Special Senses: The Eye

Question 1

Sclera

Answer 1

Outer coat layer protects eyeball

Found below conjunctiva

Question 2

Conjunctiva

Answer 2

Thinner layer of tissue that lines the inner of the eyelids and outer surface of the sclera

Question 3

Choroid

Answer 3

Found behind retina and contains blood vessels that help nourish the retina

Question 4

Retina

Answer 4

Sensitive and lines the back of the eye: contains photoreceptors

Made from two layers

1. Pigmented layer; has melanin sheet that has epithelial tissues between choroid and neural layer
2. Neural layer; responsible for transduction

Question 5

Iris

Answer 5

Colour region area under cornea

Controls amount of light enters eyes by adjusting size of pupil

Oculomotor cranial nerves responsible for the contraction of the circular smooth muscles of the iris

Question 6

Pupil

Answer 6

Found under the cornea centre of iris

It is how light enters eyes

Question 7

Cornea

Answer 7

Transparent structure at the front of the eye

Light focusing structure

Question 8

Lens

Answer 8

Found behind the iris

Helps to focus light on the retina

Question 9

Fovea

Answer 9

Found at the centre of the macula which processes clear vision

Question 10

Optic discs

Answer 10

Contain optic nerves that carry visual messages from retina to anterior chamber containing aqueous humour fluid produced in the eye

Question 11

Where is the aqueous humour fluid produced

Answer 11

By the ciliary body above the lens

Question 12

Rods

Answer 12

Sensitive to low light intensity

Found in the retina

Question 13

Cones

Answer 13

Sensitive to only high intensity light

Concentrated in the fovea

Question 14

Steps of the visual pathway

Answer 14

1. Nerve impulse arise in ganglion cells
2. Pulses conducted along optic nerve through optic chains and optic tract to thalamus
3. Impulses from thalamus extend to the visual area in the occipital lobe of the cerebral cortex