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Phase 1 flashcards > Neuro > Flashcards

Neuro Flashcards

1
Q

What is an action potential?

A

a sudden change in the voltage across a cell surface membrane due to the flow of certain ions in and out of the neuron

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2
Q

at the resting membrane potential, is the inside of the cell more or less negative?

A

more

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3
Q

What is the resting membrane potential?

A

the difference in electrical charge between the inside and the outside of the cell when it is at rest

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4
Q

What is the value for the RMP for neurons?

A

-70mV

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5
Q

Do all cells have the same RMP?

A

no

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6
Q

is K+ found at a higher concentration inside or outside the cell?

A

inside

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7
Q

are Na and Cl- found at higher concentrations inside or outside the cell?

A

outside

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8
Q

Which ion has the greatest impact on the RMP?

A

K+

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9
Q

How is the RMP maintained?

A

Na+ K+ ATPase
Actively pumps 3Na+ out, 2K+ in

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10
Q

Which ion is the membrane predominantly permeable to?

A

K+

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11
Q

Where does the action potential begin?

A

axon hillock (conical projection between the cell body and axon)

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12
Q

what happens during depolarisation?

A

voltage gated sodium ion channels open due to an electrical stimulus
fast influx of sodium ions to +30mV
their positive charge changes potential within the cell from negative to more positive

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13
Q

what is the threshold potential?

A

the value of membrane potential that must be reached by depolarisation for an action potential to be initiated

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14
Q

what is the value of the threshold potential?

A

-55mV

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15
Q

what does ‘all or nothing’ mean

A

if the threshold potential is reached, a response of the same magnitude is initiated regardless of the strength of the stimulus

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16
Q

what happens once the cell has been depolarised?

A

voltage gated sodium ion channels begin to close

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17
Q

why do voltage gated potassium channels open?

A

the potential within the cell is positive

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18
Q

what is repolarisation?

A

voltage gated potassium channels open
K+ ions leave the cell down their electrochemical gradient
the membrane potential becomes more negative and approaches the resting potential

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19
Q

what is hyperpolarisation?

A

repolarisation overshoots the resting potential
K+ channels are open slightly too long
the membrane potential becomes more negative

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20
Q

is Na+/ K+ ATPase involved in repolarisation?

A

no

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21
Q

what is a refractory period, and what are the two divisions?

A

time following an action potential
absolute refractory period
relative refractory period

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22
Q

when does the absolute refractory period occur

A

occurs when sodium channels close after an action potential
sodium channels cannot be opened regardless of the membrane potential

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23
Q

when does the relative refractory period occur?

A

sodium channels slowly come out of inactivation
action potentials can occur if the stimulus is large enough

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24
Q

what is saltatory conduction?

A

myelinated regions of the axon are not depolarised

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25
Q

why do action potentials only flow in one direction?

A

the refractory period

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26
Q

how are action potentials propagated along axons?

A

local currents flow following depolarisation and allow depolarisation of adjacent axonal membranes

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27
Q

what factors determine how far local currents travel?

A

capacitance and resistance

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28
Q

what is capacitance?

A

ability to store charge

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29
Q

how does capacitance affect the distance travelled by a local current?

A

a lower capacitance means a greater distance travelled

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30
Q

what is resistance?

A

number of ion channels open

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31
Q

how does myelin increase conducting speeds?

A

decreases capacitance and increases resistance

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32
Q

how does resistance affect the distance travelled by a local current?

A

a higher resistance means fewer ion channels open
means a greater distance travelled

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33
Q

what does osmium stain?

A

white matter/ myelin black

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34
Q

what stains myelin, and what colour?

A

osmium
black

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35
Q

what are the myelinating cells of the CNS?

A

oligodendrocytes

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36
Q

what are the myelinating cells of the PNS?

A

Schwann cells

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37
Q

what is MS?

A

immune system attacks the myelin sheath
saltatory conduction is disrupted
symptoms
- uncontrolled eye movement
- slurred speech

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38
Q

What is Guillain Barre Syndrome?

A

damage to PNS myelin
autoimmune
muscle weakness and pain

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39
Q

what is synaptic transmission?

A

process by which neurons communicate with each other

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40
Q

what are the types of synaptic transmission?

A

chemical (more common) and electrical

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41
Q

describe electrical synaptic transmission

A

gap junctions join pre and post synaptic clefts
very rapid adjacent depolarisation

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42
Q

give an example of where you can find an electrical synapse

A

brainstem e.g hypothalamic hormone secretion

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43
Q

describe a chemical synapse

A

5 stages
- manufacture
- storage in vesicles
- release
- activation at post synaptic receptors
- inactivation - breakdown or re-uptake

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44
Q

what is an EPSP?

A

a postsynaptic potential that propagates an action potential and results in depolarisation

excitatory post synaptic potential

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45
Q

what is an IPSP?

A

a postsynaptic potential that inhibits an action potential and results in hyperpolarisation

inhibitory post synaptic potential

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46
Q

Is the NMJ always, sometimes or never excitatory?

A

always

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47
Q

what is an excitatory neurotransmitter?

A

membrane potential of postsynaptic neuron depolarised

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48
Q

what is an inhibitory neurotransmitter

A

membrane potential of postsynaptic neuron hyperpolarised or stabilised at resting potential

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49
Q

what are the two types of summation?

A

spatial and temporal

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50
Q

why is summation required?

A

one EPSP is not enough to reach the action potential threshold

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51
Q

what is spatial summation?

A

integration of neurotransmitter signals from several presynaptic neurones to one post synaptic neurone

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52
Q

what is temporal summation?

A

input signals arrive from the same presynaptic cells at different times

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53
Q

how are neurotransmitters removed?
3 methods

A

actively reuptaken back to presynaptic axon terminal
diffuse away from receptor site
enzymatically transformed into inactive substances

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54
Q

Give examples of fast neurotransmitters

A

Ach
glutamate
GABA

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55
Q

Is Ach excitatory, inhibitory or both?

A

Both

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56
Q

Where is Ach excitatory?

A

Skeletal muscle

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57
Q

Where is Ach inhibitory

A

cardiac muscle

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58
Q

what is the main excitatory neurotransmitter

A

GLUT
glutamate

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59
Q

what is the main inhibitory neurotransmitter

A

GABA

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60
Q

Give examples of slow neuromodulators

A

NAd (norepinephrine/ noradrenaline)
DA (dopamine)
Serotonin

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61
Q

which neurotransmitter has a major function at the NMJ?

A

Ach

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62
Q

what are the main types of receptors of Ach?

A

nicotinic and muscarinic

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63
Q

what do nicotinic receptors respond to?

A

ACh and nicotine

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64
Q

which receptor is found at the NMJ?

A

nicotinic

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65
Q

where do muscarinic receptors work?

A

where PNS innervates peripheral organs and glands
e.g salivary glands and

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66
Q

are nicotinic receptors metabotrophic or ionotrophic?

A

ionotrophic

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67
Q

are muscarinic receptors metabotrophic or ionotrophic?

A

metabotrophic

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68
Q

what is the action of AchE

A

Acetylcholinesterase
Breaks down Ach to acetate + choline after function in the synaptic cleft

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69
Q

which neurotransmitter is important in the peripheral heart and CNS?

A

Noradrenaline

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70
Q

what affects noradrenaline?

A

antidepressant drugs
stimulants

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71
Q

what affects serotonin?

A

antidepressant SSRI drugs (e.g Prozac)
ecstasy

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72
Q

which neurotransmitter is vital in basal ganglia?

A

dopamine

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73
Q

where are most dopaminergic neurons?

A

substantia nigra

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74
Q

what affects dopamine?

A

antipsychotics
stimulants
Parkinson’s medication

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75
Q

what is an ascending tract?

A

neural pathway by which sensory information from peripheral nerves is transmitted to the cerebral cortex

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76
Q

how are ascending tracts divided?

A

conscious and unconscious

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77
Q

what comprises conscious tracts?

A

dorsal column-medial lemniscal pathway (DCML) and the spinothalamic tract (anterolateral system)

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78
Q

what comprises unconscious tracts?

A

spinocerebellar tracts

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79
Q

why does the DCML have that name?

A

information travels through dorsal columns in spinal cord then transmitted through medial lemniscus in brainstem

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80
Q

describe the DCML

A

fine sensation detected by receptors
afferent signals carried along 1st oder neurones to dorsal columns and up to medulla where they synapse
second order neurones decussate in medulla and travel up to thalamus where they synapse
3rd order neurones travel through internal capsule to somatosensory cortex

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81
Q

what are the names of the groups of neurones that comprise the DCML?

A

first, second and third order neurones

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82
Q

what does the DCML carry the sensory modalities of?

A

fine touch, vibration, proprioception

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83
Q

what do first order neurones of the DCML do?

A

carry sensory information (regarding touch, proprioception or vibration) from the peripheral nerves to the medulla oblongata

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84
Q

where do DCML first order neurons travel in?
2 versions

A

fasciculus cuneatus for upper limb - lateral part
fasciculus gracilis for lower limb - medial part of dorsal column
this is in the spinal cord

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85
Q

where do second order neurones of the DCML begin?

A

gracile OR cuneate nucleus in medulla

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86
Q

what do second order neurones of the DCML do?

A

receive information from preceding neurones and deliver it to third order neurones in the thalamus

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87
Q

where do second order neurons of the dcml synapse?

A

medulla

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88
Q

where do fibres of second order neurones of the DCML desuccate?

A

medulla oblongata
travel to contralateral thalamus

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89
Q

what do third order neurones of the DCML do?

A

transmit the sensory signals from the thalamus to the ipsilateral primary sensory cortex of the brain

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90
Q

where do signals from the upper limb travel?

A

in the fasciculus cuneatus (the lateral part of the dorsal column)

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91
Q

what vertebral segments count as the upper limb?

A

T6 and above

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92
Q

what vertebral segments count as the lower limb?

A

T6 and below

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93
Q

where do signals from the lower limb travel?

A

in the fasciculus gracilis (the medial part of the dorsal column)

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94
Q

where do fibres from the upper limb synapse?

A

nucleus cuneatus of the medulla oblongata

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95
Q

where do fibres from the lower limb synapse?

A

nucleus gracilis of the medulla oblongata

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96
Q

in the DCML, how does information travel in the spinal cord?

A

via dorsal columns

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97
Q

in the DCML, how does information travel in the brainstem?

A

via the medial lemniscus

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98
Q

what are the two tracts of the anterolateral system?

A

anterior spinothalamic tract
lateral spinothalamic tract
pathways are the same for both tracts
the tracts run alongside each other

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99
Q

what are the names of the groups of neurones in the anterolateral system?

A

first, second and third order neurones

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100
Q

what is the function of the anterior spinothalamic tract?

A

crude touch and pressure

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101
Q

what is the function of the lateral spinothalamic tract

A

pain and temperature

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102
Q

where do the first order neurones of the spinothalamic tracts arise from?

A

sensory receptors in the periphery

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103
Q

where do first order neurones of the spinothalamic tracts travel after they have arisen

A

enter spinal cord

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104
Q

where do first order neurones of the spinothalamic tracts synapse?

A

tip of the dorsal horn

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105
Q

what do second order neurones of the spinothalamic tracts do?

A

carry information from the dorsal horn to the thalamus

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106
Q

where do second order neurones of the spinothalamic tracts desuccate?

A

spinal cord

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107
Q

what do third order neurones of the spinothalamic tracts do?

A

carry information from the thalamus to the ipsilateral primary sensory cortex

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108
Q

describe the spinothalamic pathway

A

nociceptors or thermoreceptors detect pain, temperature or crude touch
1st order neurons carrying these signals enter spinal cord and ascend 2-3 levels before synapsing in dorsal horn of grey matter
2nd order neurones decussate either through anterior or lateral tracts then travel up to thalamus where they synapse
3rd order neurones travel through the internal capsule to the primary somatosensory cortex

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109
Q

what are spinocerebellar tracts?

A

groups of tracts carrying unconscious proprioceptive information from the muscles to the cerebellum

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110
Q

what are the 4 spinocerebellar tracts?

A

posterior spinocerebellar, cuneocerebellar, anterior spinocerebellar, rostral spinocerebellar

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111
Q

where does the posterior spinocerebellar tract carry information from?

A

lower limbs to ipsilateral cerebellum

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112
Q

where does the cuneocerebellar tract carry information from?

A

upper limbs to ipsilateral cerebellum

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113
Q

where does the anterior spinocerebellar tract carry information from?

A

lower limbs to ipsilateral cerebellum

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114
Q

how many times do fibres in the anterior spinocerebellar tract dessucate?

A

twice
meaning they end up where they started so the fibres go to thee ipsilateral cerebellum

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115
Q

spinoreticular tract

A

deep/ chronic pain

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116
Q

where does the rostral spinocerebellar tract carry information from?

A

upper limbs to ipsilateral cerebellum

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117
Q

what are descending tracts?

A

pathways by which motor signals are sent from the brain to the spinal cord

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118
Q

what are the divisions of the descending tracts?

A

pyramidal and extrapyramidal

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119
Q

where do pyramidal tracts originate?

A

cerebral cortex

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120
Q

what do pyramidal tracts do?

A

carry motor fibres to spinal cord and brainstem from cerebral cortex

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121
Q

what are pyramidal tracts responsible for?

A

voluntary control of musculature
makes sense as they come from cerebral cortex

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122
Q

where do extrapyramidal tracts originate?

A

brainstem

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123
Q

what do extrapyramidal tracts do?

A

carry motor fibres to the spinal cord

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124
Q

what are extrapyramidal tracts responsible for?

A

involuntary and autonomic control of musculature
e.g muscle tone, balancee, posture, locomotion

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125
Q

what are the two divisions of pyramidal tracts?

