Final Flashcards
1
Q
Name the 6 parts of the CNS that are involved in complex movements
A
Cerebral Cortex Basal Ganglia Cerebellum Thalamus Brain stem Spinal Cord
2
Q
What kind of arrangement does the primary cortex have
A
Somatotopic
3
Q
What sections of the primary motor cortex is considered premotor
A
anterior and lateral portions
4
Q
Where does the premotor area of the primary motor cortex project to?
A
Primary order motor cortex and basal ganglia
5
Q
Does the primary motor cortex stimulate movements or contract single muscles?
A
Stimulate movements
6
Q
What part of the brain does the supplemental motor area lie in?
A
Mainly in longitudinal fissure
7
Q
What are the 4 functions of the supplemental motor area
A
attitudinal movements
fixation movements
positional movements of head and eyes
background for finer motor control of arms/hands
8
Q
What are the 3 areas the corticospinal tract originates
A
Primary motor cortex (30%)
Premotor and supplemental areas (30%)
Somatic sensory areas (40%)
9
Q
What spinal tract makes up the pyramids and medulla
A
cotricospinal tract
10
Q
Where do most corticospinal tract fibers run? Do they all run in same area
A
They cross midline and form the lateral corticospinal tract
No; some fibers stay ipsilateral and form ventral corticospinal tract
11
Q
True or false the corticospinal tract lies between the caudate and putamen
A
True
12
Q
If all the spinal tracts were cut and the spinal cord was completely separated from brain what would happen?
A
Flaccidity or “floppy paralysis”
13
Q
What would happen if spinal cord was cut at mid collicular level? (Decerebrate preparation)
A
Extensors would be tonically hyperactive “decerebrate rigidity”
14
Q
What would happen if there was destruction of the cerebral cortex (Decorticate preparation)
A
Different type of rigidity - “Decorticate spasticity” - tonic excitation from upper area of the reticular formation no longer under inhibitory cortical influence.
15
Q
What percentage of intracerebral hemorrhages result in decorticate spasticity?
A
60%
16
Q
What is decerebration? What does it result in?
A
Experimental procedure; transection of midbrain at intercollicular level
Loss of sensation; and motor control is profoundly altered
17
Q
In decerebration does the brain stem control stay intact? Are cortical descending pathways interrupted?
A
Yes it stays intact
yes they are interrupted
18
Q
In decerebration what happens to flexion reflexes? What about stretch reflexes?
A
Flexion reflexes are suppressed
Stretch reflexes are exaggerated
19
Q
If a patient showed signs of decerebration what would their prognosis be?
A
Poor
20
Q
What is “spinal shock”
A
Initial reaction to cord transection
All cord functions including spinal reflexes are depressed (lack of tonic excitation)
21
Q
At the onset of clockwise rotation (to the right), what would you expect happens in the VIII cranial nerve on the left side?
A
Decrease in firing rate
22
Q
After 20 clockwise (to the right) rotations with the eyes closed on a revolving stool, the subject is abruptly stopped, and the eyes are opened.
What is observed?
A
Lateral nystagmus with the slow component clockwise
23
Q
When supine, head tilt is best detected by what?
A
Saccule
24
Q
When standing, head tilt is best detected by what?
A
Utricle
25
True or false, signals from neck proprioceptors typically augment signals from the vestibular apparatus as the head and neck are rotated and have similar effects on limb flexion and extension. What would make this statement the opposite of the answer?
False
| Signals from neck proprioceptors would oppose not augment (assist)
26
In backward sway, what sequence of contraction of muscles to maintain balance would occur?
Tibialis, then quadriceps, then abdominals
27
In forward sway, what sequence of contraction of muscles to maintain balance would occur?
Gastrocnemius, then hamstrings, then paraspinals
28
What would happen to a repetitive simple stretch reflex, if when the muscle contracts it destabilizes posture?
it would be inhibited
29
What would happen to a repetitive simple stretch reflex, if when the muscle contracts it stabilizes posture?
It would be facilitated
30
```
Of the four pathways:
striatospinal
spinocerebellar
nigralstriatal
rubrospinal
```
Which pathway doesn't exist?
