Brainscape's Knowledge GenomeTM

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


See full index

NEUR-210 > Exam 2 > Flashcards

Exam 2 Flashcards

1
Q

What are lesion studies?

A

Examining how damage disrupts function –> localization of function

Micro: small, isolated lesions produced experimentally in animals

Macro: studying behavior in humans after damage due to accident, stroke, tumor, etc.

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

Limitations of lesion studies

A

Essentially case studies; don’t study the effects on distal regions

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

Magnetic Resonance Imaging (MRI)

A

Form of neuroimaging

Uses the magnetic properties of protons in the brain to look at structure and function in a non-invasive way

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

How does proton movement work in an MRI?

A

Protons align in the presence of a strong magnetic field –> an MRI applies magnetic pulses to generate local magnetic fields within the tissue

Protons in different tissues take different amounts of time to relax back out of alignment after a magnetic pulse –> this shows up in different grayscale shades on an MRI

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

What can an MRI reveal?

A

Structural imaging of different shapes in the brain, white vs. gray matter, volume and thickness of tissue, and integrity of fiber tracts

Structure can relate to behavior

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

How can we study how structure seen in MRI relates to behavior?

A

Voxel-based morphometry or voxel-based lesion-symptom mapping

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

How can we analyze white matter pathways (connections and projections within the CNS)?

A

Diffusion tensor imaging (DTI) or diffusion spectrum imaging (DSI)

Both methods measure the diffusion of water molecules in myelinated axons and give a fractional anisotropy (FA) score

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

What does the fractional anisotropy (FA) score mean?

A

Used to determine differences in myelination and associated behaviors

High scores mean water molecules are restricted, indicating a high level of myelination

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

How can we directly measure brain activity?

A

Inserting electrodes into neurons and using electrode arrays to measure voltage changes

Using an EEG via the scalp to measure voltage changes

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

How can we indirectly measure brain activity?

A

Examining oxygenated blood-flow-related signals (PET of fMRI) (neuroimaging)

Examining magnetic fields produced by neural activity (MEG) (recording)

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

Magnetoencephalography (MEG)

A

Recording method of indirectly measuring brain activity on a macro level; measures currents via measuring tiny magnetic fields; better spatial resolution than EEG

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

Electroencephalography (EEG)

A

Recording method of directly measuring brain activity on a macro level; measures electrical activity of neurons through currents that can be picked up at the scalp with electrode sensors; interpreted through ERP graphs

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

Advantages of MEG and EEG (ERP)

A

Excellent temporal resolution in milliseconds

Most direct method of measuring online brain processing

Applicable to a wide range of participants

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

Disadvantages of MEG and EEG (ERP)

A

Only measures at a cortical level

Poor relative spatial resolution (MEG&raquo_space; EEG)

Difficult to localize the source of changes

Takes many trials to see patterns

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

All methods of studying the brain! (8)

A
  • lesion studies
  • drug studies
  • behavioral studies
  • recording studies (single-unit, EEG, MEG)
  • neuromodulation (opto-, chemo-, TMS, tDCS)
  • neuroimaging (MRI, DTI, PET, fMRI)
  • genetic studies
  • clinical studies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Types of resolution

A

Spatial (space) and temporal (time)

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

Levels of spatial resolution

A
  • subcellular
  • cellular
  • circuits
  • groups of neurons
  • systems
  • behavior
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Functional MRI (fMRI)

A

Neuroimaging method

Uses a strong gradient magnetic field to take advantage of different magnetic resonances of oxyhemoglobin and deoxyhemoglobin molecules

Indirectly measures neural activity during task performance by giving blood oxygenation level-dependent (BOLD) signal

Highlights functional connectivity

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

Advantages of fMRI

A

High spatial resolution

Online viewing of activity

Viewing of full brain rather than just the cortex

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

Disadvantages of fMRI

A

Poor temporal resolution

Indirect measure of activity

Individual differences make it difficult to see persistent patterns

Participant limitations

Expensive

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

Functional connectivity

A

The correlation between resting-state activity in different regions of the brain; thought to highlight regions that are structurally and functionally connected

