Orbit

Question 1

Action of lateral rectus

Answer 1

Abducts eye

Question 2

Action of medial rectus

Answer 2

Adducts eye

Question 3

Action of inferior oblique

Answer 3

Directs eye up and out

Question 4

Action of superior oblique

Answer 4

Directs eye down and out

Question 5

Action of superior rectus

Answer 5

Directs the eye up and in

Question 6

Action of inferior rectus

Answer 6

Directs eye down and in

Question 7

Action of superior rectus + superior oblique

Answer 7

Intorts eye

Question 8

Action of inferior rectus and inferior oblique

Answer 8

Extorts eye

Question 9

Action of inferior oblique and superior rectus

Answer 9

Elevates eye

Question 10

Action of superior oblique and inferior rectus

Answer 10

Depresses the eye

Question 11

Action of lateral rectus, inferior and superior oblique

Answer 11

Abducts eye

Question 12

Action of medial rectus, inferior and superior rectus

Answer 12

Adducts eye

Question 13

H-test. Patient directs the eye medially, what muscles are being held in place?

Answer 13

Superior and inferior rectus

Question 14

H-test: patient directs the eye medially, the patient looks up. What muscle is being tested?

Answer 14

Inferior oblique

Question 15

H-test: patient directs the eye medially, the patient looks down. What muscle is being tested?

Answer 15

Superior oblique muscle

Question 16

H-test: patient directs the eye laterally, what muscles are being held in place?

Answer 16

Superior and inferior oblique

Question 17

H-test: patient directs the eye laterally, the patient looks up. What muscle is being tested?

Answer 17

Superior rectus

Question 18

H-test: patient directs the eye laterally, the patient looks down. What muscle is being tested?

Answer 18

Inferior rectus

Question 19

What nerve innervates superior oblique?

Answer 19

Trochlear nreve

Question 20

What nerve innervates lateral rectus?

Answer 20

Abducent

Question 21

What nerve innervates superior and inferior rectus, inferior oblique, and medial rectus?

Answer 21

Oculomotor

Question 22

If problems arise in the cavernous sinus, which structures may be compromised?

Answer 22

CN (Occulomotor, Trochlear, Opthalmic, Maxillary) which all travel in the wall of the cavernous sinus

CN (abducent) and internal carotid

Optic nerve

Pituitary gland

Question 23

What are the structures of the orbit from superior to inferior that enter the orbit above the common tendinous ring

Answer 23

Frontal nerve

Lacrimal nerve

Trochlear nerve

Superior opthalmic vein

Question 24

What structures cross over the top of the optic nerve?

Answer 24

Opthalmic artery and the nasociliary nerve

Question 25

What artery pierces the optic nerve?

Answer 25

Central retinal

Question 26

What is the consequence of an abducent nerve lesion?

Answer 26

Loss of lateral rectus muscle

Eye is turned medially

Question 27

What is the consequence of a trochlear nerve lesion?

Answer 27

Loss of superior oblique muscle

Eye is turned down and out

Affected eye is higher and deviated medially

Head tilt

Question 28

What is the consequence of a oculomotor nerve lesion

Answer 28

Oculomotor palsy

Loss of all but lateral rectus and supeior oblique muscle

Eye is directed downward and laterally

Question 29

Carotid-cavernous sinus fistula is caused by

Answer 29

Rupture of internal carotid artery or its smaller dural branches in the cavernous sinus