neuroanatomy 3rd Comprehensive Examination 51 - 97

Question 1

51. Each of the following statements concern-
    ing the cavernous sinus is true EXCEPT
    (A) it surrounds the sella turcica
    (B) it receives blood from the ophthalmic veins
    (C) it contains fibers from the superior cervi-
    cal ganglion
    (D) it contains the mandibular nerve
    (E) it contains cranial nerves III, TV, and VI

Answer 1

D. The mandibular nerve (CN V-3) exits the skull through the foramen ovale; it is not found
in the cavernous sinus

Question 2

52.	The posterior cerebral artery supplies all
of the following structures EXCEPT
(A)	the parahippocampal gyrus
(B)	the temporal pole
(C)	the occipital lobe
(D)	the midbrain
(E)	the thalamus

Answer 2

52-B. The temporal pole is supplied by the anterior temporal artery, which is a branch of the
middle cerebral artery.

Question 3

53.	The neural crest gives rise to all of the fol-
lowing cells EXCEPT
(A)	cells of the sympathetic trunk
(B)	cells of the suprarenal medulla
(C)	dorsal root ganglion cells
(D)	Schwann cells
(E)	ventral horn cells

Answer 3

53-E. Ventral horn neurons develop in the basal plate of the mantle layer of the neural tube.

Question 4

54. Each of the following statements concern-
    ing spinal cord nuclei is true EXCEPT
    (A) the parasympathetic nucleus is located in
    the lateral horn
    (B) the intermediolateral nucleus extends
    from Tl to L3
    (C) the spinal accessory nucleus extends from
    CI to C6
    (D) the phrenic nucleus extends from C3 to C6
    (E) the spinal border cells extend from LI to
    S3

Answer 4

54-A. The parasympathetic nucleus of the spinal cord is located in the ventral horn (Rexed lam-
ina VII) at sacral levels S2 to S4.

Question 5

55. Each of the following statements concern-
    ing the fasciculus cuneatus is true EXCEPT
    (A) its neurons of origin are in the dorsal horn
    (B) its fibers project to a nucleus in the
    medulla
    (C) it contains input from the upper extremity
    (D) it mediates two-point tactile discrimination
    (E) its fibers do not decussate in the spinal
    cord

Answer 5

55-A. The neurons of origin (i.e., first-order neurons) of the gracile fasciculus are found in the
dorsal root ganglia from T5—S5. Second-order neurons are located in the nucleus gracilis of the
medulla. Third-order neurons are located in the contralateral ventral posterolateral nucleus of
the thalamus.

Question 6

56. Each of the following statements concern-
    ing the spinocerebellar tracts is true EXCEPT
    (A) the dorsal spinocerebellar tract originates
    from the nucleus dorsalis of Clarke
    (B) the spinocerebellar tracts receive input
    from muscle spindles and Golgi tendon or-
    gans
    (C) the cuneocerebellar tract originates in the
    medulla
    (D) the ventral spinocerebellar tract origi-
    nates from the spinal border cells of the
    ventral horns
    (E) the ventral spinocerebellar tract enters
    the cerebellum through the inferior cere-
    bellar peduncle

Answer 6

56-E. The ventral spinocerebellar tract enters the cerebellum through the superior cerebellar
peduncle. The dorsal spinocerebellar and the cuneocerebellar tracts enter the cerebellum
through the inferior cerebellar peduncle.

Question 7

57. Each of the following statements concern-
    ing the lateral spinothalamic tract is true EX-
    CEPT
    (A) it mediates pain and temperature sensa-
    tion
    (B) its second-order neurons are located in
    the dorsal horn
    (C) it decussates in the ventral white com-
    missure
    (D) axons of its first-order neurons enter the
    dorsolateral tract of Lissauer
    (E) it projects to the ventral posteromedial
    (VPM) nucleus of the thalamus

Answer 7

57-E. The lateral spinothalamic tract projects to the ventral posterolateral (VPL) nucleus of the
thalamus. The ventral posteromedial (VPM) nucleus receives pain fibers via the trigeminal sys-
tem (i.e., the ventral trigeminothalamic tract).