A

corticospinal and corticobulbar

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126
Q

inputs of corticospinal tracts

A

primary motor cortex, premotor cortex, supplementary cortex

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127
Q

describe the path of the corticospinal tracts

A

begins in the cerebral cortex, descends through the corona radiata to the internal capsule, crus cerebri, pons, medulla

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128
Q

in which part of the medulla do the corticospinal tracts divide into 2?

A

caudal

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129
Q

where do corticospinal tracts terminate

A

ventral horn of spinal cord

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130
Q

what is the path of the lateral corticospinal tract?

A

desuccates and then descends, terminating in the ventral horn

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131
Q

what is the path of the anterior corticospinal tracts?

A

remain ipsilateral to the spinal cord, then desuccates and terminates in the ventral horn of the upper thoracic levels

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132
Q

describe corticospinal tracts

A

originate in primary motor cortex
descend through corona radiata and internal capsule to medullary pyramids
90% decussate to bceomee the lateral corticospinal tract
remaining 10% forms the anterior corticospinal tract
anterior tract then decussates through the anterior white commisure
both tracts terminate in the ventral horn

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133
Q

what does the corticospinal tract control?

A

motor control of the body muscles
anterior - axial muscles
lateral - limb muscles

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134
Q

what does the corticobulbar tract control?

A

motor control of the face and neck muscles

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135
Q

what are the two types of neurones in the descending tracts?

A

upper and lower motor neurones

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136
Q

where do the corticobulbar tracts begin?

A

lateral aspect of the primary motor cortex

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137
Q

inputs of the corticobulbar tracts

A

primary motor cortex, premotor cortex, supplementary cortex

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138
Q

path of the corticobulbar tracts

A

primary motor cortex, descend through internal capsule, crus cerebri, brainstem, terminate on motor nuclei of cranial nerves (acting on facial and neck muscles)
synapse with LMNs which carry motor signals to the face and neck

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139
Q

which nerves are the only two to not innervate motor neurons bilaterally?

A

facial and hypoglossal nerve have contralateral innervation

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140
Q

do the upper motor neurones facial and hypoglossal nerves only provide contralateral innervation?

A

hypoglossal - yes
facial - contralateral below the eyes

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141
Q

how can you tell the difference between an upper and lower motor neurone lesion

A

see if there bottom of the face can move (means UMN lesion - stroke rather than Bell’s palsy)

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142
Q

what are the types of extrapyramidal tracts?

A

vestibulospinal, reticulospinal, rubrospinal, tectospinal

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143
Q

where does the vestibulospinal tract arise from?

A

vestibular nuclei

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144
Q

where does the medial reticulospinal tract originate from?

A

pons

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145
Q

where does the lateral reticulospinal tract originate from?

A

medulla

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146
Q

where does the rubrospinal tract originate from?

A

red nucleus

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147
Q

where does the tectospinal tract originate from?

A

superior colliculus

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148
Q

which extrapyramidal tracts desiccate?

A

rubrospinal and tectospinal

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149
Q

role of vestibulospinal tracts

A

balance and posture

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150
Q

role of medial reticulospinal tracts

A

voluntary movement and increasing muscle tone

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151
Q

role of lateral reticulospinal tracts

A

inhibits voluntary movement and reduces muscle tone

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152
Q

role of rubrospinal tracts

A

fine control of hand movements
originate from rd nucleus

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153
Q

do rubrospinal or tectospinal tracts enter the spinal cord after dessucating?

A

tectospinal

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154
Q

role of tectospinal tracts

A

coordinates movements of the head in relation to vision stimuli

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155
Q

are there synapses in the descending pathways?

A

no
all the neurons within the descending motor system are UMNs, and they synapse with a LMN

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156
Q

what does the ANS innervate?

A

smooth and cardiac muscle, glands

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157
Q

what does the somatic nervous system innervate?

A

skeletal muscle

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158
Q

which neurotransmitter do somatic nerves use?

A

ACh

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159
Q

do somatic efferent nerves have one or two axons between the CNS and skeletal muscle cell?

A

one

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160
Q

where are cell bodies of the somatic nervous system?

A

brainstem or ventral horn of spinal cord

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161
Q

do somatic efferent neurons synapse from the CNS to muscle?

A

no

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162
Q

what is the only neurotransmitter for somatic efferent neurones to use?

A

Ach - only excitatory

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163
Q

how many axons do autonomic efferent neurones use?

A

2 (pre and post ganglionic)

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164
Q

what neurotransmitters do preganglionic neurones use?

A

always Ach

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165
Q

what neurotransmitters do postganglionic neurones use?

A

Ach - excitatory
NAd - inhibitory

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166
Q

what segment of the spinal cord supplies sympathetic innervation?

A

T1-L2
thoraco-lumbar

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167
Q

where does a sympathetic neurone synapse

A

lateral horn

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168
Q

do sympathetic neurones have a long or short preganglionic axon?

A

short

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169
Q

do parasympathetic neurones have a long or short preganglionic axon?

A

long

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170
Q

functions of the autonomic nervous system

A

thermoregulation, exercise, digestion, competition, sexual function

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171
Q

where are the nuclei of the parasympathetic cranial nerves located?

A

brainstem

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172
Q

which cranial nerves are parasympathetic?

A

10,9,7,3 (remember by 1973)

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173
Q

what is the role of cranial nerve 10 in a parasympathetic response?

A

decreases heart rate, vasoconstriction, increases GI motility

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174
Q

which types of receptor and neurotransmitters are used in the parasympathetic nervous system?

A

Ach to nicotinic
then
Ach to muscarinic

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175
Q

which types of receptor and neurotransmitters are used in the sympathetic nervous system?

A

Ach to nicotinic
then
NAd to adrenergic

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176
Q

what are the roles of cranial nerves 7 and 9 in a parasympathetic response?

A

9 - swallowing
7 - salivary glands

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177
Q

what is the role of cranial nerve 3 in a parasympathetic response?

A

pupil constriction

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178
Q

what is the enteric nervous system?

A

involved with the GI tract
can operate independently (autoregulation)

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179
Q

what is a motor unit?

A

a SINGLE motor neuron and all the muscle fibres it innervates

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180
Q

what happens to the adjacent motor units when on his damaged?

A

get bigger

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181
Q

where does an UMN travel from?

A

motor cortex to spinal cord

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182
Q

where does a LMN travel from?

A

spinal cord to muscle

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183
Q

what are the consequences of an UMN lesion?

A

hypertonia
hyperreflexia
spasticity
positive Babinski sign
clonus

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184
Q

what is a positive Babinski sign?

A

touch sole of foot with object
foot’s big toe extends rather than flexes

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185
Q

consequences of a LMN lesion

A

hyporeflexia
hypotonia
fasciculations (small twitch)
muscle atrophy

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186
Q

can a muscle cell be innervated by more than one neurone?

A

no

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187
Q

can a neurone innervate more than one muscle cell?

A

yes

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188
Q

what is an end plate potential?

A

voltages which cause depolarization of skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction.

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189
Q

what is a muscle spindle?

A

proprioceptors that consist of intrafusal muscle fibers enclosed in a sheath
intrafusal + stretch receptor

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190
Q

where are muscle spindles found and what do they do?

A

deep in muscle, detect stretch

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191
Q

what is the efferent supply of muscles?

A

by gamma (Y) neurones

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192
Q

what is the afferent supply of muscles?

A

1a fibres

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193
Q

what are Golgi tendons?

A

tension receptors

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194
Q

what fibres do Golgi tendons associate with?

A

1b fast fibres

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195
Q

what spinal nerve segments does the patellar reflex test?

A

L2-L4

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196
Q

describe the patellar reflex

A

patella knocked
activates stretch receptors in all knee
1a from intrafusal fibres to CNS (spinal cord)
A) monosynaptic excitatory stimulation of quadriceps - knee jerk (extension)
B) polysynpatic - inhibition of flexors of knee, excitation of synergistic muscles at knee
1b from Golgi tendon to CNS
C) polysynaptic inhibition of knee jerk when too much stretch detected (prevents overextension and injury)
inverse myotactic reflex

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197
Q

what is a motor unit?

A

an alpha motor neuron and all the extrafusal skeletal fibres it innervates

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198
Q

what is the effect of having an alpha motor neurone innervating fewer skeletal fibres?

A

finer regulation

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199
Q

how are motor neurones somatotrophically organised in the spinal cord?

A

alpha motor neurones in the lateral portion control distal muscle
alpha motor neurones in the medial portion control proximal muscle

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200
Q

what is the spinothalamic tract?

A

sensory tract that carries nociceptive, temperature, crude touch, and pressure from our skin to the somatosensory area of the thalamus
part of the anterolateral system

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201
Q

function of nociceptors

A

sense pain

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202
Q

function of the anterior spinothalamic tract

A

crude touch, pressure, slow pain

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203
Q

function of the lateral spinothalamic tract

A

pain and temperature

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204
Q

are alpha fibres myelinated?

A

yes

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205
Q

are C fibres myelinated?

A

no

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206
Q

analgesia vs anaesthetic

A

analgesia
- selective pain suppression
- consciousness not affected

anaesthetic
- total pain suppression
- consciousness can be affected

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207
Q

Parkinson’s

A

loss of substantia nigra
cannot initiate movement

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208
Q

Myesthenia gravis

A

ACh at neuromuscular junction blocked
muscle weakness

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209
Q

berry aneurysms

A

caused by weakened blood vessel

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210
Q

Duchennes

A

X linked
muscular degradation
recessive

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211
Q

Brown Sequard

A

hemisectional spinal cord compression
e.g lesion below medulla and above spinothalamic decussation
- ipsilateral motor dysfunction
- ipsilateral touch, vibration, proprioception and two point discrimination dysfunction
- contralateral pain, temperature and crude touch dysfunction

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212
Q

Huntington’s

A

low GABA
high dopamine
opposite of Parkinson’s, too much overshooting movement
full penetrance, autosomal dominant, anticipation

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213
Q

multiple sclerosis

A

myelin scarring

214
Q

embryology of the brain

A

after week 3, gastrulation
- formation of trilaminar disc
ectoderm differentially mitoses
neural groove formed
neural tube formed
neural crest cells lateral to neural tube - differentiate into brain and CNS

215
Q

what is the prosencephalon?

A

forebrain

216
Q

what is the mesencephalon?

A

midbrain

217
Q

what is the rhombencephalon?

A

hindbrain

218
Q

what is the prosencephalon divided into?

A

telencephalon and diencephalon

219
Q

what comprises the telencephalon?

A

cerebral hemispheres and basal ganglia

220
Q

what comprises the diencephalon?

A

thalamus, sub thalamus, hypothalamus, epithalamus

221
Q

what comprises the rhombencephalon?

A

pons, cerebellum, medulla oblongata

222
Q

what macromolecules form the myelin sheath?

A

lipid and protein

223
Q

when does myelination begin?

A

in utero
3rd trimester

224
Q

does myelination appear as white or grey matter?

A

white

225
Q

which neurons tend to be unmyelinated

A

post ganglionic autonomic fibres
olfactors neurones
interneurones

226
Q

Guillain-Barre Syndrone

A

rapid onset of muscle weakness
autoimmune damage to PNS
myelin sheath damaged
pain and weakness

227
Q

space between membranes of pre and post synaptic membranes

A

synaptic cleft

228
Q

end of axon

A

axon terminal

229
Q

types of synapse, and which is more common

A

chemical and electrical
chemical is more common

230
Q

supporting cells of the nervous system

A

glial cells

231
Q

type sof glial cells

A

astrocytes, oligodendrocytes, and microglial cells

232
Q

describe chemical synapses

A

plasma membranes of pre and postsynaptic cells are joined by synaptic cleft
axon ends in axon terminal
synaptic cleft prevents direct propagation of the current
signals are transmitted via chemical messenger
synpases are covered by astrocytes, essential for reuptake of neurotransmitter

233
Q

describe electrical synapses

A

plasma membranes of pre and postsynaptic cells are joined by gap junctions
local currents flow directly across junction
depolarises membrane of 2nd neuron to threshold potential
very rapid

234
Q

where do we find electrical synapses?

A

brainstem neurons e.g hypothalamus for hormone secretion

235
Q

which ion causes neurotransmitter release?

A

calcium

236
Q

describe neurotransmitter release

A

voltage gated calcium channels open when action potential reaches pre-synaptic terminal
vesicles move to release sites and fuse with pre-synaptic membrane
exocytosis of neurotransmitter

237
Q

two types of post-synaptic membrane receptors

A

ionotrophic and metabotrophic

238
Q

nature of ionotrophic and metabotrophic receptors

A

ionotrophic - ligand gated ion channels
metabotrophic - G protein coupled receptors

239
Q

response of activation of ionotrophic and metabotrophic receptos

A

ionotrophic - ion flux to change cell voltage
metabotrophic - acts via second messengers, causing cellular effects

240
Q

which are faster, ionotrophic or metabotrophic receptors?

A

ionotrophic

241
Q

which are longer acting, ionotrophic or metabotrophic receptors?

A

metabotrophic

242
Q

give examples of uses of neuromodulators

A

learning
development

243
Q

action of local anaesthetics

A

block sodium channels to prevent depolarisation

244
Q

name of neurotransmitters that release ACh

A

cholinergic

245
Q

how is ACh broken down?

A

by acetylcholinesterase into acetate and choline

246
Q

fate of choline after production

A

transported back into presynaptic axon to be reused

247
Q

how many vertebrae in total?

A

33

248
Q

how many spinal nerves?

A

31

249
Q

which spinal cord segments are fused?

A

sacral
coccyx

250
Q

how many cervical vertebra?

A

7

251
Q

which are the two uppermost vertebrae called?

A

C1 - altas
C2 - axis

252
Q

how many thoracic vertebrae?

A

12

253
Q

how many lumbar vertebrae?

