HR block 6 part 1 Flashcards
(500 cards)
1
Q
What cortex covers most of the cortical surface?
A
neocortex
2
Q
Which cortex is the most primitive?
A
archicortex
3
Q
What cortex has 3 laminae?
A
archicortex
4
Q
What cortex has 6 laminae?
A
neocortex
5
Q
What cortex has 4 laminae?
A
paleocortex
6
Q
What are stellate cells important for?
A
local circuit processing
7
Q
What do pyramidal cells do?
A
provide output axons
8
Q
Cells above and below each other perpendicular to the pial surface have ___ functional properties.
A
common
9
Q
What layer do thalamic inputs go to?
A
4
10
Q
Where does layer 2 project to?
A
other cortical areas
11
Q
Where does layer 3 project to?
A
opposite hemisphere
12
Q
Where does layer 5 project to?
A
subcortical structures
13
Q
Where does layer 6 project to?
A
feedback to thalamus
14
Q
What is Brodmann’s cytoarchetectonics based on?
A
histological variation in thickness and cell density
15
Q
What is an association cortex?
A
areas that can’t be defined with a simple motor or sensory function
16
Q
What are association fiber bundles?
A
connect cells within the same hemisphere
17
Q
What does the superior longitudinal fasciculus connect?
A
fronto - parieto - occipital
18
Q
What does the uncinate fasciculus connect?
A
temporo-frontal
19
Q
What does the inferior longitudinal fasciculus connect?
A
occipito-temporal
20
Q
What fibers connect one hemisphere to another?
A
commissural fibers
21
Q
What is the major commissural fiber?
A
corpus callosum
22
Q
What does the anterior commissure connect?
A
opposite temporal lobes
23
Q
What does the posterior commissure connect?
A
opposite pretectal areas
24
Q
What fibers connect different areas of the brain?
A
projection bundles
25
What is the largest projection bundle?
internal capsule (thalamus-cortex cortex-thalamus cortex-brainstem/spinal cord)
26
What does the fornix connect?
hippocampus to mammilary body in the diencephalon
27
What does the hippocampus do?
transfer memory to long term storagespatial orientation
28
Which lobe is the hippocampus in?
medial temporal lobe
29
What kind of cortex is the hippocampus?
archicortex
30
Where is the diencephalon?
between brainstem and telencephalon
31
What does the thalamus do?
takes inputs to the cortex
32
What input that goes to the cortex bypasses the thalamus?
olfactory input
33
What bounds the thalamus laterally?
internal capsule
34
What are the two halves of the thalamus separated by?
3rd ventricle
35
Where does the thalamic lateral geniculate nucleus project to?
visual cortex
36
Where does the medial geniculate nucleus project to?
auditory cortex
37
Where does the thalamic ventral-posterior nuclei project to?
somato-sensory
38
Where does the thalamic ventral anterior-ventral lateral nuclei project to?
premotor and motor cortex
39
Where does the thalamic anterior nucleus project to?
cingulate gyrus
40
Where does the thalamic mediodorsal nucleus project to?
frontal association cortex
41
Where does the thalamic lateral posterior pulvinar nuclei project to?
parietaloccipitaltemporal association cortex
42
What property of thalamic nuclei provides the EEF oscillating circuit?
each thalamic nuclei receives feedback from the same cortical area it projects to
43
What do reticular nuclei contain?
inhibitory interneurons that adjust thalamic signaling
44
Where is CNII?
ventral diencephalon
45
Where is CNIII
ventral midbrain
46
Where is CN IV?
dorsal midbrain
47
Where is CN V?
over ventrolateral pons
48
Where is CN VI?
ventral medulla
49
Where is CN VII?
lateroventral medulla
50
Where is CN VIII?
lateral medulla
51
Where is CN IX?
lateral medulla
52
Where is CN X?
lateral medulla
53
Where is CN XI?
lateral surface of cervical spinal cord
54
Where is CN XII?
ventral caudal medulla
55
What is the nuclei for CNI?
anterior olfactory nucleus
56
What is the nuclei for CN II?
lateral geniculate nucleus
57
What is the nucleus for CN III?
oculomotor nucleusedinger-westphal nucleus
58
What is the nuclei for CN IV?
trochlear nucleus
59
What is the nuclei for CN V?
principal sensory trigeminal nucleusspinal trigeminal nucleusmesencephalc trigeminal nucleustrigeminal motor nucleus
60
What is the nuclei for CN VI?
abducens nucleus
61
What are the 3 nuclei for CN VII?
facial nucleussolitary nucleussuperior salivary nucleus
62
What is the nuclei for CN VIII?
vestibular nucleicochlear nuclei
63
What are the 3 nuclei for CN IX?
nucleus ambiguusinferior salivary nucleus solitary nucleus
64
What are the 3 nuclei for CN X?
nucleus ambiguusdorsal motor vagal nucleussolitary nucleus
65
What is the nucleus for CN XI?
nucleus ambiguusspinal accessory nucleus
66
What is the nucleus for CN XII?
hypoglossal nucleus
67
Which is the CNV nuclei?
