iClicker Module 5 & 6 Flashcards
What is the difference between taste and flavor?
Flavor involves both the gustatory and olfactory system
What structure actually transducer tastants (e.g. salt) into a neural signal?
Taste receptor
Which type of papillae has no taste function?
Filiform papillae
Which type of papillae is located on the side of the tongue?
Foliate papillae
The density of these papillae differ in super tasters?
Fungiform papillae
What is really unusual about type I and type II taste bud cells (as compared to other sensory neurons)?
Lack synapses
Which type of taste bud cells does synapse with gustatory afferents?
Type III cells
Which type of taste bud cells detect salts?
Type I cells
Which taste bud cells detect Unami?
Type II cells
Which of the following is a function of taste receptors?
Helps remove harmful chemicals from the airways
Slows the absorption of potential toxins in the stomach
Detect salt or sour tastants
Contribute to flavor
Potassium chloride can be used as a salt substitute but too much of it can cause a bitter metallic taste. Which ion is responsible for the salty taste?
K+ (Potassium)
Have you ever gone to a restaurant and thought the food was too salty, while another people seem to be eating it happily? What is the reason?
Your sensitivity to salty food can change depending on your diet
Which one of the following solutions would taste the sourest?
Solution A (pH 2)
Solution B (pH 4)
Solution C (pH 6)
SOlution D
Solution E
Solution A
How does the acidity of the solution relate to its perceived sourness?
More H+ ions will enter the tastebud cell when exposed to stronger acid
Why is it important top detect bitter compounds?
Bitter taste can signal the ingestion of poisons
How does taste bud cell sense bitter compounds?
Bitter compounds bind to a receptor, triggering a secondary message cascade increasing calcium
Why do we love the taste of High Fructose Corn Syrup in our foods?
Fructose is sweeter than glucose
How does a taste bud cell sense sweet compounds?
Glucose bind to a receptor, triggering a secondary messenger cascade increasing calcium
I love Chinese food. Should be especially worried about my intake of MSG?
No, not really
How does a taste bud cell sense MSG?
MSG bind to a receptor, triggering a secondary messenger cascade increasing calcium
How does a taste bud cell sense spicy food?
Taste bud cells don’t sense spicy foods
(part of nociceptors)
What to do if you eat something super spicy?
-Wait for the burning to stop (when your tongue becomes desensitized and the rest of it will be easier to eat)
-Drink milk/ eat chocolate (the fat helps break down the bounds between the capsaicin and the receptor)
-Sugar (granulated sugar and honey will reduce the heat; the sugar absorbs the spicy oil and will provide a different taste)
-Eat bread (soak up the oil that remain in your mouth
Which cranial nerve(s) carries information about tastings?
Cranial Nerve VII (Facial)
Cranial Nerve IX (Glossopharyngeal)
Cranial Nerve X (vagus)
Which brain area is thought to account for the perception of sweet?
Insular Cortex
Wavelengths of light is to color as _ are to _.
-Odorants
-Odors
Colors are different wavelengths of light
Components of an odor are made up of single chemicals
Do all chemicals have a ‘smell’ to humans?
No
(ex: CO2; carbon monoxide)
Out for his daily walk, a dog stops and smells a tree that is a popular spot for other dogs to pee. After 30 minutes, he stops and smells the same tree, assuming no other dogs peed on the tree. Does it smell exactly the same?
No
-changing, the chemical signal is changing all the time
-interacting with oxygen and other chemicals
-some evaporate, some combine, etc.
In what ways are olfactory stimuli different from auditory stimuli?
Olfactory stimuli can be detected for longer periods of time than auditory stimuli
What are the functions of your ‘nose’?
-detect airborne chemicals
-respiration
-humidification of inhaled air
-filtration of dust
Where is the olfactory epithelium located?
Turbinates in the nose
Most mammals are capable of regenerating olfactory sensory neurons to some degree. What cell type is responsible for this feat?
Basal cells
What is a glomerulus?
A cluster of nerve endings or axons
If the relationship between olfactory receptors and glomeruli were the same in mice and humans (it’s not). How many glomeruli would you expect humans (~400 olfactory receptors) to have?
Hint: what is the ratio of receptors to glomeruli in the mouse…
800
(we actually have 5500)
Phenylethylamine (C6H5CH2CH2NH2) smells like cat pee. What does phenylethanol (C6H5CH2CH2OH) smell like?
Roses
-Challenge in associating chemical structure
-Although similar, bind to different receptors and differ in perception
WHAT IS THE SHAPE PATTERN THEORY?
The extent of activation for
What is the theory of Primacy?
