Block 10 > mono: functional retina > Flashcards

mono: functional retina Flashcards

(105 cards)

Study These Flashcards
1
Q

The retina encodes __________ into __________

A

Radiant energy into neural signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 10 retinal layers?

A
  • RPE
  • photoreceptors
  • external limiting membrane
  • outer nuclear layer
  • outer plexiform layer
  • inner nuclear layer
  • inner plexiform layer
  • ganglion cell layer
  • nerve fiber layer
  • internal limiting membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What layer of the retina contains cell bodies of rods and cones?

A

Outer nuclear layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What layer of the retina is the location of synapses between rod spherules and cone pedicles and the dendrites of bipolar and horizontal cells?

A

Outer Plexiform Layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What layer of the retina contains cell bodies of the muller cells, bipolar cells, amacrine cells, and horizontal cells?

A

Inner nuclear layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What retinal layer is the location of the synapse between bipolar, ganglion and amacrine cells?

A

Inner Plexiform Layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What retinal layer contains ganglion cell bodies?

A

Ganglion cell layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What retinal layer is composed of axons of ganglion cells?

A

Nerve Fiber Layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the function of the RPE?

A

Maintains health of the retina by providing nutrients and metabolites from the choriocapillaris, removes waste products.

Absorbs light.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is the RPE not the retinal layer closest to incoming light?

A

If the RPE was in front, it would absorb all of the incoming light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Ganglion cells have receptive fields that are composed of a center and a surround. The center will either respond with _________ or _________, and the surround will manifest the ___________ sign

A

Excitation or inhibition

Opposite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Two types of ganglion cell receptive fields:

A

On-center, Off-surround

Off-center, On-surround

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is spontaneous activity with ganglion cell receptive fields?

A

Even when a spot of light is not shining on the receptive field, the cell spontaneously generates action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Depending on its location, a stimulus positioned within a neuron’s receptive fields can either __________ or ___________ its discharge rate

A

Increase or decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The light that falls on a receptive field’s center has the ________ effect of light falling on the surrounding area of the receptive field

A

Opposite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

For an On-Center, Off-Surround receptive field, how will a small light located in the center impact frequency of action potentials?

A

Increase frequency of action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

For an On-Center, Off-Surround receptive field, how will a small light located in the surround area impact frequency of action potentials?

A

Reduce frequency of action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

For an On-Center, Off-Surround receptive field, how will a large light completely covering the center field impact frequency of action potentials?

A

A very large increase in frequency of action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

For an On-Center, Off-Surround receptive field, how will a large light located over the entire receptive field impact frequency of action potentials?

A

The response by the receptive field is about the same as if there were no stimulus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do spatially antagonistic ganglion cells respond to diffuse illumination?

A

NOT well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

For an On-Center, Off-Surround receptive field, how will a sine-wave grating impact frequency of action potentials?

A

Bright bar of sine-wave grating will fall on the excitatory center and increase frequency of action potentials

Dark bar will fall on the inhibitory surround increasing the frequency of action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When is frequency of action potentials highest for an On-Center, Off-surround receptive field?

A

Highest when the light spot fills the entire On-center.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Light spot size that covers the entire On-center, Off-surround receptive field is similar in action potential response to what?

A

Spontaneous activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

For an Off-Center, On-Surround receptive field, how will a small light located in the center area impact frequency of action potentials?