red
68
Which is the CN III nuclei?
top yellow
69
Which is the CN IV nuclei?
yellow second from the top
70
Which is the CN VI nuclei?
yellow in middle
71
Which is the CN X nuclei?
purple at bottom
72
Which is the Edinger-Westphal nuclei?
purple at top
73
Which is the CNVIII nuclei?
green
74
Which is the nucleus solitarius?
blue at bottom
75
In the neural tube, alar (dorsal) plate cells give rise to ___ neurons.
sensory
76
In the neural tube, basal palte cells (ventral) give rise to ___ neurons.
motor
77
CN nuclei are located from medial to lateral relative to functional role:
somatic motorvisceral motorbranchial motorvisceral sensorygeneral somatic sensoryspecial somatic sensory
78
Which CN nuclei are somatic motor?
oculomotortrochlearabducenshypoglossal
79
Which CN nuclei are branchial motor?
trigeminal motorfacialnucleus ambiguusspinal accessory
80
Which CN nuclei are visceral motor?
edinger-westphalsuperior/inferior salivatorydorsal motor nucleus of vagusnucleus ambiguus
81
Which CN nuclei are general sensory?
mesencephalicprincipalspinal
82
Which CN nuclei are special sensory?
vestibularcochlear
83
Which CN nuclei is visceral sensory?
nucleus of the solitary tract
84
Which CN are only sensory?
IIIVIII
85
Which CN are only motor?
IIIIVVIXIXII
86
What does CNI do?
sense of smell
87
What does CNII do?
vision
88
What does CNIII do?
eye movementspapillary constriction and accommodationmuscles of eyelid
89
What does CNIV do?
eye movements
90
What does CNV do?
somatic sensation fromf ace, mouth, cornea, mastication muscles
91
What does CNVI do?
eye movements
92
What does CNVII do?
controls facial expressiontaste from anterior tonguelacrimal and salivary glands
93
What does CN VIII do?
hearingsense of balance
94
What does CN IX do?
sensation from pharynxtaste from posterior tonguecarotid baroreceptors
95
What does CN X do?
autonomic functions of gutsensation from pharynxmuscles of vocal cordsswallowing
96
What does CN XI do?
shoulder and neck muscles
97
What does CNXII do?
movements of tongue
98
What is the clinical test for CNI?
test smell with standard odor
99
What is the clinical test for CNII?
measure acuity and integrity of visual field
100
What is the clinical test for CNIII?
test eye movementlook for ptosispupillary dilation
101
What is the clinical test for CNIV?
can't look down when eye abducted
102
What is the clinical test for CNV?
test sensation on facepalpate masseter muscles and temporal muscle
103
What is the clinical test for CNVI?
can't look laterally
104
What is the clinical test for CNVII?
Test facial expression plus taste on anterior tongue
105
What is the clinical test for CNVIII?
test audition with tuning forkvestibular function with caloric test
106
What is the clinical test for CNIX?
test swallowingpharyngeal gag reflex
107
What is the clinical test for CNX
test swallowingpharyngeal gag reflexhoarseness
108
What is the clinical test for CNXI?
test sternocleidomastoid and trapezius M
109
What is the clinical test for CNXII?
test deviation of tongue during protrusion
110
What is the prominent CN nuclei at the caudal medulla?
spinal nucleus of CNV
111
What neurologic symptoms does lesion to nucleus ambiguous present?
difficult swallowinghoarse voice
112
What nuclei are present at the rostral medulla?
cochlearmedial and lateral vestibularsolitary tract
113
What two prominent motor nuclei are at the caudal pons?
abducensfacial
114
What CN nuclei is present at the middle pons?
CN V motor and sensory
115
What CN nuclei are present at the midbrain level?
trochlearoculomotorEdinger-Westphal
116
Where do mechanoreceptors go after entering the spinal cord?
layer 4 interneurons -> local reflexipsilateral dorsal column to ascend
117
What structure do DCL second order axons rise in?
medial lemniscus
118
What 3 sensations are transmitted via DCL?
touchpressure proprioception
119
DCL has ___ lateral inhibition.
strong
120
In the dorsal column, lower limb sensations rise medial/lateral.
medial
121
What vertebral level is the dorsal nucleus of Clarke?
thoracic
122
Where do dorsal nuclei of Clark neurons go?
ipsilaterally to the cerebellum via the dorsal spinocerebellar tract to inferior cerebellar peduncle
123
What does the cuneate fasciculus carry?
DCL from arm
124
Where do DCL axons first synapse?
dorsal column nuclei at caudal medulla
125
What DCL fibers decussate at the caudal medulla level?
arcuate fibers to the medial lemniscus
126
At the medulla level medial lemiscus carries mechanoceptive information from which side of the body?
contralateral
127
At the level of the pons, what does the medial lemniscus arm/feet orientation look like?
feet lateralarm medial
128
How does mechanoreceptor sensation frmo the head enter the brain?
trigeminal ganglion to ponssynapse in principal nucleus of trigeminal complexcross over to join medial lemniscus
129
Where is the second DCL synpase?
caudal thalamus at ventral posterior nuclei
130
Where do DCL axons go after the thalamus?
posterior limb of the internal capsule to post-central gyrus
131
What are the 3 main Brodman's areas in the post-central gyrus?
