Theme 2 - Sensory Inputs and Motor Outputs Flashcards Preview

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Flashcards in Theme 2 - Sensory Inputs and Motor Outputs Deck (147)
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1

An ipsilateral lesion to the dorsal medial leminscus tract spinal cord (for example in MS) will result in what?

loss of propriception on the same side

2

What is a loss of coordination and balance without visual cues known as?

sensory ataxia

3

What is the test/sign for sensory ataxia?

Rombnerg's sign - severe swaying on standing with eyes closed and feet together

4

An ipsilateral lesion to the white matter anterolateral column will result in what?

Loss of pain, temperature and crude touch on opposite side

5

What will an ipsilateral lesion to the posterior spinocerebellar tract cause?

Loss of lower limb muscle coordination on the same side

6

3 symptoms associated with upper motor neuron disease

Spastic paralysis
Overactive tendon reflexes
No significant atrophy

7

If there is a degeneration of upper motor neurons above the pyramids which side will it mainly affect?

opposite side

8

Three features of lower motor neuron disease

Flaccid paralysis
No tendon reflexes
Atrophy

9

What does amyotrophic lateral sclerosis (Lou Gehrigs disease) affect?

progressively and selectively affects both lower and upper motor neurons

10

What three things will be affected in anterior cord syndrome?

Bilateral lower motor paralysis and atrophy (lower motor neurons
Bilateral spastic paralysis descending anterior tracts
Loss of pain, temperature and fine touch

11

What sensation remain intact during anterior cord syndrome

proprioception
tactile descrimination
vibration

12

5 effects of Brown-Sequard hemisection?

ipsilateral paralysis and atrophy (lower motor)
ipsilateral spastic paralysis (upper motor)
ipsilateral anesthesia at lesion level (dorsal root)
ipsilateral loss of proprioception
contralateral loss of pain, temp and light touch

13

4 Effects of complete cord transection

Complete loss of sensation and voluntayy movement below transection site
Bilateral lower motor neuron paralysis and atrophy
Bilateral spastic paralysis
Bladder and bowel non voluntary

14

Outline the motor control hierarchy in terms of associated areas of the brain (high to low)

Association areas of neocortex, basal ganglia
Motor cortex/cerebellum
Brainstem/spinal cord

15

What are the 5 descending motor pathways?

Corticospinal
Rubrospinal
Reticulospinal
Tectospinal
Vestibulospinal

16

Where does the corticospinal tract begin, dessucate and synapse?

Motor cortex
Medullary pyramids
Lateral CS tract

17

Where does the Rubrospinal tract begin, dessucate and predominantly end up?

Red nuclei in midbrain
Medulla
Cervical junction

18

Where does the vestibular spinal tract begin and where do they go?

Medial and Lateral vestibular nucleus in brainstem
Med - neck muscles
Lateral - Limbs

19

What does the vestibular muscles facilitate?

Keeping a steady gaze
Steady balance and posture

20

From where does the Tectospinal tract originate?

Superior and inferior colliculi

21

What does the tectospinal tract from each collucili help you to do?

Superior collucili - instant neck and head muscle responce to fast visual stimulus

22

Where does the reticulospinal tract originate and what is it associated with?

Reticilum (back) of brainstem and aid with posture

23

What descending pathways are associated with control of head and neck movements?

Tectospinal and medial vestibulospinal

24

What descending pathways are associated with control of limb extension?

Lateral vestibulospinal and reticulospinal

25

What descending pathway is associated with flexion of upper limbs?

Rubrospinal

26

In a coma pt, what type of posturing will result in them flexing their arm and either flexing or extending their leg?

decorticate posturing

27

In a coma pt what type of posturing will result in them extending both their arms and legs?

decerebrate

28

What indication do decorticate and decerebrate posturing give about the location of the lesion?

decorticate - above red nucleus (Rubrospinal tract intact)
decerebrate - below red nucleus

29

Does the babinski reflex indiacate an upper or power motor neuron lesion?

Upper

30

Where does the corticobulbar pathway go from/to?

motor cortex to cranial nerves

31

What is the difference in terms of lesion localisation and facial palsy between a stroke and Bells palsy?

Stroke - upper motor neurone, contralateral lower half
Bell's - lower motor neurone, ipsilateral, full half

32

What is abulia?

Loss or impairment of the ability to make decisions or act independently

33

A stroke associated with what type of artery is most likely to result in abulia?

Anterior cerebral

34

What type of seizure is associated with a "march" of symptoms?

Jacksonian

35

What can damage to the posterior parietal cortex result in?

neglect - can perceive but not attend

36

What pathways are associated with the posterior parietal cortex?

somatosensory afferent
visual afferent

37

Damaged to the interconnections between the sensory and motor coordination areas is likely to result in what?

