EOM

Question 1

Origin of ALL Recti muscles”

Answer 1

annulus of zinn

Question 2

Blood supply of Recti muscles:

Answer 2

Muscular Arteries

except LR (partially supplied by Lacrimal Artery)

Question 3

Longest EOM without tendon:

Answer 3

Superior Rectus

Question 4

strongest among the recti muscle:

Answer 4

Medial rectus

Question 5

arises by 2 heads (HAS Upper & lower portion)

Answer 5

LR

Question 6

Insertion of OBLIQUE muscles:

Answer 6

inserted behind the equator of sclera

Question 7

Longest EOM from origin to insertion (With tendon)

Answer 7

Superior Oblique

Question 8

origin of SO:

Answer 8

periosteum of lesser wing of sphenoid above & medial to the optic foramen

(near the annulus of zinn)

Question 9

Shortest EOM:

Answer 9

Inferior oblique

Question 10

origin of Inferior oblique

Answer 10

Orbital plate of maxilla behind the orbital margin

lateral to nasolacrimal groove

FLOOR OF BONY ORBIT

Question 11

muscles that originate from annulus of Zinn:

Answer 11

4 rectus muscle

LPS

SO

Question 12

Insertion of SR:

Answer 12

7.7 mm from LIMBUS

Question 13

Insertion of MR:

Answer 13

5.5 mm from LIMBUS

Question 14

insertion of IR:

Answer 14

6.5 mm from LIMBUS

Question 15

Insertion of LR:

Answer 15

6.9 mm from LIMBUS

Question 16

Insertion of SO:

Answer 16

Bends backward at an angle of 55 degrees passing under SR

Insert to Supero-posterior quadrant of eyeball behind equator

Question 17

Insertion of IO:

Answer 17

passes outward and backward at an angle of 51 degrees to visual axis

lies first between IR & Orbital floor then beneath the LR

to be inserted inferio-posterior of eyeball behind equator

Question 18

short, funnel shaped tendinous ring enclosing the optic foramen and is attached to medial end of SOF:

Answer 18

Annulus of ZINN

or common tendinous ring

Question 19

Structures passing Annulus of Zinn:

Answer 19

CN 2 - optic

CN 3 - oculomotor nerve

CN 5 - nasocilary branch

CN 6 - abducens

Ophthalmic arteries

Question 20

Blood supply of EOM:

Answer 20

Muscular arteries - branch of Ophthalmic artery

Each recuts muscle is suppled by 2 muscular arteries

except LR which is partially supplied by Lacrimal Artery

Question 21

All EOM form the Muscle Cone except:

Answer 21

Inferior oblique

Question 22

apex of muscle cone:

Answer 22

Posterior Orbit

Question 23

base of muscle cone:

Answer 23

Attachment of the muscles around midline of eye

Question 24

MR from insertion to limbus:

Answer 24

5.5 mm

Question 25

LR from insertion to limbus:

Answer 25

6.9 mm

Question 26

IR from insertion to limbus:

Answer 26

6.5 mm

Question 27

SR from insertion to limbus:

Answer 27

7.7 mm

Question 28

SO from insertion to limbus:

Answer 28

7-18 mm

Question 29

IO from insertion to limbus:

Answer 29

5-14 mm

Question 30

measurements of SR:

Answer 30

LENGTH = 41.8 mm TENDON = 5.8 mm WIDTH = 10.6 mm

Question 31

measurements of SO:

Answer 31

LENGTH = 40 mm TENDON = 20 mm WIDTH = 10.8mm

Question 32

Shortest EOM:

Answer 32

Inferior Oblique = 37 mm

Question 33

the only EOMs in which the muscles axis is aligned w/ optical axis of the eye in the primary position

Answer 33

MR and LR

Question 34

Broadest of the EOM:

Answer 34

MEDIAL RECTUS

Question 35

EOM which has NO tendon:

Answer 35

Medial rectus