1
Q
A
2
Q
imaginary coronal plane through the center of the globe
A
Listing plane
3
Q
axes upon which the globe may rotate
A
Axes of fick
4
Q
X-axis of fick is responsible for what movement and actions?
A
Vertical movement
5
Q
Elevation and depression
A
6
Q
Y-axis of fick is responsible for what movement and actions?
A
Clockwise/counterclockwise
7
Q
Intorsion and extorsion
A
8
Q
Z-axis of fick is responsible for what movement and actions?
A
Horizontal
9
Q
Abduction and adduction
A
10
Q
Movement of single eye around X and Z axes
A
Duction movements
11
Q
Movement of both eyes around X and Z axes
A
Version movements
12
Q
The point at the center of the muscle or tendon that first touches the globe?
A
Tangential point
13
Q
arc formed between tangential point and center of insertion of the muscle on the sclera
A
Arc of contact
14
Q
describes the direction of pull and determines the axis that the muscle moves around when it contracts
A
Muscle plane
15
Q
How many EOMs are there? What are they?
A
Six -lateral rectus -medial rectus -superior rectus -inferior rectus -superior oblique -inferior oblique
16
Q
Imaginary line joining the insertions of the four Recti muscles
A
Spiral of tillaux
17
Q
Starting at medial rectus, each rectus muscle is located ___________ (in mm) from the limbus
A
further away
18
Q
MR insertion from the limbus
A
5.5 mm
19
Q
IR insertion from the limbus
A
6.5 mm
20
Q
LR insertion from the limbus
A
6.9 mm
21
Q
Superior rectus insertion from the limbus
A
7.7 mm
22
Q
__________ rectus muscles move around the Z axis
A
Horizontal
23
Q
__________ rectus muscles move around the x axis
A
Vertical
24
Q
All rectus muscles arise from the _______________
A
Annulus of Zinn
25
Medial and lateral walls lie at _______ of each other
45º
26
Orbital axis is at ______ of the medial and lateral wall
27
Visual axis is at _______º of the orbital axis
23º
28
Medial rectus action
adduction
29
MR innervation
CN III
30
Which rectus muscle is close to the ethmoid sinus and can be damaged during surgery or after a trauma?
Medial rectus muscle
31
lateral rectus action
abduction
32
Lateral rectus innervation
CN VI
33
Primary, secondary and tertiary action of superior rectus muscle
Primary: Elevation
Secondary: Intorsion
Tertiary: Adduction
34
Superior rectus innervation
Oculomotor nerve (CN III)
35
When globe is abducted 23º→ visual and orbital axes coincide → Sacts as a pure _____________
Elevator
36
When globe is adducted 67º → angle between visual and orbital Visual axis ADDducted axes is 90o → superior rectus acts as pure _________
Intorter
37
Primary, secondary and tertiary action of inferior rectus muscle
Primary: depression
Secondary: extorsion
Tertiary: Adduction
38
Inferior rectus innervation
Oculomotor nerve (CN III)
39
When globe is abducted 23º → visual and orbital axes coincide → IR acts as a pure ____________
Depressor
40
When globe is adducted 67º → angle between visual and orbital Visual axis ADDducted axes is 90º → inferior rectus acts as pure ___________
Extorter
41
Each oblique muscle inserts behind the ___________
Equator
42
Primary, secondary and tertiary action of superior oblique muscle
Primary: Intorsion
Secondary: depression
Tertiary: Abduction
43
Superior oblique innervation
Trochlear nerve (CN IV)
44
When the globe is abducted 39º → visual axis and superior oblique make an angle of 90º with each other → superior oblique acts as a pure __________
Intorter
45
When the globe is adducted to 51º → visual axis and 51º insertion coincide → SO acts as a pure _______________
Depressor
46
Primary, secondary and tertiary action of inferior oblique muscle
Primary: extorsion
Secondary: elevation
Tertiary: Abduction
47
Inferior oblique innervation
Oculomotor nerve (CN III)
48
How does the inferior oblique course in comparison to the inferior rectus muscle?
Courses inferiorly to the inferior rectus muscle
49
When the globe is abducted 39º → visual axis and superior oblique make an angle of 90º with each other → inferior oblique acts as a pure _____________
Extorter
50
When the globe is adducted to 51º → visual axis and 51º insertion coincide → IO acts as a pure _________
Elevator
51
How many diagnostic positions of gaze are there?
9, (6 cardinal, 2 midline vertical, 1 primary)
52
gaze (one of cardinal positions) where effect of a muscle action is best observed
Field of action
53
Depression by the SO is best seen in the ___________ position
Adduction
54
Any weakness of the SO can be seen as a failure of _____________ in adduction
Depression
55
EOM motility test assesses ability to perform _____________ eye movements
Conjugate
56
With EOM testing, _____________ is typically performed first, then ___________ is performed if restrictions occur on ___________
Versions (binocular)
Ductions (monocular)
Versions
57
How is EOM under/overaction graded?
