Eye

Question 1

describe how the optic cup is formed

Answer 1

neural tube develops into optic vessel
contacts the overlying ectoderm forming the lens placode
ectoderm folds inwards becoming double walled optic cup

Question 2

how are lens vesicles get produced and for what function

Answer 2

folded inwards and pinched off lens placode
induce ectoderm to become lens cornea

Question 3

what is the optic nerve developed from

Answer 3

optic stalk

Question 4

what do the layers of the optic cup develop into

Answer 4

inner to neural retina
outer to pigmented retina

Question 5

what role does the mesenchyme have in eye development

Answer 5

surround optic cup
forms 2 layers above retina

Question 6

name the tunica layers of the eye

Answer 6

outer fibrous tunic
middle vascular tunic
inner nervous tunic

Question 7

What are the parts of the fibrous tunic

Answer 7

Sclera
Cornea

Question 8

What structural components make up the fibrous tunic

Answer 8

Dense collagen tissue

Question 9

What structures make up the vascular tunic

Answer 9

Choroid
Ciliary body
Iris

Question 10

What makes up the nervous tunic

Answer 10

Retina

Question 11

Describe the cornea

Answer 11

Transparent to allow light to enter

Question 12

What is the epithelial layer of the cornea

Answer 12

Have surface squamous epithelium (conjunctiva)

Question 13

What is the sclera

Answer 13

Posterior part of eye

Question 14

Where is the sclera made of

Answer 14

Fibrous connective tissue and elastic fibres

Question 15

What is the function of the sclera

Answer 15

Protect internal structures and maintain eye shape

Question 16

What muscles insert onto the sclera

Answer 16

Extra-ocular muscles

Question 17

What are the layers of the cornea

Answer 17

Epithelium (conjunctiva)
Stroma
Endothelium

Question 18

What is the choroid

Answer 18

Vascular lining at the back of the eye

Question 19

What is the function of the choroid

Answer 19

Nourishes the retina

Question 20

What vascularised the choroid

Answer 20

Ophthalmic artery

Question 21

What is the function of the tapetum lucidum and where is it found

Answer 21

Reflect light back to retina for night vision
(Found in the choroid)

Question 22

Where do the sclera and cornea meet

Answer 22

Corneal-scleral junction

Question 23

Where is the ciliary body found

Answer 23

Between choroid and iris (from of eye)
And at the corneal-scleral junction

Question 24

How does the lens change shape

Answer 24

Ciliary muscle contraction + relaxation

Question 25

Where is the function of suspensory ligaments

Answer 25

Hold ciliary muscles to the lens

Question 26

What Is the function of ciliary epithelium

Answer 26

Secrete aqueous fluid that circulates anterior and posterior chamber of the eye

Question 27

What happens if aqueous fluid in eye doesn’t get absorbed

Answer 27

Glaucoma (high pressure in eye can lead to damage)

Question 28

What makes up the iris

Answer 28

Smooth muscle Collagen fibres Pigment cells

Question 29

What is the function of the pupil

Answer 29

Controls amount of light entering eye

Question 30

What type of smooth muscle is found in the iris and what are their functions

Answer 30

Circular Radial Constrict of dilate the pupil to control amount of light entering eye

Question 31

What is the function of the retina

Answer 31

Convert light to nerve signals

Question 32

What are the layers of the retina

Answer 32

Neural layer Pigmented layer

Question 33

What is is the function of the pigmented layer

Answer 33

Dark so stops light from bouncing around the eye

Question 34

Name the photoreceptor cells and their functions

Answer 34

Rods: for low light vision and black and white Cones: for bright light and colour vision

Question 35

How do signals from photoreceptor cells get to the brain

Answer 35

Through retinal sublayers to ganglions. These axons converge to form optic nerve

Question 36

Name the 3 chambers of the eyes

Answer 36

Anterior Posterior Vitreous

Question 37

What is the function of vitreous humour

Answer 37

Maintains shape of the eyeball and provide nutrients to structures

Question 38

Where does the eye sit in the skull

Answer 38

Bony orbit

Question 39

What is forward facing vision called

Answer 39

Binocular

Question 40

What is side facing vision called

Answer 40

Monocular

Question 41

How does the eye move up, down, left, right

Answer 41

4x recuts muscles

Question 42

How does the eye move around its axis

Answer 42

2x oblique muscles

Question 43

How does the eyeball retract and what is the purpose

Answer 43

Retractor bulbi Protects eye (found in predators)

Question 44

What are the functions of the eyelids

Answer 44

Protects cornea Keeps eye moist

Question 45

What is the nicitating membrane When can it be seen

Answer 45

3rd eyelid (in cats and dogs) When eyeball retracts

Question 46

What is the function of the tear film

Answer 46

Nourishes cornea Keeps eyelid moist

Question 47

Which gland nourishes the cornea (produce tears)

Answer 47

Lacrimal gland

Question 48

Where do tears drain into

Answer 48

Nasolacrimal duct

Question 49

What nourishes the retina in birds and why

Answer 49

Pectern

Question 50

How are bird eye vascularisation different and why is it essential

Answer 50

Less vascularisation, so doesn’t block light entering the retina (unlike humans)

Question 51

What do snakes have to protect the eye

Answer 51

Spectacle (transparent) (Is what leads to eye caps in dysecdysis)