Orbit II

Question 1

Name the 4 rectus muscles of the eye

Answer 1

• superior rectus
• inferior rectus
• lateral rectus
• medial rectus

Question 2

Name the 2 oblique muscles of the eye

Answer 2

• Superior oblique
• Inferior oblique

Question 3

What makes up the common tendinous ring

Answer 3

Point of origin of 4 of the the muscles of the orbit

• superior rectus
• Inferior rectus
• Lateral rectus
• Medial rectus

encloses optic canal and superior orbital fissure

Question 4

What is the insertion and action of the levator palpebrae superioris muscle?

Answer 4

• Insertion: superior tarsal plate
• action: elevate upper eyelid

Question 5

What is the innervation of the Levator Palpebrae superioris m. and Superior rectus m.

Answer 5

Superior division of oculomotor (CN III)

Question 6

What nerve innervates lateral rectus m.

Answer 6

abducent (CN VI)

Question 7

What nerve innervates inferior rectus m. and medial rectus m.

Answer 7

inferior division of oculomotor (CN III)

Question 8

What nerve innervates the superior oblique m.

Answer 8

Trochlear (CN IV)

Question 9

What nerve innervates the inferior oblique m.

Answer 9

inferior division of oculomotor CN III

Question 10

What is the action of the medial rectus m.

Answer 10

STRONG adduction

Question 11

Action of lateral rectus

Answer 11

STRONG ABduction

Question 12

What is the action of the superior rectus m.

Answer 12

Strong elevation

Slight adduction

Intorsion

• muscle lies at a angle from the medial wall of the orbit

Question 13

What is the action on inferior rectus m.

Answer 13

• strong depression
• slight adduction
• extorsion

Question 14

What is the action of the superior oblique

Answer 14

• strong depression
• slight abduction
• intorsion

Question 15

What is the action of the inferior oblique m.

Answer 15

• strong elevation
• slight abduction
• extorsion

Question 16

intorsion vs extorsion

Answer 16

Rotation of upper cornea toward (intorsion) or away (Extorsion) from midline

Question 17

How can you test if a patient’s superior oblique m. is not functioning?

Answer 17

Have him/her adduct the eye (via medial rectus) and now superior oblique is a pure depressor

* inferior rectus cannot depress in this state; it now produces pure extorsion

Question 18

How can you check to see if superior rectus m. is functioning?

Answer 18

Have patient Abduct his/her eye (via lateral rectus); superior rectus is now a pure elevator

• inferior oblique cannot elevate; it ow produces pure extorsion

Question 19

Name the two divisions of the oculomotor nerve (CN III).

Answer 19

• Superior and Inferior division

Question 20

The superior division of oculomotor n (CN III) gives motor innervation to what 2 muscles?

Answer 20

• superior rectus
• Levator palpebrae superioris

Question 21

The inferior division supplies what (3 muscles) and has what type of innervation

Answer 21

• medial rectus
• inferior rectus
• inferior oblique
• motor; preganglionic parasympathetics

Question 22

How can you distinguish the trochlear nerve after it exits the superior orbital fissure

Answer 22

passes along the superior surface of the superior oblique muscle

Question 23

How can you distinguish the abducent nerve (CN VI) after it exits the superior orbital fissure

Answer 23

passes along the medial side of the lateral rectus muscle

Question 24

any nerve passing through the superior orbital fissure passes through what sinus

Answer 24

cavernous sinus

Question 25

Identify purple arrow

Answer 25

cavernous sinus

Question 26

identify blue

Answer 26

oculomotor (III)

Question 27

orange

Answer 27

Trochlear n ( CN IV)

Question 28

black

Answer 28

ophthalmic n. of trigeminal (CN V1)

Question 29

green

Answer 29

maxillary nerve of trigeminal (CN V2)

Question 30

identify

Answer 30

abducent nerve