Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuroscience > The Chemical Senses > Flashcards

The Chemical Senses Flashcards

1
Q

What tastes are innately enjoyed and why?

A

→ Sweet and fatty

→ They provide energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is bitterness disliked?

A

→ Taste of bitterness is associated with poison

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 5 tastes?

A

→ Sweet
→ bitter

→ sour
→ salt
→ umami

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where are taste buds present other than the tongue?

A

→ Palate

→ Epiglottis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What two types of cell are inside a taste bud?

A

→ Basal cells

→ Taste cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are basal cells?

A

→ Juvenile taste cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are taste cells and what do they look like?

A

→ Mature taste cells which have microvilli that project towards the taste pore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What would be seen if you took a voltage recording of taste cells?

A

→ Different responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How are saltiness and sourness transduced?

A

→ Ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How are bitterness, sweetness and umami transduced?

A

→ GPCR via T1 and T2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe how saltiness is transduced

A

→ High Na+ concentration when eating salt
→ Na+ passes through Na+ selective channels down its concentration gradient

→ This depolarises the taste cell and activates voltage gated Ca2+ channels
→ Vesicular release of NT (5-HT) is elicited and gustatory afferents are activated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the ion component of sourness?

A

→ H+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe how sourness is transduced

A

→ H+ can pass through the same Na+ channels that mediate saltiness
→ H+ blocks K+ sensitive channels

→ Increased H+ and blocking K+ depolarise the cell and activate voltage gated Ca2+ channels
→ Vescicular release of neurotransmitters(5HT) is elicited and gustatory afferents are activated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe how bitterness is transduced

A

→ T2 receptors are Gq coupled
→ PLC converts PIP2 → DAG + IP3

→ IP3 activates a type of Na+ channel and releases Ca2+ from the endoplasmic reticulum
→ Depolarises the taste cell and activates voltage gated Ca2+ channels
→ Release of ATP is elicited and gustatory afferents are activated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What taste receptors is bitterness detected by?

A

→ T2 receptors

→ 25 types

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are T1/2 receptors coupled with?

A

→ Gq

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What receptor detects sweetness?

A

→ A dimer receptor formed of T1R2+T1R3

18
Q

How is sweetness transduced?

A

→ Same as bitterness

19
Q

Why do we not confuse bitter, sweet and umami tastes?

A

→ Taste cells either express bitter or sweet receptors not both
→ Bitter and sweet taste cells connect to different gustatory axons

20
Q

What receptor detects umami?

A

→ Dimer receptor formed of T1R1 + T1R3

21
Q

How is umami transduced?

A

→ Same as bitterness and sweetness

22
Q

What does CN VII transmit information from?

A

→ Anterior tongue

23
Q

What does CN IX transmit information from?

A

→ Posterior tongue

24
Q

What does CN X transmit information from and what kind of information?

A

→ Epiglottis

→ Temperature and texture

25
Q

What is the pathway to the gustatory cortex

A

→ Gustatory nucleus within the medulla
→ Transmitted to ventral posterior nucleus of the thalamus

→ projects to the gustatory cortex

26
Q

What are pheromones?

A

→ Signals for reproductive behaviours, marking territories, indicating aggression or submission

27
Q

What do we smell with?

A

→ Olfactory epithelium

28
Q

What is the olfactory epithelium?

A

→ Dendrites of olfactory cells that protrude from the olfactory bulbs through holes called the cribiform plate
→ they have cilia and are covered in a mucus layer

29
Q

What are olfactory receptor cells?

A

→ Site of transduction and are genuine neurons unlike taste receptor cells

30
Q

What are supporting cells?

A

→ They function like glia and help produce mucus

31
Q

Describe how odorant molecules activate the receptors

A

→ Odorant molecules bind to odorant receptor proteins on the cilia
→ Olfactory specific Golf G proteins are activated

→ Adenylyl cyclase activation increases cAMP formation
→ cAMP activated channels open allowing Na+ and Ca2+ influx
→ Ca2+ activated chloride channels open enabling Cl- efflux
→ Olfactory cells have a high concentration of Cl- ions so they diffuse out

32
Q

Describe the changes in action potential frequency from the nerve to the cilia

A

→ AP propagate continously along the olfactory axon
→ receptor potential propagates along dendrite and triggers AP within the soma

→ Odorants generate a slow receptor potential in the cilia

33
Q

Describe what central olfactory pathways are

A

→ Odor molecules bind to olfactory receptor proteins
→ These transmit to different cells in the olfactory bulbs

→ Olfactory cells expressing the same receptor proteins project to the same glomeruli
→ the glomeruli converge onto common pathways
→ transmitted to higher regions of the brain

34
Q

Where does the olfactory bulb project?

A

→ Frontal cortex - perception of what smell is
→ hypothalamus and amygdala give you emotional aspect of the smell such as a memory which is coupled to the hippocampus
→ hippocampus gives odour memory

35
Q

What do the other senses project through?

A

→ Thalamus

36
Q

What channels are used to detect low concentrations of salt?

A

→ Amiloride sensitive channels

→ insensitive to voltage and stay open

37
Q

What determines the specificity of sweetness or umami?

A

→ T1R subunit

38
Q

What are basal cells?

A

→ Immature olfactory receptor cells - source of new olfactory receptor cells

39
Q

Describe an example of population coding for olfaction

A

→ When presented with a citrus smell none of the receptor cells can individually distinguish it from other odours
→ the brain can distinguish the citrus smell through combination of responses from all 3 cells

40
Q

What is population coding?

A

the responses of a large number of broadly tuned neurons are used to specify the properties of a particular stimulus

41
Q

What are the different papillae on the tounge?

A

→Ridge-shaped (foliate)
→Pimple-shaped (vallate)
→Mushroom-shaped (fungiform)

Neuroscience (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions