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FINAL EXAMINATION
NEUR 1650 - STRUCTURE OF THE NERVOUS SYSTEM
December 11, 2010
Total Points: 164
MULTIPLE CHOICE. Circle the letter(s) corresponding to ALL correct answers to each question.
There will always be one and there may be more than one correct answer. (90 points)
1. Which of the following are derived from the basal plate of the neural tube?
a.
b.
c.
d.
e.
gamma motorneurons of the thoracic spinal cord
neurons of layer 5 of the precentral gyrus
dorsal motor nucleus of the vagus
ganglia of the sympathetic chain
nucleus of the solitary tract
2. The anterior (or ventral) funiculus of the cervical spinal cord contains axons of neurons whose cell
bodies lie in
a.
b.
c.
d.
e.
the red nucleus
Clarke’s column (dorsal nucleus of Clarke)
the lateral vestibular nucleus
the fastigial nucleus
the brainstem reticular formation
3. Prof. Ziggy B. Goode has discovered a novel a G-protein coupled receptor that is exclusively
expressed in preganglionic autonomic motorneurons. The receptor is trafficked throughout the
plasma membrane of these cells, and is thus present in their axons, dendrites and cell bodies. Using
an antibody against this GPCR, Ziggy can expect to find immunohistochemical staining in
a.
b.
c.
d.
e.
the oculomotor nerve (III)
the glossopharyngeal nerve (IX)
sympathetic chain ganglia
the dorsal longitudinal fasciculus
axons making synaptic contact with smooth muscle of the blood vessels
4. Intralaminar and midline thalamic nuclei
a.
b.
c.
d.
e.
receive input from the brainstem reticular formation
are a major target of the neospinothalamic tract
are sometimes referred to as the “non-specific” thalamic nuclei
project more heavily to the granular layer than to the supragranular layers of the neocortex
project to the striatum
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5. Layer 5 of the neocortex
a. contains more large pyramidal cells than layer 4
b. is the main target of input from "feedforward" pathways from areas placed lower (earlier)
in the cortical hierarchy.
c. is the main source of axons entering the corpus callosum
d. is largely absent in the primary motor cortex
e. is the main source of corticobulbar projections
6. Which of the following could interfere with your ability to feel pain when a waiter spills a boiling hot
double-shot soy latte on your right thigh?
a.
b.
c.
d.
e.
selective silencing of A-delta and C fibers in spinal nerves of all lumbar segments
bilateral transection of the spinal trigeminal tracts
damage to the right gracile fasciculus at spinal segment C6
damage to the right anterior and lateral funiculi at spinal segment C3
a lesion in the lateral half of the left medulla
7. A ganglion cell in the nasal retina of the right eye gives rise to an axon that may synapse in
a.
b.
c.
d.
e.
the accessory optic nuclei
the left superior colliculus
layer 5 of the lateral geniculate nucleus of the right thalamus
layer 6 of the lateral geniculate nucleus of the left thalamus
layer 4 of the left striate cortex
8. Vestibular hair cells
a.
b.
c.
d.
are neurons
release transmitter onto processes of neurons in the spiral ganglion
change their membrane potential in responses to deflection of their stereocilia
responding to angular rotation of the head are located within the crista ampullaris of the
semicircular canals
e. responding to the force of gravity when the head is upright are found in the macula of the
sacculus
9. The inferior colliculus
a. is the first site in the ascending auditory pathway where signals from the two ears are
compared
b. is part of the tectum of the midbrain
c. is an obligatory synaptic waystation in the ascending auditory pathway to cortex
d. receives input from both the left and right cochlear nuclei
e. projects to the medial geniculate nucleus of the thalamus
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10. The olfactory bulb
a.
b.
c.
d.
e.
receives direct synaptic input from olfactory receptor neurons in the olfactory epithelium
contains projection neurons called tufted cells
sends direct axonal projections to the cerebral cortex
sends direct axonal projections to the corticomedial nucleus of the amygdala
restricts contacts between receptor cells and mitral cells to synaptic zones called glomeruli
11. The myotatic reflex (i.e., the stretch or "knee-jerk" reflex)
a. is mediated by monosynaptic contacts between secondary (Class II) spindle afferents and
gamma motorneurons
b. is mediated by monosynaptic contacts between primary (Class Ia) spindle afferents and
alpha motorneurons
c. cannot be evoked from the extraocular muscles (e.g., lateral rectus)
d. produces, in part, inhibition of motorneurons innervating the muscle antagonistic to the one
that was stretched
e. serves mainly to protect the body from potential tissue damage
12. Certain descending spinal tracts are known to be involved primarily in the control of muscles of the
limbs rather than of the neck and trunk. The neuronal cell bodies from which the axons in these
spinal tracts originate can found in
a.
b.
c.
d.
e.
the dentate nucleus of the cerebellum
the red nucleus
the pontine reticular formation
the superior colliculus
the medial vestibular nucleus
13. Purkinje cells of the cerebellar cortex
a.
b.
c.
d.
e.
are postsynaptic to parallel fibers
are postsynaptic to axons arising from the granule cells of the cerebellar cortex
make direct synaptic contact with cells of the interposed nucleus
release GABA from their axon terminals
receive synaptic inputs from a larger number of climbing fibers than they do from parallel
fibers
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14. The paramedian (or intermediate) zone of the cerebellum is functionally associated
a.
b.
c.
d.
e.
more with the contralateral cerebral cortex than with the ipsilateral cortex
more with the contralateral spinal cord than with the ipsilateral cord
more with the vestibular nuclei than with the dorsal spinocerebellar tract
more with the fastigial nucleus than with the interposed nucleus
more with regulation of prefrontal association cortex than of premotor cortex
15. The thalamic nuclei that relay signals from the basal ganglia to the neocortex
a. receive direct input from the putamen
b. receive direct input from the ventral pallidum
c. receive direct input from the pars compacta of the substantia nigra
d. include the mediodorsal nucleus
e. project in part to the frontal eye fields
16. The hippocampal formation
a.
b.
c.
d.
e.
is part of the cerebral cortex
receives information from the neocortex by way of the entorhinal cortex
projects directly to the septal nuclei by way of the fornix
borders the lateral ventricle
is a site of adult neurogenesis
17. Physiological responses to the drop in blood pressure during hemorrhage involve
a.
b.
c.
d.
inputs to the midbrain from sensory fibers in the glossopharyngeal nerve
increased secretion of vasopressin in the posterior pituitary
relay of viscerosensory signals from the nucleus of the solitary tract to the hypothalamus
direct release of hormones from parvocellular hypothalamic neurons into fenestrated
capillaries in the anterior pituitary
e. neuroendocrine, autonomic and behavioral components
18. Dr. Beulah G. Muffleduffer deposits a dollop of Magma Red, a powerful retrograde tracer, into the
spinomedullary junction of a mouse, saturating the caudal medulla and segments C1 and C2 of the
spinal cord bilaterally. After appropriate survival time and histological processing, which of the
following structures should contain retrograde cell-labeling? (Warning: Magma Red has a serious
fiber-of-passage problem!!)
a.
b.
c.
d.
e.
dorsal root ganglia of spinal segment S1
marginal nucleus of spinal segment S1
internal segment of the globus pallidus
primary motor cortex
Clarke’s column
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TRUE OR FALSE. Circle the correct letter. (30 points).
T F 1. Retinal bipolar cells make glutamatergic, sign-conserving synapses onto both ON- and OFFcenter ganglion cells.
T F 2.
Noxious heat on a groundhog's left forepaw will trigger reflex extension of its right forepaw.
T F 3. Ribosomes are a prominent intracellular organelle of axons.
T F 4. Pyramidal cells near the boundary between cortical areas 17 and 18 project through the
splenium of the corpus callosum to the same region in the contralateral hemisphere.
T F 5. Mice in the GENSAT database are transgenic animals that express green fluorescent protein
under the control of the promoter for a single gene.
T F 6. Cells of the autonomic ganglia are derived from the neural plate.
T F 7.
In the thoracic spinal cord, axons in the dorsal columns carrying ascending signals from sacral
levels lie lateral to those arising from lumbar levels.
T F 8. The medial longitudinal fasciculus (MLF) is made up in part by the axons of neurons in the
hypothalamus destined for the visceromotor nuclei of the cranial nerves.
T F 9. The spinal component of the spinal accessory nerve (11th cranial nerve) innervates the larynx.
T F 10. Confocal microscopy uses lasers to generate hi-resolution fluorescence micrographs with
little blurring from out-of-focus structures in the tissue.
T F 11. The cuneocerebellar tract conveys proprioceptive information from the wrist joint to the
spinocerebellum.
T F 12.
The paramedian (or intermediate) zone of the cerebellum receives convergent input from
spinocerebellar and pontocerebellar afferents.
T F 13.
Primary sensory axons of Class IV (C fibers) ascend in the archispinothalamic tract to
terminate in the brainstem reticular formation.
T F 14.
Thalamic cells with small mechanosensory receptive fields on the skin of lips are most likely
to be found in the ventral posteromedial nucleus (VPM).
T F 15. Light reduces the release of glutamate from retinal cones.
T F 16. The primary auditory cortex contains a systematic map of sound frequency.
T F 17.
The solitary tract contains primary viscerosensory axons that enter the brainstem with cranial
nerve X (vagus).
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T F 18. Axons within the ventral spinocerebellar tract on the left side of the spinal cord carry
information about the status of interneurons in the spinal grey on the right.
T F 19.
The dentate nucleus of the right cerebellum projects directly to the right ventrolateral
thalamic nucleus.
T F 20.
The anterior (or ventral) corticospinal tract influences spinal motorneurons innervating the
neck and trunk more than those supplying the wrist and ankle.
T F 21. The cortical inputs to the pontine gray are primarily crossed.
