Exam 2: Neuro Flashcards
1
Q
what are three divisions of the nervous system
A
sensory
integrative
motor
2
Q
what is included in the sensory division of the nervous system
A
tactile
visual
auditory
olfactory
3
Q
what is included in the integrative division of the nervous system
A
process information, creation of memory
4
Q
what does the motor division of the NS allow us to do
A
respond to and move about in our environment
5
Q
the precentral gyri is related to ___________ function
A
motor
6
Q
the post central gyri is related to _______ function
A
sensory
7
Q
the afferent direction is ____________ the nervous system
A
towards
8
Q
the efferent direction is _________ from the nervous system
A
away
9
Q
what nerve ending responds to pressure
A
pacinian copuscle
10
Q
what nerve ending responds to touch
A
meissners corpuscle
11
Q
what joint nerve endings send messages to the DRG
A
kinesthetic receptors
12
Q
what nerve endings respond to pain, cold and warmth
A
free nerve endings
13
Q
What is the role of the thalamus?
A
routes afferent sensory messages to correct portions of brain (muscle cortex, glands, memory etc)
14
Q
what does the temporal lobe do
A
intellectual and emotional functions
memory like face recognition
hearing
15
Q
what actions does the brainstem control
A
swallowing
breathing
heartrate
16
Q
what does the wernickes area do
A
speech comprehension
words/thought
17
Q
what does the cerebellum do
A
coordinates movement and balance
18
Q
what does the occipital lobe do
A
visual
19
Q
what does the parietal lobe do
A
comprehension of language
spanish to english
20
Q
what does the frontal lobe do
A
judgement,
foresight,
voluntary movement
problem solving
organization
21
Q
what does the brocas area do
A
speech
22
Q
what does the frontal lobe/olfactory bulb do
A
smell
23
Q
what are the three levels of CNS function
A
spinal cord
lower brain
higher brain
24
Q
T/F the spinal cord is just a conduit
A
false
25
what is contained in the lower brain level
medulla,
pons,
mesencephalon,
hypothalmus,
thalamus,
cerebellum,
basal ganglia
26
what is contained in the spinal cord level
walking circuits
withdrawal circuits
support against gravity circuits
circuits for reflex control of organ function
27
what does the lower brain level control
subconscious
arterial pressure,
respiration,
equilibrium,
feeding reflexes,
emotional patters
28
what is the role of the higher brain/cortical level
-memory storehouse
-muscle memory
-thought processing
-opens the world up for ones mind
29
T/F the higher brain cortex usually functions alone
False
works with lower centers
30
what are the three major components of the neuron structure
soma
axon
dendrite
31
what is the main body of the neuron
soma
32
which part of the neuron from the soma to the effector part of the neuron
axon
33
which part of the neuron transmits the action potential
axon
34
what is the sensory portion of the neuron
dendrite
35
which part of the neuron conducts electrical charge, not action potentials
dendrite
36
Neuron Structure
37
the posterior portion of the spinal cord is the __________ NS
sensory (afferent)
38
the anterior portion of the spinal cord is the __________ NS
motor (efferent)
39
Where is the grey and white matter in the spinal cord?
grey inside
white outside
40
which root (anterior or posterior) has a ganglion
posterior (sensory)
41
in the brain where is the grey and white matter
White inside
grey outside
42
why is membrane charge close to Ek charge
membrane is very permeable to K
43
what is the nearnst equation
balance of concentration and electrical gradients creates resting potential
44
what two ions are in greatest concentration outside the cell
Na
Cl
45
what ion is in greatest concentration inside the cell
K
46
what offsets the + charge of K inside the cell to make it -
proteins
47
What is a subthreshold stimulus?
weak local depolarization that does not reach threshold
48
T/F subthreshold potentials summate
True
49
T/F action potentials summate
False
50
what an epsp
excitatory post synaptic potential
brings membrane charge closer to threshold (+)
this makes it easier for an AP to occur
51
what type of summation is from the same synapse
temporal summation
52
what type of summation is from different synapse
spatial summation
53
what is an IPSP
inhibitory post synaptic potential
makes membrane
harder to reach AP
54
what is an example of IPSP
seizure meds
55
temporal summation almost ____________ induces an AP
never (he said spatial but book says opposite)
56
how long does an EPSIS/IPSP last
15 mSec
57
each terminal on a dendrite account for _____ - _______ mV EPSP
0.5-1.0
58
the higher number of synapses the ________ likely you are to reach threshold
more
59
what is a facilitated neuron
another neuron fires bringing the potential closer to threshold so the next impulse builds off the first one (summation)
60
Do dendrites transmit action potentials?
no
they conduct electricity
61
why keeps the dendrites from having APs
leaky K and Cl channels keep charge low
No Na channels
62
T/F all neurons have the same activity and frequency
False
different neurons have different activity and frequency
63
what substances are used in ion channel postsynaptic membranes
cation/anion channels
ligand gated chanels (Ach, NE)
64
what type of response do ion channel postsynaptic membranes have
short lived
65
what substances are used in 2nd messenger system postsynaptic membranes
neuropeptides (G protein)
66
what type of responses do 2nd messenger system postsynaptic membranes have
multiple responses
prolonged responses
67
Where are gap junctions found?
