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KIN 255 > Quiz 1 > Flashcards

Quiz 1 Flashcards

1
Q

What two cell types is the nervous system made of?

(and what percent of each?)

A

Neurons and glial cells

50% neurons and 50% glial cells

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2
Q

What are the 3 types of glial cells?

A
  1. Oligodendrocytes (in CNS, Schwann cell in PNS)
  2. Astrocytes
  3. Microglia
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3
Q

What is the purpose of oligodendrocytes?

A
  • Provides physical support/structure
  • Insulate neurons (myelinate/produce myelin)
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4
Q

What is the purpose of astrocytes?

A

-Supply nutrients and oxygen
-Bridge b/w nervous and vascular system

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5
Q

What is the purpose of microglia?

A

Clean up debris

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6
Q

Which glial cell is only found in the PNS and what is its equivalent in the CNS?

A

Schwann cell (equivalent of oligodendrocytes)

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7
Q

What is post-synaptic potential (PSP)?

A

A graded electrochemical response
(the PSPs from many dendrites converge at axon hillock)

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8
Q

What is the convergence of post-synaptic potential (PSP)?

A

Integration

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9
Q

What is Action Potential (AP)?

A

All or nothing electrochemical response

(resting @ -70mV and threshold @ -55mV)

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10
Q

What is Spatial summation?

A

Multiple EPSPs (Excitatory post synaptic potential) happening close together.

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11
Q

What are the (10) parts of a neuron?

A

-Dendrites
-Cell body
-Cell membrane
-Node of Ranvier
-Schwann Cell
-Nucleus
-Axon
-Axon hillock
-Myelin Sheath
-Axon terminal

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12
Q

What part of a neuron receives signals from other cells?

A

Dendtrites

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13
Q

What part of the neuron is responsible for organization and keeping the cell functional

A

Cell body

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14
Q

What part of the neuron protects the cell?

A

Cell membrane

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15
Q

What are the Nodes of Ranvier?

A

-Unmyelinated parts of axon
-Allow diffusion of ions

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16
Q

What produces the myelin sheath? (in PNS)

A

Schwann cell

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17
Q

What controls the entire neuron?

A

Nucleus

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18
Q

What transfers signals to other cells/organs?

A

The axons

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19
Q

What generates an impulse in neuron?

A

Axon hillock

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20
Q

What increases speed of signal?

A

Myelin Sheath

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21
Q

What forms junctions with other cells?

A

Axon terminal

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22
Q

What is grey matter?

A

-Groups of cell bodies, dendrites and terminal endings.
-the site of integration and transformation

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23
Q

What cell bodies are in the grey matter of the CNS?

A

Nuclei

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24
Q

What cell bodies are in the grey matter of the PNS?

A

Ganglia

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25
Q

What is white matter?

A

-Bundles of myelinated axons
-Pathways or fiber tracts connecting areas of grey matter
(electric signals can skip past myelin, making them faster)

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26
Q

What is the central nervous system? (what makes it up)

A

Spinal cord, brain stem, cortex (within skeletal casing - skull/spinal column)

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27
Q

What is the peripheral nervous system?

A

Outside the skeletal casing. Further subdivided into the somatic (skeletal muscles) & autonomic (smooth muscles and glands)

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28
Q

Parts of the CNS: Spinal cord.

A

-Contains finer tracts:
-afferent or ascending (to the brain)
-efferent or descending (from the brain)
-Entry/exit zones of PNS
-Pods of interneurons that interact with ascending/descending pathways

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29
Q

What is a ganglion

A

Cluster of cell bodies in the PNS

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30
Q

What is nuclei

A

Cluster of cell bodies in the CNS

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31
Q

Parts of the CNS: Brain Stem

A
  • Pons, medulla (hindbrain) & midbrain
  • Contains the 12 cranial nuclei & sensory/motor nerves that innervate eyes, head, neck and upper trunk
    (nuclei in brainstem are critical to autonomic function, alertness and eye/hand movement)
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32
Q

