Sleep and VIsion Flashcards

1
Q

The ____ Muscles are essential for accommodation

A

Ciliary

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

Cones in the retina form synapses with which of the following cell types?

A

Bipolar Cells

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

What is responsible for the lack of photoreceptors at the optic disc and the consequent blind spot?
Correct!

A

It is the location where blood vessels and ganglion cell axons leave the eye

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

The brightest light we can see is about _____ times as intense as the dimmest light we can see

A

10 Billion

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

Why is it best to look slightly off center to see a distant, dim star?

A

Rods are absent in the fovea and numerous in the retina periphery and are sensitive to dim light

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

Cells in the primate LGN have receptive fields that

A

Concentric

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

In _____ cells, light falling in the center of the cell causes excitation, and light falling in the surround cause inhibition

A

On-center/off-surround

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

Rod receptors are _____ by the presence of a light stimulus

A

Hyperpolarized

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

One of rod vision is less acute because

A

Rods have higher convergence onto retinal ganglion cells

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

Which best describes the order of information flow out of the retina

A

Photo receptor, bipolar cell, retinal ganglion cell

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

Layer of neurons

A

Retina

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

Turning light into neural signals in a process called

A

Transduction

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

Bending of light rays

A

Refraction

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

Outer layer of eye

A

Cornea

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

Light passes through the cornea is further refracted by the lens which

A

Changes its shape to fine tune that image on the retina

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

Nearer images to come into focus on the retina process is called

A

Accomodation

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

Difficulty seeing distant objects

A

Myopia

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

How does myopia develop?

A

If the eyeball is too long, causing the cornea and lens to focus images in front of the retina rather than on it

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

Movement of eye is controlled by

A

Ocular muscles

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

Where does the first stages of visual process occur?

A

In the Retina-200-300 micrometer thick

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

Photoreceptors?

A

Sensory neurons that detect light

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

Where do rods and cones photoreceptors release neurotransmitters?

A

into synapses on bipolar cells

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

What do bipolar cells connect with

A

ganglion cells

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

What do ganglion cells form

A

The optic nerve

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

Horizontal cells

A

make contacts among the receptor cells and bipolar cells

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

Amacrine cells

A

Contact both the bipolar and ganglion cells

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

What do the rods, cones, bipolar, and horizontal cells generate

A

only graded local potentials, DO NOT produce action potentials

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

What do ganglion cells conduct

A

Action potentials

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

What are rod based systems

A

Scotopic system (darkness) very sensitive works well in low light. Insensitive to color- cant tell colors apart at night

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

Convergence

A

Lots in the scotopic system b/c info from many rods converges onto each ganglion cell

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

Cones based system

A

Less sensitive than rods, have higher threshold before they respond. Requires more light to function

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

Photopic system

A

differential sensitivity to wavelengths enabling our color vision, has less convergence

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

Where are light particles detected?

A

Stack of discs

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

Only a fraction of light that strikes the cornea actually reaches the retina?

A

True

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

Photoreceptors in the dark release

A

Neurotransmitters onto bipolar cells

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

When light hits photopigment in the photoreceptor it triggers a cascade of chemical reactions

A

Hyperpolarize the cell, released less neurotransmitter onto bipolar cells

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

Stimulation of rhodopsin by light

A

Hyperpolarize the rods- for rods and cones the size of hyperpolarizing photoreceptors potential determines how much less neurotransmitter will be released

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

Handling of different light intensities by different receptors with some low thresholds (rods) and other with high thresholds (cones)

A

Range fractionation

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

Sharpness of vision

A

Visual acuity

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

Where is the highest acuity

A

In the fovea, more densely packed with cones

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

Rods provide high sensitivity with

A

limited acuity

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

Cones provide

A

High acuity with limited sensitvity

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

In the fovea light

A

reaches the cones without having to pass through blood vessels and other layers of cells

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

Optic disk is on the

A

nasal side of the fovea, where blood vessels and ganglion cells axons leave the eye

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

Why is the optic disk our blind spot?