Striatospinal
31
Which basal ganglia circuit plays a major role in cognitive control of motor activity?
Caudate circuit
32
Which basal ganglia circuit plays a major role in subconscious control of motor activity?
Putamen circuit
33
True or false; one's sense of upright is generally a combination of cues that include both visual and vestibular information
True
34
What effect does the striatum have on the substantia nigra?
inhibitory GABA projections
35
What effect does the substantia nigra have on the striatum
inhibitory dopamine projections
36
Which area acts as a comparator, comparing intention with actual motor performance, and can effect the cerebellum via climbing fiber input?
Inferior olivary nucleus
37
Strong stimulation of one climbing fiber would elicit what response
complex action potential from a few purkinje cells
38
Strong stimulation of one mossy fiber would elicit what response?
simple action potential from many purkinje cells
39
Spontaneous and continuous writhing movements (athetosis) is associated with a lesion in what area?
globus pallidus
40
Hemibalistic movements are associated with a lesion in what area?
Subthalamus
41
A patient presents with a resting tremor, lead pipe rigidity in the extremities. Voluntary movements are accurate but slow. Where is a lesion likely to be found?
Basal ganglia
42
A patient presents with a intention tremor, where is a lesion likely to be found?
Cerebellum
43
A patient presents with ataxia, upon examination they are unable to perform rapid alternating movements, and unable to check movements (rebound) of the right arm. Where is a lesion likely to be found?
Right side of cerebellum (cerebellum always ipsilateral)
44
Is the pathway correct?
| Corticopontocerebellorubrothalamocorticospinal
yes
Remember: Correct Pathway Certainly Rough, This Could Suck
CorticoPontoCerebelloRubroThalamoCorticoSpinal
45
Is the pathway correct?
| Corticorubrocerebellopontothalamocorticospinal
No
46
The ventral spinocerebellar tract gains access to the cerebellum primarily via which peduncle?
Superior
47
The dorsal spinocerebellar tract gains access to the cerebellum primarily via which peduncle?
Inferior
48
If you administer yohimbine (an alpha 2 receptor blocker) and then stimulate the sympathetic nervous system, what effect do you expect on the amount of norepinephrine released?
Increased
49
True or false decreased rate of blood coagulation is associated with SNS (sympathetic nervous system)
False, increased rate of blood coagulation is
50
Denervation supersensitivity is likely associated with what?
Up regulation of receptors by the target tissue
51
What is the effect of the SNS stimulation on most vascular smooth muscle
constrict
52
Inhibitory motor neurons from the myenteric plexus release what neurotransmitters?
Dynorphin
| Vasoactive intestinal peptide
53
A patient presents with a slight ptosis of the left eye, but the right pupil appears dilated compared to the left, and they report that the let side of their face never sweats. What's your opinion doctor?
Interruption of the left sympathetic supply to the face
54
On EMG (electromyography), what is the clinical significance of an decreased number of motor units activated during a voluntary muslce contraction?
Possible neuropathy ("n" is less)
55
On EMG (electromyography), what is the clinical significance of an increased number of motor units activated during a voluntary muslce contraction?
Possible myopathy ("m" is more)
56
In primary cultures of postganglonic SNS neurons, what inhibits the release of norepinephrine?
GABA
57
If there is a facilitated spinal segment at T6. What would you expect when 3 kg of pressure is applied to the spinous process at T10 which is not in a state of segmental facilitation
Exaggerated response in adjacent paraspinal muscles at only T6
58
How much pressure can be applied to a normal vertebrae eliciting only a minimal response in the adjacent paraspinal muscles/
7 kg
59
True or false the CNS coordinates host defense activity
true
60
In a spinal cord transection how long does it take for spinal cord neurons to regain excitability. Will the reflexes be normal?
days to weeks
| some will be hyperactive
61
What happens in a spinal mass reflex?
Spinal cord becoming excessively active
| flexor spasm and evacuation of bladder and colon
62
What happens to blood pressure during spinal shock? What about skeletal muscle? Sacral reflexes?