cardiac and smooth muscle
68
what is the function of gap junctions
increased speed of conduction of APs between cells
69
what is a second messenger always bound to
G protein
70
second messenger system is a (shorter longer) process than ion
longer
71
what kind of messengers does the second messenger system use
hormones
72
what are the 4 functions of a second messenger system
1) opens channels
2) activates enzymes to produce cAMP or cGMP
3) activates intracellular enzymes
4)activates gene transcription
73
what are some class 1 neurotransmitters
acetylcholine
74
what are some class 2 neurotransmitters
norepinephrine
epinephrine
dopamine
serotonin
histamine
75
what are some class 3 neurotransmitters
gamma-aminobutyric acid (GABA)
glycine
glutamine
aspartate
76
what are some class 4 neurotransmitters
NO (nitric oxide)
77
how does acidosis affect synaptic transmission
depresses neuronal activity
ex. diabetic coma
ph change from 7.4-7.0 results in coma
78
how does alkalosis affect synaptic transmission
increased neuronal excitability
epileptic seizure
ph change from 7.4 to 8.0 results in seizure
79
how does hypoxia affect synaptic transmission
brain dependent on O2
interruption of brain blood flow for 5-10 seconds leads to unconsciousness
80
what do mechanoreceptors detect
deformation
(pressure changes formation of receptors)
81
what do thermoreceptors detect
changes in temperature
82
What do nociceptors respond to?
damage (pain)
83
what do electromagnetic receptors detect
light (like rods and cones in eye)
84
what do rods in eye detect
light
white and black, no color
85
What do chemoreceptors detect?
taste
smell
CO2
O2
86
What does the pacinian corpuscle do?
detects pressure
87
what determines the location of a receptor
their function (idk this is a direct quote)
88
what is a modality of sensation
each of the principal types of sensation: pain, touch, sight, sound
89
what is the the labeled line principle
nerve fibers transmit only one modality of sensation
90
how do all receptors work at a cellular level
they all change the membrane permeability to ions causing either hyper or hypo polarization
91
how does receptor stimulation affect sensation of surrounding receptors
stimulation of one nerve sends a message to surrounding nerves increasing the membrane potential (closer to threshold) so it is easier for the nerve to reach threshold and send AP (facilitated)
92
if a nerve has a node of ranvier it is a ____________ nerve
myelinated
93
how does an increase in stimulus intesity affect AP frequency
increased receptor potential,
which increases AP frequency
94
receptor potential
95
small changes in stimulus strength can be discerned when intensity is _______
low
96
only large changes in stimulus strength can be discerned when intensity is _______
high
97
an increased amplitude of observed receptor potential requires a _________ stimulus strength
increased
98
how does stimulus strength and receptor potential affect a sensation like pain
there is a threshold for how much pain is possible to be perceived
99
what is adaptation of receptors
Neurons stop responding to constant stimuli
100
the fact that your body stops sending you signals about wearing a shirt is an example of what principle
adaption of receptors
101
what are examples of two nerves that adapt very quickly
pacinian corpuscle (stretch)
hair receptor
102
what are examples of two nerves that have slow and limited adaptation
joint capsule receptors
muscle spindle receptors
103
touch sensation adaptation
104
what decreases the distortion force in pacinian corpuscles
fluid redistributes, this is fast adaptation
105
what allows photoreceptors to have fast adaptation
receptors change the amount of light sensitive chemicals
106
what kind of receptor is a pacinian corpuscle
mechanoreceptor
107
is a muscle spindle tonic or phasic?
tonic (slow adapting)
108
is a golgi tendon apparatus tonic or phasic?
tonic (slow adapting)
109
is a ruffini ending tonic or phasic?
tonic (slow adapting)
110
is a merkel disk tonic or phasic?
tonic (slow adapting)
111
is a macula receptor tonic or phasic?
tonic (slow adapting)
112
is a temperature receptor tonic or phasic?
tonic (slow adapting)
113
is a chemoreceptor tonic or phasic?
tonic (slow adapting)
114
is a baroreceptor tonic or phasic?
tonic (slow adapting)
115
is a pain receptor tonic or phasic?
tonic (slow adapting)
116
is a tonic receptor slow or fast adapting
slow
117
a tonic receptor transmits impulses to brain for a ________ period of time
long
118
what kind of receptor keeps us appraised of our surroundings
tonic
119
how long does it take tonic receptors to adapt
hours to days
120
when do phasic receptors respond to stimuli
only when change is happening
121
what affects the rate and response of a phasic receptor
rate and intensity of stimuli
122
what receptors are very important for balance and movement
phasic (fast adapting)
123
Is a Pacinian corpuscle tonic or phasic?
phasic (fast acting)
124
Is a meissners corpuscle tonic or phasic?
phasic (fast acting)
125
Is a semicircular canal receptor tonic or phasic?