Question 8

58. Each of the following statements concern-
    ing the pons is true EXCEPT
    (A) it contains the nucleus that innervates
    the stapedius muscle
    (B) it contains the nucleus that innervates
    the tensor tympani muscle
    (C) it contains the mesencephalic nucleus
    (D) it contains a nucleus that innervates the
    parotid gland
    (E) it contains the center for lateral conjugate
    gaze

Answer 8

58-D. The parotid gland receives parasympathetic innervation from the glossopharyngeal nerve
(CN IX). The inferior salivatory nucleus of CN IX is found in the medulla; it projects pregan-
glionic fibers via the lesser petrosal nerve (CN IX) to the otic ganglion. The otic ganglion projects
postganglionic fibers to the parotid gland.

Question 9

59. In the brainstem, intra-axial fibers of the
    facial nerve are closely associated with all of
    the following structures EXCEPT
    (A) the abducent nucleus
    (B) the medial longitudinal fasciculus (MLF)
    (C) the medial lemniscus
    (D) the spinal nucleus and tract of CN V
    (E) the middle cerebellar peduncle

Answer 9

59-C. The intra-axial fibers of the facial nerve are closely associated with the abducent nucleus,
the medial longitudinal fasciculus (MLF), the spinal trigeminal tract and nucleus, and the mid-
dle cerebellar peduncle. Lesions involving the facial nerve within the pons frequently include
these associated structures. The medial lemniscus lies more distant (medial) to the intra-axial
fibers of the facial nerve.

Question 10

60. The mandibular nerve innervates all of
    the following structures EXCEPT
    (A) the mucosa of the anterior two-thirds of
    the tongue
    (B) the posterior belly of the digastric muscle
    (C) the tensor tympani muscle
    (D) the external auditory meatus
    (E) the muscles of mastication

Answer 10

60-B. The mandibular nerve (CN V-3) innervates the anterior belly of the digastric muscle. The
facial nerve (CN VII) innervates the posterior belly of the digastric muscle.

Question 11

61. Each of the following structures is part of
    the auditory pathway EXCEPT
    (A) the spiral ganglion
    (B) the cochlear nuclei
    (C) the trapezoid body
    (D) the inferior olivary nucleus
    (E) the nucleus of the inferior colliculus

Answer 11

61-D. The inferior olivary nucleus is a cerebellar relay nucleus located in the medulla; it is not part
of the auditory system. However, the superior olivary nucleus has an important role in the auditory
pathway; it receives input from the cochlear nuclei and projects to, and forms, the lateral lemniscus.

Question 12

62. Each of the following statements concern-
    ing the vestibular nuclei is true EXCEPT
    (A) they receive input from semicircular ducts
    (B) they receive input from the saccule and
    utricle
    (C) they receive input from the spiral ganglion
    (D) they project to cranial nerves III, IV, and
    VI
    (E) they have reciprocal connections with the
    flocculonodular lobe

Answer 12

62-C. The vestibular nuclei receive input from the vestibular ganglion, which is found in the
base of the internal auditory meatus. The spiral ganglion innervates the cochlear organ of Corti
and gives rise to the cochlear nerve (CN VIII).

Question 13

63. Each of the following statements concern-
    ing the ventral trigeminothalamic tract is true
    EXCEPT
    (A) it mediates pain and temperature sensa-
    tion from the head
    (B) it receives input from cranial nerves VII,
    IX, and X
    (C) second-order neurons are found in the
    caudal spinal trigeminal nucleus
    (D) it is a crossed pathway
    (E) decussation of pain fibers occurs in the
    pons

Answer 13

63-E. The ventral trigeminothalamic tract mediates pain and temperature sensation. The sec-
ond-order neurons mediating pain are located in the caudal third of the spinal trigeminal nu-
cleus. Decussation of these fibers occurs in the medulla. Fibers that mediate the corneal reflex
decussate at a higher level. Thus, trigeminal tractotomies at lower medullary levels (e.g., fora-
men magnum) may spare the corneal reflex fibers while abolishing pain sensation from the face.