Parts of the CNS: Cerebellum

A

‘little brain’
* contains >50% of brain neurons
* Has dense afferent and efferent connections with brainstem and cortex
* Influences cortex activity and ascending/descending projections

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33
Q

Parts of the CNS: Basal Ganglia

A
  • Group of subcortical nuclei that are adjacent to the thalamus and descending motor tracts
  • Important contribution to control of movement, learning, cognition and emotions
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34
Q

What structures are included in the Basal Ganglia

A
  • Caudate Nucleus
  • Putamen
  • Globus Pallidus (internal and external)
  • Substantia nigra
  • Subthalamic Nucleus (STN)
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35
Q

Parts of the CNS: Thalamus

A
  • Critical relay between cortex and other parts of CNS
  • Essential to sensorimotor processing (also plays role in alertness)
  • All sensory input from body (except smell) pass through thalamic nucleus
  • Olfactory system bypasses thalamus
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36
Q

Parts of the CNS: Hypothalamus

A
  • Contributes to control of many internal body functions & regulation of homeostasis
  • Links between nervous system and endocrine system
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37
Q

Name the lobes of the cerebral cortext

and where they are

A

Frontal lobe (front of head)
Parietal Lobe (behind frontal)
Occipital lobe (back of head)
Temporal lobe (by ears, under frontal/parietal)

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38
Q

What is sulci

A

Deep valleys of the folds of the cortex

Main sulci include central sulcus (between frontral and parietal lobe) and parieto-occipital sulcus (between parietal and occipital lobe)

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39
Q

Describe Frontal Lobe

A
  • Action control (body/eye movement, speech)
  • Control of high-level cognitive/executive function (planning)
  • Behaviour and emotion control (including personality)
  • Controls voluntary behaviour
  • Most developed (in humans)
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40
Q

Describe Parietal Lobe

A
  • Receives and processes touch and taste sensory info
  • Receives processed visual and auditory information
  • Integrates info from senses for object perception, spatial awareness and motor control
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41
Q

Describe Occipital Lobe

A
  • Recieves raw visual input from the visual thalamus
  • Early processing of colour, edges, motion of objects and self-movement through the environment
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42
Q

Describe the Temporal lobe

A
  • Recieves raw auditory input from thalamus
  • Early processing of sound (intensity, pitch, location)
  • Storage and retrieval of memories
  • Combines visual info into object perception
  • Classification and grouping of objects
  • Emotion processing

Amygdala and hippocampus are sometimes lumped in with temporal lobe

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43
Q

Cerebral cortex taxonomy

What is Brodmann area

A
  • Regions of cortex grouped by cytoarchitechture
  • cytoarchitecture mirrors function, creating a link between the Brodmann area and functional cortex taxonomy
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44
Q

what is cytoarchitecture

A

Density of cells contained in grey matter of cortex

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45
Q

Cerebral cortex taxonomy

Explain the Primary cortex regions

A

1st arrival of sensory input or last stop for motor output (primary regions are very specific)

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46
Q

Cerebral cortex taxonomy

What are the primary regions for each lobe

A
  • Primary motor cortex (frontal)
  • Primary somatosensory cortex (parietal)
  • Primary visual cortex (occipital)
  • Primary auditory cortex (temporal)
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47
Q

cerebral cortex taxonomy

Explain secondary cortical regions

A

Recieves processed info and puts it into the big picture (right next to primary region)

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48
Q

cerebral cortex taxonomy

Explain Association areas of cortex

A

Another name for ‘secondary’ that reflects integration of info. Integrates info among regions/cortexs/lobes

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49
Q

What are sensory receptors and what do they do

A

Specialized cells or endings that convert stimulus energy to electrical potential that can be transmitted and interpreted by nervous system

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50
Q

Sensory receptors

What are the 4 main types of Sensory receptors

A
  1. Mechanoreceptors
  2. Photoreceptors
  3. Chemoreceptors
  4. Thermoreceptors
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51
Q