Apraxia

38

What term describes a difficulty in sequencing and execution of movements?
Apraxia
Aphagia
Anosia

Apraxia

39

What is the difference between ideational and ideomotor apraxia and what areas of the brain are they assocoated with?

Ideational (parietal) cannot report sequence
Ideomotor (SMA) - cannot use the tool

40

What condition is best described as sustained muscle contractions, usually producing twisting and repetitive movements or abnormal postures or positions.
If only occurs with certain actions, said to be ‘task specific’.

dystonia

41

3 functions of the cerebellum

Maintenance of balance and posture
Coordination of voluntary movements
Motor learning

42

What are the 3 main inputs into the cerebellum and what area do they feed into?

vestibulocerebellum - flocculonoddular
cerebrocerebellum - hemispheres
spinalcerebellum - vermis

43

to what nuclei do the vermis, paravermis and hemispheres link?

vermis - fastigial
paradermis - interposed
hemispheres - dentate

44

To what other areas of the brain are the cerebellar fastigial, interposed, dentate and vestibular nuclei linked to?

Fastigial - motor
interposed - motor
dentate - motor planning
vestibular - balance and eye movements

45

4 Steps of the spinocerebellum loop

spinocerebellar tract
vermis
fastigial/interposed nuclei
reticulo/vestibularspinal tract

46

6 steps of the corticocerebellum loop

cortex
pons
hemispheres
dendate nucleus
thalamus
cortex

47

4 steps of vestibulococlear loop

vestibulocochlear
fluculonodular node
vestibular nuclei
eyes/neck muscles

48

What are the 3 cerebellar peduncles and are they inputs or outputs?

Superior - output
Middle - input
Inferior - input

49

What tracts input via the inferior and middle cerebral peduncle?

inf - Spinocerebellar
mid - corticocerbellar

50

What tracts output via the superior cerebral peduncle?

vestibulocerebellar
corticocerebellar
spinocerebellar

51

5 effects of lesions on the cerebrocerebellar pathway

dysmetria
dysnergia
disdisdochokinesia
intentional tremor
dysarthria

52

What term is defined as the inability to stop a movement in time?

Dysmetria

53

What term is defined as decomposition of complex movements?

Dsynergia

54

What term is defined as reduced ability to perform rapidly alternating movements?

Dysdiadochokinesia

55

What is an intentional tremor?

tremor arising when trying to perform a goal-directed movement

56

What term is defined as incoordination in the respiratory muscles, muscles of the larynx, etc. Uneven speech strength and velocity?

Dysarthria

57

What are the 2 effects of lesions on the vestibulo occular pathway?

Nystagmus
Inability to fixate when moving

58

What is the effect of lesion on the spinocerebellar pathway?

gait ataxia

59

What term is defined as involuntary, rhythmical, repeated oscillations of one or both eyes, in any or all directions of view?

Nystagmus

60

What two types of fibre input into the cerebellum and where do they come from?

Mossy fibres - spinal tract
climbing fibres from - inferior olive of medulla

61

Describe/draw the cerebellar circuit in terms of
mossy fibres,
climbing fibres
granule cell
parallel cell
purkunje cell

mossy to granule to parallel to perkunje
climbing to perkunje

62

Give 2 genetic causes of cerebellar dysfunction

Frederich’s ataxia
Spinocerebellar degeneration

63

5 causes of acquired symmetrical ataxia

Alcohol
drugs
metabolic (B12)
degenerative
Immune

64

What 3 types of tissue are innervated by the ANS?

Smooth muscle
cardiac
glands

65

What are the 3 divisions of the ANS?

sympathetic
parasympathetic
enteric

66

In terms of the CNS what are anatomical divisions of the sympathetic and parasympathetic nervous systems?

Para - brainstem, S1-S4
sym - T1 - L2

67

The ANS works via a disynaptic pathway in all but one effector organ, which one?

adrenal glands

68

Explain/draw the disynaptic pathway i terms of
cranial nerve
ganglion
effector organ
myelenated
unmylenated

as described

69

What is the main neurotransmitter in the preganglionic ANS?

Ach

70

What are the three ascending pathways in the spinal cord?

Spinothalamic (anterolateral)
spinocerebellar
dorsal columns (medial lemniscus)

71

What neurotransmitters used (post ganglion) by the sympathetic and para sympathetic nervous system?

sym Noradrenaline/NE
para - Ach

72

What type of receptors are employed by the sympathetic and para sympathetic nervous system pre and post ganglion?

ganglion - nicotinic Ach
post - G protein metabotropic (except adrenal medulla)

73

What are the two plexuses that make up the enteric nervous system and what do they regulate?

Auerbach's - muscle contraction
Meissner's - secretions

74

What are the two possible pathways of the preganglionic fibres once they enter the sympathetic trunk?

Synapse in ganglion
Pass through ganglion in splancnic nerves and synapse in prevertebral ganglia

75

Post ganglionic fibres are more numerous than preganglionic fibres, what is the advantage of this?

It allows for a mass response

76

What are the two possible pathways of the POSTganglionic fibres once they exit the sympathetic trunk?

To periphery via grey rami
To viscera via plexuses

77

What are the 3 ganglia in the cervical trunk, and what's special about one of them?

Superior
Middle
Inferior - fussed to T1 ganglia to form stellate

78

What are the 3 possible routes for the postganglionic fibres in the cervical sympathetic trunk?

via grey rami to spinal nerves and upper limbs
piggy back down carotid artery to heart
Or up internal/external carotid to head

79

What condition is the disruption of sympathetic nervous supply to the head?

Horners syndrome

80

What are the 3 possible routes of the postganglionic fibres in the thoracic sympathetic trunk?

grey rami to spinal nerves
medial branches to heart and lungs
splancnic nerves to abdomen

81

What cranial nerves are associated with the parasympathetic nervous system

III
VII
IX

82

5 sensations of pain

Sharp stab
Deep Ache
Burning
Freezing Itch

83

3 classifications of pain

Nociceptive
Infalmmatory
Neuropathic

84

Describe A alpha and A beta fibres in terms of myelenation, diameter and sensation conveyed

Myelenated
Thick
Light touch, proprioception

85

Describe A delta fibres in terms of myelenation, diameter and sensation conveyed

Thinly myelenated
medium
light touch, temperature nociception

86

Describe C fibres in terms of myelenaations, diameter, ans sensation

Unmyelenated
thin
temperature, nociception

87

What are the types of nerve fibre involved in pain transmission

Alpha delta
C fibres

88

What type of pain is conveyed by each type of pain fibres?

Alpha delta - sharp prick
C fibres - dull ache

89

At what point on the pain transduction graph is the first and second response?

First large peak = A beta
First small peak = first response from A delta
last small peak = second response from C fibres

90

Which transient potential receptor is responsible for detecting heat?

TRPV1

91

Via what tract does pain ascend the spinal cord?

spinothalamic tract

92

How does referred pain occur with regard to synapsing of neurons?

because the first order neurons of the vicera and cutaneous synapse on the same second order neuron

93

What 2 regions involved in the descending regulation of pain?

PAG (midbrain)
Raphe nucleus (medulla)

94

What effect can the Raphe nucleus have on the spinothalamic tract?

Either excite or inhibit.
So increase or decrease pain

95

2 examples of opioids that play a role in descending inhibition of pain

Enddorphins
Enkephalins

96

What receptors do opioids act upon?

Inhibitory metabotropic receptors

97

Give 3 sites from which opioids are released from

PAG - midbrain
Raphe - medulla
Dorsal horn

98

Give 3 inflammation related chemical that can activate nociceptors

ATP
H+
Serotonin

99

What 2 substances are related to neurogenic inflammation?

Substance P
CGRP

100

What term is defined as a non-noxious stimuli producing a painful response?

Allodynia

101

What term is defined as a noxious stimuli producing an exaggerated pain response?

Hyperalgesia

102

With regard to pain hypersensitisation what will peripheral and central sensitisation result in?

Peripheral - primary hyperalgesia
central - allodynia

103

How do bradykinin and NGF influence peripheral nerves sensitisation?

reduce threshold of heat activated channels

104

What are the 6 components of the basal gangia?

Putamen
Globus Pallidus Internal
Globus Pallidis External
Caudate nucleus
Substantia Nigra
Subthalmaic nucleus

105

What makes up the striatum of the basal gangia?

Caudate nucleus
Putamen

106

Draw the direct pathway of basal ganglia 5

Cortex
Striatum
GPi
Thalamus
COrtex

107

Draw the indirect pathway 7

Cortex
Striatum
GPe
Subthamic nucleus
GPi
Thalamus
Cortex

108

Draw the hyperdirect pathway

Cortex
Subthalmic nucleus
GPi

109

What are the different types of dopamine receptor on medium spiney neurons in basal ganglia and what effect do they have on excitation?

D1 - ramp up excitation
D2 - dampen down excitation

110

On what pathways are D1 and D2 receptors founnd in the basal ganglia and what effect do they have upon excitation?

D1 - direct - ramp up
D2 indirect - damp down

111

Does the release of dopamine from substantia nigra inhibit or promote movement?

Promote

112

What neurotransmitter opposes the effects of dopamine upon the medium spiney neurons?