Blood pressure falls dramatically
All skeletal muscle reflexes in cord are blocked
Sacral reflexes for bladder and colon evacuation control are suppressed
63
What tract transmits excitatory signals in the pontine reticular nuclei?
pontine (medial) reticulospinal tract
64
What does the pontine reticular nuclei stimulate?
axial trunk and extensor muscles that support body against gravity
65
Where does the pontine reticular nuclei receive stimulation from?
vestibular nuclei and deep nuclei of cerebellum
66
True or false, the pontine reticular nuclei has a low degree of natural excitability
False, it has a high degree
67
What tract transmits inhibitory signals in the medullary nuclei? And what muscles does it communicate with?
Medullary (lateral) reticulospinal tract
| and it inhibits the same anti-gravity muscles that the pontine reticular nuclei stimulates
68
Where does the medullary nuclei receive it's input?
cortex, red nucleus, and other motor pathways
69
What are 6 roles of the brain stem in controlling motor function?
```
Controls:
Respiration
cardiovascular system
GI function
stereotyped movements
equilibrium
eye movement
```
70
What are 3 very important ipsilateral descending tracts from brain to spinal cord?
Ventral corticospinal tract
Reticulospinal tract
Vestibulospinal tract
71
What tract are the pontine (medial) reticular formation and medullary (lateral) reticular formation a part of
Reticulospinal tracts
72
Where does the vestibulospinal tract get it's origin
lateral vestibular nucleus to extensors
73
Name 3 very important contralateral descending tracts from brain to spinal cord
Lateral corticospinal tract
Rubrospinal-innervate mainly flexors
Trecto-spinal-innervate cervical musculature only
74
What are the two lateral motor descending spinal tracts?
Lateral corticospinal and Rubrospinal
75
What does the rubrospinal tract mainly control?
distal muscles
76
What are the 4 medial motor descending spinal tracts, what do they mainly control?
Reticulospinal, vestibulospinal, tectospinal and ventral corticospinal
mainly axial and girdle muscles
77
Which corticospinal tract fibers form the lateral corticospinal tract
contralateral fibers
78
What percentage of corticospinal tract fibers originate from areas behind the central sulcus, including the primary somatosensory cortex
40%
79
Greater than 1/2 of the primary motor cortex is devoted to control of what?
hands and speech (homunculus)
80
A stroke that lesions the posterior limb of the internal capsule would be associated with what?
loss of voluntary movement
81
A lesion of high brain stem will result in what?
spasticity
82
A lesion of middle brain stem will result in what?
rigidity
83
A lesion of low brain stem will result in what?
flaccidity
84
Which brainstem area that receives stimulation from the vestibular nuclei and transmits excitatory signals to stimulate the axial trunk and extensor muscles that support the body against gravity/
Pontine reticular nuclei
85
What does dynamic signals from pyramidal cells cause?
Initiates contraction
86
What does static signal from pyramidal cells cause?
fire at a slower rate to maintain contraction
87
Signals for movement originate in the sensory association cortex and output to premotor cortex directly and indirectly via:
Basal ganglia and cerebrocerebellum
88
Excitatory motor neurons from the myenteric plexus (auerbach) releases what neurotransmitters?
ACH and Substance P
89
What would a normal muscle look like during activity on a EMG?
no spontaneous electrical activity except at end-plate regions (neuromuscular junctions)
90
What would an abnormal muscle look like during activity on a EMG?
Spontaneous activation of individual motor units, sharp waves (characteristic of neuropathic disorders like ALS)
91
What two kinds of movements are included when trying to maintain posture
Static reflexes (sustained contraction) and dynamic short term phasic (transient movements)
92
What happens to a muscle as muscle spindles lengthen?
muscle contracts
93
What are the 3 types of postural reflexes?
vestibular
tonic neck
and righting reflexes
94
What does your vestibular apparatus detect?
sensations of equilibrium
95
What part of your CNS that is involved in equilibrium contains sacules, utricles, and semicircular canals
Vestibular apparatus
96
What part of your CNS involved in postural reflexes is embedded in the petrous portion of temporal bone?
Vestibular apparatus
97
What is the macula? what is it covered in?
Sensory area of the vestibular apparatus (utricle and saccule)
covered in a gelatinous layer
98
How does the macula detect directional sensitivity?
