Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Vision Science 2 w/ Shwartz text > EXAM 1 - Week 1 to 3 > Flashcards

EXAM 1 - Week 1 to 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What occurs when RPE starts to disengrate?

A

Photoreceptors cannot recycle, thus dying off

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

What is photopic vision?

A

Where cones predominatly function

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

What gives the retina its duplex property?

A

Rods and Cones

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

What is mesopic?

A

Combination of cones and rods function

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

What is scotopic?

A

Where rods predominantly function

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

Where is the opsin found in rods and cones?

A

In the outer segment

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

What photoreceptor sheds its discs

A

Rods

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

What is the maximum absorption (not sensitivity) of rod wavelength?

A

Around 500nm - Green color

Note: Rods are most sensitive to Violet color

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

What is sensitivity of cone wavelenght?

A

S-420 - Blue
M-530 - Blue - Green
L - 560 -Yellow - Green

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

What is the Rod sensitivity in nm?

A

498

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

What is the physiological dark adapt time?

A

35 minutes

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

How many photons can a rod be stimulated for vision to occur?

A

100’s of rods

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

How many photons are needed to stimulate a rod?

A

1 photon

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

In order by wavelength, put the photoreceptor in order.

A

Blue, Rod, Green and Red

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

True or False, you can detect one photon of light.

A

False. You personally cannot but your rod can

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

Is there an area where there are no photoreceptors?

A

Yes, the optic disc

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

What do we have more of rods or cones in the eye?

A

Rods

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

Where is the peak of cones?

A

Outside the fovea, 20 to 30 degrees

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

What is predominantly found in the fovea?

A

L and M cones

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

What is more dominant between L and M cones?

A

Varies. From 1 to 1 or 16 to 1 (M to L)

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

What is Dr. Cameron’s research with Zebra fish being conducted?

A

AMD

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

What is the lowest threshold for a Cone response, in regards to Dark Adaptation?

A

10 minutes

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

When do rods start functioning in regards to Dark Adaptation and when is the threshold met?

A

Don’t start till 10 minutes and 20 minutes after there is a threshold

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

What is the photochromatic interval?

A

Difference between rod plateau and cone plateau interval

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

At 35 minutes, what is the sensitivity of the human eye in dark adaption?

A

100,000 times more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the 5 areas where Dark Adaption can be effected?

A

Light Intensity - Brighter the room, the longer it takes to recover
Light Duration
Wavelength - What wavelength are rods sensitve to (Violet)
Location
Rhodopsin regeneration - slower regeneration and takes a while

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 4 sub-titles for the parting the curve graph?

A

Note: background must be red and stimulus is green
1 - Dark Light
2 - Square Root Law
3 - Weber’s law - slope will be the same for scoptic and photopic
4 - Saturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is a quanta in the nervous system?

A

1 packet of a neurotransmitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

You pt. a rod monochromat, has asked for advice regarding tinted lenses. You should advise a darkly tinted lens of which color?

A

Red lenses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What color as a background will activate both rods and cones for light adaptation?

A

Green will be the background and Yellow be the test spot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where does neural nose occur for rods?

A

Dark light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Where is the threshold start to pass the neural noise area?

A

square root law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

where is traditional vision occurring?

A

Weber’s law - Most of this occurs here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where is saturation occurring?

A

Saturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How many ganglion cells will 10 rods connect to?

A

1 ganglion cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How many cones will connect to a ganglion cell?

A

5 cones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is Ricco’s law?

A

Looking at spatial summation, its the AREA you look at.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What happens when a threshold has been achieved?

A

An action potential occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the type of summation that is rated over time?

A

Temporal Summation
Note: If you see a flash within 100ms, you will only see one flash in the Scotopic
Note: If you see any flash over 10m/s, you will see more than one flash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the stiles crawford effect?

A

Light has to strike a cone perpendicularly, while for rods it doesn’t matter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the sclera largely consist of?

A

Collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How much refraction power does the cornea provide?

A

2/3 of refractive power entering the eye (40D)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What happens to the lens when you would like to increase the power of the lens?

A

Decrease the curvature of anterior lens surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What part of photoreceptors does adaption for transmitting the neural signal?

A

Innermost PR cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What type of photopigment is located in Rods and Cones?

A

Rods - Rhodopsin

Cones - Opsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Where are rods located the most?

A

Outside of the fovea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

How many discs is a rod made of?

A

600 to 1000

Note: Disc membrane is seperate from the plasma membrane of the cell except at the base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

When do rods shed?

A

During the day, specifically the evening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is the name of the specialized terminal of a rod?

A

Spherule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Where are cones predominantly located?

A

20 to 30 degrees outside the fovea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

True or False. The plasma membrane of the photoreceptor is Continous with the disc membrane of the Cone.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Where are the cell bodies of bipolar cells, HC, AC, Interplexiform cells and Mueller cells located in the retina?

A

Inner Nuclear Layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the % of Small midget GC’s in the eye?

A

80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the % of Large Parasol GC’s in the eye?

A

10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

How many degrees away is the optic disc away from the fixation point?

A

15 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the primary target for the optic tract?