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

Neuromodulation methods

A

Micro: electrical and chemical stimulation, genetic manipulations

Macro: magnetic stimulation (TMS), direct or alternating current (tDCS)

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

Micro neuromodulation through electrical stimulation

A

Implanted electrode transmits current into neuron/brain

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

Micro neuromodulation through chemical stimulation

A

Transmission of agents known to excite neurons (for example, kainic acid is a glutamate agonist)

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

Micro neuromodulation through genetic manipulation

A

Optogenetics: genetic manipulations make cells responsive to light

Chemogenetics or DREADDs: genetic manipulations make cells responsive to chemicals

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

Macro neuromodulation

A

Transcranial magnetic stimulation (TMS) and direct current stimulation (tDCS)

Cause temporary lesion or beneficial excitation depending on frequency and type

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

Advantages of macro neuromodulation

A

Temporary effects

Can cause both excitation or inhibition

Relatively inexpensive (tDCS)

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

Disadvantages of macro neuromodulation

A

Poor spatial resolution and localization

Alternative methods needed to assess underlying effect

Participant limitations

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

Behavioral studies

A

Micro: cells and molecules
Macro: animals/humans

Can measure performance on tasks, use standardized measures in research and diagnosis (behavioral, cognitive, or achievement), designed to measure functions to understand underlying deficits

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

Standardized tests

A

Measure achievement (reading, spelling, math) and behavior (depression, anxiety, attention)

Used to place individual performance in the context of the “average” population

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

Advantages of behavioral studies

A

Non-invasive, relatively inexpensive

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

Disadvantages of behavioral studies

A

Multiple potential underpinnings to complex behaviors

Need alternative method to asses underlying effect

Participant limitations

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

How can we use animal models in research?

A
  • genetic modulation
  • developmental studies
  • modeling brain abnormalities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Advantages of animal models

A

Higher level of control

Higher degree of manipulation in the system

Molecules to systems in one model

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

Disadvantages of animal models

A

Impossible to model all human behaviors in animals

System doesn’t perfectly parallel human brain

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

Sensation

A

The transduction of an external stimulus into an electrical signal (light, sound, touch)

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

Perception

A

The point at which a stimulus enters conscious awareness in the brain

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

Sensory receptors

A

Specialized cells that detect a particular category of stimulus

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

Sensory transduction

A

Process by which sensory stimuli are transduced into graded receptor potentials

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

Receptor potential

A

The graded electrical potential produced by a receptor cell in response to a sensory stimulus

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

What do we need to know about sensory stimuli? (four factors)

A

Modality: what?
Frequency: when?
Intensity: how much?
Location: where?

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

Modality (what)

A

Indicated by which neurons are active; different neurons have different pathways to the brain and different senses have specialized receptors

Receptive field: the area/type/range of stimulus that neurons/receptors process; various in size and complexity of stimulus and quality of receptor

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

Frequency (when)

A

When the stimulus occurs; the temporal distance between stimuli

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

Intensity (how much)

A

Graded changes in potential and action potential firing rate

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

Location (where)

A

From where the stimulus comes into the body

In the eye, visual info hits different parts of the retina which correspond to nerve and reception location

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

Dynamic range

A

Neurons have a low ratio of largest signal to smallest signal; made up for by relative timing of action potentials and pattern of firings over time (range fractionation, adaptation, lateral inhibition)

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

Range fractionation

A

Different receptors and pathways carry info from different ranges of stimuli

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

Adaptation

A

Rapidly and slowly adapting neurons; neurons don’t conduct steady info, so rate of firing decreases after initial burst –> change or differential is more informative than absolute value

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

Lateral inhibition

A

Sharpens edges and contrast rather than absolute levels; interneurons at relays between afferent neurons send inhibitory signals to moderate signals while emphasizing intense signals

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

Sensory pathway for eyes

A

eyes –> thalamus –> primary visual cortex

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

Sensory pathway for ears

A

ears –> midbrain –> thalamus –> temporal lobe

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

Sensory pathway for skin

A

skin –> midbrain –> thalamus –> primary sensory cortex

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

Sensory pathway for smell

A

nose –> temporal lobe

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

Stimulus in the visual system

A

light (electromagnetic radiation)

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

Acuity

A

Depends on convergence of photoreceptors onto ganglion cells

Less acuity = more photoreceptors per ganglion cell
Highest acuity = one photoreceptor per ganglion cell (fovea)

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

How does light travel through the eye?