Hair cells that project in macula project cilia into gelatinous layer
directional sensitive hair cells cause depolarization or hyper polarization
99
True or false, the utricle and saccule macula can detect linear velocity
False, it can detect linear acceleration though (when in car can tell when accelerating but cannot tell difference between 40 mph or 80 mph)
100
The macula of the utricle lies mainly in what plane?
horizontal plane
101
The macula of saccule lies mainly in what plane?
vertical plane
102
Semicircular canals of the vestibular apparatus contains what structure?
What is that made up of?
```
Crista ampularis (swelling/ampulla) Cupula
loose gelatinous tissue mass
```
103
When are the semicircular canals of the vestibular apparatus stimulated?
when head begins to rotate
104
How many pairs of semicircular canals are there? What are their names?
3
| anterior, horizontal and posterior
105
What are the semicircular canals filled with? What is that substance enriched with?
Endolymph which is enriched with potassium ions
106
As your head begins to rotate, what is happening in the semicircular canals
fluid lags behind and bends cupula
| This generates a receptor potential altering firing rate of CN VIII (projecting onto the vestibular nuclei)
107
What does CN VIII detect when receptor potentials are altered by fluid lagging in the semicircular canals
detects rotational acceleration and deceleration
108
What does stimulation of your semicircular canals do to your extensors? What about your eyes?
```
Causes increased extensor tone
Causes nystagmus (slow tracking component)
```
109
The vestibular nuclei which receives information from CN VIII and the semicircular canals makes connections with what other cranial nerves and brain structure?
CN associated with ocular movements (III, IV, VI) and cerebellum
This is what can stimulate Nystagmus (drunk eyes)
110
What can initiate the slow component nystagmus (tracking)
semicircular canals
111
What can initiate the fast component nystagmus (jump ahead to new focal spot)
brain stem nuclei
112
What other brain structure does the semicircular canals work closely with to make anticipatory corrections to for equilibrium
the cerebellum (specifically the flocculonodular lobe)
113
Where does proprioceptive information from the neck project onto?
the vestibular nucleus and cerebellum
114
True or false cervical joint proprioceptors can override signals from vestibular apparatus to prevent the feeling of dis-equilibrium
true
115
What is the most common cause of vertigo? What causes it?
Benign paroxysmal positional vertigo
| Sudden sensation of spinning, usually when moving head
116
What would you do for a patient who presented with benign paroxysmal positional vertigo? What is the success rate of this maneuver?
"Epley's maneuver"
This causes any free floating particles in semicircular canal to relocated (via gravity) and therefore can no longer stimulate cupula relieving vertigo
90 to 95%
117
True or false, one's sense of upright is only derived from vestibular information?
False
it is generally a combination of visual cues and vestibular information
(tilting room and chair example from class)
118
What evokes vestibular reflexes?
changes in head position
119
What triggers neck reflexes?
tilting or turning of the neck
120
What are the two major mechanisms of postural adjustments?
anticipatory (feed forward) - predicts disturbance
| Compensatory (feedback)
121
How does your body build anticipatory (feed forward) postural adjustments?
modified by experience; improves with practice
122
What evokes compensatory (feedback) postural adjustments
sensory events following loss of balance
123
What would be an example of a extremely rapid postural adjustment?
simple stretch reflex
124
Would proprioceptive information from your joints and muscles be considered short latency or longer latency information in regards to postural mechanisms
Short latency (~70-100 ms)
125
What would be an example of longer latency in regards to information in your postural mechanisms
Vestibular or Visual signals (twice as long as proprioceptive information)
126
True or false, receptors in your skin are not involved in postural adjustments?
