Eye and Orbital Anatomy

Question 1

What muscle moves the scalp and raises eyebrows?

Answer 1

frontalis

Question 2

What muscle pulls medial eyebrow inferior?

Answer 2

corrugator

Question 3

What muscle pulls forehead and eyebrow inferior?

Answer 3

procerus

Question 4

What nerve opens the eye?

Answer 4

CN3

Question 5

What nerve closes the eye?

Answer 5

CN7

Question 6

What fuses with the septum at arcus marginalus in the anterior and dura of optic nerve in the posterior and is attached firmly at orbital rim and suture lines?

Answer 6

periosteum

Question 7

What muscle move the eye from side to side and what innervates it?

Answer 7

superior oblique muscle
CN IV
inferior oblique muscle
CN III

Question 8

What muscle elevates the eye and what innervates it?

Answer 8

superior rectus muscle

CN III

Question 9

What muscle depresses the eye and what innervates it?

Answer 9

inferior rectus muscle

CN III

Question 10

What muscle adducts the eye and what innervates it?

Answer 10

medial rectus muscle

CN III

Question 11

What muscle abducts the eye lateral and what innervates it?

Answer 11

lateral rectus muscle

CN VI

Question 12

What is it called when the eye turns in?

Answer 12

esotropia

Question 13

What is it called when the eye turns out?

Answer 13

exotropia

Question 14

What is it called when the eye turns down?

Answer 14

hypotropia

Question 15

What is it called when the eye turns up?

Answer 15

hypertropia

Question 16

What muscles do CN III innervate?

Answer 16

• medial rectus
• superior rectus
• inferior rectus
• inferior oblique
• levator palpebrae
• pupillary light reflect

Question 17

What muscles does CN IV innervate?

Answer 17

• superior oblique

Question 18

What is the easiest cranial nerve to damage in head trauma?

Answer 18

CN IV (Trochlear)

Question 19

What are the three branches of V1?

Answer 19

• lacrimal
• frontal
• nasociliary

Question 20

What provides sensation to the cornea and can be affected in Zoster infx?

Answer 20

CN V1

Question 21

What nerve innervates the lateral rectus?

Answer 21

CN VI

Question 22

What nerve palsy is common in small strokes?

Answer 22

CN VI

Question 23

What nerve is easily affected in increased intracranial pressure and is a common cause of double vision?

Answer 23

CN VI

Question 24

What nerve innervates the muscles of facial expression?

Answer 24

CN VII

Question 25

What nerve stimulates tear production and is involved in Bell’s palsy?

Answer 25

CN VII

Question 26

The nerves and muscles of the eye come together in the ______.

Answer 26

Annulus of Zinn

Question 27

What nerve is responsible for accomodation (pupil constriction)?

Answer 27

parasympathetic nerve

Question 28

What nerve is responsible for pupil dilation, vasoconstriction, hidrosis and is implicated in Horner’s syndrome?

Answer 28

sympathetic nerve

Question 29

What are the 7 bones of the orbit?

Answer 29

Roof
- frontal
- lesser wing of the sphenoid
Lateral Wall
- zygomatic bone
- greater wing of the sphenoid
Medial Wall
- sphenoid
- maxillary 
- ethmoid
Floor
- lacarimal
- zygomatic 
- palatine
- maxillary

Question 30

What is the thickest and strongest wall of the orbit?

Answer 30

lateral wall

Question 31

What wall is often removed in orbital surgery to improve exposure?

Answer 31

lateral wall

Question 32

What is the thinnest wall of the orbit?

Answer 32

medial wall

Question 33

What is the thinnest bone in the thinnest wall of the orbit (is commonly fractured)?

Answer 33

lamina papyracea

Question 34

What is the common site of cellulitis extension?

Answer 34

lamina papyracea

Question 35

What part of the orbit is often fractured in blunt force trauma?

Answer 35

the floor

Question 36

What are the nerves of the orbit in order?

Answer 36

lacrimal nerve (V1)
frontal Nerve (V1)
trochlear nerve (CN IV)
superior divison of CN III
nasociliary nerve (V1)
abducens nerve (CN VI)
Inferior division of CN III