A

cornea –> pupil –> lens –> retina

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

Fovea

A

The center of the retina where most cones are concentrated; has the highest visual acuity

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

How does light travel through post-retinal neurons?

A

photoreceptors (rods and cones) –> horizontal cells –> bipolar cells –> ganglion cells

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

Rods

A
  • long outer segment
  • more discs and photopigments
  • one type of pigment opsin
  • do not contribute to color vision
  • greater light sensitivity
  • low-light
  • periphery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Cones

A
  • short outer segment
  • fewer discs and photopigments
  • three types of pigment opsins (blue, green, red)
  • ability to perceive color
  • daylight
  • center/fovea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

How do photoreceptors contribute to the flow of info?

A

Photoreceptors transduce light into a graded potential which alters glutamate release (hyperpolarizing)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How do bipolar and ganglion cells contribute to the flow of info?

A

On-center or off-center cells react differently based on location and type of stimulus (depolarizing)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

How do horizontal and amacrine cells contribute to the flow of info?

A

Mediate horizontal interactions of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

How do ganglion cells contribute to the flow of info?

A

Fire action potentials and send axons to the higher visual system (excitatory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Explain center-surround receptive fields

A

Sensory systems are interested in contrast rather than absolute levels; on-center and off-center cells are either excitatory or inhibitory depending on where in their field the light is shone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

On-center cell response

A

Light shone onto center: excitatory
Light shone onto surround: inhibitory
Light diffused across both: weak response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Off-center cell response

A

Light shone onto center: inhibitory
Light shone onto surround: excitatory
Light diffused across both: weak response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

How do cones and ganglion cells respond to colored light?

A

Cones come in red, green, and blue
Ganglion cells come in red-green or yellow-blue

Different colors of light excite or inhibit different cones and ganglion cells to determine color perception

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Types of ganglion cells

A

Magno and parvo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Magno cells

A

Large, lots of myelin, rapid conduction, provide info about motion and location

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Parvo cells

A

Small, less myelin, slower conduction, provide info about form and color

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Lateral Geniculate Nucleus (LGN)

A

Structure in the thalamus where visual information travels to; retinotopic organization maintained from LGN to primary visual cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Six layers of the LGN

A

Layer 1: contralateral eye, magno cells
Layer 2: ipsilateral eye, mango cells
Layers 3 and 5: ipsilateral eye, parvo cells
Layers 4 and 6: contralateral eye, parvo cells

73
Q

Structure of primary visual cortex (striate cortex)

A

Six striated layers organized into ~2,500 modules

74
Q

Modules

A

Each module receives input from both eyes, all orientation columns, and blobs for one region of the visual field

Process info from a specific area and pass it on to other modules

Can be synonymous with a hypercolumn or made up of multiple hypercolumns

75
Q

Hypercolumns

A

Receive info from both eyes and all orientations; contain ocular dominance columns, orientation columns, and blobs

76
Q

Ocular dominance columns and orientation columns

A

Ocular dominance columns: columns perpendicular to cortical surface of primary visual cortex (aka striate cortex) and are either left or right eye dominant

Orientation columns: respond to specific orientations of visual info; cross-reference with ocular dominance columns

77
Q

Cells in the V1

A

Interested in oriented edges rather than circular receptive fields

Simple cells, complex cells, and hypercomplex cells

78
Q

Simple cells

A

Center-surround inhibition with a line of certain orientation; cell only responds to stimuli that fall within the excitatory region

79
Q

Complex cells

A

Line of certain orientation moving in receptive field; cell is excited by any stimulus of that orientation, but in any location