3a - muscle proprioceptors3b - skin1 - rapid receptors2 - deep tissue mechanoreceptors
132
Sacral axons enter the anterolateral tract at this position.
lateral
133
What 2 receptors enter the dorsal horn and ascend or descend a level?
nociceptorsthermoreceptors
134
Where is the first ALS synapse?
dorsal horn
135
How does head nociception enter the ALS?
enter at ponstravel to caudal medulla ins pinal trigeminal tractsynapse and cross over to contralateral ALS
136
C fibers compose what part of the ALS?
paleospinothalamicdeep, aching, poorly localized pain
137
What fibers make up the neospinothalamic ALS?
A delta
138
What part of the brain processes the emotional aspect of pain?
anterior cingulate gyrus
139
What does the spinoreticular pathway do?
ALS component that ends in brainstem reticular centers to mediate reflex response to pain
140
What nucleus provides analgesia?
periaqueductal grey
141
Descending pathway for analgesia starts at the PAG and goes to?
nucleus raphe in the medulla
142
What does nucleus raphe magnus do?
via dorsolateral fasciculussynapse at dorsal horn to activate enkephalin interneurons
143
What is the major projection pathway from M1?
corticospinal (pyramidal)
144
pyramidal axon breakdown: _% from M1_% rostral to M1_% from S1
303040
145
How do the pyramidal tract axons reach the thalamus?
posterior limb of internal capsule
146
How does the corticospinal tract go through the midbrain?
middle 1/3 of the cerebral peduncle
147
What tract innervates the cranial motor nuclei?
corticobulbar
148
Where is the red nuclei?
midbrain
149
The red nuclei receives synaptic input from M1 and gives rise to __?
rubrospinal projections
150
Most red nuclei axons end __.
cervical levels
151
Most corticospinal axons synapse at __.
Rexed's layer interneurons (VI - VIII)
152
Corticospinal axons usually __ flexors.
facilitate
153
What is the orientation of CST axons in the internal capsule from anterior to posterior?
face arm trunk leg
154
What % of CST axons decussate at the medulla?
90%
155
What do rubrospinal neurons regulate?
rate of force developmentspeed of movement
156
Where does somatosensory feedback to M1 neurons come from?
S1 cortex and ventral posterolateral nucleus
157
What do lesions to SMA cause?
basal ganglia input lackingcan't use both hands together
158
What atrophies in Pick's disease?
frontotemporal lobes
159
What degenerates in ALS?
alpha motorneurons
160
List 3 symptoms of upper motor neuron injury:
weaknesshyperactive deep reflexBabinski's
161
List 3 symptoms of lower motor neuron injury:
paralysisdecreased superficial and deep reflexsevere muscle atrophy
162
Define spasticity:
increased tone and stretch reflexes
163
What motor neurons does the reticulospinal tracts affect?
gammaextensor inhibition
164
What function does the medullary reticular formation have?
inhibit extensors
165
What function does the pontine reticular formation have?
facilitates extensors
166
What causes spastic paralysis in upper motor neuron lesions?
extensor facilitationhigh gamme motor neuron input
167
In spasticity, resistance is greatest for what muscles?
antigravity muscles
168
What is Babinski's sign?
After a strong stroke to the plantar surface of the foot, dorsiflexing.
169
Where do rubrospinal axons originate?
red nucleus
170
Where does the reticulospinal pathway originate?
reticular formation
171
Where does the tectospinal pathway originate?
superior colliculi
172
What does the vestibule detect?
linear accelerations
173
What do the semicircular canals detect?
angular acceleration
174
What determines hair cell depolarization?
stereocilia bending towards kinocilia
175
How are semicircular canals stimulated?
hair cells in the ampulla are bent by fluid movement
176
In the utricle, kinocilia are directed __ the striola.
towards
177
In the saccula, kinocilia are directed __ the striola.
away from
178
Which otolith organ senses horizontal movement?
utricle
179
Which otolith organ senses vertical movement?
saccule
180
What are the CaCO3 crystals in the otolithic membrane?
otoconia
181
What does the lateral vestibulospinal tract do?
changes muscle tone in response to gravity
182
What does the medial vestibulospinal tract do?
gaze
183
Where does the lateral vestibulospinal tract receive input from?
utricle and saccule
184
Where does the medial vestibulospinal tract receive input frmo?
semicircular canals
185
Where does the medial vestibulospinal tract end?
cervical muscles
186
Where does the lateral vestibulospinal tract end?
postural muscles
187
What causes Meniere's disease?
liquid accumulation in inner ear
188
What are the mini-gyri on the cerebellum called?
folia
189
What structure makes up the midline of the cerebellum?
vermis
190
What are the two major fissures of the cerebellum?
primarydorsal posterolateral groove
191
What is the deep groove on the inferior cerebellum?