A

There are no photoreceptors

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

Ganglion cells in each eye produce

A

Action potentials, conduct along their axons to send visual information to the brain. These axons make up the optic nerve

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

Optic nerve cross the midline at the

A

Optic chiasm

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

Half the retina toward your temple project

A

its axons to its own side of the brain

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

Where do the majority of retinal ganglion cells send their optic tract axons

A

Superior coliculus in the midbrain- coordinates rapid movement and controls pupils response to light levels

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

Most axons on the optic tract terminate on cells in the

A

Lateral geniculate nucleus (LGN)- visual part of the thalamus

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

Primary visual cortex is important for

A

Depth perception

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

Spot where nothing is perceived- person cannot consciously perceive visual cues

A

Scotoma

53
Q

Sensory cells consists of the stimulus features that

A

Excited or inhibits the cells

54
Q

Both rods and cones photoreceptors release the synaptic transmitter

A

Glutamate- light always hyperpolarizes

55
Q

On bipolar cells glutamate is

A

Inhibitory

56
Q

Glutamate is excitatory to

A

Off- center bipolar cells

57
Q

Bipolar cells release

A

Glutamate- always depolarizes ganglion cells

58
Q

When light is turned on

A

on center bipolar cells depolarize (excite) on center ganglion cells

59
Q

When light is turned off

A

off center bipolar cells depolarize (excite) off center ganglion cells

60
Q

The entire receptive field of a bipolar cell is

A

Concentric

61
Q

Sensory receptor cells inhibit the reporting of information from neighboring receptor cells

A

Lateral inhibition

62
Q

What is free running

A

maintaining its own personal cycle in the absence of external cues

63
Q

T/ F removing various endocrine glands had little effect on the free running rhythm of rats

A

True

64
Q

Suprachiasmatic nucleus (SCN)

A

A small region of the hypothalamus above the optic chiasm that is the location of a circadian clock

65
Q

Electroencephalography (EEG)

A

provide a way to define, describe, and classify levels of arousal and states of sleep

66
Q

Fully awake alert person is a mixture of what?

A

low amplitude waves with many relative fast frequencies

67
Q

Beta activity also known as

A

desynchronized EEG

68
Q

Non REM sleep stage 1

A

slowing of the heart rate and relaxation of the muscles, eyes may roll back slowly

69
Q

Stage 2

A

Defined by waves 12-14 Hz called sleep spindles, occur in periodic bursts and by K complexes

70
Q

Stage 3 (SWS- Slow wave sleep)

A

Appearance of large amplitude very slow waves called delta waves

71
Q

REM sleep (paradoxical sleep)

A

small amplitude, high frequency activity similar in many ways to the pattern on an awake person, except eyes moving back and forth across eyelids

72
Q

Atonia

A

Complete absence of muscle tone

73
Q

During REM motor neurons are

A

Inhibited, and is accompanied by irregular breathing and pulse rate as in wakefulness, also experience vivid dreams in this state

74
Q

Stage 3 we are mostly

A

most deeply asleep and the pituitary gland releases growth hormone

75
Q

When do night terrors occur

A

Sudden arousal from stage 3 SWS

76
Q

Infant sleep is characterized as

A

Shorter sleep cycles than adults, also showing large perception of REM sleep. Half of sleep in the first two weeks of life is REM

77
Q

What stage is the most dramatic decline in sleep

A

Stage 3 sleep 60 year old people spend only half as much time in stage 3 than they did when at age 20. 90 years old stage 3 sleep has disappeared

78
Q

Photoreceptors are depolarized in the absence of

A

Light, and constantly release glutamate in the dark

79
Q

Temple side

A

Ipsilateral

80
Q

Nasal side

A

Contralateral

81
Q

The circadian rhythm is synchronized by

A

Light

82
Q

Lesion of the SCN will

A

Eliminate circadian rhythm

83
Q

Retinal ganglion cells form

A

the retinohypothalamic pathway, carries light information from the eye to the SCN

84
Q

The relaxed mind exhibits

A

Alpha rhythm, regular oscillation at the frequency 8-12 hz

85
Q

Energy Conservation theory

A

Reduces energy consumption during a time when it is more difficult or dangerous to look for food

86
Q

Restorative function

A

Materials used up during waking hours, rebuilt or restored of proteins

87
Q

Forebrain system

A

Generates SWS

88
Q

Brainstem system

A

Activates forebrain to wakefullness

89
Q

Pontine system

A

Triggers REM sleep

90
Q

Hypothalamic system

A

Coordinates the other three

91
Q

The forebrain generates

A

Slow wave sleep

92
Q

Reticular Formation Wake up the Forebrain

A

Acts on basal forebrain

93
Q

Reticular Activating System (RAS)

A

Together, the forebrain and reticular formation seem to regulate SWS and wakefulness

94
Q

Locus coeruleus

A

Responsible for REM sleep

95
Q

Orexin neurons in the hypothalamus project to other sleep systems centers

A

Basal forebrain, reticular formation and the locus coeruleus

96
Q

What does orexin do?

