W1D1 - Neuro - Cn Iii, Iv And Vi

Front 1

What are the nuclei associated with the oculomotor nerves?

Back 1

Oculomotor nucleus - in midbrain and
accessory oculomotor nucleus (Edinger-Westphal nucleus) - preganglionic parasympathetics

Front 2

What nuclei are associated witht he trochlear nerve?

Back 2

trochlear nucleus dorsal to MLF

Front 3

What nuclei are associated with the abducens nerve?

Back 3

abducent nucleus

Front 4

What type of fibers are present in CN III, IV, VI and XII

Back 4

somatic motor fibers

Front 5

What muscles of the eye are found in the common tendinous ring?

Back 5

the 3 rectus muscles

Front 6

What CN are found within the common tendinous ring?

Back 6

oculomotor N (sup and inf. branch) and Abducent nerve and optic nerve

Front 7

what two muscles are just ou tof the common tendinous ring

Back 7

the levator palpebrae superiororis and the superior oblique

Front 8

Somatic efferents fom the oculomotor nucles innervate the (inferior division of CN III)

Back 8

medial rectus - ipsilateral
inferior rectus - ipsilateral
inferior oblique - ipsilateral

Front 9

Somatic efferents form the oculomotor nucleus innervate the (sup. division of CN III)

Back 9

superior rectus - contralateral
levator palpebrae superioris - ipsilateral and contralateral

Front 10

So - all CN III, IV, and VI are purely motor nerves?

Back 10

yes - well - kinda - there are always propriocepthive fibers, subconsciously need to know where you're eye is.

Front 11

What is the ciliary ganglion for then if the oculmotor nucles is purely motor?

Back 11

for parasymp fibers - ciliary ganglion found o nt he inferior branch - thus if you knock it out you lose parasymp as well

Front 12

if you knock ou the sup. brach of the oculomotor nerve will you lose parasymp innervation?

Back 12

no

Front 13

Preganglionic parasympathetics from the accessory oculomotor nucelus (Edinger-westphal nucleus) travel in the inferior dividsion of CN ___ to innervated the ______ _______.

Back 13

III, ciliary ganglion

Front 14

POstganglionic parasympathetic (from accessory oculomotor nucleus) are conveyed to targets via short ciliary nerves from teh ciliary ganglion - what are the targets?

Back 14

Ciliarus muscle (accomodation
pupillary sphincter (constricts pupil)

Front 15

Where is the Edinger west-phal nucleus found and where does it receive afferent form?What about it's efferents?

Back 15

posterolateral to the oculomotor nucleus
receives afferents from
cerbral cortex (for accomodation)
superiro colliculus (visual realy ) - tectospinal ex
Vestibular fibers from the MLF
Efferents:
to oculomotor nucleus - control of vertical eye movements

Front 16

What segment of the mid brain is the oculomotor nucleus found?

Back 16

in rostral midbrain by periaqueductal gray - when nerve leaves it enters the interpeduncular fossa

Front 17

What symptoms are seen when you lesion the oculomotor nerve? could appear because of an uncal herniation - where inflammation occurs and pushes uncus to the midbrain and pinches oculmotor nerve.

Back 17

ptosis - drooping of eyelid - paralysis of levator paralebrae superioris (smooth muscle) - sup. tarsal muscle will hold it open a bit though
lateral strabismus -pupil drifts laterally, lack of medial rectus
dilated pupil - no parasymp form sphinctor pupillae
loss of accommodation (edinger westphal nucleus)
loss of convergence - no medial recuts

Front 18

In Horner Syndrome do you lose the symp. or parasymp?

Back 18

symp - have ptosis, pupils will constrict not dilate

Front 19

What is the only cranial nerve to orginate on the posterior aspect of the brainstem?

Back 19

trochlear

Front 20

Where is the trochelar nerve found and where does it go?

Back 20

Found in CAUDAL midbrain
trochelar nucleus dorsal to teh MLF somatic efferent fibers travel posteriorly around the periaqueductal gray, decussate above teh cerebral aqueduct and travel to the contralateral superiro oblique muscle

Front 21

What would lesion of the left superior oblifque muscle look like?

Back 21

Eye would be laterally rotated and that patient would tilt their head toward the affected eye or contralateral nucleus - the eye ABducts and laterally rotates.

Front 22

What muscle does the abducent nerve innervate?

Back 22

ipsilateral lateral rectus muscle

Front 23

Neurons in teh abducent nucleus are activated in conjugate horizontal eye movements by activating the ipsilateral abducent nucleus and the contralateral _________ nucleus using projetios from the reticular formaiton (PPRF and the MLF)

Back 23

oculmotor

Front 24

Wehre is the abducent nucleus found in teh brainstem?

Back 24

Pontine tegmentum

Front 25

If you lesion the abducens nerve what do you get?

Back 25

medial strabismus - see double, rotate neck so that the object is seen clearly.

Front 26

Wehre does the PPRF primarily receive input from?

Back 26

the frotnal eye feild of cerebral cortex -

Front 27

How does the vestibuloocular reflex work?

Back 27

The paramedian pontine, reticular formation sends a signal is used in such a way that to get lateral gaze, the abducens nucleus is activated and the ipsilateral nerve activates and moves the lateral rectus muslce while the contralateral innervates the oculomotor nerve (via te MLF) and contracts the medial rectus muscle, thus pulling both eyes in teh same direction (yolking) - you can consciously move these as well

Front 28

What are the 7 extraocular muscles?

Back 28

Levator Palpebrae superioris - moves eyelid
Rectus muscles - superiro, inferior, medial, lateral
oblique muscles - sueprior inferior

Front 29

T/F the Axis of the orbit and Axis of the eyeball are in the same alignment.

Back 29

false, the axis of the orbit it 23 degree off of the axis of the eyeball - what makes us need the oblique muscles

Front 30

What three mvts. does the eyemake?

Back 30

rotation, vertical, horizonatl

Front 31

What muscles offset the movement of the rectus muscles?

Back 31

sup. oblique - works to offset lateral roation adn adduction of inf. rectus - depresses, ABducts and rotates medially
inf. oblique - works to offest medial roation and adduction of sup rectus -elevates, ABducts, and rotates laterally

Front 32

If you want to test the muscle what do you do?

Back 32

ISOLATE each function - so put the pupil in on the same axis line as the muscle
ex: to test for inf. oblique - look medially and upward

Front 33

What nerve. is associated with meningeal dura?

Back 33

trochlear and oculomotor

Front 34

What artery when calcifies can compress CN in the cavernous sinus?

Back 34

internal carotid artery

Front 35

Where does the trochlear nerve exit inot the eye socket?

Back 35

via the superior orbital fissure