Zero = normal
Underaction = minus
Overaction = plus
58
Forced Duction Test: Resistance → mechanical restriction of muscle __________ forced duction test
Positive
59
Forced Duction Test: Movement → paretic muscle → __________ forced duction test
Negative
60
Pair of muscles in the same eye that move the eye in opposite directions
Agonist-antagonist muscles
61
medial rectus OD is the antagonist of the __________________
lateral rectus OD
62
Muscles in the same eye that move the eye in the same direction
Synergistic muscles
63
Example of synergist muscles: inferior oblique OS and ____________________ OS
Superior rectus OS
64
pair of muscles, one in each eye, that produce conjugate eye movements (move eyes in same direction)
Yoked muscles
65
RIO is the yoked muscle of the _______
LSR
66
LMR is the yoked muscle of the _______
RLR
67
simultaneous and conjugate eye movements or rotations of both eyes in the same direction (ex: EOM testing)
Version
68
disconjugate eye movement where the eyes (visual axes) rotate in opposite directions (ex: NPC testing)
Vergence
69
Sherrington law of reciprocal innervation: increased innervation to one muscle is accompanied by a reciprocal decreased _______________________________
Innervation to its antagonist in the same eye
70
Example of Sherrington Law: increased innervation to LMR (causing contraction, adduct OS) makes the _______________ relax
left lateral rectus
71
Describe Herring Law of Equal Innervation
During conjugate movements, equal and simultaneous innervations flow to yoked muscles
72
When there is a muscle palsy, the _______ muscle in the other eye will overact
Yoke
73
_________________ muscles and ____________ muscles adjust their tones to prevent vertical deviations or torsional movements from the line of sight during horizontal versions
Vertical rectus muscles and oblique muscles
74
during vertical and oblique versions, ________________________ muscles stabilize the line of sight and prevent horizontal movements
Horizontal rectus
75
Primary deviation: when the ____________ eye is fixating
Unaffected
76
Secondary deviation: _________________ eye is fixating
paretic/restricted
77
Look at example of primary and secondary deviation on slide 58 and 59
78
Name antagonists and synergists for EOMs on slide 60
79
During a _____________ movement, the image moves quickly across the retina with no apparent movement.
Saccadic
80
_________________ controls - include the cranial nerves responsible for eye movements (III, IV, VI) and the muscles they innervate (all the rectus and oblique muscles).
Infra nuclear
81
____________ controls - cranial nuclei
Nuclear
82
______________ controls: this is the higher order sensory and motor system that plans and controls the eye movements.
Supranuclear
83
What are the two Supranuclear eye movements?
Versions and Vergences
84
Fast conjugate eye movements for refixation
saccades
85
Saccades - ________ - ________º per second
400-700º
86
Saccades are a type of ____________ movement because eyes move in the same direction
Version
87
Are version movements slow or fast?
Fast
88
When are Saccades well developed?
1 year of age
89
Saccades bring image to the __________
Fovea
90
Saccades are faster than ____________ and __________
Pursuits and vergences
91
Are saccades voluntary or involuntary?
both, but usually voluntary
92
What is an example of reflex Saccades?
REM during sleep
93
Pursuing following eye movements
Pursuits
94
Pursuit conjugate movements keep the fovea on a ________________ target
Slowly moving
95
Latency of pursuits is __________ than Saccades
Shorter
96
___________ are used for voluntary eye movements to track a moving object
Pursuits
97
If target velocity increases, pursuits show what movement? And why?
Jerky movement since it has a velocity of only 30-60º per second
98
Movement to stabilize a retinal image during brief head movement/rotation
Vestibulo-ocular reflex
99
How is the latency of VOR?
Very fast (5ms)
100
Does vestibulo-ocular reflex require visual stimuli?
No
101
VOR produces eye movemt of equal magnitude to head movement in ____________ direction
Opposite
102
Vestibular damage can cause horizontal _____________
Nystagmus
103
Supranuclear gaze palsy is seen when voluntary eye movements (_________________) are impaired but involuntary _________ is preserved
Saccades/pursuits
104
Normal VOR via Doll's Head Maneuver will result in eye movements that are __________ and ________ to the head movement
Equal and opposite
105
Doll's Head Maneuver is contraindicated in what patients?
Those with possible cervical spine injuries
Block 15
flashcards
Decks in class (15)
# Cards
-
Intro To CL63
-
Post Seg: Diagnostic Approach To Retinal Disease51
-
Ant Seg: uvea/sclera Anatomy Review49
-
Ant Seg: Embryology20
-
Ant Seg: Orbital Anatomy Review12
-
Ant Seg: Evalutions Of Orbital Disorders26
-
Post Seg: Diagnostic Approach To Retinal Disease6
-
Post-seg: Retinal Physiology And Psychophysics32
-
CL: Contacts Len Care, Solutions, Insertions, And Removals45
-
CL: Soft Lens 1: Sphere/Asphere101
-
BVM: Introduction13
-
BVM: EOMs105
-
BVM: Alignment129
-
CL: Contact Lens Care9
-
Post- Seg: Diabetic Retinopathy56
