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Flashcards in Motor innervation Deck (61)
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1

what is affected in a CN 3 nucleus lesion

-ipsilateral MR, IR, IO
-ipsilateral sphincter (dilated pupil),
-cb muscle (lack of acc),
-contra/ipsi SR
-bilateral ptosis

2

what happens if lesion when follows of the superior+ posterior cerebral arteries around the cerebral peduncles

contralateral body weakness if lesion is close to the cerebral peduncles

3

what does cn4 follow

superior cerebellar and posterior cerebral arteries around the cerebral peduncle

4

inferior branch of cn3

io, ir, mr, parasympathetic, pupils-sphincter

5

lagopthalmos

obicularis cannot close eye properly --> dryness of cornea --> blindness usually with a cn 7 palsy

6

external ophthalmoplegia affected muscles

any or all eoms can be affected

7

cn6 fascicle location

within pons--> corticospinal tract (contra-weakness)

8

cn6 in cav sin

-within the cav sin near ica
-sympathetic fibers leave the ica + travel with the cn6 before splitting to cn3 or cn4
-first nerve involved with ica aneurysm
-horner's usually occurs in the cav sin due to all the signs

9

where does the cn4 travel through (last step)

travels through the superior orbital fissure above the CTR outside the muscle cone

10

what is the CN3 most frequently affected by

posterior communicating artery aneurysm

11

what does the SR nuclei innervate

contralateral superior rectus

12

what does cn6 nucleus contain and what do they do

internuclear neurons that travel in the MLF to the contralateral MR nucleus

13

cn4 fascicle location

posterior
below the inferior colliculus

14

why are you relatively extorted in primary gaze

-head tilt will force intorsion
-head turn will force the bad eye to abduct so the rectus muscles control up and down movements
-head is tilted downwards is the objects are more in line with the hyper eye

15

CN3 fascicle pathway

-passes through ipsilateral superior cerebellar peduncle (ipsi ataxia)
-through red nucleus (contra tremor)
-through cerebral peduncle (CST- contra weakness)
-passes through posterior cerebral artery + superior cerebellar artery
-follows the posterior communicating artery

16

what curves around the cn6 nucleus

facial nucleus

17

CN3 fascicle pathway innervention

-ipsilateral involvement of everything (MR, IR, IO, SR, levator, sphincter, CB)
-contra eye is normal

18

procerus

(pulls eyebrows down + medially)

19

cn 6 clinical correlate- sharp bend over the petrous ridge

susceptible to compression and stretching injuries, particularly with increased ICP

20

superior branch of cn3

sr, levator

21

if lesion above sof and ctr

so palsy
numbness of forehead (cn5)

22

trochlear nerve nucleus location

midbrain at the level of the inferior colliculus
-anterior to cerebral aqueduct
-dorsal to MLF
-caudal to cn3 nucleus

23

orbicularis

closes eyelids

24

what cranial nerves are involved in sensory for EOMS

2,5

25

cn6 lesion

gaze palsy innervation to LR to contralateral MR

26

what does the edinger westphal nucleus innervate

iris, sphincter (miosis), cb (acc, cb contracts, parasympathetic)

27

where wall does the cn4 enter

wall of cav sin

28

cn 6 palsy - what deviation from primary position

esotropic deviation- greater at distance

29

levator innervates

bilaterally

30

the parasympathetic fibers are spared in

spared in ischemic lesion due to vasculature surrounding the nerve

first thing to go involved in compressive lesions, including an aneurysm or tumor