lecture 10: motor systems Flashcards
1
Q
true or false: motor pathways are usually 3 neurons
A
false, 2
2
Q
where are the upper motor neuron cell bodies located
A
in cortex (or brainstem)
3
Q
where are the lower motor neuron cell bodies located
A
in ventral horn or brainstem
4
Q
UMN are CNS or PNS
A
CNS
5
Q
LMN are CNS or PNS
A
PNS
6
Q
upper motor neuron axons comprise tracts or nerves
A
tracts (central nervous system)
7
Q
lower motor neuron axons comprise tracts or nerves
A
nerves (peripheral n system)
8
Q
LMN innervate what
A
muscles
9
Q
the motor pathways are broadly divided in what 2 systems
A
1) lateral motor system
2) medial motor system
10
Q
the lateral motor system contains what info
A
control of appendicular muscles
11
Q
control of appendicular muscles is laterlal or medial system
A
lateral
12
Q
the medial motor system controls what
A
control of axial muscles (eg: postural tone)
13
Q
control of axial muscles (eg: postural tone) is lateral or medial motor system
A
medial
14
Q
what are the 3 divisions of the lateral motor system
A
lateral corticospinal
lateral reticulospinal
rubrospinal
15
Q
what are the 4 divisions of the medial motor system
A
medial reticulospinal
anterior corticospinal
vestibulospinal
tectospinal
16
Q
what pathway contains our volunteary pathway to move
A
lateral corticospinal
17
Q
be able to locate the pathways on the crossection of the SCq
A
18
Q
what are the pyramidal pathways
(2)
A
corticospinal and corticonuclear
19
Q
what category of pathway is control of musculature or trunk and limbs
A
(lateral and ) corticospinal
20
Q
:)
what pathway is equivalent to corticospinal pathway but for synapses in the brainstem
A
corticonuclear
21
Q
corticonuclear pathways synapse where
A
in the brain stem
22
Q
what does the corticonuclear pathway control
A
musculature of the head and neck
23
Q
musculature of the head and neck is associated with what pathway
A
corticonuclear
24
Q
extrapyramidal pathways original where
A
in brainstem
25
extrapyramidal pathways originate in brainstem but receive cortical input via what and what is their purpose
corticofugal fibers
fibers that project from the cerebral cortex to nuclear masses in the brainstem and spinal cord (go to extrapyramidal)
26
what are the extrapyramidal pahthways
rubrospinal
tectospinal
reticulospinal
vestibulospinal
27
UMN cell bodies are located in what cortical motor area
Most in primary
(some in premotor and supplementary)
28
what is the function for cortical input from premotor and supplementary cortical
=supplemental
aids with planning of complex movement
29
rubrospinal pathway originates in what part of brainstem
red nucleus
30
tectospinal pathway originates in what part of brainstem
superior colliculi
31
reticulospinal pathway originates in what part of brainstem
reticular formation
32
vestibulospinal pathway originates in what part of brainstem
vestibular nuclei
33
all of the motor pathways synapse where (first synapse)
in anterior horn or brainstem
34
all of the motor pathways synapse where (second synapse)
axons will synapse with target tissue (skeletal muscle)
35
50% of the UMN are located where
in the primary motor cortex
36
if 50% of UMN are located in the primary motor cortex, where are the others located
premotor cortex
supplementary cortex
37
true or false, in the motor pathways primary motor cortex is somatotopically organized and explain
true
UMN synapse with LMN at different levels depending on where the UMN cell is located
38
are motor neurons pseudo unipolar or multipolar
multipolar
39
true or false: upper motor neurons axons pass thru the posterior limb of internal capsule
true
40
upper motor neuron axons form the BLANK of the internal capsule
the posterior limb
41
corticospinal fibers carry info for what region
trunk and limbs
42
corticonuclear fibers carry info for what region
head and neck
43
explain the somatotropin arrangement of the internal capsule
corticonuclear fibers (F:face) form the genu of the internal capsule
cortispinal fibers are arranged from rostral (C:cervical) to caudal (L:lumbosacral)
44
corticonuclear fibers from what aspect of the internal capsule
genu
45
corticosinal fibers from what aspect of the internal capsule
arranged from from rostral (C:cervical) to caudal (L:lumbosacral)
46
what is the anterior limb of the internal capsule comprised of
motor and sensory fibers
47
what is the motor aspect of the anterior limb
motor tracts include the corticofugal fibers
=cortical regulation of extrapyramidal pathways
48
motor tracts include the corticofugal fibers in anterior limb, what is their purpose
=cortical regulation of extrapyramidal pathways
49
explain location of UMN of corticospinal pathways axons in midbrain
UMN of corticospinal pathways in cerebral peduncles
50
UMN of corticospinal pathways in cerebral peduncles is in what aspect of the brainstem
midbrain
51
UMN of corticospinal pathways in cerebral peduncles, is that more ventral or dorsal
ventral
52
true or false, in the brainstem, motor pathways are located dorsal
false, ventral
53
UMN from corticospinal pathway cervical region are more lateral or medial in brainstem
medial
54
UMN in corticospinal pathway from lumbar region are more lateral or medial in brainstem
lateral
55
explain location of UMN corticospinal pathway axons in pons
UMN axons of cortispinal pathways in basilar (ventral) region of pons
56
explain the location of UMN of corticospinal pathway in rostral medulla
UMN axons of corticospional pathways in medullary pyramids
57
after entering the brainstem, the tracts formed by the UMN axons in the corticospinal pathway are found what region of the brainstem
ventral
58
true or false, somatotropin organization of motor patwhways is similar throughput and explain
true
cervical more medial
lumbar more lateral
59
be able to understand the location of corticospinal pathway in brainstem and the associated blood vessels
60
what blood vessel supplies the corticospinal UMNs in the midbrain
posterior cerebral
61
what blood vessel supplies the corticospinal UMNs in the pons
basilar artery
62
what blood vessel supplies the corticospinal UMNs in the rostral medulla
anterior spinal a
63
if there was a lesion of the anterior spinal artery in the rostral medulla, would only the medial lemnisuc be affected?
