The orbit and the Eye

Question 1

Describe the papyrcea

Answer 1

medial wall containing sinuses

Question 2

Describe the function of the orbital rim

Answer 2

thick wall, good at protecting the eye unless there is exophthalmos or piercing object

Question 3

What is the risk with a blowout fracture?

Answer 3

Damage the infraorbital neurovascular bundle; resulting in a sensory deficit

Question 4

What causes a blowout fracture?

Answer 4

Pressure increase inside the orbit rises dramatically, inferior or medial bones will fracture to release pressure

Question 5

What are the four components of the eyelids?

Answer 5

Outer skin
Inner conjunctiva
Eyelashes
Glands

Question 6

What is the function of the tarsal plate ?

Answer 6

Maintains shape and contains meibomian glands

Question 7

What is the role of meibomian glands?

Answer 7

secrete lipids

Question 8

What is the innervation pattern of obicularis oculi?

Answer 8

facial nerve

Question 9

What is the result of obicularis oculi contraction?

Answer 9

closure of the eye

Question 10

What does occulomotor nerve palsy result in?

Answer 10

Not be able to open your eye- ptosis

Question 11

What is the limbus?

Answer 11

Corneoscleral junction

Question 12

Which layers of the eye are continuous?

Answer 12

Cornea and sclera

Question 13

What nerve is responsible for production of tears?

Answer 13

Parasympathetic CN 7 (facial)

Question 14

What is the function of tears?

Answer 14

Wash over eye - lubrication

Question 15

Describe the sclera?

Answer 15

White fibrous layer

Question 16

Describe the function of the cornea?

Answer 16

refraction

Question 17

What is the uvea?

Answer 17

Vascular middle layer

• iris
• ciliary body
• choroid

Question 18

What is the function of the iris?

Answer 18

Control pupil diameter

Question 19

What is the function of the ciliary body?

Answer 19

Controls iris, shape of lens, secreted aqueous humour

Question 20

What is the function of the choroid?

Answer 20

Nutrition and gas exchange

Question 21

Why does the choroid appear black?

Answer 21

Vasculature and melanin

Question 22

What is the function of the retina?

Answer 22

Photosensitive inner layer containing rods and cones

Question 23

What is the anterior chamber of the eye ?

Answer 23

Infront of lens; between cornea and iris

Contains aqueous humour

Question 24

What is the posterior chamber of the eye?

Answer 24

Behind lens

Contains vitreous humour

Question 25

Where is a common location for floaters?

Answer 25

Posterior segment of the eye

Question 26

List the steps in circulation of aqueous humour?

Answer 26

1. Ciliary body - smooth muscle and blood vessels, ciliary processes secrete aqueous humour 2. Aqueous circulates - within posterior chamber, nourishes lens 3. Aqruous passes though pupil - into anterior chamber and nourished cornea 4. Aqueous reabsorberd - into scleral venous sinus (canal of schlemm) - at iridocorneal angle

Question 27

List the layers of the retina from posterior to anterior?

Answer 27

1. Photoreceptors 2. Ganglion cells 3. Axons of ganglion cells

Question 28

What is the optic disc?

Answer 28

Point of CN II formation only point of exit/entry for blood vessels and axons of CN II blind spot

Question 29

What is the macula?

Answer 29

Area with greatest density of cones

Question 30

What is the fovea?

Answer 30

Centre of the macula Depression, 1.5mm diameter Area of most acute vision

Question 31

What does complete interruption of flow in a retinal artery branch/vein cause?

Answer 31

Loss of area of visual field corresponding to the area of ischaemia

Question 32

What causes monocular blindness?

Answer 32

Complete interruption of flow from the central artery or vein

Question 33

Which extrinsic muscles of the eye are innervated by the oculomotor nerve?

Answer 33

Medial Rectus Superior Rectus Inferior Rectus Inferior Oblique

Question 34

Which extrinsic muscle of the eye is innervated by the abducens nerve?

Answer 34

Lateral rectus

Question 35

Which extrinsic muscle of the eye is innervated by the trochlear nerve?

Answer 35

Superior oblique

Question 36

Describe the function of the lateral rectus?

Answer 36

Abduction of the eye

Question 37

Describe the function of the medial rectus?

Answer 37

Medial movement of the eye

Question 38

Describe the function of the superior rectus?

Answer 38

Up and in

Question 39

Describe the function of the inferior rectus?

Answer 39

Down and In

Question 40

Describe the function of the superior oblique?

Answer 40

Down and out

Question 41

Describe the function of the inferior oblique?

Answer 41

Up and out