phasic (fast acting)
126
what type of receptor continues to respond to stimuli
tonic
127
what type of receptor responds only at onset and offset of stimuli
phasic
128
an A class nerve is (myelinated unmyelinated
myelinated
129
a C class nerve is (myelinated unmyelelinated)
unmyelinated
130
the larger the diameter of the nerve, the _________ the velocity
higher
131
what are the divisions of A classification of nerves from fastest to slowest
A alpha
A beta
A gamma
A Delta
132
what are some of the sensory function of C classification of nerves (unmyelinated)
crude touch and pressure
tickle
aching pain
cold
warmth
133
what is a motor function of C classification nerves
sympathetic
134
a nerve of 20 micrometers moves at a velocity of
120 meters/sec
135
what receptor has the sensory function of proprioception
muscle spindle
136
what are the two ways to increase signal intensity
spatial summation
temporal summation
137
if a nerve is excited, this means it has an
action potential
138
if a nerve is facilitated its membrane potential is changed to be (closer/further) to/from threshold
closer
139
what is a neuronal pool
groups of neurons with special characteristics
140
what are the different types of neuronal pools
converging
diverging
reverberating
inhibitory
141
what are the two type of divergent neuronal paths
same tract
multiple tract
142
what is an example of divergence in same tract
pyramid cells in motor cortex
143
what are examples of divergence in multiple tracts
information from dorsal columns take two directions one to cerebellum and then to thalamus and cerebral cortex
144
what is an amplifying type of divergence
divergence in the same tract
145
what are the two types of convergence neuronal pathways
single source
multiple source
146
convergence from a single source is an example of
spatial summation
147
what controls the antagonistic pairs of muscles
reciprocol inhibition circuit (extensors and flexors have to alternate relaxation and tension)
148
what prevents over-activity in brain
inhibitory circuit
149
what kind of circuit continually fires
reverberatory
150
what are examples of reverberatory circuits
HR,
respiration,
vaso tone
151
what type of feedback do reverberatory circuits have
positive feedback
152
What stops a reverberatory circuit?
fatigue of synaptic junction
153
Do all reverberatory circuits fatigue?
no (vascular tone, gut tone, HR, resp etc)
154
what are examples of tactile mechanoreceptor sensations
touch,
pressure,
vibration,
tickle,
itch
155
what are examples of proprioceptive mechanoreceptor sensations
static position
rate of change
156
what do thermoreceptors detect
heat and cold
157
What do nociceptors respond to?
pain and any factor that damages tissue
158
what is the location of Meissner corpuscles
non-hairy skin close to surface
-fingertips
-lips
-eyelids
-nipples
-external genetalia
159
what is the function of meissner corpuscles
Motion detection, grip control
160
what is the stimuli for meissner corpuscles
skin motion, low frequency vibration
161
what is the nerve type of meissner corpuscles
type A beta nerve fibers
162
what is the location of merkel discs
tip of epidermal ridges
163
what is the function of merkel disks
form and texture perception
164
what is the stimuli for merkel disks
edges, points, corners, curvature
165
what tactile receptors help you differentiate between picking up a ball or block
merkel disks
166
what is the nerve type of merkle disks
type A beta fibers
167
what is the location of pacinian corpuslce
dermis and deeper tissues
168
what is the function of pacinian corpuslces
perception of distant events through transmitted vibrations
169
what is the stimuli of pacninian corpuscles
vibration
170
what is the nerve type of pacinian corpuscles
type A beta nerve fibers
171
what is the location of ruffini corpuscles
dermis (joint capsules)
172
what is the function of ruffini corpuscle
tangential force,
hand shape,
motion detection
173
what is the stimuli of ruffini corpuscle
skin stretch
174
what is the nerve type of ruffini corpuscle
type A beta fibers
175
what is the location of free nerve endings (myelinated)
surface of body and elsewhere
176
what is the function/stimuli of free nerve endings (myelinated)
pain
temp
177
what is the nerve type of free nerve endings (myelinated)
type A delta
178
what is the location of free nerve endings (unmyelinated)
surface of body and elsewhere
179
what is the function/stimuli of free nerve endings (unmyelinated)
pain
temp
itch
tickle
180
what is the nerve type of free nerve endings (unmyelinated)
type C
181
what are the two pathways for sensory afferents
anterolateral system
dorsal column-medial lemniscal system
182
where do all sensory afferents first go to on spinal cord
posterior root ganglion
183
dorsal column-medial lemniscal system has _________ (#) of nerves in the spinal cord
1, goes straight up to medulla oblongata
184
the anterolateral system enters the dorsal root and has a synapse that crosses the ____________ and goes up the __________
anterior commissure
anterolateral tract
185
the anterolateral system has ___ (#) of nerves in the spinal cord
2, crosses the anterior commissure
186
white matter is made up of
pathways
187
dorsal column-medial lemniscal pathway is made up of ________ myleninated nerve fibers
large
188
What is decussate?
where sensory nerves cross over to the opposite side of the nervous system
189
how many neurons are involved in the dorsal column-medial lemniscal pathway
3
190
where does the dorsal column-medial lemniscal pathway decussate
medulla oblongata (lower)
191
after crossing over in the medulla oblongota the dorsal column-medial lemniscal pathway goes through the _____________ to the ____________
medial lemniscus
ventrobasal complex of thalamus
192
where does almost all sensory afferents go
ventrobasal complex of thalamus
193
where does the third nerve of the dorsal column-medial lemniscal pathway synapse
ventrobasal complex of thalamus,
terminate in cortex
194
what type of mechanoreceptor information is transmitted in the dorsal column-medial lemniscal pathway
discrete types with a high degree of spatial fidelity
(touch, vibration, position, fine pressure)
195
what kind of neurons are in the anterolateral system
smaller myelinated and unmylinated fibers for slow transmission
196
how many neurons are involved in the anterolateral system
3
197
where does the anterolateral system decussate
spinal cord
198
the anterolateral system has a ______ degree of spatial orientation
low
199
what sensations are transmitted in the anterolateral system
pain,
thermal,
crude touch,
pressure,
tickle,
itch,
sexual sensations
200
where does the third neuron of the anterolateral system synapse
ventrobasal and intralaminar nuclei of the thalamus, terminates in cortex
201
what is the greatest area of representation of somatosensory cortex
1- lips
2- face
3- tongue
202
what areas have the least representation of somatosensory cortex
trunk and lower body
203
what determines where a sensation goes in brain
thalmus
204
what layer do all incoming signals go
4
205
how many layers does the structure of the cerebral cortex have
6
206
layers can have _________ columns of modality
multiple
207
where is layer 1 in the cortex
near the surface
208
where is layer 6 in the cortex
deep
209
what layers receive diffuse input from the lower brain centers
layer 1 and 2
210
what layers send axons to closely related portion of the cortex for communicating between similar areas
2 and 3
211
what layers send axons to more distant parts of the nervous system
5 and 6
212
where does layer 5 send signals
brainstem
213
where does layer 6 send signals
thalamus
214
a column in the cortex represents what
a specific sensory modality (stretch, pressure, touch, etc)
215
a small stimuli on a single point will stimulate (less/more) receptors than a large single point stimimuli
less
216
what is lateral inhibition
when an excited neuron reduces the activity in neighboring neurons
narrows area of sensation
217
what disease follows a dermatome
varicella (shingles)
218
dermatomes
219
what is a dermatome
area of skin supplied by a sensory neuron that arise from a spinal nerve ganglion
220
what kind of stimuli cause fast pain
knife cut, needle poke, burn
221
where is fast pain stimuli usually felt
surface of body
222
where is slow pain usually felt
body surface and deeper tissue
223
what kind of stimuli cause slow pain
throbbing/aching
224
what type of pain is bradykinin associated with
slow pain
225
fast pain travels on _______ nerves
myelinated
226
what is the main cause of pain from tissue damage
bradykinin
227
slow pain travels on ______ or ______ nerves
small myelinated or unmyelinated
228
what are the three signs of inflammation
heat, redness, swelling
229
what are some inflammatory mediators
bradykinin, prostaglandin,
230
what kind of receptors are pain receptors
free nerve endings
231
where are free nerve endings located
skin,
arterial wall,
joint surfaces,
periosteum,
falx and tentorium of cranial vault
232
do pain receptors adapt to stimuli?
no
233
what is intensity of pain related to
rate of tissue damage
234
what contributes to pain resulting from tissue damage (slow pain)
bradykinin
potassium
proteolytic enzymes (neutrophils)
235
What causes emphysema?
neutrophils dissolving elastin around alveoli,
236
what is ischemia
lack of blood flow
237
what is hypoxia
lack of o2
238
what causes ischemic pain
lactic acid build up (death of tissue)
bradykinin
proteolytic enzymes
239
how long does it take for pain to occur in arterial occlusion of limb
15-20 seconds
240
what kind of pain travels in the neospinothalamic tract
fast pain
241
what fibers transport the fast pain
type A delta
242
what fibers transport slow pain
type C fibers
243
what kind of pain travel in the paleospinothalamic tract
slow pain
244
where does the first neuron of the neospinothalamic tract travel
into posterior horn, up or down 1-2 segments, terminates in posterior horn in lamina marginalis
245
what is the path of the second neuron in the neospinothalamic tract
1. starts in posterior horn lamina marginalis
2. immediately crosses over the anterior commissure to the anteriolateral column
3. travel up to the reticular formation of the ventrobasal complex of the thalamus
246
what is the neurotransmitter for A-delta fiber of neospinothalamic tract
glutamate
247
what lamina is the lamina marginalis in
1
248
what lamina is the substantia gelatinosa in
2-3
249
what lamina do Ad pain nerves (neospinothalamic) dessucate in
1 Lamina marginalis
250
what part of the spinal cord does the 2nd neuron of the neospinothalamic tract travel on
anterolateral column
251
where do most 2nd order neospinothalamic tract nerves terminate
ventrobasal complex of the thalamus
252
where do 3rd order neurons of the neospinothalamic tract travel to
cortex
253
can fast, sharp pain (neospinalthalamic) be localized well?
yes, when other tactile receptors are also stimulated
254
what happens with pain receptors in retricular formation
pain sensations get dissipated to trigger other portions of brain
255
what pathways use the anterolateral pathway
tactile,
neospinothalamic,
paleospinalthalamic
256
how many neurons are in the neospinothalamic tract
3
257
where does the neospinothalamic tract decassate
within spinal cord
258
what stimulates the tactile plate? what does it do
pain
releases endogenous pain relief
259
what type of nerve fiber is used in the paleospinothalamic tract
C fiber
260
what type of pain is transmitted in the paleospinothalamic tract
slow, burning pain
261
where does first neuron of the paleospinothalamic tract synapse
2 and 3 (substantia gelatinoa), or lamina 5
majority will go synapse in 5 first
262
where do all neurons of the paleospinothalamic tract synapse before crossing to the anterolateral pathway
lamina 5
263
what is the neurotransmitter for type C fibers of the paleospinothalamic tract
substance p
264
does the paleospinothalamic tract localize well
no
just to affect limb
265
where do most nerves of the paleospinothalamic tract terminate
reticular nuclei of medulla, pons, mesencephalon, and tectal area of mesencephalon and periaqueductal gray area
10-25% in thalamus
266
what types of pain does substance P mediate
lower back pain
arthritis
fibromyalgia
267
how does capsaicin work
depletes substance P from local nerve endings to relieve pain
268
if you remove the somatic sensory sensory area of the cortex will you still feel pain?