A

Determines wakefulness, non- REM sleep, or REM sleep

97
Q

Interfering with hypocretin signaling leads to

A

Narcolepsy- People that frequent intense sleep attacks- Do not go through SWS before REM sleep

98
Q

Sleep onset insomnia

A

Difficulty in falling asleep and can be caused by situational factors, shift work, or jet lag

99
Q

Sleep-maintenance insomnia

A

Difficulty in staying asleep and may be caused by drugs or neurological and psychiatric factors- especially evident in respiratory disorders

100
Q

Muscle spindles respond to

A

Muscle stretch and respond during lengthening

101
Q

Golgi tendon organs are sensitive to

A

Tension during contraction

102
Q

Passive stretching of a muscle

A

Cause activation of the muscle spindle

103
Q

Spindle will synapse on

A

alpha motor neuron in the spinal cord

104
Q

Cerebellum is important for

A

Making corrections

105
Q

Pyramidal (or corticospinal) tract

A

Looks like upside down pyramid- - Comes from primary motor cortex. Name coming from the pyramidal shape of the tract in the medulla- collecting axons from entire motor cortex

106
Q

Extrapyramidal tract

A

Modulating reflexes and online tuning of movement- Name reflects the fact this it is outside the pyramidal tract

107
Q

Pyramidal Tract (corticospinal tract)

A

Sends motor commands from the brain to the spinal cord- Pass through the pyramids of the medulla.

108
Q

The lateral tract (90% of fibers)

A

Cross at the medulla and controls movement of the contralateral limbs- controls the other side of the body

109
Q

The ventral portion (10% of fibers)

A

Crosses in the spinal cord and controls trunk movement (controlled together)- does not cross over until synapses the alpha motor neurons

110
Q

Pyramidal Motor Tract

A

Many signals originate in upper motor neurons in the primary motor cortex (M1)- send synapses down- Make synapses on alpha motor neurons (also called lower motor neurons) in the spinal cord

111
Q

Lower limbs

A

Dorsally and medially

112
Q

Face

A

Vental and lateral

113
Q

Hand area

A

In between

114
Q

Large muscles group

A

Much smaller, Lips, tongue, and hands- have the most control

115
Q

M1 cells

A

Change firing rate according to direction of the movement

116
Q

Extrapyramidal system

A

Basal ganglia- important for movement and learning (Habit learning dictated by basal ganglia) are a group of structures in the middle of the brain- Plays a role in action selection and onset as well as the execution of learned movement

117
Q

The cerebellum

A

Has more neurons in itself than the rest of the brain-consistent wiring pattern, computer of the brain)- is important for motor learning and helps to regain movement as they are happening- makes movements smooth and more accurate- alcohol consumption can affect this

118
Q

Premotor cortex

A

In front of motor cortex more on the lateral side- translating sensory information to appropriate motor goals and plans

119
Q

Supplementary motor cortex

A

Mainly on the medial surface of the cerebral hemispheres lies on top actions that are well-learned, and actions stimulated by a stimulus in the environment- well-learned actions

120
Q

The premotor cortex is important in

A

Translating sensory information into action

121
Q

The SMA is

A

Is important for representing internal action goals and for action initiation

122
Q

What does LTM have

A

Vast capacity but is subject to forgetting

123
Q

Doe not deteriorate over time but is it interfered with by other events that occur before or after their formation

A

Memory tract

124
Q

The process from retrieving info from LTM can cause

A

Memories to become unstable and susceptible to disruption or alteration

125
Q

The return of memory trace to stable long-term storage after recall

A

Reconsolidation

126
Q

Synaptic plasticity

A

Research has focused on learning-related changes in the strength of the synapsis

127
Q

T/F we dont grow new neurons in our brain but can grow new axon collaterals- more effective having branch out and broader reach

A

True

128
Q

Three housing conditions

A

Standard condion (SC)
Impoverished condition (IC)
Enriched condition (EC)