EOMs Flashcards

1
Q

What is the embryonic derivative of the EOMs?

A

Mesodermal origin

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

When do the EOMs begin developing

A

Week 3 of gestation

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

When are the EOMs fully formed

A

6 months, but continue to enlarge during remaining part of gestation

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

Microaantomy of EMOs

A

Striated muscles with actin and myosin

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

Eye movements are _______ and more __________ due to unique combination of white (fast) and red (slow) muscle fibers

A

Faster

Fatigue resistant

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

What are the two layers of the EOMS

A
  • orbital (superficially)

- globular (deeper)

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

What are the 4 rectus muscles

A

Inferior
Superior
Medial
Lateral

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

What are the two oblique muscles

A

Superior and inferior

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

What two muscles only have 1 action?

A

Medial and lateral rectus

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

Primary action of medial rectus

A

Auction

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

Primary action of lateral rectus

A

Abduction

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

Primary, secondary, and tertiary action of superior rectus

A

Elevation
Intorsion
Adduction

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

Primary, secondary, an tertiary actions of the inferior rectus

A

Depression
Extortion
Adduction

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

Primary, secondary, and tertiary actions of superior oblique

A

Intorsion
Depression
Abduction

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

Primary, secondary, and tertiary actions of inferior oblique

A

Extortion
Elevation
Abduction

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

What is the primary action for the obliques?

A

Torsions

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

Where do all 4 of the recti muscles originate?

A

Annulus of zinn or common tendinous ring

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

What structure is the annulus of zinn in?

A

Oculomotor foramen

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

What passes through the oculomotor foramen?

A
  • oculomotor nerve
  • optic nerve
  • ophthalmic artery
  • abducens nerve
  • nasociliary nerve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What EOM inserts closest to the limbus?

A

Medial rectus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the spiral of tillaux

A

The insertions of the EOMs relative to the limbus become further and further from the limbus going clockwise(OD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Order of spiral of tillaux

A

Medial rectus
Lateral rectus
Superior rectus
Inferior rectus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Origin of levator palpebrae superioris

A

Lesser wing of sphenoid bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Action of levator palpebrae superioris

A

Elevation of upper lid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Innervation of levator palpebrae superioris

A

CNIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How does the superior rectus run?

A

Passes beneath levator, above superior oblique on globe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Primary action of the superior rectus

A

Elevation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Origin of superior rectus

A

Annulus of zinn

29
Q

Innervation of superior rectus

A

Superior division of CNIII

30
Q

Blood supply to the superior rectus

A

Superior lateral muscular branch of ophthalmic artery

31
Q

What is the largest EOM?

A

Medial rectus

32
Q

Primary action of medial rectus

A

Adducts

33
Q

Origin of medial rectus

A

Annulus of zinn

34
Q

Blood supply of medial rectus

A

Inferior medial muscular branch of ophthalmic artery

35
Q

Primary action of inferior rectus

A

Depresses

36
Q

Innervation of inferior rectus

A

Inferior division of the CNIII

37
Q

Primary action of lateral rectus

A

Abducts

38
Q

Origin of lateral rectus

A

Superior and inferior annulus of zinn, and greater wing of sphenoid bone

39
Q

Innervation of lateral rectus

A

CN VI abducens

40
Q

Longest and thinnest EOM

A

Superior oblique

41
Q

Innervation of superior oblique

A

Trochlear

42
Q

Shortest EOM

A

Inferior oblique

43
Q

Origin of inferior oblique

A

Maxillary bone (only EOM to have its anatomical origin in the anterior orbit)

44
Q

What is the only EOM to have its anatomic origin in the anterior orbit

A

Inferior oblique

45
Q

What are check ligaments

A

Provide stop to excessive movement

46
Q

Eyes aligned around sagittal and horizontal plane, head erect, focus infinity

A

Primary gaze

47
Q

Rotation around a single Fick axis (levoversion; left gaze)

A

Secondary gaze

48
Q

Rotation around both horizontal and vertical axis (levodepression; or down or left)

A

Tertiary gaze

49
Q

X axis

A

Elevation/depression

50
Q

Y axis

A

Torsional movements

51
Q

Z axis

A

Abduction/abduction

52
Q

The plane passing through the center of roatation of the eye and contains the X and Z axes

A

Listings plane

53
Q

Movement involving one eye

A

Ductions

54
Q

Ductions movements

A

Abduction
Abduction
Supraduction
Infraduction

55
Q

Tested by occluding one eye and asking the patient to follow target in each direction of gaze

A

Ductions

56
Q

Conjugate movement of both eyes in the same direction

A

Versions

57
Q

Eight positions of gaze with version movements

A
  • infraversions (downward gaze)
  • supraversion (upward gaze)
  • dextroversion (right gaze)
  • levoversion (left gaze)
  • infralevoversion (downward left gaze)
  • infradextroversion (downward right gaze)
  • supralevoversion (upward left gaze)
  • supradextroversion (upward right gaze)
58
Q

Tested with both eyes open and asking the patient to follow a target in each direction of gaze

A

Versions

59
Q

Disjunctive movement of both eyes

A

Vergence

60
Q

Both eyes looking inward

A

Convergence

61
Q

Booth eyes looking outward

A

Divergence

62
Q

What EOMs are innervated by the superior division of CN III

A

Superior rectus

63
Q

What EOMs are innervated by the inferior division of CN III

A
  • medial rectus
  • inferior rectus
  • inferior oblique
64
Q

EOMs ar predominantly supplied by

A

Two muscular branches from the ophthalmic artery

65
Q

Largest vein in the orbit

A

Superior ophthalmic vein

66
Q

What is responsible for majority of venous drainage of the eye

A

Superior ophthalmic vein

67
Q

Receives blood from the muscular veins draining the SR and MR

A

Superior ophthalmic vein

68
Q

Receives blood from the muscular veins draining the MR, IR, IO, and IR

A

Inferior ophthalmic vein