Anatomy: The Extraocular Muscles

Question 1

Name the muscle shown in blue

Answer 1

Inferior rectus

Question 2

Name the origin of the recti muscles

Answer 2

All originate from common tendinous ring

Question 3

Name the muscles which synergistically depress eyes by working antagonistically as adductors/abductors

Answer 3

Superior oblique and inferior rectus

Question 4

Name the cranial nerve which supplies all of the extra-ocular muscles with the exception of the lateral rectus and the superior oblique?

Answer 4

CN III (oculomotor nerve)

Question 5

The medial rectus can only _____ the eyeball

Answer 5

Adduct

Question 6

When in adduction, the superior oblique can only ______

Answer 6

Depress

Question 7

What is indicated by the arrow?

Answer 7

Superior tarsus muscle

Question 8

Which nerve supplies the levator palpebrae superioris?

Answer 8

CN III

Question 9

The lateral rectus can only _____ the eyeball

Answer 9

Abduct

Question 10

What is indicated by the arrow?

Answer 10

Orbicularis oculi

Question 11

How would you test the function of the superior rectus muscle?

Answer 11

Ask patient to look laterally and upward

Question 12

Name the muscles which synergistically elevate the eyes by working antagonistically as rotators

Answer 12

Superior rectus and inferior oblique

Question 13

Name the origin of levator palpebrae superioris

Answer 13

Lesser wing of sphenoid

Question 14

How would you test the function of the inferior rectus muscle?

Answer 14

Ask patient to look laterally and downward

Question 15

How would you test the function of the lateral rectus muscle?

Answer 15

Ask patient to look laterally

Question 16

Describe the innervation of the superior tarsal muscle (Mueller’s muscle)

Answer 16

Sympathetic fibres from the superior cervical ganglion

Question 17

When in abduction, the superior rectus can only ______

Answer 17

Elevate

Question 18

The tendon of the _______ oblique passes through a trochlea (loop of connective tissue) before inserting onto the eyeball

Answer 18

Superior

Question 19

Which cranial nerve supplies the superior oblique?

Answer 19

CN IV (trochlear nerve)

Question 20

Name the only muscle involved in raising the superior eyelid

Answer 20

Levator palpebrae superioris

Question 21

Name the insertion of the oblique muscles

Answer 21

Both insert onto sclera

Question 22

When in adduction, the inferior oblique can only ______

Answer 22

Elevate

Question 23

Name the insertion of the recti muscles

Answer 23

All insert onto sclera

Question 24

Name the muscle shown in purple

Answer 24

Superior rectus

Question 25

Name the insertion of levator palpebrae superioris

Answer 25

Skin and tarsus of superior eyelid

Question 26

Describe the clinical anatomy of Mueller's muscle relevant to Horner's syndrome

Answer 26

The Mueller's muscle assists the levator in elevating the top eyelid It receives sympathetic innervation which may be compromised in Horner's syndrome causing ptosis

Question 27

Name the origin of the superior oblique

Answer 27

Originates from sphenoid bone

Question 28

Name the muscle shown in orange

Answer 28

Inferior oblique

Question 29

When in abduction, the inferior rectus can only \_\_\_\_\_\_

Answer 29

Depress

Question 30

How would you test the function of the inferior oblique muscle?

Answer 30

Ask patient to look medially and upward

Question 31

Name the muscle shown in red

Answer 31

Levator palpebrae superioris

Question 32

How would you test the function of the medial rectus muscle?

Answer 32

Ask patient to look medially

Question 33

Name the muscle shown in pink

Answer 33

Medial rectus

Question 34

What is indicated by the arrow?

Answer 34

Tendon of levator palpebrae superioris (LPS) muscle

Question 35

Which cranial nerve supplies the lateral rectus?

Answer 35

CN VI (abducent nerve)

Question 36

Name the muscle shown in green

Answer 36

Lateral rectus

Question 37

Name the muscle shown in yellow

Answer 37

Superior oblique

Question 38

How would you test the function of the superior oblique muscle?

Answer 38

Ask patient to look medially and downward

Question 39

Name the action of the superior tarsal muscle (Mueller's muscle)

Answer 39

Assists the levator palpebrae superioris in opening the eyelid

Question 40

What is indicated by the arrow?

Answer 40

Tarsal gland

Question 41

Name the origin of the inferior oblique

Answer 41

Orbital plate of maxilla