neuro revisions Flashcards
(136 cards)
1
Q
how much of the brain is white matter vs grey matter?
A
grey - 40%
white - 60%
2
Q
what does the parietal lobe do?
A
processing sensory info
understanding speech
3
Q
what does the occipital lobe do?
A
processes visual info
4
Q
what does the front lobe do?
A
thinking cap
decision making
planning
movement
5
Q
what does the temporal lobe do?
A
hearing
memory
language
vestibular/balance
6
Q
what does the insular cortex do?
A
located deep in lateral fissure
visceral and autonomic functions
sense of taste
7
Q
what does the limbic cortex do?
A
emotions and memories
8
Q
what are the brodman’s numbers for the primary somatosensory area?
A
3, 1, 2
9
Q
what is the somatosensory area responsible for?
A
PRI: size/shape/texture
in central sulcus
SEC: stereognosis/memory of tactile and spatial environment
in parietal lobe
10
Q
lesions of the somatosensory cortex
A
PRI: loss of tactile localization/proprioception
SEC: astereognosis
11
Q
define astereognosis
A
inability to identify objects by touch only
12
Q
brodman’s numbers for primary and secondary motor cortex
A
PRI: 4
SEC: 6
13
Q
what is the motor area responsible for?
A
PRI: voluntary mvmts/fine motor mvmts in hand, foot and face
in precentral gyrus
SEC:
PREMOTOR: trunk/girdle muscles
SUPPLEMENTARY: initiation of mvmt
14
Q
lesions of the motor cortex
A
PRI: contralateral paresis/loss of mvmt and dysarthria
SEC: apraxia
15
Q
5 kinds of apraxia
A
ideational: can perform isolated tasks, but cannot combine them
ideomotor: cannot produce mvmt on command
buccofacial: difficulty with purposeful facial mvmts
limb kinetic: inaccurate/clumsy mvmts of distal limb
dressing - cannot put together the sequence of dressing
16
Q
describe broca’s area
A
located in inf frontal gyrus of left lobe
speech production and articulation
lesion:
difficulty expressing using lang
difficulty producing speech
writing affected
expressive aphasia
17
Q
describe wernicke’s area
A
located in left temporoparietal cortex
comprehension of lang
understanding spoken, written, signed lang
lesion:
comprehension impaired
produce meaningless words
alexia
inability to write meaningful words
receptive aphasia
18
Q
brodman’s areas for primary/secondary visual cortex
A
PRI: 17
SEC: 18-21
19
Q
what are the functions of the visual cortex?
A
PRI: light/dark/shapes
located on calcarine sulcus
SEC: analysis of motion, color, recognition of visual objects
located in occipital lobe
20
Q
what are the lesions of the visual cortex?
A
PRI: homonymous hemianopia
SEC: visual agnosia/optic ataxia
21
Q
define homonymous hemianopia
A
loss of 1/2 of visual field
22
Q
brodman’s numbers for auditory cortex
A
PRI: 41
SEC: 22, 42
23
Q
functions of auditory cortex
A
PRI: awareness of intensity of sound (dynamics)
located in lateral fissure on adjacent superior temporal gyrus
SEC: classification of sound
located in posterior 2/3 of superior temporal lobe
24
Q
lesions to auditory cortex
A
PRI: loss of localization of sound
SEC: auditory agnosia
25
what is visual agnosia?
impairment in recognizing visually presented objects despite normal vision
prosopagnosia
simultanagnosia
color agnosia
26
what is auditory agnosia?
inability to differentiate sounds despite intact hearing
phonagnosia - cannot rec familiar voices
amusia - cannot rec different types of music
verbal auditory agnoisa - inability to comprehend spoken word but can read, write and speak normally
27
dorsolateral prefrontal area
brod: 8, 9, 46
goal oriented and self awareness behavior
located in frontal lobe
28
parietotemporal area
brod: 39, 40, 7, 19, 21, 22, 37
sensory integration, problem solving and understanding language
located where pari and temp lobes meet
29
medial dorsal prefrontal area
brod: 8, 9, 10
emotion, motivation, personality
located in frontal lobe
30
describe the primary vestibular cortex
brod: 40, 21, 22
balance, posture, spatial orientation, self motion perception
located at junction of posterior insula, parietal operculum, retro insular region
31
lesion of primary vestibular cortex
change in awareness of head position/mvmt and visual perception
could cause vertigo
32
what is the function of CN 1 - olfactory?