A

5

254
Q

how many sacral vertebrae?

A

5 fused to form the sacrum

255
Q

how many coccyx vertebrae

A

4 fused

256
Q

what happens when muscle fibres are depolarised?

A

actin and myosin slide over each other to produce muscle contraction

257
Q

structure of skeletal muscle

A

actin and myosin myofibrils
form muscle fibres
form muscle fasciculi

258
Q

features of cervical vertebrae

A

small vertebral body
transverse foramen
bifid spinous process bar C7
triangula rintervertebral foramen

259
Q

which vertebrae have a transverse foramen, and what is the purpose?

A

cervical
contain vertebral artery and sympathetic chain

260
Q

which is the only cervical vertebra not to have a bifid spinous process?

A

C7

261
Q

prominent spike on C2

A

dens

262
Q

which vertebrae have a circular vertebral foramen?

A

thoracic

263
Q

which vertebrae contain costal facets?

A

thoracic

264
Q

which vertebrae have a triangular vertebral foramen?

A

lumbar

265
Q

which vertebrae have broad and thick spinous processes?

A

lumbar

266
Q

what does the central canal of the spinal cord contain?

A

CSF

267
Q

enlargements of the spinal cord

A

cervical - C3 -T1 to upper limb
lumbar - L1 - S3 to lower limb

268
Q

where does the spinal cord end?

A

L1/L2

269
Q

name for the tapering of the spinal cord to a cone

A

conus medullaris

270
Q

name for the spinal cord tapering to a strand of tisse

A

filum terminale

271
Q

what do axons in the dorsal cord convey?

A

afferent - sensory neurons

272
Q

what do axons in the ventral cord convey?

A

efferent - motor neurons

273
Q

how do cervical spinal nerves leave the spine?

A

1 vertebra higher except for C8 which is below

274
Q

how do thoracic, lumbar and sacral nerves leave?

A

below the corresponding vertebra

275
Q

how many pairs of spinal nerves, and how are they divided?

A

31

8 c
12t
5l
5s
1 coccygeal

276
Q

what surrounds several nerve fascicles?

A

eepineurium

277
Q

what surrounds each fascicle?

A

perineurium

278
Q

what connects axons laterally in a fascicle?

A

endoneurium

279
Q

larger bundles of fascicles

A

funiculi

280
Q

what does silver stain?

A

grey matter black

281
Q

what stains grey and white matter, and what colours? what does this correspond to?

A

grey matter - cell bodies
stained black by silver

white matter - axoms/ myelin
stained black by osmium

282
Q

how many dorsal and ventral horns?

A

2 of each

283
Q

which nerve and spinal segments control penis erection?

A

S2, S3, S4 pudendal nerve

284
Q

ankle, knee, wrist and biceps, triceps reflexes

A

ankle - S1, S2
knee - L3, L4
wrist and biceps - C5, C6
triceps - C7, C8

285
Q

where is the cell body of the first ANS neuron?

A

in the CNS

286
Q

can the ANS be both excitiatory and inhibitory?

A

yes

287
Q

which neurotransmitters are used in the ANS and when?

A

ach before ganglion
ach (excitatory) or noradrenaline (inhibitory) after

288
Q

effects of sympathetic nervous system

A

increased heart rate
vasoconstriction
reduced gastric motility

289
Q

are ejactulation and erection parasympathetic or sympathetic?

A

ejaculation is sympathetic
erection is parasympathetic

290
Q

where is parasympathetic outflow from?

A

brainstem and sacral vertebrae

291
Q

which neurotransmitter is used at the effector for parasympathetic, somatic and sympathetic nerves?

A

para - ACh
sympathetic - NE
somatic - ACh

292
Q

is the preganglionic or post ganglionic nerve of ANS myelinated?

A

pre

293
Q

do parasympathetic or sympathetic neurons have a longer preganglionic axon?

A

parasympathetic

294
Q

what is a motor unit?

A

alpha motor neuron and all the extrafusal skeletal muscle fibres it innervates

295
Q

do medial or lateral alpha motor neurons control distal muscles?

A

lateral

296
Q

what is muscle tone?

A

degree of contraction of a muscle or the proportion of motor units that are active at a time

297
Q

region of muscle fibre directly under the terminal portion of the motor neuron

A

motor end plate

298
Q

junction between the axon terminal and motor end plate

A

neuromuscular junction

299
Q

what is an EPP

A

end plate potential
comparable to EPSP

300
Q

describe the NMJ

A

action potential arrives at axon terminal
plasma membrane depolarised
voltage gated calcium channels open
calcium ions diffuse into the axon terminal
ACh vesicles ruse with the neuronal plasma membrane
ACh diffuses to the motor end plate and binds to cholinergic nicotinic receptors
ion channels in the receptor protein opens
more Na moves in than K out
EPP produced

301
Q

upper motor neuron

A

cell body originates in the cerebral cortex or brainstem
terminates within the brainstem or spinal cord

302
Q

symptoms of upper motor neuron damage

A

hypertonia
hyperreflexia
spasticity
positive babinski’s sign
clonus

303
Q

can a lower motor neuron innervate more than one muscle fibre?

A

yes but not the other way round

304
Q

types of lower motor neuron

A

alpha and gamma

305
Q

function of alpha motor neurons

A

contraction of muscle fibres

306
Q

which motor neurons are somatotrophically organised?

A

alpha

307
Q

which motor neurons exhibit signs of LMN syndrome when damaged?

A

alpha

308
Q

function of gamma motor neurons

A

regulation of muscle tone
proprioception

309
Q

symptoms of LMN damage

A

hypotonia
hyporeflexia
flaccid muscle weakness or paralysis
fasciculation - small involuntary twitches
muscle atrophy

310
Q

function of stretch receptors

A

monitor muscle length and rate of change of muscle length

311
Q

what is a muscle spindle?

A

intrafusal fibres embeddd in muscle - extrafusal fibres

312
Q

what are intrafusal fibres (in muscle spindles) innervated by?

A

gamma motor neurons

313
Q

function of gamma motor neurons in the intrafusal fibres

A

keep the intrafusal fibres at a set length to optimise muscle stretch detection

314
Q

types of stretch receptors

A

nucelar chain and nuclear bag

315
Q

function of nuclear chain receptors

A

respond to how much the muscle is stretched

316
Q

function of muscle bag receptors

A

respond to magnitude and speed of stretching

317
Q

what part of the muscle spindle are contractile?

A

2 ends
centre is non-contractile

318
Q

which part of the spindle is associated with fast type 1a afferent sensory nerves?

A

middle third
non contractile part

319
Q

which part of the spindle is associated with type 2 afferent sensory nerves that are slower conducting?

A

inferior and superior parts

320
Q

what are muscle spindle attached to in paralell?

A

extrafusal fibres

321
Q

what does muscle tension depend on?

A

muscle load
muscle length
degree of muscle fatigue

322
Q

what detects muscle tension?

A

golgi tendon organ

323
Q

what do golgi tendon organs detect?

