EOM ANATOMY AND KINEMATICS

Question 1

Corresponds to the equatorial plane of the globe

Answer 1

Listings plane

Question 2

Point where there is zero velocity during any eye movement

Answer 2

Center of rotation

Question 3

The center of rotation is not a fixed point

Answer 3

It is a locus of points

Question 4

The center of rotation is space centroid/ body centrode

Answer 4

Due to the fact that due rotation is accompanies by small translational movement

Question 5

Center of rotation is said to be about 13.5mm from

Answer 5

Corneal apex

Question 6

Rotation of one eye around z axis

Answer 6

Abduction

Question 7

Rotation of one eye one x axis

Answer 7

Elevation & depression

Question 8

Rotation of one eye on y axis

Answer 8

Intorsion and extortion

Question 9

Muscles that originate at the back of the orbit in the common tendinous ring or annulus of zinn

Answer 9

All rectus & superior oblique

Question 10

Thickest of the EOMS

Answer 10

Medial rectus

Question 11

Shortest of the eye muscles

Answer 11

Lateral rectus

Question 12

Longest of the recto muscles

Answer 12

Superior rectus

Question 13

Longest and thinnest of the EOMS

Answer 13

SO

Question 14

Originates from the front of the orbit floor on the nasal side

Answer 14

Inferior oblique

Question 15

Recti muscle attach to the globe ___ mm from the limbus

Answer 15

MR=5
IR=6
LR=7
SR=8

Question 16

Spiral of tillaux

Answer 16

Attachments of recti muscle form a spiral pattern around the limbus

Question 17

Actions of the SR

Answer 17

Elevation
Intortion
Adduction

Question 18

When the SR is looking out temporally

Answer 18

The only action is elevation

Question 19

When SR is looking in (nasally) the only action is

Answer 19

Intortion

Question 20

Actions of IR at primary gaze

Answer 20

Depression
Extortion
Adduction

Question 21

If eye is looking temporally IR purely

Answer 21

Depresses

Question 22

If eye is turned nasally, IR only

Answer 22

Extorts

Question 23

As the eye is adducted, SR and IR produce

Answer 23

More torsion but less vertical movement

Question 24

SR and IR are most effective vertical movers when the eye is

Answer 24

Abducted

Question 25

When the eye is turned in the SO action is

Answer 25

Pure depressor

Question 26

When there eye is turned out, SO’s action is pure

Answer 26

Intortion

Question 27

In primary position SO actions include

Answer 27

Intortion
Depression
Abduction