Ch 14 The Chemical Senses testbank ?s

Question 1

1. Which structure separates the olfactory epithelium from the olfactory bulbs?
   a. Olfactory tract
   b. Odorants
   c. Pyriform cortex
   d. Cribiform plate
   e. Sphenoid bone

Answer 1

Answer: d
Textbook Reference: Organization of the Olfactory System
Bloom’s Level: 1. Remembering

Question 2

2. The olfactory bulb does not project to the
   a. thalamus.
   b. amygdala.
   c. entorhinal cortex.
   d. olfactory tubercle.
   e. pyriform cortex.

Answer 2

Answer: a
Textbook Reference: Organization of the Olfactory System
Bloom’s Level: 2. Understanding

Question 3

3. Which brain region is dedicated solely to olfaction perception?
   a. Amygdala
   b. Pyriform cortex
   c. Orbitofrontal cortex
   d. Hippocampal formation
   e. Hypothalamus

Answer 3

Answer: b
Textbook Reference: Organization of the Olfactory System
Bloom’s Level: 1. Remembering

Question 4

4. A room is filled with the scents of lavender and roses during a woman’s fMRI. Where
   would a researcher expect to see increased brain activity?
   a. Orbitofrontal cortex
   b. Cingulate cortex
   c. Insular cortex
   d. Both orbitofrontal and cingulate cortex
   e. Both cingulate and insular cortex

Answer 4

Answer: d
Textbook Reference: Olfactory Perception in Humans
Bloom’s Level: 3. Applying

Question 5

5. In which disease or disorder is olfaction dysfunction or anosmia part of the diagnostic
   criteria?
   a. Eating disorders only
   b. Schizophrenia only
   c. Parkinson’s disease only
   d. Eating disorders and schizophrenia only
   e. Eating disorders, schizophrenia, Parkinson’s disease, and Alzheimer’s disease

Answer 5

Answer: e
Textbook Reference: Assessing Olfactory Function in the Laboratory or Clinic
Bloom’s Level: 2. Understanding

Question 6

6. The mucus layer and the epithelium, with neural and supporting cells is(are) called
   a. Bowman’s glands.
   b. basal cells.
   c. nasal mucosa.
   d. sustentacular.
   e. olfactory receptor neurons.

Answer 6

Answer: c
Textbook Reference: Olfactory Epithelium and Olfactory Receptor Neurons
Bloom’s Level: 1. Remembering

Question 7

7. A scientist creates a knockout rat that has nonfunctional Bowman’s glands. Which
   functional effect would this most likely have on the rat?
   a. Inability to detect odorants
   b. Increased ability to maintain temperature and moisture of inhaled air
   c. Inability to generate olfactory receptor neurons continuously
   d. Increased susceptibility to infection
   e. Decreased surface area for odorants to bind to olfactory receptor neurons

Answer 7

Answer: d
Textbook Reference: Olfactory Epithelium and Olfactory Receptor Neurons
Bloom’s Level: 3. Applying

Question 8

8. Which cell types are not involved with proper generation of olfactory receptor neurons
   throughout an animal’s lifetime?
   a. Extant neurons
   b. Sustentacular cells
   c. Neural stem cells
   d. Basal cells
   e. Olfactory ensheathing cells

Answer 8

Answer: b
Textbook Reference: Olfactory Epithelium and Olfactory Receptor Neurons
Bloom’s Level: 2. Understanding

Question 9

9. Which conclusion can be drawn regarding the high number of olfactory pseudogenes
   in humans?
   a. The number of odorants in the environment has decreased over evolutionary time.
   b. Human olfaction detects as many odorants as other mammals but requires fewer
   expressed genes.
   c. The number of odorant receptor genes is irrelevant for determining an organism’s
   olfaction ability.
   d. Olfaction ability in humans is increasing, and we will soon be able to detect more
   odors than other mammals can.
   e. Reliance on olfaction has decreased throughout human evolution.

