Brainscape's Knowledge GenomeTM

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


See full index

272A > L15 EOMs > Flashcards

L15 EOMs Flashcards

1
Q

What is the fascial sheath aka orbital fascia?

A

Modified conjunctiva that forms the periosteum of the bones of the orbit. All structures that can be isolated in the orbit are covered by fascial sheath, except optic nerve. It is continuous with dura matter of optic nerve, and continuous with orbital septum

It surrounds all organs and muscles within orbit from fat and other stuff.

i.e. around rectus muscle and eyeball

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

The superior and inferior rectus, along with oblique muscles attach at an angle, and therefore have … actions

A

tertiary

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

Fascial sheath also forms the … capsule (is the same thing as)

A

Tenon’s capsule

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

What do the check ligaments do?

A

Prevents eye from going inwards

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

What is the Tenon’s capsule?
aka facia bulbi or bulbar sheath

A

Fascial sheath that envelops eyeball, separating it from orbital fat. Blood vessels and nerves that approach the eyeball pierce through the capsule.

Function: position and support eyeball. Permits the action of EOMs which are attached to the Tenon’s capsule.

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

Fascial sheath is separated from the sclera by ___ space

A

Episcleral

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

Anteriorly, the fascial sheath is attached to…

A

Sclera

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

Posteriorly, the fascial sheath fuses with the…

A

Meninges around optic nerve

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

The modified tenon’s capsule has expansions around…

A

EOMs, medial and lateral check ligaments, and around the ligament of lockwood.

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

What do check ligaments do?

A

Limit the action of the medial and lateral rectus, and prevent retraction of the globe into the orbital cavity during eye movements.

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

Where are the check ligaments attached to?

A

Attached to the lateral wall of the orbital, lacrimal, and zygomatic bones.

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

The suspensory ligament (of lockwood) is formed by…

A

Blending of the fascial sheaths o the inferior rectus and inferior oblique bmuscles with part of Tenon’s capsule.

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

What is the name of the structure from which the superior oblique’s tendon runs between?

A

Trochlea

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

Trochlea is fibrocartilage attached to the ____ of the frontal bone

A

trochlear fossa

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

Inferior oblique arises from the ___ bone (in front of the orbit), and inserts into the ___ side of the globe

A

posterior, inferior, lateral surface of the globe.

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

What is the acronym used to remember EOM innervation?

A

LR6(SO4)3

17
Q

Annulus of Zinn is a…

A

Tendinous ring at the apex of the orbital cavity, where rectus and superior oblique muscles arise from.
Located in front of the superior orbital fissure.

18
Q

Cranial Nerve __ leaves the orbit through Annulus of Zinn. Other CN pass into the orbit through the annulus

A

3

19
Q

What is the agonist?

A

Primary muscle that moves an eye in a given direction

20
Q

What is a Synergist?

A

A muscle in the same eye that moves in the same direction as the agonist

21
Q

What is an anagonist?

A

The muscle in the same eye that moves in the opposite direction of the agonist.

22
Q

What is the listing’s law?

A

Listings’ law states that the eye achieves all 2D orientations starting from one specific “primary” reference orientation, then rotating about an axis that lies within the plane orthogonal to the primary orientation’s gaze direction.

23
Q

What is hering’s law?

A

Equal innervation to muscle of both eyes gazing in a particular direction

24
Q

What is sherrington’s law?

A

When one muscle constricts in the eye, the other antagonist muscle relaxes in the same eye.

25
Q

What is Axes of Fick?

A

A movement around an eye around the theoretical enter of rotation. They rotate about 3 potential axes. Ficks’ axes cross at the centre of rotation.

Horizontal eye movements around z axis
vertical eye movements around x axis
Torsional eye movements around y-axis.

26
Q

What are yoke muscles?

A

Primary muscles in each eye that accomplish a given version (i.e. for a right gaze, the right lateral rectus and left medial rectus). By herring’s law, yoke muscles are given equal and simultaneous innervation.

27
Q

What is the secondary action of SR?

A

Intorsion

28
Q

What is the secondary action of IR?

A

Extorsion

29
Q

What is the secondary action of IO?

A

Elevation

30
Q

What is the secondary action of SO?

A

Depression

31
Q

What is the tertiary action for SR and IR?

A

Adduction

32
Q

What is the tertiary action for IO and SO?

A

Abduction

33
Q

What is strabismus/heterotropia?

A

If one eye is constantly in a different direction than the eye that is fixating

34
Q

What is nystagmus?

A

Involuntary, rapid eye movement (physiological - optic kinetic nystagmus (OKN), vestibuloocular reflex, albinism) or (pathological - drug induced)

272A (13 decks)

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