Muscles of the Eye

Question 1

How many muscles control the movements of the eyeball?

Answer 1

6

Question 2

What are the categories of muscle controlling the eye?

Answer 2

• Recti (4)
• Oblique (2)

Question 3

What do all the recti muscles of the eye arise from?

Answer 3

Common tendinous ring

Question 4

What is the common tendinous ring?

Answer 4

A fibrous cuff that surrounds the optic canal

Question 5

Draw a diagram illustrating the action of muscles on the eyeball

Answer 5

Question 6

What is the origin of the superior rectus?

Answer 6

Superior part of the common tendionous ring

Question 7

What is the insertion of the superior rectus?

Answer 7

Superior and anterior aspect of sclera

Question 8

What is the innervation of the superior rectus?

Answer 8

Oculomotor nerve

Question 9

What is the action of the superior rectus?

Answer 9

• Elevation
• Contributes to adduction and medial rotation

Question 10

What is the origin of the inferior rectus?

Answer 10

Inferior part of common tendinous ring

Question 11

What is the insertion of the inferior rectus?

Answer 11

Inferior and anterior aspect of the sclera

Question 12

What is the innervation of the inferior rectus?

Answer 12

Oculomotor nerve

Question 13

What is the action of the inferior rectus?

Answer 13

• Depression
• Contributes to the adduction and lateral rotation of the eyeball

Question 14

What is the origin of the medial rectus?

Answer 14

Medial part of common tendinous ring

Question 15

What is the insertion of the medial rectus?

Answer 15

Antero-medial aspect of sclera

Question 16

What is the innervation of the medial rectus?

Answer 16

Oculomotor nerve

Question 17

What is the action of the medial rectus?

Answer 17

Adducts

Question 18

What is the origin of the lateral rectus?

Answer 18

Lateral part of the common tendinous ring

Question 19

What is the insertion of the lateral rectus?

Answer 19

Antero-lateral aspect of sclera

Question 20

What is the innervation of the lateral rectus?

Answer 20

Abducens nerve

Question 21

What is the action of the lateral rectus?

Answer 21

Abducts

Question 22

What is the origin of the superior oblique?

Answer 22

Body of sphenoid bone

Question 23

What is the insertion of the superior oblique?

Answer 23

Sclera of eye, posterior to superior rectus

Question 24

What is the innervation of the superior oblique?

Answer 24

Trochlear nerve

Question 25

What is the action of the superior oblique?

Answer 25

Depresses, abducts, and medially rotates

Question 26

What is the origin of the inferior oblique?

Answer 26

Anterior aspect of the orbital floor

Question 27

What is the insertion of the inferior oblique?

Answer 27

Sclera of eye, posterior to lateral rectus

Question 28

What is the innervation of the inferior oblique?

Answer 28

Oculomotor nerve

Question 29

What is the action of the inferior oblique?

Answer 29

Elevates, abducts, and laterally rotates the eyeball

Question 30

What does movement of the eyelids occur via the action of?

Answer 30

* Orbicularis oculi muscle * Levator palpebrae superioris muscle

Question 31

What does the orbicularis oculi muscle do?

Answer 31

Closes the eyelid

Question 32

What is the orbicularis oculi muscle innervated by?

Answer 32

The facial nerve

Question 33

What does the levator palpebrae superioris muscle do?

Answer 33

Opens the eyelid

Question 34

What is the leavtor palpebrae superioris muscle innervated by?

Answer 34

The oculomotor nerve

Question 35

What is complete ptosis caused by?

Answer 35

A CN III lesion

Question 36

What is partial ptosis caused by?

Answer 36

A sympathetic lesion