Cranial Nerves Final Examination ACTUAL
EXAM 2026/2027 | Comprehensive
Neuroanatomy | Verified Q&A | Pass
Guaranteed - A+ Graded
SECTION 1: CRANIAL NERVES I–VI (OLFACTORY THROUGH ABDUCENS) – 40 Questions
Q1: A 45-year-old woman with multiple sclerosis reports double vision that worsens when looking to the
right. On exam, the right eye fails to adduct past midline, with nystagmus of the abducting left eye.
Convergence is intact. Where is the lesion?
A. Right oculomotor nerve (CN III) – would cause ptosis, mydriasis, down-and-out gaze, not isolated
adduction deficit
B. Right abducens nerve (CN VI) – would cause failure of abduction, not adduction
C. Right medial longitudinal fasciculus (MLF) – internuclear ophthalmoplegia (INO), CN VI nucleus
connected to contralateral CN III via MLF [CORRECT]
D. Right trochlear nerve (CN IV) – would cause vertical diplopia and head tilt, not horizontal gaze deficit
Correct Answer: C
Rationale: This is right INO (MLF lesion), classic for demyelination in MS or lacunar stroke in older
patients. The MLF coordinates conjugate horizontal gaze between CN VI nucleus and contralateral CN III
subnucleus. Convergence sparing (intact medial rectus function for near vision) differentiates INO from
CN III palsy. First Aid 2026, Ch. 5; Brainstem Pathways.
Q2: Which cranial nerve exits the skull through the cribriform plate?
A. Optic nerve (CN II) – exits via optic canal
B. Olfactory nerve (CN I) – sensory, passes through cribriform plate of ethmoid bone [CORRECT]
C. Oculomotor nerve (CN III) – exits via superior orbital fissure
D. Trochlear nerve (CN IV) – exits via superior orbital fissure
Correct Answer: B
Rationale: CN I (olfactory) consists of bipolar sensory neurons passing from olfactory epithelium through
cribriform plate foramina to olfactory bulb. Trauma causing anosmia and CSF rhinorrhea suggests
cribriform plate fracture. First Aid 2026, Ch. 5.
,Q3: A 62-year-old man with hypertension presents with sudden onset of ipsilateral facial pain and
contralateral body pain/temperature loss. He also has dysphagia and hoarseness. Which arterial
territory is most likely involved?
A. Anterior inferior cerebellar artery (AICA) – lateral pontine syndrome, CN V, VII, VIII affected
B. Posterior inferior cerebellar artery (PICA) – lateral medullary (Wallenberg) syndrome, affects CN IX, X,
spinothalamic tract [CORRECT]
C. Superior cerebellar artery (SCA) – affects cerebellum and midbrain
D. Anterior spinal artery – medial medullary syndrome
Correct Answer: B
Rationale: Lateral medullary (Wallenberg) syndrome from PICA occlusion causes: ipsilateral facial
pain/temperature loss (spinal trigeminal tract/nucleus), contralateral body pain/temperature loss
(spinothalamic tract), dysphagia/hoarseness (nucleus ambiguus – CN IX, X), vertigo, ataxia, Horner's
syndrome. First Aid 2026, Ch. 5; Vascular Syndromes.
Q4: Which cranial nerve is described as "motor to the muscles of mastication, sensory to the face, and
parasympathetic to the lacrimal and salivary glands"?
A. Facial nerve (CN VII) – motor to face, parasympathetic to glands, not mastication
B. Trigeminal nerve (CN V) – mixed (motor, sensory, parasympathetic via lesser petrosal nerve
connection) [CORRECT]
C. Glossopharyngeal nerve (CN IX) – mixed but not mastication
D. Vagus nerve (CN X) – not mastication or facial sensation
Correct Answer: B
Rationale: CN V (trigeminal) is the largest cranial nerve: motor to muscles of mastication (V3), sensory
to face (V1 ophthalmic, V2 maxillary, V3 mandibular), and parasympathetic fibers hitchhike via V1
(greater superficial petrosal → lacrimal) and V2/V3 connections. First Aid 2026, Ch. 5.
Q5: A patient presents with complete ptosis, "down and out" gaze, and mydriasis on the right. Which
structure is affected?
A. Right trochlear nerve (CN IV) – superior oblique only, vertical diplopia
B. Right abducens nerve (CN VI) – lateral rectus only, cannot abduct
C. Right oculomotor nerve (CN III) – motor to levator palpebrae, all extraocular muscles except LR/SO,
parasympathetic to pupil [CORRECT]
D. Right sympathetic chain – would cause partial ptosis (Müller muscle), miosis (Horner's), not "down
and out"
Correct Answer: C
Rationale: Complete CN III palsy affects: somatic motor (levator palpebrae → ptosis; all EOM except
LR/SO → "down and out"), parasympathetic (sphincter pupillae → mydriasis). "Down and out" because
unopposed action of LR (CN VI) and SO (CN IV). First Aid 2026, Ch. 5; Clinical Neuroanatomy.
Q6: Which nucleus gives rise to preganglionic parasympathetic fibers for pupillary constriction and
accommodation?
