Exam 2: Motor cortex Flashcards
(156 cards)
1
Q
Primary motor cortex
A
BM4
2
Q
Signals pyramidal cells of BM4 can produce
A
- Dynamic signal
- excessively excited to initiate muscle contraction - Static signal
- slower rate to maintain contraction
3
Q
Premotor area
A
BM6
4
Q
Premotor area projects to primary motor cortex and
A
Basal ganglia
5
Q
Supplemental motor area lies in
A
Longitudinal fissure
6
Q
Functions of supplemental motor area
A
- Attitudinal movements
- Fixation movements
- Positional movements of head and eyes
- Background for finer motor control of arms/hands
7
Q
Majority of fibers in corticospinal tract originate
A
In front of central sulcus
8
Q
Corticospinal tract descends between
A
Caudate and putamen
9
Q
Most corticospinal fibers cross midline and form
A
Lateral corticospinal tract
10
Q
Spinal preparation
A
Flaccidity
- lack of tonic excitation from higher centers
11
Q
Spinal preparation
Mass reflex
A
Spinal cord becomes excessively active
Flexor spasm
12
Q
Decerebrate preparation - motor control is altered, leading to
A
Rigidity
13
Q
Decerebrate preparation
____ reflexes suppressed, ____ reflexes exaggerated
A
Flexion
Extension
14
Q
Decorticate preparation is destruction of
A
Cerebral cortex
15
Q
Decorticate preparation results in ____ due to tonic excitation to extensors
A
Spasticity
16
Q
60% of intracerebral hemorrhages result in
A
Decorticate preparation
17
Q
Medial RST ipsilateral from
A
Pons
18
Q
Lateral RST mostly ipsilateral from
A
Medulla
19
Q
Functions of upward projections of reticular formation
A
Attention
Sleep
Arousal
20
Q
Functions of downward projections of reticular formation
A
Visceral and vegetative activity
-HR, breathing
Motor control
- timing of saccades
21
Q
Injury to reticular formation can cause
A
Reduced conscious state
Cushing reflex
Abnormal respiration patterns
-“ondine’s curse”
22
Q
____ receives projections form nearly every level of motor system
A
Reticular formation
23
Q
Pontine reticular nuclei stimulate axial trunk and
A
Extensors
24
Q
Pontine reticular nuclei receive stimulation form
A
Vestibular nuclei and deep nuclei
25
Pontine reticular nuclei send _____ via pontine reticulospinal tract
Excitatory signals
26
Medullary reticular nuclei send ____ to same extensor Muscles
Inhibitory signals
27
Medullary reticular nuclei receive input from
Red nucleus
28
6 descending pathways from brain to spinal cord
Ipsilateral:
1. Ventral corticospinal tract
2. Reticulospinal tract
3. Vestibulospinal tract
Contralateral
1. Rubrospinal tract
2. Tectospinal tract
3. Lateral corticospinal tract
29
Reticulospinal tract divisions
1. Pontine reticular formation
- medial, extension
2. Medullary reticular formation
- lateral, flexion
30
Tectospinal tract originates in
Medial portion
31
Lateral corticospinal tract innervates
Distal musculature
32
Rubrospinal tract innervates
Distal Muscles of limbs
| Flexors
33
Components of medial motor system
Tectospinal
Reticulospinal
Vestibulospinal
Anterior corticospinal
34
Planning and program phase of voluntary movement occurs in
Associated cortex
35
Execution phase of voluntary movement occurs in
Premotor cortex —primary motor cortex—spinal cord—spinocerebellum
36
3 components of voluntary movement
1. Grasping
- BM4
2. Reaching
- cerebellum, colliculus
3. Decide
- frontal cortex, basal ganglia
37
3 types of postural reflexes
1. Vestibular reflexes
2. Tonic neck reflexes
3. Righting reflexes
38
Vestibular apparatus is embedded in
Temporal bone
39
Vestibular apparatus detects
Sensations of equilibrium
40
Macula detects
Linear acceleration
41
Cupula of semicircular canals are stimulated as head
Begins to rotate
42
Semicircular canals are filled with
Endolymph
43
Semicircular canals detect rotational ___ and ___ on side rotation is on
Acceleration and deceleration
44
Semicircular canals have a ___ Function due to anticipatory corrections
Predictive
45
Semiciruclar canals work with ___ lobe
