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Flashcards in Ocular motility Deck (28)
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1

Ocular motility - muscles and innervation

1. Superior rectus (CN III)
2. Lateral rectus (CN VI)
3. Inferior oblique (CN III)
4. Inferior rectus (CN III)
5. Medial rectus (CN III)
6. Superior oblique (CN IV)

2

Superior rectus action

Elevate the abducted eye

3

Lateral rectus action

Abduct the eye

4

inferior oblique action

Elevate the adducted eye

5

Medial rectus action

Adduct the eye

6

superior oblique action

Depress the adducted eye

7

trochlea of superior oblique is

a pulley-like structure in the eye. The tendon of the superior oblique muscle passes through it.

8

to test function of each muscle, ask patient to

follow a path from 1ry position

9

left superior oblique and inferior oblique tested with patient ...

looking right

10

right superior oblique and inferior oblique tested with patient ...

looking left

11

MC affected CN by tuberculosis

CN VI is the most commonly affected VI in immunocompetent people with tuberculosis

12

Abducens nerve (CN VI) damage/palsy - physical finding

Medially directed eye that cannot abduct
-adducted at rest
-cannot be abducted
- diplopia occurs on lateral gaze to the side of the affected eye

13

Trochlear nerve (CN IV) damage/pulsy - eye at rest

Eye moves upward (hypertropia)

14

Trochlear nerve (CN IV) damage/pulsy - increased elevation with

1. adduction (contralateral gaze)
2. head tilting to the affected side

15

Trochlear nerve (CN IV) damage/pulsy - decreased elevation with

1. abduction
2. head tilting to the opposite direction

16

Trochlear nerve (CN IV) damage/pulsy - problems when

going down stairs, reading newspaper (requires looking down and inward)

17

Trochlear nerve (CN IV) damage/pulsy - solution

may present with compensatory head tilt in the opposite direction

18

Oculomotor nerve (CN III) has both ....... components (and area)

1. motor (central of the nerve)
2. parasympathetic (peripheral of the nerve)

19

Motor output of CN III to ocular muscles is affected primarily by ..... due to .....

vascular disease (diabetes mellitus: glucose --> sorbitol) due to decreased diffusion of oxygen and nutrients to the interior fibers from compromises vasculature that resides on outside of nerve

20

Motor output of CN III to ocular muscles - signs of damage

1. ptosis
2. down and out gaze

21

Parasympathetic output of CN III - causes of damage (mechanism)(not examples)

fibers on the periphery are 1st affected by compression

22

Parasympathetic output of CN III - examples of compression

1. uncal herniation
2. Posterior communicating artery aneurysm

23

The uncus is (area)

an anterior extremity of the Parahippocampal gyrus

24

Parasympathetic output of CN III - signs of damage

1. diminished or absent papillary light reflex
2. Blown pupil (mydriasis)
3. often with down and out gaze

25

CN VI palsy - diplopia occurs

On lateral gaze to the side of the affected eye

26

CN IV palsy - diplopia is most pronounced when the patients

Look downward with the affected eye adducted

27

CN VI palsy - diplopia occurs

On lateral gaze to the side of the affected eye

28

Central vs peripheral area of CN III

central: Motor
peripheral: Parasympathetics