vallecular cerebelli
192
What is the largest lobe of the cerebellum?
posterior
193
What does the superior cerebellar peduncle contain?
cerebellar efferents to brainstem (especially red nucleus)
194
Where do contralateral pontine axons enter the cerebellum?
middle cerebellar peduncle
195
What does the inferior cerebellar peduncle contain?
cerebellar afferents from the spinal cord and lower brain stem
196
Name the deep cerebellar nuclei from lateral to medial:
dentateemboliform (interposed)globose (interposed)fastigial
197
Where does the fastigial nucleus receive inputs from?
vermis
198
Where does the interposed nuclei receive inputs from?
paravermal zone
199
Where does the dentate nucleus receive inputs from?
cerebellar hemispheres
200
List the parts of the vestibulocerebellar strip.
cortex of the vermisflocculonodular lobefastigial nucleus
201
List the parts of the spinocerebellar strip.
paravermal cortexassociated interposed nucleus
202
List the parts of the pontocerebellar cortex.
cortex of hemisphereslateral stripdentate nucleus
203
What nuclei goes to the vestibulocerebellum?
vestibular nuclei
204
What nerve goes to the spinocerebellum?
trigeminal cranial nerve
205
What does the vestibulocerebellum control?
posturebalance
206
What does the spinocerebellum control?
movement errors
207
What does the pontocerebellum control?
limb and hand movements
208
What layer of the cerebellar cortex is the source of all efferents?
purkinje cell layer
209
What fibers send input to the granular layers?
mossy
210
Which cerebellar layer receives input from the inferior olivary complex?
Purinkje layer
211
What cells do mossy fibers synapse on?
glomeruli
212
What cells in the cerebellar cortex send excitatory signals?
granule
213
What cells inhibit the purkinje cells?
basket and stellate cells in the molecular layer
214
What do Golgi cells do?
suppress the excitation of granule cells
215
What is cerebellar spatial focus?
lateral inhibition of Purkinje cells by basket cells
216
What is cerebellar phasic quality?
inhibition by stellate cells of recently activated Purkinje cells
217
What is cerebellar temporal resolution?
granule cell inhibition by Golgi cells
218
Purkinje cells can remember that thye have been excited by __.
climbing fibers from the inferior olivary nucleus
219
What NTS do Purkinje cells use?
GABA
220
Where do all cerebellar inputs converge?
at the cortexaxons usually give off collaterals to deep cerebellar nuclei on the way
221
What do deep cerebellar nuclei compare?
cortial outputs and cerebellar inputs
222
Are cerebellar signals homo or contralateral?
homo
223
What nuclei does the flocculonodular lobe receive inputs from?
vestibular nucleivestibular ganglion
224
What tracts directly provide input to the spinocerebellum?
dorsal and venrtal spinocerebellum
225
What nuclei sends axons into the dorsal spinocerebellar tract?
Clark's nucleus (dorsalis)
226
The dorsal spinocerebellar tract enters the cerebellum via?
inferior cerebellar peduncles as mossy fibers
227
External cuneate nucleus axons travel through what tract?
cuneocerebellar tract
228
What is the upper limb equivalent of dorsal nucleus of Clark?
external cuneate nucleus
229
What tract does the trigeminocerebellar tract enter the cerebelum through?
inferior cerebellar peduncle
230
What tract does the tecctocerebellar tract pass through?
superior cerebellar peduncle
231
Pontine nuclei relay signals to the cerebellum from where?
ipsilateral cerebral cortex
232
Where do fastigial nuclei send outputs to?
vestibular and reticular nuclei
233
Where do interposed and dentate nuclei send axons?
contralateral red nucleus and thalamus
234
Which peduncle decussates in the brainstem?
superior
235
What does the superior cerebellar A supply?
cortex and white matterdeep cerebellar nuclei
236
Where does AICA supply?
ventral cerebellum and dentate nucleus
237
Where does PICA supply?
inferior cerebellumchoroid plexus of 4th ventricle
238
What is caudal vermis lesion that causes unsteadingess and swaying (drunken sailor's gait)?
postural ataxia
239
What is lesions of the anterior lobe causing an antero-posterior sway?
body sway
240
What is lateral lesions invovling the pontocerebellum that causes poor motor programming?
limb ataxia
241
What is bilateral cerebellar lesions involving the dentate nucleus causing sequential movements?
dysdiadochokinesia
242
What does cerebellar nystagmus cause?
periodic alternating nystagmus caused by nodulus lesions
243
What causes loss of visual pursuit?
flocculus lesions
244
What is the midbrain-pons junction called?
isthmus
245
What is a chronic autoimmune disease characterized by AChR destruction
Myasthenia Gravis
246
What is the major excitatory neurotransmitter?
glutamate
247
What %age of CNS neurons use glutamate?
50%
248
What does glutamate overload cause?
excitotoxicityALSstrokedrug abuseepilepsy
249
What %age of CNS neurons release GABA?
33%
250
What NTS causes smooth muscle contraction?
5HT
251
What aa is 5HT produced from?