80
Q

Hypercomplex cells

A

Line of certain orientation with end inhibitory regions, detect ends of lines of particular orientation; excited by stimuli whose ends don’t intercept with inhibitory region

81
Q

Two main visual processing streams out of V1

A

Dorsal stream (where and how) and ventral stream (what)

82
Q

Dorsal stream

A

Where and how: analysis of motion, spatial relations, shape, and size

Direct movements such as eye movement, reaching, grasping, other guided movements

Associated with magno neurons

Goes to posterior parietal lobe via intraparietal sulcus

83
Q

What might occur with damage to the dorsal stream?

A

Akinetopsia or visuospatial neglect

84
Q

Akinetopsia

A

Extremely rare disorder where patients cannot perceive motion; occurs with bilateral damage to V5 and results in processing of snapshots without any flow

85
Q

Visuospatial neglect

A

More common disorder where the brain neglects to consciously process certain areas of the visual field (most commonly left visual field with damage to right parietal damage)

Patients can sense stimuli on the neglected side, but ignore it until it’s been pointed out to them

86
Q

Ventral stream

A

What: form and color

Includes lateral occipital complex (LOC), fusiform face area (FFA), extrastriate body area (EBA), and parahippocampal place area (PPA)

Associated with parvo neurons

Goes to temporal lobe via V2, V4, and ITC

87
Q

Lateral occipital complex (LOC)

A

Responsive to objects

88
Q

Fusiform face area (FFA)

A

Responsive to faces and other areas of human expertise; in the inferior temporal cortex

89
Q

Extrastriate body area (EBA)

A

Responsive to human bodies and body parts

90
Q

Parahippocampal place area

A

Responsive to scenes and backgrounds

91
Q

Cerebral achromatopsia

A

Damage to V4 causes non-retinal color blindness; patient only sees in black and white and cannot imagine or remember color

92
Q

Visual agnosias

A

A set of disorders caused by damage to the ventral stream and characterized by failure to know/inability to perceive or identify visual stimulus

Prosopagnosia and object agnosia

93
Q

Prosopagnosia

A

Damage to FFA

Congenital prosopagnosia or Williams Syndrome

Patient can identify details in an image, but is unable to piece together the details into the context of a larger, whole image (including faces)

94
Q

Object agnosia

A

Patient can identify the larger object but not its details

95
Q

Transduction in the auditory system

A

outer ear –> middle ear –> inner ear and Organ of Corti

96
Q

Transmission in the auditory system

A

spiral ganglia –> brainstem cochlear nuclei –> medulla (superior olivary complex) –> decussation –> inferior colliculi –> MGN of the thalamus –> primary auditory cortex (A1)

97
Q

Auditory stimulus

A

Compressions and rarefactions of air

Frequency, amplitude, and timbre

98
Q

Frequency

A

Hz, perception of pitch

Human auditory range is 20 Hz to 20,000 Hz

99
Q

Amplitude

A

dB, perception of loudness

100
Q

Timbre

A

Complexity of sound

101
Q

Outer ear

A

Pinna, ear canal, tympanic membrane (separation)

102
Q

Middle ear

A

Ossicles and oval window

103
Q

Inner ear

A

Cochlea

104
Q

Impedance matching

A

The ear turns movement in air into movement in fluid; air vibrations tend to lessen in fluid

Waves are amplified to match original impact by the oval window being much smaller than the tympanic membrane

105
Q

Conductive hearing loss

A

Problem in outer or inner ear such as earwax, swimmer’s ear, ruptured eardrum, otitis media, or ostosclerosis

106
Q

Sensorineural hearing loss

A

Problem in cochlea; presbycusis or noise-induced

107
Q

Cochlea

A

Aka snail shell or bony labyrinth

Oval window vibrated by ossicles; fluid in cochlea vibrates up to apex and back down to displace round window

108
Q

Chambers of the cochlea

A

Oval window inserts into the scala vestibuli, which winds up to the apex and comes back down as the scala tympani