T F 22. The subthalamic nucleus and external division of the globus pallidus are reciprocally
interconnected by direct synaptic links.
T F 23. The putamen, internal segment of the globus pallidus, and pars reticulata of the substantia
nigra all exhibit inhibitory effects on their output targets.
T F 24.
Hemisection of the left half of the spinal cord produces, below the level of the cut, a loss of
thermal sensation on the right and spasticity and proprioceptive deficits on the left.
T F 25. The main (or principal) nucleus of the trigeminal nerve lies rostral to the lateral apertures.
T F 26. Some retinal ganglion cells are photoreceptors.
T F 27. The spinal cord contains preganglionic autonomic motorneurons of both the sympathetic and
parasympathetic varieties.
T F 28. The paleospinothalamic tract terminates in the midline and intralaminar thalamic nuclei.
T F 29.
The major projection of the pulvinar is to the parieto-tempero-occipital association cortex.
T F 30. Toxins in the blood can affect the circumventricular organs to trigger vomiting.
T F 00. Democracy is the process by which people choose the person who'll get the blame.
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CLINICAL CASE Read the following case history and answer the short-answer questions as
concisely (but precisely) as possible. (6 points).
A 59-year-old woman complained of headaches, difficulty speaking, and loss of strength in her right arm
and leg. The headaches had appeared about 2 months earlier, and the problems with speech several
weeks after that. The patient was taking medication for high blood pressure, and reported that she was a
heavy smoker and moderately heavy drinker. There was no sign of intoxication at the time of
examination. Cardiac sounds, breathing and pulse rate were within normal limits, but blood pressure was
elevated.
The patient was alert and accurately reported the date, time and place of the exam. She had no difficulty
comprehending spoken or written instructions. Nor did she have any difficulty naming common objects
or repeating word lists. Her speech was, however, rather garbled and "thickened", as if her tongue were
swollen or clumsy (dysarthria). The patient's tongue turned to the left when she was instructed to extend
it. The dorsal surface of the tongue was wrinkled on the left, and fasciculations were noted there as well.
Extraocular movements were brisk and complete, and all other cranial nerve functions appeared
preserved.
The right arm and leg were clearly weaker than the left arm and leg. Deep tendon reflexes were
exaggerated on the right, as was resting muscle tone. The right foot exhibited a Babinski reflex.
Otherwise, motor function appeared normal.
There was a mild decrease in two-point discriminability for cutaneous stimuli on the right upper and
lower limbs. There was also some deficit in proprioception for the right arm and leg, but other sensory
systems appeared intact. In particular, there was no sensory impairment for vibratory sensation or twopoint discrimination on the face, nor for pinprick or thermal sensation anywhere on the skin.
1. Where in the nervous system is this patient's lesion? Be as specific as possible about level, laterality
and location within the cross-section.
2. What fiber tracts, functional systems or nuclei appear to have been damaged by the lesion?
3. What accounts for the dissociation of the laterality of the motor deficits in the tongue with those in the
arms and legs?
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FILL IN THE BLANK (38 points) Fill in each blank with the name of the structure indicated by the
matching number in the photocopied figures at the back of the exam. Original versions of the
photocopies with somewhat better reproductions are available for viewing at the front of the room.
You should try to be quite specific, but we are not looking for extraordinary detail. As a hypothetical
example, "cortex of the temporal lobe" would be a more complete answer than "cerebral
hemisphere," but we wouldn't expect "layer 5b of Brodmann's area 22 of the right hemisphere".
a. _______________________________________________________________________________
b. (blood vessel)___________________________________________________________________
c. (blood vessel)___________________________________________________________________
d. (blood vessel)___________________________________________________________________
e. (nerve)__________________________________________________________________________
f. (blood vessel)_____________________________________________________________________
g. (blood vessel)___________________________________________________________________
h. (blood vessel)___________________________________________________________________
i. _______________________________________________________________________________
j. _______________________________________________________________________________
k. _______________________________________________________________________________
l. _______________________________________________________________________________
m. _______________________________________________________________________________
n. _______________________________________________________________________________
o. _______________________________________________________________________________
p. _______________________________________________________________________________
q. _______________________________________________________________________________
r. (grey matter)_____________________________________________________________________
s. _______________________________________________________________________________
t. (grey matter)_____________________________________________________________________
u. _______________________________________________________________________________
v. _______________________________________________________________________________
w. _______________________________________________________________________________
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x. _______________________________________________________________________________
y. _______________________________________________________________________________
z. _______________________________________________________________________________
aa. (space)_________________________________________________________________________
bb. _______________________________________________________________________________
cc. _______________________________________________________________________________
dd. _______________________________________________________________________________
ee. _______________________________________________________________________________
ff. _______________________________________________________________________________
gg. _______________________________________________________________________________
hh. _______________________________________________________________________________
ii. _______________________________________________________________________________
jj. _______________________________________________________________________________
kk. _______________________________________________________________________________
ll. _______________________________________________________________________________
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