Question 14

64. Each of the following statements concern-
    ing the medial longitudinal fasciculus (MLF) is
    true EXCEPT
    (A) it contains ascending and descending fibers
    (B) it contains vestibular fibers that project to
    all ocular motor nuclei
    (C) it is very close to the internal genu of CN
    VII
    (D) it is very close to the motor nucleus of CN
    V
    (E) it extends from the spinal cord to the mid-
    brain

Answer 14

64-D. The medial longitudinal fasciculus (MLF) extends from the spinal cord to the rostral mid-
brain. It contains ascending vestibular fibers to the oculomotor nuclei of cranial nerves III, IV,
and VI; abducent fibers (i.e., fibers from the lateral gaze center of the pons) to the contralateral
oculomotor complex (medial rectus subnucleus); and descending vestibulospinal fibers. The
MLF is a paramidline structure that lies distant to the motor nucleus of the trigeminal nerve
(CNV).

Question 15

65. Each of the following statements concern-
    ing the vestibular nerve is true EXCEPT
    (A) it consists of the central processes of bipo-
    lar neurons
    (B) it traverses the internal auditory meatus
    (C) it projects direct fibers to the cerebellar
    cortex
    (D) it enters the brainstem at the ponto-
    medullary junction
    (E) it does not contain efferent fibers

Answer 15

65-E. The vestibular nerve contains efferent fibers that arise from neurons in the superior and
medial vestibular nuclei. These inhibitory fibers innervate the hair cells of the cristae ampullares
and the maculae of the utricle and saccule.

Question 16

66. Transection of the facial nerve between the
    geniculate ganglion and the chorda tympani
    results in the loss of all of the following EX-
    CEPT
    (A) taste sensation from the anterior two-
    thirds of the tongue
    (B) innervation of the lacrimal gland
    (C) innervation of the sublingual and sub-
    mandibular glands
    (D) the corneal reflex
    (E) the ability to wrinkle the brow on the af-
    fected side

Answer 16

66-B. Transection of the facial nerve (CN VII) between the geniculate ganglion and the chorda
tympani spares the general visceral efferent (GVE) fibers from the superior salivatory nucleus
that synapse in the pterygopalatine ganglion and innervate the lacrimal gland. These pregan-
glionic lacrimal fibers are located in the major petrosal nerve (CN VII).

Question 17

67. Each of the following statements concern-
    ing the nucleus ambiguus is true EXCEPT
    (A) it contains preganglionic parasympa-
    thetic neurons that innervate the heart
    (B) it innervates the musculature of the lar-
    ynx and pharynx
    (C) it is located near the hypoglossal nucleus
    (D) it is located near the spinal trigeminal nu-
    cleus and tract
    (E) it sends special visceral efferent (SVE)
    fibers to cranial nerves IX, X, and XI

Answer 17

67-C. The nucleus ambiguus of cranial nerves IX, X, and XI is located in the lateral medulla,
midway on a line connecting the hypoglossal nucleus and the postolivary sulcus; it is not near
the hypoglossal nucleus of CN XII. The nucleus ambiguus is supplied by the posterior inferior
cerebellar artery (PICA), and the hypoglossal nucleus is supplied by the ventral spinal artery, a
branch of the vertebral artery.

Question 18

68. Each of the following statements concern-
    ing Purkinje cells is true EXCEPT
    (A) they project to the cerebellar nuclei
    (B) they project to the thalamus
    (C) they project to the vestibular nuclei
    (D) they are inhibited by basket cells
    (E) their neurotransmitter is gamma-amino-
    butyric acid (GABA)

Answer 18

68-B. Purkinje cells project only to the vestibular and cerebellar nuclei. One of the cerebellar
nuclei is the dentate nucleus, which projects to the contralateral ventral lateral nucleus of the
thalamus, which in turn projects to the motor cortex (area 4 of the precentral gyrus).

