Cranial Nerves Flashcards
What is the name of CN I ?
Olfactory nerve
What tract does the olfactory nerve have?
Afferent - sensory only
Ipsilateral
What is the function of the olfactory nerve?
Carries input from receptors in olfactory (smell) epithelium
What is the primary cortex of the olfactory nerve?
Inferior frontal lobe
Medial temporal lobe
What receptors does the olfactory nerve have?
Chemoreceptors
What tests are performed for the olfactory nerve?
Olfaction test
What is the name of CN II ?
Optic nerve
What is the tract of the optic nerve?
Afferent
Bilateral hemi-decussation
What is the function of the optic nerve?
Carries input from receptors in the eye
What is the primary cortex of the optic nerve?
Posterior occipital lobe
What are the receptors of the optic nerve?
Photoreceptors
rods/cones
What tests are done to test the optic nerve?
Pupillary reflex
Visual acuity
Astigmatism
What is the name of CN III ?
Oculomotor nerve
What is the tract of the oculomotor nerve?
Efferent
Afferent
Ipsilateral
What is the function of the oculomotor nerve?
Efferent - innervates skeletal muscles that move eyeball up, down, and medially, and raise upper eyelid; innervates smooth muscles that constrict pupil and alter lens shape for near & far vision
SR, IR, MR, IO
(LR6SO4)3
Pupil constrictor muscle
Ciliary muscle
Raise upper eyelid
Afferent - transmits information from receptors in muscles
What is the primary cortex of the oculomotor nerve?
Postcentral gyrus
What are the receptors of the oculomotor nerve?
Aff. - muscle spindles/tendon organs
What is the nucleus of the oculomotor nerve?
Midbrain
What are tests for the oculomotor nerve?
6 cardinal points
Extorsion
Ptosis
What is the name of CN IV ?
Trochlear nerve
What is the tract of the trochlear nerve?
Efferent
Afferent
Contralateral
What is the function of the trochlear nerve?
Efferent - innervates skeletal muscles that move the eyeball down and laterally
(LR6SO4)3 -> SO4 , superior oblique moves the eye inferior/medial
Afferent - Transmits information from receptors in muscles
What is the primary cortex of the trochlear nerve?
Postcentral gyrus
What are the receptors of the trochlear nerve?
Aff. - MS/TO
Where is the nucleus of the trochlear nerve found?
Midbrain
What are the tests for the trochlear nerve?
Intorsion
Where does the trochlear nerve originate?
Dorsal midbrain
What is the name of CN V ?
Trigeminal nerve
V1 - opthalamic
V2 - maxillary
V3 - mandibular
What tract does the trigeminal nerve have?
Efferent and Afferent
What tract is the CN V1?
Afferent only
What tract is CN V2 ?
Afferent only
What tract is CN V3?
Afferent + Efferent
What is the function of the trigeminal nerve?
Afferent; transmits information from receptors in skin; skeletal muscles of face, nose, mouth, teeth sockets (V1 and V2)
Efferent; innervates skeletal muscles used for chewing
Afferent V3; inferior face (V3)
What is the primary cortex of the trigeminal nerve?
Postcentral gyrus
What are the receptors of the trigeminal nerve?
Aff; general sensory, temp, touch, thermo, nocic
Eff; MS/TO
Where is the nucleus of the trigeminal nerve found?
Pons
What tests are performed for the trigeminal nerve?
3 divisional testing
Corneal reflex
What is not a function of the trigeminal nerve?
Taste
What is the name of CN VI ?
Abducens nerve
What is the tract of the abducens nerve?
Efferent
Afferent
Ipsilateral
What is the function of the abducens nerve?
Efferent; innervate muscles that move eyeball laterally (lateral rectus (LR6SO4)3
Afferent; transmits hearing and balance information from receptors in muscles
What is the primary cortex of the abducens nerve?
Postcentral gyrus
Where is the nucleus of the abducens nerve?
Pons
What are the receptors of the abducens nerve?
MS/TO
What is a test for the abducens nerve?
Extorsion
What is the name of CN VII ?
Facial nerve
What is the tract for the facial nerve?
Efferent
Afferent
Ipsilateral
What is the function of the facial nerve?
Efferent; innervates skeletal muscles of facial expression and swallowing; innervates nose, palate, and lacrimal and salivary glands
Afferent; transmits information from taste buds in front of tongue and mouth (anterior 2/3 of tongue)
What is the primary cortex of the facial nerve?
Postcentral gyrus for both aff. and eff.
What are the receptors for the facial nerve?
Aff; chemoreceptors
Eff; tendon organs (skeletal muscles)
Where is the nucleus for the facial nerve?
Pons
What are tests for the facial nerve?
Sensory: taste testing
Motor: facial expression
What CN are in charge of taste?
