Exam 3 Flashcards
(208 cards)
1
Q
What does the vestibular system involve?
A
The motor system, hippocampus, and cerebral cortices
2
Q
Name the functions of the vestibular system.
A
- Provides ability to control body and eyes in relation to the environment
- Helps with balance control programming
- Helps keep fluidity by controlling gaze
3
Q
Why is the ear important to the vestibular system?
A
It is a vestibular organ made up of 5 organs
4
Q
What does the ear do?
A
Helps understand which way head moves relative to our body and environment
5
Q
Name the 5 organs making up the ear (vestibular organ).
A
3 semicircular canals
2 otolith organs
6
Q
Name the fluid that fills all parts of the vestibular organ
A
Endolymph
7
Q
What two parts of the internal ear have cells that respond to linear/translational movement?
A
Utricle & Saccule
8
Q
Define linear/translational movement.
A
Movement shared between head and body, or when head and body move at the same rate
9
Q
_____ responds to translational head movement and orientation relative to gravity
A
Otolith organs
10
Q
What special cells are found in the utricle and sacculae?
A
Maculae
11
Q
Define maculae
A
Special cells that pick up direct movement
12
Q
Where in the otolith is maculae found?
A
Utricle & sacculae
13
Q
The semicircular canals respond to _____ movement.
A
Rotational
14
Q
What is the difference between translational/linear movement and rotational movement?
A
Rotational - head and body move differently
Translational - head and body move together
15
Q
Name the 3 planes that organize the semicircular canals
A
Anterior, posterior, lateral
16
Q
What special cells pick up movement in the semicircular canals?
A
Ampulla
17
Q
Name the 5 components of the vestibular system
A
- Sensory receptors
- Nuclei
- Ocular reflex
- Spinal tract
- Vestibulothalamocortical network
18
Q
Name the main sensory receptor of the vestibular system.
A
Hair cells
19
Q
Where are hair cells in the vestibular system found?
A
Inside maculae and ampulla
20
Q
What is found at the top of a hair cell?
A
Kinocilium
21
Q
Relate the kinocilium to the vestibular system
A
Kinocilium makes the hair cells good at detecting movement of endolymph
22
Q
What 2 liquid movements do the kinocilium detect?
A
Left to right & Right to left
* towards shortest or longest hair
23
Q
Describe what occurs when the voltage of the hair cell changes in the direction of the largest hair.
A
The cell will depolarize, raising the resting potential (-60 mV) towards -20 mV. There is an increase in sharing neurotransmitters and a decrease in the firing rate to 10 spikes/second.
24
Q
Describe what occurs when the voltage of the hair cell changes in the direction of the shortest hair.
A
The cell will hyperpolarize, lowering the resting potential (-60 mV) towards -100 mV. There is a decrease in sharing neurotransmitters and an increase in firing rate to 180 spikes/second.
25
The difference in firing rate of the hair cells is the brain"s ______.
Understanding of head rotation
26
Describe the difference in hair cell excitation between turning the head and tilting the head.
When rotating the head, the ampulla will excite in correlation with the direction (i.e. left turn excites left ampulla).
When tilting the head, the kinocilium will not correlate with the direction (i.e. left tilt excites right kinocilium).
27
What movement does the otolith organ respond to?
Linear/Translational - body moves with head
28
What movement does the semicircular canal respond to?
Rotational - head moves independent of body
29
Relate the vestibular nuclei to information transmission.
Information detected from firing rate is sent to brainstem via vestibular nerve, then is sent to *vestibular nuclei*
30
Name the 4 types of vestibular nuclei
1. Superior
2. Lateral
3. Inferior
4. Medial
31
Name the projections of the vestibular nuclei and name the two most important.
**1. Oculomotor nuclei**
2. Vestibulocerebellum
**3. Spinal cord**
4. Reticular formation
5. Thalamus
32
Name the functions of the vestibular nuclei
1. Processes positional & movement info to help control visual & postural reflexes
2. Crosses via commissural fibers, which allow info on left/right side of the body to shared
33
What does the vestibulo-ocular reflex do?
It stabilizes the head during movement
34
Name the function of the vestibulo-ocular reflex.
Helps control your gaze if there's head movement
* When head twists, it keeps constant gaze on subject
35
Name the importance of the vestibulospinal tracts.