yes, pain has branching pathways (reticular areas)
269
what area of the brain is important for determining the quality of pain
cortex
270
where does endogenous analgesia begin
reticular formation
periventricular nuclei
periaqueductal gray
271
what does the raphe magnus/nucleus release when stimulated
serotonin
272
what stimulates the enkephalin system
serotonin
273
when nucleus raphe magnus is stimulated and releases serotonin what happens next
the enkephalin neuron inhibits pain transmission in spinal cord
274
what does naloxone do,
stops the enkephalin neuron from tying up pain receptor neuron
275
what 4 sites can stimulate endogenous analgesia by blocking the anterior lateral pathway
parabrachial nucleous
medullary reticular formation
raphe nuclei
locus coerleus
276
where is serotonin released from in endogenous analgesia pathway
raphe nuclei
277
what can cause both presynaptic and postsynaptic inhibition of incoming type C and tybe A delta fibers where they synapse in in dorsal horn
enkephalin
278
what is an example of higher brain centers controlling pain
placebo affect
279
what are the major endogenous opiates
beta-endorphin,
dynorphin
met-enkephalin,
leu-enkephalin,
280
where are enkephalins and dynorphins found
brain stem
spinal cord
281
where are beta-endorphins found
hypothalamus and pituitary
282
when is the endogenous opiate system activated
pain suppression during stress
response to emergency
defense, predation, dominance
adaptation to environmental challenges
283
what is the gate theory of pain
stimulation of type A-beta fibers from peripheral tactile receptors can decrease transmission of pain signals
284
what are examples of using the gate theory of pain
electrical stim
massage
liniments
285
what form of gate theory of pain can reduce labor pain
audioanalgesia
286
how many pain receptors do visceral tissues have
few
287
what are common causes of visceral pain
ischemia
chemical irritation
spasm of a hollow viscus
over-distension of a hollow viscus
288
where is pain from internal organ often felt
distant area of skin, this is referred pain
289
what is phantom pain
pain in a missing limb
290
what is the mechanism of referred pain
intermingling second order neurons in dorsal horn of spinal cord from skin and viscera (relatedto embyronic development)
291
why do MIs cause L arm pain
referred pain
292
what causes the specific location of referred pain of an organ on the skin
dermatome of embryonic development
293
where is heart pain localized
neck
left shoulder
left arm
294
where is stomach pain localized
above umbilicus
295
where is colon pain localized
below umbilicus
296
does headache pain come from the actual brain
no, brain tissue is insensitive to pain
297
where are the pain senstive areas in the head that are related to HA
dura
blood vessels of the dura
venous sinuses
middle meningeal artery
298
what causes eye headaches
computer use
needing glasses
299
what causes sinus HA
sinusitis
300
HA pain form the superior surface of the tentorum cerbellum forward manifests as what kind of HA
cerebral vault HA (top and side of head) meningitus, middle meningeal artery
301
HA pain from the inferior surface of the tentorum cerebellum backward manifests as what kind of HA
brain stem and cerebellar vault HA
302
what causes intracranial HAs
meningitis
migraine
hangovers
303
what causes migranes
vasospasm followed by prolonged vasodilation
vasodilitation stretching of blood vessels
304
what causes hangover HA
irritation of meninges by alcohol breakdown products
305
what causes extracranial HAs
muscular spasm (tension HA like TMJ, also emotional tension)
sinus HA
eye strain
306
we have more (hot/cold) receptors that we do (hot cold) receptors
cold
hot
307
where is the highest density of cold receptors
lips
308
T/F freezing cold and burning hot are the same sensations
T, when intense it stimulates pain so it feels the same
309
how does cold and hot stimulate nerves
changes the metabolic rate around receptor, so changes rate of intracellular reactions and ion interactions
310
cold changes ____________ metabolic rate
decrease
311
heat changes __________- metabolic rate
increase
312
what are the three sub areas of the motor cortex
primary motor cortex
premotor area
supplemental motor area
313
What does the primary motor cortex do?
controls the primary movement (like raising arm to climb up ladder)
314
What does the premotor area do?
