Eye and Eye Movements

Question 1

What bone is usually involved in a blow out fracture?

Answer 1

Maxillary bone part of the orbital wall (medially/inferiorly)

Question 2

What movements of the pupil happen around the vertical axis, horizontal axis, and AP axis?

Answer 2

Vertical - ABduction/ADduction
Horizontal - Elevation/Depression
AP - Intorsion (medial rotation)/Extorsion (lateral rotation)

Question 3

Where does the levator palpebrae superioris m attach?

Answer 3

Sphenoid bone to upper eyelid

Question 4

What is the action and innervation of levator palpebrae superioris m?

Answer 4

Elevates eyelid and innervated by CN III

Question 5

What muscle/nerve closes eye? What muscle/nerve opens eye?

Answer 5

Closes - orbicularis oculi m (CN VII)

Opens - levator palpebrae superioris m (CN III)

Question 6

What innervates the superior oblique m?

Answer 6

CN IV (Trochlear n)

Question 7

What innervates the lateral rectus m?

Answer 7

CN VI (Abducens n)

Question 8

What muscles are elevators of the eye?

Answer 8

Inferior oblique m and superior rectus m

Question 9

What muscles are depressors of the eye?

Answer 9

Superior oblique m and inferior rectus m

Question 10

What is the tendinous ring?

Answer 10

Tendons of the rectus muscles

Question 11

What nerves go through JUST the superior orbital fissure?

Answer 11

Frontal n, lacrimal n, trochlear n

Question 12

What nerves go through the superior orbital fissure AND the tendinous ring?

Answer 12

Oculomotor n (superior and inferior divisions), nasociliary n, abducent n

Question 13

What does the optic nerve travel through?

Answer 13

The optic canal AND the tendinous ring

Question 14

What do sympathetic nerves that jump on the external carotid plexus do?

Answer 14

Salivary glands (dry/mucous secretions), sweat glands, constrict blood vessels

Question 15

What do sympathetic nerves that jump on the internal carotid plexus do?

Answer 15

Dilate pupil and aid in keeping eyelid open (tarsus m)

Question 16

What nerves make up the nerve of the pterygoid canal? What does this nerve do?

Answer 16

Deep petrosal n (sympathetic n) and greater petrosal n (parasympathetic n). Nerve goes to pterygopalatine ganglion and to blood vessels

Question 17

What is Horner’s syndrome?

Answer 17

Damage to the superior cervical ganglion. Ptosis, anhydrosis, constricted pupil, flushing of skin (dilated blood vessels)

Question 18

What do presynaptic parasympathetic nerves travel with? Where do they synapse?

Answer 18

Oculomotor n, ciliary ganglion

Question 19

What do parasympathetic nerves do?

Answer 19

Constrict the pupil

Question 20

What is trochlear n palsy?

Answer 20

Superior oblique m no longer works, lateral rotators don’t work so head tilts away from affected side. Also usually depresses eye so when looking down, one eye doesn’t move down and one does so you get diplopia

Question 21

What is abducens palsy?

Answer 21

Cannot look laterally/abduct eye

Question 22

What is oculomotor palsy?

Answer 22

Eye is down and out (only muscles left are superior oblique m and lateral rectus m), complete ptosis due to loss of levator palpebrae superioris m, pupil dilation due to loss of parasympathetic innervation to pupil

Question 23

What two components does any reflex have?

Answer 23

A sensory and motor component

Question 24

What is the pupillary light reflex?

Answer 24

A 4-neuron arch. Sensory component - optic n.

Motor component - parasympathetics traveling with CN III

Question 25

What is the corneal reflex?

Answer 25

Sensory component - trigeminal V1 | Motor component - facial n (closes eye with orbicularis oculi m)

Question 26

What are the layers of the eyeball?

Answer 26

Fibrous layer - sclera and cornea Vascular layer - choroid, ciliary body, iris Inner layer - retina

Question 27

What is the optic n surrounded by and what is contained within the nerve?

Answer 27

Dura mater, arachnoid mater, pia mater. | Central retinal v and a

Question 28

What are the two conjunctiiva and where are they?

Answer 28

Palpebral conjunctiva lines innermost part of eyelid | Bulbar conjuncitva lines outermost part of eyeball

Question 29

Where do the two types of conjunctiva come together

Answer 29

Superior conjunctional fornix

Question 30

What is the difference between levator palpebrae superioris m and superior tarsal m?

Answer 30

LPS pulls eyelid up and is innervated by CN III | Superior tarsal m keeps eyelid up and is innervated by sympathetic nervous fibers

Question 31

What is a subconjuncival hemorrhage?

Answer 31

Rupture of blood vessel between sclera and bulbar conjunctiva when abdominal pressure increases

Question 32

What is complete vs partial ptosis?

Answer 32

Complete - LPS or CN III damage | Partial - tarsal m problem

Question 33

What is papilledema?

Answer 33

Bulging optic disc caused by increased intracranial pressure

Question 34

What are the anastamoses around the eye?

Answer 34

Supratrochlear a and angular a Supraorbital a and superficial temporal a Ethmoidal a and sphenopalatine a Lacrimal a and middle meningeal a

Question 35

Which important artery of the eye does not anastomose with anything?

Answer 35

Central retinal a

Question 36

What is the clinical presentation of a central retinal vein occlusion?

Answer 36

Ketchup splotches on retina. Caused by hardening of central retinal a or hemorrhages

Question 37

What is the clinical presentation of a central retinal artery occlusion?

Answer 37

Pale and red spot. Pale due to occluded artery, red spot is macula taht is supplied by the choroid. Can be caused by an embolism

Question 38

What makes up the lacrimal apparatus?

Answer 38

``` Lacrimal gland (makes tears) Lacrimal canaliculi (two small straws that wick tears) Lacrimal sac (collects tears from lacrimal canaliculi) Nasolacrimal duct (drains lacrimal sac) ```

Question 39

What is the pathway the facial nerve takes to get to the lacrimal gland?

Answer 39

Internal auditory meatus to petrous part of temporal bone Through geniculate ganglion without synapsing Exit through hiatus for greater petrosal n Becomes greater petrosal n Meets up w/ deep petrosal n (postsynaptic sympathetic) Goes through pterygoid canal and becomes n of pterygoid canal Synapses at pterygopalatine ganglion Jumps onto zygomatic branch of V2 Jumps onto lacrimal n of V1 via communicating branch

Question 40

Where is the anterior chamber?

Answer 40

Between cornea and iris

Question 41

Where is the posterior chamber?

Answer 41

Between iris and lens/ciliary body

Question 42

Where is the vitreous chamber?

Answer 42

Behind lens

Question 43

What is the ciliary body?

Answer 43

Composed of ciliary m and ciliary processes. Innervated by parasymp of oculomotor n.

Question 44

What are ciliary processes?

Answer 44

Secrete aqueous humor that fills anterior and posterior chambers

Question 45

How does the aqueous humor flow?

Answer 45

From posterior chamber to pupil and around iris to anterior chamber, drains through Schlemm's canal

Question 46

What happens if Schlemm's canal is blocked?

Answer 46

Increased intra-ocular pressure due to continued secretion of aqueous humor = glaucoma, can compress optic n

Question 47

What is a hyphema?

Answer 47

Rupture of vessel in anterior chamber

Question 48

What does the ciliary body do to the lens when it contracts?

Answer 48

Relaxes suspensory ligaments (zonular fibers) which allows lens to get rounder instead of flat (to see closer)

Question 49

What makes up accommodation?

Answer 49

Convergence of eyes, pupil constriction, rounding of lens