tufted cells? |
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Definition
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Term
What are the regions that the mitral and tufted cells terminate on? |
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Definition
1. Anterior olfactory nucleus
2. Olfactory tubercle
3. Piriform cortex
4. Amygdala
5. Entorhinal Cortex
6. Orbitofrontal cortex |
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Term
What kind of function does the Amygdala serve? |
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Definition
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Term
What function does the frontal or orbitofrontal cortex serve? |
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Definition
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Term
Other mammals and rodents have what organ in their olfactory epithelium? |
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Definition
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Term
Animals perceive odors as_________ |
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Definition
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Term
In other animals, besides humans, the olfactory sensory neurons project to where? |
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Definition
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Term
Where does the neurons go after the accessory olfactory bulb in other animals? |
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Definition
primarily to the amygdala and hypothalamus |
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Term
The vomernasal organ has ____________ that differ from the rest that are on the olfactory epithelium |
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Definition
100 G-coupled odorant receptors |
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Term
What two things are shown to be closely related? |
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Definition
Smell and sexual function |
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Term
What 5 sensations can we mainly smell? |
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Definition
1. Floral
2. Musky
3. Pepperminty
4. Pungent
5. Putrid |
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Term
Why does the smell seem to cease when exposed to it continously? |
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Definition
We have adapted to it or have become desentisized |
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Term
Adaptation is mediated by ______ ions acting via calmodulin on ___________ ion channels. |
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Definition
1. Ca2+
2. cyclic nucleotide gated (CNG) |
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Term
True/False: Only a small amount of the agent is needed to elicit a smell sensation. |
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Definition
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Term
Methylmercaptan (garlic) has a _____ threshold, only needing __________ in a mL air |
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Definition
1. Low
2. 1/25 trillionth of a gram |
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Term
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Definition
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Term
Hyposmia or Hypesthesia is when you have deminished ____________ |
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Definition
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Term
Hyperosmia is when you have _______________ |
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Definition
Enchanced olfactory sensitivity
(heightned sense of smell) |
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Term
What can lead to a decrease in smell? |
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Definition
1. nasal congestion
2. fractures of the cruciform plate
3. tumors
4. infections
5. Alzheimers
6. Aging
7. Damage to the olfactory nerve |
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Term
What % of people over the age of 80 have a decreased ability to identify smells? |
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Definition
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Term
Dysosmia is when your sense of smell is ___________ |
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Definition
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Term
Dysosmia can be caused by |
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Definition
1. sinus infection
2. partial damage to the olfactory nerve
3. poor dental hygiene |
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