Question 19

69. Each of the following statements concern-
    ing the cerebellar peduncles is true EXCEPT
    (A) the superior cerebellar peduncle is the
    major efferent pathway from the cerebel-
    lum
    (B) the middle cerebellar peduncle attaches
    the cerebellum to the midbrain
    (C) the inferior cerebellar peduncle includes
    the juxtarestiform body
    (D) the ventral spinocerebellar tract is found
    in the superior cerebellar peduncle
    (E) the neocortex influences the cerebellum
    via the middle cerebellar peduncle

Answer 19

69-B. The superior cerebellar peduncle connects the cerebellum to the pons and midbrain. The
middle cerebellar peduncle connects the cerebellum to the pons. The neocortex influences the
cerebellum via the middle cerebellar peduncle. The inferior cerebellar peduncle connects the
cerebellum to the medulla.

Question 20

70. Each of the following statements concern-
    ing the retina is true EXCEPT
    (A) it is of diencephalic origin
    (B) the fovea centralis contains rods and
    cones
    (C) the optic disk is the blind spot
    (D) the macula lutea surrounds the fovea cen-
    tralis
    (E) the retina has a dual blood supply

Answer 20

70-B. The fovea centralis of the retina is the site of highest visual acuity; it contains only cones.
The retina has a dual blood supply. The choriocapillaris perfuses the outer layers of the retina,
including the outer plexiform layer. The central retinal artery supplies the remaining inner lay-
ers of the retina.

Question 21

71. Each of the following statements concern-
    ing transection of the left optic tract is true
    EXCEPT
    (A) the direct pupillary light reflex is unaf-
    fected
    (B) the consensual pupillary light reflex is un-
    affected
    (C) it causes ganglion cell degeneration in the
    right nasal hemiretina
    (D) it causes cell degeneration in the right lat-
    eral geniculate body
    (E) it causes a right homonymous hemianopia

Answer 21

71-D. Transection of the optic tract results in transsynaptic (transneuronal) degeneration of
cells in the ipsilateral lateral geniculate body. The optic tract contains pupillary and visual fibers
from the contralateral nasal hemiretina and from the ipsilateral temporal hemiretina. Pupillary
fibers from both eyes are present in the optic tract; therefore, interruption of one optic tract does
not abolish pupillary light reflexes.

Question 22

72. Each of the following statements concern-
    ing ocular motility is true EXCEPT
    (A) the frontal eye field is located in the infe-
    rior frontal gyrus
    (B) the occipital eye field is located in areas 18
    and 19
    (C) the subcortical center for vertical conju-
    gate gaze is located at the junction of the
    midbrain-diencephalon
    (D) the subcortical center for lateral conju-
    gate gaze is located in the abducent nu-
    cleus
    (E) stimulation of the frontal eye field causes
    contralateral deviation of the eyes

Answer 22

72-A. The frontal eye field is found in the middle frontal gyrus (area 8). Destruction of a frontal
eye field results in a deviation of the eyes toward the side of the lesion.

Question 23

73. Each of the following statements concern-
    ing autonomic innervation of the eye is true
    EXCEPT
    (A) stimulation of the intermediolateral cell
    column at Tl causes ipsilateral mydriasis
    (B) transection of the cervical sympathetic
    trunk causes ptosis and miosis
    (C) stimulation of the Edinger-Westphal nu-
    cleus causes miosis and ptosis
    (D) destruction of the ciliary ganglion inter-
    rupts both sympathetic and parasympa-
    thetic postganglionic fibers en route to the
    globe
    (E) destruction of the superior cervical gan-
    glion causes ipsilateral Horner syndrome

