Neuro Exam (Lectures) Flashcards
1
Q
ependyma
A
thin epithelium-like lining of the ventricular system and central canal
some develop into the choroid plexus
2
Q
oligodendrocytes
A
surround and insulate some CNS nerve processes
can simultaneously myelinate MANY axons
3
Q
astrocytes
A
wrap around capillaries and neurons to provide structural support, repair processes, facilitate metabolic exchange between blood and neurons, and help form the BBB
4
Q
microglia
A
resident immune cells of the nervous system
5
Q
resting membrane potential
what does it result from?
A
1) selective permeability
2) differential ionic concentrations across the plasma membrane
maintained by active ion transport Na/K pump
6
Q
signal transduction
A
chemical, temperature, pH, mechanical > electrical > chemical (NTs/peptides)
7
Q
shape of an action potential
A
1) Na+ channels open, Na+ enters cell
K+ channels open, K+ begins to leave cell
2) Na+ channels close
K+ leaves cell
3) K+ channels close
Excess K+ outside diffuses away
8
Q
action potential properties
A
1) All or none
2) AP amplitudes can differ across neurons and neuron types but are a FIXED property of a given neuron
3) frequency of firing encoding information
9
Q
Where are Na+ and K+ channels concentrated on an axon?
A
Nodes of Ranvier
10
Q
benefits of myelin
A
1) decrease capacitance
2) increase membrane resistance
together this increases conduction velocity
3) less biological demand on the neuron
> less channels/pumps expressed
> less energy demand to maintain membrane potential
11
Q
Proteins involved in vesicular release?
A
v-SNAREs and t-SNAREs
botulinum and tetanus toxins are zinc-dependent proteases that cleave VAMP
12
Q
mechanisms for removing neurotransmitter from synaptic cleft
A
1) degradation
2) reuptake
2) diffusion
13
Q
degradation example
A
acetylcholinesterase cleaves ACh into choline and acetate
note: edrophonium short-acting AChE inhibitor used to distinguish clinical btwn MG and Lambert-Eaton syndrome
14
Q
reuptake example
A
monoamines (serotonin, dopamine, glutamine)
note: SSRIs work by inhibiting this mechanism!
15
Q
postsynaptic response
A
1) receptors
2) synaptic integration
3) modulation
16
Q
ionotropic receptors
A
RAPID/TRANSIENT
Nicotinic ACh
NMDA
AMPA
GABAa
17
Q
metabotropic receptors
A
SLOW/SUSTAINED
G-protein coupled
mGlu
GABAb
Muscarinic ACh
B-adrenergic
18
Q
AMPA
A
major mediator of EXCITATORY synaptic transmission
19
Q
NMDA
A
conducts Na+ and Ca2+
Mg2+ blocks the channel and cannot pass current even when NT bound to the receptor
20
Q
what factors influence summation?
A
1) spatial distribution of inputs
2) temporal nature of the inputs
21
Q
endocannabinoid modulation
A
endocannabinoid allows for communication from the post-synaptic cell to the pre-synaptic cell
22
Q
NMJ vs. CNS
INPUTS
A
NMJ: one
CNS: many
23
Q
NMJ vs. CNS
NT
A
NMJ: ACh
CNS: many
24
Q
NMJ vs. CNS
TRANSMITTER REMOVAL
A
NMJ: AChE
CNS: high affinity transporters
25
NMJ vs. CNS
| POST-SYNAPTIC RECEPTOR
NMJ: nicotinic ACh receptor
CNS: metabotropic and ionotropic receptors
26
NMJ vs. CNS
| SAFETY FACTOR
NMJ: very high
CNS: relatively low
27
NMJ vs. CNS
| SYNAPTIC EFFICACY
NMJ: high
CNS: low
28
NMJ vs. CNS
| excitatory vs. inhibitory
NMJ: excitatory only
CNS: both
29
10 Functional Components of Nervous System
1. lateral corticospinal
2. DCML
3. anterolateral
4. basal ganglia
5. cerebellar
6. visual
7. cranial nerves
8. limbic
9. diffuse
10. cerebral cortex
30
specific afferent fibers for sensory detection of fast, well-localized pain
A-delta fibers
31
specific afferent fibers for sensory detection of slow, diffuse pain
C-fibers
32
specific afferent fibers for sensory detection pleasurable touch
A-beta fibers
33
allodynia
pain from a stimulus that does not normally evoke pain
34
hyperalgesia
exaggerated response to a normally painful stimulus
35
taxonomy of pain
nociceptive
inflammatory
neuropathic
dysfunctional
36
nociceptive
no pathology
requires ongoing noxious stimulus
evoked by HIGH-intensity stimuli
37
inflammatory
tissue injury w/inflammation
allodynia, hyperalgesia and spontaneous pain
evoked by LOW and HIGH-intensity stimuli
38
neuropathic
PNS or CNS lesions
allodynia, hyperalgesia, spontaneous pain
sensory amplification
evoked by LOW and HIGH-intensity stimuli
39
dysfunctional (centralized)
altered CNS function (no known lesion/no peripheral pathology)
allodynia, hyperalgesia, spontaneous pain
40
Somatosensory
| specialized receptors
pacinian corpuscles
meissner's corpuscles
c fibers
41
visual
| specialized receptors
photosensitive molecules (e.g., rhodopsin) in photoreceptor cells
42
auditory
| specialized receptors
sterocilia on hair cells
43
Somatosensory
| receptive field of first order sensory neurons
```
a discrete spot on the skin
discrete temperature
pH
taste
odor
```
44
visual
| receptive field of first order sensory neurons
a discrete spot in the visual field (center-surround)
45
auditory
| receptive field of first order sensory neurons
a pure tone (single frequency)
46
Somatosensory
| mechanism of potential change in neurons
physical properties
compression of skin opens FORCE-GATED ion channels
temperature opens THERMAL SENSITIVE channels
47
visual
| mechanism of potential change in neurons
light-activated rhodopsin G-protein mediated effect
48
auditory
| mechanism of potential change in neurons
mechanical displacement of hair cell cilia from sound waves opens FORCE-GATED ion channels
49
```
visual
adaptation (physical changes in receptors)
```
tuned for change, ignore "white space", sense motion
50
```
auditory
adaptation (physical changes in receptors
```
accommodate to loud noises, hear a voice over a drone
51
somatosensory
| location of first order neuron
DRG
52
visual
| location of first order neuron
ganglion cells of the retina synapsing with photoreceptors (rods and cones) in retina
53
auditory
| location of first order neuron
spiral ganglion synapsing with hair cells
54
somatosensory
| higher processing in second-order neurons
shapes, edges of objects being touched
55
visual
| higher processing in second-order neurons
orientation/edges of visual stimuli
56
auditory
| higher processing in second-order neurons
localization of stimulus _ tone; focus on individual speakers over a crowd
57
right-left auditory discrimination
1. right-left ear discrimination of TIME LAG
| 2. right-left ear discrimination of SOUND INTENSITY
58
up-down auditory discrimination
angle sound hits pinna
59
common causes of otitis media
H. influenzae
S. pneumo
Moraxella catarrhalis
60
motor system function: cortex
planning and initiation of voluntary movements and integration of inputs from other brain areas
61
motor system function: basal ganglia
enforcement of desired movements and suppression of undesired movements
62
motor system function: cerebellum
timing and precision of fine movements, adjusting ongoing movements, motor learning of skilled tasks
63
motor system function: brainstem
control of balance and posture, coordination of head, neck and eye movements, motor outflow to cranial nerves
64
motor system function: spinal cord
spontaneous reflexes, rhythmic movements, motor outflow to the body
65
motor system function: muscles
movement of body, sensory organs-muscle spindle and golgi tendon organs
66
motor unit
a single neuron and all the muscle fibers it innervates
smallest division that the system can control individually
either SLOW or FAST
67
innervation ratio
number of muscle fibers per neuron (variable)
eye (low ratio)
quad (high ratio)
68
slow twitch, type 1
darker
aerobic metabolism
contract more slowly
generates less force
69
fast twitch, type 2
paler
anaerobic metabolism
contract quicker
generates more force
70
fast fatigue-resistant
properties that are intermediates between the other two types
71
what does the muscle spindle sense?
length or stretch
72
what does the golgi tendon sense?
tension
73
encapsulated structures mechanically connected in parallel with muscle fibers?
muscle spindles
74
encapsulated structures mechanically connected in series with muscle fibers?
golgi tendon
75
three main components of muscle spindle
1. intrafusal fibers
2. afferent sensory neurons
3. efferent motor neurons (gamma neurons)
76
dynamic bag fibers
respond primarily during CHANGES in the length of the muscle
77
static bag and nuclear chain fibers
primarily signal the length if the muscle without the phasic changes
78
types of infrafusal fibers
dynamic bag
static bag
nuclear chain
79
type of sensory fibers
primary (Type Ia) -terminate on all three types of intrafusal fibers
secondary (Type II)-terminate only on static bag and nuclear chain fibers
Note: cell bodies of sensory afferents in the DRG
80
function of the gamma motor neurons
cause the polar ends of the intrafusal fibers to contract ...maintains the sensitivity of the spindle even when the muscle is shortening
81
UMN Clinical Correlates
lesion above alpha motor neuron
Weakness
No atrophy
Exaggerated reflexes, Positive Babinski
Spasticity
82
LMN Clinical Correlates
lesion of the alpha motor neurons
Weakness
Atrophy
Diminished reflexes, Negative Babinski
No spasticity
83
Examples of Neurogenic Diseases
ALS
Polio
Guillian-Barre Syndrome
84
Example of Myopathic Diseases
Muscular Dystrophy
| Polymyositis
85
Etiology of Neurogenic vs. Myopathic Diseases
Neurogenic-damage to motor neurons
| Myopathic-degenerations of muscle
86
Atrophy?
| Neurogenic vs. Myopathic Diseases
YES BOTH!
87
Fasciculations?
| Neurogenic vs. Myopathic Diseases
Neurogenic -YES
| Myopathic-NO
88
Loss of Reflexes?
| Neurogenic vs. Myopathic Diseases
YES BOTH!
89
Creatine Kinase?
| Neurogenic vs. Myopathic Diseases
Neurogenic-Normal
| Myopathic-Elevated
90
Group 1a Interneuron function
mediate muscle-spindle inhibition of ANTAGONIST muscles in the stretch reflex
receive input from descending tracts
allow for coordination of agonist-antagonist muscles
91
Group 1b Interneuron function
mediate golgi-tendon inhibition of AGONIST muscle
prevent excessive tension
receive multiple muscle, cutaneous, proprioceptive and descending inputs
92
C3, C4, C5
keep the diaphragm alive
93
C5
deltoid
94
C6
biceps
95
C7
triceps
96
C8-T2
Fingers
97
L4
Quads
98
L5
Foot Dorsiflexion
99
S1
Plantar Flexion
100
S2-S5
Sphincter Control
101
UMN + LMN Disease
ALS
amyotrophy-muscle atrophy
sclerosis-scarring
102
nerve typically affected first in ALS
hypoglossal nerve
103
what can cause BG dysfunction?
stroke-lacunar infarcts (GPi/Putamen)
multiple sclerosis
tumor
idiopathic and/or familial
104
Classic Parkinsonian Signs
```
TRAP
Tremor
Rigidity
Akinesia, Bradykinesia
Postural instability (ataxia)
```
105
Basic Life Functions Coordinated by Hypothalamus
```
Energy metabolism
Fluid and electrolyte balance
Thermoregulation
Reproduction
Arousal and Stress Responses
```
106
Hypothalamus gathers information from
```
1. Exteroceptive
visual
somatosensory
visceral (gustatory)
olfactory
multimodal-limbic
```
2. Interoceptive
local: temp, Na, osm, glc
circumventricular organs
107
circumventricular organs
lack a normal BBB
ex. median eminence, pineal gland
108
flip flop switch
mutual inhibition between VLPO and the ascending monoamine systems (no intermediate states!)
VLPO inhibits LC, TMN, Raphe
LC, TMN, Raphe inhibits VLPO
109
reinforces the waking state
orexins (hypocretins)
Orexin activates LC, TMN, Raphe
VLPO inhibits orexin
110
what drives the homeostatic sleep drive?
| when is it at its peak?
adenosine
| right before sleeping
111
when is the circadian sleep drive at its peak?
upon waking
112
hypothalamic output
autonomic: PNS, SNS
endocrine: pituitary
behavior: motor automatisms, arousal, autonomic influences
113
diffuse projecting systems key principles
1. cell bodies occupy very small space
2. projections spread wide
3. branch diffusely
4. secrete NTs and communicate by volume transmission
5. modulate behavioral states
6. evolutionarily conserved
114
synthesis, biogenic amines
amino acid precursor actively transported across BBB
modifying enzymes convert AA to NT
NT
- serotonin
- dopamine
- norepinephrine
- histamine
115
storage, biogenic amines
VMAT2 integral membrane protein transports monoamines into vesicle where they accumulate
116
release, biogenic amines
voltage-dependent calcium channels
calcium influx
vesicle release
117
modulation, biogenic amines
1. high affinity reuptake transporter
2. autoreceptors (can decrease firing and decrease synthesis)
3. degradation/inactivation (oxidation, methylation etc)
118
METH
lipophilic weak base, MAOi
```
can readily cross BBB
looks like dopamine and can be taken up by DAT and transported into synaptic vesicles by VMAT2
alkalinizes vesicle
DA goes back into cytosol, builds up
DAT reverses direction
```
massive DA action and then crash (bc autoregulators)
119
Cocaine
dopamine reuptake inhibitor thus blocking action of DAT
increase of DA in synaptic cleft
autoregulators shut down production of DA
massive DA action and then crash
120
coma
occurs with lesions of the ascending system or with diffuse, bihemispheric dysfunction
121
what determines level of consciousness
ascending system of connections from brainstem and hypothalamus
122
what is wakefulness?
awareness of self and one's environment
123
REM Sleep is?
unconscious but cortex active
dreaming
paralysis
saccadic eye movements
124
NREM Sleep is?
unconscious with little cortical activity
125
somnogens
adenosine
increased during inflammation...more relevant in times of illness
prostaglandin D2
TNF-alpha
126
activity of state-regulatory nuclei
| WAKE
Monoamines
Acetylcholine
Orexin
127
activity of state-regulatory nuclei
| NREM
Monoamines
| GABA
128
activity of state-regulatory nuclei
| REM
Acetylcholine
| GABA
129
what kind of memory does sleep improve
declarative (facts)
procedural (skills)
also helps with consolidation
130
cataplexy
sudden, brief episodes of muscle weakness triggered by strong emotions
131
dysfunction in visual unimodal association area
1. visual object agnosia
2. prosopagnosia
3. simultanagnosia
132
visual object agnosia
cannot recognize visually presented object
a) appreceptive form
impaired ability to perceive the elementary shape of the object
b) associative form
intact ability to perceive the elementary shape of the object
133
prosopagnosia
associated with fusiform gyrus
| inability to recognize faces
134
simultanagnosia
inability to perceive more than one object simultaneously
135
Ballints syndrome
```
simultanagnosia
ocular apraxia (trouble directing eyes)
optic ataxia (impairment in making visually guided arm movements)
```
136
what visual pathway
temporal
137
where visual pathway
parietal
138
lesion in unimodal somatosensory association cortex
tactile agnosia
139
lesion in unimodal auditory association cortex
1) nonverbal auditory agnosia (impaired auditory recognition)
2) pure word deafness (isolates primary auditory cortex from language centers)
140
dysfunction in unimodal motor association cortex
1) low-level apraxia: finely graded finger movement
2) middle-level apraxia: learned skilled movements
2) high-level apraxia: series of acts or sequence
141
Gerstmann's syndrome
lesion in left angular gyrus (junction btwn parietal and temporal)
AGRAPHIA
ACALCULIA
FINGER AGNOSIA
RIGHT-LEFT DISORIENTATION
142
key early events in cerebral cortex development
neural tube closure
| specification/regionalization of neural tube
143
stages of cerebral cortex development
...and broad type malformations
1. proliferation
- > too much
- > too little
2. migration
- > premature termination
- > overmigration
3. neuritic outgrowth/axon guidance
- > incorrect projections/connections
4. synapse formation and pruning/neurotransmission
- > too much
- > too little
5. behavior
144
malformations of cortical development lead to a range of phenotypes but severe malformations often result in varying degrees of with TRIAD OF SYMPTOMS?
Intellectual Disability
Developmental Delay
Seizures
145
ethanol affects which stage of brain development
ALL
146
extracellular cues binds to receptors at the growth cone guide what?
axonal growth
note: growth cone only transiently present
147
many more synapses are produced than are necessary. what glial cell types is responsible for tagging synapses for deletion?
astrocytes
148
cerebral cortex progenitor cells line what structures?
list zones starting from this structure ...
lateral ventricles
```
ventricular zone
subventricular zone
intermediate zone
cortical plate
marginal zone
```
149
cortical plate formation
| name order of layer formation
1 > 6> 5> 4> 3> 2
migrates to final location via radial (excitatory neurons) and tangential (inhibitory neurons) migration
150
three frontal regions
1. lateral prefrontal cortex
2. orbital frontal cortex
3. medial prefrontal cortex
151
lateral prefrontal cortex
involved in working memory
executive function
mental status exam: verbal fluency
cognitive neurosci. task: categorizing, wisconsin card sort test
152
orbital frontal cortex
emotional judgments and regulation
cognitive neurosci. task: iowa gambling task
153
medial prefrontal cortex
initiation, error detection and monitoring of behavior
cognitive neurosci. task: serial reaction time task
154
working memory
the ability to maintain information online and manipulate it to guide behavior
dopamine is critical for function
155
LPFC Circuit
LPFC
medial dorsal nucleus thalamus
lateral GPi/SNr
Caudate Nucleus
input: sensory what and where pathways at LPFC
156
what is verbal fluency? what does it test?
list all the words they can that begin with a specific letter in a minute
normal scores dependent on age and education (12-16/minute)
working memory, LPFC
157
OFC Circuit
```
OFC
medial dorsal nucleus thalamus
ventral GPi
nucleus accumbens
OFC
```
inputs: olfactory, taste, internal body, amygdala @ OFC
outputs: hypothalamus and periaquaductal gray
- cardio
- gastric
- respiratory
- sexual
158
medial frontal regions
```
frontal pole (unknown function) anterior cingulate (monitoring)
supplementary motor (initiate/sequencing)
subgenual cortex (depression)
```
159
causes of aphasia...
stroke (most common cause)
dementia
trauma
brain tumors
160
how are aphasias classified
1) fluency
- ease of speech production
- long phrase length (at least 7 normal)
- small connector words (is, and, the) present
2) comprehension
3) repetition
161
broca's aphasia
comprehension intact
non-fluent speech
poor repetition
associated signs
- right hemiparesis
- apraxia
sometimes called "expressive aphasia"
162
wernicke's aphasia
poor comprehension
fluent speech, non-sensical
poor repetition
poor insight/angry at listener
associated signs
-right homonymous hemianopia
163
conduction aphasia
good comprehension
fluent speech w/phonemic paraphasias
poor repetition
164
role of right hemisphere in language
prosody (non-verbal cues)
humor
theory of mind (ability to attribute mental states to oneself)
165
goal of image-guided neurosurgery
complete resection
no neurological injury
want to see:
- lesion and define margins
- critical structures
- relationship btwn lesion and eloquent areas
accomplish:
- preop planning
- surgical decision making
166
diffusion tensor imaging is a way of mapping what in vivo?
white matter tracts
167
usual localization of tumor in adults vs. children
adults: supratentorial
children: infratentorial
168
what is the only firmly established environmental risk factor for brain tumors?
ionizing radiation
169
parinaud's syndrome
failure of upgaze
pupillary dilation
poor reactiveness to light
retraction nystagmus
assoc. with pineal gland tumor
170
brain tumor diffuse symptoms
```
Headache
Vomiting
Lethargy
Irritability
Behavior change
Increased head circumference
Seizure
```
171
when does a headache become concerning?
```
change in prior headache pattern
unresponsive to prev. effective therapy
focal symptom or sign
worse at night, bending, sneeze, valsalva
vomiting
awakens child from sleep
papilledema
```
172
signs of hydrocephalus
bulging fontanelle
sundowning
increased head circumference
173
brain tumor differential diagnosis
```
stroke/cerebral hemorrhage
abscess/parasitic cyst
demyelinating disease (MS)
metastatic tumors
primary CNS lymphome
```
174
differential of late-life dementia
```
alzheimer's disease
vascular dementia
parkinson's disease with dementia
dementia with lewy bodies
frontotemporal dementias (incl. Picks)
CJD and related prion dementias
```
175
alzheimer's disease defining characteristics
```
amyloid plaques
neurofibrillary tangles
inflammation (microgliosis and astrocytosis)
selective neuronal degeneration
synaptic loss
multiple NT deficits
```
176
neurofibrillary tangles
intraneuronal
| composed of highly phosphorylated forms of the microtubule-associated protein, tau
177
amyloid plaques
extracellular
| composed of 40- and 42-residue amyloid beta-proteins
178
mechanisms of disease in proteinopathies
1. excessive production
2. decreased clearance
3. mutations (missense; expansion)
4. certain biochemical conditions (e.g., extreme pH)
5. failure of chaperone systems
6. prolonged time (age)
179
genetic factors predisposing to AD
APP mutations (ch21)
ApoE4 polymorphism (ch19)
Presenilin 1 mutations (ch14)
Presenilin 2 mutations (ch1)
180
simple, partial seizure
focal, consciousness intact
181
complex, partial seizure
focal, unconscious
182
generalized, absence
motionless starring
loss of awareness
no postictal confusion/immediately resume back to normal behavior
Rx: ethosuximide
183
generalized, tonic-clonic
tonic-stiffening
| clonic-rhythmic jerking
184
generalized, atonic
drop seizure, loss of muscle tone
185
can focal-onset seizures become secondarily generalized tonic-clonic?
YES
186
what is the most common site of focal-onset seizures in adults?
medial temporal lobe
- deja vu
- olfactory and gustatory hallucinations
- fear, anxiety
- nausea
187
epilepsy
tendency towards recurrent, unprovoked seizures
| diagnosed after two unprovoked seizures
188
what factors can affect CNS excitability?
1) intrinsic neuronal factors
(problem with neuron)
2) synaptic or extrinsic/extraneuronal factors
(ex. toxins)
3) neuronal circuit or network factors
(abberant circuits lead to hyperexcitability)
189
Factors important related to recurrence
type
etiology
EEG
190
categories of treatment for epilepsy
```
vagus nerve stimulation
brain surgery
hormonal therapies
ketogenic diet
deep brain stimulation
```
191
stroke ischemic vs. hemorrhagic
85% ischemic
| 15% hemorrhagic
192
T1
CSF dark
good for
- atrophy
- cortical dysplasias
- subacute hemorrhage
193
T2
CSF white
good for
- chronic infarctions
- demyelination
- white matter lesions
- edema/inflammation
194
Flair
T2 with CSF brightness removed
| good for edema
195
Types of Declarative Memory
1) Episodic: ability to re-experience past events
2) Semantic: system for receiving, retaining, transmitting information about meaning of words, concepts and classification of concepts
3) Working: ex. remembering a new phone number while dialing it
196
Types of Non-declarative memory
Procedural (skills)
197
disorders of semantic memory
Is this normal in aging? What diseases are associated?
Spared in normal aging
rare
Viral brain infections
Unusual types of strokes
Semantic dementia
Alzheimers
198
disorders of working memory
Is this normal in aging? What diseases are associated?
Commonly declines in normal aging
commonly affected in neuropsych disorders
```
CVD
MS
TBI
PD
Depression
Schizophrenia
```
199
encoding
what is needed?
the learning of new info
basic attention and working memory are necessary
200
storage
| when does storage happen?
"consolidation"
as time passes, information is less dependent on medial temporal lobe
this happens during sleep
201
retrieval
| names two types
recall (fill info recovered)
vs.
recognition (multi-choice)
202
processes involved in episodic memory
encoding
storage
retrieval