Flocculonodular
46
Slow component of nystagmus initiated by semicircular canals, ____ direction of perceived rotation
Opposite
47
Fast component of nystagmus initiated by brain stem nucleus, ____ direction of perceived rotation
With
48
Macula of utricle lies mainly in
Horizontal plane
49
Utricle determine orientation when
Upright
50
Macula of Saccule lies mainly in
Vertical plane
51
Saccule determines orientation when
Lying down
52
Cervical joints can override signals from ___ to prevent feeling of mal equilibrium when head tilted
Vestibular apparatus
53
Benign paroxysmal positional vertigo can be treated with
Epley’s maneuver
54
Ones’ sense of upright is generally a combo of cues that include
Visual and vestibular info
55
Major mechanisms of postural adjustments
Anticipatory
| Compensatory
56
Anticipatory mechanism is ____ and improves with _____
Feedforward
Practice / experience
57
Compensator mechanism is for
Sensory events
58
Forward sway muscles
Gastrocnemius
Hamstrings
Paraspinals
59
Backward sway muscles
Tibialis
Quads
Abs
60
Extension of neck =
Limb extensors
61
Flexion of neck =
Limb flexors
62
Caudate nuclei is involved in
Cognitive control of motor activity
63
Putamen nuclei in involved in
Subconscious execution of learned patterns of movement
64
Athetosis
Lesions in globus pallidus
65
Hemiballismus
Lesion in subthalamus
66
Huntington’s Chorea
Severe degeneration of caudate
Choreiform movements
67
Rigidity, resting tremor
Substantia nigra (Parkinson’s)
68
Cerebellum is ____ total brain by weight
10%
69
Destruction of cerebellum would result in disruption in eye and limb coordination, decreased ____ but no sensory impairment or loss in ____
Muscle tone
Muscle strength
70
Lesions in the cerebellum create ____ findings
Ipsilateral
71
Cerebellum has ____ descending direct connections with spinal cord
NONE
72
Cerebellum plays crucial indirect role in movement and posture by adjusting output of
Major descending motor systems
73
Functional divisions of cerebellum
Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum
74
Vestibulocerebellum aka
Floculonodular lobe
75
Vestibulocerebellum important for
Eye movement
| Body equilibrium
76
Spinocerebellum important for
Movement
77
Cerebrocerebellum important in
Planning and initiation of movement and extramotor prediction
78
Purkinje cells release
GABA
79
Purkinje cells generate 2 output signals
1. Complex AP
| 2. Simple AP
80
Complex AP
Climbing fiber input form inferior olivary n
1:1 ratio
81
Climbing fibers release
Aspartate
82
Simple AP
Mossy fibers input via granule cell
1 mossy: hundreds purkinje
83
Deep nuclei of cerebellum
Dentate
Emboliform
Globose
Fastigial
84
Role of inferior olivary nucleus
Effects cerebellum via climbing fiber input
85
3 things ANS controls
Smooth muscle
Cardiac muscle
Exocrine glands
86
Major divisions of ANS
1. Sympathetic
2. Parasympathetic
3. Enteric
87
SNS aka
Arousal
Fight or flight
88
SNS has ___ preganglionic cells that release ____
Short
ACH
89
SNS has ___ postganglionic Cells that release ___
Long
NE
90
Yohimbine
Alpha2 blocker
Increase NE release
91
SNS decreases
Blood flow to inactive organs/ tissues
92
SNS increases
```
Arterial pressure
Rate of cellular metabolism
Blood glucose metabolism
Glycolysis in liver and muscle
Muscle strength
Mental activity
Rate of blood coagulation
```
93
PSNS aka
Conservation
Rest and digest
94
PSNS has __ preganglionic cells that release ___
Long
ACH
95
PSNS has ___ postganglionic Cells that release
Short
ACH
96
NE binds to
Alpha or beta receptors
97
Sympathocotonia
Hyperactivity of SNS
98
Adrenal medulla is an
Extension of SNS
99
Adrenal medulla releases ___ and ___ via chromaphin cells
Epinephrine (80%)
Norepinephrine (20%)
100
Horner’s Syndrome symptoms
Partial ptosis (eyelid drooping)
Pupillary constriction
Anhydrosis
Enophthamas
101
Edinger-Westphal location
CN III
102
Superior salivatory nucleus location
CN VII
103
Inferior salivatory nucleus location
