Exam 1 - Week 1 Flashcards
1
Q
which cranial nerves have parasympathetic fibers
A
III, VII, IX, X
2
Q
which cranial nerves are sensory only
A
I, II, VIII
3
Q
muscles innervated by CN III
A
superior palpebral levator, all extraocular muscles except lateral rectus and superior oblique
4
Q
muscles innervated by CN IV
A
superior oblique
5
Q
muscles innervated by CN VI
A
lateral rectus
6
Q
clinical signs of CN III lesion
A
Ptosis, opthalmoplegia with eye turned down and out, mydriasis and loss of accommodation
7
Q
clinical signs of CN IV lesion
A
diplopia, extorsion or eye, weakness in depression of adducted eye
8
Q
clinical signs of cranial nerve VI lesion
A
diplopia, medial deviation, abductor paralysis
9
Q
describe pupillary light reflex
A
CNII is afferent sensory and CN III is efferent parasympathetic via Edinger-Westphal nucleus in midbrain
10
Q
trigeminal nerve function
A
sensation from face and structures of eyeball, motor innervation of muscles of mastication
11
Q
clinical signs of trigeminal nerve lesion
A
atrophy of muscles of mastication with ipsilesional deviation and facial hemianesthesia on ipsilateral side
12
Q
trigeminal neuralgia ssx
A
excruciating, paroxysmal pain, usually worse on right, precipitated by tapping nerve, eating, or movement.
13
Q
trigeminal neuralgia tx
A
carbamazepine, anticonvulsants (gabapentin/lamotrigine/phenytoin), surgical decompression
14
Q
functions of cranial nerve VII
A
motor to muscles of facial expression, parasympathetic to lacrimal/submandibular/sublingual glands, sensory to taste in anterior 2/3 of tongue
15
Q
clinical signs of facial nerve lesion
A
ipsilateral hemiparalysis of face, eye dryness, anterior agusia, hyperacusis, dry mouth, loss of corneal reflex
16
Q
major cause of facial nerve dysfunction
A
Bell’s palsy
17
Q
Bell’s palsy causes
A
herpes, tumors of internal meatus, trauma
18
Q
Bell’s palsy tx and prognosis
A
antivirals, oral steroids; recovery in around 6 months
19
Q
functions of CN IX
A
motor to stylopharyngeus, parasympathetic to parotid gland, taste to posterior 1/3 of tongue, sensory to posterior oral cavity, tonsils, auditory tube, middle ear; chemo/baroreceptor: carotid sinus
20
Q
clinical signs of CN IX lesion
A
right posterior ageusia, dysphagia
21
Q
Vagus nerve functions
A
motor to palatal, pharyngeal, vocal muscles. Parasympathetic to cardiac/pulmonary/enteric plexuses. Taste to epiglottal and palatal regions. Sensory to epiglottis, larynx, GI tract, external ear and auditory canal. Chemo/baroreceptor: Aortic bulb and sinus
22
Q
clinical ssx of vagus nerve lesion
A
ipsilateral hemisanesthesia of pharynx, larynx and auditory canal. Ipsilateral palatal arch sagging and deviation of uvula, right vocal muscles paralysis
23
Q
mydriasis aka
A
blown pupil
24
Q
signs of accessory muscle lesion
A
weakness of contralateral head turning
25
hypoglossal nerve lesion signs
tongue atrophy, ipsilesional deviation
26
what structures travel through cavernous sinus
carotid artery, CN III, CN IV, CN VI, CNV1, CNV2
27
3 main types of neural tube defects
spina bifida oculta, meningocele, myelomeningocele
28
the neural tube defects affect which part of neural tube
posterior
29
spina bifida occulta ssx
asymptomatic with hair/dimple/lipoma, but can cause problems later
30
AFP for spina bifida oculta
normal
31
what is chiari II malformation
cerebellar tonsil and vermis herniation
32
chiari II malformation ssx
hydrocephalus, CN IX/X dysfunction
33
when do neural tube defects manifest
4th week
34
meningocele/myelomeningocele AFP
elevated
35
meningocele/myelomeningocele ssx
limb, bowel, and bladder dysfunction
36
risk factors for neural tube defects
previous birth with NTD, ethnicity (Ireland/Scotland), folate deficiency, anti-seizure medication, obesity, poorly-controlled DM
37
prevention of neural tube defects
folic acid or B9 complex vitamin supplementation 4 mg daily at least through 1st trimester
38
elements of telencephalon
cortex, corpus striatum, lateral ventricles, CN I
39
elements of diencephalon
thalamus, hypothalamus, subthalamus, epithalamus, 3rd ventricle, CN II
40
elements of mesencephalon
colliculi, cerebral peduncle, cerebral aqueduct, CN III/IV
41
elements of metencephalon
pons, cerebellum, 4th ventricle, CN V, CN VI, CN VII, CN VIII
42
elements of myelencephalon