Sensory receptors

What is common to all Sensory receptors

A
  • They are a mechanism by which the stimulus energy leads to a change in electrochemical state of cell or axon (receptor potential)
  • A mechanism to convert “passive” receptor potential into action potential
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52
Q

Sensory receptors

What do mechanoreceptors do

A

convert mechanical enery (force)

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53
Q

Sensory receptors

What to photoreceptors do

A

Convert light energy (photons)

in retina

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54
Q

Sensory receptors

What do chemoreceptors do

A

Convert chemical energy

tastebuds; pain receptors

55
Q

Sensory receptors

What do thermoreceptors do

A

Convert thermal energy

in skin

56
Q

Sensory receptors

Explain receptor potential

A

generated by the passive diffusion of ions in/out of cell (specific to sensory receptor)

57
Q

Sensory receptors

Explain Action potential

A

Generated by influx/efflux of ions. Constantly regenerated as it travels along axon

58
Q

Sensory receptors

How can a receptor represent certain types of stimulus info?

4 ways

A
  1. Type or modality
  2. Onset, offset, duration
  3. Intensity
  4. Location

of stimulus

59
Q

Sensory receptors

Type or modality of stimulus

how many stimulus types is each receptor tuned to

A

Each Sensory receptor is tuned into a specific type of stimulus

1 receptor : 1 stimulus type

60
Q

Sensory receptors

Onset, offset, duration of stimulus

Stimulus timing (what happens to the activity)

A

the activity of the sensory receptor changes depending on the presence or absence of the stimulus

61
Q

Sensory receptors

Intensity of stimulus

howdo sensoy receptors convey intensity

A

Sensory receptors scale their influence over nerves by adjusting how many AP are triggered per unit time

62
Q

Sensory receptors

Location of stimulus

How do receptors convey location infomation

A

Sensory receptors project to the spinal cord, brain stem and cortex via labelled lines

63
Q

Sensory receptors

What are the (8) different types of stimulus modality

A
  • Touch/ tactioception
  • movement/proprioception
  • orientation/equilibrioception
  • hearing/ audioception
  • sight/opthalamoception
  • smell/olfacoception
  • taste/gusaoception
  • paint/nociception
64
Q

Sensory receptors: modality

what does tactioception sense

A

change to external/internal state of body

touch

mechanoreceptors

65
Q

Sensory receptors: modality

what does proprioception sense

A

position/movement of body; force/effort of movement

movement

mechanoreceptors

66
Q

Sensory receptors: modality

what does equilibrioception sense

A

body position/movement in relation to gravity

orientation

mechanoreceptors

67
Q

Sensory receptors: modality

what does audioception sense

A

surrounding environment from sound waves

hearing

mechanoreceptors

68
Q

Sensory receptors: modality

what does opthalamoception sense

A

objects/environment from visual light

sight

photoreceptor

69
Q

Sensory receptors: modality

what does olfactoception sense

A

chemical odorants in nasal cavity

smell

chemoreceptor

70
Q

Sensory receptors: modality

what does gustaoception sense

A

substances that chemically react in the mouth

taste

chemoreceptor

71
Q

Sensory receptors: modality

what does nociception sense

A

pain related to injury/damage

pain

mechano & chemo receptors

72
Q

Sensory Sytems

What are the main Sensory Sytems

A
  1. Somatosensory
  2. vestibular
  3. visual
  4. auditory
73
Q

Sensory Sytems

What is the somatosensory system made of

A

Any mechano, thermo or nociceptor in skin, fatty tissue beneath skin, muscles or musculoskeletal tissue (ligament, tedon, joint capsule)

74
Q

Sensory Sytems

What is the vestibular system made of

A

mechanoreceptors within otoliths/labrinths of inner ear

75
Q

Sensory Sytems

What is the visual system made of

A

photoreceptors in retina

76
Q

Sensory Systems

What is the auditory system made of (what receptors where)

A

mechanoreceptors in cochlea within inner ear

77
Q

Sensory Sytems and receptors

how do sensory receptors convey information about timing

A

they modulate dynamic properties of the receptor potential. 2 types:
1. Fast adapting
2. Slow adapting

