neuroanatomy 3rd Comprehensive Examination 51 - 97 Flashcards
neuroanatomy 3rd Comprehensive Examination 51 - 97
- 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
D. The mandibular nerve (CN V-3) exits the skull through the foramen ovale; it is not found
in the cavernous sinus
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
52-B. The temporal pole is supplied by the anterior temporal artery, which is a branch of the
middle cerebral artery.
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
53-E. Ventral horn neurons develop in the basal plate of the mantle layer of the neural tube.
- 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
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.
- 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
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.
- 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
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.
- 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
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).
- 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
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.
- 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
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.
- 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
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.
- 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
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.
- 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
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).
- 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
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.
- 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
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).
- 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
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.
- 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
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).
- 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
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.
- 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)
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).
- 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
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.
- 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
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.
- 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
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.
- 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
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.
- 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
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.
- 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
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.