False, very high in your feet
127
Does extension of your neck reflexes facilitate or inhibit extensors of your arms and legs
facilitates
128
Does flexion of your neck reflexes facilitate or inhibit flexors of your arms and legs?
facilitates
129
How will rotation or lateral bending of your neck reflexes affect your extensors and flexors
It will facilitate extensors on ipsilateral side
| It will facilitate flexors on contralateral side
130
What are the 4 principle nuclei of the basal ganglia
striatum (caudate and putamen)
globus pallidus
substantia nigra
subthalmic nucleus
131
What are the 3 input nuclei of basal ganglia
Caudate
Putamen (together striatum)
Nucleus accumbens
132
What are the 4 output nuclei of basal ganglia
Globus pallidus (external segment)
subthalamic nucleus
substantia nigra
ventral segmental area
133
True or false, basal ganglia has direct input/output with spinal cord
False, it does not have direct input/output
134
Disorders of the basal ganglia have 3 characteristic types; what are they?
tremor and other involuntary movements
changes in posture and muscle tone
poverty and slowness of movement
135
What is athetosis? What causes it?
spontaneous and continuous writhing movements
| lesion in globus pallidus
136
What is hemiballismus? What causes it?
sudden violent flailing movements of limbs
| lesion of sub thalamus
137
What is chorea? What causes it?
flicking movements in hands, face ("dance" from CNS)
| multiple small lesions of putamen
138
Rigidity, akinesia, resting tremors (parkinson's) are all associated with issues of what area?
Substantia nigra
139
What % of the brain's mass comes from the cerebellum?
10%
140
True or false, the cerebellum contains greater than half of the brains neurons
True
141
True or false, complete destruction of the cerebellum would produce severe impairment on sensory processes, and result in loss of muscle strength
False, it wouldn't effect either of those
142
What does the vestibulocerebellum govern? What is its input/output nuclei? What is another name for it?
Governs eye movement and body equilibrium
Vestibular nuclei (input and output)
Floculonodular lobe
143
What does the spinocerebellum play a major role in? What is its input/output? What is another name for it?
Major role in movement, influencing descending motor systems
Input: periphery and spinal cord
Output: cortex
Vermis and intermediate lobes
144
What does the cerebrocerebellum control? (3 things)
Planning and initiation of movement and extra motor prediction
Mental rehearsal of complex motor actions
conscious assessment of movement errors
145
What is the input/output of the cerebrocerebeullum? What is another name for it?
Input: pontine nucleus
output: pre and motor cortex
Lateral zone
146
What is the major inhibitory cell of the cerebellar cortex? (inhibits and projects to the deep cerebellar nuclei)
purkinje cells
147
How do complex action potentials differ from simple action potentials from purkinje cells? (hint: what fibers do each travel in, ratio of fiber to purkinje?)
Complex AP: from climbing fibers via inferior olivary nucleus (1:1 ratio of climbing fibers to purkinje)
Simple AP: from mossy fibers via granule cells (1 mossy fiber excites hundreds-thousands of purkinje cells)
Mossy fibers come from everywhere EXCEPT inferior olivary nucleus
148
A patient with lesions of the cerebellum would present with symptoms on which side of the body compared to the lesion?
Ipsilateral
149
True or false the cerebellum is loaded by the integrity of joint mechanoreceptors
True
150
Name the 3 deep nuclei of the cerebellum
Fastigial
Interposed (globose and emboliform)
Dentate
151
Does the superior peduncle of the brain stem project afferent or efferent fibers or both?
Both afferent and efferent
152
Does the middle peduncle of the brain stem project afferent or efferent fibers or both?
Efferent only
153
Does the inferior peduncle of the brain stem project afferent or efferent fibers or both?
Afferent
154
True or false, the cerebellum receives info about plans for movement from brain structures concerned with programming and executing movement? If so, what is this called?
True
| corollary discharge/internal feedback
155
True or false, the cerebellum receives info about motor performance from peripheral feedback while you're moving. If so, what is this called?
True
| reafference/external feedback
156
Who proposed the idea of homeostasis?
Walter Cannon in 1932
157
During the same time Walter Cannon proposed the idea of homeostasis, what other idea did Cannon introduce?
negative feedback regulation
158
What are the 3 major divisions of the autonomic nervous system (ANS)
Sympathetic (Fight or Flight)
Parasympathetic (Rest and Digest)
Enteric (GI tract)
159
Smooth muscle, heart muscle, and exocrine glands are all controlled by what system?