78
Q

Sensory Sytems and receptors

Explain fast adapting

A
  • Vigorous but transient response to changes in stimulus energy
  • info about onset/offset but not a lot about signal itself
  • optimal to detect rate of change in stimulus energy intensity
79
Q

Sensory Sytems and receptors

Explain slow adapting

A
  • measured, but sustained, response while stimulus energy is constant
  • info about duration/ intensity of signal
  • reflects actual stimulus energy intensity
80
Q

Sensory Systems and receptors

Stimulus location: Labelled Lines

A
  • axons innervate receptors of one modality, from a specific body area
  • axons bundle together, but their signals remain separate until reaching ‘higher’ areas of NS

Afferent fibers contain specific modality and location information and this is referred to as labelled line coding

81
Q

Sensory Sytems and receptors

What is somatotopic

A

Perserved info about body location

82
Q

Sensory Sytems and receptors

What is tonotopic

A

perserved info about sound frequency

83
Q

Sensory Sytems and receptors

what is retinotopic

A

perserved into about spatial location in visual field

84
Q

How does afferent info enter CNS

A

Dorsal root

85
Q

How does efferent info exit CNS

A

Ventral root

86
Q

Photoreceptors

How do photoreceptors generate receptor potential

A

Photoreceptors absorb photons from visual light wavelengths leading to a chemical reaction that generates the receptor potential

87
Q

Photoreceptors

Describe the Photoreceptors process in light

A
  1. Pigment (eg Rhodopsin) absorbs light
  2. Initiates a 2nd messenger pathway that closes NA+ ion channels
  3. Less Na+ influx decreases the amplitude of the receptor potential
  4. Less neurotransmitter (glutamate) is released when the RP reaches the end of the receptor

Opposite in dark (more neuroreceptor is released)

88
Q

Photoreceptors

How are Photoreceptors unique from other sensory receptors

A

They do not directly influence the sensory nerve (ganglion cell).
They instead act via an intermediary cell called bipolar cell

89
Q

Photoreceptors

When the RP is smaller, is the bipolar cells influence on the ganglion cell stronger or weaker?

A

Stronger

smaller RP = stronger stimulus energy

90
Q

Photoreceptors

What are the two types of Photoreceptors

A

Rods and Cones

91
Q

Photoreceptors

Rods

A
  • along boundary of retina
  • contain the pigment rhodopsin
  • all rods have same time of rhodopsin (tuned to detect cyan/green spectrum)
  • ~96% of all Photoreceptors
92
Q

Photoreceptors

Cones

A
  • Clustered in centre of retina
  • contain pigment iodopsin
  • each cone has different form of iodopsin that is sensitive to a specific wavelength
  • 3 types (blue, red, green)
  • ~4% of photoreceptors
93
Q

Hair cells

What are hair cells (and what senses/systems are they used for)

A

mechanoreceptors that mediate our auditory and vestibular senses

94
Q

Mechanoreceptors: Hair cells

Kinocilium

A

larger hair cell

95
Q

Mechanoreceptors: Hair cells

Stereocilia

A

shorter bunch of hair cells

96
Q

Mechanoreceptors: Hair cells

What happens if hair cells deflect towards kinocilium

A

depolarization or cell leading to increased firing rate

97
Q

Mechanoreceptors: Hair cells

What happens if hair cells deflect away kinocilium

A

hyperpolarization or cell leading to decreased firing rate

98
Q

Hair cells: Auditory

Describe auditory process

A
  1. soundwaves apply pressure to tympanic membrane
  2. movement of tympanic membrane creates vibration of small bones in ear
  3. bone vibration creates waves in fluid of cochlea (inner ear)
  4. fluid movement causes basilar membrane to vibrate, causing hair cell base to move back and forth
  5. Techtoral membrane, connected to hair filament, is rigid and does not move
  6. Differential movement of basilar tectorial membranes create a shearing force that opens Ca2+ or K+ ion channels. This leads to excitatory release of neurotransmitter from receptor cell
99
Q

Hair cells: Auditory

What is the tonotopic map and how is it generated?