stimulates related muscle groups to allow the primary movement
(shoulder and elbow and hand movement to raise arm when climbing ladder)
315
what are mirror neurons
anterior portion- builds image of action while posterior portion puts it into affect (part of premotor)
316
mirror neurons are part of which area of the motor cortex
premotor area
317
what does the supplemental motor area do
works with premotor area to elicit bilateral movement
(when climbing a ladder tells the rest of the body how to get into position to support primary movement)
318
sensory is the ___________ gyrus
posterior
319
motor is the __________ gyrus
anterior
320
what supples the broca area
first branch of the middle cerebral artery
321
what happens when broca area is damaged like in stroke
decreased speech capacity
322
what are specilized areas of the motor cortex
broca area
eye fixation and head rotation
hand skills area
323
what does the eye fixation and head rotation area do
for coordinated head and eye movement
324
what does damage to the hand skills area lead to
motor ataxia,
inability to perform fine hand movements
325
what transmits corticol motor signals on the direct pathway
corticospinal tract
326
what pathway transmits discrete detailed movement
direct pathway/corticospinal tract
327
what does the indirect pathway of cotricol motor signal
basal ganglia,
cerebellum,
brainstem nuclei
328
what percent of the corticospinal tract comes from the primary motor cortex
30
329
what percent of the corticospinal tract comes from the supplementary motor areas
30
330
what percent of the corticospinal tract comes from the somatic sensory areas
40
331
where do the majority of the fibers of the corticospinal tract dessucate
pyramid of medulla oblongota
332
after dessucating in the medulla where do corticospinal tract fibers travel
lateral corticospinal tracts
333
the majority of every type of nerve fiber dessucate in the
medulla oblongota
334
what type of fibers come out of the giant pyramidal cells (betz cells)
large fibers with fast transmission (70 m/sec)
335
lateral corticospinal tract crosses over at the
medulla oblongata
336
ventral corticospinal tract crosses over at the
cervical or spinal area
337
betz cells make up about ______ percent of total fibers
3%
338
how many muscle fibers do we have
1 million
339
why do we have large betz cell fibers for the motor transmission
creates immediate muscle response
340
what is the collateral response of the betz cells
send message back to cortex to sharpen the boundaries of the excitatory signal
341
what do motor fibers to caudate nucleus and putamen do
controls body posture (spinae erectae)
342
what does the reticular formation do
reacts to pain stimuli
343
what connects the hemispheres of the brain
corpus callosum
344
how many ways do somatosensory side comunicate to motor side
5
345
what tract does the red nucleous work with
rubrospinal tract
346
where does the red nucleous and rubrospinal tract receive input from
primary motor cortex
347
what is contained in the magnocellular portion of the red nucleus
large nuerons similar to betz cells
348
the magnocellular portion of the red nucleus gives rise to the
rubrospinal tract
349
the magnocellular portion of the red nucleus has somatotopic organization similar to the
primary motor cortex
350
what kind of movement does red nucleus stimulate
relatively discrete movement
351
which is more discrete primary motor cortex or red nucleous
primary motor cortex
352
what gives sensory feedback for motor control system
muscle spindles,
tactile receptors,
propioceptors
353
what does sensory feedback from motor control system do
fine tunes muscle movement (how tight to hold a can)
354
what causes auto correction in muscle spindle
length mismatch
355
what is an example of compression of skin provides sensory feedback to motor cortex on degree of effectiveness of intended action
holding an object, how tight to hold
356
how many giant pyramidal cells are need to cause muscle contraction
50-100
357
what layer of the cortex are motor neurons in
layer 5
358
what does a lesion in the primary motor cortex cause
loss of voluntary control of discrete movement of the distal segments of the limbs
359
what do lesions of the basal ganglia cause
muscle spasticity from loss of inhibitory input from accessory areas of the cortex that inhibit excitatory brainstem motor nuclei
360
what part of body does brainstem area contol
motor and sensory functions of face and head (cranial nerves)
361
the brainstem is an extension of the
spinal cord
362
where are centers for stereotypic movement and equilibrium contained
brainstem
363
what muscles support the body against gravity
muscles of spinal column and the extensor muscles of the legs
364
what excites the antigravity muscles
pontine reticular nuclei
365
what inhibits the antigravity muscles
medullary reticular nuclei
366
what tract does the medullary reticular nuclei use to oppose antigravity
medullary reticulospinal tract
367
where does the medullary reticulospinal tract receive input
corticospinal tract,
rubrospinal tract,
other motor pathways
368
muscles that support the body against gravity are under the influence of the
brainstem nuclei
369
what are the components of the vestibular apparatus
semicircular ducts (canals)
utricle
saccule
370
where are the maculae located
utricle and saccule of the vestibule
371
what does the vestibular apparatus do
maintains equilibrium/balance
372
the maculae of the urtical responds to _________- movement
horizontal
373
the maculae of the saccule responds to _________ movement
verticle
374
what are the layers of the maculae
statoconia (weighted pebbles)
gelatinous layer
hair tufts (in gelatin layer)
hair cells
nerve fibers
375
weighted stataconia move in the (same/opposite) direction of movement
opposite
376
Where are crista ampullaris/cupula located?
in the ampulla of each semicircular canal
377
How many semicircular canals are there?
3 (anterior, posterior, lateral)
378
What are the semicircular canals filled with?
endolymph
379
what are the small protrusions of the hair cell called
stereocilia
380
what is the one large protrusion of the hair cell
kinocilium
381
movement towards the kinocilium of the hair cell causes cellular
depolarization (opens pores)
382
movement away from the kinocilium of the hair cell causes
hyperpolarization
383
what connects the steriocilia and kinocilium
filament attachements
384
each semicircular canal has an _________ where the cupula and cristae ampullaris are located
ampulla
385
all the semicircular canals are at a _____ degree angle to eachother
90
386
what structures tell our brain about equilibrium
vestibular apparatus
387
what nerve transmitts the information from the vestibular appartus
vestibular nerve
388
where does the vestibular nerve travel
vestibular nucleus in medulla oblongata
389
what motor systems use the autonomic nervous systme
visceral organs,
blood vessels,
secretory glands
390
where are cell bodies of preganglionic ANS located
brain stem or spinal cord
391
axon of the visceral motor neuron is ___________ myelinated and projects to the ____________ ganglia
thinly
autonomic
392
cell body of the postganglionic neuron of the ANS are located within the ___________ ganglia and the _____myleninated axon projects to visceral effector cell
autonomic
UN
393
what are the divisions of the ANS
sympathetic and parasympathetic
394
sympathetic have ________ preganglionic fibers and _______ postganglionics
short
long
395
parasympathetics have __________preganglionic fibers and _______ postganglionics
long
short
396
All postganglionic parasympathetic neurons release ______.
acetylcholine
397
All preganglionic axons of the autonomic nervous system release
acetycholine
398
what is pathway of norepi synthesis
tyrosine-DOPA-dopamine-norepi
399
what is acetylcholine made up of
acetyl CoA and choline
400
what receptors does norepinephrine stimules
alpha and beta adrenergic
401
where are alpha receptors located
blood vessels (vasoconstriction)
402
Where are beta 1 receptors located?
heart (increase HR and contractility)
403
where are beta 2 receptors located
skeletal muscle,
lungs
bronchial dilation
vasodilation in muscle
calorigensis
glycogenolysis
404
what receptors does acetylcholine activate
nicotinic and muscarinic
405
Where are nicotinic receptors found?
neuromuscular junction, synapses between pre and post ganglionic neurons
406
Where are muscarinic receptors found?
all effector cells stimulated by postganglionic parasympathetic fibers (glands?)
