Visual System

Question 1

The aperture or gap that controls the amount of light entering the next chamber of the eye. Size is controlled by the iris.

Answer 1

pupil

Question 2

Bring visual images into sharp focus by acting as a fine adjustment to the cornea. Behind the pupil.

Answer 2

lens

Question 3

Small round window that enables light to enter the eye

Answer 3

cornea

Question 4

A ring of muscles that gives the eye its colour

Answer 4

iris

Question 5

Tough white tissue that covers the eye

Answer 5

sclera

Question 6

How many rods are there?

Answer 6

120 million

Question 7

How many cones are there?

Answer 7

6 million

Question 8

Cones are used to see

Answer 8

light and colour

Question 9

Rods are used to see in the

Answer 9

dark

Question 10

Most of the rods are located in the

Answer 10

periphery

Question 11

Most cones are in the centre or in the

Answer 11

fovea

Question 12

Which cells project laterally or sideways and interconnect the photoreceptors?

Answer 12

horizontal cells

Question 13

Both rods and cones contain special chemicals called

Answer 13

photopigments

Question 14

What do photopigments do?

Answer 14

absorb light and transduce it into neural information

Question 15

What is the response of an on-centre cell?

Answer 15

on response when light is in centre of field, off response when light is in periphery of the field.

Question 16

What is the response of an off-centre cell?

Answer 16

off response when light is in the centre of the field, on response when the light is in the periphery of the field

Question 17

The sensory area detected by a group of photoreceptors that converge onto an individual ganglion cell and contribute to its neural activity is known as?

Answer 17

receptive field

Question 18

What is the colour opponent theory?

Answer 18

Each detector produces 2 colour sensations which also oppose each other (red-green, yellow-blue, black-white)

Question 19

What links the bipolar and ganglion cells?

Answer 19

amacrine cells

Question 20

Bipolar cells project to what cells?

Answer 20

ganglion cells

Question 21

What is the optic nerve made out of?

Answer 21

axons of the ganglion cells

Question 22

The part where two optic nerves cross over each other is called the?

Answer 22

optic chiasm

Question 23

Where does 80% of visual information terminate?

Answer 23

lateral geniculate nucleus

Question 24

what cells is the lateral geniculate nucleus composed of?

Answer 24

magnocellular and parvoocellular cells

Question 25

the superior colliculus is responsible for?

Answer 25

saccadic eye movement

Question 26

The optic tract that doesn't go to the lateral geniculate nucleus branches out to:

Answer 26

suprachiamatic nucleus, pretectum, superior colliculus.

Question 27

A simple cell in the visual cortex has a receptive field (at the retina) that is

Answer 27

Elongated with on and off components (responding best to a stationary line in the correct orientation)

Question 28

A complex cell in the visual cortex:

Answer 28

Responds maximally when a line is anywhere in its receptive field providing it is in the correct orientation

Question 29

A hypercomplex cell responds best to?

Answer 29

a line in a specific orientation and of a certain length

Question 30

We have 2 eyes (left and right) but one visual world. This convergence of visual input is called?

Answer 30

occular dominance

Question 31

The dorsal pathway is where?

Answer 31

parietal lobe

Question 32

the ventral pathway is where?

Answer 32

temporal lobe

Question 33

The dorsal pathway is also known as the

Answer 33

where pathway

Question 34

the ventral pathway is also known as the

Answer 34

what pathway

Question 35

Prosopagnosia is when you can't

Answer 35

recognise faces

Question 36

Simultanagnosia is when you are unable to

Answer 36

put a scene together and make sense of it

Question 37

Someone who has ocular apraxia is unable to

Answer 37

make a systematic scan and has wondering eyes

Question 38

optic ataxia is?

Answer 38

unable to reach for objects

Question 39

someone with associative agnosia can't identify

Answer 39

what

Question 40

someone with appercetive agnosia can't identify

Answer 40

where (man who mistook wife for a hat)

Question 41

Cells in the blobs found in the visual cortex are involved in?

Answer 41

colour perception

Question 42

Orientation detection is first coded by

Answer 42

simple cortical cells

Question 43

The range of electromagnetic energy visible to humans falls between

Answer 43

400 and 750 nm

Question 44

Which cell type responds to high contrast and colour?

Answer 44

P cells

Question 45

Motion information is conveyed by

Answer 45

M cells

Question 46

Four of the six LGN layers contain ?

Answer 46

Parvocellular layers

Question 47

common in older people and the reduced ability of the lens to accommodate is called

Answer 47

presbyopia

Question 48

Myopia is?

Answer 48

unable to see things clearly from far away