A

Location of specific axons generating AP represents specific frequency of sound. it is generated by differential compositions of the basilar membrane as it winds around the cochlea. Lower frequency must travel further into cochlea before activation/interaction

100
Q

Vestibular (anglular rotation)

How do we sense angular rotation

A

Hair cells embedded in the semicircular canals mediate our sense of angular head rotation

101
Q

Hair cells: Vestibular (anglular rotation)

What are the 3 semicircular canals

A
  1. horizontal
  2. superior
  3. posterior
102
Q

Hair cells: Vestibular (anglular rotation)

What rotation does Horizontal canal sense

A

Side to side (Yaw)

103
Q

Hair cells: Vestibular (anglular rotation)

What rotation does the superior canal sense

A

Nodding (pitch)

104
Q

Hair cells: Vestibular (anglular rotation)

What rotation does the posterior canal sense

A

Head to sholder movement (roll)

105
Q

Hair cells: Vestibular (anglular rotation)

Describe left head rotation

A
  1. Head accelerates forward
  2. endolymph (viscous fluid) in canal experiences a moment of inertia
  3. Inertial moment creates shearing force on hair filament
  4. Left ear: pushes stereocilia towards kinocilium, opening K+ ion channels. Right ear: force pushes kinocilium towards stereocilia, closing ion channels
  5. K+ influx into left ear generates strong RP leading to release of exitatory neurotransmitter and increase in # of AP in left nerve. Right hair cell becomes hyperpolarized and releases less neurotransmitter leading to less APs
106
Q

Hair cells: Vestibular (head translation)

Explain head translation

(what mediates our perception of this)

A

Hair cells embedded in otolith organs mediate our perception of head translation and gravitational forces

107
Q

Hair cells: Vestibular (head translation)

What does the Utricle sense

A

Horizontal acceleration of head. (ex. car moving away from stop sign)

It is an otolith organ

108
Q

Hair cells: Vestibular (head translation)

What does the saccule sense

A

vertical acceleration (ex elevator)

it is an otolith organ

109
Q

Hair cells: Vestibular (head translation)

Explain forwards acceleration

A
  1. head accelerates forward, hair embedded in the bone moves with the head
  2. Otolith membrane of utricle, floating in endolymph, experiences moment of inertia
  3. Inertial moment created shearing force on hair filaments
  4. Force pushes stereocilia towards kinocilium, opening K+ channels
  5. K+ influx into hair cell generated strong RP, leading to release of excitatory neurotransmitter and increase in AP of both left and right nerves
110
Q

Mechanoreceptors: Cutaneos receptors

What do Cutaneos mechanorerceptors do

A

Translate mechanical forces acting on skin into RP through mechanically gated ion channels

111
Q

Mechanoreceptors: Cutaneos receptors

What are the 4 types of Cutaneos receptors

A
  1. Merkel Disks
  2. Ruffini Endings
  3. Pacinian corpuscle
  4. Meissner corpuscle
112
Q

Mechanoreceptors: Cutaneos receptors

Explain Merkel disks and Ruffini endings

A
  • Slow adapting
  • Na+ and CA2+ ion channels in receptor cells are mechanically deformed as skin is stretched
  • Mech deformation creates pore for ions to flow through
113
Q

Mechanoreceptors: Cutaneos receptors

Explain Messner and Pacinian corpuscles

A
  • Rapidly adapting
  • ion channels on an exposed nerve ending are mechanically deformed as corpuscles iscompressed
114
Q