no , also the corticospinal tract
64
decussation in the corticospinal pathway happens in what part of the brainstem
happens at the most caudal end of the brainstem
65
true or false: decussation in the corticospinal pathway happens at the most rostral end of the brainstem
false, caudal
66
90% of UMN in the corticospinal pathways decussate where
at the decussation of the pyramids (in the caudal medulla)
67
do all UMN of the CS pathway decussate at the decussation of the pyramids
no , 90% do and the other UMN continue ipsilaterally
68
decussation of the pyramids occurs at the BLANK end of the medulla
caudal
69
decussation of the pyramids occurs at the caudal end of the medulla .... aka what junction
spinomedullary junction
70
the UMN of the CS pathway that decussate form what tract in the spinal cord
the lateral corticospinal tract
71
true or false: the UMN of the CS pathway that decussate form the anterior corticospinal tract in the spinal cord
false, the lateral corticospinal
72
UMN of the lateral corticospinal tract stay ipsilateral, or go contra lateral
contralateral
73
10% of UMN of the CS pathway go contralateral or remain ipsi
remain ipsilateral
74
the 10% of UMN of the CS pathway that remain ipsilateral form what tract in the SC
form the anterior corticospinal tract
75
axons of UMN in the lateral corticospinal tract go where in the spinal cord
lateral spinal column
76
axons of UMN in the anterior corticospinal tract go where in the spinal cord
anterior spinal column
77
in the dorsal column, what general pathway goes there
DCML (only sensory)
78
in the lateral column, what general pathways go there
spinocerebellar
lateral corticospinal
(Motor and cerebellum)
79
in the anterior column, what general pathways go there
anterior cortcispinal
spinothalamaic
(motor and sensory)
80
axons of UMN in lateral CS tract control what
appendicular muscles (voluntary, skilled movements)
81
axons of UMN in anterior CS tract control what
control of axial muscles
(postural tone and balance)
82
upper motor neurons of corticospinal pathway synapse with LMN where
in ventral / anterior horns
83
true of false, UMN of corticospinal pathway synapse with LMN in posterior/dorsal horn of SC
false, anterior
84
the lateral corticospinal tract synapses ipsilateral or bilateral in anterior horn
ipsilateral
85
the anterior corticospinal tract synapses ipsilateral or bilateral in anterior horn
bilateral
(has both ipsilateral and contralateral)
86
true or false, the anterior corticospinal tract UMN has bilateral projections
true
87
since the UMN of anterior corticospinal tract provide bilateral projections, explain how that would be implicated for lesion symptoms
symptoms are less visible/apparent because we have two tracts provided bilateral
=deficits will be minor
88
UMN for upper limb synapse at what spinal levels
c5-ti
89
UMN for lower limb synapse at what spinal levels
T2-L2
90
explain the general pathway steps of the lateral corticospinal tract
1) UMN in primary motor cortex (pre central gyrus)
2) corona radiate
3) internal capsule (posterior limb)
4) cerebral peduncle
5) pyramid (decussation of the pyramids)
6) lateral corticospinal tract)
7) synapse with LMN in ipsilateral ventral horn
8) spinal nerve goes to target tissue (skeletal m)
91
where is there primary motor cortex locatiedh
pre central gyrus (frontal lobe)
92
how does UMN get from brain to brainstem
cerebral peduncles
93
what is the pathway fir the anterior corticospinal pathway
1) UMN in primary motor cortex (pre central gyrus)
2) corona radiate
3) internal capsule (posterior limb)
4) cerebral peduncle
5) pyramid ((NO DECUSSATION)
6) ANTERIOR corticospinal tract)
7) synapse with LMN in ventral horn (ipsilateral and contralateral)
8) spinal nerve goes to target tissue (axial muscles)
94
true or false: uMN lesions are always ipsilateral
false, LMN are
95
UMN lesions can be contralateral or ipsilateral reparative to the lesion depending on what
on level of the lesion
96
symptoms for UMN are always below the level or the lesion
or always at and below
always below the level of the lesion
97
if an UMN lesion is above decussation, will the symptoms be ipsilateral or contralateral
contralateral
98
if an UMN lesion is below decussation, will the symptoms be ipsilateral or contralateraleral
ipsilateral
99
if you have both LMN symptom and UMN at the same level,, which wins
LMN
100
what are the 3 general symptoms with an UMN
paresis/paralysis (no cortical input (UMN) to LMN)
spasticity, hyperrefflexia, altered tone
(LMN not regulated by UMN)
possible positive babinski sign
101
explain why in UMN lesion you may see paralysis or paresis
paresis/paralysis (no cortical input (UMN) to LMN)
102
explain why in UMN lesion you may see spasticity, hyper reflex, altered tone
(LMN not regulated by UMN)
103
true or false, you can get hyporeflexia with an UMN
