Special Senses 2

Question 1

What are the three main layers of the eye?

Answer 1

Outermost (Corneoscleral coat), Middle (Uveal tract) and Innermost (Retina)

Question 2

What is the cornea?

Answer 2

A transparent anterior extension of sclera

Question 3

What does the uveal tract consist of?

Answer 3

Iris and ciliary body anterior and vascularised choroid coat posteriorly

Question 4

What does the Retina consist of?

Answer 4

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

Question 5

What is a biconvex lens?

Answer 5

Is elastic to allow it to change shape in order to permit accommodation for near vision

Question 6

What are the chambers in front of the lens filled with?

Answer 6

Aqueous humor

Question 7

Posterior to the lens, is a larger virtual cavity filled with?

Answer 7

Vitrous humor

Question 8

Where does the cornea sit?

Answer 8

On the bowman membrane

Question 9

What is the storma of the cornea?

Answer 9

Many layers of hydrated collagen

Question 10

What is on the inner layer of the cornea?

Answer 10

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

Question 11

What is the sclera?

Answer 11

A tough coat of collagen and elastic fibres defining the globe

Question 12

What attaches to the sclera?

Answer 12

Tendons of the extraocular muscles

Question 13

What is the ciliary body?

Answer 13

Contains smooth muscle that during near visions, relates tension on the zonuar fibres allowing the lens to round-up due to its natural elasticity

Question 14

What is the iris?

Answer 14

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

Question 15

What does the iris contain?

Answer 15

Melanocytes

Question 16

What happens to the eyes if there is a lot of melanocytes?

Answer 16

Brown eyes

Question 17

What happens to the eyes if there is not a lot of melanocytes?

Answer 17

Blue eyes

Question 18

What changes the diameter in the iris?

Answer 18

Smooth muscle

Question 19

Where are the sphincter papillae fibres found?

Answer 19

Near the tip of the iris

Question 20

Where is the excess fluid from the anterior chamber drained?

Answer 20

Canal of Schlemm into blood vessles

Question 21

What results when drainage from the anterior chamber is not adequate?

Answer 21

Glaucoma

Question 22

What is a transparent spherical structure that is made up of lens fibres?

Answer 22

Lens

Question 23

What is the lens packed with?

Answer 23

Crystallins

Question 24

What is the lens covered with anteriorly?

Answer 24

Outer connective tissue capsule and a layer of simple cuboidal epithelium

Question 25

What way do the lens fibres run?

Answer 25

Anterior to posterior

Question 26

What is the retina?

Answer 26

Thin layers of nervous tissue lining the inner eye

Question 27

What do the rods do in the retina?

Answer 27

Predominate away from the fovea but are absent in the fovea

Question 28

What is found in rods?

Answer 28

Pigment

Question 29

Where does the fovea lie in the retina?

Answer 29

At the centre of the optical axis on the retina

Question 30

What is at the centre of the fovea?

Answer 30

Foveola

Question 31

What is only found in the foveola?

Answer 31

Cones

Question 32

What is known as the blind spot?

Answer 32

Optic disc

Question 33

What does the optic disc lack?

Answer 33

Photoreceptors

Question 34

What is infront of the lens?

Answer 34

Anterior and posterior chambers

Question 35

What lies posterior to the lens?

Answer 35

The virtual cavity

Question 36

What is the conjuctiva?

Answer 36

A thin, transparent mucous membrane

Question 37

What lines the conjuctiva?

Answer 37

Stratified squamous epithelium with goblet cells

Question 38

What is between the layers of the cornea?

Answer 38

Corneal fibroblasts

Question 39

Function of the sphincter papillae muscles?

Answer 39

Under parasympathetic innervation - constrict the pupil

Question 40

Function of dilator papillae muscles?

Answer 40

Under sympathetic innervation - open the pupil

Question 41

What does the ciliary body attach to and how?

Answer 41

To the lens by a series of zonular fibres

Question 42

What do rods contain?

Answer 42

Rhodopsin

Question 43

What happens to the retina at the foveola?

Answer 43

It thins and becomes avascular

Question 44

What covers the cones at the foveola?

Answer 44

The outer plexiform layer

Question 45

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

Answer 45

Lamina cribrosa