Answer 9

Answer: e
Textbook Reference: Odor Transduction and Odorant Receptor Proteins
Bloom’s Level: 4. Analyzing

Question 10

10. A scientist creates a mouse model with dysfunctional cyclic nucleotide-gated
    channels. Which of the following would not occur in this model?
    a. Dissociation of α subunit from G olf
    b. Influx of calcium
    c. Increase in cAMP
    d. Activation of adenylyl cyclase III
    e. Odorant binding to odor receptor proteins

Answer 10

Answer: b
Textbook Reference: Molecular and Physiological Mechanisms of Olfactory Odor
Transduction
Bloom’s Level: 3. Applying

Question 11

11. Which protein is important for modifying receptor sensitivity in olfaction?
    a. β-arrestin
    b. Calcium/calmodulin kinase II
    c. Phosphodiesterase
    d. Adenylyl cyclase III
    e. G olf

Answer 11

Answer: a
Textbook Reference: Molecular and Physiological Mechanisms of Olfactory Odor
Transduction
Bloom’s Level: 1. Remembering

Question 12

12. Which cell type does not synapse within glomeruli?
    a. Mitral
    b. Tufted
    c. Periglomerular
    d. Granule
    e. Receptor

Answer 12

Answer: d
Textbook Reference: The Olfactory Bulb
Bloom’s Level: 2. Understanding

Question 13

13. Exposure to a single odor activates _______ glomeruli, while exposure to a complex
    odor (150 compounds) activates _______ glomeruli.
    a. a few; many
    b. a few; all
    c. a few; a few
    d. many; many
    e. many; all

Answer 13

Answer: c
Textbook Reference: The Olfactory Bulb
Bloom’s Level: 2. Understanding

Question 14

14. A patient sustains a head injury resulting in damage of some glomeruli. Which effect
    would most likely result from this damage?
    a. Inability to detect certain smells
    b. Decreased sensitivity to smells but all smells would be detectable
    c. Proliferation of periglomerular cells
    d. Inability to detect all smells
    e. No effect; glomeruli would regenerate from stem cells

Answer 14

Answer: a
Textbook Reference: The Olfactory Bulb
Bloom’s Level: 3. Applying

Question 15

15. Which type cell type primarily forms the lateral olfactory tract, which projects to
    many areas in the brain?
    a. Olfactory receptor neuron
    b. Granule
    c. Tufted
    d. Mitral
    e. Periglomerular

Answer 15

Answer: d
Textbook Reference: Pyriform Cortical Processing of Information Relayed from the
Olfactory Bulb
Bloom’s Level: 1. Remembering

Question 16

16. Most projections from the lateral olfactory tract are _______, and they _______
    activate the pyriform cortex, _______ the activation of glomeruli to different odors.
    a. ipsilateral; selectively; like
    b. ipsilateral; broadly; unlike
    c. contralateral; selectively; unlike
    d. contralateral; broadly; unlike
    e. ipsilateral; broadly; like

Answer 16

Answer: b
Textbook Reference: Pyriform Cortical Processing of Information Relayed from the
Olfactory Bulb
Bloom’s Level: 2. Understanding

Question 17

17. Projections from the pyriform cortex to other brain regions allow olfaction to
    influence which other behavior(s) and/or function(s)?
    a. Sexual only
    b. Appetitive only
    c. Memory, sexual, and appetitive only
    d. Sexual and appetitive, but not visceral
    e. Sexual, appetitive, memory, and visceral

Answer 17

Answer: e
Textbook Reference: Pyriform Cortical Processing of Information Relayed from the
Olfactory Bulb
Bloom’s Level: 2. Understanding

Question 18

18. A _______ would be least likely to show a change in behavior in response to species-
    specific pheromones.
    a. human
    b. tiger
    c. rat
    d. badger
    e. wolf

Answer 18

Answer: a
Textbook Reference: The Vomeronasal System: Predators, Prey, and Mates
Bloom’s Level: 3. Applying

Question 19

19. Neurons from the _______ project to the hypothalamus and the _______.
    a. accessory olfactory bulb; pyriform cortex
    b. accessory olfactory bulb; amygdala
    c. accessory olfactory bulb; cerebellum
    d. olfactory bulb; amygdala
    e. olfactory bulb; pyriform cortex

Answer 19

Answer: b
Textbook Reference: The Vomeronasal System: Predators, Prey, and Mates
Bloom’s Level: 2. Understanding