Answer 23

73-C. The Edinger-Westphal nucleus contains preganglionic parasympathetic neurons that in-
nervate the sphincter muscle of the iris and the ciliary muscle. Stimulation of this nucleus causes
a constructed (miotic) pupil but does not cause ptosis. Severe ptosis results from damage to the
superior division of the oculomotor nerve, which innervates the superior levator palpebrae.
Slight ptosis results from sympathetic paralysis of the Miiller superior tarsal muscle (smooth
muscle) in Horner syndrome. Postganglionic sympathetic vasomotor fibers pass through the cil-
iary ganglion without synapse. Postganglionic sympathetic pupillodilator fibers circumvent the
ciliary ganglion and reach the iris via the nasociliary and long ciliary nerves.

Question 24

74. Parasympathetic stimulation causes all of
    the following reactions EXCEPT
    (A) profuse watery secretion of the salivary
    glands
    (B) constriction of the lumina of the bronchial
    tubes
    (C) ejaculation
    (D) increased gastrointestinal motility
    (E) penile erection

Answer 24

74-C. Although erection is caused by parasympathetic stimulation, ejaculation is the result of
sympathetic stimulation. Sacral somatic motoneurons also play a role in ejaculation. They evoke
spasmodic contractions of the bulbocavernosus and ischiocavernosus muscles.

Question 25

75.	Horner syndrome can result from all of the
following lesions EXCEPT
(A)	hemisection of the spinal cord at C7
(B)	occlusion of the posterior inferior cerebel-
lar artery
(C)	an aneurysm of the cavernous sinus
(D)	a tumor of the apex of the lung
(E)	a tumor of the base of the pons

Answer 25

75-E. Horner syndrome results when sympathetic input to the eye, at any level, is interrupted.
Descending sympathetic pathways to the ciliospinal center of the thoracic cord (T1-T2) are lo-
cated in the lateral tegmentum of the brainstem and in the lateral funiculus of the spinal cord Horner syndrome is seen in posterior inferior cerebellar artery (PICA), anterior inferior cerebel-
lar artery (AICA), and Brown-Sequard syndromes; it is frequently associated with lung (Pan-
coast tumor) and neck tumors that encroach on the sympathetic trunk and cervical sympathetic
ganglia. Disease of the neck and cavernous sinus may also cause Horner syndrome.

Question 26

76. Each of the following statements concern-
    ing olfactory receptor cells is true EXCEPT
    (A) they are first-order neurons in the olfac-
    tory pathway
    (B) they are unmyelinated bipolar neurons
    with central processes that form the first
    cranial nerve
    (C) they synapse with mitral cells in the ol-
    factory bulb
    (D) they are incapable of regeneration
    (E) they enter the skull via the lamina
    cribrosa of the ethmoid bone

Answer 26

76-D. Olfactory receptor cells are located in the olfactory mucosa of the superior nasal conchae
and opposing septum. These cells have a life span of 1 month and are capable of regeneration.

Question 27

77. Each of the following structures is a part of
    the gustatory pathway EXCEPT
    (A) cranial nerves VII, IX, and X
    (B) the solitary tract and nucleus
    (C) the parabrachial nucleus
    (D) the ventral posterolateral (VPL) nucleus
    (E) area 43 of the parietal lobe

Answer 27

77-D. The gustatory (taste) pathway [special visceral afferent (SVA)] includes taste buds of the
tongue; cranial nerves VII, IX, and X; solitary tract and nucleus; central tegmental tract;
parabrachial nucleus of the pons; ventral posteromedial (VPM) nucleus of the thalamus; and
primary olfactory cortex (area 43).

Question 28

78.	All of the following structures are present
in the cavernous sinus or its lateral wall EX-
CEPT
(A)	the ophthalmic nerve
(B)	the maxillary nerve
(C)	the mandibular nerve
(D)	cranial nerves III, IV, and VI
(E)	postganglionic sympathetic fibers

Answer 28

78-C. The mandibular nerve (CN V-3) is not located in the cavernous sinus. The cavernous si-
nus includes cranial nerves III, IV, VI, V-l, V-2, postganglionic sympathetic fibers, and the in-
ternal carotid artery.