responsible for small
transmits info about odor from olfactory receptors
33
what if there is a lesion in CN 1?
can lead to a loss or impairment of sense of smell
known as anosmia
34
what is the function of CN 2 - optic?
transmits visual info to brain
nerve develops from optic vesicle
35
what is there is a lesion in CN 2?
vision loss - partial or complete
36
what is the function of CN 3 - oculomotor?
moves eye up, down, medially
raises eyelid
constricts pupil to change lens size
37
what id there is a lesion in CN 3?
double vision - diplopia
dilation of pupil
eyelid drooping - ptosis
38
what is the function of CN 4 - trochlear?
moves eyelid medially and down
39
what if there is a lesion in CN 4?
double vision specifically in vertical field
40
what is the function of CN 5 - trigeminal?
facial sensation and muscles of mastication
3 branches
- opthalmic - sensation to forehead, upper eyelid cornea and nose
- maxillary - sensation to cheek, top teeth, roof of mouth, part of nasal cavity
- mandibular - sensation to lower jaw, bottom teeth, tongue, innervates chewing muscles
41
what if there is a lesion in CN 5?
trigeminal neuralgia - sharp burning in face
facial numbness, difficulty chewing, speaking, swallowing
42
what is the function of CN 6 - abducens?
innervated lateral rectus muscle - abduct the eye
43
what if there is a lesion in CN 6?
sixth nerve palsy - double vision in eye misalignment
eye may turn inward when looking straight ahead
44
what is the function of CN 7 - facial?
controls facial muscles/expression, taste salivary and tear glands
sensory: taste and help hearing by innervating parts of ear canal
parasym: salivary and lacrimal glands
5 motor branches
- frontal - forehead
- zygomatic - cheek and eyelid
- buccal - cheek, nose, smile
- marginal mandibular - frown and inner ear
- cervical - platysma, chin/lower mouth
45
what happens if there is a lesion in CN7?
facial nerve palsy - weakness/spasms, dry eyes, dry mouth, sound intolerance, drooping eyelids, lopsided facial appearance, slurred speech
bell's palsy: temp facial paralysis that only affects one side
ramsay hunt syndrome: complication of shingles or chickenpox, can present with paralysis, ear pain, rash
46
what conditions can cause a lesion to CN 7?
guillian barre
tumors in skull
ear infections
stroke
lyme disease
47
what is the function of CN 8 - vestibulocohlear?
vest: activated with head mvmt, helps carry signals along nerve pathway so brain can process info to maintain balance
coch: sound waves vibrate cochlea and activate nerve to carry signals to brainstem to process sound
48
what if there is a lesion in CN 8?
hearing loss, ringing in ears, dizziness/vertigo, nystgmus
49
what is the function of CN 9 - glossopharyngeal?
sensory: sensation from post tongue and pharynx, taste from post tongue, carotid barorecpetors and chemoreceptors
motor: innervates the stylopharyngeus muscle
50
what is there is a lesion in CN 9?
impaired loss of taste from post 1/3 of tongue
reduced sensation from pharynx
weak or absent gag reflex and swallowing difficulties
51
what is the function of CN 10 - vagus?
sensory: sensation from larynx and pharynx
motor: innervates muscles of larynx, pharynx, and soft palate which are essential for swallowing and speech, autonomic functions of the gut
parasym: regulating HR, BP, breathing and digestion
52
what is there is a lesion in CN 10?
laryngeal and pharyngeal paralysis
dysphagia, dysarthria, hoarseness, uvula deviation to unaffected side, parasym dysfunction
53
what is the function of CN 11 - spinal accessory?
innervates SCM and traps enabling head and neck mvmt and shoulder elevation
54
what happens if there is a lesion in CN 11?
weakness or paralysis of neck and shoulder muscles
could cause difficulty turning head, shrugging shoulder, possible shoulder drooping
55
what is the function of CN 12 - hypoglossal?
innervates muscles of tongue
56
what if there is a lesion in CN 12?
weakness, atrophy, possible fasciculations of tongue, deviations of tongue to side with lesion
57
what are the four functional groups of the brainstem?
