Anatomy

Question 1

What two parts of the eye are mentioned as being extremely thin and are often affected in an orbital blowout fracture?

Answer 1

the medial wall of the orbit & orbital floor

Question 2

Where does a fracture zygoma tend to rotate?

Answer 2

rotate medially towards the floor of the orbit

Question 3

What assists with preventing the spread of infection from superficial (periorbital cellulitis) to deep (orbital cellulitis)?

Answer 3

orbital septum

Question 4

Fibres of which muscle allow for screwing up the eye?

Answer 4

orbicularis oculi

Question 5

What is the muscle that raises the upper eyelid?

Answer 5

tendon of levator palpebrae superioris

Question 6

What attaches eyelid to orbital rim?

Answer 6

medial palpebral ligament

Question 7

What is the iris covered by?

Answer 7

the translucent, avascular cornea

Question 8

Where do tears go in blinking?

Answer 8

lacrimal lake then puncta

Question 9

What is the lower eyelid lined by?

Answer 9

conjunctiva

Question 10

Where is the conjunctiva reflected off the sclera and onto the internal aspect of the eyelid?

Answer 10

the conjunctival fornix

Question 11

What does the conjunctiva form?

Answer 11

forms a defensive barrier to foreign bodies penetrating deep to it into the orbit

Question 12

What is the limbus?

Answer 12

corneoscleral junction

Question 13

What produces tears and what supplies this?

Answer 13

lacrimal gland

parasympathetic supply from CNVII

Question 14

What is the superior end of the nasolacrimal duct?

Answer 14

lacrimal sac

Question 15

What carries tears to the inferior meatus of the nasal cavity?

Answer 15

nasolacrimal duct (tear duct)

Question 16

What are the nasal and temporal corneal reflections used to track clinically?

Answer 16

used clinically to track the symmetry of bilateral eye positions/movements

Question 17

Name the two parts to the outer layer.

Answer 17

1. the sclera (protective/attachment for extraocular muscles)
2. the cornea (provides ~ 2/3rds of the eyes refractive power)

Question 18

Name the 3 parts of the middle layer (the uvea).

Answer 18

1. the iris (control of pupil diameter)
2. the ciliary body (control of the iris, the shape of the lens & the secretion of aqueous humour)
3. the choroid (nutrition & gaseous exchange for the other layers)

Question 19

What is the inner retina composed of?

Answer 19

photosensitive & composed of many layers

Question 20

What is the space between the cornea and the iris and what does it contain?

Answer 20

anterior chamber

contains humour

Question 21

Where is the vitreous body and what does it contain?

Answer 21

posterior segment

contains gel to apply pressure to hold retina to choroid

Question 22

What is the vitreous body a common location of?

Answer 22

floaters

Question 23

Where is the posterior chamber?

Answer 23

between iris and vitreous body

Question 24

What is clouding of the lens?

Answer 24

cataracts

Question 25

Where is iridocorneal angle?

Answer 25

anterior chamber

inferior

Question 26

Where is the aqueous reabsorbed?

Answer 26

reabsorbed into the scleral venous sinus (Canal of Schlemm) at the iridocorneal angle

Question 27

Raised intra-ocular pressure can cause what?

Answer 27

ischaemia of the retina

Question 28

What is the area of most acute vision: greatest density of cones?

Answer 28

the fovea centralis in the macula

Question 29

What does the fundus consist of?

Answer 29

retina + macula + fovea centralis + optic disc

Question 30

What forms at the optic disc?

Answer 30

CN II forms from all the axons leaving the retina

Question 31

Where does the internal carotid artery enter?

Answer 31

the carotid canal in the temporal bone

Question 32

What do nasal cavity branches contribute to?

Answer 32

Kiesselbach’s area

Question 33

What does this describe: an artery with insufficient anastomoses to maintain viability of the tissue supplied if arterial occlusion occurs?

Answer 33

an end artery

Question 34

What vessels are responsible for red eye in flash photography?

Answer 34

ciliary arteries and veins of uvea

Question 35

What is the only point of entry into/exit from the retina for blood vessels & the axons of CN II?

Answer 35

optic disc

Question 36

The “blind spot” of the visual field corresponds to what?

Answer 36

optic disc

Question 37

Complete interruption of flow of the central artery (end artery) or vein leads to what?

Answer 37

monocular blindness

Question 38

Complete interruption of flow in a retinal artery branch/”branch” retinal vein leads to what?

Answer 38

loss of an area of visual field corresponding to the area of ischaemia

Question 39

Are there photoreceptors in the optic disc?

Answer 39

No

Question 40

List the layers of the retina from posterior to anterior.

Answer 40

1. photoreceptor cells
2. the ganglion cells
3. the axons of the ganglion cells

Question 41

Light from objects in the right visual field is processed by what?

Answer 41

left primary visual cortex

Question 42

Light from objects in the lower visual field is processed by what?

Answer 42

lower part of primary visual cortex

Question 43

How many skeletal muscles does the eye have?

Answer 43

7

Question 44

How many oblique muscles?

Answer 44

2 (superior and inferior)

Question 45

How many rectus muscles?

Answer 45

4

Question 46

Which muscle is the pulley of the superior oblique?

Answer 46

trochlea

Question 47

Where do the rectus muscles all originate from?

Answer 47

common tendinous ring attached to the bones surrounding the optic canal

Question 48

Where do the rectus muscles all insert into?

Answer 48

the sclera just posterior to the cornea

Question 49

Lateral rectus is supplied by which nerve?

Answer 49

CN6 (abucens)

Question 50

Superior oblique is supplied by which nerve?

Answer 50

CN4 (trochlear)

Question 51

All other muscles are supplied by which nerve?

Answer 51

CN3 (oculomotor)