The scala media sits between the other two chambers

109
Q

Scala vestibuli and scala tympani

A

Filled with perilymph (extracellular fluid) which vibrates with vibrations of the oval window

110
Q

Scala media

A

Filled with endolymph (high in potassium and low in sodium); contains the basilar membrane and the Organ of Corti

111
Q

Organ of Corti

A

This is where fluid vibration turns into electrical signals sent to the brain; done via hair cells with potassium channels

112
Q

Hair cells

A

Inner: carry 90% of auditory signal
Outer: modulatory/amplifying role

Hair cells release more (depolarization) or less (hyperpolarization) glutamate depending on whether they bend toward or away from the kinocilium, respectively

Tip links open and close potassium channels to alter neurotransmitter release into the auditory nerve

113
Q

How does the auditory system code for frequency?

A

Tonotopic mapping:

The Organ of Corti sits atop the basilar membrane

The basilar membrane is wider/floppier at the apex of the cochlea (lower freq.), and more narrow/rigid at the base (higher freq.)

Depending on frequency of sound, different places along the basilar membrane vibrate, causing different hair cells to activate

114
Q

Presbycusis

A

Progressive hearing loss of higher frequencies that increases with age; occurs with loss of outer hair cells starting at base to the apex of the basilar membrane, in addition to thickening of narrow base

115
Q

Noise-induced sensorineural deafness

A

One-time, very loud noise may cause hearing loss with possible recovery

Long-term exposure to moderately loud noise may lead to progressive loss

116
Q

Cochlear implant external mechanisms

A

External: the microphone picks up on sound, the speech processor divides sound into channels, and the transmitter transmits to the receiver

117
Q

Cochlear implant internal mechanisms

A

Internal: receiver and stimulator convert signals into electric impulses sent via cable to electrodes, an array of ~120 electrodes is wound through the cochlea to stimulate the spiral ganglion

117
Q

How does the auditory system code for amplitude?

A

The firing rate of the spiral ganglion and the auditory nerve

The spread of firing of axons; more intense sound will maximally shift larger area of the basilar membrane, indicating that the sound is louder

118
Q

How does the auditory system code for location?

A

Distance: intensity attenuates with distance, high frequencies attenuate more than low

Direction: vertical (bad in humans) and horizontal (good in humans) planes

Input from both ears is integrated at the superior olive in the medulla where timing differences help map out locations in space

119
Q

Horizontal hearing cues

A

Interaural intensity cues and interaural timing cues

120
Q

Interaural intensity cues

A

Head forms “sound shadow” so sound is louder in the ear that it’s closest to; this is mostly used for higher frequencies

121
Q

Interaural timing cues

A

Relative phase will reach each ear at a different point depending on its location; this is mostly used for lower frequencies

122
Q

How do we perceive complex sounds?

A

Pattern recognition, localization, planum temporale, and further processing streams

123
Q

Pattern recognition

A

Extraction of particular patterns of constantly changing activity

124
Q

Planum temporale

A

Area with many connections between auditory system and cortical language areas, including primary and secondary auditory cortices and Wernicke’s area

125
Q

Auditory processing streams for language

A

Dorsal: sound to motor output of speech (e.g. “repeat after me”); Broca’s area

Ventral: sound to meaning; Wernicke’s area

126
Q

How is music processing differently in the brain?

A

Processing in auditory association cortices is more complex and right-lateralized

127
Q

How does the brain change with musical training?

A

Motor system: violinists, pianists, etc. have higher cortical representation of non-dominant hand

Auditory system: A1 is 130% larger and 102% more responsive

Connectivity: corpus callosum and arcuate fasciculus volume/response differ between different types of musical training

128
Q

Amusia

A

A disorder where patients have a normal perception of speech and environmental sounds, but reduced ability to process music; music sounds like meaningless noise without tune or melody

Usually acquired and congenital and features a thicker right STG and right IFG

129
Q

What does the vestibular system do?

