Flashcards in Cranial Nerves: Motor Deck (48):
What is CN III?
Where is the location of neuron cell bodies of CN III?
Upper Midbrain--oculomotor nucleus
What is the passage of CN III through the skull?
Superior Orbital Fissure --Sphenoid bone
Where does the oculomotor nerve emerge?
near median plane at junction of midbrain and pons-->cavernous sinus--> superior orbital fissure
Where does the rectus m. originate?
common tendinous ring---oculomotor nerve ends up here
Levator palpebrae innervated by:
Superior Rectus m. innervated by:
Inferior Rectus m innnervated by:
Medial Rectus m. innervated by:
Inferior Oblique m. innervated by:
Oculomotor nerve palsy
causes ptosis = eyelid droop due to paralysis of levator palpebrae muscle
paralysis of levator palpebrae~ eyelid droop
What is the resting position of the eye?
Down and out when oculomotor isn't working---when superior oblique and lateral rectus m. aren't working
CC: pupil is fixed and dialated
Oculomotor III is out
A cavernous sinus injury causes damage to what cranial nerve?
An aneurysm of posterior cerebral or superior cerebellar artery causes damage to which cranial nerve?
Function of trochlear nerve?
somatic motor--eye movement
Location of neuron cell body of Trochlear nerve
Lower midbrain: trochlear nucleus
Where does trochlear nerve pass through skull
Superior Oribital fissure: sphenoid bone
Where does the trochlear nerve emerge from midbrain?
from dorsal aspect of midbrain
What is the only nerve to emerge dorsally from the skull?
What structure does the trochlear nerve innervate?
Superior oblique muscle
What happens when the Trochlear nerve is injured?
Can't look down when eye is adducted which is called diplopia
What causes injury to trochlear nerve?
cavernous sinus injury
What is CN VI
What is the fnx f CN VI?
somatic eye movement
Location of NCB of Abducent?
How does the Abducent nerve exit the skull?
sphenoid bone--superior orbital fissure
What is the route of the Abducent nerve?
emerges near medial plane at jnx of pons and medulla--> through the cavernous sinus and superior orbital fissure--> through common tendinous ring
What structure does the Abducent nerve innervate?
Lateral rectus muscles
What causes horizontal diplopia (double vision)
Abducent nerve (VI)
What causes impaired eye abduction?
Abducent nerve damage VI
Which way does the eye turn when the Abducent nerve is damaged?
Eye turns medially~ medial rectus muscle out)
What causes injury to Abducent nerve VI?
Cavernous sinus injury and fracture to base of skull
What nerve is CN XI?
Where is the location of neuronal cell bodies of CN XI?
Spinal Cord: anterior horn of cervicle region
Where does the Accessory nerve pass through the skull?
Rootlets (intermediate in position of exit from sp cd) via foramen magnum
--exits via jugular foramen
What structures are innervated by the Accessory nerve?
SCM and and Trapezius
What kind of injury would cause damage to accessory XI
Special part of CN XI
spinal root represents CN XI in it's entirety, cranial roots emerge from medulla but those are part of CN X
What nerve is CN XII?
The location of the NCB of CN XII?
Where does the CN XII pass through the skull?
Occipital bone--hypoglossal canal
What is the route of CN XII?
Emerges from sides of medulla anterior to olives--> passes through hypoglossal canal--> curves forward near angle of mandible superior to ansa cervicalis to enter tongue
What structures does hypoglossal XII innervate?
All intrinsic tongue muscles
All extrinsic tongue muslces except Palatoglossus (CN X)
What happens to tongue when there is a peripheral lesion in Hypoglossal CN XII?
tongue deviates towards side of injury
--lick your wounds