false, hypperreflexta
104
explain the babinski sign
pathological reflex
when you swipe upwards on the foot base, the toes spread upwards
=normal in kids only
105
in a LMN lesion, will the symptoms be contralateral, ipsilateral or both relative to the lesion
ipsilateral
106
for LMN lesions, are the symptoms at or below the level of the lesion
at and below
107
in LMN, the dysfunction is isolated to what
to myotomes associated with the damaged levels
108
what are the general categories of symptoms for LMN
paresis, paralysis, hypo or areflexia
(loss of motor input to muscles via LMN)
muscle wasting/atrophy
(long term result of chronic muscle denervation)
fasciculations
(spontaneous firing of LMN and increased receptor concentration.sensitivty)
109
explain why you might see paresis, paralysis, hypo or areflex in LMN lesion
loss of motor input to muscles via LMN)
110
explain why you might see muscle wasting/atrophy in LMN lesion
(long term result of chronic muscle denervation)
111
explain concept of fascinations for LMN lesions
if there are some motor neurons that have not been completely severed by a lesion they may become more sensitive to activation via the expression of more receptors and therefore are prone to spontaneouss firing
112
what is the patellar refelx
l3-l4
113
what is the calcanea reflex
s1-s2
114
what is the biceps reflex
c5-c6
115
what is the tricep reflect
c7-c8
116
if you have a LMN lesion at c8, will tricep show areflexia or hyporeflexia
hyporeflexia (c7 still in tact)
117
in the extrapyramadial tracts the UMN cell bodies are located where
in brainstem nuclei
118
are the extrapyramidal tracts responsible for concious or non conous function
non concious
119
the cell body in the rubrospinal tract is located where (specific)
red nucleus
120
the cell body in the tectospinal tract is located where (specific)
superior colliculi
121
the cell body in the reticulospinal tract is located where (specific)
reticular formation
122
the cell body in the vestibulospinal tract is located where (specific)
vestibular nuclei
123
rubrospinal tract faciliates flexors or extension
flexors
124
when do UMN decussate in rubrospinal
decussate immediately to contralateral side
125
true or false; rubrospinal is an archaic motor system
true
126
what is the function of the tectospinal tract
reflexible movement related to auditory/visual stimuli
127
when do UMN decussate in tectospinal
UMNs decussate immediately
128
what is function of the reticulospinal tract
maintains posture/balance and refines movement
129
the pontine fibers of the ritculospinal tract control what
extensors
130
the medullary fibers of the ritculospinal tract control what
flexors
131
do all UMN decussate in the reticulospinal tract
no . some UMN decussate and others stay ipsilateral
132
what is the function of the vestibulospinal tract
controls antigravity extensor muscles to help maintain balance and posture
=stabilizes head
133
do UMN of vestibulospinal tract go contralateral or stay ipsi
stay ipsilateral
134
true or false: it is easy to park out damage to individual extrapyramidal tracts
false
135
decerebrate signs are associated with what tract
rubrospinal tract
136
red nuclei is in rostral or caudal midbrain
rostral
137
if you see decerebrate posturing, is that extensor or flexor posturing
extensor
138
if you see decorticate posturing, is that extensor or flexor posturing
flexor
139
if you see decerebrate posturing, are the rubrospinal tracts damaged or intact
damaged
140
if you see decorticate posturing, are the rubrospinal tracts damaged or intact
intact
141
decerebrate rigidity is characterized by what
exaggerated extensor posturing (with flexed wrists)
142
what is the most common type of disc herniation
subarticular
143
explain subarticular herniation
When the disc extrudes between the spinal cord and the foramen
144
what is the second most common type of disc herniation
foramina or extraformainal
145
what is foraminal herniation
beneath and lateral to the vertebral facet,
146
what is the most uncommon disc herniation
central
147
what is central disc herniation
annulus fibrosus is damaged enabling the nucleus pulposus (which is normally located within the center of the disc) to herniate
148
what is a common cause of lower back pain
herniation of the nucleus pulpous of the intervertebrall disc into or tjru the annulus fibrosis
149
explain whyherniation of the nucleus pulpous of the intervertebrall disc into or tjru the annulus fibrosis is a common source of back pain
impingement of spinal cord, rootlets, roots, spinal nerves
150
true or false: herniated discs are always symptomatic
false, often incidental findings
151
central herniation of the intervertebral disc between L4 and L5 causes what
spares L4 nerves and compresses L5-Co nerves
=cauda equina syndrome
152