A

force developed by muscle and resultant change in length

324
Q

what is the Golgi tendon organ?

A

endings of afferent fibres that wrap around collagen bundles in the tendons

325
Q

which fibres run from the golgi tendon organ?

A

afferent 1b sensory nerve fibres
- inhibitory

326
Q

how do golgi tendon organs work?

A

when the muscle is stretched, tension is exerted on the tendon
the bundles straighten and activate the GTO receptor endings

327
Q

what do golgi tendon organs stimulate and inhibit?

A

stimulate motor neurons of the antagonistic muscle
inhibit alpha motor neurons to prevent muscle contraction

328
Q

function of 1b fibres

A

inhibit muscle contraction via inhibiting alpha motor neurons

329
Q

what is the stretch reflex called?

A

myotatic

330
Q

patellar reflex

A

stretch reflex
patellar tendon is tapped
thigh muscle stretch
stretch receptors activation
burst of action potentials in the afferent nerve fibres
stimulation of motor unit
muscle contraction
extension of lower leg

331
Q

is the patellar reflex monosynaptic?

A

yes

332
Q

what is a polysynaptic reflex?

A

at least one interneuron between the afferent and efferent neurons

333
Q

reciprocal innervation

A

afferent nerve fibres end on inhibitory interneurons
when activated, they inhibit the motor neurons of the antagonistic muscle
e.g with the patellar reflex, the neurons that flex the knee would be inhibited

334
Q

withdrawal reflex

A

pain stimulation activates flexor muscles and inhibits extensor muscles
affected limb moves away from harmful stimulus

335
Q

example of withdrawal reflex

A

touching something hot

336
Q

withdrawal reflex in the leg

A

shift in weight
motor neurons to the contralateral extensors aree activated, and the flexors are inhibited

337
Q

acute pain last how long

A

less than 12 weeks

338
Q

how long is chronic pain?

A

over 12 weeks

339
Q

nociceptive pain

A

arises from actual or threatened damage to non-neuronal tissue

340
Q

neuropathic pain

A

caused by primary lesion/ dysfunction of the nervous system

341
Q

pain pathway to brain

A

first order neuron remains ipsilateral? and synapses with second order neuron
second order neuron cell body is in the spinal cord/ brainstem
it decussates and ascends to the thalamus
third order neuron cell body is in the thalamus
axons project to somatosensory cortex

342
Q

internal nociceptors

A

viscera
joints
muscles

343
Q

external nociceptors

A

mucosa
skin
cornea

344
Q

what can cause hyperalgesia?

A

bradykinin
prostaglandin E2

345
Q

what is hyperalgesia?

A

reduced nociceptive action potential threshold
increased sensitivity to pain

346
Q

types of nociceptors

A

alpha delta fibres
C fibres

347
Q

smallest nerve fibres

A

C fibres

348
Q

which nerve fibres have a high activation threshold?

A

alpha delta

349
Q

what type of pain are alpha delta fibres responsible for?
and C fibres?

A

quick and localised pain
slow spread out pain

350
Q

myelination of alpha delta fibres

A

thinly myelinated

351
Q

myelination of C fibres

A

none

352
Q

are alpha delta or C fibres fast?

A

alpha delta

353
Q

what information do alpha delta fibres carry?

A

touch, pressure, temperature

354
Q

what do alpha delta fibres release?

A

glutamate

355
Q

what information do C fibres carry?

A

pain, temperature, touch, pressure, itch

356
Q

what do C fibres release?

A

glutamate and substance P

357
Q

what is substance P and its function?

A

peptide neurotransmitter and vasodilator
remains bound to receptors for a longer time, causing long lasting pain

358
Q

analgesia

A

selective suppression of pain without effects on consciousness

359
Q

anaesthesia

A

uniform suppression of pain
no pain is felt
can cause loss of consciousness

360
Q

brain development

A

fertilisation
morula - 16 cells
blastocyst - over 16 cells
trilaminar disc
- ectoderm
- mesoderm
- endoderm
ectoderm thickens in the midline to form the neural plate in the 3rd week
neural groove formed
groove deepens to form neural tube by end of 4th week

361
Q

where are neural crest cells?

A

lateral to neural plate

362
Q

what do neural crest cells form?

A

ganglia
Schwann cells
adrenal medulla
meninges
dermis
CN 5, 7, 9, 10

363
Q

when do primary and secondary brain vesicles form?

A

5th and 7th week

364
Q

when does the blood brain barrier form?

A

8 weeks

365
Q

cells of blood brain barrier

A

endothelial cells, pericytes, astrocytes

366
Q

when does the neural tube close?

A

end of week 4

367
Q

failure of neural tube to close in spinal cord

A

spina bifida

368
Q

failure of neural tube to close in cephalic region

A

anencephalus

369
Q

functions of frontal lobe

A

thought, memory, reasoning

370
Q

which areas make up Broca’s area?

A

Brodmann’s area 44 and 45

371
Q

only sensation not to relay through thalamus

A

olfactory

372
Q

which gyrus is linked to limbic system?

A

cingulate

373
Q

where is the degree of pain judged?

A

insula

374
Q

grey matter in the midbrain around the cerebral acqueduct

A

periaqueductal grey

375
Q

dorsal striatum

A

caudate nucleus and putamen

376
Q

ventral striatum

A

nucelus accumbens and olfactory tubercle

377
Q

parts of basal ganglia

A

caudate nucleus, putamen, nucleus accumbens, olfactory tubercle, globus pallidus, ventral pallidum, substantia nigra, subthalamic nucleus

378
Q

basal ganglia disorders

A

parkinsons
huntingtons

379
Q

lack of dopamine

A

parkinsons

380
Q

excess dopamine

A

huntingtons

381
Q

Parkinson’s

A

loss of dopaminergic neurons in substantia nigra
spacicity, reduced movement, bradykinesia, tremor

382
Q

parkinson’s treatment

A

L Dopa
corrects dopamine deficiency

383
Q

Huntington’s

A

cag repeats
too little GABA results in too much dopamine
autosomal dominant
full penetrance
dementia and personality change
destruction of the striatum - in particular the caudate nucleus

384
Q

function of basal ganglia

A

posture, motor control, behavior

385
Q

function of limbic system

A

interface between the internal and external environment
adaptive behavior, emotional responsiveness

386
Q

parts of limbic system

A

cingulate gyrus, hippocampus, parahippocampal gyrus, anterior perforated substance, septal nuclei, uncus, amygdala

387
Q

what connects the parts of the limbic system

A

papez circuit

388
Q

function of amygdala

A

fear and reward

389
Q

function of septal nuclei

A

reward and reinforcement

390
Q

function of hippocampus

A

short term memory, spatial memory, navigation

391
Q

function of papez circuit

A

emotional expression and memory

392
Q

what does the papez circuit start and end with?

A

hippocampus

393
Q

papez circuit

A

hippocampal formation, fornix, mamillary bodies, mammilothalamic tract, anterior thalamic nucleus, cingulum, entorhinal cortex, hippocampal formation

394
Q

a disease of the papez circuit/ limbic system

A

Alzheimers

395
Q

where is memory stored?

