Cranial Nerve Lecture Flashcards
sensory innervation of anterior 2/3 of tongue
lingual n. (br. of V3)
taste sensation of anterior 2/3 of tongue
chorda tympani n.
general sensation and taste innervation of posterior 1/3 of tongue
glossopharyngeal n. (CN IX)
CN VII somatic motor component
enters internal auditory meatus –> facial canal of temporal bone –> emerges from stylomastoid foramen
innervates facial muscles + stylohyoid, posterior belly of digastric, stapedius
CN VII parasympathetic component
- intermediate n. –> greater petrosal n. (to pterygopalatine ganglion, glands in eye, nose, palate)
- intermediate n. –> chorda tympani (to submandibular ganglion, sublingual and submandibular salivary glands in oral cavity)
CN VII special sensory component
taste fibers return from anterior 2/3 of tongue via piggybacking lingual n. (V3)
travels back through petrotympanic fissure w/ chorda tympani
encounter geniculate ganglion and return to CNS
CN V somatic sensory component
from trigeminal ganglion
V1 –> ophthalmic division
V2 –> maxillary division
V3 –> mandibular division
CN V somatic motor component
V3 (mandibular division) –>
4 m. of mastication
4 accessory n. of mastication
CN IX somatic motor component
thru jugular foramen to stylopharyngeus m.
CN IX somatic sensory component
thru jugular foramen to back of pharynx (gag reflex)
CN IX visceral sensory component
thru juglar foramen to carotid body/carotid sinus
CN IX special sensory component
thru jugular foreman to posterior 1/3 of tongue
taste and general sensory
CN IX visceral motor component
thru jugular foramen –> tympanic canaliculus “tympanic n.” –> forms plexus in middle ear –> emerges from middle ear as LESSER PETROSAL N. …
thru foramen ovale –> synapses on OTIC ganglion –> postganglionic fibers of lesser petrosal n. piggyback on AURICULOTEMPORAL n. (V3) –> jump off to supply PAROTID gland
CN III somatic motor component
oculomotor nucleus –> orbit –> split to sup/inf divisions –> supply 5 of 7 extraocular m.
superior rectus inferior rectus medial rectus inferior oblique levator palpebrae superioris
CN III visceral motor component
accessory oculomotor nucleus –> orbit –> inferior division CN III –> ciliary ganglion –> supply ciliary m. and sphincter pupillae
CN X visceral motor component
jugular foramen --> to glands and smooth muscle in... larynx pharynx esophagus abd viscera
–> to HEART
CN X somatic motor component
jugular foramen –> to…
pharyngeal constrictors
laryngeal m.
palatal m.
CN X special sensory component
jugular foramen –> to epiglottis (taste buds)
CN X somatic sensory component
jugular foramen –> to…
ear/canal
LARYNX (via superior/recurrent laryngeal n.)
dura
CN I
olfactory n.
special sensory only.
does NOT originate in brain stem.
originates in nose.
olfactory axons –> cribriform plate –> synapse on olfactory bulb of olfactory tract
olfactory tract
extension of the brain.
covered by meninges.
CN II
optic n. (extension of brain, covered by meninges)
light stim retina –> APs travel down optic n. –> some cross at optic chiasm, others don’t –> travel down “optic TRACT” –> occipital lobe for interpretation by visual cortex
optic n. vs optic tract
globe –> chiasm = optic n.
posterior to chiasm = optic tract
axons of retinal ganglion cells make up the
optic n.
CN IV
trochlear n.
somatic motor only.
devoted to one m. in eye (superior oblique m.)
CN VI
abducent n.
somatic motor only.
devoted to one m. in eye
(lateral rectus m. –> moves eye LATERALLY)
CN IV and CN VI are _____ motor only
SOMATIC motor only.
CN IIII
CN IV
CN VI
CN V(V1)
all enter thru …
superior orbital fissure
between greater and lesser wings of sphenoid bone
CN XI
spinal accessory n. (imposter, does NOT arise from brain stem)
somatic motor to SCM and trapezius.
fibers from spinal nuclei –> foramen magnum –> U-turn out through jugular foramen –> to SCM and trapezius
CN XII
hypoglossal n.
somatic motor only to tongue.
rootlets emerge from groove between pyramids/olive of medulla oblongata –> exits skull through hypoglossal canal –> innervates…
genioglossus
hyoglossus
stylglossus
palatoglossus m. innervation
CN X
genioglossus m. originates from
genial tubercles
CN VIII
2 nerves?
vestibulochoclear n.
enters internal acoustic meatus and splits into 2 divisions, both special sensory.
vestibular division –> balance
cochlear division –> hearing
CN VIII
path of vestibular division
enter internal acoustic meatus –> anterior toward cochlea for hearing
CN VIII
path of cochlear division
enter internal acoustic meatus –> back toward semicircular canals for balance
eye movement via oculomotor n. vs abducent n.
oculomotor n. –> most actions of eye
abducent n. –> specifically abduction (lateral movement of eye)
postganglionic fibers of greater petrosal n. to the ORBIT piggyback on ____ n.
postganglionic fibers of greater petrosal n. to the orbit piggyback on V1 and V2 n.
postganglionic fibers of greater petrosal n. to the PALATE AND NOSE piggyback on ____ n.
postganglionic fibers of greater petrosal n. to the PALATE AND NOSE piggyback on V2 n.
From where does the intermediate n. originate?
superior salivatory nucleus
Path of intermediate n. to glands of eye
intermediate n. --> internal acoustic meatus --> facial canal --> genu --> fwd direction, "greater petrosal n." --> crosses foramen lacerum --> vidian canal --> pterygopalatine fossa --> in orbit, piggybacks on V1 and V2 --> synapses on pterygopalatine ganglion
Path of intermediate n. to hard and soft palate
intermediate n. --> internal acoustic meatus --> facial canal --> genu --> fwd direction, "GREATER PETROSAL N." --> crosses foramen lacerum --> vidian canal --> pterygopalatine fossa --> piggyback on V2 --> V2 synapses on pterygopalatine ganglion--> postganglionic fibers go to nose, or through palatine canal to hard and soft palate
Path of intermediate n. to salivary glands
intermediate n. --> internal acoustic meatus --> facial canal --> genu --> path thru temporal bone, "CHORDA TYMPANI N." --> middle ear --> petrotympanic fissure --> submandibular ganglion in oral cavity --> post ganglionic fibers to salivary glands
vidian canal
from foramen lacerum in the middle cranial fossa to the pterygopalatine fossa
V1 dermatome
(ophthalmic division)
nasal cavity
paranasal sinuses
meninges
V2 dermatome
(maxillary division)
nasal cavity paranasal sinuses meninges hard/soft palate maxillary teeth/oral mucosa
greater petrosal n. vs. lesser petrosal n.
greater petrosal n. –> piggybacks w/ CN VIII to EYES/NOSE/PALATE
lesser petrosal n. –> piggybacks w/ CN IX to PAROTID gland