Ach

113

What condition is described as a A high amplitude flailing of the limbs on one side of the body?

Ballisimus

114

Where on the direct/indirect pathway is affecting in ballismus and what us the commonest cause

Subthalmic nucleus
Stroke

115

What makes tic disorders worse/better?

Anxeity and fatigue
Distraction and concentration

116

Possible causes of tic disorders

Post infectious
genetic

117

What condition is described as a Jerky, brief, irregular contractions that are not repetitive or
rhythmic, but appear to flow from one muscle to the next?

Chorea

118

Commonest causes of chorea?

Huntingtons
Neuropeltic drugs

119

The three areas impacted by Huntingtons

Cognitive - inability to plan
Behavioural - irritable, depression, anxiety
Motor - chorea

120

What disorder is Brief movement rapid onset and offset
Positive (muscular contractions) or negative (muscular inhibitions)

Myoclonus

121

£ common causes of myoclonus

Juvenile Myoclonic Epilepsy
Brain hypoxia
Prion disease

122

What condition is defined as abnormal twisting posture – often axial/ facial/ truncal, may be associated with jerky tremor

Dystonia

123

5 possible causes of dystonia

Stroke
Brain injury
Encephalitis
Huntington's
Parkinson's

124

3 types of treatment for hyperkinetic disorders

D2 blocking agents - haloperidol
Dopamine depleting agents - reserpine
Atypical antipsychotics - clozapine

125

3 Key side effects of dopamine blocking drugs

Oculogyric crisis - acute
Neuroleptic malignant syndrome
Drug induced Parkinsonism

126

3 features of neuroleptic malignant syndrome

Rigidity - raised CPK
Fever/Confusion
Autonomic instability

127

What condition involves lip smacking, tongue and cheek movements?

tardive dyskinesia

128

Treatment of tardive dyskinesia? 4

gradual withdrawal
substitute with atypical antipsychotic
dopamine depleting agent
use of benzodiazapine

129

Type of tremor that comes with Parkinson's?

Resting tremor

130

5 Non motor symptoms of Parkinson's?

Dementia
Depression
Postural hypotension
Sleep disturbance
Reduced sense of smell

131

4 non neurodegenerative causes of parkinson's?

Drugs - haloperidol
Cerebrovascular disease
Hydrocephalus
Toxicity

132

Two examples of Monoamine oxidase Inhibitors and what can they be used to treat?

Selegiline
Rasagiline
For parkinson's

133

Mechanism of action for lidocaine?

sodium channel blocker

134

How does Topical capsaicin treatment work for the treatment of acute pain?

TRPV1 agonist
Repeated use reduces nocicpetor firing
Peripheral terminals die back

135

How do NSAIDs reduce inflammation and therefore pain?

COX inhibited
Reduce prostaglandin synthesis
prevent's decrease in sodium channel threshold

136

What is the mechanism of action for opoids and 3 sites of action?

Agonists for endogenous opoid system
Brainstem
Spinal cord
Peripheral

137

These statements refer to what pain related theory?
Modulation of pain at the spinal cord level

Pain evoked by nociceptors can be reduced by simultaneous activation of low threshold mechanoreceptors (Aβ fibres)

Gate control theory

138

2 peripheral mechanisms of chronic pain?

1. Peripheral sensitization
2. Spontaneous firing of nociceptors

139

In chronic pain what causes the spontaneous firing of nociceptors following a nerve injury?

Accumulation of ion channels at regenerating tip of axon

140

What is the mechanism for central sensitisation on chronic pain?

Due to the reduced threshold for activation of 2nd order neurons

141

WHat are the 6 steps for reducing threshold for activation in chronic pain?

Constant firing of axons from the periphery (following injury) gives a Sustained release of glutamate
Prolonged depolarisation of the postsynaptic membrane
Massive influx of Ca2+ through NMDA receptors
Activation of kinases
Phosphorylation of NMDA/AMPA receptors
Channel protein synthesis

142

What is the mechanism for central hyperalgesia?

Activation of nociceptors results in amplified spinal cord activation

143

What is the mechanism for central allodynia?

Non-noxious Aβ fibres also synapse onto 2nd order spinothalamic neurons
Following central sensitization:

Non-noxious afferents activate sensitized 2nd order neurons

144

3 types of drugs that can treat chronic pain?

- Tricyclic antidepressants
- Anticonvulsants
- NMDA antagonists

145

AN example of tricyclic antidepressant>

Amitriptyline

146

Example of an anticonvulsant

carbamazepine

147

Example of an NMDA antagonist and mechanism of action?

ketamine
- NMDA receptor antagonist (reduces glutamate influx)
- Prevents depolarization of second order neuron