, A. Edinger-Westphal nucleus – located in midbrain, CN III, parasympathetic to ciliary ganglion [CORRECT]
B. Superior salivatory nucleus – CN VII, lacrimal/submandibular
C. Inferior salivatory nucleus – CN IX, parotid
D. Dorsal motor nucleus of vagus – CN X, thoracic/abdominal viscera
Correct Answer: A
Rationale: Edinger-Westphal nucleus (accessory oculomotor nucleus) contains preganglionic
parasympathetic neurons. Fibers travel with CN III to ciliary ganglion, postganglionic fibers to sphincter
pupillae (miosis) and ciliary muscle (accommodation). First Aid 2026, Ch. 5.
Q7: A 28-year-old man presents with anosmia after head trauma. Imaging shows a fracture through
which bone?
A. Temporal bone – affects CN VII, VIII
B. Ethmoid bone – cribriform plate fracture affects CN I [CORRECT]
C. Sphenoid bone – optic canal, cavernous sinus
D. Occipital bone – foramen magnum
Correct Answer: B
Rationale: The cribriform plate of the ethmoid bone is thin and easily fractured in facial trauma. This
damages olfactory nerve filaments causing anosmia and may tear meninges causing CSF rhinorrhea
(connection between nasal cavity and subarachnoid space). First Aid 2026, Ch. 5; Skull Base Anatomy.
Q8: Which cranial nerve exits the brainstem dorsally and decussates before innervating its target?
A. Oculomotor (CN III) – ventral exit
B. Trochlear (CN IV) – only cranial nerve to exit dorsally (caudal midbrain), decussates in superior
medullary velum [CORRECT]
C. Trigeminal (CN V) – ventral exit
D. Abducens (CN VI) – ventral exit
Correct Answer: B
Rationale: CN IV (trochlear) is unique: exits dorsally from caudal midbrain, decussates in superior
medullary velum, wraps around brainstem, passes through cavernous sinus, enters orbit via superior
orbital fissure to innervate superior oblique muscle. First Aid 2026, Ch. 5.
Q9: A patient has impaired downward and inward gaze of the left eye, with rightward head tilt. Which
nerve is affected?
A. Left oculomotor (CN III) – would affect most EOMs, ptosis, mydriasis
B. Left trochlear (CN IV) – superior oblique palsy, impaired depression when adducted, head tilt away
from lesion to compensate [CORRECT]
C. Left abducens (CN VI) – impaired abduction
D. Left trigeminal (CN V) – not EOM
Correct Answer: B
Rationale: CN IV palsy affects superior oblique (depresses eye when adducted, intorts). Patient has
EXAM 2026/2027 | Comprehensive
Neuroanatomy | Verified Q&A | Pass
Guaranteed - A+ Graded
SECTION 1: CRANIAL NERVES I–VI (OLFACTORY THROUGH ABDUCENS) – 40 Questions
Q1: A 45-year-old woman with multiple sclerosis reports double vision that worsens when looking to the
right. On exam, the right eye fails to adduct past midline, with nystagmus of the abducting left eye.
Convergence is intact. Where is the lesion?
A. Right oculomotor nerve (CN III) – would cause ptosis, mydriasis, down-and-out gaze, not isolated
adduction deficit
B. Right abducens nerve (CN VI) – would cause failure of abduction, not adduction
C. Right medial longitudinal fasciculus (MLF) – internuclear ophthalmoplegia (INO), CN VI nucleus
connected to contralateral CN III via MLF [CORRECT]
D. Right trochlear nerve (CN IV) – would cause vertical diplopia and head tilt, not horizontal gaze deficit
Correct Answer: C
Rationale: This is right INO (MLF lesion), classic for demyelination in MS or lacunar stroke in older
patients. The MLF coordinates conjugate horizontal gaze between CN VI nucleus and contralateral CN III
subnucleus. Convergence sparing (intact medial rectus function for near vision) differentiates INO from
CN III palsy. First Aid 2026, Ch. 5; Brainstem Pathways.
Q2: Which cranial nerve exits the skull through the cribriform plate?
A. Optic nerve (CN II) – exits via optic canal
B. Olfactory nerve (CN I) – sensory, passes through cribriform plate of ethmoid bone [CORRECT]
C. Oculomotor nerve (CN III) – exits via superior orbital fissure
D. Trochlear nerve (CN IV) – exits via superior orbital fissure
Correct Answer: B
Rationale: CN I (olfactory) consists of bipolar sensory neurons passing from olfactory epithelium through
cribriform plate foramina to olfactory bulb. Trauma causing anosmia and CSF rhinorrhea suggests
cribriform plate fracture. First Aid 2026, Ch. 5.
,Q3: A 62-year-old man with hypertension presents with sudden onset of ipsilateral facial pain and
contralateral body pain/temperature loss. He also has dysphagia and hoarseness. Which arterial
territory is most likely involved?
