Brainscape's Knowledge GenomeTM

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


See full index

Head and neck > Session 8- Extraocular eye muscles, actions and testing > Flashcards

Session 8- Extraocular eye muscles, actions and testing Flashcards

1
Q

what does binocular vision allow

A

wider field of vision and depth perception

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

what is conjugate eye movement

A

eyes need to coordinate and move together

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

what causes diplopia

A

misalignment of two visual axes image focuses on different area of each retina
-brain unable to fuse these see 2 separate images

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

what is diplopia

A

double vision

2 images seen can be displaced horizontal, vertical and diagonally

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

what are the for recti

A

superior
inferior
lateral
medial

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

what are the 2 obliques

A

superior

inferior

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

where do extra-ocular muscle attach

A

sclera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

where do extraocular muscles riginate

A

apex of orbit except inferior oblique which arises from the floor of orbital cavity anteriorly
-the 4 recti originate from a common tendinous ring

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

what innervates the extra ocular muscles

A

LR6SO4

Lateral rectus- 6- abducens
Superior oblique- 4 -Trochlear

all remaining occulolotor

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

why do some muscles attach at an oblique angle

A

the muscles run in line with the axis of orbit

-confers several actions of movement on globe for some of the extra ocular muscles

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

which muscles have a single action on the eye

A

Medial rectus and lateral rectus

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

what movement is moving the eye medially

A

adduction

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

what movement is moving the eye laterally

A

abduction

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

what muscles adducts the eye

A

medial rectus

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

what muscle abducts the eye

A

lateral rectus

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

what is the action of superior rectus if starting from primary resting gaze

A

elevate
slightly adducts
slightly intorts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

when is the superior rectus a more powerful elevator

A

when the eye is positioned laterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

where does superior rectus inserts

A

superior anteriolateral surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

where does IR attach

A

anteroinferior surface of globe

20
Q

action of IR

A

depress
slightly adducts
slightly extort

21
Q

when is IR a more powerful depressor

A

when the eye is positioned laterally

22
Q

where does SO attach

A

passes through trochlea inserts into superior-posterior aspect of globe

23
Q

SO action

A

intort

depress

24
Q

when is the SO a more powerful depressor

A

when eye is positioned medially

25
Q

where does IO attach

A

infero-posterior aspect of globe

26
Q

action of IO

A

extort
elevate
slightly abduct

27
Q

when is IO a more powerful elevator

A

when eye is positioned medially

28
Q

which extra-ocular muscles have an action in elevating the eyeball

A

superior rectus

inferior oblique

29
Q

which extra-ocular muscles have an action in depressing the eye ball

A

inferior rectus

superior oblique

30
Q

which extra ocular muscles are stronger elevators and depressors of th eyeball when the eye is adducted

A

inferior oblique

superior obliquw

31
Q

which extra-ocular muscles are stronger elevators and depressors of the eyeball when the eye is abducted oosition

A

superior and inferior rectus

32
Q

strabismus

A

common in children - exact cause not always known

in adults- acquired due to pathology or disease -myasthenia gravis/ nerves supplying the muscles

cranial nerves can be affected

  • vasculopathic
  • physical compression
  • raised intracranial pressure
33
Q

how do we isolate elevaton and depression actions of SR/IO and IR/SO

A

move starting postion of eye laterally or medially first then test elevation and depression

34
Q

what are the main elevators and depressors of the eye when the eyball is starting from the lateral position

A

recti muscles

superior - elevates
inferior- depreses

35
Q

what muscles are the main elevators and depressors of the eye when the eye is in the medial position

A

IO - elevates

SO- depresses

36
Q

what are the 2 qcquired causes of CN III palsy

A

vasculopathic lesions- pupil spared

compressive lesions -pupil involved

37
Q

which extra ocular muscles does the trochlear nerve innervate

A

superior oblique muscle

-intorts, abducts and depresses

38
Q

in what position is the eye held in a trochlear nerve lesion

A

extorted, slightly elevated and adducted

39
Q

how is the extortion of the eye compensated in a trochlear nerve palsy

A

head tilt- this is because the eye is extorted and slightly elevated

40
Q

what is the most likely cause for CN III, IV and VI

A

vasculopathic

41
Q

What is the difference between periorbital cellulitis and orbital cellulitis?

A

Periorbital cellulitis confined to tissues superficial to orbital septum and tarsal plates.
Orbital cellulitis - result of an infection affecting fat and muscles posterior to orbital
septum, within the orbit but not involving the globe.

42
Q

What are the three main types of conjunctivitis?

A

bacterial

viral

allergic

43
Q

What is age-related macular degeneration?

A

Most common cause of blindness in the
UK. Degeneration of the macula is the key feature with changes usually bilateral. Two
forms of macular degeneration are dry and wet

44
Q

What features will you see on the retina for central retinal artery occlusion?

A

Pale

retina, cherry red spot

45
Q

Which test do you use to check colour vision?

A

ishihara chart

46
Q

what is used to test visual acuoty

A

snellen chart

47
Q

What is orbital cellulitis

A

red and swollen right upper and lower
eyelids. On examination, he had reduced visual acuity, mild proptosis, painful and reduced
ocular movements.

(usually caused by upper respiratory tract infection from the sinuses)

Head and neck (19 decks)

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