Autonomic Nervous System (ANS)
160
Pre-ganglionic sympathetic cells release mainly what neurotransmitter?
acetylcholine (ACH)
| sometimes releases neuropeptides (LHRH)
161
Post-ganglionic sympathetic cells release mainly what neurotransmitter?
norepinephrine
| sometimes releases neuropeptides (NPY)
162
Pre-ganglionic sympathetic cells reside in the lateral horn at what spinal nerve levels?
C8-L2 or L3
163
Paravertebral and Prevertebral ganglia are associated with what kind of ganglionic cells?
Post-ganglionic sympathetic cells
164
True or false, post-ganglionic sympathetic cells that release norepinephrine can regulate them selves? (negative feedback) If so, what makes this possible?
true
| the presence of alpha 2 receptors allows norepinephrine to bind to the receptors and regulate itself
165
What substance can block alpha 2 receptors that would regulate the breakdown of norepinephrine? What would the presence of this substance do to the amount of norepinephrine released?
Yohimbine
| It would increase
166
How many impulses a second are there in a normal sympathetic tone?
1/2 to 2 impulses a second
167
What is sympathocotonia?
Increased sympathetic activity (hyperactivity)
168
What is Horner's syndrome? what are 4 symptoms?
```
Interruption of sympathetic supply to head
Partial ptosis (drooping eyelid)
Pupillary constriction
Anhydosis (in ability to sweat)
Enophthalmos (retraction of eyeball into socket due to lack of innervation to smooth muscles of eye)
```
169
Edinger-Westphal nucleus is a part of what parasympathetic CN
III
170
The superior salivatory nucleus is a part of what parasympathetic CN
VII
171
The inferior salivatory nucleus is a part of what parasympathetic CN
IX
172
The dorsal motor, and nucleus ambiguus is a part of what parasympathetic CN
X
173
What does the nucleus ambiguus do?
bradycardia or slows heart rate
174
The ciliary, pterygopalaine, submandibular, and otic ganglia are all post-ganglionic or pre-ganglionic parasympathetic ganglia?
Post-ganglionic parasympathetic
175
Which parasympathetic CN innervates the heart, lungs, bronchi, liver, pancreas, and almost all of the GI tract?
X the Vagus nerve
176
What affect does Norepinephrine have on intestinal motility and sphincters?
Slows/Contracts
177
Norepinephrine and Somatostatin have what effect on intestinal secretion?
inhibit
178
Pre-ganglioninc parasympathetic stimulation of the GI tract will cause what?
increase motility and tone
relax sphincters
stimulate secretion
(remember Parasympathetic = Rest and Digest)
179
The myenteric plexus (Auerbach) controls peristalsis by releasing what hormones?
```
Excitatory = ACH and Sub P
Inhibitory = Dynorphin and vasoactive intestinal peptide (VIP)
```
180
What excitatory neurotransmitter do visceral afferent fibers release?
Glutamate
| Can also release neuropeptides (VIP, Sub P, Somatostatin, CCK, etc.)
181
True or false, release of norepinephrine can increase membrane permeability
True
| It effects G proteins ----> releasing cAMP ---> increases protein kinases -----> increasing permeability
182
Sympathetic effect on eyes
dilate pupils
183
Sympathetic effect on glands
increases concentrate secretion because decreases blood flow to area
Causes sweat glands to stimulate
184
Sympathetic effect on GI
inhibit
185
Sympathetic effect on heart
stimulate
186
Sympathetic effect on blood vessels
constrict
187
Parasympathetic effect on eyes
constrict pupil, ciliary muscles, and increase lens strength
188
Parasympathetic effect on glands
stimulated
189
Parasympathetic effect on GI tract
stimulated
190
Parasympathetic effect on heart
inhibit
191
Parasympathetic effect on blood vessels
largely absent
192
Parasympathetic effect on airways
constrict
193
Parasympathetic effect on ducts
constriction
194
Parasympathetic effect on immune
unknown
195
Sympathetic effect on airway
dilation
196
Sympathetic effect on ducts
dilation
197
Sympathetic effect on immune
inhibits
198
Tyrosine is the precursor for what?
Dopamine, norepinephrine and epinephrine
199
Nicotinic and muscarinic are both receptors for what neurotransmitter?
ACH