A. Anterior inferior cerebellar artery (AICA) – lateral pontine syndrome, CN V, VII, VIII affected
B. Posterior inferior cerebellar artery (PICA) – lateral medullary (Wallenberg) syndrome, affects CN IX, X,
spinothalamic tract [CORRECT]
C. Superior cerebellar artery (SCA) – affects cerebellum and midbrain
D. Anterior spinal artery – medial medullary syndrome
Correct Answer: B
Rationale: Lateral medullary (Wallenberg) syndrome from PICA occlusion causes: ipsilateral facial
pain/temperature loss (spinal trigeminal tract/nucleus), contralateral body pain/temperature loss
(spinothalamic tract), dysphagia/hoarseness (nucleus ambiguus – CN IX, X), vertigo, ataxia, Horner's
syndrome. First Aid 2026, Ch. 5; Vascular Syndromes.
Q4: Which cranial nerve is described as "motor to the muscles of mastication, sensory to the face, and
parasympathetic to the lacrimal and salivary glands"?
A. Facial nerve (CN VII) – motor to face, parasympathetic to glands, not mastication
B. Trigeminal nerve (CN V) – mixed (motor, sensory, parasympathetic via lesser petrosal nerve
connection) [CORRECT]
C. Glossopharyngeal nerve (CN IX) – mixed but not mastication
D. Vagus nerve (CN X) – not mastication or facial sensation
Correct Answer: B
Rationale: CN V (trigeminal) is the largest cranial nerve: motor to muscles of mastication (V3), sensory
to face (V1 ophthalmic, V2 maxillary, V3 mandibular), and parasympathetic fibers hitchhike via V1
(greater superficial petrosal → lacrimal) and V2/V3 connections. First Aid 2026, Ch. 5.
Q5: A patient presents with complete ptosis, "down and out" gaze, and mydriasis on the right. Which
structure is affected?
A. Right trochlear nerve (CN IV) – superior oblique only, vertical diplopia
B. Right abducens nerve (CN VI) – lateral rectus only, cannot abduct
C. Right oculomotor nerve (CN III) – motor to levator palpebrae, all extraocular muscles except LR/SO,
parasympathetic to pupil [CORRECT]
D. Right sympathetic chain – would cause partial ptosis (Müller muscle), miosis (Horner's), not "down
and out"
Correct Answer: C
Rationale: Complete CN III palsy affects: somatic motor (levator palpebrae → ptosis; all EOM except
LR/SO → "down and out"), parasympathetic (sphincter pupillae → mydriasis). "Down and out" because
unopposed action of LR (CN VI) and SO (CN IV). First Aid 2026, Ch. 5; Clinical Neuroanatomy.
Q6: Which nucleus gives rise to preganglionic parasympathetic fibers for pupillary constriction and
accommodation?
, A. Edinger-Westphal nucleus – located in midbrain, CN III, parasympathetic to ciliary ganglion [CORRECT]
B. Superior salivatory nucleus – CN VII, lacrimal/submandibular
C. Inferior salivatory nucleus – CN IX, parotid
D. Dorsal motor nucleus of vagus – CN X, thoracic/abdominal viscera
Correct Answer: A
Rationale: Edinger-Westphal nucleus (accessory oculomotor nucleus) contains preganglionic
parasympathetic neurons. Fibers travel with CN III to ciliary ganglion, postganglionic fibers to sphincter
pupillae (miosis) and ciliary muscle (accommodation). First Aid 2026, Ch. 5.
Q7: A 28-year-old man presents with anosmia after head trauma. Imaging shows a fracture through
which bone?
A. Temporal bone – affects CN VII, VIII
B. Ethmoid bone – cribriform plate fracture affects CN I [CORRECT]
C. Sphenoid bone – optic canal, cavernous sinus
D. Occipital bone – foramen magnum
Correct Answer: B
Rationale: The cribriform plate of the ethmoid bone is thin and easily fractured in facial trauma. This
damages olfactory nerve filaments causing anosmia and may tear meninges causing CSF rhinorrhea
(connection between nasal cavity and subarachnoid space). First Aid 2026, Ch. 5; Skull Base Anatomy.
Q8: Which cranial nerve exits the brainstem dorsally and decussates before innervating its target?
A. Oculomotor (CN III) – ventral exit
B. Trochlear (CN IV) – only cranial nerve to exit dorsally (caudal midbrain), decussates in superior
medullary velum [CORRECT]
C. Trigeminal (CN V) – ventral exit
D. Abducens (CN VI) – ventral exit
Correct Answer: B
Rationale: CN IV (trochlear) is unique: exits dorsally from caudal midbrain, decussates in superior
medullary velum, wraps around brainstem, passes through cavernous sinus, enters orbit via superior
orbital fissure to innervate superior oblique muscle. First Aid 2026, Ch. 5.
Q9: A patient has impaired downward and inward gaze of the left eye, with rightward head tilt. Which
nerve is affected?
A. Left oculomotor (CN III) – would affect most EOMs, ptosis, mydriasis
B. Left trochlear (CN IV) – superior oblique palsy, impaired depression when adducted, head tilt away
from lesion to compensate [CORRECT]
C. Left abducens (CN VI) – impaired abduction
D. Left trigeminal (CN V) – not EOM
Correct Answer: B
Rationale: CN IV palsy affects superior oblique (depresses eye when adducted, intorts). Patient has