A

prefrontal cortex

396
Q

function of hypothalamus

A

homeostasis

397
Q

explicit memory

A

conscious

398
Q

types of explicit memory

A

episodic and semantic

399
Q

what is episodic memory?

A

autobiographical
hippocampus and midbrain

400
Q

what is semantic memory?

A

knowledge
frontal temporal lobe

401
Q

hat is implicit memory?

A

unconscious
skills and habits - cerebellum and basal ganglia
conditioned reflexes - cerebellum
emotion - amygdala

402
Q

functions of cerebellum

A

motor control of equilibrium
maintenance of posture and balance
maintenance of muscle tone
coordination of voluntary movements

403
Q

cerebellar tracts

A

corticopontocerebellar
vestibulocerebellar
spinocerebellar

404
Q

where does the corticopontocerebellar tract receive information from and signal to?

A

primary motor cortex
middle cerebellar peduncle

405
Q

where does the vestibulocerebellar tract receive information from and signal to?

A

vestibular impulses from labyrinths via the vestibule nucleus
to the inferior cerebellar peduncle

406
Q

where does the spinocerebellar tract recieve information from and signal to?

A

sensory input for balance and position sense
superior cerebellar peduncle

407
Q

layers of cerebellum out to in

A

molecular, purkinje, granule

408
Q

symptoms of cerebellar damage

A

jerky and erratic movement

409
Q

on which aspect of the midbrain are the colliculi and pineal?

A

dorsal

410
Q

where do each pair of cranial nerves emerge?

A

The oculomotor nerve (III) and trochlear nerve (IV) emerge from the midbrain, the trigeminal (V), abducens (VI), facial (VII) and vestibulocochlear (VIII) from the pons, and the glossopharyngeal (IX), vagus (X), accessory (XI) and hypoglossal (XII) emerge from the medulla.

411
Q

where is the locus coerulus?

A

lateral floor of 4th ventricle

412
Q

function of locus coerulus

A

sleep-wake
attention and memory
stress
emotions

413
Q

fissurres of the medulla

A

anterior median fissure
ventrolateral sulcus
posterolateral sulcus

414
Q

what decussates at the medulla?

A

pyramids
DCML

415
Q

where are the olives?

A

medulla

416
Q

function of the medulla

A

autonomic
ventilation

417
Q

which cranial nerves are parasympathetic?

A

1973
10th 9th 7th 3rd

418
Q

innervation and function of hypoglossal
exit foramen

A

intrinsic and extrinsic muscles of the tongue
movement of the tongue
hypoglossal canal

419
Q

how to tell which cranial nerves are sensory, motor or both

A

some say marry money but my brother says big brains matter more

420
Q

innervation and function of accessory nerve
exit foramen

A

sternocleidomastioid and trapezius
movement of head and shoulders

421
Q

innervation and function of vagus
exit foramen

A

a lot
pharynx, larynx, trachea, oesophagus
viscera
soft palate
general sensation
chemoreception
speech
swallowing
cardiac muscle innervation
and more
jugular foramen

422
Q

innervation and function of glossopharyngeal
exit foramen

A

pharynx, posterior third of tongue, eustacian tube, middle ear, carotid body, carotid sinus, stylopharyngeus, parotid
taste, chemoreption, baroreception, swallowing, salivation
jugular foramen

423
Q

function of vestibulocochlear nerve

A

innervates vestibular apparatus
position and movement of head

424
Q

innervation of tensor tympani

A

mandibular division of trigeminal

425
Q

function of third division of trigeminal

A

tension on tympanic membrane

426
Q

innervation of lacrimal glands

A

facial

427
Q

innervation of submandibular, sublingual and parotid

A

maxillary division of trigeminal

428
Q

what passes through cavernous sinus?

A

O TOM CAT
oculomotor
trochlear
ophthalmic trigeminal
maxillary trigeminal
internal carotid
abducens

429
Q

function of cornea

A

transmission of light
refraction

430
Q

structure and function of sclera

A

white capsule around the eye except anterior surface where it is cornea
protection
continuation of dura and cornea

431
Q

middle layer of eye

A

uvea

432
Q

iris

A

specialised section of choroid
controls pupil size
sphincter muscles make pupil smaller
dilator muscles make pupil larger
give eye colour

433
Q

ciliary body

A

smooth muscle control accommodation
innervated by PNS
glandular epithelium - produces aqueous humour
behind iris

434
Q

where is the pars plana?

A

iris sclera junction

435
Q

choroid

A

nutrition of the outer retina
heat sink
darkly pigmented to absorb stray photons
highly vascular

436
Q

where is vitreous humour produced?

A

retina

437
Q

where is light focused onto in the retina?

A

fovea centralis
this is in the middle of the macula lutea

438
Q

what does the macula lutea have a high concentration of?

A

cones

439
Q

where are the photoreceptors?

A

retinal pigment epithelium

440
Q

function of rods

A

dim lighting, peripheral vision

441
Q

function of cones

A

colour vision

442
Q

layers of tear film, source and function

A

anterior - lipid from meibomiun gland - prevent evaporation
middle - aqueous from lacrimal glands - prevents infection
posterior - mucus from goblet cells - hydrophilic, even distribution of tear film

443
Q

aqueous humour

A

produced by ciliary epithelium in ciliary body
maintains intraocular pressure

444
Q

vitreous humour

A

collagen matrix
hyaluronic acid and water

445
Q

what is intraocular prressure maintained at?

A

12-20mmHg

446
Q

which parts of the eye refract light?

A

cornea and lens

447
Q

photon pathway

A

tear film, cornea, aqueous humour, lens, vitreous humour, ganglion ceell, amacrine cell, bipolar cell, horizontal cell, cone, rods, pigmented epithelium (absorption of excess photons)

448
Q

blood supply to the eye

A

internal carotid
- opthalamic artery, central retinal artery, ciliary arteries
external carotid
- facial artery supplies medial lid and orbit

449
Q

in which bone is the optic canal?

A

sphenoid

450
Q

extracranial visual pathway

A

optic nerve formed by convergence of axons from retinal ganglion cells
RGCs receive impulses from rods and cones
optic nerve leaves via optic canal

451
Q

ntracranial visual pathway

A

optic chiasm in middle cranial fossa
nasal fibres cross
temporal fibres do not cross
optic tracts travel to lateral geniculate nucleus in the thalamus and fibres synapse
axons from LGN carry visula information via optic radiations
to visual cortex

452
Q

Bauman’s loops

A

fibres from superior retinal quadrant
this is the inferior visual field
parietal lobe

453
Q

meyers loop

A

fibres from inferior retinal quadrant
this is the superior visual field
temporal lobe

454
Q

intortion

A

internal rotation towards midline

455
Q

extortion

A

external rotation away from midline

456
Q

which ocular muscles are controlled by nervees other than oculomotor?