A

Maintains balance, keeps the head in an upright position, and adjusts eye movements to accommodate for head movements

130
Q

Structures of the vestibular system

A

Vestibular sacs and semicircular canals

131
Q

Vestibular sacs

A

Utricle and saccule; respond to gravity and info about head orientation

Floor of utricle and wall of saccule contain patches of receptive tissue with hair cells embedded into gelatinous mass containing otoconia (small crystals of calcium carbonate)

The weight of the otoconia causes mass to shift as orientation of head changes, shearing cilia of hair cells

132
Q

Semicircular canals

A

Respond to angular acceleration and changes in head rotation alone three major planes of the head

Receptors in each canal respond to angular acceleration in one plane

Cupula within ampulla exerts shear on hair cells

133
Q

Cutaneous senses

A

Having to do with the skin

134
Q

Proprioception

A

Having to do with body position

135
Q

Kinesthesia

A

Having to do with movement

136
Q

Two-point discrimination

A

Reflects the degree of somatosensory innervation of the skin at different locations

2-4 mm on the fingertip; 4-5 cm on the thigh

137
Q

How does touch code for location?

A

The organization of dermatomes and which receptors are active

138
Q

How does touch code for intensity?

A

Receptor activity reflects degree of skin indentation

139
Q

Four important mechanoreceptors

A

Merkel disks, Meissner corpuscles, Pacinian corpuscles, and Ruffinin endings

140
Q

Properties of Merkel disks

A

Code for pressure, have a smaller receptive field, shallow, slowly adapting 1 fiber, low frequency range of 0.3-3 Hz

141
Q

Properties of Meissner corpuscles

A

Code for fluttering touch, have a smaller receptive field, shallow, rapidly adapting 1 fiber, frequency range of 3-40 Hz

142
Q

Properties of Ruffini endings

A

Code for stretching, larger receptive field, deeper, slowly adapting 2 fiber, frequency range of 14-400 Hz

143
Q

Properties of Pacinian corpuscles

A

Code for vibration, larger receptive field, deeper, rapidly adapting 2 fiber, frequency range of 10-500 Hz

144
Q

Temperature receptors

A

Different receptors exist for different temperature ranges; 6 main thermal receptors from the TRP family

Cold temp. receptors are more superficial while warm temp. receptors are deeper

145
Q

Proprioceptors

A

Receptors that receive info from muscles and joints; muscle spindles and golgi tendon organs

146
Q

Muscle spindles

A

Lay parallel to muscles and are very sensitive to the length and stretch of muscles; provide sensory input for stretch reflect where brain is not required

LA afferent circuits

147
Q

LA afferent circuit

A

Muscle spindle sends info to spinal cord via LA afferent neurons –> synapse directly onto alpha moto neurons –> inhibitory neurons innervate reciprocal muscles –> agonist is active, and the antagonist relaxes

148
Q

Golgi tendon organs

A

Junctions between tendons and muscles; good at sensing load and weight and protects muscles from excessively heavy loads by causing muscle to relax and drop

149
Q

How does touch info get to the brain?

A

Sensory signals join spinal cord at different points depending on location and dermatomes –> info goes into dorsal root ganglion and out from ventral root –> medial lemniscal pathway

150
Q

Medial lemniscal pathway

A

Dorsal pathway where touch info travels through dorsal column, decussates in the medulla, and travels to the thalamus and the somatosensory cortex

151
Q

Where does touch info go in the thalamus?

A

Thalamic projections to different subzones:

Spindles project to 3b
SA and RA mechanoreceptors project to 3b
RA mechanoreceptors project to 1
Deep tissue (pressure and limb position) project to 2

152
Q

In what order does info pass through the somatosensory cortex?

A

Area 3 –> areas 1, 2, and 5

Receptive fields become larger and more complex and contain input from multiple receptor types and sources

153
Q

Pain

A

Not excessive sensory stimulation, but actually a completely different input carried to the brain through different pathways

154
Q

Pain receptors

A

Nociceptors

155
Q

Components of pain

A

Sensory: pure perception
Emotional: immediate and chronic

156
Q

What pathway does pain follow?

