PNB 2274 Exam 3 CHEN Flashcards
(191 cards)
1
Q
Dura matter
A
two fibrous layers of dense connective tissue, lymphatic system between the 2 layers with blood vessels and tissue fluids
2
Q
arachnoid layer
A
transparent, epithelial cells, CSF in subarachnoid space
3
Q
pia matter
A
follows brain’s underlying folds, accompanies branches of cerebral blood vessels
4
Q
progressive hypoglycemia
A
low blood glucose; leads to confusion, unconsciousness, death
5
Q
arteries in the brain
A
vertebral and internal carotid arteries
6
Q
veins in the brain
A
internal jugular veins
7
Q
anastomosis
A
vessels joined together
8
Q
colateral circulation
A
provides alternative route for blood supply in the brain in the event of clot
9
Q
circle of willis
A
two vertebral arteries meet to form the basilar artery which connects to the carotid artery to supply blood to the 3 cerebral arteries
10
Q
anterior cerebral artery
A
supplies innerside of brain
11
Q
middle cerebral artery
A
supplies outside of cerebral hemisphere, most likely to clot
12
Q
posterior cerebral artery
A
supplies back of brain
13
Q
blood brain barrier
A
complex that surrounds most blood vessels in the brain that separates the blood stream and the extracellular space in the brain
14
Q
composition of the BBB
A
endothelium cells with tight junctions, astrocytes
15
Q
astrocytes
A
glial cells that have end feet which completely surround blood vessels in the brain; maintains BBB and makes tight junctions stronger
16
Q
function of BBB
A
limits paracellular solute flux, regulates composition and volume of brain interstitial fluid
17
Q
Difference of brain interstitial fluid and plasma
A
interstitial fluid:
- low protein content due to tight junctions which results in a low buffering capacity
- low pH (7.33) due to higher partial pressure of CO2 because brain is highly metabolic
- low glucose concentration because it is transported into tissues of brain
- low potassium levels are needed to establish resting membrane potential
- low bicarbonate ions
plasma:
- higher pH (7.4) due to lower partial pressure of CO2; breathing affects plasma less than interstitial fluid
- higher protein content, better buffer capacity
18
Q
neurovascular unit
A
capillaries, neurons, glial cells, endothelial cells, pericytes –> all play roll in contributing to tight junctions in BBB
critical role in maintaining local blood flow, homeostatic needs, optimizing local signal transduction
involved in many CNS pathologies (blood vessel related, bacterial/virus related, neurologically related, age related)
19
Q
respiratory effects of carbon dioxide induced changes of medullary extracellular fluid pH in cats
A
- inhibition of exhalation increases buildup of CO2 in they system
- buildup increases CO2 partial pressure, magnifying pH change
- chemoreceptor responds to the pH change and activates phrenic nerve to contract the diaphragm
- activation of diaphragm increases breathing effort
20
Q
Why do seizures often accompany brain injuries?
A
Hemorrhagic stroke: when a blood vessel in the brain bursts, the BBB is compromised, making the brain interstitial fluid more saturated with potassium and thus making the membrane more depolarized, bringing Ek closer to threshold. This allows action potentials to fire asynchronously and more often
21
Q
Brain interstitial fluid vs CSF
A
- they are both located outside of the brain cells (extracellular)
- exchange through diffusion
22
Q
Brain interstitial fluid
A
fluid that brain cells (neurons, astrocytes) are bathed in
23
Q
Cerebrospinal fluid
A
liquid surrounding the brain and spinal cord that helps absorb the mechanical shock and maintain chemical stability
found within the brain ventricles, central canal of the spinal cord, subarachnoid space
the wastes generated by brain tissues can be removed as the cerebrospinal fluid continues to circulate
24
Q
cerebrospinal fluid production
A
- produced by the choroid plexus in lateral and 3 ventricles
- intraventricular foramen connects the lateral ventricles, the cerebral aqueduct connects the 3rd and 4th ventricles - CSF leaves the 4th ventricle via paired lateral apertures or single median aperture
- flows through the subarachnoid space and into arachnoid villi and drains into dural venus sinuses
25
sleep experiment
during sleep, glial cells shrink because norepinephrine tells them to, which increases interstitial space to 60% and increases the CSF ability to flush out toxins
26
grey matter
darker, contains nerve cell bodies, dendrites
cerebral cortex and basal ganglia
27
white matter
axons, nerve fibers with myelin sheaths
| commissural fibers, projection fibers, association fibers
28
commissural fibers
fibers that connect one cerebral hemisphere to the other
EX: corpus callosum
29
projection fibers
fibers that connect the cerebrum and other parts of the brain and / or spinal cord
EX: internal capsule
30
association fibers
fibers that connect areas of the cerebral cortex within the same hemisphere
EX: fornix
31
cerebrum
largest, higher brain functions
32
diencephalon
deep, center for homeostasis
| thalamus, hypothalamus, epithalamus
33
cerebellum
impairs motor function on ipsilateral side of the brain/body
- adjusts postural muscles of body
- error correcting during movement
- motor learning and adaptation
- automating and optimizing behavior
cerebrocerebellum, vestibulocerebellum, spinocerebellum
34
neocortical composition layers 1-4
sensory receptors
35
neocortical composition layers 4-6
commander neurons
36
frontal lobe
motor, speech, memory, information, personality, emotion
37
primary motor cortex
sends signals to initiate contraction
38
Broca's area
motor control of language, articulation, tongue control
39
orbitofrontal cortex
judgement, rewards and punishments in relation to a decision
40
olfactory bulb
smell response
41
temporal lobe
hearing, speech, language, smell, info retrieval
42
primary olfactory cortex
sense of smell
43
Wernicke's area
language processing and understanding
44
primary auditory cortex
hearing
45
primary somatosensory cortex
senses touch, pain, temperature
46
parietal lobe
sensation, sensation memories, integration of sensation, proprioception (spacial awareness)
47
somatosensory association cortex
processes information from primary somatosensory cortex
48
primary gustatory cortex
processes taste along with the insular lobe
49
insular lobe
instinct and mood
50
occipital lobe
visual processing and visual memory storage
51
visual association area
interprets info from primary visual cortex
52
primary visual cortex
2D sketch
53
angular gyrus
language comprehension
54
arcuate fasiculus
white matter tract that connects broca's area and wernicke's area (association fibers)
55
damage to Broca's area
unable to speak
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damage to Wernicke's area
speak nonsense / no understanding
57
damage to arcuate and fasiculus
- articulation and understanding is preserved
- speech contains paraphrasic errors
- understands they're making mistakes
- trouble reading out loud or repeating
58
basal ganglia
structures in the cerebral hemisphere that receive input from the cortex and sends output signals through the thalamus to the cerebral cortex
- links complex motivational signals to motor function
- side loop for motor control: gets info from sensory motor cortex which modules muscle tone; prevents unwanted movement
59
huntington's disease
unwanted movement
60
Direct pathway
excitatory; simple, fewer connections
- excitatory neuron from cerebral cortex synapses with an inhibitory neuron which inactivates in inhibitory neuron and excites the thalamus
- inhibits inhibition -- overal is excitatory
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Indirect pathway
inhibitory; more complicated connections
- an excitatory neuron synapses with an inhibitory neuron which inhibits an excitatory neuron in the subthalamic nucleus which excites the globus pallidus and inhibits the thalamus
- overal action is inhibited
62
Parkinsons disease
loss of substantia nigra cells (dopaminergic neurons of basal ganglia)
slow movement
USUALLY:
- inhibitory neuron from substantia nigra acts on the indirect pathway, overall effect is inhibitory
- excitatory neuron from substantia nigra acts on the direct pathway, overall effect is excitatory
63
basal ganglia structures
caudate nucleus, putamen, globus pallidus, claustrum, amygdaloid body
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claustrum
processes visual information
65
amygdaloid body
emotion/mood
66
thalamus
relay center from motor control to cerebral cortex or sensory input to cortex; all conscious senses except for olfactory; GOOD FILTER
67
hypothalamus
command center for autonomic nervous system, endocrine system, regulates homeostatic systems, food and water intake, emotional behavior
NO BBB: secretes hormones in endocrine system
68
pineal gland
secretes melatonin to regulate circadian rhythm
69
brainstem
- bidirectional passageway for all tracts extending between the cerebrum and spinal cord
- autonomic and reflex centers
medulla, pons, midbrain
70
midbrain
motor movement, particularly movements of the eye, auditory and visual processing
tectum, red nucleus, reticular formation, substantia nigra
71
tectum
superior colliculus, inferior colliculus
72
superior colliculus
visual reflex center
73
inferior colliculus
auditory reflex center
74
pons
autonomic respiratory center, cranial nerve nuclei, reticular formation
SURVIVE AFTER CUT
75
medulla
center for cardiovascular regulation and respiratory rhythm generation
NO SURVIVAL AFTER BEING CUT
76
cerebrocerebellum
motor planning; lateral hemispheres
77
vestibulocerebellum
input from brainstem vestibular nuclei, eye and head movement and balance, flocculondar tube
78
spinocerebellum
motor execution
vermis, paravermis
79
vermis
trunk movement
80
paravermis
limb movement
81
two functional brain systems
reticular formation, limbic system
82
reticular formation
receives info from motor cortex, basal nuclei, cerebellum, cranial motor neurons; extends through brainstem and throughout brain
motor functions and sensory functions
83
motor functions of reticular formation
regulates muscle tone at rest, autonomic motor functions (respiratory, cardiovascular, vasomotor)
84
sensory functions of reticular formation
alert cerebrum (reticular activating system), pain modulation, habituation
85
limbic system
ring around diencephalon; emotional function and memory function
cingulate gyrus, hippocampus, parahippocampal gyrus, amygdala, olfactory bulbs, fornix, diencephalon nuclei
86
emotional function of limbic system
emotion and motivational aspects of behavior; provides emotional component to learning process (esp amygdala)
87
memory function of limbic system
hippocampus primarily
88
Kluver-Bucy Syndrome
results from bilateral destruction of amygdala
- decreased emotionality (disinhibited behavior)
- docility (loss of normal response to threats)
- hypersexuality
- hyperorality
- visual agnosia
89
Case of HM
removal of hippocampus to remove epilepsy:
- trouble forming new explicit long term memories
- working memory and procedure in tact
- better in muscle memory games (implicit memory)
90
Explicit memory
facts and events
hippocampus, parahippocampal region, medial temporal lobe
conscious
91
Implicit memory
perceptual and motor skills; reflex
amygdala, striatum, cerebellum
unconscious
92
Short term memory
increases neurotransmitter release
G-coupled receptor releases cAMP which activates protein kinase A, opens calcium channels, vesicular release releases neurotransmitters
93
Long term memory
alters gene expression, transcribes a new protein, and forms more synapses; requires repetition
repetition increases cAMP, which reaches protein kinase A and opens calcium channels --> starts activating and transcribing the gene and gene expression is altered. New protein is present which stimulates growth of axon through branching, forming new synapses and increasing synapse strength
94
left hemisphere
language, math, logic and reasoning
95
right hemisphere
spatial abilities, visual imagery, facial recognition, music
96
cranial nerves
some say marry money but my brother says big brains matter most;
on on on they traveled and found voldemort guarding very ancient horcruxes
97
cranial nerve I
olfactory
98
cranial nerve II
optic
99
cranial nerve III
oculomotor
100
cranial nerve IV
trochlear
101
cranial nerve V
trigeminal
102
cranial nerve VI
abducens
103
cranial nerve VII
facial
104
cranial nerve VIII
vestibulocochlear
105
cranial nerve IX
glossopharyngeal
106
cranial nerve X
vagal/vagus
107
cranial nerve XI
accessory
108
cranial nerve XII
hypoglossal
109
olfactory nerve
smell; sensory
110
optic nerve
vision; sensory
111
oculomotor nerve
4/6 eye muscles; pupil size, eye shape, eyelid
motor
112
trochlear
1/6 eye muscle; motor
113
trigeminal
pain, temperature, touch, chewing
3 branches: opthalamic, maxillary, mandible
greatest sensory function
sensory and motor
114
abducens
1/6 eye muscles; motor
115
facial
facial expression, taste, control of salivary glands, tears (THINK GIANA); sensory, motor, parasympathetic
116
vestibulocochlear
hearing and balance; sensory
117
glossopharyngeal
general taste sensation, 1/3 back of tongue, blood pH, gasses, swallowing, salivary gland
sensory, motor, parasympathetic
118
vagus
swallowing, speaking, visceral sensory, motor, autonomic
sensory, motor, parasympathetic
119
accessory
traps and sternocleidmastoid; motor
120
hypoglossal
tongue, pointed to weakened nerve; motor
121
spinal cord
information integration center
| 31 pairs of nerves exit intervertebral foramina
122
spinal meninges
3 layers, subarachnoid space has CSF, grey matter opposite than brain
123
somatic neurons
skeletal muscle/skin
124
visceral neurons
internal organs / smooth and cardiac muscle
125
ascending tracts
signals to brain
posterior column pathway, spinocerebellar, anterolateral pathway
126
descending tracts
commands to motor neurons
corticospinal pathway, medial and lateral pathways
127
spinocerebellar
position of body, spine to cerebellum
128
anterolateral pathway
pain, temperature, crude touch (sensory)
spinothalamic tract
129
corticospinal pathway
corticobulbar, corticospinal
130
corticobulbar pathway
cortex to brainstem, innervates face and neck
131
posterior column pathway
sensations of discriminative touch, vibrations, joint positions
fasiculus cuneatus
fasiculus gracilis
132
medial and lateral pathways
vestibulospinal
tectospinal
reticulospinal
rubrospinal
133
rubrospinal path
red nucleus, voluntary movement
134
tectospinal
head and eye movement (midbrain)
135
reticulospinal
locomotion, posture
136
sensory receptors
- respond to a particular modality of environmental stimuli
- transduce different forms of sensation to nerve impulses that are conducted to CNS
- perceptions of the world are created by the brain from AP sent from sensory receptors
137
special senses
vision, hearing, taste, smell, equilibrium
138
somatic senses
touch, temperature, pain, itch, proprioception
139
somatic stimuli
muscle length and tension, proprioception
140
visceral stimuli
blood pressure, distension of gastrointestinal tract, blood glucose concentration, internal body temperature, osmolarity of body fluids, lung inflation, pH of cerebrospinal fluid, pH and oxygen content of blood
141
meissner's corpuscle
rapid mechanoreceptor; touch and pressure
142
merkle's corpuscle
slow mechanoreceptor; touch and pressure
143
free nerve ending
slow; nociceptors, thermoreceptors, mechanoreceptors
144
pacinian corpuscle
rapid mechanoreceptor; vibration and deep pressure
145
ruffini corpuscle
slow mechanoreceptor; skin stretch
146
olfactory pathways form nose project through olfactory bulb to the
olfactory cortex
147
sensory pathways project to the
thalamus which relays info to cortical centers
148
equilibrium pathways project to the
cerebellum
149
thermoreceptors
temperature; in skin, muscle, liver, hypothalamus
150
why are there thermoreceptors in the liver?
metabolism: if there is low glucose, thermal generation decreases and changes metabolic process
151
why are there thermoreceptors in the hypothalamus?
it is the thermoregulation center
152
mechanoreceptors
cell is twisted and receptors are activated
tactile
baroreceptors
proprioceptors
153
tactile receptors
touching skin
154
baroreceptors
carotid body, stretching is sensed and tells you how high of blood pressure
155
proprioceptors
tells you where body is, when cell is moved
156
nociceptors
tell you when body is damaged or inflamed -- pain
157
chemoreceptors
general and special; ions and glucose with taste (conscious), pH regulation in brainstem (unconscious)
158
photoreceptors
transduce light into electrical signals
159
categories of sensory receptors
simple, complex
160
simple dendritic endings
free nerve endings, encapsulated nerve endings
161
free nerve endings
pain, temperature, smell
162
encapsulated
pressure and touch, wrapped around nerve endings
when pressure is applied, shape changes and channel gets closed; pressure gets redistributed and cells stop firing
163
complex sensory receptors
separate cell doing transduction work
rods and cones, hair cells, modified epithelial cells
164
hair cells
inner ear telling you loudness, senses balance
165
rods and cones
sight
166
exteroceptors
outside/ external stimuli
167
interoceptors
inside/ internal stimuli
168
proprioceptors
internal stimuli with movement
169
adquate/normal stimulus
the type/modality of stimulus that a receptor is most sensitive to
allows brain to perceive the stimulus accurately under normal conditions
receptor doesn't matter HOW it's activated, it is only giving info on one modality
170
sensory unit
one afferent neuron and all its receptors
171
receptive field
that part of body which when stimulated activates that afferent neuron
172
receptor potential
generated in transduction sites
| amplitude correlates to stimulus intensity
173
stimulus intensity
how the body transmits action potentials and not lose info
1. analog to digital conversion
2. recruitment
174
analog to digital conversion
graded potential to action potential faster or slower
175
recruitment
strong stimulus recruits a neighbor sensory (afferent) neurons to fire action potentials
176
coding of stimulus type
modality, specificity of ascending pathway
177
specificity of ascending pathway
labeled line theory: trace the white matter tract because it tells you the type of info it's sending
178
punctate distribution
point and spotted stimulation -- less than 3mm apart, sticks feel like one poke
179
dorsal column
sensory pathway conveys sensations of fine touch, vibration, two point discrimination, and proprioception
- less divergence and convergence, less branching
180
lateral inhibition
primary neuron response is proportional to stimulus strength; B inhibits A and C
181
presynaptic inhibition
GABA from primary neuron activates calcium channels, therefore less vesicular release
182
tonic receptors
slowly adapting; produce constant rate of firing as long as stimulus is applied (may slowly decrease)
183
phasic receptors
rapidly adapting; burst of activity but quickly reduce firing rate if stimulus is maintained
184
sensory adaptation
neurons/body ceases to pay attention to constant stimuli
185
dorsal column tracts
Fasiculus Gracilis and fasiculus cuneatus and medial leminiscus
186
fasiculus gracilis and cuneatus
slender, myelinated sheaths, ascends ipsilaterally
synapses and crosses medulla
becomes nucleus gracilis and cuneatus when synapses and is no longer white matter fibers
187
medial lemniscus
ascending white matter tract from medulla to thalamus and synapses
188
anterolateral system tracts
spinothalamic, spinotectal, spinoreticular
189
spinothalamic
sharp pain
190
spinotectal
dual burning sensation
191
spinoreticular
dual burning sensation, limbic system, emotional pain
