PPT 3/4: Taste and Smell Flashcards Preview

Organ Systems III MTII Senses and Embr. Devel. > PPT 3/4: Taste and Smell > Flashcards

Flashcards in PPT 3/4: Taste and Smell Deck (21)
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Salt, Sweet, Sour, Bitter, or Unami?
A. Na+ channel
B. Uses IP3 2nd messenger
C. Uses cAMP 2nd messenger
D. H+/K+ channel

A. Salt
B. Bitter and unami
C. Sweet
D. Sour


What is meant by the term supertaster?

Heightened response to taste due to increased number of fungiform papillae


Papillae: Filiform, Fungiform, Circumvallate, or Foliate?
A. Shape of inverted V near back of tongue
B. Contain taste buds
C. For touch, temperature, and pain
D. Anterior part of tongue (pink dots)
E. In small trenches on sides of posterior tongue

A. Circumvallate
B. All except filiform
C. Filiform
D. Fungiform
E. Foliate


Where is the intestinal peptide GLP-1 produced?

GLP-1 and its receptor are produced and released from taste cells in response to food. GLP-1 usually associated with intestinal activity.


Central Taste Pathway Steps: Put in Order
1. OFC
2. Solitary nucleus in medulla
3. Insula
4. Ventral posterior medial nucleus of thalamus

2. Solitary nucleus in medulla
4. Ventral posterior medial nucleus of thalamus
3. Insula (Primary gustatory cortex)
1. Orbitofrontal cortex (Secondary gustatory cortex)


How does GLP-1 affect taste reception?

GLP-1 alters cell responsivity to taste (enhances sweet, decreases unami).


T or F: Taste Buds
A. Consist of 1-3 taste receptor cells
B. Each cell's microvilli project through taste pore
C. Receptor cells have receptors for only 1 type of taste
D. Each region of tongue has group of taste buds, each tuned to a specific taste

A. False. 50-100
B. True
C. False. Receptors for most tastes, but tuned mostly to 1
D. True


T or F: Taste Receptors
A. Taste stimuli interact w/ ion channels or membrane receptors
B. Taste neurons respond to only one type of taste.
C. Receptors for each taste type are distributed evenly
D. Taste stimuli trigger 2nd messengers

A. True
B. False. They respond to different types of taste stimuli
C. False. They are selectively expressed in subsets of cells
D. True


Central Taste Pathways: Which cranial nerve?
A. Anterior 2/3 of tongue
B. Palate and epiglottis
C. Posterior 1/3 of tongue

A. Facial CN VII
B. Vagus CN X
C. Glossopharyngeal CN IX


Four roles of Secondary Gustatory Complex?

1. Receive input from insula (primary gustatory complex).
2. Appreciation of flavor, food reward, control of feeding
3. Integration of taste, olfactory, visual cues of food
4. Decision to ingest or reject a food


How do TASTE stimuli activate receptor cells?

Interact w/ ion channels or membrane receptors that trigger 2nd messengers.
This leads to depolarization, Ca influx, transmitter release, and nerve firing


Amygdala, Hypothalamus, OFC, or Piriform?
A. Found on medial surface of temporal lobe
B. Integrates odor, taste, oral texture, visual
C. Primitive cortex with 3 layers

A. Piriform
C. Piriform


Amygdala, Hypothal., Hippocampus, Piriform, or OFC?
A. Piriform projects to this/these
B. Amygdala projects to this/these
C. Olfactory bulb projects to this/these

A. Amygdala, hippocampus, and OFC
B. Hypothalamus and OFC
C. Piriform


Describe how intranasal substances such as viruses and peptides are transported to the CNS.

Viruses can be taken up by olfactory neurons, transported along axons to the olfactory bulb, and can travel transynaptically to the limbic system.


T or F: Olfactory Receptor Cells
A. Cilia w. odorant receptors project into mucus layer
B. Mitral cells project through cribiform plate to insula
C. Axons innervate olfactory bulb mitral cells
D. Receptors have lifespan of 1-2 mos & can be replaced

A. True
B. False. Axons project through cribiform plate to olfactory bulb.
C. True
D. True. Replaced by basal stem cells.


Role of insula?

Primary gustatory cortex
Taste identification and intensity; discrimination


How do ODORANTS activate receptor cells?

Odorants activate Na+/Ca+ (IN) and Cl- ion (OUT) channels on receptor microvilli. Depolarization and AP generation.


Describe how odorants stimulate receptor adaptation.

Ca+ dependent and Ca+ independent pathways that inhibit receptors, close ion channels, and enhance outward pumping of ions.


Amygdala, Hypothalamus, OFC, or Piriform?
A. Subjective assessment (pleasantness), Valuation
B. Associative learning, emotion
C. Olfactory related autonomic & endocrine changes
D. Habituation

B. Amygdala and OFC. (Amygdala also has long term memory)
C. Hypothalamus
D. Piriform


T or F?
Neurons respond to odorant mixture but not components.



What is the result of habituation in the olfactory system? Why is this beneficial?

Habituation results in rapid reduction in cortical response to stimulation ( in addition to receptor adaptation).
Helps olfactory system detect new odorants against the background of existing odorants