Lecture 11 - Vision

Question 1

from which range of wavelengths of light is the visual system sensitive to?

Answer 1

380-740nm

Question 2

which pathway in the brain is for spatial location (where)?

Answer 2

dorsal

Question 3

which pathway in the brain is for object identification (what)?

Answer 3

ventral

Question 4

how many cell types in the retina, how many nuclear layers and how many synaptic layers?

Answer 4

7, 3, 2

Question 5

name the 3 nuclear layers of the retina

Answer 5

outer nuclear layer, inner nuclear layer and ganglion cell layer

Question 6

name the types of cells found in the retinal outer nuclear layer

Answer 6

photoreceptors - rods and cones

Question 7

name the types of cells found in the retinal inner nuclear layer

Answer 7

horizontal, bipolar and amacrine cells

Question 8

name the type of glial cell found in the retina

Answer 8

muller cell

Question 9

name the 2 synaptic layers of the retina

Answer 9

outer plexiform and inner plexiform

Question 10

in the outer plexiform synaptic latyer of the retina there are synaptic connections between which 3 types of cells?

Answer 10

photoreceptors, horizontal and bipolar cells

Question 11

in the iner plexiform synaptic layer of the retina there are synaptic connections between which 3 types of cells?

Answer 11

bipolar, amacrine and ganglion cells

Question 12

order the layers of the retina from outermost to innermost: outer nuclear, inner nuclear, ganglion, outer plexiform, inner plexiform

Answer 12

outermost: outer nuclear, outer plexiform, inner nuclear, inner plexiform, ganglion : innermost

Question 13

which type of cells span the entire thickness of the retina?

Answer 13

muller cells

Question 14

in which synaptic layer of the retina are there on and off connections?

Answer 14

inner plexiform

Question 15

name the range of light level in log cd/m2 that rods allow us to see light in

Answer 15

-6 to 1

Question 16

name the range of light level in log cd/m2 that cones allow us to see light in

Answer 16

-3 to 10

Question 17

the range of light in which rods are active is known as what?

Answer 17

scotopic range

Question 18

the range of light in which cones are active is known as what?

Answer 18

photopic

Question 19

the range of light in which cones and rod activity overlaps is known as what?

Answer 19

mesopic range

Question 20

in which segments of rods/cones does phototransduction occur in? what is also contained within these segments?

Answer 20

outer segments, opsins

Question 21

which photoreceptor is responsible for vision in dim light (darkness, moonlight, candlelight)?

Answer 21

rods

Question 22

which photoreceptor is responsible for vision in daylight/ bright sun/starlight?

Answer 22

cones

Question 23

which photoreceptors have high spatial acuity/high resolution images, low sensitivity and a narrow angle of coverage? what type of vision is this?

Answer 23

cones, central vision

Question 24

which type of photoreceptors have low resolution images/poor spatial acuity, high sensitivity and aids in motion detection? what type of vision is this?

Answer 24

rods, peripheral vision.

Question 25

short wavelength cones detect which colour of light? long wavelength? medium wavelength?

Answer 25

short - blue long - red medium - green

Question 26

photoreceptors trigger which two types of cell which creates a glutamatergic response?

Answer 26

bipolar and horizontal

Question 27

what sort of size receptive field does the fovea have? what about the periphery?

Answer 27

fovea is small, periphery large

Question 28

midget (p) cells are the basis for the what pathway and they recognise which two things?

Answer 28

form and colour

Question 29

parasol cells (m) detect which 2 things and are part of which pathway?

Answer 29

motion and distance, dorsal

Question 30

in which location in the brain does the division between the dorsal and ventral pathway become anatomically evident?

Answer 30

lateral geniculate nucleus of the thalamus

Question 31

S cones connect to S-cone biplar cells - which colour is this detecting? what about L and M cones - what colour?

Answer 31

S = blue L+M = yellow

Question 32

in a B/Y bistratified ganglion cell where does the excitatory input come from? where does the inhibitory input come from?

Answer 32

excitatory from S cone bipolar cells inhibitory from L+M cone bipolars

Question 33

what does the superior colliculus in the retinotectal tract aid?

Answer 33

eye movements

Question 34

what does the pretectum aid reflexes of?

Answer 34

pupil

Question 35

in the retinohypothalamic tract what is the hypothalamus responsible for?

Answer 35

circadian rhythms

Question 36

the left visual field falls on which nasal retina?

Answer 36

left

Question 37

what is the name of the location at which optic nerves from both eyes meet?

Answer 37

optic chiasm

Question 38

at the lateral geniculate nucleus how many layers in total? how many are parvo pathways at the top? how many are magno pathways at the bottom?

Answer 38

6 layers, top 4 are Parvo pathways, bottom 2 are Magno on each eye

Question 39

in the lateral geniculate nuclei for both eyes, give the pattern of contralateral and ipsilateral layers starting from 6 going down to 1

Answer 39

c, i, c, i, i, c

Question 40

to which cortex do LGN neurons project to

Answer 40

striate/6th

Question 40

what is the name of the band of myelinated axons runnning parallel to the surface of the cortex along the calcarine fissure of the occipital lobe?

Answer 40

stria of gennari

Question 41

main input from LGN is to which layer?

Answer 41

4

Question 42

in which layer of the striate cortex are cells monocular? what are they in the other layers?

Answer 42

layer 4, binocular

Question 43

what is the name of columns in which the striate cortex is organised? do they alternate between left and right eye?

Answer 43

ocular dominance columns, yes

Question 44

for which type of cells (simple or complex) is the hubel and wiesel model for?

Answer 44

simple

Question 45

which 2 types of cells in V1 receptive fields perform length summation?

Answer 45

complex and simple

Question 46

which type of cells in V1 receptive field have inhibitory flanks on the ends of the receptive field?

Answer 46

hypercomplex

Question 47

which type of cells in V1 receptive field have separate on and off subregions?

Answer 47

simple

Question 48

which type of cells in V1 receptive fields are line detectors?

Answer 48

simple

Question 49

which type of cells in V1 receptive fields are motion detectors?

Answer 49

complex

Question 50

which type of cells in V1 receptive fields are angle detectors?

Answer 50

hypercomplex

Question 51

which 3 types of cell can work together to decompose the outlines of a visual image into short segments forming the basis of simple and complex object recognition?

Answer 51

simple, complex and hypercomplex