Question 29

The response options for items 79-83 are the
same. You will be required to select one answer
for each item in the set.
(A)	Abducent nerve
(B)	Accessory nerve
(C)	Facial nerve
(D)	Glossopharyngeal nerve
(E)	Hypoglossal nerve
(E)	Oculomotor nerve
(F)	Olfactory nerve
(G)	Optic nerve
(H)	Trigeminal nerve
(I)	Trochlear nerve
(J)	Vagal nerve
(K) Vestibulocochlear nerve
Match each description with the most appro-
priate cranial nerve.
79.	Provides the efferent limb of the corneal
reflex

Answer 29

79-C. The facial nerve provides the efferent limb of the corneal reflex.

Question 30

The response options for items 79-83 are the
same. You will be required to select one answer
for each item in the set.
(A)	Abducent nerve
(B)	Accessory nerve
(C)	Facial nerve
(D)	Glossopharyngeal nerve
(E)	Hypoglossal nerve
(E)	Oculomotor nerve
(F)	Olfactory nerve
(G)	Optic nerve
(H)	Trigeminal nerve
(I)	Trochlear nerve
(J)	Vagal nerve
(K) Vestibulocochlear nerve
Match each description with the most appro-
priate cranial 80.	Is derived from the walls of the dien-
cephalic vesicle
nerve.

Answer 30

80-G. The optic nerve is derived from the wall of the diencephalic vesicle.

Question 31

Questions 79-83
The response options for items 79-83 are the
same. You will be required to select one answer
for each item in the set.
(A)	Abducent nerve
(B)	Accessory nerve
(C)	Facial nerve
(D)	Glossopharyngeal nerve
(E)	Hypoglossal nerve
(E)	Oculomotor nerve
(F)	Olfactory nerve
(G)	Optic nerve
(H)	Trigeminal nerve
(I)	Trochlear nerve
(J)	Vagal nerve
(K) Vestibulocochlear nerve
Match each description with the most appro-
priate cranial nerve.
81.	Is often damaged in the process of
transtentorial herniation

Answer 31

81-E. The oculomotor nerve is often damaged in the process of transtentorial herniation.

Question 32

The response options for items 79-83 are the
same. You will be required to select one answer
for each item in the set.
(A)	Abducent nerve
(B)	Accessory nerve
(C)	Facial nerve
(D)	Glossopharyngeal nerve
(E)	Hypoglossal nerve
(E)	Oculomotor nerve
(F)	Olfactory nerve
(G)	Optic nerve
(H)	Trigeminal nerve
(I)	Trochlear nerve
(J)	Vagal nerve
(K) Vestibulocochlear nerve
Match each description with the most appro-
priate cranial nerve.
82.	Mediates the sensory and motor innerva-
tion of pharyngeal arches 4 and 6

Answer 32

82-J. The vagal nerve mediates the sensory and motor innervation of the pharyngeal arches 4
and 6.

Question 33

Questions 79-83
The response options for items 79-83 are the
same. You will be required to select one answer
for each item in the set.
(A)	Abducent nerve
(B)	Accessory nerve
(C)	Facial nerve
(D)	Glossopharyngeal nerve
(E)	Hypoglossal nerve
(E)	Oculomotor nerve
(F)	Olfactory nerve
(G)	Optic nerve
(H)	Trigeminal nerve
(I)	Trochlear nerve
(J)	Vagal nerve
(K) Vestibulocochlear nerve
Match each description with the most appro-
priate cranial nerve
83.	Innervates the muscle that depresses, in-
torts, and abducts the globe

Answer 33

83-1. The trochlear nerve innervates the muscle that depresses, intorts, and abducts the globe

Question 34

The response options for items 84—85 are the
same. You will be required to select one answer
for each item in the set.
(A) Basal ganglia
(B) Cerebellum
(C) Frontal lobe
(D) Occipital lobe
(E) Parietal lobe
(F) Temporal lobe
(G) Subthalamic nucleus
(H) Ventral horn
For each patient described, select the most
likely involved neurologic substrate.
84. A 50-year-old policeman complains of a
tremor in both hands. This tremor is most ob-
vious at rest. While the man is reaching for an
object, the tremor disappears.

