Eyeball

Question 1

what is the eyeball?

Answer 1

a bilateral and spherical organ

Question 2

what does the eyeball house?

Answer 2

houses the structures responsible for vision

Question 3

where does the eyeball lie?

Answer 3

lies in a bony cavity within the facial skeleton – known as the bony orbit

Question 4

anatomically, how can the eyeball be divided?

Answer 4

3 parts:

fibrous, vascular and inner layers.

Question 5

what is the fibrous layer of the eyeball?

Answer 5

outermost layer

Question 6

what does the fibrous layer of the eyeball consist of?

Answer 6

sclera and cornea, which are continuous with each other

Question 7

function of sclera and cornea of fibrous layer?

Answer 7

provide shape to the eye and support the deeper structures

Question 8

how much of the fibrous layer does the sclera make up?

Answer 8

comprises the majority of the fibrous layer (approximately 85%)

Question 9

function of the sclera of fibrous layer?

Answer 9

It provides attachment to the extraocular muscles

Question 10

function of extraocular muscles?

Answer 10

these muscles are responsible for the movement of the eye

Question 11

what is the sclera seen as?

Answer 11

It is visible as the white part of the eye

Question 12

describe the cornea (location)

Answer 12

transparent, and positioned centrally at the front of the eye

Question 13

function of cornea?

Answer 13

Light entering the eye is refracted by the cornea

Question 14

where is the vascular layer found?

Answer 14

The vascular layer of the eye lies underneath the fibrous layer

Question 15

what does the vascular layer consist of?

Answer 15

choroid, ciliary body and iris

Question 16

what is choroid within the vascular layer?

Answer 16

A layer of connective tissue and blood vessels

Question 17

function of the choroid within the vascular layer?

Answer 17

It provides nourishment to the outer layers of the retina

Question 18

what does the ciliary body consist of? (within vascular layer)

Answer 18

Comprised of two parts – the ciliary muscle and ciliary processes

Question 19

what does the ciliary muscle consist of? (within vascular layer)

Answer 19

a collection of smooth muscles fibres

Question 20

what are the ciliary muscles attached to? by? (within vascular layer)

Answer 20

to the lens of the eye by the ciliary processes

Question 21

function of the ciliary body? (within vascular layer)

Answer 21

The ciliary body controls the shape of the lens, and also contributes to the formation of aqueous humor

Question 22

what is the iris? (vascular layer of eye)

Answer 22

A circular structure, with an aperture in the centre (called the pupil)

Question 23

what alters the diameter of the pupil? (vascular layer of eye)

Answer 23

smooth muscle fibres within the iris

Question 24

what are the smooth muscle fibres within the iris innervated by? (vascular layer of eye)

Answer 24

the autonomic nervous system

Question 25

where is the iris situated? (vascular layer of eye)

Answer 25

between the lens and the cornea

Question 26

what does the inner layer of the eye consist of?

Answer 26

the retina

Question 27

what is the retina? (inner layer of eye)

Answer 27

the light detecting part of the eye

Question 28

what is the retina composed of? (inner layer of eye)

Answer 28

2 cellular layers: Neural layer Pigmented layer

Question 29

what does the neural layer consist of? within retina (inner layer of eye)

Answer 29

Consists of photoreceptors; the light detecting cells of the retina

Question 30

where is the neural layer located?

Answer 30

posteriorly and laterally in the eye | within retina (inner layer of eye)

Question 31

where does the pigmented layer lie?

Answer 31

Lies underneath the neural layer

Question 32

what is the pigmented layer attached to? (inner layer)

Answer 32

the choroid layer | CT of vascular - middle - layer

Question 33

what is the function of the pigmented layer?

Answer 33

acts to support the neural layer

Question 34

location of the pigmented layer?

Answer 34

continues around the whole inner surface of the eye | within retina in inner layer of eye

Question 35

within the inner layer of the eye, which layer continues anteriorly? known as?

Answer 35

Anteriorly, the pigmented layer continues but the neural layer does not known as the non visual retina

Question 36

what is the optic part of the retina?

Answer 36

Posteriorly and laterally, both layers of the retina are present (neural + pigmented)

Question 37

what can be viewed during ophthalmoscopy?

Answer 37

The optic part of the retina (posterior + lateral - both layers of retina)

Question 38

what is the centre of the retina marked by?

Answer 38

marked by an area known as the macula

Question 39

what is the appearance of the macula (centre of retina within inner layer)?

Answer 39

yellowish in colour, and highly pigmented

Question 40

what does the macula contain? (centre of retina within inner layer)

Answer 40

a depression called the fovea

Question 41

what does the fovea contain? (within macula, centre of retina within inner layer)

Answer 41

high concentration of light detecting cells

Question 42

what is the fovea responsible for? (within macula, centre of retina within inner layer)

Answer 42

high acuity vision

Question 43

what is the optic disc?

Answer 43

The area that the optic nerve enters the retina

Question 44

what is significant about the optic disc?

Answer 44

it contains no light detecting cells