Extra- Ocular muscles of orbit

Question 1

Origin: Levator palpebrae superioris

Answer 1

Lesser wing of sphenoid bone, superior and anterior to optic canal

Question 2

Insertion: Levator palpebrae superioris

Answer 2

Superior tarsus and skin of superior eyelid

Question 3

N. Innervation: levator palpebrae superioris

Answer 3

• Oculomotor nerve (CNIII)

- Deep layer is suppled by sympathetic fibers

Question 4

Action: levator palpebrae superioris

Answer 4

Elevates superior eyelid

Question 5

Origin: Superior oblique

Answer 5

Body of sphenoid bone

Question 6

Insertion: superior oblique

Answer 6

It’s tendon passes through a fibrous ring (trochlea), changes its direction, and inserts into sclera deep to superior rectus muscle

Question 7

N. Innervation: superior oblique

Answer 7

Trochelar nerve (CN IV)

Question 8

Action: superior oblique

Answer 8

Abducts, depresses, and medially rotates eyeball

Question 9

Origin: Inferior oblique

Answer 9

Common tendinous ring

Question 10

Insertion: inferior oblique

Answer 10

Sclera deep to lateral rectus muscle

Question 11

Action: inferior oblique

Answer 11

Elevates, adducts, and medially rotates eyebal

Question 12

Origin: inferior rectus

Answer 12

Common tendinous ring

Question 13

Insertion: inferior rectus

Answer 13

sclera just posterior to corner-scleral junction

Question 14

N. Innervation: inferior rectus

Answer 14

Oculomotor (CN III)

Question 15

Action: inferior rectus

Answer 15

adducts eyeball

Question 16

Origin: lateral rectus

Answer 16

common tendinous ring

Question 17

Insertion: lateral rectus

Answer 17

sclera just posterior to corner-scleral junction

Question 18

N. Innervation: lateral rectus

Answer 18

Abducent nerve (CN VI)

Question 19

Action: lateral rectus

Answer 19

Abducts eyeball

Question 20

N. innervation: inferior oblique

Answer 20

Oculomotor nerve (CN III)