W
252
What is the principal nuclei for 5HT?
raphe nuclei
253
What is the main NTS involved with movement?
dopamine
254
What aa is dopamine synthesized from?
Y
255
What is the main nuclei involved in dopamine?
substantia nigra
256
What is the principal center for noradrenergic neurons?
locus coeruleuscaudal raphe nuclei
257
NE/Epi, which comes first?
NE
258
What 5 components does the basal ganglia include?
caudateputamenglobus pallidussubthelamic nucleussubstantia nigra
259
What 2 components does the striatum include?
caudateputamen
260
What are the 3 major afferents to the striatum?
dopaminergic from substantia nigraglutamatergic from cortexglutamatergic from intralaminar thalamic nuclei
261
What are the 3 major efferents from the striatal medium spiny neurons?
globus pallidus internalglobus pallidus externalreticular substantia nigra
262
What do GPi/e neurons secrete?
GABA
263
Where do GPe efferents project?
subthalamic nuclei
264
Where do GPi and SNpr efferents project?
VA VL thalamic nuclei
265
Which basal ganglia neurons are tonically active?
GPi/SNpr GABA neurons
266
What brain regions tonically inhibit the VA VL thalamic neurons?
GPiSNpr
267
Describe the direct pathway in basal ganglia signaling.
substantia nigra pars compacta (dopamine) + cerebral cortex (glutamate)increase caudate/putamendecrease globus pallidus internalincrease VA VLincrease frontal cortex
268
Describe the indirect pathway of basal ganglia signaling.
substantia nigra pars compacta (dopamine) + cerebral cortex (glutamate)increase caudate/putamendecrease globus pallidus externalincrease subthalamic nucleiincrease globus pallidus internaldecrease VA/VLdecrease cortex
269
The basal ganglia direct pathway outputs to ___ functional units.
specific(indirect is broad)
270
What parts of the cerebral cortex do not innervate the basal ganglia?
visual and auditory
271
How does Parkinson's affect basal ganglia signaling?
decreased substantia nigra signaling to decrease excitation
272
What does Huntington's degenerate?
spiny striatal neurons in the indirect striatopalidal pathway
273
How does Huntington's affect basal ganglia signaling?
caudate/putamen inhibition of the globus pallidus external is lost and excitation of the cortex is increased
274
What does pitch correspond to?
frequency
275
What does loudness correspond to?
amplitude
276
What is the equation for sound pressure levels?
dB = 20 * log (P_measured/P_reference)
277
What does decibels measure?
sound energy
278
Loudness doubles for every _ dB increase in energy.
10 dB
279
What structures make up the outer ear?
concha (pinna or auricle)
280
What part of the ear canal is susceptible to pain?
innermost bony canal
281
The pinna emphasizes sound pressure of what freq?
2 kHz
282
What are the two ways the middle ear concentrates sound pressure in air to the cochlear fluids?
ear drum area is 18x of the stapes footplatemiddle ear ossicles act as a lever system
283
How much energy do you end up losing in the air to cochlear fluid transition?
50%
284
What part of the ear is most susceptible to ear infections?
middle ear cavity
285
What drains the middle ear cavity?
eustachian tube
286
Why are the floor bones of the middle ear cavity pneumatized?
increase cavity volume to enhance low frequency sounds
287
What attaches the malleus to the eardrum?
manubrium
288
What holds the stapes in place?
annular ligament of the oval window
289
What does the tensor tympani do?
Attaches to the malleus and cavity wall to pull the eardrum in
290
What does the stapedius do?
Attaches to stapes and cavity wall to rotate the stapes and stiffen the ossicles so low frequency sounds are not transferred
291
What A/V combo runs near the middle ear cavity?
internal carotid Ainternal jugular V
292
Where does the eustachian tube go?
middle ear cavity to back of nasopharynx
293
What 2 parts of the cochlea are filled with perilymph?
scala vestibuli and tympani
294
What part of the cochlea is filled with endolymph?
scala media
295
Where does sound energy input into the cochlea?
oval window (part of scala vestibuli)
296
What connects the scala vestibuli and tympani?
helicotrema
297
Where does sound energy exit the cochlea?
via scala tympani - round window
298
What is the composition of perilymph?
ECF-likehigh Nalow K0 mV
299
What is the composition of endolymph?
ICF-likehigh Klow Na+80 mV
300
How is endolymph composition maintained?
active transport by stria vascularis
301
What drugs can be ototoxic due to their effect on the stria vascularis?
aminoglycoside antibioticsdiuretics
302
Hair cells lie on what border?
scala media and tympanicochlear duct
303
Which hair cells are closer to the internal auditory meatus?
inner
304
Which hair cells are covered with afferents?
inner hair cells
305
Which hair cells are covered with efferents?
outer hair cells
306
How many rows of inner/outer hair cells?
3-Jan
307
Where do the stereocilia of the hair cells lie?
in the scala media (endolymph)
308
What cels are responsible for transduction of basilar membrane vibrations?
inner hair cells
309
What ion enters inner hair cells to cause signal tranduction?
K
310
What intracellular inner hair cell ion changes in response to signal transduction?
Ca
311
What produces pitch perception at low frequencies?
place (basilar membrane)timing (periodicity pitch)
312
Each inner hair cell is innervated by how many auditory nerves?
20
313
What is the afferent fiber response to tone burst?
rapid adaptation to steady state
314
Define characteristic frequency:
Each auditory nerve fiber is tuned to a best frequency
315
How does auditory two tone suppression work?
biomechanical changes in cochlear duct to sharpen the acoustic response
316
What do the outer hair cells do?
receive CNS efferents to modify cochlear tuning (stiffness)
317
Each contralateral brainstem efferent can innervate __ outer hair cells.
20
318
Where do outer hair cell efferents originate?
contralateral medial superior olivary nuclei
319
The traveling wave of vibration traves frmo the __ to the __ of the cochlea.
base to apex
320
The base receives what type of frequencies?
high
321
What part of the basilar membrane receives low frequency waves?
apex
322
What does the weber test tell you?
separatesconduction deafness frmo sensorineural deafness
323
What can cause hearing conductive loss?
plugged outer earinfected middle earperforated ear drumdisarticulated ossicular chainotosclreosis
324
What side do ascending auditory pathways take?
contralateral
325
Where is the first complex where inputs from both ears converge?
superior olivary complex
326
What nerves does the medial SOC receive?
crossed efferents to outer hair cells
327
What nerves does the lateral SOC receive?
uncrossed efferents to the inner hair cells
328
What nerves does the labyrinthine A run with?
7 and 8
329
The facial nerve runs along the medal middle ear cavity to emerge at what foramen?
stylomastoid
330
The inferior colliculus is the brainstem equivalent to what?
auditory cortex
331
What part of the thalamus projects to the auditory cortex?
medial geniculate body
332
What fissure contains the auditory cortex?
sylvian fissure
333
What causes presbycusis?
stria (cochlear power supply) atrophy
334
Axons from olfactory receptors project directly to __.
olfactory bulb
335
What is unique about olfactory receptors
regenerate from basal neuroblasts
336
What part of the olfactory neuron has to be stimulated by odorants?
cilia
337
What controls olfactory neuron depolarization amount?
odorant concentration
338
What do olfactory binding proteins do?
bind to and help transport odorants from air to cilia
339
What downstream signaling is activated by odorant binding?
GPCR -> cAMP -> Na channels
340
What cells do olfactory afferents first synapse on?
mitral cells
341
What cells do olfactory neurons synapse on second?
olfactory areas of temporal and frontal lobes
342
What do periglomerular interneurons do?
lateral inhibition of odor
343
What part of the temporal lobe do olfactory tracts go to?
ventromedial surface
344
What makes up the primary olfactory area?
limen insulaeentorhinal areauncus
345
The activity in one olfactory bulb affects the contralateral bulb through what?
anterior commissure
346
What does the lateral posterior quadrant of the orbitofrontal lobe control?
odor recognition
347
What tract goes b/w entorhinal area of temporal lobe to lateral posterior quadrant of the orbitofrontal lobe?
uncinate fasciculus
348
What is loss of smell called?
anosmia
349
What neural tissue is the pituitary gland attached to?
hypothalamus
350
What do medial hypothalamic nuclei control?
pituitary secretions
351
The lateral hypothalamic area makes up what neural structure?
medifal forebrain bundle
352
The median forebrain bundle connects the basal forebrain with __.
reticular formation of the midbrain tegmentum
353
What does the stria terminalis connect?
amyygdala and medial preoptic area
354
What connects the amygdala with the lateral hypothalamus?
ventral amygdalofugal pathway
355
Where does the mammillothalamic tract go?
hypothalamus
356
What does the stria medullaris connect?
lateral preoptic and hypothalamus to habenular nuclei
357
What output goes from the hypothalamus to the paramedian tegmentum?
mammillotegmental tract
358
What 2 important structures are in the rostral hypothalamus?
preoptic areasuprachiasmatic nucleus
359
What does the preoptic area secrete?
regulators of gonadotrophin secretion by anterior pituitary
360
What does the suprachiasmatic nucleus do?
input frmo retinal axons
361
What part of the brain controls the circadian clock?
suprachiasmatic nuclei
362
What part of the brain controls heat response?
anterior hypothalamus
363
What part of the brain controls cold response?
posterior hypothalamus
364
What are the two magnocellular secretory nuclei?
paraventricular and supraoptic
365
Where do PVN axons end?
posterior pituitary capillaries
366
PVN and SON secrete what 2 molecules?
oxytocinvasopressin
367
Which part of the pituitary secreted regulatory peptides into a capillary plexus?
anterior
368
What 2 important structures are found in the mid caudal hypothalamus?
ventromedial/lateral nucleiPVN and SON
369
Destroying the ventromedial hypothalamus causes __.
obesity
370
Destryoing the lateral hypothalamus causes __.
starvation
371
What are short term cues for feeding?
glc levels that regulate meal size
372
What are long term cues for feeding?
regulate overall body weight through leptin (adipocytes)
373
Leptin and insulin affect what part of the brain?
