Cranial Nerves Flashcards
What is the modality of the trigeminal nucleus?
Sensory
What nucleus is responsible for taste?
Nucleus solitarius
What is CN VII?
Facial
What nerves exit the skull via the superior orbital fissure?
CN III, IV, V1, VI
What is CN I?
Olfactory
Where does CN VII & VIII exit the cranium?
Internal acoustic meatus
What is CN XI?
Spinal accessory
CN III runs between what two arteries?
Superior cerebellar and posterior cerebral arteries
What CN have nuclei in the medulla?
CN IX, X, XI, XII
What is CN is the Trigeminal nerve?
CN V
How does CN XI innervation of the sternocleidomastoid and trapezius differ?
CN XI is contralateral to the trapezius and ipsilateral to the SCM
What is the function of the medial longitudinal fasciculus?
The MLF provides a connection between the abducens nucleus and oculomotor nucleus. This allows for medial gaze.
What is CN VI?
Abducens
What CN is the Occulomotor nerve?
CN III
What nucleus wraps around the abducens nucleus?
Facial nucleus wraps around abducens nucleus
What nuclei play a role in the gag reflex?
Spinal nucleus of trigeminal (CN IX) & ambiguus (CN X)
What is CN IV?
Trochlear
What nucleus is responsible for pupil size and lens shape? What CN synapses at this nucleus?
Edinger-Westphal Nucleus, CN III
What is the modality of the ambiguus nucleus?
Motor & parasympathetic (CN X)
What CN is the Vestibulocochlear nerve?
CN VIII
Where is lateral gaze coordinated?
Paramedian pontine reticular formation (PPRF)
What is the only CN to have nuclei in all regions of the brainstem?
Trigeminal
Nuclei for what CN are found in the midbrain?
CN III, IV, V
What are the branches of the Trigeminal nerve?
V1 - Ophthalmic
V2 - Maxillary
V3 - Mandibular
What nucleus connects V1 and CN VII to induce involuntary eye blinking due to stimulation of the cornea?
Trigeminal nucleus
What CN are located in the Pons?
CN VI, VII, VIII
How does control of upper and lower facial muscles differ?
The facial nerve innervates both upper and lower facial muscles. The upper muscles have bilateral (ipsilateral and contralateral) control, while the lower muscles only have contralateral control.
Axons from the optic nerve synapse where before crossing over at the posterior commissure?
Pretectal nuclei
Where are the nuclei for the olfactory and optic nerves located?
Trick question. CN I & II do not have nuclei. The olfactory nerve connects directly with the temporal lobe. The optic nerve connects directly with the brainstem, thalamus, and hypothalamus.
What is CN II?
Optic
What CN is the hypoglossal nerve?
CN XII
What are the functions of CN III?
Eye movement, maintain open eyelid, pupil size, lens shape
What CN is the glossopharyngeal nerve?
CN IX
What is CN X?
Vagus
True/False. A lesion on the optic nerve leads to a deficit in the consensual pupillary light reflex in that eye.
False. The pupillary light reflex is a branch of CN III and would be functional despite a lesion on CN II. Only a consensual pupillary reflex and not a direct reflex would be present.
Motor CN nuclei are found where in the brainstem?
Medially
Sensory CN nuclei are found where in the brainstem?
Laterally
What nerve exits the foramen ovale?
CN V3
Where does the maxillary nerve exit the cranium?
Foramen rotundum
What structure exits the cranium via the foramen spinosum?
Middle meningeal artery
What nerves exit the skull via the jugular foramen?
CN IX, X, XI
Where does CN XII exit the skull? Where is this space located?
Hypoglossal canal, located lateral to the foramen magnum
What is the only CN to exit the skull via the foramen magnum?
CN XI
What CN controls most muscles of eye movement?
CN III - Occulomotor
The superior oblique muscle is controlled by what CN?
CN IV - Trochlear
What is the only muscle of eye movement innervated by the Abducens nerve?
Lateral rectus
Taste sensation to the tongue is provided by what nerve?
Anterior - CN VII (chorda tympani)
Root - CN IX
Motor innervation for most tongue muscles is from what nerve?
CN XII
What nerves provide general sensory innervation to the tongue?
Anterior - CN V3
Root - CN IX & X