Question 20

20. A scientist studying the vomeronasal system creates a V2R knockout rat.
    Measurement of which variable would best evaluate the behavior of the knockout animal
    compared to controls?
    a. Time elapsed before mating between a male and female rat
    b. Time a mother spends with rat pups
    c. Number of aggressive bites between two male rats
    d. Distance traveled away from cat spray (kairomones)
    e. Time spent self-grooming while awake

Answer 20

Answer: d
Textbook Reference: The Vomeronasal System: Molecular Mechanisms of Sensory
Transduction
Bloom’s Level: 4. Analyzing

Question 21

21. Taste cells are not present in which part of the mouth?
    a. Tongue
    b. Pharynx
    c. Gums
    d. Upper esophagus
    e. Soft palate

Answer 21

Answer: c
Textbook Reference: Organization of the Taste System
Bloom’s Level: 1. Remembering

Question 22

22. _______ projections are topographically represented along the rostral–caudal axis in
    the _______.
    a. Cranial nerve; insular taste cortex
    b. Nucleus of the solitary tract; insular taste cortex
    c. Cranial nerve; gustatory nucleus
    d. Nucleus of the solitary tract; frontal taste cortex
    e. Cranial nerve; frontal taste cortex

Answer 22

Answer: c
Textbook Reference: Organization of the Taste System
Bloom’s Level: 2. Understanding

Question 23

23. _______ papilla, located posteriorly on the tongue, would respond most strongly to a
    _______ tastant.
    a. Foliate; umami
    b. Fungiform; salt
    c. Circumvallate; sweet
    d. Foliate; sour
    e. Circumvallate; bitter

Answer 23

Answer: e
Textbook Reference: Taste Perception in Humans
Bloom’s Level: 2. Understanding

Question 24

24. A scientist creates a TRP channel knockout mouse model for all TRP channels. These
    mice would not be expected to respond to which of the following tastants in their
    drinking water?
    a. Sweet, bitter, umami, sour
    b. Sweet, salty
    c. Salty, bitter
    d. Umami, sour, salty
    e. Umami, bitter, sour, salty

Answer 24

Answer: a
Textbook Reference: Taste Receptor Proteins and Transduction
Bloom’s Level: 4. Analyzing

Question 25

25. The T2R gene specifically codes for which taste?
    a. Sweet
    b. Sour
    c. Bitter
    d. Salty
    e. Umami

Answer 25

Answer: c
Textbook Reference: Taste Receptor Proteins and Transduction
Bloom’s Level: 1. Remembering

Question 26

26. A decrease in extracellular H + would decrease the ability to detect which taste?
    a. Sweet
    b. Sour
    c. Bitter
    d. Salty
    e. Umami

Answer 26

Answer: b
Textbook Reference: Taste Receptor Proteins and Transduction
Bloom’s Level: 3. Applying

Question 27

27. The G-protein gustducin is in involved in which of the following taste sensations?
    a. Sweet
    b. Sour
    c. Bitter
    d. Salty
    e. Umami

Answer 27

Answer: c
Textbook Reference: Taste Receptor Proteins and Transduction
Bloom’s Level: 2. Understanding

Question 28

28. Which evidence supports labeled line coding in the taste system?
    a. Increasing concentrations of tastants can overcome a genetic mutation that results in a
    deficiency of taste receptors.
    b. The same behavioral responses are observed in response to all tastants when specific
    taste receptors are inactivated.
    c. No change in cranial nerve activity is observed when specific taste receptors are
    inactivated.
    d. Mice re-expressing PLCβ2 in T2-expressing taste cells in a PLCβ2 mutant mouse are
    able to respond to bitter tastes.
    e. Receptor proteins re-expressing are expressed broadly in taste cells and not in subsets.