medulla, pyramids, olive, 4th ventricle, cranial nerves IX-XII
43
what properties allow for better BBB penetration
lipid solubility, low molecular weight, nonpolar
44
what polar molecules are able to cross BBB without energy
glucose and amino acids
45
what polar molecules can penetrate BBB with energy
insulin, transferrin
46
what constitutes the BBB
tight junctions between capillary endothelial cells and surrounding layers of astrocyte end-feet
47
what parts of brain lack BBB and what do they have instead
circumventricular organs; fenestrated capillaries
48
what can cause increased permeability of BBB
stroke, tumors, trauma, infections, seizures, MS, neurodegenerative disease
49
how much CSF is produced per hour
25 ml
50
how much CSF is present at any one time
125-150 ml
51
what is hydrocephalus
dilation of the ventricular system
52
cause of noncommunicating hydrocephalus
obstruction
53
what is the anterior circulation to the brain
internal carotid arteries
54
what is the posterior circulation to the brain
vertebral arteries
55
branches of internal carotid
middle cerebral, anterior cerebral
56
what area of the brain is supplied by middle cerebral artery
lateral convexity of cerebral cortex including lateral portion of primary motor and somatosensory cortex, lateral temporal lobe, and variable portion of parietal lobe
57
branches of vertebral arteries
basilar, posterior cerebral artery
58
what area of the brain is supplied by anterior cerebral artery
medial surface of frontal lobe to anterior parietal lobe, including medial somatosensory cortex representing lower leg
59
what area of the brain is supplied by posterior cerebral artery
occipital lobe and inferior surface of temporal lobe
60
what supplies blood to brainstem and cerebellum
basilar, PICA, AICA, SCA
61
dendrites function
relay impulses toward cell body
62
anterograde axonal transport carries
nutrients, enzymes, herpes reactivation
63
retrograde axonal transport carries
materials for lysis/recycling, tetanus toxin, viruses trying to get into CNS
64
astrocytes function
support/anchor neurons, determine capillary permeability
65
microglia function
phagocytosis
66
ependymal cells function
form permeable barrier
67
oligodendrocytes AKA and function
macroglia, create myelin sheath in CNS
68
satellite cells function
astrocytes of PNS
69
schwann cells function
Create myelin sheath in PNS
70
catecholamine neurotransmitters
norepinephrine, dopamine
71
where is norepi produced
locus ceruleus, autonomic neurons
72
where is dopamine produced
substantia nigra, ventral tegmental area
73
indoleamine neurotransmitters
serotonin
74
serotonin AKA
5-HT
75
where is serotonin produced
raphe nucleus
76
where is adenosine produced
widely distributed in CNS
77
opioid neurotransmitters
enkephalins, endorphins
78
where are opioid neurotransmitters produced
widely distributed opioidergic neurons
79
endocannibinoid neurotransmitter
anandamide
80
quaternary amines neurotransmitter
acetylcholine
81
where is acetylcholine produced
basal forebrain, autonomic/motor neurons
82
purine neurotransmitter
adenosine
83
where is broca's area
frontal lobe, inferior frontal gyrus
84
flow of CSF
produced by choroid plexus, then flows from lateral ventricles through the foramen of monroe to the third ventricle, then to the fourth ventricle, then through the foramen of magendie (medial) and foramen of luschka (lateral) to the subarachnoid space where it gets reabsorbed by arachnoid granulations and drains into the superior sagital sinus and reenters general circulation via the jugular vein
85
pathophys of communicating hydrocephalus
decreased CSF absorption leading to increased ICP
86
what is IIH/pseudotumor cerebri
increased ICP in the absence of obvious cause
87
pseudotumor cerebri ssx
intractable, disabling headaches, papilledema/vision loss, pulsatile tinnitus
88
pseudotumor cerebri tx
acetazolamide
89
what is hydrocephalus ex vacuo
appearance of hydrocephalus due to cortical atrophy with sulci enlargement
90
what is normal pressure hydrocephalus
idiopathic enlargement of all ventricles causing compression of corona radiata
91
normal pressure hydrocephalus classic triad of ssx
urinary incontinence (wet), gait disturbance (wobbly), dementia (wacky)
92
normal pressure hydrocephalus tx
VP shunt
93
primary route for CSF drainage back to venous system
superior sagital sinus
94
longitudinal fissure
separates two hemispheres
95
central sulcus
separates frontal and parietal lobes
96
sylvian/lateral fissure
separates temporal from frontal/parietal lobes
97
parieto-occipital sulcus
separates parietal lobe from occipital lobe
98
frontal lobe functions
primary motor cortex, speech, frontal eye fields, higher executive function, decision-making, response inhibition
99
Parietal lobe functions
multimodal sensory integration, primary somatosensory cortex
100
temporal lobe functions
hearing (primary auditory cortex), language (Wernicke's area), olfactory cortex, memories, emotions
101
occipital lobe functions
visual processing (primary visual cortex)
102
ssx of MCA stroke
contralateral paralysis and sensory loss of face and upper limb. If left MCA, Broca and Wernicke aphasias
103
ssx of ACA stroke
contralateral paralysis and sensory loss of lower limb
104
ssx of PCA stroke
contralateral visual field deficit (hemianopia)
105
ACA and MCA derive blood supply from ______
internal carotid arteries
106
PCA derives blood supply from
posterior circulation
107
venous drainage from brain is provided by _____
internal jugular
108
blood supply to spinal cord
anterior spinal artery and paired posterior spinal arteries
109
which cranial nerves are above the pons
I-IV
110
which cranial nerves are in the midbrain
III, IV
111
which cranial nerves are in the pons
V-VIII
112
which cranial nerves are in the medulla
IX-XII
113
origin of CN III parasympathetic fibers
Edinger-Westphal nucleus
114
CN IV lesion ssx
diplopia, extorsion with compensatory head tilt, weakness in depression of adducted eye, difficulty with walking down steps and reading
115
causes of CN III lesions
compression, posterior communicating artery aneurysm, microvascular ischemia
116
what is the most common isolated nerve palsy due to trauma
trochlear nerve
117
causes of abducens nerve palsies
microvascular ischemia, compression, trauma, increased ICP
118
abducens nerve palsy ssx
impaired abduction, horizontal diplopia that is worse when looking toward affected side, head turned toward affected side at rest, inward deviation of affected eye at rest
119
branches of trigeminal nerve
ophthalmic, maxillary, mandibular
120
afferent limb of corneal reflex
V1
121
efferent limb of corneal reflex
VII: facial nerve to orbicularis oculi
122
afferent gag reflex
CN IX
123
efferent gag reflex
CN X
124
lacrimation reflex afferent
V1
125
lacrimation reflex efferent
VII
126
jaw jerk reflex afferent
V3
127
jaw jerk reflex efferent
V3
128
typical presentation of cavernous sinus syndrome
variable opthalmoplegia, Horners syndrome
129
common causes of cavernous sinus syndrome
carotid-cavernous fistula, thrombosis, pituitary tumor
130
presentation of aneurysm in posterior communicating artery
pure CN III palsy with pupil involvement: Ptosis, enlarged/unresponsive pupil, eye down and out, diplopia
131
where is primary motor cortex
in precentral gyrus
132
premotor area function
assembles complex motor programs
133
superior parietal lobule function
contains somatosensory association cortex to integrate sensory information
134
where is the primary auditory cortex
transverse temporal gyri in temporal lobe
135
where is wernicke's area
superior temporal gyrus
136
where is the primary visual cortex
in the occipital pole
137
where is cingulate gyrus
within superior limbic lobe
138
major branch of vertebral artery
anterior inferior cerebllar artery
139
posterior communicating artery
connects each internal carotid and PCA to create anastomosis between anterior and posterior systems
140
anterior communicating artery
connects the bilateral ACA
141
location of ependymal cells
ventricles and central canal of spinal cord, part of hypothalamus, choroid plexus, retina
142
what is reactive gliosis
astrocytes responding to injury
143
major difference between oligodendrocytes and schwann cells re: relationship with axon
1 oligodendrocyte can interact with 50 axons, whereas 1 schwann cell can only interact with one axon
144
which cranial nerve is myelinated by oligodendrocyte
II
145
main reservoir of HIV in brain
microglia
146
describe neuronal action potentials
1. resting state: all gated ion channels closed.
2. synaptic potential causes sodium influx, leading to rapid depolarization
3. K+ channels open, causing potassium efflux and repolarization of membrane potential
147
propagation velocity is highest in ____
myelinated and large fibers
148
types of peripheral nerve damage
neuropraxia, axonotmesis, neurotmesis
149
what is neurapraxia
mild injury that causes focal demyelination without affecting integrity of the nerve, with full recovery in days-weeks
150
What is axonotmesis
local but irreversible axonal/myelin sheath damage that can be caused by crush injuries, nerve stretch injuries, or percussion injuries. Endoneurium and perineurium remain intact
151
what happens proximal to axonotmesis injury
cell body swells and cytoplasmic chromatolysis occurs
152
what happens distal to axonotmesis injury
Wallerian degeneration
153
axonotmesis prognosis
partial recovery in months to years
154
what is neurotmesis
severe sharp/traction injuries involving irreversible damage to axon, myelin sheath, and stroma
155
neurotmesis prognosis
regeneration will not occur without surgical anastomosis; with surgery recovery of function is possible in months-years. Without surgery, nerve will attempt to regenerate and form a neuroma
156
what happens during first 12-24 hours after CNS neuron insult
intense cytoplasmic eosinophilia and nuclear pyknosis
157
what happens 24 hours-5 days after CNS neuron insult
liquefactive necrosis and Wallerian degeneration
158
what happens days to weeks after a CNS neuron insult
cyst formation with reactive gliosis and vascular proliferation
159
what happens long-term after CNS neuron insutl
glial scar formation
160
Ach is broken down by
acetylcholinesterase
161
acetylcholine binding sites
nicotinic (ligand-gated) and muscarinic (G protein coupled)
162
where are nicotinic Ach receptors found
neuromuscular junction, autonomic ganglia, CNS
163
where are muscarininc Ach receptors found
myocardium, smooth muscle, CNS
164
what is the most common neuromuscular junction disorder
myasthenia gravis
165
age of onset for myasthenia gravis
20-30 y/o for females, 60-80 y/o for males
166
myasthenia gravis pathophys
antibodies against post-synaptic Ach receptors
167
myasthenia gravis ssx
gradual onset fatigable weakness with oculobulbar muscles often affected first, and proximal muscles affected more
168
myasthenia gravis is associated with ___
thymoma and autoimmune thyroiditis
169
myasthenia gravis treatments
cholinesterase inhibitors like pyridostigmine, immunosuppressants
170
lambert eaton age of onset
4th decade for females, 6th decade for males
171
lambert eaton is associated with
small cell lung cancer
172
lambert eaton pathophys
antibodies against presynaptic voltage gated calcium channels - prevents ACh release
173
Lambert Eaton ssx
gradual onset weakness that improves with exercise beginning in proximal legs, then proximal arms, then distal extremities with oculobulbar regions affected last. Also ssx caused by decreased parasympathetic activity, hyporeflexia
174
reflexes in MG vs lambert eaton
normal in MG, diminished in LE
175
what breaks down dopamine
MAO and COMT
176
what breaks down norepi
MAO and COMT
177
what breaks down serotonin
MAO and aldehyde dehydrogenase
178
what breaks down GABA
GABA transaminase
179
histamine functions
controls arousal, attention, sleep, satiety, equilibrium
180
what is anencephaly
failure of neuropore closure resulting in lack of forebrain and an open calvarium causing a frog-liked appearance
181
what is spina bifida occulta
failure of caudal neuropore closure without herniation. Dura mater is intact
182
what is meningocele
meninges but not bony tissue herniate through bony defect
183
what is meningomyelocele
meninges and neural tissue herniate through bony defect
