Cranial Nerves Flashcards
Which CNs are purely sensory
CNI, II, VIII
Which CNs are purely motor
CNIII, IV, VI, XI, XII
Which CNs are mixed nerves
CN V, VII, IX, X
Which motor column is most medial?
somatic motor
What is the order of motor column from medial to lateral
somatic, brachial, visceral
What is the order of sensory column from medial to lateral
visceral, somatic, special sensory
which CN nuclei are in the somatic motor column
CNIII, IV, VI, XII
which CN nuclei are in the brachial motor column
trigem and facial in pons
glossopharyngeal and vagus in medulla
accessory in the spinal cord
which muscles does CNV supply?
muscles of mastication
tensor tympani
tensor veli palatini
(T for T)
which muscles supply the muscles of the pharynx and larynx
Vagus for all pharynx and larynx muscles except for stylopharygeus, supplied by the glossopharyngeal
What is the name of nucleus enclosing both CNX and CNIX
nucleus ambiguus behind the inferior olive
What are the nuclei for visceral efferents
Edinger-Westfal nucleus for CNIII in midbrain
superior salivatory nucleus for VII in pons
inferior salivatory nucleus for IX in medulla
dorsal motor nucleus of X in medulla
the nucleus __________ is responsible for visceral afferent, which has inputs from CN ____, ____, and _____ . The visceral afferents have ______ and _______ functions
nucleus solitarius
VII, IX, X
taste
autonomic
Which nerve in the visceral afferent nucleus does not have autonomic function?
VII
Nucleus Solitarius extends from ________ to ________. The rostral portion is called ______, receiving inputs from ______ and ______. The caudal portion is called ________, which is mainly responsible for control of ________ function
pons nucleus gracilis gustatory nucleus taste buds palate visceral sensory division cardiovascular
Which nerves are included in the somatic sensory nucleus?
V, VII, IX, X
Meningioma can damage the olfactory nerve, how is the sense of smell affected?
anosmia, but also get sudden episodes of hallucinating smell, typically a smell of burning rubber
What is the most common cause of anosmia?
common cold
Where do the axons from olfactory bulb project to?
gustatory nucleus and insula cortex
Oculomotor nerve innervates four of the six extraocular muscles. Trochlear nerve innervates _________ and abducent innervates the _______. All three nerves exit together in the __________, along with the ______ branch of ______
superior oblique lateral rectus superior orbital fissure opthalmic trigeminal nerve
Which nerve exiting the superior orbital fissure is the most susceptible to injury? Why?
CNVI, because it has a long way to travel
what somatic motor function does CNIII have?
somatic motor for 4/6 extra-ocular muscles
elevates eyelid via levator palpebrae superioris
what PNS function does the ocularmotor nerve have
constriction of the pupil
focussing of the ciliary muscle
Are the PNS and somatic motor functions of CNIII segregated at brainstem?
Yes, they arise from different nuclei, but travel together through the SOF
why do cranial nerves often get affected together when there is a disease
CNs often exit in groups
which nerves exit from the auditory canal
facial and vestibulocochlear
which nerves exit from the jugular foramen
vagus and accessory
what are the three reflexes used for testing brainstem function
pupillary light reflex
blink reflex
gag reflex
what the pupillary light reflex assess?
the function of the midbrain
what is the efferent and afferent nerve for pupillary light reflex
afferent via optic nerve at the retina
efferent via ocularmotor tot he iris
where are the autonomic fibres of CNIII from?
Edinger-Westfal nucleus
a common viral cause of cranial nerve damage is?
Herpes Zoster (Shingles) on CNV. Virus lies dormant in trigem ganglion and can reactivate when the immune system is down
Trigeminal is mainly a ______ nerve, supplying the ________ function for the face, but it also has _______ motor fibres, innervating muscles of _________ and also the _______ in the inner ear
sensory somatic sensory brachial mastication tensor tympani
T/F Trigem supplies the sensory function of the brain tissue only
False, it also supplies the meninges
Trigem has nuclei that run from midbrain to spinal cord. What are the four nuclei?
mesencephalic
chief sensory
spinal trigeminal nucleus
motor nucleus
Pain sensation of trigem is located in the ________, proprioception is in __________, and everything else goes to _________
spinal trigeminal
mesencephalic
chief sensory
which division of trigem does the trigem motor nerve travel with?
mandibular V3
What does the corneal blink reflex test for?
pons function
Sensory input of corneal reflex is mediated by ________ of ________, which synapse onto interneurons ________, and excite efferent neurons of _______, and then the eys blink
opthalmic division
trigeminal nerve
bilaterally
facial nerve (on both sides)
(so that blinking occurs on both eyes when stimulating only one)
Facial nerve is predominantly a ______ nerve, supplying the ______ of the face. However it also has ________, ________, and ________ functions
brachial motor muscles PNS efferent visceral sensory somatic sensory
Which muscles does the facial nerve innervate in the middle ear? What is it important for?
stapedius
dampening sound
digastric muscle is supplied by which nerves?
facial and trigem
How does Bell’s Palsy occur?
damage to the lower motor neurons of CNVII
Facial nerve travels from the brainstem through the _________, first giving a branch called ________. It then gives motor supply to ________ and also ________ branch for taste in the _______ of the tongue. Finally, it gives a posterior motor branch called ________ and also 5 anterior motor branches forming _______ at the parotid gland
internal acoustic meatus greater petrosal stapedius chorda tympani anterior 2/3 posterior auricular pes anserinus
What is the function of greater petrosal branch?
PNS to the eye for lacrimation
Does the facial nerve supply the parotid gland?
no, it just passes through the substance of parotid
Ocularis oris is supplied by which branch of facial nerve?
temporal
Acoustic neuroma is characterised by ________ and ______. Because CNVIII travels with ______ through the ________, there also be loss of _______. Additionally, the lesion may also press on ______ to cause _______
gradual hearing loss dizziness CNVII internal acoustic meatus taste CNV facial pain
Glossopharyngeal supplies the visceral efferent for ______ on the ______ of the tongue. It is the primary sensory nerve for _______ and _______. It also supplies the PNS function to ______ and motor function to ________, which is responsible for ________
taste posterior 1/3 pharynx middle ear parotid gland stylopharyngeus palate elevation
CNIX exits via ________ and it follows _________ to reach the _________ and tongue
jugular foramen
stylopharyngeus
oropharynx
Which muscles does the vagus supply
muscles of the soft palate, pharynx, larynx, upper oesophagus and palatoglossus
Gag reflex is used to assess the function of __________. It receives sensory input from _______ and motor out from _______
medulla
glossopharyngeal
vagus
What are the symptoms of spinal accessory nerve damage?
flaccid paralysis, muscle wasting and atrophy of sternomastoid and upper part of trapezius
where does CNXI arise from? How does it enter and exit the cranium?
upper 5-6 of cervial spinal cord
via foramen magnum, and exit via jugular foramen with vagus
What movements is CNXI responsible for
Shoulder shrug and head turning
If you damage your left CNXI, which way can’t you turn?
cannot turn to the right (the opposite side)
What happens when you damage CNXII
tongue deviation to the damaged side and atrophy
T/F CNXII deficit is usually congenital
True if the damage is isolated to only CNXII. Because other nerves travel with CNXII, there are usually several CN deficits occurring at the same time
where does the CNXII exit?
hypoglossal foramen
