GA: Eye + Eye Movements

Question 1

Look at the bones that make up the orbit

Answer 1

Question 2

Where is there most likely to be breakage in an orbital blowout fracture?

Answer 2

Usually medially and inferiorly w/ the maxillary bone.

Orbital contents can prolapse and end up in the maxillary sinus

Question 3

How are the eyeballs positioned within the skull?

Answer 3

medial walls of orbit = parallel

lateral walls = right angle to eachother

axes of gaze = parallel but axes of orbit diverage @ 45 degrees

Question 4

What are the movements of the pupil?

Answer 4

normal primary postion = looking straight forward

Question 5

What does the levator palpebrae superioris m. do + innervation?

Answer 5

Elevates superior eyelid (opens eye)

CN 3

Question 6

What is the function + innervation of superior oblique M.?

Answer 6

ABducts + depresses + medially rotates

CN 4

Question 7

What does inferior oblique M. do + innervation?

Answer 7

ABducts + elevates + laterally rotates eyeball

CN 3

Question 8

Function + Innervation of Superior rectus M.

Answer 8

Elevates + ADduct + rotate medially

CN 3

Question 9

Function + Innervation of Inferior rectus M.

Answer 9

Depresses + ADducts + rotates eyeball laterally

Question 10

Function + Innervation of Medial Rectus

Answer 10

ADducts

CN 3

Question 11

Function + Innervation of Lateral Rectus

Answer 11

ABducts

CN 6

Question 12

Extraocular M.’s

Answer 12

Question 13

What is the prime muscle mover for each of these directions?

Answer 13

Question 14

What is the innervation of the orbit (sensory)?

Answer 14

V1 Opthalamic N. gives off 3 branches:

1) Frontal N. –> Supratrochlear + supraorbital N.’s
2) Lacrimal N.
3) Nasociliary N. –> Posterior ethmoidal N. + Anterior Ethmoidal N. + Infratrochlear N. + Long ciliary N. + Short ciliary N.

Question 15

What is the innervation of the extraocular M.’s?

Answer 15

Oculomotor N. (IO, SR, IR, + LPS to open eye)

Trochlear N. (SO)

Abducent N. (LR)

Question 16

How do the sympathetics infiltrate the eye and what do they make it do?

Answer 16

Sup. Cervical Ganglion –> Internal Carotid Plexus hitch

nasociliary = dilates eye

&

long ciliary = keeps eye open

Question 17

A lesion of CN ____ causes trochlear palsy.

Answer 17

4 = SO

Heaad tilts away from affected side

Question 18

A lesion of CN ____ causes abducens palsy.

Answer 18

6 = lateral rectus

Cannot look laterally w/ affected eye

Question 19

What are the symptoms of oculomotor palsy?

Answer 19

Down + out eye

Complete ptosis

Pupil Dilation (loss of parasympathetics)

Question 20

What should happen in the pupillary light reflex?

Answer 20

Both eyes should constrict

Light synapses in 4 nuclei:

1. Pretectal
2. Edinger-Westphal preganglionic nucleus
3. Ciliary M.
4. Constrictor pupillae M.

Question 21

What should happen in the corneal reflex?

Answer 21

If the cornea detects touch or irritation is should close

CN V –> trigeminal nucleus, facial nucleus, facial N.

Question 22

What are the layers of the eyeball:

1. Fibrous
2. Vascular
3. Inner

Answer 22

Fibrous = sclera + cornea

Vascular = Choroid, Ciliary body, Iris

Inner = Retina

*optic nerve covered w/ all 3 layers of meninges*

Question 23

What lines the innermost part of the eyelids?

Answer 23

Palpebral Conjunctiva

Question 24

What lines the outermost part of the eyeball?

Answer 24

Bulbar (ocular) conjunctiva

Question 25

What muscle is innervated by sympathetics and keeps the eyelid up?

Answer 25

Superior tarsal M.

Question 26

What muscle helps open the eyelid and is inervated by CN 3?

Answer 26

Orbicularis oculi M.

Question 27

What is this?

Answer 27

Subconjunctival hematoma

Question 28

What is another word for pink eye?

Answer 28

Conjunctivitis

Question 29

What muscle is affected in **complete** ptosis?

Answer 29

Levator Palpebrae Superioris \*Also can result from full destruction of CN 3 which opens the eye\*

Question 30

What muscle is affected in **partial** ptosis?

Answer 30

Tarsal muscle which is innervated by **postganglionic sympathetic fibers** seen in horners syndrome

Question 31

What causes papiledema?

Answer 31

Increased intracranial pressure URGENT

Question 32

Label these:

Answer 32

Question 33

What happens if the central retinal artery is occuled?

Answer 33

You will end up blind. This is the only artery supplying the retina.

Question 34

Answer 34

Anastomoses help w/ slow occlusions

Question 35

Where does venous supply of the face drain?

Answer 35

1) Cavernous sinus 2) Pterygoid Venous plexus

Question 36

What is occluded causing this appearence of "ketchup"?

Answer 36

Central Retinal Vein

Question 37

What is occluded causing this "cherry red spot"?

Answer 37

Central Retinal Artery

Question 38

What does the lacrimal appartus function in and what nerve innervates it?

Answer 38

Tear production CN 7 via greater protrusal

Question 39

How does tear production work?

Answer 39

1. Greater petrosal N. + Deep Pretrosal form pterygoid canal 2. Parasym. fibers synapse in pterygopalatine ganglion and travel w/ V2, then sygomatic branch, then lacrimal N. of V1

Question 40

What are the 4 chambers of the eye?

Answer 40

1. Ciliary body 2. Ciliary Processes 3. Anterior Chamber 4. Posterior Chamber

Question 41

How does the aqueous humor flow?

Answer 41

1. Ciliary processes secrete aqueous humor into posterior chamber 2. Flows through pupil to anterior chamber 3. Drains into sclera venous sinus 4. Humor is removed via limbial plexus

Question 42

If you have a blockage of Schlemm's canal (scleral venous sinus) what can happen?

Answer 42

Increased pressure and **glaucoma**

Question 43

What is this?

Answer 43

Hyphema: rupture w/in the anterior chamber of the eye

Question 44

When we need to use near vision like for reading what happens to our eye?

Answer 44

The ciliary muscles contract and this reduces the tension on the suspensory ligament, allowing the lens to become more **rounded**.