CN nuclei and related structures
long tracts
cerebellar circuits
reticular formation and related structures: consciousness and autonomic functions
58
how is the brainstem longitudinally divided?
ant: basilar (descending
post: tegmentum (ascending)
midbrain only: tectum
59
what are the descending axons in the basilar section?
corticospinal
corticobrainstme
corticopontine
corticoreticular
60
what are the motor nuclei in the basilar section?
substantia nigra
pontine nuclei
inferior olive
61
what are the components of the tegmentum section?
sensory nuclei and ascending sensory tracts
CN nuclei
MLF - coordinates eye and head mvmt
reticular formation
62
what is the function of the tectum?
reflexive control of intrinsic and extrinsic eye muscles and in mvmts of head
pretectal area
superior and inferior colliculi
63
what are the ascending vertical tracts in midbrain?
DCML
spinalthalamic tract
64
what are the descending vertical tracts in midbrain?
motor:
cortiospinal
corticobrainstem
corticoreticular
corticopontine
autonomic:
sym
parasym
65
describe the DCML
fine touch and proprio
fasciculus gracilis - lower limbs and trunk
fasciculus cuneatus - upper limbs, trunk and neck
66
describe the spinothalamic tract
crude touch, pain, temp
3 order neurons
67
what is the function of the corticospinal tract?
control voluntary mvmt of limbs and trunk
68
what is the function of the corticopontine tract?
involved with motor coordination
69
what is the function of the corticoreticular tract?
regulate posture, muscel tone, reflexes
70
what is the function of inferior colliculi?
relay auditory info from cochlear nuclei
71
what is the function of superior colliculi?
receives sensory/motor info involved in reflexive head and eye mvmts
72
what is the function of the reticular activating system?
activates entire nervous system
73
what is the function of the pons?
facial expression
sensation of taste
move leyes laterally
hearing and balance
planning signals
74
what are the functions of the medulla?
control of head mvmts
coordinates swallowing
regulates cardiovascular, respiratory and visceral activity
75
what are the arteries of the circle of willis?
2 anterior cerebral arteries
2 posterior cerebral arteries
1 anterior communicating artery
2 posterior communicating arteries
2 internal carotid arteries
2 middle cerebral arteries
76
the anterior cerebral arteries brach from which arteries?
internal carotid arteries
anterior circulation
77
the posterior cerebral arteries brach from which arteries?
basilar artery which is formed by the vertebral arteries
posterior circulation
78
what does the posterior cerebral artery supply?
occipital lobe
thalamus
midbrain
inferomedial temporal lobe
79
what does the middle cerebral artery supply?
most of lateral hemisphere
genu of internal capsule
basal ganglia - globus, body of caudate, putamen
80
what does the anterior cerebral artery supply?
parietal lobe
medial frontal lobe
putamen
anterior limb of internal capsule
anterior caudate
81
what happens in an occlusion of the anterior cerebral artery?
personality changes
contralateral hemiplegia and sensory loss
more severe in LOWER limb
82
what happens in an occlusion of the middle cerebral artery?
homonymous hemianopia combines with contralateral hemiplegia and hemisensory
loss involved with UPPER limb and face
language affected if in left hemisphere
nonverbal communication if in right
83
what happens in an occlusion of the posterior cerebral artery?
thalamic syndrome:
eye mvmt paresis/paralysis
affects muscles controlling eye mvmt
cortical blindness
visual agnosia
84
how is CSF formed?
from blood filtration, active transport and facilitated transport
85
where is CSF mostly secreted?
choroid plexuses in ventricles
86
what are the functions of CSF?
protects CNS
regulates extracellular fluid
removes metabolites from brain
87
what is the flow of CSF through ventricels?
choroid plexuses
2 lateral ventricles
interventricular foramen (monro)
3rd ventricle
cerebral aquaduct
4th ventricle
down spinal cord in the central canal
drains into subarachnoid space via luschka (lateral) and magendie (medial)
absorbed nto venous sinuses via arachnoid ville
88
what are the three layers of meninges?
dura mater - surrounds brain inside skull
arachnoid - attached to dura
pia mater - innermost layer attached to brain and SC
89
what are the 3 meningeal spaces?
epidural - between skull and dura
subdural - between dura and arach
subarachnoid - between arach and pia - filled w CSF
90
what is a CSF leak?
CSF escapes from subarachnoid space through hole in dura
results in spontaneous intracranial hypotension
91
what is hydrocephalus?
build up of pressure causing enlargement of ventricles
due to blockage
communicating: ventricular system intact, blocked after 4th ventricle
non-communicating: blockage within ventricular system - most commonly in cerebral aqueduct
92
what is a subarachnoid hemorrhage?
leakage of blood into CSF by trauma or aneurysm rupture
93
primary role of basal ganglia
initiating mvmt
suppressing unwanted mvmt
reg muscle tome and posture
reg emotions
social and goal functions
94
what is the striatum?
caudate
putamen
95
output ganglia
subthalamic nucleus
substantia nigra
96
dopamine
sub nigra to striatum
mod direct and indirect pathway
promotes smooth vol mvmt
97
glutamate
cortex to stri to pal
excites direct and inhibits indirect
98
GABA
inhibits excessive mvmts
99
goal directed loop
eval info for making goals
lateral prefrontal
head of caudate
glob pal
ventral ant thalamus
back to cortex
100
social behavior loop
social cues, self control
ventral prefrontal
head of caudate
sub nigra
mediodorsal thalamus
back to cortex
101
emotions loop
integrate emotions, reward seeking, addiction
medial prefrontal
ventral striatum
glob pal
mediodorsal thalamus
back to cortex
102
direct motor loop
go pathway
activates motor and premotor
initiation
senorimotor cortex
putamen, sub nigra
glob pal
ventrolateral thal
cortex
103
indirect motor loop
nogo
suppresses unwanted mvmt
sensorimotor cortex
putamen
glob pal
subthal
sub nigra
thal
cortex
104
oculomotor loop
spatial attention and eye mvmt
oculomotro cortex
caudate/putamen
glob pal
thal
cortex
105
dystonia
hyperkinetic
mvmt disorder
focal - limited to one part of body
direct and indirect motor loop issues
106
huntington's disease
hyperkinetic
invol jerky mvmts
indirect motor is impaired
107
tourettes
hyperkinetic
tics
3 loops: direct motor, social, emotional
108
dyskinetic cerebral palsy
hyperkinetic
less common than spastic
abnormal tone, poor posture
lesion in basal gang and ventrolateral thal
109
postural instability gait difficulty parkinsons
hypokinetic
tremors at rest
freezing during mvmt
struggle to initiate
speech changes
110
tremor dominant parkinsons
tremors at rest and during vol mvmt
111
functions of cerebellum
coordination
112
vestibulocerebellum
flocculus and nodulus
visual and vestibular input
maintain equilibrium
vestibular nuc to vestibular nuc
113
spinocerebellum
vermis and paravermis
trunk and gross limb mvmts
vestibular nuc to reticular nuc
114
cerebrocerebellum
lateral hemispheres
distal voluntary mvmt
cerebral cortex to red nuc/motor cortex
115
intentional tremors
during purposeful actions
116
decomposition
breaking mvmt into parts
117
paravermal lesions result in
gait ataxia
limb ataxia
118
lateral cerebellar lesion results in
hand ataxia
119
vermal and flocculonodular lesions results in
truncal/gait ataxia
nystagmus
120
what side of body do cerebellar lesions efect
ipsi
121
flow of signal through the eye
optic nerve
chiasm
tract
lateral geniculate
visual cortex
122
describe visual fields for right eye
right cortex to right temporal and left nasal
left cortex to right nasal
123
describe visual fields for left eye
left cortex to left temporal and right nasal
right cortex to left nasal
124
where does the nasal half of the retina cross?
optic chiasm
projects to contralateral side of cortex
125
where does temporal half of retina cross?
chiasm
projects to ipsi side of cortex
126
which labyrinth contains perilymph?
bony
127
which labyrinth contains endolymph?
membranous
128
what does the urticle detect?
horizontal mvmts
129
what does the saccule detect?
vertical mvmts
130
what does the anterior canal detect?
yes motion
sagittal plane
pitch - y axis
131
what does the posterior canal detect?
lateral mvmts
frontal plane
roll - x axis
132
what does the lateral (horizontal) canal detect?
no motion
transverse plane
yaw - z axis
133
what is benign paroxysmal positional vertigo?
dislodged otoconia moving into semicircular canals triggered by head mvmts
134
vestibular neuritis
inflam of vestibular nerve
causes of balance loss and nausea
135
labyrinthitis
infection of vestibular and cochlear parts of ear
causes vertigo and hearing loss
136
vestibular migraine
migraine related to vestib system
causes vertigo
