9- Abnormal And Normal Binocular Vision Flashcards Preview

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Flashcards in 9- Abnormal And Normal Binocular Vision Deck (64):
1

What is normal binocular vision?

Both eyes used simultaneously for both retinal images of a target contribute to the final perception

2

Binocular vision requires the working together of what 2 systems?

Motor and sensory

3

What is the sensorimotor unit of the eye?

Light hits the retina, producing chemical and physical changes at the photoreceptors, impulses are transmitted to the CNA and we become aware of visual stimulation

4

What can affect sensory processing?

Any condition that prevents the integrator of the images from the 2 eyes

Ex. Amblyopia, uncorrected refractive error, eccentric fixation, disease

5

What is the motor process involved in?

Properly aligning the eyes at different distances and in difference gazes

6

T/F abnormalities n the sensory processing affects the motor?

True

7

What is included in teh spectrum of motor abnormalities

Disease
Deviations
Nystagmus
Vergence anomalies

8

Voluntary eye movements

You willed the eye movement

9

Involuntary eye movement

Occurs without awareness

10

What is a saccadic movement?

When the image over quickly across the retina with no apparent movement

11

What is the action of a muscle due to?

Direction of its pull around the axes

12

Primary action of a muscle is

It's major effect on teh position of the eye when the muscle contracts while the head is in primary position

13

Secondary and tertiary actions of a muscle are

Additional effect a muscle has on the position of the eye

14

The eye can move about ____ degrees but after ____ degrees the head turns

50, 20

15

Tangential point

Point at the cente of the muscle or tenon that first touches the globe

16

Arc of contact

Formed between the tangential point and the center of insertion of the muscle on the sclera

(Changes in length as the muscle contracts)

17

Muscle plane

Direction of pull of the muscle and determines the axis the muscle will move around

18

Visual axis passes from ____ to ___

Fovea to point of fixation

19

T/F the visual axis of both eyes intersect at fixation?

True

20

The globe rotates on this axes

Axes of Fick

21

The X axis has this movement

Vertical (up and down)

22

The y axis makes this movement

Torsional rotations like a wheel

23

The z axis does this movement

Horizontal (left and right)

24

What are 4 rectus muscles

Superior
Inferior
Medial
Lateral

25

What are the 2 oblique muscles

Superior
Inferior

26

What is the imaginary line that joins the rectus muscles

Spiral of tillaux

27

What is the spiral of tillaux important for?

Surgery

28

The medial rectus is this far from the limbus

5.5 mm

29

The superior rectus is this far from the limbus

7.7 mm

30

The lateral rectus is this far from the limbus

6.9 mm

31

The inferior rectus is this far from the limbus

6.5 mm

32

All rectus muscels arise from this

Annulus of Zinn

33

Medial rectus allows this motion

Moves eye to nose
ADDucts

34

MR is innervated by this

CN3

35

LR allows this movement

Moves eye away from nose
ABDucts

36

LR is innervated by

CN6

37

The medial and lateral walls of the eye are at what angle to each other?

45 degrees

38

The orbital axis is what angle of the medial and lateral walls

23 degrees

39

Where does the orbital axis run from

The apex to the opening of the orbit

40

N primary gaze with the angle of the orbital axis

23 degrees

41

What is the primary action of the SR

Elevate eye

42

What is the secondary action of the SR

Intortion

43

What is the tertiary action of the SR

ADDuction

44

SR is innervated by

CN3

45

The SR forms this angle with the visual axis

23 degrees

46

When the glob is abducted 23 degrees the SR is only a(n) _______

Elevator

47

When the glob is adducted 67 degrees the SR has only this action

Intortor

48

The primary action of the IR is

Move eye down

49

The secondary action of the IR is

Extortion

50

IR is innervated by

CN3

51

The IR forms this angle with the visual axis

23 degrees

52

When the globe is abducted 23 degrees the IR acts only as a

Depressor

53

When the globe is adducted 67 degrees the IR is only a

Extortor

54

The 2 oblique muscles insert behind the equator at this angle with the visual axis

51 degrees

55

What is the primary action of the SO

Intortion

56

What is the secondary action of the SO

Depression

57

What is the tertiary action of the SO

Abduction

58

SO is innervated by

CN 4

59

The SO passes through this

Trochlea

60

The primary action of the IO is

Extortion

61

The secondary action of the IO is

Elevation

62

The tertiary action of the IO is

Abduction

63

IO is innervated by

CN 3

64

The IO forms this angle with the visual axis

51 degrees