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CHEMICAL SENSES
I. TRUE or FALSE. Circle the appropriate letter.
T F 1. Gustatory receptors are neurons.
T F 2. The vagus nerve conveys gustatory signals originating from the oropharynx
and upper esophogus.
T F 3. The thalamic terminations of the ascending taste pathways lie in the ventral
nuclear group, near the termination of ascending trigeminothalamic fibers.
T F 4. All primary gustatory afferents synapse in the nucleus of the solitary tract.
T F 5. Cortical neurons responsive to gustatory stimuli can be found near the tongue
area of the primary somatic sensory cortex and in the insula.
T F 6. Axons of the olfactory nerve arise from receptor cells in the olfactory mucosa.
T F 7. As in the visual and auditory modalities, olfactory signals must synapse in the
thalamus before reaching the cerebral cortex.
T F 8. The cortex of the medial temporal lobe that overlies the amygdala is a major
target of the olfactory tract.
T F 9. A patient who complains that food suddenly tastes bland may actually have
damage to the olfactory pathways.
T F 10. Like other neurons, olfactory receptors are never generated in adulthood.
T F 11. Individual gustatory receptor cells respond in association with more than one
of the primary gustatory qualities (sweet, salty, sour, bitter).
T F 12. The nucleus of the solitary tract contains secondary sensory neurons for both
taste and viscerosensory pathways.
II. MULTIPLE CHOICE. Circle every correct answer. There may be more than one
correct answer per question.
1. Taste signals from the anterior two-thirds of the tongue reach the brain after traveling
in
a.
b.
c.
d.
e.
the 7th cranial nerve
the solitary tract
the hypoglossal nerve
the facial (intermediate) nerve
the glossopharyngeal nerve
2. The gustatory sensations of "sharp," "spicy" and "piquant" most likely reflect afferent
activity in
a.
b.
c.
d.
e.
cranial nerve V
cranial nerve VII
cranial nerve IX
cranial nerve X
cranial nerve XII
3. Gustatory receptor cells
a.
b.
c.
d.
e.
are neurons
disappear if the axons innervating them are cut
are replaced about every ten days
are grouped together in taste buds
bear microvilli basally, at their point of contact with nerve fibers innervating
them
4. An axon innervating a taste bud on the posterior third of the tongue
a.
b.
c.
d.
e.
has its cell body in the facial nucleus of the brainstem
has its cell body in a cranial-nerve ganglion
enters the brainstem with the glossopharyngeal nerve
probably innervates one of the circumvallate papillae
synapses centrally in the nucleus of the solitary tract
5. Transduction in the olfactory system occurs
a. after odorant molecules pass through perforations in the skull to reach the
olfactory bulb
b. after odorant molecules are dissolved in the mucous layer of the olfactory
neuroepithelium
c. through interactions between odorant molecules and receptor molecule on the
cilia and microvilli of olfactory receptor cells
d. in non-neural receptor cells that do not generate action potentials
e. in the primary olfactory cortex
6. Seizures preceded by the sensation of an unpleasant odor usually originate from the
vicinity of
a.
b.
c.
d.
e.
the uncus
the amygdala
the olfactory mucosa
the cingulate gyrus
the nucleus of the solitary tract
7. The olfactory nerve (cranial nerve I) contains the axons of
a.
b.
c.
d.
e.
sustentacular (supporting) cells of the olfactory epithelium
receptor cells of the olfactory epithelium
tufted cells of the olfactory bulb
mitral cells of the olfactory bulb
granule cells of the olfactory bulb
8. Which of the following constitute major output targets of the olfactory bulb?
a.
b.
c.
d.
e.
phylogenetically old, simple parts of the cerebral cortex
the putamen
elements of the limbic system
the representation of the nose on the postcentral gyrus
the amygdala
9. Which of the following structures or neural elements can be found within the olfactory
bulb?
a.
b.
c.
d.
e.
cilia of olfactory receptor cells
axon terminals of olfactory receptor cells
glomeruli
mitral cells
inhibitory interneurons
10. Which of the following cell types are second order neurons in the olfactory system?
a.
b.
c.
d.
e.
bipolar neurons of the olfactory epithelium
cells in the nucleus of the solitary tract
neurons of the amygdaloid complex
mitral cells of the olfactory bulb
neurons of the olfactory cortex
CHEMICAL SENSES
I. True or False
1.
2.
3.
4.
5.
6.
F
T
T
T
T
T
II. Multiple Choice
7. F
8. T
9. T
10. F
11. T
12. T
1.
2.
3.
4.
5.
a, b, d
a
b, c, d
b, c, d, e
b, c
6. a, b
7. b
8. a, c, e
9. b, c, d, e
10. d