12. Eye and Eye Movements

Question 1

bones of the orbit

Answer 1

• frontal
• ethmoid
• sphenoid
• zygomatic
• lacrimal
• maxillary

Question 2

sinus relationships of the eye

Answer 2

• frontal
• ethmoid
• maxillary

Question 3

in what direction does an orbital wall blow-out fracture typically occur

Answer 3

medially and inferiorly (involving maxillary bone)

Question 4

• caused by indirect trauma
• orbital contents may prolape and become entrapped in maxillary sinus
  
  • diplopia, globe ptosis, exophthalmous

Answer 4

orbital blowout fx

Question 5

axes of the orbit diverge at a ___ degree angle

Answer 5

45

Question 6

on what axis does abduction/adduction occur?

Answer 6

vertical axis

Question 7

on what axis does elevation or depression occur?

Answer 7

horizontal axis

Question 8

on what axis does medial rotation/lateral rotation occur?

Answer 8

AP axis

Question 9

elevates the superior eyelid

Answer 9

levator palpebrae superioris m.

Question 10

abducts, depresses, medially rotates eyeball

Answer 10

superior oblique m.

Question 11

abducts, elevates, and laterally rotates eyeball

Answer 11

inferior oblique m.

Question 12

elevates, adducts, and rotates eyeball medially

Answer 12

superior rectus m.

Question 13

depresses, adducts, and rotates eyeball laterally

Answer 13

inferior rectus m.

Question 14

adducts eyeball

Answer 14

medial rectus m.

Question 15

abducts eyeball

Answer 15

lateral rectus m.

Question 16

When the eye is abducted by the lateral rectus, what muscles produce elevation and depression?

Answer 16

superior and inferior rectus, respectively

Question 17

When the eye is adducted by the medial rectus, only what muscles can produce elevation and depression?

Answer 17

oblique muscles

Question 18

main arterial supply of eye and its origin

Answer 18

ophthalmic a. comes from ICA

Question 19

Where do the superior and inferior ophthalmic veins drain into?

Answer 19

cavernous sinus

Question 20

vascular structure encircling anterior chamber of eyeball through which aqueous humor is returned to the blood circulation

Answer 20

scleral venous sinus

Question 21

• head tilts away from affected side
• diplopia worse on downward gaze

Answer 21

trochlear palsy

Question 22

cannot look laterally w/ affected eye

Answer 22

abducens palsy

Question 23

“down and out eye”

Answer 23

loss of ocular innervation

SO and LR intact

*type of oculomotor palsy*

Question 24

loss of innervation to levator palpebrae superioris m.

Answer 24

complete ptosis

*type of oculomotor palsy*

Question 25

loss of parasympatheitc innervation to pupil causes \_\_\_

Answer 25

pupil dilation \*type of oculomotor palsy\*

Question 26

Horner syndome

Answer 26

interrupted sympathetic nerve supply characteristics: * **miosis**: constricted pupil * **ptosis**: drooping superior eyelid * **anhydrosis**: absence of sweating * **vasodilation**: increased temp of skin + redness

Question 27

pupillary light reflex

Answer 27

1. light sensed by CN II will synapse in pretectal nucleus 2. cells from pretectal nucleus synapse in Edinger-Westphal nucleus 3. preganglionic parasympathetic neurons travel with CN III and synapse in ciliary ganglion 4. post-ganglionic parasympathetic neruons synpse in pupillary constrictor muscle

Question 28

how many neurons are involved in the **pupillary light reflex**?

Answer 28

four

Question 29

corneal reflex

Answer 29

1. Receptors in corneal detect touch or irritation, travel in CN V, and synapse in Trigeminal sensory nucleus or Spinal Trigenminal nucleus. 2. Cells from trigeminal nucleus project to facial nucleus. 3. Neuron in Facial n. will cause eye to blink.

Question 30

lines the innermost part of the eyelids

Answer 30

palpebral conjunctiva

Question 31

lines the outermost part of the eyeball

Answer 31

bulbar conjunctiva

Question 32

where is *superior tarsal m*. and what is its innervation?

Answer 32

superior tarsal m. is located beneath the *levator palpebrae superioris m.* innervated by sympathetic nerves

Question 33

Identify which is a bacterial vs. viral infection.

Answer 33

Question 34

rupture of blood vessels between sclera and bulbar conjunctiva

Answer 34

subconjunctival hemorrhage due to increased intraocular pressure

Question 35

complete ptosis vs. partial ptosis

Answer 35

* **complete ptosis**: destruction of CN III \> paralysis of *levator palpebrae superioris m.* * **partial ptosis**: affects post-ganglionic sympathetic fibers (from T1)\> paralysis of *tarsal muscle m.*

Question 36

Where do the preganglionic fibers to the postganglionic symapthetic fibers (innervating the Tarsal muscle of Muller) originate from?

Answer 36

level of T1

Question 37

fundoscopy

Answer 37

Question 38

scotoma

Answer 38

"area of partial alteration in the field of vision consisting of a partially diminished or entirely degenerated visual acuity that is surrounded by a field of normal – or relatively well-preserved – vision" **optic disk** is area of scotoma

Question 39

important anastamoses

Answer 39

* superficial temporal a. & supraorbital a. * supratrochlear a. & angular a. * lacrimal a. & middle meningeal a. * ethmoidal a. & sphenopalatine a.

Question 41

Answer 41

**central retinal vein occlusion** causes: * hardening of CRA * HTN in CRA \> compresses CRV * hemorrhages * dilated veins

Question 42

Answer 42

**central retinal artery occlusion** * causes: atherosclerosis and embolism * retina appears white * cherry red spot * veins and arteries attenuated

Question 43

components of lacrimal appartus

Answer 43

* lacrimal gland * lacrimal canaliculi * lacrimal sac * nasolacrimal duct

Question 44

secretes lacrimal fluid/tears

Answer 44

lacrimal gland

Question 45

watery physiological saline containing bacteriocidal enzyme lysozyme fluid moistens and lubricates surface of conjunctiva and cornea provides some nutrients and oxygen to cornea

Answer 45

lacrima fluid

Question 46

starts at lacrimal punctum (openng) on lacrimal papilla drains lacrimal fluid from lacrimal lake to lacrimal sac

Answer 46

lacrimal canaliculi

Question 47

dilated superior part of nasolacrimal duct

Answer 47

lacrimal sac

Question 48

conveys lacrimal fluid to inferior nasal meatus

Answer 48

nasolacrimal duct

Question 49

nerves involved in tear production

Answer 49

Question 50

circumferential tissue inside eye composed of **ciliary muscle** and **ciliary processes**

Answer 50

ciliary body

Question 51

secrete aqueous humor which fills anterior and posterior chambers

Answer 51

ciliary processes

Question 52

space between cornea and iris/pupil

Question 53

space between iris/pupil and lens & ciliary body

Answer 53

posterior chamber

Question 54

flow of aqueous humor

Answer 54

1. from ciliary body 2. posterior chamber 3. anterior chamber

Question 55

glaucoma

Answer 55

blockage of Schlemm's canal

Question 56

rupture of blood vessels supplying the anterior eye

Answer 56

hyphema

Question 57

functions of ciliary body

Answer 57

* contraction of ciliary muscles decrease size of ciliary body * reduces tension on suspensory ligament * lens becomes more rounded for near vision