Ductions, Versions, and Vergences Flashcards

1
Q

What are ductions

A

The movements of ONE eye

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

Ductions can be explained by

A

Rotations around one or more axes

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

Fick’s axes (3)

A

X axis (horizontal, transverse)

  • Divides eye into anterior and posterior halves
  • Supraductions and infraductions

Y axis (sagittal, visual)

  • Divides eye into medial and lateral parts
  • Incycloduction (intorsion) and excycloduction (extorsion)
Z axis (vertical)
-Adduction and abduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

If the course of the muscle is parallel to an axis…

A

Then no rotation around that axis can occur

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

If the course of the muscle is perpendicular to an axis…

A

Then the only rotation for that muscle is around that axis

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

Actions from primary gaze of the medial rectus

A

Perpendicular to the Z/vertical axis. So it is able to adduct the eye.

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

Actions from primary gaze of the lateral rectus

A

Perpendicular to the Z/vertical axis. So it is able to abduct the eye.

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

Actions from the primary gaze of the superior rectus

A
  1. Supraduct
  2. intortion
  3. adduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Actions from the primary gaze of the inferior rectus

A
  1. Infraduct
  2. extortion
  3. adduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Actions from the primary gaze of the superior oblique

A
  1. Intorsion
  2. Infraduct
  3. abduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Actions from the primary gaze of the inferior oblique

A
  1. Extortion
  2. Supraduct
  3. abduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cardinal position of gaze

A

6 Positions of gaze isolates each EOM

Clinically useful to determine if each EOM is functioning properly.

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

If exactly 23 degrees from the primary position,

A

The superior and inferior rectus are perpendicular to the horizontal axis and will supra duct (SR) and infra duct (IR) the eye

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

If exactly 51-55 degrees from primary position

A

The superior oblique will infraduct and the inferior oblique will supraduct

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

Agonist/antagonist pairs

A

Lateral rectus/medial rectus
superior rectus/inferior rectus
superior oblique/inferior oblique

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

When an agonist contracts (Stimulated), its antagonist

A

relaxes (inhibited)

17
Q

Synergist

A

A muscle that works in concert with another muscle to generate movement.

18
Q

Versions

A

Movement of both eyes in the same direction

19
Q

Dextroversion

A

Both eyes move to the right

20
Q

Dextroelevation

A

Both eyes move up and to the right

21
Q

Dextrodepression

A

both eyes move down and to the right

22
Q

Levoversion

A

Both eyes move to the right

23
Q

Levoelevation

A

Both eyes move up and to the left

24
Q

Levodepression

A

Both eyes move down and to the left

25
Elevation
Both eyes move up
26
Depression
Both eyes move down
27
Hering's law of equal innervation
Pair of muscles receives equal and simultaneous excitatory or inhibitory signals (versions)
28
Vergences
Movement of both eyes in opposite directions
29
What occurs during convergence
Each eye is adducted to fixate at near target
30
What occurs during divergence
Each eye is abducted to fixate at distance target