A

LGN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Which layers receive input from the ipsilateral eye?

A

2, 3, 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How many layers are there for the ventral Magnocellular layer?

A

2

59
Q

How many layers are there for the dorsal Parvocellular layer?

A

4

60
Q

Which cortical area do LGN synapse?

A

V1 or Broadmann Area 17

61
Q

Which PR is more prone to being more hypersensitive?

A

Rods.

Note: rods are more sensitive to light

62
Q

What is the photoreceptor in order by wavelength smallest to Largest?

A

S, Rod, M, and L

63
Q

What is the visual acuity in the Scotopic system?

A

20/200

64
Q

When phagocytosis of discs doesn’t occur, what damaging disease can occur?

A

Retinitis Pigmentosa

65
Q

How many molecules of rhodopsin molecules are contained in a rod?

A

10,000

66
Q

What wavelength region are most likely to be absorbed by rhodopsin?

A

507nm

67
Q

True or False. A lower threshold = high sensitivity

A

True

68
Q

What is the photochromatic interval?

A

Pt. dark adapts and where both PR’s regenerate

69
Q

What is the Purkinje Shift?

A

Lighting conditions that change from scotopic to photopic

Note: 507nm to 555nm

70
Q

In regards to Dark Adaption, how would light effect your ability to dark adapt?

A

Dim light: cause dark adaption faster

Bright light: cause dark adaption slower

71
Q

In regards to Dark Adaption, How much time does it take a cone plateau duration?

A

10 minutes

72
Q

In regards to wavelength, what color are humans sensitive to and that has a lower threshold, with a high sensitivity?

A

Violet

73
Q

True or False. Ganglion cells are always spontaneously firing?

A

True

74
Q

True or False. Amacrine cells are always firing?

A

False. Only when light has been stimulated, only then an action potential will be displayed.

75
Q

What type of neuron displays action potentials?

A

Amarcine cells

Note: When light goes off, an action potential will get excited.

76
Q

If a photoreceptor hyperpolarizes a horizontal cell synapsing on it will?

A

Hyperpolarize

77
Q

During light adaption, when being outside on a sunny day, amount of light is increased by many thousands but the appearance ________ changes

A

Never

78
Q

In regards to spatial summation, Under photopic conditions, what three visual contradictions manifest to maximize visual resolution at the expense of sensitivity?

A

Contrast, Visual Acuity and Visual Resolution

Note: Photopic system is poor under spatial summation but excellent under spatial resolution

79
Q

What are the 2 types of GC cells?

A

M (parasol = Alpha) cells and P (midget = Beta) cells

80
Q

What is the % of Parasol cells in the retina?

A

5% of all GC.

Note: They are transient, they will work quickly and die off quickly

81
Q

What is the % of Midget cells in the retina?

A

90% of all GC

82
Q

What is the time for scotopic temporal summation?

A

100 m/s

Note: within 100 m/s you will have 2 responses but higher than 100 will give you one

83
Q

What GC does not require a PR but can receive light on their own?

A

Melonopsin Cells

84
Q

What is the function of the super chiasm nucleus?

A

Rhythm maker to keep homeostasis.

85
Q

What is the temporal summation in the photopic system?

A

10 m/s

86
Q

In the photopic luminosity curve, how is the stimuli rated radiometrically and photometrically?

A

Radiometrically - equal

Photometrically - different

87
Q

What is the basic unit of photometry?

A

lumen

Note: Luminous power is non-directional

88
Q

What is the formula for lumens?

A

lumens = (luminous efficiency) (680 lumens/W)(W)

89
Q

What does Abney’s law of additivity state?

A

Adding the values of each wavelength

90
Q

What is luminance?

A

Light coming off a surface

91
Q

Is there more convergence on a Alpha cell or Beta cell?

A

Alpha cell

92
Q

What is illuminance?

A

Amount of light falling on a surface

93
Q

What is the resting potential in front of the eye?

A

6 mV

94
Q

What disease can an EOG find out?

A

Best’s disease

95
Q

What is the arden ratio?

A

Ratio of light rise to the dark trough expressed as a %

96
Q

What would be considered an abnormal Arden ratio?

A

165 to 180%

97
Q

For an ERG, what does a Ganzfeld dome provide?

A

A sphere that illuminates the retina evenly

98
Q

In regards to ERG components, which wave provides the largest ERG wave?

A

B wave - Mueller cells and On bipolar cells

99
Q

When you see reduced Photopic and Scotopic ERG’s and reduced amplitude, what type of disease can be considered?

A

Retinitis Pigmentosa

100
Q

If you a find a pt. with rod levels that are normal but the cones are lost but a little functional?

A

Cone Dystrophy

101
Q

If you find a pt. with no scotopic system and photopic system is some what functional, what health issues do you think this individual has?

A

Complete CSNIB

102
Q

A pt. is tested and you find the scotopic system is normal but there is no detectable flicker and NO functional photopic system, what issues does this pt. have?

A

Rod Monochromat

103
Q

Which test would you conduct if you would like to find out how much progression has occurred in Glaucoma Progression?