Mechanoreceptors: Cutaneos receptors

Which mechanoreceptors are fast adapting

A
  1. Meissner corpuscles
  2. Pacinian corpuscle
115
Q

Mechanoreceptors: Cutaneos receptors

Which mechanoreceptor are slow adapting

A
  1. Merkel disk
  2. Ruffini ending
116
Q

Mechanoreceptors: Cutaneos receptors

Which mechanoreceptors are superficial

A
  1. Meissner corpucle
  2. Merkel disk
117
Q

Mechanoreceptors: Cutaneos receptors

Which mechanoreceptors are deep

A
  1. Pacinian corpuscle
  2. Ruffini ending
118
Q

Mechanoreceptors: Cutaneos receptors

Describe superficial receptors

A
  • have small receptive fields
  • are densly populated in areas of skin used to explore object

small and concentrated

119
Q

Mechanoreceptors: Cutaneos receptors

Describe deep receptors

A
  • Large receptive fields
  • best suited to detect vibrations in objects (ex water inside bottle) and skin stretch created bu object weight (bottle slipping from grasp)

large and blurry, not for details

120
Q

Mechanoreceptors: Proprioceptors

What to proprioceptors do/translate

A

translate mechanical forces generated by body’s own position/ movement

121
Q

Mechanoreceptors: Proprioceptors

3 types of proprioceptors

A
  1. Muscle spindle fibres
  2. Golgi tendon organs (GTO)
  3. Joint receptor
122
Q

Mechanoreceptors: Proprioceptors

What do muscle spindle fibres sense

A

Sense muscle length

123
Q

Mechanoreceptors: Proprioceptors

What do golgi tendon organs sense

A

Sense muscle force

in series with muscle

124
Q

Mechanoreceptors: Proprioceptors

What do joint receptors sense

A

Sense extreme joint angle

125
Q

Mechanoreceptors: Proprioceptors

What are the 2 classes of spindle fibres

A
  1. Dynamic (group 1a)
  2. Static (group II)
126
Q

Mechanoreceptors: Proprioceptors

Describe dynamic spindle fibres (+ what group)

A
  • Group Ia
  • activity is a function of both muscle length and rate of change in muscle length
  • more sensistive to rate of change
127
Q

Mechanoreceptors: Proprioceptors

Describe static spindle fibres

(what group?)

A
  • Group II
  • activity is a function of muscle length
  • get faster as spindle lengthens but not as dynamic
128
Q

Mechanoreceptors: Proprioceptors

Describe golgi tendon organs (GTOs)

A
  • Located in series between muscle fibre and tendon
  • forces generated by muscle and transmitted to bone must act on the GTO
  • Muscle contraction and relaxation
129
Q

Mechanoreceptors: Proprioceptors

Which causes more RP in spindle fibres, muscle contraction or relaxation

A

Muscle relaxation

130
Q

Mechanoreceptors: Proprioceptors

Explain muscle contraction

GTO

A
  • increased contractile force compressed GTO capsule
  • collagen fibres pinch interwoven axon endings which lead to mech deformation of axon membranes that open ion channels
  • influx generates RP
131
Q

Mechanoreceptors: Proprioceptors

Explain muscle relaxation

wrt GTO

A
  • decrease contractile force releases compression of GTO
  • Fibres released and resume ‘typical’ shape, leading ion channels to become less permeable, decreasing RP
132
Q

Mechanoreceptors: Nociceptive receptors

What do Nociceptive receptors do

A

Translate mech, chem and thermal forces from damaged tissue or the threat of damage to tissue

133
Q

Mechanoreceptors: Nociceptive receptors

What are bare nerve endings sensitive to

A
  • thermal (>45 or < 5 degrees)
  • mechanical (intense pressure on skin)
  • Chemical (internal or external toxins)
  • Polymodal (more than 1 stimulus type)
134
Q

Mechanoreceptors: Nociceptive receptors

Describe the difference between a blunt object, pinprick and pinch (with same amount of force) as an example of noxious touch

A

Blunt object:
* nociceptive axon demonstrate no response (no AP)
* Not noxious

Pinprick:
* Concentrated nature of force increases potential to penetrate skin
* percieved as noxious but minimal threat of harm

Pinch:
* Large area of high force
* high potential to break or severly damage skin/tissue
* Noxious with high threat of harm

KIN 255 (6 decks)

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