It connects the vestibulonuclei with the spinal cord
36
Name the functions of the vestibulospinal tracts.
1. Critical for postural control
2. Excites extensor muscles by ensuring you don't fall over to maintain gaze)
3. Coordinates head movements & axial muscles
37
Name the vestibulospinal tracts.
Lateral & Medial
38
Describe the vestibulothalamocortical network
It is a set of connections of vestibular nuclei to the thalamus then finally to the cortex
39
What does the vestibulothalamocortical network aid in?
Aids in conscious perception of movement and spatial environment
40
How is the vestibulothalamocortical network important for cognitive function?
The brain is able to combine visual and somatosensory information to make more detailed predictions or imaginations
41
Name the 3 meninges of the brain
Dura
Arachnoid
Pia
42
What are the functions of the meninges?
1. Cover and protect CNS
2. Protect blood vessels
3. Contain CSF
4. Form skull partitions
43
Name the function of the subdural and subarachnoid spaces
Have the ability to partition blood, if there is a leakage (e.g. hemorrhaging)
44
Name the functions of cerebrospinal fluid.
1. Buoyancy to prevent crushing
2. Contains nutrients
3. Contains more immune cells after CNS injury
45
Where does CSF originate from?
The first & second ventricles in the choroid plexus
46
Describe the direction of CSF flow
1. Made in choroid plexus in lateral ventricles
2. To 3rd ventricle
3. To 4th ventricle
4. Down dorsal spinal cord
5. Up ventral spinal cord
6. Around cortex and brain
7. Drains into sagittal sinus
8. Ends in the confluence of the sinus
47
Name the landmarks of the brain.
Central sulcus
Lateral sulcus
Longitudinal fissure
Corpus callosum
4 lobes (frontal, temporal, parietal, occipital)
48
Define the central sulcus
Divides frontal and parietal lobes & pre-/post-central gyrus
49
Define the lateral sulcus
Divides temporal lobe from the frontal and parietal lobes
50
Define the corpus callosum
A white matter bundle between hemispheres
51
Describe the functions of the frontal lobe
* Higher cognitive thinking
* Hold & manipulate memory
* Abstract thought
* Goal behavior
52
Describe the functions of the parietal lobe
* Associative integration center
* Manipulation & coordination of things
* Memory and attention
53
Define the functions of the occipital lobe
* Visual information
54
Describe the functions of the temporal lobe
* Perception & memory
* Anything categorical (e.g. faces)
55
Describe what occurs if there is damage to the corpus callosum
The brain is split, possibly forming 2 personalities
56
Name the 6 layers of cortex
1. Molecular
2. External Granular Layer
3. External Pyramidal Layer
4. Internal Granular Layer
5. Internal Pyramidal Layer
6. Multiform
57
Describe the molecular layer of the cortex
Most superficial layer to skull that has short corticocortical association fibers that helps receive & give info to other cortices in the same hemisphere
58
Describe the external granular layer of the cortex
Has cross-hemisphere fibers and helps connect the hemispheres
59
Describe the external pyramidal layer of the cortex
Has cross-hemisphere fibers and pyramidal neurons
60
Describe the internal granular layer of the cortex
Input layer of cortex that receives thalamocortical projects and sensory info
61
Describe the internal pyramidal layer of the cortex
"Upper motor neurons" that projects pyramidal fibers to subcortex and spinal cord that is important in voluntary movement & where the corticospinal tract begins
62
Describe the multiform layer of the cortex
It projects to the cortex and thalamus
63
Describe the appearance and characteristics of pyramidal neurons
They have very long triangular projections and only deal w/ glutamate. They can only be excitatory and make up corticospinal neurons.
64
Describe the appearance and characteristics of non-pyramidal neurons
They have shorter projections that transmit pyramidal signals to nearby neurons. They are spherical, function as interneurons, and can be both excitatory and inhibitory
65
Where can you find pyramidal neurons?
Their bodies are in layers 3, 4, & 5, while their axons are in all 6 layers
66
The pre-central gyrus is dedicated to ____ cortex.
Primary motor cortex
67
The post-central gyrus is dedicated to _____ cortex.
Primary somatosensory cortex
68
What occurs with damage to the frontal lobe?
Drastic changes in personality, social cooperation, and managing oneself socially
* e.g. Phineas Gage
69
Name the two areas of the brain important for speech
Broca's & Wernicke's area
70
Describe the location and importance of Broca's area
Found anterior to pre-central gyrus & is vital for speech production
71
Describe the location and importance of Wernicke's area
Found superior to tempoparietal junction & is vital for speech comprehension
72
Name the function of the hippocampus
Plays a role in memory and forming new memories
73
What occurs with hippocampus damage/removal?
Less seizures & inability to form new memories
* e.g. Henry Molaisson
74
Define the 2 types of amnesia
Anterograde - inability to form new memories post-injury
Retrograde - inability to recall memories pre-injury
75
In the motor system hierarchy, what contributes to the development of motor development?
Parietal/premotoor/supplementart motor cortices
Primary motor cortex
Brainstem
Spinal cord
76
In the motor system hierarchy, what refines movement?
Basal nuclei
77
In the motor system hierarchy, the cerebellum aids in...
error reduction and accuracy
78
The primary motor cortex is where ____ is initiated
The motor program for specific movements
79
Locate the primary motor cortex
Anterior to the central sulcus on the pre-central gyrus
80
The primary motor cortex dedicates neurons to what parts of the body?
Hands , mouth, & face
81
If there is damage to the primary motor cortex, what occurs?
Upper motor neuron syndrom
* Commonly associated with stroke
82
What symptoms occur with upper motor neuron syndrome?
Weakness/paralysis
Hyperactive reflexes
Decreased motor control
Abnormal muscle tone
83
Name the two other motor-related areas of the cortex
Supplementary motor area
Premotor cortex
84
Locate and name the functions and projections of the supplementary motor area.
Found in the medial frontal lobe and plays a role in planning a response before execution, receives information from the parietal lobe.
Projects to primary motor cortex, reticular formation, and spinal cord
* Best for preparation and agency
85
Damage to the supplementary motor cortex can cause ______.
Alien hand syndrome
86
Describe alien hand syndrome.
Typically occurs in one hand or leg & the limb will act independent from the person's desires
87
Describe the role of the premotor cortex
It plays a role in somatotopic organization, movement preparation, and orienting the body for movement. It is important for everything before movement initiation
88
Why is the corticospinal tract important?
For moving face muscles
89
Relate the corticospinal tract to the primary motor cortex
The activation of the primary motor cortex will send signals down the corticospinal tract
90
Which hemispheres control which parts of the face?
Upper face is controlled by both hemispheres
Lower face is controlled by contralateral hemispheres
91
Describe the path a signal takes down the corticospinal tract
The long neurons activate in grey matter
The axons will pass through the internal capsule
The signal will then descend down the brainstem to the pyramidal decussation
92
What occurs with damage to the pons?
Locked-in syndrome
93
Describe the path of the lateral corticospinal tract
It begins in the motor cortex, where 85% to 90% will cross at the pyramidal decussation. It will end in the anterior horn of the spinal cord
94
Describe the path of the anterior corticospinal tract
It descends in the anterior part of the corticospinal tract, where 10% to 15% descend ipsilaterally to the spinal cord.
95
Why is the corticospinal tract divided?
To offer a level os system redundancy in case of damage. Despite split, both tracts carry the same info
96
Define the corticonuclear system.
The cortex that communicates with areas of the brainstem & is dedicated to head and contracting muscles
97
Name the other brainstem tracts
Vestibulospinal tract
Rubrospinal tract
Reticulospinal tract
98
Describe the importance of the vestibulospinal tract
The vestibular nuclei are important activating extensors & anti-gravity/postural, and orienting the head & body in space
99
Describe the importance of the rubrospinal tract
The red nuclei helps controls upper extremities & modify motor performance
100
Describe the reticulospinal tract
The reticular nuclei involved in postures, pain modulation, & visceromotor activity
101
Define innervation ratio
Number of muscles innervated by given motor neurons
102
Relate motor units to force output
Larger motor unit, larger force output
103
How many fibers are associated with small and motor units?
10 to 100 fibers for small motor units
600 to 1000 for large motor units
104
Why is the organization of the axons to muscle fibers important?
The distributed pattern allows muscles to act uniformly rather than staggered activation
* e.g.
105
Define Hennemman's size principle
The size of cell body is proportional to the size of the muscles it innervates & speed of muscle contraction
106
Name the 2 ways force is increased
Increasing motor unit recruitment & unit firing rate
107
As necessary force increases, ______ & ______ increases
Size & voltage
* Bigger size, bigger voltage, bigger force
108
Define twitch
Force in response to one action potentional
109
Define tetanus & name the two types of tetanus
The contraction of muscle in response to stimulation
* Fused & Unfused tetanus
110
Define fused tetanus
Firing rate of action potential exceeds a certain amount, so ceilings are reached for the force output
111
Define unfused tetanus
Easier to decipher because of clear rise and fall
112
Name the two types of muscle fibers
Slow twitch (type 1)
Fast twitch (type 2)
113
Name the characteristics of a slow twitch muscle fiber
Low maximal force
Long contraction time
Fatigue resistant
Produces small force for very long time
* Marathon muscles
114
Name the two types of fast twitch fibers
Fatigue resistant & Fatiguable
115
Name the characteristics of fast twitch fibers
High peak force
Fast contraction time
Fatiguable & Fatigue-resistant fibers
* Sprint muscles
116
Name the two types of human memory systems
Declarative (Explicit)
Nondeclarative (Implicit)
117
Describe the declarative memory system and what categories fall under it.
Consciously accessible and able to be verbalized, relies on hippocampus
* Facts & events
118
Describe the nondeclarative memory system and what categories fall under it.
More difficult to verbalize and accessible through performance, relies on basal nuclei
* Skills & habits
119
What is the importance of the study done by Knowlton et al. (1996)?
They discovered double disassociaton
* They found that the striatum plays a role in skill acquisition & that amnesiacs acquire the tested skill despite not remembering/knowing
120
Define double disassociation
Allows us to understand contributions of specific areas to specific functions
* Like how hippocampus contributes to declarative memory
121
Define spatial memory
Understanding the layout/maps of specific areas
122
Name the function of "place" cells
Help identify our location in a given environment
123
Describe the anatomical pathway to the hippocampus
Sensory cortices to Parahippocampal cortex to Entorhinal cortex to Hippocampus
124
Because of the arrangement, the hippocampus receives...
Rich info about environment, which combines all 5 senses
125
Patients with hippocampal damage have trouble transferring what?
Transferring information from one context to another, making it difficult to memorize or recall
126
If information takes the reverse path out, why does the sensory cortex store some memory
This ensures that there is still some memory intact, making it difficult to forget if it has already been processed by the hippocampus
127
Name the 3 anatomical structures *inside* the hippocampus
Dentate gyrus
CA1
CA3
128
Name the role of the dentate gyrus
Pattern separation
129
Name the role of CA3
Pattern completion
130
The hippocampus is responsible for...
## Footnote
structure of the hippocampus
Pattern separation, pattern completion, & updating information
131
Name the pathway information takes throughout the hippocampus
## Footnote
memory palace
1. Entorhinal cortex
2. Perforant pathway
3. Dentate gyrus
4. Mossy fiber pathway
5. CA3
6. Schaffer Collateral pathway
7. CA1
8. Subiculum
9. Entorhinal Cortex
132
Define retrieval bias
Better at retrieving old information than forming new information
133
How might aging affect dentate gyrus cells?
DG cells will decline, making it harder to separate and form new memories
134
How might aging affect CA3 cells?
CA3 fibers are retained, allowing the remembering of old information
135
Name the 5 recording techniques discussed in lecture
1. Electromyography (EMG)
2. Electroencephalography (EEG)
3. Functional Magnetic Resonance Imaging (fMRI)
4. Transcranial Magnetic Stimulation (TMS)
5. Transcranial Electrical Stimulation (TES)
136
Define motion capture
technique where cameras are used to understand a person's kinematics
137
How is motion capture used in sports therapy?
Able to analyze how players perform pre/post-injury, search for any inefficiencies/progress, and get an idea of potential injury risk, rehab progress, and performance optimization
138
How does EMG work?
electrode(s) records electrical activity in muscles by picking up static and dynamic activity
139
Define the two types of signals an EMG picks up
Active - nerve activity
Reference - activity from sources we don't want
140
Define sEMG (surface EMG)
records whole & superficial muscle activity
* whole muscle
* cross-talk
141
Define iEMG (Intramuscular EMG)
records to pull activity straight from muscle
* few or one motor unit
* invasive, deep muscle activity
* no cross-talk
142
Define EEG (electroencephalography)
records electrical signal given off from pyramidal neurons in brain
143
Define temporal resolution
ability to pick up brain signals at millisecond level resolution
144
Define spatial resolution
ability to localize origin of signal
145
What type of spatial and temporal resolution does an EEG have?
Poor spatial, great temporal
146
What do we use fMRI for?
Used to understand how brain is activated and responds in specific cases
147
What is the unit of measurement for fMRIs?
Teslas
148
Describe how fMRI work with the brain
1. Brain's proton randomly spin
2. W/ fMRI magnet, protons will line up
* This allows signal comparison between different areas
3. Frequency sent to desired area, which moves protons 90 degrees
4. Protons return to uniform direction at different rates
5. If active, relaxation of protons changes as blood goes to different areas
149
Where does the fMRI recording take place?
When protons return to uniform direction at different rates & depending on rate, you can determine measured tissue
150
What does fMRI measure
BOLD activity & oxygen consumption
151
Define BOLD
blood oxygen level dependency
152
Relate BOLD to brain activity
BOLD is the ratio of oxygenated to deoxygenated blood in brain
If an area is more activated, it initially uses a lot of oxygen & oxygenated blood will go to activated site
153
What type of spatial and temporal resolution does fMRI have?
Great spatial, poor temporal
* Opposite of EEG
154
What areas of the brain are activated during motor learning?
Basal ganglia, motor cortex, & supplementary motor area
154
What areas of the brain are activated while encoding episodic memory?
Medial temporal lobes, hippocampus, precuneas, and lateral parietal regions
155
Define functional connectivity
Tells which areas communicate with each other in specific cases
156
Describe how functional connectivity works
If the signal of 2 areas correlate, it is inferred that they are functionally connected.
157
Define TMS (transcranial magnetic stimulation)
A way to excite brain using focal points of magnetism
158
How do we use TMS?
1. Current goes through wires that create Eddy current in brain
2. Magnetic field will penetrate 4 cm deep
3. Eddy current will change activity of brain if delivered in quick pulses
159
What are the pros and cons of TMS?
**Pro**: Only way to study brain causally
**Con**: headaches, seizures
160
What does TMS generate?
A motor-evoked potential that generates twitches and helps analyze changes in corticospinal tract excitability
161
What are the cons of electrical stimulation?
Less controllable, so electricity goes throughout body
162
How does electrical stimulation work?
Ions go from cathode to anode, which will affect voltage at desired area
163
Name the main difference between TMS and ES (electrical stim.)
TMS causes action potentials, ES only makes them more likely
164
What is the order of activation of nerves **in the body**?
Pain
Sensory
Motor
Proprioceptive
Muscle fibers
165
What is the order of activation of nerves **via stimulation**?
Muscle fibers
Proprioceptive
Motor
Sensory
Pain
166
What are H-reflexes and what are they used for?
Signal generated by electrical stimulation & used to measure motor neuron excitability
167
What type of data do you collect through ES?
Stimulus artifact, M-wave, 1A nerve activation, & H-reflex
168
Name the 2 phases of locomotion
Stance & swing
169
Relate H-reflexes to locomotion
High H-reflexes in stance and low H-reflexes in swing
170
Relate H-reflexes to spinal cord injury
H-reflex is exaggerated and wider in spinal cord injuries, which indicate increased muscle spasticity due to less control
171
Define twitch interpolation technique
Patient is asked to perform MVC with electrical stimulation attached to desired muscle
172
How does twitch interpolation work?
If there is additional pulse during MVC, it is assumed that patient is using/recruiting all motor units
173
Name the 2 types of neuromuscular fatigue
Central - performance drops caused by drive coming down from motor cortex
Peripheral - muscle produces specific amount of force within a given timeframe
174
Relate neuromuscular fatigue and motivation
Central fatigue can be overcome by motivation
Peripheral fatigue cannot be overcome
175
Name the 4 indicators of neuromuscular fatigue
1. Decreased max force output
2. Decreased endurance capacity
3. Decreased motor coordination
4. Possible increase of joint stress
176
Name the 3 neuromuscular disorders affected by fatigue
1. Mysathenia gravis
2. Stroke
3. Bedrest/Disuse atrophy
177
Define mysathenia gravis
autoimmune system cells attack muscle receptors, so body struggles with nerve stimulation
178
What is force output dependent on?
1. Motor unit twitch force summation
2. Number of recruited motor units
3. Capacity of muscle
179
The amount of generated force relies on the fusion of _____.
tetanus
180
Name the 3 things that can cause twitch force drop
1. Things that affect intramuscular calcium
2. Things that affect the number of exposed binding sites
3. Things that affect drive from motor cortex
181
Describe the brain and spinal mechanisms related to central fatigue
1. Corticospinal drive
2. Motor neurons
3. Spinal reflexes
182
How do the spinal reflexes influence fatigue?
1. Inhibition from Type 2 & 4 pain afferents
2. Inhibition from GTOs
3. Reciprocal inhibition from Type 1A antagonists
183
What occurs during a MVC?
all units recruited from the start then firing will decline, causing fatigue to occur very quickly
184
In a MVC, the firing rate declines from onset of contraction because of...
1. Inhibition of Alpha motor neuron from 3 & 4 pain afferents
2. Decrease in drive of motor cortex
3. Motor neuron adaptation
185
What occurs during a SVC?
More and more units are recruited as fatigue sets in
186
What occurs during an Isometric submaximal contraction?
Motor unit pool recruitment depends on level of contraction, but new units are recruited during contraction as fatigue sets in
187
What occurs post-peripheral fatigue?
Smaller amplitude & increasing width of twitch force
188
Relate excitation coupling with peripheral fatigue
Disruption in excitation/contraction coupling is a common cause of peripheral fatigure
189
Relate glycolysis to peripheral fatigue
Inefficient glycolysis produces lactate, which results in increased muscle pH & lactic acid buildup
190
What occurs as a result of increased muscle pH and lactic acid buildup?
1. Reduce SCR calcium release
2. Interference with cross-bridge cycle
3. Reduced troponin sensitivity to calcium
191
Relate stress to peripheral fatigue
Stress will restrict blood supply that provides nutrients to muscle
192
How do sensory afferents influence peripheral fatigue?
1. Muscle inhibits spinal cord and premotor cortex
2. Thalamus activated as a result
3. Contraction provides input to autonomic NS, which activates sympathetic NS for mobilization
193
Name the 5 neural strategies to combat fatigue
1. Motor unit recruitment
2. Motor unit synchronization
3. Doublets
4. EMG Bursting
5. Synergistic Muscle Alternation
194
How can motor unit recruitment combat fatigue?
The more recruitment, the easier it is to deal with fatigue
195
How can motor unit synchronization combat fatigue?
Synchronized firing aids with max force output
196
How can doublets combat fatigue?
Doublets help to build up force over small amounts of time
197
How can EMG bursting combat fatigue?
Things like tremors is the body's way of overcoming fatigue
198
How can synergistic muscle alternations combat fatigue?
Muscles will switch on and off to split the overall work load
199
How do imbalances in muscle fatigue rates can influence join pain and possible lead to injury?
One muscle is weaker than the other, leading to less-protected joint stabilizers, affected stance, and nerve pinching
200
What is the metabolic response of **ATP** to endurance training?
Increased ATP storage
201
What is the metabolic response of **glycolysis** to endurance training?
Increased lactate removal
Increased glycogen stores
Increased enzyme activity
202
What is the metabolic response of **Mitochondrial response** to endurance training?
Increased number & size of mitochondria
Increased blood volume
203
Define BDT & its benefits
Ballistic Dynamic Training is completing a MVC in a short time, leading to increased unit recruitment, max force output, & number of doublets
204
What effect does isometric resistance training have?
Firing does not increase, but amount of generated force increases
205
What are the neural adaptations of BDT?
Decreased unit thresholds
Increased doublets
206
What are the neural adaptations of Endurance Training?
Increased amplitude of H-reflexes
207
What are the neural adaptations of Resistance training?
Increased cortical excitability