Answer 28

Answer: d
Textbook Reference: Neural Coding in the Taste System
Bloom’s Level: 4. Analyzing

Question 29

29. What would be the expected behavior of a TRPM 5 –/– knockout mouse compared to a
    wild type mouse?
    a. Increased drinking of water with glucose
    b. Similar drinking of water with glutamate
    c. Increased drinking of water with quinine
    d. Similar drinking of water with sucrose
    e. Decreased drinking of water with atropine

Answer 29

Answer: c
Textbook Reference: Neural Coding in the Taste System
Bloom’s Level: 4. Analyzing

Question 30

1. What features of the olfactory system make it highly sensitive to low concentrations of
   odorants?

Answer 30

Answer: Low concentrations of odorants are detectable due to the high degree of
convergence in the olfactory system. Many olfactory axons (25,000 in the mouse) that
almost exclusively express a single odorant receptor gene project to one glomerulus. This
glomerulus only synapses with a few (25 in the mouse) mitral cells. This convergence
allows for amplification of olfactory receptor neuron signals.
Textbook Reference: The Olfactory Bulb
Bloom’s Level: 2. Understanding

Question 31

2. How does olfactory information reach the brain region(s) that perceive(s) and
   interpret(s) odors?

Answer 31

Answer: Mitral cells in the olfactory bulb project to the pyriform cortex, which is the
primary olfactory cortex, via the lateral olfactory tract.
Textbook Reference: Pyriform Cortical Processing of Information Relayed from the
Olfactory Bulb
Bloom’s Level: 2. Understanding

Question 32

3. What is the difference between pheromones and kairomones?

Answer 32

Answer: Pheromones are stimuli that mediate behaviors such as mating and social
behavior among members of the same species. Kairomones are stimuli that modulate
behavior between different species, such as predator and prey.
Textbook Reference: The Vomeronasal System: Predators, Prey, and Mates
Bloom’s Level: 2. Understanding

Question 33

4. Describe the steps in sensory transduction in olfactory neurons.

Answer 33

Answer: An odorant enters the nasal cavity and binds to an odor receptor protein located
on the olfactory cilia. This triggers G olf to dissociate its α subunit to activate adenylyl
cyclase III (ACIII). This increases cAMP, which opens cyclic nucleotide-gated channels
to permit an influx of cyclic Na + and Ca 2+ for depolarization. When this depolarization
reaches the axon hillock, action potentials are generated. This signal travels to a
glomerulus where it synapses on mitral cells. These mitral cells then project to the
pyriform cortex for processing.
Textbook Reference: The Vomeronasal System: Molecular Mechanisms of Sensory
Transduction
Bloom’s Level: 3. Applying

Question 34

5. What are considered to be the primary taste categories?

Answer 34

Answer: The primary taste categories are salty, sour, sweet, bitter, and umami.
Textbook Reference: Taste Perception in Humans
Bloom’s Level: 1. Remembering

Question 35

6. List some differences between olfaction and taste in central processing.

Answer 35

Answer: The olfactory system projects to its primary cortex before projecting to the
thalamus, unlike other senses. Olfaction activation in the pyriform cortex is widespread,
whereas each individual taste is distinctly represented in its own domain in the cerebral
cortex.
Textbook Reference: Taste Perception in Humans
Bloom’s Level: 3. Applying

Question 36

7. Compare the taste receptors for sour and salty with those for sweet, bitter, and umami.

Answer 36

Answer: Sour and salty use ion channels, the amiloride-sensitive Na + channel, and H + -
permeant nonselective channel, respectively. Sweet, bitter, and umami all use G-protein
coupled receptors. Sweet uses a T1R2 and T1R3 heterodimer, whereas umami uses a
T1R1 and T1R3 heterodimer. Bitter uses only a T2R receptor for transduction.
Textbook Reference: Taste Receptor Proteins and Transduction
Bloom’s Level: 3. Applying

Question 37

8. How does taste information reach the neocortex? What part(s) of the cortex receive(s)
   input from the taste pathway?

Answer 37

Answer: Taste information from taste cells is transmitted to the nucleus of the solitary
tract via cranial nerves VII, IX, and X. This information is then relayed to the ventral
posterior medial nucleus of the thalamus and then projected to the insular and frontal
taste cortices.
Textbook Reference: Taste Receptor Proteins and Transduction
Bloom’s Level: 2. Understanding

Question 38

9. Are individual odors recognized by a labeled line strategy or by computing the activity
   from ensembles of neurons? Which system is involved in recognition of tastes?

Answer 38

Answer: Individual odors are recognized by computing the activity from ensembles of
neurons, whereas tastes are recognized by labeled line coding.
Textbook Reference: Neural Coding in the Taste System
Bloom’s Level: 2. Understanding