16-18. Visual system

Question 1

In the visual pathway, info is sent to the visual cortex via the optic nerve and the…

Answer 1

Lateral geniculate nucleus

Question 2

which region is responsible for orientating the eyes/skull towards stimuli?

Answer 2

superior colliculus

Question 3

type of photoreceptors in peripheral retina?

Answer 3

rods

Question 4

which type of photoreceptor has the highest convergence?

Answer 4

rods

Question 5

Name of muscle in anterior eye

Answer 5

cilliary muscle

Question 6

what do the zonule fibres allow

Answer 6

for the lens to be stretched

Question 7

which area in the eye has the highest visual acuity?

Answer 7

fovea

Question 8

where do the blood vessels of the eye originate from?

Answer 8

optic disc

Question 9

what 2 parts are the retina split into?

Answer 9

nasal and temporal

Question 10

which part of the photoreceptors release NT?

Answer 10

pedicle

Question 11

name 4 retinal cells

Answer 11

1. bipolar
2. horizontal
3. ganglion
4. amacrine

Question 12

what is stereopsis

Answer 12

depth perception

Question 13

what 2 visual fields do we have? what do each of them mean?

Answer 13

binocular = using both eyes 
monocular = uses 1 eye

Question 14

describe brief visual pathway overview - 3

Answer 14

1. retina
2. lateral geniculate nucleus of thalamus
3. primary visual cortex

Question 15

where do visual tracts decussate?

Answer 15

optic chiasm

Question 16

nerve coming from the eye

Answer 16

optic nerve

Question 17

what is the full visual field

Answer 17

area which is viewed by both eyes

Question 18

what is the full visual field divided into?

Answer 18

left and right visual hemi-fields

Question 19

what is the binocular visual field?

Answer 19

area of overlap between right and left hemi-fields

Question 20

what is a fixation point?

Answer 20

image which we are focusing on

Question 21

which side of the eye is the nasal retina on?

Answer 21

medial

Question 22

describe stereopsis

Answer 22

comparing the fixation point (which projects onto the fovea) with other points that lie on the retina

Question 23

will far disparities be closer or further away from the fovea?

Answer 23

closer

Question 24

where does the retino-fugal pathway start and stop?

Answer 24

starts at retina

stops at striate cortex

Question 25

which component controls pupillary light constriction? - where exactly in the brain is this?

Answer 25

pretectum - midbrain

Question 26

where is visual info processed

Answer 26

lateral geniculate nucleus of thalamus

Question 27

what is blind sight?

Answer 27

visual which is not dependent on the processing from primary visual areas of the cortex

Question 28

which 2 areas of the brain are thought to be used for blind sight>

Answer 28

1. superior colliculus | 2. amygdala

Question 29

which brain lobe is the striate cortex located?

Answer 29

occipital

Question 30

brodmann's areas for visual processing- which is the primary visual processing area?

Answer 30

17 (v1), 18 and 19

Question 31

in the striate cortex - what is the function of the dorsal stream?

Answer 31

motion processing

Question 32

in the striate cortex - what is the function of the ventral stream?

Answer 32

visual details, face selective cells

Question 33

which cells do we have more of; rods or cones?

Answer 33

rods

Question 34

where are these cells concentrated? i) rods ii) cones

Answer 34

i) periphery | ii) fovea

Question 35

which photoreceptor detects colour?

Answer 35

cones

Question 36

do rod cells have high or low visual acuity?

Answer 36

low

Question 37

describe convergence of rods to ganglions

Answer 37

high

Question 38

describe convergence of cones to ganglions

Answer 38

low

Question 39

in what light setting are rods used?

Answer 39

low lighting

Question 40

how many pigments do cones use - what are they?

Answer 40

3 - blue red green

Question 41

how many pigments do rods use - what are they?

Answer 41

1 - rhodopsin

Question 42

describe wavelength of the following pigments i) blue ii) green iii) red

Answer 42

i) short ii) medium iii) long

Question 43

which region is responsible for orientating the eyes/head towards a visual stimulus?

Answer 43

superior colliculus

Question 44

describe glutamate release and cell polorisation when a photon of light hits a cell

Answer 44

- no release of glutamate | - cell hyperpolarisation

Question 45

what happens to glutamate release and BC activity when: | light inputs onto a photoreceptor directly connected to an ON BC cell

Answer 45

decreased glutamate release BC depolarises - activity increases

Question 46

what happens to glutamate release and BC activity when: | light inputs onto a photoreceptor directly connected to an OFF BC cell

Answer 46

decreased glutamate release BC hyperpolarises - activity decreases

Question 47

describe the highest level of response for on OFF bipolar cell in terms of centre and surround

Answer 47

dark in centre | light in surround