Anatomy of The Eye & Orbit

Question 1

The Optic canal is the opening for the… (2 structures)

Answer 1

Optic nerve

Ophthalmic artery

Question 2

The Superior Orbital Fissure is the opening for…( 5 structures) (hint they come from the cavernous sinus)

Answer 2

CN III
CN IV
CN V1
CN VI
Superior Ophthalmic veins

Question 3

The Infraorbital nerve (V2) comes out of the skull through the…

Answer 3

Infraorbital foramen (orange)

Question 4

Foramina in the orbit for ethmoidal nerves and vessels

Answer 4

Ethmoidal foramina

Question 5

Transparent, anterior part of the Sclera; largely avascular but has highest density of pain receptors in body; provides structural support to eye

Answer 5

Cornea

Question 6

The Cornea is mostly (vascular/avascular)

Answer 6

Avascular

Question 7

Middle, vascular layer that provides oxygen and nutrients to the retina; continue anteriorly as the Ciliary Body/Muscle

Answer 7

Choroid

Question 8

Short, tendon-like fibers from the choroid that attach to the lens and control its shape and thickness

Answer 8

Zonular fibers

Question 9

The Pupillary (Sphincter/Dilator) muscle is a SMOOTH muscle that constricts the pupil under parasympathetic control

Answer 9

Sphincter

Question 10

The Pupillary (Sphincter/Dilator) muscle is a SMOOTH muscle that dilates the pupil under sympathetic control

Answer 10

Dilator

Question 11

The Pupillary Sphincer and Dilator muscles are _____________ muscle

Answer 11

Smooth (thus under autonomic control)

Question 12

_______ is an area of intense visual acuity located just lateral to the optic disc, and _________ is the area of highest visual acuity within it.

Answer 12

Macula; fovea centralis

Question 13

Part of the eyelid; bands of dense CT that provide structure and support the eyelid

Answer 13

Tarsal plates

Question 14

Glands that provide lubrication for the eyelids

Answer 14

Tarsal glands

Question 15

Inside part of the eyelid; is in direct contact with the eye

Answer 15

Palperbral Conjunctiva

Question 16

A sphincter muscle that closes the eyelids; innervated by the Facial nerve (CN VII);

Answer 16

Orbicularis Oculi

Question 17

Muscle of the eye that opens the eye by lifting the upper eyelid; innervated by Oculomotor nerve (CN III)

Answer 17

Levator Palpebrae Superioris

Question 18

A small smooth muscle under levator palpaebrae superioris that helps lift/open upper lid; innervated by sympathetic nerves

Answer 18

Superior Tarsal

Question 19

Structure that helps limit the spread of infection to and from the orbit

Answer 19

Orbital Septum

Question 20

Glands that produce and secrete tears; parasympathetic innervation from a branch of the facial nerve (CN 7)

Answer 20

Lacrimal Gland

Question 21

Dilated superior portion of the Nasolacrimal duct that receives tears from the eye

Answer 21

Lacrimal sac

Question 22

Membranous structure that drains tears into the Inferior Meatus within the nasal cavity

Answer 22

Nasolacrimal duct

Question 23

The Nasolacrimal duct drains into which Meatus

Answer 23

Inferior Meatus

Question 24

What are the 4 rectus muscles of the eye

Answer 24

Superior rectus
Inferior rectus
Medial rectus
Lateral rectus

Question 25

What are the 2 oblique muscles of the eye

Answer 25

Superior oblique | Inferior oblique

Question 26

Which eye muscle is the ONLY one innervated by Cranial nerve #6 (Abducens)

Answer 26

Lateral rectus

Question 27

Which eye muscle is the ONLY one innervated by Cranial nerve #4 (Trochlear)

Answer 27

Superior Oblique

Question 28

Most eye muscles (4/6) are innervated by what cranial nerve

Answer 28

Oculomotor (CN III) (red)

Question 29

Most eye muscles arise from a ____________ at the back of the orbit EXCEPT _________

Answer 29

Common Tendinous Ring; inferior oblique

Question 30

The Medial Rectus eye muscle moves the eye in what direction?

Answer 30

Adducts (toward nose)

Question 31

The Lateral Rectus eye muscle moves the eye in what direction?

Answer 31

Abducts (away from nose)

Question 32

The Superior Rectus eye muscle moves the eye in what direction?

Answer 32

Up and In

Question 33

The Inferior Rectus eye muscle moves the eye in what direction?

Answer 33

Down and In

Question 34

The Superior Oblique eye muscle moves the eye in what direction?

Answer 34

Down and out

Question 35

The Inferior Oblique eye muscle moves the eye in what direction?

Answer 35

Up and Out

Question 36

If you want to isolate and test the Superior Rectus eye muscle, what do you tell the patient to do

Answer 36

Look laterally, then UP

Question 37

If you want to isolate and test the Inferior Rectus eye muscle, what do you tell the patient to do

Answer 37

Look laterally, the DOWN

Question 38

If you want to isolate and test the Superior Oblique eye muscle, what do you tell the patient to do

Answer 38

Look medially, then DOWN

Question 39

If you want to isolate and test the Inferior Oblique eye muscle, what do you tell the patient to do

Answer 39

Look medially, then UP

Question 40

The eye receives much of its blood supply from what artery

Answer 40

Internal Carotid artery

Question 41

Branch of the Internal Carotid artery that passes through the Optic Canal to alongside the Optic nerve

Answer 41

Ophthalmic artery

Question 42

Branch of the Ophthalmic artery that is the SOLE arterial supply for the retina

Answer 42

Central Retinal artery

Question 43

Veins around the eye that drain into cavernous sinus

Answer 43

Superior/Inferior Ophthalmic veins

Question 44

Since the Superior and Inferior Ophthalmic veins are valveless, they can drain into both the Cavernous Sinus and the _________ vein as well

Answer 44

Facial

Question 45

Branch of the Ophthalmic nerve (V1); conveys sensory information from the eyeball/cornea

Answer 45

Nasociliary nerve * Corneal reflex

Question 46

The Oculomotor nerve, besides just innervating eye muscles, also conveys parasympathetic innervation to what structures internal eye structures

Answer 46

Pupil constriction (Pupillary Sphincter muscle)

Question 47

What 4 media does light have to pass through before focusing on the retina?

Answer 47

Cornea (primary refractive media) Aqueous humor (anterior and posterior chambers) Lens Vitreous

Question 48

What parasympathetic branch nerve of CN 7 hitchhike and join the lacrimal nerve (a branch of CN V1) to innervate lacrimal gland? Damage to this nerve can cause unilateral dry eye!

Answer 48

Greater petrosal nerve * a branch of facial nerve