A

Reduces frequency of action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
For an Off-Center, On-Surround receptive field, how will a small light located in the surround area impact frequency of action potentials?
Increases frequency of action potentials
26
Where are photopigments located?
Outer segment of rods and cones
27
Photopigments are composed of two elements, what are they?
Chromophore (11-cis retinal) ## Footnote Opsin
28
Chromophore is responsive to __________
Light
29
Opsin determines the ___________________ of the photopigment
absorption profile
30
Rods and cones have a resting membrane potential of _________
-50 mV ## Footnote typical resting membrane potential -70 mV
31
When photoreceptors are exposed to light they _____________ rather than ___________. The potential goes from ________ to ________
Hyperpolarize rather than depolarize ## Footnote -50 mV to -70 mV
32
The degree of photoreceptor hyperpolarization is related to the ___________________
intensity of stimulus
33
Dark current: In the dark, sodium ions (Na+) flow through ion channels into the _____________________ which produces the slight depolarization of -50 mV
Rod outer segment
34
The absorption of light by rhodopsin initiates a series of events that results in the blockage of ______ channels and the result is what?
Na+ ## Footnote Result is hyper polarization of the outer segment
35
When unbleached, retinal is in the ______________ state
11-cis state
36
Process of Phototransduction (4 Steps)
1. Absorption of a quantum of light transforms the retinal molecule from 11-cis to the all-trans isomer 2. All-trans retinal activates transducin which activates phosphodiesterase (PDE) 3. PDE breaks down cyclic GMP (cGMP) into ordinary GMP 4. A decrease in cGMP leads to the closing of rod outer segment Na+ channels which causes hyper-polarization
37
When rod photoreceptors are in the dark, they are ____________ and release ___________ that can either excite or inhibit ________ cells
Depolarized and release glutamate that can either excite or inhibit bipolar cells
38
When rod photoreceptors are exposed to light, they become _______________ and stop releasing ____________
Hyper-polarized ## Footnote Glutamate
39
Each horizontal cell receives input from many cones, so its receptive field is _________
Large
40
Two main classes of horizontal cells:
H1 cells ## Footnote H2 cells
41
H1 Cells receive input from?
Primarily M- and L-cones, small input from S-cones
42
H2 cells receive input from?
Primarily S-cones. Little input from M- and L-cones
43
Horizontal cells, like photoreceptors, show __________ responses not action potentials
Graded
44
Because photoreceptors and horizontal cells both hyperpolarize in response to light, the synapses connecting them are referred to as _____________ synapses
Sign-conserving
45
What cells are the first retinal cells to display spatial antagonism?
Bipolar cells
46
Like photoreceptors or horizontal cells, bipolar cells __________ action potentials
Do not generate
47
Bipolar cells can be classified in a few different ways, what are they?
On-center or off-center ## Footnote Midget or diffuse
48
On-center bipolar cells are characterized by the ___________ synapse that they make with photoreceptors in the ___________________ layer
Invaginating ## Footnote Outer plexiform layer
49
On-center bipolar synapse with ganglion cells in the ____________ of the _______________ layer
Inner sublayer with inner plexiform layer
50
Off-center bipolar cells are characterized by the _______________ synapse that they make with photoreceptors in the ______________ layer
Flat synapse ## Footnote Outer plexiform layer
51
Off-center bipolar synapse with ganglion cells in the _____________ of the _______________ layer
Outer sublayer of the inner plexiform layer
52
For on-center bipolar cells, glutamate is _____________ causing _______________
Inhibitory causing hyper-polarization
53
For an on-center bipolar cell, a reduction of glutamate causes _______________ of the bipolar cell
Relative excitation (depolarization)
54
For off-center bipolar cells, glutamate is ___________ causing _____________
Excitatory causing depolarization
55
For an off-center bipolar cell, a reduction of glutamate causes _____________ of the bipolar cell
Relative inhibition, hyperpolarization
56
Midget bipolar cells have __________ dendritic trees
Less extensive
57
Midget bipolar cells have ___________ receptive fields than diffuse bipolar cells
Smaller
58
In the fovea and mid-peripheral retina, midget bipolar cells manifest input from a single ______ or _______ cone. What may this help contribute to?
M- or L-cones ## Footnote High levels of acuity
59
In the peripheral retina, the receptive fields centers of midget bipolar cells receive input from ____________ photoreceptors. What does this contribute to?
More than one ## Footnote Reduced acuity seen in the peripheral retina
60