A

LR6SO4

457
Q

damage to left optic nerve

A

left eye blindness

458
Q

damage to optic chiasm

A

bitemporal hemianopia

459
Q

damage to left optic tract

A

loss of temporal vision of left eye and nasal vision of right eye

460
Q

damage to left Meyers loop

A

loss of superior nasal field of left eye and superior temporal field of right eye
stuff in upper right of eye diagrams pretty much

461
Q

two pathways of the auditory system

A

lemniscal and non-lemniscal

462
Q

organ of Corti

A

organ of the inner ear located within the cochlea which contributes to audition. The Organ of Corti includes three rows of outer hair cells and one row of inner hair cells.

463
Q

which nerve carries information from the organ of corti?

A

vestibulocochlear

464
Q

lemniscal pathway

A

carries auditory information to the primary auditory cortex

465
Q

non-lemniscal pathway

A

unconscious perception
do not lead to primary auditory cortex

466
Q

spiral ganglion

A

cell bodies of first order neurons located here

467
Q

wherre does the spiral ganglion recieve information from?

A

organ of corti - hair cells

468
Q

where do first order auditory neurons synapse?

A

ipsilateral cochlear nuclei

469
Q

auditory pathway

A

spiral ganglion receives information from organ of corti
vestibulocochlear nevre enters via internal acoustic meatus
travels to brainstem
first order neurons synapse at the ipsilateral cochlear nuclei
fibres of cochlar nerve bifurcate
all fibres arrive at the inferior colliculus
fibres project to ipsilateral medial geniculate body in the thalamus
projections process to primay auditory complex in temporal lobe
organised tonotrophically

470
Q

do non-lemniscal pathways lead to primary auditory cortex?

A

no

471
Q

label the ear

A

.

472
Q

pathway of venous drainage starting at the great cerebral vein

A

great cerebral vein, straight sinus, transverse sinus, sigmoid sinus, internal jugular vein, jugular vein, brachiocephalic vein (formed by uniting with subclavian), SVC

473
Q

confluence of sinuses

A

straight sinus and superior saggital sinus

474
Q

lining of ventricles

A

ependyma

475
Q

what are vertebral arteries a branch of?

A

subclavian

476
Q

upper border of thyroid cartilage

A

C4

477
Q

whee does the common carotid bifurcate?

A

upper border of thyroid cartilage
C4

478
Q

two other extraocular muscles innervated by CN3

A

levator palpebrae superioris
sphincter pupillae

479
Q

motor innervation of stapedius

A

facial

480
Q

which glands does the facial nerve innervate?

A

sublingual, submandibular, lacrimal

481
Q

innervation and function of CN8

A

cochlea and vestibular apparatus
hearing and proprioception of the head
balance

482
Q

sensory, motor and paraympathetic innervation of glossopharyngeal

A

sensory
- posterior third of tonguee
- middle ear
- pharynx
- carotid bodies

motor
- stylopharyngeus

parasympathetic
- parotid

483
Q

what innervates carotid body?

A

glossopharyngeal

484
Q

what innervates aortic body?

A

vagus

485
Q

what nnervates external ear?

A

vagus

486
Q

which nerve is responsible for swallowing and speech?

A

vagus

487
Q

functions of glossopharyngeal

A

general sensation, tase, chemo/ baro reception, swallowing (motor), salivation

488
Q

which region of the vertebrae rotates the most?

A

thoracic

489
Q

which region has the least capacity for flexion?

A

thoracic
due to ribcage

490
Q

components of intervertebral discs

A

inner nucleus pulposus
outer annulus fibrosus - collagen

491
Q

what does the ligamentum flavum connect?

A

laminae of adjacent vertebrae

492
Q

where does the spinal cord end in
an adult
birth
an embryo

A

L2
L3
runs entire length of vertebral column

493
Q

where would you insert a lumbar puncture?

A

L3/L4 n subarachnoid space

494
Q

where do the internal carotid arteries enter the skull?

A

carotid foramina

495
Q

cauda equina

A

spinal nerves from lower spnal cord that hang obliquely downwards

496
Q

dermatome

A

area of skin with a sensory nerve supply from a single root of the spinal cord

497
Q

thumb dermatome

A

C6

498
Q

knee dermatome

A

L3

499
Q

biig toe dermatome

A

L5

500
Q

4 ascending tracts

A

DCML
spinothalamic
spinocerebellar
spinoreticular

501
Q

where is the 3rd ventricle formed in the embryo?

A

diencephalon

502
Q

pluripotent stem cells within nural folds

A

neural crest cells

503
Q

which vitamins ensure the neural tube fuses?

A

B9 - folic acid
B12

504
Q

substances within CSF

A

protein
urea
glucose
salts

505
Q

endorphins

A

peptides with opiate like effects
inhibit substance p release

506
Q

how long does the refractory period last?

A

5-10ms

507
Q

which meningeal layers are vascularised?

A

dura and pia
not arachnoid

508
Q

does the function of a muscle affect how namy muscle fibres there are?

A

yes
fingertips have fewer fibres for greater resolution of movement

509
Q

where are UMN cell bodies?

A

primary motor cortex

510
Q

where are LMN cell bodies?

A

brain stem or spinal cord

511
Q

where do the optic tracts terminate?

A

lateral geniculate body in the thalamus

512
Q

which bones make up the ossicular chain?

A

malleus, incus and stapes
MIS
stapes is attached to oval window

513
Q

smallest bone in the body

A

stapes

514
Q

function of ossicles

A

transmit vibrations from tympanic membrane to oval window

515
Q

which muscles change the stiffness of the ossicular chain?

A

stapedius and tensor tympani

516
Q

innervation of stapedius

A

facial

517
Q

innervation of tensor tympani

A

trigeminal

518
Q

function of stapedius and tensor tympani

A

control the mobility of malleus and stapes
protect the inner ear from loud noises

519
Q

two ear windows

A

oval and round

520
Q

function of the round window

A

vibrates with opposite phase to vibrations entering the inner ear through the oval window
moves fluid in the cochlea which means that hair cells of the basilar membrane will be stimulated and audition occurs

521
Q

function of the vestibular system

A

balance and spatial orientation

522
Q

what are the vestibular apparatus?

A

otolithic organs - utricle and saccule
semicircular canals

523
Q

what do semicircular canals detect?

A

angular acceleration

524
Q

what do otolithic organs detct?

A

linear acceleration
changes in head position relative to gravity

525
Q

where are vestibular hair cells?

A

utricle, saccule, 3 ampulla at the base of the semicircular canals

526
Q

function of vestibular hair cells

A

detect changes in motion and position of the head

527
Q

function of cochlea

A

sound

528
Q

what do the semicircular ducts contain?

A

fluid

529
Q

what do the semicircular canals empty into?

A

sac called the utricle

530
Q

where are the sense organs for balance?

A

semicircular ducts and utricle

531
Q

where is information from the semicircular ducts sent to?

A

CN8 then nuclei in the medulla
vestibular nuclei

Phase 1 flashcards (27 decks)

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