407
what does sympathetic stimulation of the eye cause
pupillary dilation
408
what does parasympathetic stimulation of the eye cause
pupillary constriction and accommodation (focusing) of lense
409
what glands does the parasympathetic stimulate
nasal,
lacrimal,
salivary,
GI glands
410
what glands does the sympathetic stimulate
sweat
411
how does sympathetic affect the GI
none
412
how does parasympathetic affect the GI
stimulates overall activity and GI smooth muscle
413
how does sympathetic affect the heart
increased HR and contractility
414
how does parasympathetic affect the heart
decreased HR
415
how does sympathetic affect blood vessels
vasoconstriction
416
how does parasympathetic affect blood vessels
SOME vasodilation, but this is mostly done by suppressing sympathetic
417
parasympathetic has __________ receptors
cholinergic
418
sympathetic has _______- receptors
adrenergic
419
which part of the ANS is the adrenal medulla related to
sympathetic
420
what percent of epi and norepi is released from adrenal medulla
80% epi
20% norepi
421
What is the role of the adrenal medulla?
facilitates sympathetic
helps body deal with stress
422
where does sympathetic affect "tone"
venous system-constant tone
423
where does parasympathetic affect tone
GI
424
where do parasympathetic nerves come from
discrete brain stem and sacral 2-4
425
what causes the bodies stress response
sympathetic ANS
426
what is affect of SNS response (fight or flight)
increased BP, HR, Contractility, blood flow to muscles, blood glucose, metabolic rate, muscle strength, mental activity, blood coagulation
427
what are examples of adrenergic/sympathomimetic drugs
phenlyephrine (alphas)
isoproterenol (beta 1 and beta 2)
albuterol (beta 2)
428
what drug can treat collapsing trachea
isoproterenol
429
what does the splachnic nerve stimulate
viscera
430
where does the splachnic nerve come from
sympathetic chain ganglion
431
what are the three pathways in the sympathetic chain ganglion
1) enter via the white ramus and terminate
2)enter the sympathetic chain and go up or down a few segements and terminate
3)enter via the white ramus and exit via the splachnic nerve and terminate in a prevertebral ganglia
432
what cranial nerves do the parasympathetic nerves come from
3
7
9
10
433
what is cranial nerve 3
Occulomotor (eye movement) pupillary sphincter and ciliary muscles
434
what is cranial nerve 7
Facial (nerves to nasal, lacrimal, and submandibular gland)
435
what is cranial nerve 9
glossopharyngeal (parotid gland)
436
what is cranial nerve 10
vagus
437
what is another name for the parasympathetic splachnics
sacral segments (2-4)
438
where do the sacral segments of PNS go
fibers go to colon, rectum, bladder, genitalia
439
what postganglionic SNS nerves dont release norepi
sweat glands,
piloerector muscles,
and select blood vessels
440
what breaks down acetylcholine
acetylcholinesterase
441
what drugs increase the release of norepi from storage terminals
ephedrine, tyramine, amphetamine
442
where are nicotinic receptors located
muscles
ANS preganglion
443
what drug do you not give in glaucoma
atropine, use pilocarpine instead
444
what are examples of antimuscarinics
atropine, scopolamine
445
what are examples of cholinesterase inhibitors
neostigmine, pyridostigmine, ambenonium
446
cessation of cerebral blood flow for ______ to ______ seconds results in LOC
5-10
447
what percent of blood goes to brain
15% (750-900 ml min)
448
what are the metabolic factors that effect blood flow
Co2, H, O2
449
what are the 4 arteries that supply the circle of willis
internal carotids and vertebral arteries
450
The brain has a ___ metabolic rate
high
451
how can we measure Cerebral blood flow
functional MRI
positron emission tomography
452
why do we have the cerebral circle
if there is an occlusion on one part, blood flow can still continue from other parts of the circle
453
What is the body's main source of energy?
glucose
454
does the brain require insulin?
no
455
what can too much insulin cause in the brain
decreased blood glucose, leads to psychosis and coma
456
how long of a glucose supply does the brain have
2 min
457
where is the brains supply of glucose
glycogen in neurons
458
increased CO2 casues vaso___________
dilation
459
what does an increase in CO2 leading to an increase in H in brain lead to
increased blood flow
decreased neuronal activity
460
nueral activity of the brain is increased during what acid base condition
alkaline
461
how do astocytes increase blood flow
nervous activity = glutamate
glutamate = calcium wave
calcium wave = prostaglandins
prostaglandins= dilation
462
what pressures does CBF autoregulation keep
60-140
463
what can pressure of >160mm hg in brain lead to
blood vessel stretch, eventual rupture and stroke
464
how much CSF is formed each day
500 ml (600?)
465
what produces CSF
the choroid plexus in the lateral (2), third and fourth ventricles
466
what cushions the brain and allows it to float
CSF
467
how much CSF is in the head usually
150ml
468
how much volume can the cranial vault hold
1600mls
469
all fluids in body (including csf) end up in
venous system and then urinated out
470
CSF is similar to
plasma
similar concentration
471
where is CSF and vessels in brain
sub arachnoid space
472
Where is the perivascular space?
space between blood vessel that goes into brain and pia.
473
what is perivascular space
specialized lymphatic system of the brain for CSF
474
what med do we use to treat cerebral edema
mannitol
475
what happens to CSF in increased ICP
CSF is lost
476
what causes papilledema
elevated ICP
477
what is normal ICP
8-15 mmHg
478
What does the BBB protect the brain from?
changes in ions,
AA,
peptides that occur in blood
479
where is BBB located
capillary endothelial cells
480
can H go through BBB
NO
481
can lipid soluble things go though BBB
yes
482
can CO2 go through BBB
yes
a gas
483
what are causes of ischemic stroke
thrombosis (local clot)
emobolism (clot from somewhere else)
hypotension (schock)
venous thrombosis
484
what are the two types of strokes
ischemic and hemorrhagic
485
What percent of strokes are ischemic?
87%
486
where do most ischemic strokes come from
carotid, cause of carotid sinus
487
what is synaptic fatigue
exhaustion of stores of transmitter in synaptic terminals
excitatory synapses are repetitively stimulated at a rapid rate until post synaptic discharge becomes progressively less
488
what is result of synaptic fatigue
loss of excitability
489
what does synaptic fatigue protect against
excess neuronal activity
490
what is post-tetanic facilitation
enhanced responsiveness following repetitive stimulation
491
what ion causes post-tetanic facilitation
Ca ions in presynaptic termininal
causes more vesicular release of transmitter
492
what is synaptic delay
the process of neurotransmision takes time, from the delay can calculate the number of neurons in a circuit
493
what does electrical stimulation of periaqueductal gray area do
relieves pain
inhibits nociceptive projection neurons in dorsal horn of cord
494
analgesia system diagram
495
what nerve fibers does enkephalin inhibit
type C
type A delta
496
T/f the cortex functions alone
False
Cortex never functions alone, always in association with lower centers
497
What are functions of cortex
Large memory story
Essential for thought processes
Takes information body gains, processes it and gives response for body
498
What’s another name for the soma
Cell body
499
What is the effector part of the neuron
Axon
500
What is the sensory portion of the neuron
Dendrite
501
Which. Channels and ions create an epsp
Cations
Na K Ca
502
What does glutamate do
Opens cation channels
Chief excitatory transmitter in CNS
503
What does GABA do
Opens Cl- channels
Chief inhibitory transmitter in adult CNS
504
Which ions are involved in creating ipsp
K or Cl-
505
What are 4 functions of G protein?
-open channels
-activate enzymes (membrane enzymes)
-activate one or more intracellular enzymes
-activates gene transcription
506
What is the inhibitory transmitter mainly in the cord
Glycine
507
Classes of neuropeptides
Hypothalamic releasing hormones
Pituitary peptides
Peptides that act on gut and brain
Peptides that work on other tissues
508
What sensory receptors are in the epidermis
Free nerve endings
Meissner corpuscle
Merkel cells
509
What sensory neurons are in the dermis
Ruffini corpuscles
510
What sensory neurons are in the subq layer
Pacinian corpuscles
511
Why is there no action potential except in the axon?
No Na channels except in the axon
512
What causes sudden cessation of reverberation?
Fatigue of synaptic junctions
513
What is the mechanism of fatigue
Transmission depletion
Receptor inactivation
Abnormal ion concentration in axon
514
what receptor function is proprioception
muscle spindle
515
what receptor function is touch
merkel
meissner
pacinian
ruffini
516
what are neuronal pools?
groups of neurons with special characteristics of organization
517
Meissner corpuslces location, function, stimuli, adaptation and type
location: nonhair skin close to surface
function: motion detection, grip control
stimuli: skin motion, low frequency vibration
adaptation: rapid adaptation
type: A beta
518
merkel location, function, stimuli, adaptation, type
location: tip of epidermal ridges
function: form and texture perception
stimuli: edges, points, corners, curvature
adaptation: slow
type: A beta
519
Pacinian corpuscle location function stimuli adaptation receptive field and type
location: dermis and deeper tissues
function: perception of distant events through transmitted vibrations
stimuli: vibrations
adaptation: very rapid
receptive field: entire finger or hand
type A beta
520
Ruffini corpuscle location function stimuli adaptation and type
location: dermis
function: tangential force; hand shape; motion detection
stimuli: skin stretch
adaptation: slow
type A beta
521
what type of nerve fibers are myelinated free nerve endings
type A delta
522
What does substance P do
Excited pain fiber nerve ending
523
What does substance P do
Excited pain fiver nerve ending
524
What does substance P do
Excited pain fiver nerve ending
525
Where do paleospinothalmi. Tract fibers terminate
Diffuser in reticular nuclei of medulla pons and mesencephalon
Tectal area of mesencephalon
Periaqueductal gray area
526
What is the mechanism of referred pain
Intermingling of second order neurons in dorsal horn of spinal cord from skin and viscera
527
Muscle spindle axon type
Ia and II
528
Muscle spindle axon type
Ia and II