ARC
374
list the 4 orexigenic peptides:
ghrelinneuropeptide YAgRPorexin A and B
375
List the 8 anorexigeneic peptides:
leptinCCKinsulincytokinespeptide YYamylinPomCCART
376
Is POMC orexigenic or anorexigenic?
anorexigenic
377
Is ghrelin orexigenic or anorexigenic?
orexigenic
378
How do orexigenic peptides affect feeding?
increase
379
What important structures are in the caudal hypothalamus?
mammillary bodies
380
What connects the cingulate gyrus with the hippocampus?
cingulum bundle
381
How does histamine affect the brain?
promotes behavioral arousal
382
What is a common way the hypothalamus is damaged?
dorsal expansion of a pituitary tumor
383
What part of the tongue is most sensitive to sweet?
tip
384
What part of the tongue is most sensitive to bitter?
rear
385
What part of the tongue is most sensitive to salt and sour?
lateral surface
386
Other than the tongue, what 4 other places are taste buds found?
palategingiviasoft palatepharynx
387
What CN provides afferents to the anterior tongue?
VII
388
What CN provides afferents for the posterior tongue?
IX
389
What CN provides afferents for the epiglottis?
X
390
What taste buds are found anteriorly?
fungiform
391
What taste buds are found posteriorly?
circumvillate/foliate
392
Are taste buds selective?
no
393
Are olfactory receptors selective?
yes
394
What molecule entering the cell induces taste transduction?
K
395
What tastes are transduced via GPCR?
sweet, aa, bitter
396
What tastes are transduced via ion channel?
saltsour
397
What nuclei recevies taste afferents?
solitary
398
What part of the solitary nucleus receives taste afferents?
rostral
399
What 3 locations do axons from the rostral solitary nucleus go?
local connections to brainstem reticular formationparvicellular portion of the ventral posteromedial nucleus of thalamus (VPMpc)parabrachial nucleus of midbrain
400
What CN rech the caudal solitary nucleus?
IX and X
401
What nucleus relates to the conscious perception of taste?
ventral posteromedial nucleus (VPMpc)
402
What nucleus relates to the affective and behavioral response to taste?
parabrachial nucleus of midbrain
403
What are the 3 eyeball ayers from out to in?
fibrous layeruvearetina
404
What composes the fibrous layer of the eyeball?
schleracornea
405
What makes up the uvea of the eyeball?
choroidciliary bodyiris
406
Which eyeball chamber is between the cornea and iris?
anterior
407
What spaces is b/w the iris and lens?
posterior chamber
408
What makes up the vitreous chamber of the eyeball?
b/w lens and retina
409
What produces aqueous humor?
ciliary body
410
What drain aqueous fluid from the anterior eyeball chamber?
Schlemm canals
411
What causes glaucoma?
impeded outflow from the anterior chamber of the eyeball
412
Is the viterous humor replaced?
no, it is stagnant
413
What is the eyeball space called where axons leave to form the optic nerve
optic disc
414
The optic N sheath is continuous with __ space of the brain
subarachnoid
415
Where is the fovea centralis?
optical center of eye
416
What part of the eyeball has the most acute vision?
fovea centralis
417
What is the refractive power of the eye?
60-72 diopters
418
At what part of the eye is the greatest amount of refraction?
air to cornea
419
As objects move closer to the eye, the lens increases its power. This process is called __.
accommodation
420
Accommodation requires what muscle?
ciliary M
421
What is the most common visual defect?
loss of accommodation
422
What is the loss of near vision called?
presbyopia
423
What is emmetropia?
normal vision
424
What is hypermetropia?
farsightedness (near objects are blurry because the eye has too little power or is too short)
425
What is myopia?
nearsightedness (distant objects are blurry because the eye has too much power or is too long)
426
What is an astigmatism?
power of eye is not the same for all axes
427
What is the first layer of the retina that light passes?
nerve fiber layer
428
What is the last retina layer that light hits?
photoreceptor
429
What photoreceptors see colors?
cones
430
What photoreceptors see dim light?
rods
431
What are the two layers of synaptic transmission in the retina?
outer and inner plexiform
432
What cells synapse at the outer plexiform layer of the retina?
photoreceptors with bipolar and horizontal cells
433
What cells synapse at the inner plexiform layer?
bipolar cells with ganglion and amacrine cells
434
What retinal cells use action potentials?
amacrineganglion
435
What is the light sensitive molecule in photorecptors?
retinal
436
What is the key event for visual transduction?
11-cis-retinal absorbs photon and isomerizes to all-trans form
437
What part of the retina have cones?
fovea
438
What is the purpose of having 3 types of cone cells?
each absorbs a different wavelength of light
439
What is wrong with dichromats?
missing one whole group of photopigment
440
Which sex is more likely to be dichromat?
male
441
How much does the pupil diameter change to adjust light entry by 16 fold?
2-8 mm
442
How many rod cells converge on each bipolar cell?
many
443
How many cones converge on a cone cell?
one
444
What do horizontal cells do?
emphasize response to contrast in the visual scene
445
What do amacrine cells do?
emphasize response to movement
446
The visual field extends __ degrees nasally
60
447
The visual field extends __ degrees temporally
100
448
The visual field extends __ degrees above
60
449
The visual field extends __ degrees below
75
450
The macula corresponds to central __ degrees
13
451
The fovea corresponds to the central __ degrees
3
452
fibers from the __ half of the retina cross at the chiasm
nasal
453
The left optic tract comes from what part of the retina?
left half of each retina (R visual field)
454
The R half of the CNS receives activity from the __ visual field
L
455
Axons from the ipsilateral retina project to what layers of the LGN?
2 3 5
456
Axons from the contralateral retina project to what layers?
1 4 6
457
Which LGN layers receive inputs from Y type ganglion cells?
magnocellular layers (1, 2)
458
Which LGN layers receive inputs from X type ganglion cells?
parvicellular layer (3 - 6)
459
How to go from LGN to occipital lobe?
LGN -> optic radiations -> retrolenticular part of internal capsule -> occipital lobe
460
Axons from the peripheral retina end at what part of the visual cortex?
anterior
461
Axons from the foveal retina end at what part of the visual cortex?
posterior
462
Axons from the upper retinal field synapse at what part of the visual cortex?
above calacrine fissure
463
Axons from the lower retinal field synapse at what part of the visual cortex?`
below the calcarine fissure
464
LGN input goes to what layer of the visual cortex?
layer 4
465
What layer of the visual cortex sends axons back to LGN?
6
466
What layer of the visual cortex goes to the superior colliculus?
5
467
Where do layers 1 and 2 of the visual cortex go?
cortico-cortical connections
468
What cells in the visual cortex respond to linear stimulus?
simple cells
469
What does the dorsal stream communicate?
where pathwaymotion, representation of object locations, control of eye and arms
470
What does the ventral stream communicate?
what pathwayform recognition and object representation
471
What is stereopsis?
depth perception
472
What are binocular depth cells stimulated by?
objects at different distances
473
Loss of accommodation for near vision with age is due to:
decrease in elasticity of crystalline lens
474
Homonymous hemianopsia is caused by a lesion at
anterior portion of one optic tract
475
Which ganglion cell is most responsible for pattern recognition and high visual acuity?
x cells
476
Rods have a __ content of photopigment compared to cones
higher
477
What photoreceptors work better in dim light?
rods
478
After light hits photoreceptors, how does it get to optic N?
bipolar cells to ganglion cells
479
Saccadic Movements are used for ______ types of movements
Fast Ballistic Movements (Target Location)
480
This type of eye motion is used to track or follow a moving object
Smooth Pursuit Movements
481
Latent Period for saccade (time) ? What occurs during this time
200 msec-- computation of direction and distance for saccade
482
Eye movement when both eyes move in same direction
Conjugate
483
Eye movement when eyes move nasally
Convergence
484
Eyes both move temporally
divergence
485
These two movements are used to stabilize the eyes relative to external world thus compensating for head movements
vestibulo-ocular and optokinetic
486
Reflex responses that prevent visual images from slipping as head position changes
vestibulo-optic and optokinetic
487
CN III nucleus arises in ___________ and axons exit through _________
dorsomedial tegmentum (midbrain) ----- interpeduncular fossa
488
CN III remain ipsilateral or contralateral to innervate its four muscles
Ipsilateral
489
CN IV originates in ______ and its axons exit ______
dorsomedial tegmentum (caudal midbrain) ---------- caudal to inferior colliculus
490
CN IV travels (ipsilateral or contralateral ) to innervate ______ muscle
Contralateral ------ Superior Oblique
491
CN VI nucleus is in ________ and its axons exit ________
dorsomedial tegmentum (pons) ------- pontomedullary junction
492
CN VI run ipsilateral or contralateral ? Muscle it innervates?
ipsilateral ---- lateral rectus
493
Interconnect all of occulomotor nuclei
Medial Longitudinal Fasiculus
494
CN III Palsy displays as :
affected eye moving down and outpupil is dilatedPtosis (levator Palpebrae not functioning) Diplopia (double vision)
495
Causes of CN IIII Palsy
Diabetic NeuropathyHypertensionHead TraumaAneurysm
496
CN IV Palsy Symptoms
Head tilted away from affected sideExtorsion of eye (difficult to see)
497
CN VI Palsy Symptoms
Affected eye cannot abductSlight head tilt toward affected side
498
Nerve fibers involved in gaze towards left side
(R) Superior Colliculus --Contralateral- PPRF (L) --IPSILATERAL-- (L) Abducens Nuclei --- (1) Ipsilateral to (L)Lateral Rectus/// (2) Contralateral (R) MLF to (R) Occulomotor Nuclei -- R. Medial Rectus
499
Lesion to R. abducens nerve-- Effect on L/R gaze
Inability for R. eye to look rightLeft Gaze unaffected
500
Lesion to R. Abducens Nucleus-- L/R gaze effect?
Normal Gaze to LeftNeither eye is able to look to right