CN IX
104
Dorsal motor location
X
105
Nucleus ambiguus location
CN X
106
Postganglionic PSNS ganglia located in walls of
Visceral organs
107
Vagus nerve innervates ___ of PSNS organs
75%
108
Remainder of colon and rectum innervated by
Sacral preganglionic nerves
109
Vagus innervates up until
Splenic flexors of colon
110
ACH binds to
Muscarinic receptors
| Nicotinic receptors
111
Enteric NS located in
Walls of GI tract
112
NE affect on enteric NS
Inhibited intestinal motility
Regulates blood blow
Inhibit intestinal secretion
113
NPY effect on Enteric NS
Regulate blood flow
114
Somatostatin effect on enteric NS
Inhibit intestinal secretion
115
Preganglionci PSNS effect on enteric
Increase motility
Relax sphincters
Stimulate secretion
116
Myenteric plexus controls
Gut motility and coordinates peristalsis
117
Excitatory neurons of myenteric plexus release
ACH and SubP
118
Inhibitory neurons of myenteric plexus release
Dynorphin and VIP
119
Submucosal plexus regulates
Ion and water transport
Glandular secretion
120
90% of serotonin released in gut comes from
Enterochrommafin cells
121
Serotonin is important for
Platelets
122
Serotonin can stimulate inhibitory nitrergic neurons to release
Nitric oxide
123
Serotonin can stimulate cholinergic neurons to release
ACH
124
Visceral Afferent fibers release
Glutamate
125
Steps of G proteins
1. G protein affects adenyl cyclase (ac)
2. AC raised cAMP
3. CAMP stimulates PKA
4. PKA increases membrane permeability to Na and Ca
126
Sweat glands ONLY innervated by
Cholinergic S
127
SNS concentrates gland secretion by
Decreasing blood flow
128
____ largely absent affect on blood vessels
PSNS
129
Regarding the immune system, PSNS, via vagus, stimulates this reflex
Vagal cholinergic anti-inflammatory reflex
130
ACH degraded by
Acetylcholinesterase
131
NorEpi degraded by ___ and ___ or carried away by
MAO
COMT
Blood
132
Precursor for dopamine, NorEpi, Epi
Tyrosine
133
Precursor for ACH
Choline
134
Epi has greater affinity for
Beta receptors
135
NorEpi has equal affinity for
Alpha and beta receptors
136
Alpha and beta receptors are ___
Adrenergic
137
Epi and NorEpi equally potent at
Alpha 1 and alpha 2 receptors
138
ACH receptors can be either ___ or ___
Nicotinic
Muscarinic
139
Nicotinic receptors are blocked by
Curare
140
Muscarinic receptors are blocked by
Atropine
141
Up regulate receptors
Increase number of receptors
142
Down regulate receptors
Decreased sensitivity to NT
143
Denervation supersensitivity
Increased number of receptors
144
Modulation:
| Facilitate release of NorEpi
PACAP
AngII
Corticotropin
Epi
145
Key areas of central autonomic regulation
Amygdala
| Hypothalamus
146
Major motor output of limbic system
Hypothalamus
147
Neural immunoregulation
CNS coordinates host defense activity
148
In segmental facilitation, 1-3 Kg of pressure to abnormal vertebrae will result in
Exaggerated response in adjacent paraspinals
149
The exaggerated response in segmental facilitation could also be observed when decreased pressure applied to
Normal spinous processes above or below lesioned segment
150
Greater than half of primary motor cortex devoted to control o f
Hands and speech
151
With regard to postural control, if descending cortical signals are blocked, what is expected result
Increase extensor tone
152
At the end of a clockwise rotation, what would you expect to happen in VIII CN on left side
Decrease in firing rate
153
After 20 clockwise rotations with eyes closed, rotation stops and eyes are opened. What is observed
Lateral nystagmus with slow component clockwise
154
What would happen to repetitive simple stretch reflex if when the muscle contracts it destabilizes posture
It would be inhibited
155
Strong stimulation of one climbing fiber would elicit which of the following
Complex AP from a few purkinje cells
156
Ventral spinocerebellar tract gains access to cerebellum primary through which peduncle
Superior