What forms the receptive field center of a midget bipolar cell?
A single M- or L-cone
61
What contributes to the surround area of a midget bipolar cell?
H1 horizontal cells
62
Because H1 horizontal cells receive input from both M- and L-cones, midget cells manifest ___________ center and surround spectral sensitivities, creating ______________
Different ## Footnote Color opponency
63
Do S cones synapse with midget bipolar cells?
No
64
S-cones communicate with their own distinct class of bipolar cells, _________________
S-cone bipolar cells
65
Diffuse bipolar cells have __________ dendritic trees, and ___________ receptive fields compared to midget bipolar cells.
Extensive ## Footnote Larger
66
The receptive field of diffuse bipolar cells is formed by ________________ M- and L-cones.
5 to 10
67
Do diffuse bipolar cells manifest color opponency?
No
68
Bipolar cells that receive input from rods are unable to synapse with ____________ directly
Ganglion cells
69
What do rod bipolar cells use as intermediaries to get signals to ganglion cells?
Amacrine cells
70
Amacrine cells can synapse with both _______ and _________ cone bipolar cells and ganglion cells.
ON and OFF
71
How do amacrine cells respond?
Briefly and transiently
72
What cells are the first retinal neurons to display action potentials?
Amacrine cells
73
Two types of amacrine cells
Small-field ## Footnote Wide-field
74
Small-field amacrine cells spread vertically across __________________
Several strata
75
Wide-field amacrine cells are confined to __________
One strata
76
Do action potentials decay over time?
No
77
Do graded potentials decay over time?
Yes
78
Why is it important for ganglion cells to produce action potentials?
So that their signal make it all the way to the LGN
79
3 main types of ganglion cells
Midget ganglion cells ## Footnote Parasol ganglion cells ## Footnote Small bi-stratified ganglion cells
80
Midget ganglion cells are aka ____________________
Retinal parvo cells
81
Midget ganglion cells constitute _______ % of foveal and non-foveal ganglion cells
70%
82
On-center midget bipolar cells synapse with __________________
On-center midget ganglion cells
83
Off-center midget bipolar cells form synapses with ______________
Off-center midget ganglion cells
84
Foveal midget ganglion cells receive input from ________ midget bipolar cells
One
85
Foveal Midget ganglion cells center is formed by __________ —— leading to _______ spatial summation and _________ spatial resolution
Only one cone ## Footnote Limited ## Footnote High
86
Peripheral midget ganglion cells receive input from ______________________
Multiple midget bipolar cells
87
Peripheral midget ganglion cells center is formed by ___________________ —— leading to __________ spatial summation and __________ spatial resolution
Multiple cones ## Footnote Increased ## Footnote Decreased
88
Parasol ganglion cells are aka _____________
Retinal mango cells
89
Parasol ganglion cells have ___________ dendritic trees and synapse with ______________
Large ## Footnote More than one diffuse bipolar cell
90
Multiple diffuse bipolar cells will compose the receptive field center of parasol ganglion cells. Parasol cells are thought to have _____________ high-frequency resolution
Reduced
91
On-center diffuse bipolar cells synapse with?
On-center parasol ganglion cells
92
Off-center diffuse bipolar cells synapse with
Off-center parasol ganglion cells
93
Parasol cells manifest a ____________ response
Transient
94
Rods contribute to both _________ and ___________ cells but their contribution to _______________ is significantly stronger
Midget and parasol ## Footnote parasol cells
95
S-cone bipolar cells synapse with __________________ ganglion cells
Small bi-stratified ganglion cells
96
The receptive fields of Small bi-stratified ganglion cells have an on-center that is formed exclusively by _________________
S-cones input
97
Small receptive field centers show a _________________ sensitivity function
Narrow, sharp peak
98
Large receptive field centers show a ___________________ sensitivity function
Broader, flatter peak
99
Retinal prosthetics can provide some vision for patients who suffer from diseases that affect the ____________________
Photoreceptors
100
After leaving the eye, ganglion cell axons travel to what 3 locations?
LGN ## Footnote Superior colliculus ## Footnote Pulvinar
101
Midget ganglion cell axons synapse and form the _________ retinogeniculate pathway
Parvo
102
Parasol ganglion cells synapse and form the __________ retinogeniculate pathway
Magno
103
Bistratified ganglion cells synapse and form the __________ retinogeniculate pathway
Konio
104
What retinal cells produce action potentials?
Amacrine cells ## Footnote Ganglion cells ## Footnote APAG
105
What retinal cells possess graded potentials?
Photoreceptors ## Footnote Horizontal cells ## Footnote Bipolar cells
Block 10
flashcards
Decks in class (32)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions