Lecture 9: Cranial Nerves Flashcards
cranial nerves consist of:
- ___ ___ fibers that originate in the nuclei of the brainstem (LMNs)
- ___ ___ fibers that originate in the peripheral ganglia (trigeminal ganglia)
efferent motor; afferent sensory
the corticobulbar pathway ___ at the level of the CN nuclei
crosses over / decussates
CN V
trigeminal nerve
when a nerve is a mixed nerve, it has both ___ and ___ functions
motor; sensory
the trigeminal nerve is a mixed nerve; its motor and sensory roots attach at the ___
pons
the trigeminal nerve’s sensory pathway terminates in the ___
trigeminal sensory nucleus (outside and away from its cell body in trigeminal ganglia)
muscles closing jaw : masseter, temporalis, medial pterygoid :: muscles opening jaw : 1. ___ 2. ___ 3. ___
- lateral pterygoid
- anterior belly of diagastric
- mylohyoid
re: trigeminal nerve motor innervation
the tensor veli palatini tenses the velum, whereas the tensor tympani tenses the ___
tympanic membrane
re: trigeminal nerve motor innervation
name of the nerve providing sensation for the forehead, eyes, and nose
opthamalic nerve
re: trigeminal nerve sensory innervation
name of the nerve providing sensation for the upper lip mucosa, maxilla, upper teeth, cheeks, palate, and maxillary sinus
maxillary nerve
re: trigeminal nerve sensory innervation
name of the nerve providing sensation for the anterior 67% of tongue, mandible, lower teeth, lower lip, part of the cheek, and part of the external ear
mandibular nerve
re: trigeminal nerve sensory innervation
name of the nerve that supports the following functions:
mastication, articulation, hyolaryngeal elevation, tensing / closure of the soft palate, sensation to the face, teeth, gums, and anterior 67% of the tongue
trigeminal nerve / CN V
re: trigeminal nerve / CN V
unilateral UMN damage : no significant motor deficits :: unilateral LMN damage : 1. ___ 2. ___ 3. ___
- mandible deviates toward side of paralysis / paresis during opening
- muscle hypotonia and atrophy
- impaired hyolaryngeal elevation
re: trigeminal nerve / CN V
[choose] ___ (UMN / LMN) damage:
hypertonia, slow movements, restricted jaw opening / closing, reduced hyolaryngeal elevation
bilateral UMN
re: trigeminal nerve / CN V
[choose] ___ (UMN / LMN) damage:
hypotonia, significantly impaired jaw opening / closing, significantly impaired hyolaryngeal elevation
bilateral LMN
in trigeminal nerve ___ testing, the clinician lightly strokes above the eyebrows, the upper lip and central cheek, and between the lower lip and the chin
which three branches are stimulated?
sensory;
opthalamic, maxillary, and mandibular, respectively
CN VII
facial nerve
the facial nerve is a ___ nerve; its motor and sensory roots attach at the pons
mixed
the facial nerve’s sensory pathway terminates in the ___ for taste and the ___ for touch
nucleus of the tracts solitaries; spinal nucleus of the trigeminal nerve
in the facial canal, the greater superficial petrosal, lesser petrosal, and external petrosal meet at the ___
geniculate ganglion
CN VII monitors muscles of ___; it also innervates the latysma, stylohyoid, stapedius, posterior belly of the digastric, and glands (3)
facial expression
re: facial nerve motor innervation
name of the nerve sensory to taste (floor of mouth, hard and soft palates) and touch (external ear, auditory meatus)
facial nerve / CN VII
re: facial nerve sensory innervation
name of the nerve that supports the following functions:
movements of facial expressions, hyolaryngeal elevation, saliva and tear production, and taste at the front of the tongue
facial nerve / CN VII
___ testing of the ___ nerve includes: looking at facial symmetry, forehead wrinkle, tight eye closure, smile, and maintained resistance of lips and puffed cheeks
motor; facial
re: facial nerve / CN VII
[choose] (unilateral / bilateral) UMN damage : spastic paralysis of the whole face :: (unilateral / bilateral) UMN damage : contralateral lower face weakness
bilateral; unilateral
___ testing of the ___ nerve includes: testing taste (salty, sour, bitter, sweet) on each side of the tongue
sensory; facial
CN IX
glossopharyngeal nerve
the glossopharyngeal nerve is a mixed nerve; it emerges from the ___, with motor portions originating in the nucleus ambiguus and sensory components in the nucleus solitarius
medulla
name of the nerve that supports the following functions:
elevation of larynx and pharynx during swallowing, sensory innervation of the tongue and soft palate - including gag reflex
glossopharyngeal nerve / CN IX
motor and sensory testing of the glossopharyngeal nerve includes testing for ___
gag reflex
CN X
vagus nerve
CN XI
spinal accessory nerve
CN XII
hypoglossal nerve
the hypoglossal nerve is a ___-only nerve; it originates from the hypoglossal nucleus in the ___
motor; medulla
the hypoglossal nerve innervates intrinsic muscles of the tongue and innervates these three extrinsic muscles of the tongue: 1. ___ 2. ___ 3. ___
- genioglossus
- hyoglossus
- styloglossus
re: hypoglossal nerve motor innervation
name of the nerve that supports the following functions:
innervates muscles of the tongue involved in articulation, innervates oral stage swallowing muscles, innervates one pharyngeal stage swallowing muscle
hypoglossal nerve / CN XII
name of the nerve that conducts these motor testing protocols:
observing tongue at rest, protrude tongue, push tongue against inside of cheek, rapid alteration of tongue movements
hypoglossal nerve / CN XII
in hypoglossal nerve motor testing, if the patient pushes their tongue weakly against the left cheek then the weakness is on the ___ side
right, the side that pushes
in hypoglossal nerve motor testing, if the patient pushes their tongue weakly against the right cheek then the weakness is on the ___ side
left, the side that pushes
re: hypoglossal nerve / CN XII
unilateral UMN damage : ___ tongue weakness :: unilateral LMN damage: ___ tongue weakness
contralateral; ipsilateral
most of the extrinsic muscles of the tongue : bilaterally innervated :: ___ : contralaterally innervated
re: hypoglossal nerve / CN XII
genioglossus - the only one that receives contralateral innervation
bilateral UMN and bilateral LMN damage will result in weakness on ___ sides
re: hypoglossal nerve / CN XIi
both
name of the type of damage most often presenting with reduced range of motion and slow movements in patients with hypoglossus nerve (CN XII) damage
bilateral UMN
basic facts of CN XI, the spinal accessory nerve
motor only, consists of cranial roots (innervate palatal muscles) and spinal root (innervate the sternocleidomastoid and trapezius muscles)
name of the nerve whose function is to help turn, tilt, and thrust head forward
spinal accessory nerve / CN XI
name of the most complex cranial nerve
vagus nerve / CN X
basic facts of CN X, the vagus nerve
contains laryngeal and pharyngeal branches; main functions include voice production and swallowing; sensory innervation responsible for cough reflex and detection of residue after swallow; motor testing includes gag reflex paired with production of “ah”
true or false: most cranial nerves receive bilateral LMN innervation
false; most CNs receive bilateral UMN innervation