Answer 34

84-A. Parkinson disease is characterized by a symptom triad: tremor (“pill-rolling”), rigidity,
and hypokinesia. The substantia nigra (a basal ganglion) bears the brunt of the cell loss. (Other
basal ganglia are the caudate nucleus, putamen, and globus pallidus.) Cerebellar disease is char-
acterized by tremor (intention tremor), ataxia, and hypotonia. Destruction of the subthalamic
nucleus results in contralateral hemiballismus

Question 35

Questions 84-85
The response options for items 84—85 are the
same. You will be required to select one answer
for each item in the set.
(A) Basal ganglia
(B) Cerebellum
(C) Frontal lobe
(D) Occipital lobe
(E) Parietal lobe
(F) Temporal lobe
(G) Subthalamic nucleus
(H) Ventral horn
For each patient described, select the most
likely involved neurologic substrate.
85. A 35-year-old tennis player is concerned
about weakness in his arms and hands, and he
notices a loss of muscle mass in the upper
limbs. His muscle stretch reflexes (MSRs) are
exaggerated in the lower extremities, and he
has muscle twitches in the upper limbs.

Answer 35

85-H. In amyotrophic lateral sclerosis (ALS), there is a loss of ventral horn cells and a loss of
cortical pyramidal cells that give rise to the pyramidal tract. This motor system disease consists
of an upper motor neuron component and a lower motor neuron component. There are no sen-
sory deficits in ALS.

Question 36

Questions 86-92
The response options for items 86-92 are the
same. You will be required to select one answer
for each item in the set.
(A)	Diencephalon
(B)	Medulla
(C)	Midbrain
(D)	Pons
(E)	Telencephalon
Match each of the following structures with the
appropriate part of the brain.
86.	Cerebral aqueduct

Answer 36

86-C. The cerebral aqueduct is located in the midbrain (mesencephalon). It interconnects the
third and fourth ventricles.

Question 37

Questions 86-92
The response options for items 86-92 are the
same. You will be required to select one answer
for each item in the set.
(A)	Diencephalon
(B)	Medulla
(C)	Midbrain
(D)	Pons
(E)	Telencephalon
Match each of the following structures with the
appropriate part of the brain.
87.	Cranial nerves III and IV

Answer 37

87-C. The tegmentum of the midbrain contains the nuclei of the oculomotor nerve (CN III) and
the trochlear nerve (CN IV). The midbrain also contains the mesencephalic nucleus of the trigem-
inal nerve (CN V).

Question 38

Questions 86-92
The response options for items 86-92 are the
same. You will be required to select one answer
for each item in the set.
(A)	Diencephalon
(B)	Medulla
(C)	Midbrain
(D)	Pons
(E)	Telencephalon
Match each of the following structures with the
appropriate part of the brain
88.	Caudate nucleus

Answer 38

88-E. The caudate nucleus, a basal ganglion, is located in the white matter of the telencephalon.
It forms the lateral wall of the frontal horn of the lateral ventricle.

Question 39

Questions 86-92
The response options for items 86-92 are the
same. You will be required to select one answer
for each item in the set.
(A)	Diencephalon
(B)	Medulla
(C)	Midbrain
(D)	Pons
(E)	Telencephalon
Match each of the following structures with the
appropriate part of the brain.
89.	Optic chiasma

Answer 39

89-A. The optic chiasma is located in the diencephalon. It lies between the anterior commissure
and the infundibulum of the pituitary gland (hypophysis).