A

Tissue damage –> peripheral nerves –> spinal cord –> thalamus –> somatosensory cortex, frontal cortex, limbic system

157
Q

Anterolateral or spinothalamic system

A

Pain fibers carry info into dorsal horn and decussate immediately, allowing for immediate reflex processing in the spinal cord

Signal travels up to the brain in anterolateral/spinothalamic tract and distributes to various regions

158
Q

Brain regions involved in pain processing

A

Limbic system (emotional component), anterior cingulate cortex, midbrain periaqueductal gray (PAG), red nucleus, medullary raphe nuclei, reticular formation

159
Q

Brain mechanisms for emotional component

A

Immediate: ACC and insula
Chronic: prefrontal cortex

160
Q

Insula

A

Codes for emotional response to pain and processing of harm associated with certain actions; linked to motor system

161
Q

What would damage to the insula cause?

A

Decrease in emotional response; patients would feel the pain but not perceive it as harmful or something to be avoided

162
Q

Anterior cingulate cortex (ACC)

A

Codes for emotional unpleasantness of pain; activated when receiving pain or seeing other receiving pain, indicating connection to pain perception

Activity can decrease through hypnosis meant to reduce perception of unpleasantness of pain

Linked to limbic system

163
Q

What is the effect of endogenous opioids?

A

Pain perception is modified by hormones or NTs released based on environment or context

Descending pathway from brain to spinal cord acts to “intercept” and inhibit pain signals at every level of cord, stopping conscious perception in the brain

164
Q

Gate Theory

A

States that the transmission of pain signals can be modulated by descending pathways and interactions between touch and pain fibers in cord; signals are gated from getting to the brain

165
Q

Methods of pain treatment

A
  • stimulation of PAG (analgesia)
  • opiates
  • anti-inflammatories
  • placebo effect
166
Q

How does phantom limb pain appear?

A

Input from residual limb such as muscle contractions, ectopic activity from neuroma, dorsal root ganglia, and spinal cord; reorganization or preserved function in central nervous system

Contextual factors such as sensory stimulus, motor signals, and psychological factors

167
Q

Taste

A

Gustation (bitter, sour, sweet, salty, umami)

168
Q

How does the tongue process taste?

A

Tongue, palate, pharynx, and larynx contain about 10k taste buds mostly around foliate papillae on back of tongue

169
Q

How do taste buds work?

A

Each contain about 20-50 receptor cells with protruding cilia

Transduction: chemical binds to receptor, alters membrane permeability, receptor potential, and NT release (mostly via G-protein)

170
Q

How does taste info reach the brain?

A

Ipsilateral

Tongue –> chorda tympani –> nucleus of solitary tract (NST) in medulla –> thalamus –> gustatory cortex in insula

171
Q

Where in the brain is taste info processed?

A

Primary gustatory cortex (insula) and secondary gustatory cortex (orbitofrontal cortex)

Hypothalamus and amygdala/limbic system

172
Q

Smell stimulus

A

Oderants and volatile substances

173
Q

Smell receptor cells

A

Six million olfactory receptors (bipolar neurons) in the olfactory epithelium at the top of the nasal cavity

174
Q

How do olfactory receptors work?

A

Receptor cilia are sent to the surface of the mucosa where they are split into 10-20 cilia that penetrate mucus layer

Mucus dissolves oderants and stimulate receptors, then bundles of axons enter skull via holes in the cribriform plate and project towards the olfactory bulb

175
Q

Olfactory bulb

A

Each receptor sends a single axon to the bulb where the axons synapse onto mitral cells in olfactory glomeruli

176
Q

Mitral cells

A

Axons travel to rest of brain via olfactory nerve

177
Q

Olfactory glomeruli

A

Bundle of dendrites of mitral cells and terminal buttons of axons

178
Q

Where in the brain is smell processed?

A

Primary olfactory cortex in the limbic region, contain piriform and entorhinal cortices with olfactopic map

Piriform cortex sends signals to hypothalamus or dorsomedial thalamus and orbitofrontal cortex

NEUR-210 (3 decks)

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