CN VII, IX, X
What is the name of CN VIII ?
Vestibulocochlear nerve
What is the tract of the vestibulocochlear nerve?
Afferent - sensory only
Ipsilateral
What is the function of the vestibulocochlear nerve?
Aff; transmits hearing and balance information from receptors in inner ear
What are the receptors of the vestibulocochlear nerve?
Hair cells
Vestibular and auditory information -> mechanoreceptors
Where is the nucleus of the vestibulocochlear nerve found?
Pons
What are tests for the vestibulocochlear nerve?
Vestibulo-ocular reflex
Screen hearing
Sound localization
Rinne test
Weber test
Where do we become consciously aware of balance?
Postcentral gyrus
What is a vestibular ocular reflex (VOR)?
Balance
What is the name of CN IX ?
Glossopharyngeal nerve
What tract is the glossopharyngeal nerve?
Efferent
Afferent
Ipsilateral
What is the function of the glossopharyngeal nerve?
Eff; innervates skeletal muscles involved in swallowing and parotid salivary gland
Tongue + pharynx. Involuntary, skeletal muscles
Aff; Transmits information from taste buds at back of tongue & receptors in auditory-tube skin;
also transmits information from carotid artery baroreceptors (BP receptors) and chemoreceptors that detect changes in blood gas levels
Taste (posterior 1/3) -> postcentral gyrus
What is the primary cortex of the glossopharyngeal nerve?
Postcentral gyrus
What are the receptors for the glossopharyngeal nerve?
Baroreceptors
Chemoreceptors
Where is the nucleus for the glossopharyngeal nerve?
Medulla oblongata
What are tests for the glossopharyngeal nerve?
Gag reflex
Uvular reflex
What is the name of CN X ?
Vagus nerve
What is the tract for the vagus nerve?
Efferent
Affterent
Ipsilateral
What is the function of the vagus nerve?
Eff; innervates skeletal muscles of pharynx and larynx and smooth muscle and glands of thorax and abdomen.
Motor to Involuntary swallowing. Cardiac. Dig. tract.
Aff; Tramsats information from receptors in thorax and abdomen. General sensory from abdominopelvic cavity, taste to posterior mouth.
What is the primary cortex for the vagus nerve?
Postcentral gyrus
What are the receptors of the vagus nerve?
Chemoreceptors?
Baroreceptors?
Where is the nucleus for the vagus nerve?
Medulla oblongata
What are tests for the vagus nerve?
Gag reflex
Uvular appearance
Uvular reflex
Voice hoarseness
Throat pain
Vocalization (ah)
Cough/swallow
What is the name of CN XI ?
Accessory nerve
What is the tract for the accessory nerve?
Efferent
Ipsilateral
Does the accessory nerve have an afferent tract?
Generally don’t see
What is the function of the accessory nerve?
Eff; innervates sternocleidomastoid and trapezius muscle in the neck
What is the primary cortex of the accessory nerve?
N/A since it’s motor only
What are the receptors for the accessory nerve?
Mechanoreceptors
MS/TO
>????
Where is the nucleus for the accessory nerve?
Medulla oblongata
What are tests for the accessory nerve?
Shoulder shrug
Shoulder symmetry/atrophy
MMT of SCM
SCM palpation
What is the name of CN XII ?
Hypoglossal nerve
What is the tract for the hypoglossal nerve?
Efferent
Ipsilateral
What is the function of the hypoglossal nerve?
Eff; innervates skeletal muscles of the tongue
What is the primary cortex of the hypoglossal nerve?
N/A since motor only
What are the receptors for the hypoglossal nerve?
Muscle spindles to cervial spinal nerves - skeletal muscle
Where is the nucleus for the hypoglossal nerve?
Medulla oblongata
What are tests for the hypoglossal nerve?
Speech articulation
Tongue movement
Tongue appearance
Where is the nucleus for CN I and II?
In sensory organ which gets sent down
What CNs have their nucleus in the midbrain?
CN III and IV
What CNs have their nucleus in the pons?
CN V, VI, VII, VIII
What CNs have their nucleus in the medulla oblongata?
CN IX, X, XI, XII
How to remember order of nucleus in CNs?
2
2 midbrain
4 pons
4 medulla oblongata
What does (LR6SO4)3 mean?
CN 3, 4, 6 move the eye
The lateral rectus is innervated by CN 6
The superior oblique is innervated by CN 4
CN 3 innervates everything else
Somatic vs Viscera (ANS)
Somatic is skeletal muscles and associated somatic tissue
ANS is the autonomic nervous system, involuntary movement
The primary cortex for somatosensory
postcentral gyrus
Where is the pre central gyrus?
Frontal lobe
Where is the post central gyrus?
Parietal lobe