Question 40

Questions 86-92
The response options for items 86-92 are the
same. You will be required to select one answer
for each item in the set.
(A)	Diencephalon
(B)	Medulla
(C)	Midbrain
(D)	Pons
(E)	Telencephalon
Match each of the following structures with the
appropriate part of the brain.
90.	Olive and the pyramid

Answer 40

90-B. The olive and the pyramid are prominent structures on the surface of the medulla. The
olive contains the inferior olivary nucleus; the pyramid contains the corticospinal tract.

Question 41

Questions 86-92
The response options for items 86-92 are the
same. You will be required to select one answer
for each item in the set.
(A)	Diencephalon
(B)	Medulla
(C)	Midbrain
(D)	Pons
(E)	Telencephalon
Match each of the following structures with the
appropriate part of the brain.
91.	Pineal gland

Answer 41

91-A. The pineal gland (epiphysis cerebri) is part of the epithalamus, which is a subdivision of
the diencephalon.

Question 42

Questions 86-92
The response options for items 86-92 are the
same. You will be required to select one answer
for each item in the set.
(A)	Diencephalon
(B)	Medulla
(C)	Midbrain
(D)	Pons
(E)	Telencephalon
Match each of the following structures with the
appropriate part of the brain.
92.	Cranial nerves IX, X, XI, and XII

Answer 42

92-B. Cranial nerves IX, X, XI, and XII are located in the medulla.

Question 43

Questions 93-97
The response options for items 93-97 are the
same. You will be required to select one answer
for each item in the set.
(A)	Astrocytes
(B)	Ependymal cells
(C)	Microglial cells
(D)	Oligodendrocytes
(E)	Schwann cells
Match each of the following descriptions with
the most appropriate type of cell.
93.	Are derived from the neural crest

Answer 43

93-E. Schwann cells of the peripheral nervous system (PNS) are neural crest derivatives.

Question 44

The response options for items 93-97 are the
same. You will be required to select one answer
for each item in the set.
(A) Astrocytes
(B) Ependymal cells
(C) Microglial cells
(D) Oligodendrocytes
(E) Schwann cells
Match each of the following descriptions with
the most appropriate type of cell.
94. May myelinate numerous axons

Answer 44

94-D. Oligodendrocytes of the central nervous system (CNS) may myelinate numerous axons.
Schwann cells myelinate only one internode.

Question 45

The response options for items 93-97 are the
same. You will be required to select one answer
for each item in the set.
(A) Astrocytes
(B) Ependymal cells
(C) Microglial cells
(D) Oligodendrocytes
(E) Schwann cells
Match each of the following descriptions with
the most appropriate type of cell.
95. Have filaments that contain glial fibrillary
acidic protein

Answer 45

95-A. The filaments of astrocytes contain fibrillary glial acidic protein (GFAP), a marker for as-
trocytes and astrocytic turner cells. Another biochemical marker is glutamine synthetase found
exclusively in astrocytes.

Question 46

The response options for items 93-97 are the
same. You will be required to select one answer
for each item in the set.
(A) Astrocytes
(B) Ependymal cells
(C) Microglial cells
(D) Oligodendrocytes
(E) Schwann cells
Match each of the following descriptions with
the most appropriate type of cell.
96. Myelinate only one internode

Answer 46

96-E. Schwann cells myelinate only one internode. Schwann cells are derived from the neural
crest; Schwann cells may proliferate to form tumors, Schwannomas (acoustic neurilemomas).

Question 47

The response options for items 93-97 are the
same. You will be required to select one answer
for each item in the set.
(A) Astrocytes
(B) Ependymal cells
(C) Microglial cells
(D) Oligodendrocytes
(E) Schwann cells
Match each of the following descriptions with
the most appropriate type of cell.
97. Arise from monocytes

Answer 47

97-C. Microglial cells arise from monocytes. They are phagocytes of the CNS and are also called
rod cells, gitterzellen, histiocytes, and macrocytes.