Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anatomy > CN III, IV, VI > Flashcards

CN III, IV, VI Flashcards

1
Q

what do CN III, IV, VI innervate

A

somatic motor to extraoccular eye muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

all extraoccular eye muscles insert where ?

A

sclera of the eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the function of the superior oblique m. ? inferior oblique m.?

A

superior oblique - internal rotation

inferior oblique - external rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what level of the brainstem would you find the occulomotor nucleus

A

rostral midbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what level of the brainstem would you find the trochlear nucleus

A

caudal midbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what level of the brainstem would you find the abducens nucleus

A

caudal pons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the autonomic preganglionic cell body located beside the occulomotor nucleus , and what muscles does it innervate ?

A

Edinger-Westphal of PNS

  • pupillary sphincter
  • ciliary muscle for accomodation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

which muscles does CN III have control over, and of those mm. which one is innervated contralaterally

A

Superior rectus, medial rectus, inferior rectus, inferior oblique
-superior rectus contralaterally the rest are ipsilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what would be the autonomic result of an injury to the occulomotor and edingerwestphal nuclei ?

A

mydriasis - ipsilateral dilated pupil
pupil does not constrict in response to light
can not accomodate for close vision
-happens cuz pupillary constrictor and ciliary mm are dysfunctional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

any injury to the occulomotor nucleus would result in ?

A

ipsilateral damage to extraoccular mm. innervated by CN III

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a lateral strabismus and what causes it ?

A

where an eye deviates laterally, caused by lesion to occulomotor nucleus thus making medial rectus dysfunctional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does CN IV innervate ?

A

contralateral superior oblique m.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which CN nucleus would course through the red nucleus

A

occulomotor nucleus cuz its in rostral medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the results of a lesion in the CN IV nucleus

A

-much less noticeable than CN III injury (very mild deficit)
-diplopia when reading or going downstairs
-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the only CN on the dorsal of the brainstem surface

A

IV trochlea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does CN VI innervate

A

ipsilateral lateral rectus

17
Q

what is the result of lesion to CN VI

A

ipsilateral eye damage causing medial strabismus

18
Q

what is a medail labismus and what causes it

A

eye is deviated medially b/c of a lesion in the CN VI which innervates lateral rectus

19
Q

what is the MLF and what does it do

A

Medial longitudinal fasiculus

-coordinates head and specifically eye nuclei for lateral gazing

20
Q

internuclear opthalmoplegia is what ?

A

paralysis of the eye due to damage b/w nuclei

-removes input from occulomotor nucleus

21
Q

what are the 4 sets of neurons involved in the pupillary light reflex

A

1 - retinal gangli sends afferent to pretectal nuclei
2 - pretectal nuclei to Edingerwestall nucleus
3- EDW nucleus sends preganglionic PNS fibers to ciliary ganglion
4 - synapse at ciliary ganglion sending postganglionic fibers to contract pupillary sphincter and cilliary m.

22
Q

accomodation for near vision is controlled by what ?

A

PNS

23
Q

what do the short ciliary nerves do ?

A

postganglionic PNS fibers to tell pupillary sphincter and ciliary mm to contract

24
Q

in response to accomodation the cisual axis of both eyes tend to converge or diverge ?

A

converge

25
Q

what muscles of the eye are activated by the SNS

A

pupilary dilator, levator palpebrae superioris

26
Q

what are the 3 conjugate movements of the eye

A

scanning - 1 target to another in saccades
tracking - smooth pursuit
compensation - gaze held on object during head movement (vestibulocular reflex)

27
Q

what is a saccade

A

quick simultaneous movement of eyes

28
Q

what is responsible for horizontal saccades

A

paramedian pontine reticular formation (PPRF)

29
Q

what is responsible for upward saccades

A

rostral MLF in midbrain

30
Q

what is responsible for downward saccades

A

midbrain

31
Q

what saccade is voluntary

A

left

Anatomy (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions