Eye

Question 1

What are the three layers of the eye

Answer 1

Corneoscleral coat, uveal tract and retina

Question 2

What is the cornea

Answer 2

A transparent anterior extension of the sclera

Question 3

What does the uveal tract consist of

Answer 3

Anteriorly - iris and ciliary body

Posteriorly - vascularised choroid coat

Question 4

What does the retina consist of

Answer 4

Layers of nerve cells, their processes, support cells and on the outside, a layer of pigmented epithelium

Question 5

What allows the lens to change shape

Answer 5

Its elasticity

Question 6

What does the change in shape of the lens allow

Answer 6

Accommodation for near vision

Question 7

What is in front of the lens

Answer 7

Anterior and posterior chambers

Question 8

What fills the anterior and posterior chambers

Answer 8

Aqueous humor

Question 9

What lies posterior to the lens

Answer 9

The vitreal cavity

Question 10

What fills the vitreal cavity

Answer 10

Vitrius humor

Question 11

Structure of vitrous cavity

Answer 11

Avascular and gelatinous due to collagen fibres and hyaluronic acid

Question 12

What is the conjuctiva

Answer 12

A thin, transparent mucous membrane

Question 13

What lines the conjunctiva

Answer 13

Stratified columnar epithelium with goblet cells, and has a lamina propria of loose connective tissue

Question 14

Where does the conjunctiva run from/to

Answer 14

The corneosclearal margin and reflects over the inner surface of the eyelids

Question 15

Composition of the cornea

Answer 15

Outer layer of thin non-keratinised stratified squamous epithelium sitting on a thin layer of collagen (Bowman’s membrane) composed of randomly orientated, condensed thin collagen fibrils

Question 16

What is the stroma

Answer 16

Many layers of precisely orientated hydrated collagen

Question 17

What is between the layers of the cornea

Answer 17

Corneal fibroblasts

Question 18

What is on the inside of the cornea

Answer 18

Layer of endothelium sitting on a layer of meshwork collagen called Duscemet’s membrane

Question 19

What causes a Kaiser-Fleischer ring

Answer 19

An accumulation of copper in Duscemet’s membrane

Question 20

What is the sclera

Answer 20

A tough coat of collagen and elastic fibres defining the globe

Question 21

What attaches to the sclera

Answer 21

The tendons of the extraocular muscles

Question 22

What does the ciliary body contain

Answer 22

Smooth muscle

Question 23

What is the function of the smooth muscle in the ciliary body

Answer 23

It releases tension on the zonular fibres, during near vision, allowing the lens to round-up

Question 24

How is excess fluid drained from the anterior chamber

Answer 24

Via the canal of Schlemm

Question 25

What causes glaucoma

Answer 25

Drainage of the anterior chamber of the eye is not adequate

Question 26

What is the iris composed of

Answer 26

Loose connective tissue with a layer of pigmented epithelium on its posterior surface

Question 27

What cell is found within the iris

Answer 27

Melanocytes

Question 28

What is the function of the smooth muscle within the iris

Answer 28

Changes the iris diameter

Question 29

Where are the sphincter pupillae muscles found

Answer 29

Near the tip of the iris

Question 30

Function of sphincter pupillae muscles

Answer 30

Under parasympathetic innervation - constrict the pupil

Question 31

Function of dilator pupillae muscles

Answer 31

Under sympathetic innervation - open the pupil

Question 32

What does the ciliary body attach to and how

Answer 32

To the lens by a series of zonular fibres

Question 33

How does aqueous humor flow

Answer 33

From the anterior chamber to the posterior chamber

Question 34

What is the lens

Answer 34

A transparent, biconvex structure made up of lens fibres

Question 35

What are contained within the lens fibres

Answer 35

Proteins called crystalins

Question 36

What covers the lens anteriorly

Answer 36

Outer connective tissue capsule and a layer of simple cuboidal epithelium

Question 37

What is the retina

Answer 37

A complex, thin layer of nervous tissue lining the inner eye

Question 38

What structures are within the retina

Answer 38

Rods and cones

Question 39

What do rods conatin

Answer 39

Rhodopsin - a light sensitive pigment

Question 40

What is contained within cones

Answer 40

One of three epsin pigments - sensitive to either red, green or blue light

Question 41

What structure predominates away from the fovea

Answer 41

Rods

Question 42

What lies at the centre of the retina

Answer 42

The fovea

Question 43

What is at the centre of the fovea

Answer 43

The foveola

Question 44

What happens to the retina at the foveola

Answer 44

It thins and becomes avascular

Question 45

What structure is found at the foveola

Answer 45

Cones

Question 46

What covers the cones at the foveola

Answer 46

The outer plexiform layer

Question 47

What is the optic disc

Answer 47

The site where the axons of the retinal ganglion cells exit the eye to form the optic nerve

Question 48

What must the nerves pass through to create the optic nerve

Answer 48

The sclera

Question 49

What does the optic disc lack

Answer 49

Photoreceptors

Question 50

What are the openings in the sclera that the axons pass through known as

Answer 50

Lamina cribrosa

Question 51

What is the optic disc also known as

Answer 51

The blind spot