The earliest responding glomeruli encode odor identity
Why is olfaction important to your daily life?
Detect rotton/spoiled food
Provides flavor to your food
Allows you to avoid noxious chemicals
Plays a role in social/romantic/paternal attachments
Which of the following cells in targeted by Coronavirus?
Supporting cells
Why would the loss of the supporting cells cause the loss of smell?
Supporting cells provide metabolic and physical support for sensory neurons
Why does food usually taste like it smells?
The same odorants are stimulating the same receptors in your olfactory system (orthonasal vs retronasal)
Why do you cry when you smell onions?
Tears (and snot) are defense mechanisms to remove excess chemicals from your eyes and nose
Why do some of your classmates (in other classes) were a lot of perfume or cologne?
They have an olfactory disorder
Receptor adaptation
Cognitive habituation
Which of the following would be an example of cognitive habituation to olfactory stimuli?
I wear perfume/cologne all the time but I think they have changed the manufacturer because I can hardly smell it
How come during a second immediate sniff of an odorant, is it perceived to be less intense?
Receptor Adaptation
Which of the following cell types is thought to be responsible for transducing salt intake?
Type I
Statements about the gustatory system is incorrect?
In addition to the tongue, test receptors are also located in the stomach
Taste receptors only last a few days (constant renewal)
Taste receptors are involved in energy and glucose homeostasis
Taste receptors…
Which of the following cell types is thought to contribute to the maintenance of the taste cell?
Type I
Which of the following statements is true about fungiform papillae?
They are located in the t
Which of the following cell types is thought to be responsible for transducing umami?
Type II
Which of the following cell types releases serotonin to stimulate gustatory afferents?
Type III
Which of the following cell types expresses GCPRs?
Type II
This brain region is primarily responsible for the perception of salty?
Insular cortex
What are the tastants?
Umami, bitter, sweet, and salty
What are statements about sour transduction?
Occurs in type III cells
The more H+ ions the sourer the substance is perceived to be
H+ ions can enter via a selective ion channel
Which of the following gustatory cell types have true synapses?
Type III
How does a taste bud cell sense sweet compounds?
Sweet compounds bind to a receptor, triggering a secondary messenger cascade increasing calcium
How does a taste bud cell sense spicy food?
Taste bud cells don’t sense spicy foods
Which of the following statements regarding olfactory sensory neurons are incorrect?
They are located in the olfactory epithelium
Send their axons to the thalamus
At least in mice, each sensory neuron represents only one olfactory receptor
They are a neuron and have both a dendrite and an axon
Olfactory receptors are expressed in the cilia at the end of the dendrite
Send their axons to the thalamus
If you are are able to smell an odorant but is perceptually incorrect (i.e. banana smells like a dog) which type of olfactory disorder are you suffering from?
Parosmia
Everything smells the same… but you are less sensitive to these odors than before you had COVID. Which type of olfactory disorder are you suffering from?
Hyposmia
Which of the following cell types is not located in the olfactory epithelium?
Granule cells
Which of the following stimuli is not transduced by a GCPR?
Sour
What are 2 main inhibitory cell types in the olfactory epithelium/bulb?
Granule and Juxtaglomerular cells
What are 2 cell types that send their axons to the olfactory cortex?
Mitral and tufted cells
In the mouse, what is the ratio of receptors to glomeruli?
1:2
Which of the following statements about the olfactory system is incorrect?
A- At least in the mouse, sensory neurons that express the same receptor converge to form glomeruli
B- Glomeruli are located in the olfactory bulb
C- Mitral and tufted cells send their axons to the thalamus
D- The olfactory cortex consists of multiple brain regions a single odor can activate more than one olfactory receptor
Mitral and tufted cells send their axons to the thalamus
no thalamus
What are cell bodies of olfactory sensory neurons located?
Olfactory epithelium
Which of the following would be an example of cognitive habituation to olfactory stimuli?
A- I have lost my sense of smell (i.e. anosmic)
B- My friend says my dorm room smells weird, but I don’t smell anything
C- Food smells the same as it “tastes”
D- I can’t remember what that odor smells like
E- The second sniff of an odor smells less intense
My friend says my dorm room smells weird, but I don’t smell anything
Which of the following would be an example of receptor adaptation to olfactory stimuli?
A- I have lost my sense of smell (i.e. anosmic)
B- My friend says my dorm room smells weird, but I don’t smell anything
C- Food smells the same as it “tastes”
D- I can’t remember what that odor smells like
E- The second sniff of an odor smells less intense
The second sniff of an odor smells less intense