A

mfERG

104
Q

With VEP, what changes and stays the same, WAVELENGTH OR LATENCY?

A

W - does not change
L - changes

NOTE: VEP tests the brain stimulation

105
Q

What is the positive peak for VEP?

A

P100

Note: there are 2 negative peaks, N75 and N135

106
Q

CHAN ET. AL found what 2 distinct issues with the ERG test and VEP test?

A

ERG - Reduced

VEP - Reduced Amplitude but Increased Latency

107
Q

Which region of the retina do Bipolar cells synapse to ganglion cells?

A

IPL

108
Q

Which region of the retina do PR’s synapse to Horizontal cells?

A

OPL

109
Q

True or False. PR’s create a action potential.

A

False. They create a GRADED POTENTIAL

110
Q

What major chemical mechanism is used when recreating rods?

A

Recoverin

111
Q

What is rhodopsin made of?

Hint: Think of two compounds

A

Opsin and chromophore

112
Q

What is the name, when PR’s are connected to HC’s?

A

Sign-Conserving synapse

113
Q

What occurs to PR’s, Glutemate and Bipolar cells, when dark conditions are present?

A

PR’s - Depolarize
Glutamate - Increase release
BC’s - Excited

114
Q

What occurs to PR’s, Glutemate and Bipolar cells, when Light conditions are present?

A

PR’s - Hyperpolarize
Glutamate - Decrease release
BC’s - Inhibited

115
Q

Do BC’s provide an action potential?

A

No

116
Q

Do AC’s provide an action potential?

A

Yes

117
Q

Do GC’s provide an action potential?

A

Yes

118
Q

What protein does transducin activate?

A

Phosphodieserase

119
Q

Do HC’s provide and action potential?

A

No

120
Q

What type of cone bipolar cell has an increased spatial summation and decreased spatial resolution?

A

S cone

121
Q

In light, what happens to Calcium channels?

A

Close

122
Q

In Dark, what happens to Calcium channels?

A

Open

123
Q

As an individual reaches the presbyopia stage, what usually occurs to the crystalline lens?

A

Lens becomes opaque and Cataracts form

124
Q

What usually gives the retina its reddish color?

A

Choroid and RPE

Note: Retina is transient

125
Q

True or False. Albino individuals, there choroid can be seen, via fundus photo.

A

True

126
Q

You have a pt. whose OPL and INL are splitting, what health problem can this be?

A

Degenerative Retinoschisis

127
Q

A pt. shows profound signs of a feathery like tuft and has 20/20 vision. What could be the white like issue?

A

Myelinated nerve fibers

128
Q

Your pt. complains of a vision lost in certain areas of their visual field. You conduct your tests and diagnose a cherry red spot and you believe what major vasculature vessel is effected?

A

Central Retinal Artery

129
Q

Most of UVC absorption occurs at what structure of the eye?

A

Cornea

130
Q

Most of UVA and UVB absorption occurs at what structure of the eye?

A

Crystalline lens

131
Q

In the absence of phagocytosis, what debilitating disease can occur to the visual system?

A

Retinitis Pigmentosa

Rods that shed their discs accumulate and thus overpowering the retina and killing off many rods

132
Q

True or False. Rod Monochromats can get it anytime during their lifetime.

A

False. It is congenital.

133
Q

What is perimetry?

A

Visual field test

134
Q

What is static perimetry and Kinetic perimetry?

A

Static - pt. pushes button when a stimulus occurs

Kinetic - stimulus remains constant but the stimulus is moved around

135
Q

When the plots for perimetry are connected, what type of diagnoses test is this called?

A

Isopter

136
Q

In perimetry, what is the most commonly used unit?

A

Apostilb (asb)

Note: Visual field test gives you result of 10 will equal 1000asb. However, when 21 is given, which is poor number compared to 10, will give you an asb of 79.4

137
Q

What is worst, UVA or UVB?

A

UVA - it penetrates the dermis and can cause melanoma

Note: UVB - can penetrate the epidermis and can cause wrinkles and possibly melanoma

138
Q

What type of colored lens will help in the aid of protecting from UVB and UVA radiation?

A

Yellow - long pass filter, which blocks blue light

139
Q

What diagnostic test will detect Best’s Disease?

A

EOG

140
Q

What is the benefit of mfERG, compared to ERG?

A

mfERG - can do an entire scan of the retina, where as ERG must be specific

141
Q

To find outer retinal diseases, what test can be preformed?

A

ERG

142
Q

You have a pt. that is non-responsive and you would like to find their ability to contrast sensitivity and maybe even get their VA. What diagnotic test would you preform?

A

VEP - Use this test, when you get pts. who act like that you don’t exist!!!!

Note: It is crucial pt. look at a fixating chart

143
Q

Damage to the choriocappilaris and Bruch’s membrane , can lead to what debalitating disease which occupies the fovea?

A

ARMD - Either wet (leaky blood) or dry (no vascular hemmoraging)

144
Q

When a person lives in the Northwest or in Canada, they generally don’t get enough light. What disorder can occur and what is a new measure to correct this?

A

Disorder: SAD
Measure: Give them light

Vision Science 2 w/ Shwartz text (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions