Neuroanatomy/Physiology Flashcards
1
Q
Nissl substance
A
RER
2
Q
Astrocytes functions lesser known
A
K+ metabolism, glycogen fuel reserve buffer, reactive gliosis in response to neural injury. GFAP is astrocyte marker. Dervied from neuroectoderm.
3
Q
Microglia lesser known facts
A
mesodermal origin. Not readily discernible in Nissl stains. irregular nuclei, small, little cytoplasm. HIV-infected microglia fuse to form multinucleated giant cells in the CNS.
4
Q
What effect does myelin have
A
Increases space constant and inc. conduction velocity
5
Q
Oligodendroglia lesser known facts
A
Neuroectoderm, “fried egg” on H&E stain. Injured in MS, progressive multifocal leukoencephalopathy (PML), and leukodystrophies.
6
Q
Progressive multifocal leukoencephalopathy
A
JC virus in HIV patients. Breaks down white matter, attacking oligodendroglia.
7
Q
Schwann cells lesser known facts (LNFs)
A
Neural crest origin. Destroyed in Guillain-Barre syndrome.
8
Q
Acoustic neuroma
A
Type of schwannoma, internal acoustic meatus (CN VIII): bilateral is neurofibromatosis type 2
9
Q
What layer of peripheral nerve attacked in Guillain-Barre
A
endoneurium
10
Q
What layer is fixed with microsurgery in peripheral nerve?
A
perineurium (permeability barrier)
11
Q
What is the epineurium
A
Deep connective tissue that surrounds entire nerve (fascicles and blood vessels)
12
Q
What is endoneurium
A
It surrounds the axons, but is not the myelin. It holds the axon in the equivalent of CSF.
13
Q
C fibers
A
slow, unmyelinated for pain and temp
14
Q
Adelta fibers
A
fast, myelinated for pain and temp
15
Q
Which sensory corpuscle adapts slowly
A
merkel discs
16
Q
Locus ceruleus NT and location
A
NE and pons
17
Q
Ventral tegmentum and SNc NT and location
A
DA and midbrain
18
Q
Raphe nucleus NT and location
A
5-HT and pons, medulla, midbrain
19
Q
Basal nucleus of Meynert NT
A
ACh
20
Q
Nucleus accumbens NT
A
GABA
21
Q
Openings in Blood-Brain Barrier
A
Area postrema: vomiting after chemo OVLT: osmotic sensing Neurohypophysis release of ADH/oxytocin
22
Q
What is the OVLT?
A
Organum vasculosum of lamina terminalis. Senses osmotic pressure in blood. HYPOTHALAMUS
23
Q
Hypothalamus functions
A
TAN HATS: Thirst and water balance. Adenohypophysis. Neurohypophysis. Hunger. Autonomic regulation. Thermoregulation. Sexual urges.
24
Q
Where is ADH made?
A
Supraoptic nucleus
25
Where is Oxytocin made?
Paraventricular nucleus
26
Lateral hypothalamus
Makes you hungry (grow laterally), damage makes anorexic. Inhibited by leptin.
27
Ventromedial hypothalamus
Makes you satiety. Stimulated by leptin. Damage makes you grow laterally and ventrally. Can be damaged by craniopharyngioma.
28
Anterior hypothalamus
Anterior cooling. parasympathetic
29
Posteriro hypothalamus
Heating, sympathetic. If you destroy posterior, you become poikilotherm (cold-blooded)
30
Suprachiasmatic nucleus function
Sleep
31
Suprachiasmatic nucleus pathway
NE release to pineal gland to melatonin
32
What NTs controlled at night by circadian rhythm
ACTH, prolactin, melatonin, NE
33
What causes the EOMs of REM sleep
PPRF (paramedian pontine reticular formation/conjugate gaze center)
34
What affects REM sleep and delta wave sleep
Alcohol, benzos, and barbs decrease both REM and delta wave sleep
35
NE affects REM how
Dec. REM sleep
36
Treating sleep enuresis
DDAVP, better than imipramine
37
Treating night terrors and sleepwalking
Benzos
38
Highest frequency EEG waves
Beta, when eyes open, alpha is slowly frequency with eyes closed
39
Where are theta waves
N1 (5%)
40
Sleep spindles and K complexes
N2 (45%)
41
Delta waves when
N3 (25%) deepest sleep
42
Where does sleepwalking, night terrors and bedwetting occur
N3
43
REM wave pattern
Beta
44
Sleep wave mnemonic
At night, BATS Drink Blood (beta, alpha, theta, sleep spindles/k complexes, delta, beta)
45
Thalamus receives what senses
Everything except smell
46
Thalamus VPL
Receives spinothalamic and dorsal columns/medial lemniscus: pain/temp, position/pressure/touch/vibration. Relays to primary somatosensory cortex.
47
Thalamus VPM
From trigeminal and Gustatory pathway for face sensation and taste to primary somatosensory cortex.
48
VPM mnemonic
Makeup goes on the face. (VPM)
49
Thalamus LGN
CN II for vision, goes to Calcarine sulcus
50
LGN mnemonic
Lateral = Light
51
Thalamus LGM
From superior olive and inferior colliculus of tectum for hearing. Goes to auditory cortex of temporal lobe.
52
MGN mnemonic
Medial = Music
53
Thalamsu VL
From basal ganglia and cerebellum for motor info, relays to the motor cortex
54
Structures of limbic system
Hippocampus, amygdala, fornix, mammillary bodies, and cingulate gyrus
55
Functions of limbic system
Emotion, long term memory, olfaction, behavior modulation, ANS function
56
Limbic system mnemonic
Famous 5 F's: Feeding, fleeing, fighting, feeling, and sex
57
Cerebellum inputs
Contralateral cortex via middle cerebellar penducle Ipsilateral proprioceptive info via inferior cerebellar peduncle from the spinal cord (input nerves=climbing and mossy fibers)
58
What are the cerebellar peduncles
They are the tracts that connect the cerebellum to the brainstem.
59
Excitatory pathway of Basal Ganglia
This is the direct pathway. Inputs from contralateral cerebral cortex land on putamen (as well as D1 input from SNc) which inhibits the Globus Pallidus Internus which disinhibits the thalamus which increases movement.
60
Inhibitory pathway of Basal Ganglia
Indirect pathway. Putamen inactivates the GPe which disinhibits the STN which activates the GPi inhibition of the thalamus to decrease movement. D2 input stops the putamen efferents which decrease movement.
61
What makes up the striatum
Putamen (motor) + caudate (cognitive)
62
What is the lentiform nucleus
Putamen + globus pallidus
63
What does D2 receptors do
Inhibits the inhibitory pathway
64
What does D1 receptors do
Activates the excitatory pathway
65
What is the SNr
Along with the GPi inhibits the thalamus. Deactivated by the direct pathway and activated by the indirect pathway.
66
What disease has Lewy bodies and found where?
Parkinsons, intranuclear eosinophilic alpha-synuclein inclusions with loss of DA neurons in SNc
67
Signs of Parkinson's
TRAPS: Tremor, cogwheel Rigidity, Akinesia (bradykinesia), Postural instability, Shuffling gait
68
Sxs of huntingtons
Choreiform movements, aggression, depression, dementia
69
Huntington path
Decreased GABA and ACh in brain. Neuron death from NMDA-R binding and glutamate toxicity.
70
Huntington genetics
CAG repeats (anticipation). Aut. dom. on Chromosome 4. Between ages 20-50.
71
Hemiballismus description and location
Contralateral subthalamuc nucleus (e.g. lacunar stroke), 1 arm +/- ipsilateral leg.
72
Athetosis seen where
Fingers, in huntingtons
73
Examples of myoclonus
Jerks; hiccups
74
Myoclonus in what conditions
Renal, liver failure metabolic abnormalities
75
Dystonia examples
Writer's cramp; blepharospasm
76
What worsens essential tremor
Holding posture/limb position
77
Treating essential tremor
Beta blockers, Primidone, EtOH works
78
Primidone MOA
Anticonvulsant that forms a benzo
79
Intention tremor vs. Postural tremor
Intention tremor is Cerebellar dysfunction (swaying zigzag motion). Postural tremor is essential tremor and is a regular frequency.
80
What does Sylvian fissure divide
Temporal and frontal lobes
81
What is the other name for Wernicke's
Associative auditory cortex
82
Central sulcus divides what
Parietal and Frontal lobes
83
Premotor area is part of what
Extrapyramidal circuit
84
What is the homunculus distribution.
Feet is on the inside, progresses up to the thigh which is at the turning point, then goes to hand, then from top of face all the way down to the mouth. Tongue and swallowing are the lowest. Proximal muscles at risk for watershed infarcts.
85
What happens if you lose function of both amygdala
Kluver-Bucy: hyperorality, hypersexuality, disinhibited. Associated with HSV-1
86
What is Gerstmann's syndrome
Damage to L parietal-temporal cortex: agraphia, acalculia, finger agnosia, and left-right disorientation
87
Wernicke-Korsakoff presentation
ACE: ataxia, confusion, eye movement (nystagmus) Memory loss (anterograde/retrograde), confabulation, personality changes.
88
Cerebellar vermis defects result in what
Truncal ataxia, dysarthria
89
Cerebellar hemisphere defects
Intention tremor, limb ataxia, loss of balance, fall towards side of lesion
90
Hippocampus b/l damage
Anterograde amnesia
91
Paramedian pontine reticular formation damage
Eyes look away from side of lesion. This part of the brain initiates saccades towards the ipsilateral side.
92
Frontal eye fields damage
Eyes look toward lesion
93
Sxs of central pontine myelinolysis
Acute paralysis, dysarthria, dysphagia, diplopia, loss of consciousness. Can cause locked-in syndrome.
94
Difference between aphasia and dysarthria
Dysarthria is motor inability, aphasia is higher order deficit in language processing
95
Other name for Broca's area
Inferior frontal gyrus of frontal lobe
96
Broca description
Nonfluent with intact comprehension
97
Wernicke other name
Superior temporal gyrus of temporal lobe.
98
Wernicke presentation
Fluent, impaired comprehension and repetition
99
Can Broca's repeat?
???don't think so
100
Global aphasia
Nonfluent aphasia with impaired comprehension (broca and wernicke's affected)
101
Conduction aphasia cause
Repetition problem only. Damage to left superior temporal lobe and/or left supramarginal gyrus
102
Transcortical motor
Nonfluent but good comprehension and repetition
103
Transcortical sensory
Poor comprehension with fluent speech and reptition
104
Mixed transcortical
Nonfluent speech, poor comprehension, good repetition
105
Know the circle of willis blood flow
.......
106
Anterior choroidal supplies and branches off
Branches off MCA, supplies a lot of things
107
Lenticulostriate branches off and supplies
Branches off MCA, supplies deep cerebral structures
108
What does PCA supply
Posterior, underside, and posterior inside of the cortex
109
What regulates cerebral perfusion
PCO2 regulates it until it maxes out at PCO2 of 90 mmHg. PO2 does not regulate it until the PO2 is \<50 mmHg
110
What does therapeutic ventilation do
Blows off CO2 so blood flow decreases (vasoconstrict), works on the same curve as when PCO2 is rising.
111
Lateral Medullary syndrome
Wallenberg. PICA infarction. Nucleus ambiguus effects are specific to PICA lesions. Hoarseness and dysphagia.
112
Medial Medullary syndrome
Infarct of paramedian branches of ASA and vertebral arteries. Commonly bilateral stroke.
113
Lateral pontine syndrome
AICA stroke. Facial nucleus effects are specific to AICA lesions.
114
What stroke leads to Locked-In syndrome
Basilar artery stroke
115
Tongue deviates to one side
ASA stroke leading to ipsilateral hypoglossal dysfunction
116
PICA stroke
Ipsilateral face temp and pain; contralateral body pain and temp. DYSPHAGIA, HOARSENESS (NUCLEUS AMBIGUUS)
117
AICA stroke
Similar to PICA with Vertigo, Vomiting, nystagmus, but facial PARALYSIS.
118
Most common site of saccular aneurysm
ACom meeting with ACA causes visual field defects
119
PCom aneurysm
CN III palsy: eye down and out, ptosis and pupil dilation
120
Most common compilcation of Berry aneurysms
Rupture leading to SAH. Another complication is bitemporal hemianopia via compression of optic chiasm.
121
Berry aneurysm assoicated with
ADPKD, Ehlers-Danlos syndrome, and Marfans. Age, HTN, smoking, Blacks
122
Charcot-Bouchard microaneurysm
Chronic HTN; affects small vessels (e.g. basal ganglia, thalamus)
123
Central post-stroke pain syndrome
Neuropathic pain due to thalamic lesions. Paresthesias turn to dyesthesias and allodynia. Occurs in 10% of stroke patients.
124
Epidural hematoma cause
Middle meningeal artery (from maxillary artery) secondary to temporal bone fracture.
125
Epidural hematoma defects
Transtentorial herniation, CN III palsy
126
Epidural appearance on imaging
Biconvex, does not cross suture lines, cross falx, tentorium
127
Tentorium cerebelli
Between cerebrum and cerebellum
128
Falx cerebri
Between the L and R hemispheres of cerebrum
129
What are the suture lines?
The skull bone suture lines
130
Why can't epidural cross suture lines?
Because at suture lines, the dura is tightly bound to the calvarium.
131
Why can't subdural cross falx/tentorium
Because it is constrained within the dura which the falx is a part of. Epidurals aren't within the dura so they can cross the falx.
132
natural history of SAH and how to treat
Xanthochromic tap, 2-3 days afterwards vasopasm due to blood breakdown, treat with nimodipine, cannot be seen on CT.
133
Causes of intraparenchymal (HTN) hemorrhage
MCC is systemic HTN: also seen with amyloid angiopathy, vasculitis, and neoplasm. Seen in basal ganglia and internal capsule, but can be lobar
134
Most vulnerable parts of brain to ischemia
Hippocampus (hypoxia=hypocampus), neocortex, cerebellu, watershed areas. 5 minutes to irreversible damage.
135
Imaging for ischemia
diffusion weight MRI detects it in 3-30 minutes. Dark abnormality on noncontrast CT in 12-24 hrs.
136
Stroke histo 12-48 hrs
Red neurons
137
Stroke histo 24-72 hrs
Necrosis + PMNs
138
Stroke histo 3-5 days
Macrophages
139
Stroke histo 1-2 weeks
Reactive gliosis + vascular proliferation
140
Stroke histo \>2 weeks
Glial scar
141
Most common site of intracerebral hemorrhage
basal ganglia
142
Common site of thrombotic stroke
MCA. Ischemic strokes result in liquefactive necrosis.
143
tPA indications
Within 3-4.5 hr of onset and no hemorrhage/risk of hemorrhage
144
Treating ischemic stroke
tPA. Aspirin. Clopidogrel; BP control, blood sugars and lipids, a. fib
145
Name the venous sinuses
superior Sagittal sinus, transverse sinuses, straight sinus from the ventromedial aspects (Great cerebral vein of Galen and Inferior sagittal sinus from above the ventricles). Occipital sinus from inferior sinus. All of these meet up at the back, then drain through the transverse sinuses to the sigmoid sinus into the internal jugular.
146
Cavernous sinus connections
Connects to sphenoparietal sinus which connects to superior sagittal sinus and transverse sinus
147
Superior ophthalmic brain movement
Connects to cavernous sinus
148
Lateral ventricle circulation
Choroid plexus in the lateral ventricles produces CSF which flows through the foramen of Monro into the third ventricle between the thalami which connects to the fourth ventricle between the cerebellum and brainstem by the cerebral aqueduct of Sylvius. From there CSF leaks out through the foramens of Luschka (lateral) and the foramen of Magendie into the subarachnoid space of the spinal cord which then circulates around to the top of the brain and is reabsorbed by the arachnoid granulations.
149
CSF made by what cells
Ependymal cells of choroid pleuxs
150
Normal pressure hydrocephalus presentation
Urinary incontinence, dementia, ataxia. "Wet, wobbly, and wacky
151
NPH path
No increased subarachnoid space volume, expansion of ventricles distorts corona radiata.
152
Hydrocephalus ex vacuo
Cortical atrophy leads to increased CSF but no increased pressure (Alzheimers, advanced HIV, Pick disease)
153
How many spinal nerves
31: 8C, 12T, 5L, 5S, 1Coccygeal (31 flavors of Baskin-Robbins ice cream)
154
Lumbar disc herniations at what levels most common
L4-L5 and L5-S1
155
Where does spinal cord end
L1-L2 vertebrae, subarachnoid space extends to S2 vetebrae.
156
Lumbar puncture performed where
L3-L4 or L4-L5 (level of cauda equina)
157
Organization of arms/legs in the spinal tracts
CST and STT are lower extremities laterally. Dorsal columns are lower extremities medially.
158
Know the pathways and synapses of the tracts
Dorsal column: Dorsal root ganglion has the first cell body, synapses at nucleus gracilis/cuneatus in medulla, Decussates and moves up medial lemniscus to the VPL then to sensory cortex Spinothalamic tract: Dorsal root ganglion to synapse in ipsilateral gray matter, decussates at anterior white commissure and ascends contralaterally to the VPL. Corticospinal tract: UMN fibers decussate at caudal medulla (pyramidal decussation) and descend contralaterally to synapse on LMN in anterior horns.
159
MS spinal cord lesions
White matter, random and assymetric; scanning speech, intention tremor, nystagmus
160
Scanning speech
Pausing between words and weird enunciation
161
Anterior horns spinal cord lesion
Poliomyelitis and spinal muscular atrophy (Werdnig-Hoffmann disease) Flaccid paralysis.
162
Amyotrophic lateral sclerosis spinal lesion
Lateral CST and Anterior Horn damage, no sensory, cognitive, or oculomotor deficits
163
Causes of ALS
Defect in superoxide dismutase 1.
164
ALS presentation
Fasciculations with eventual atrophy and weakness of hands; fatal
165
ALS tx
Riluzole inc. surivval by dec. presynaptic glutamate release
166
ALS mnemonic
For Lou Gehrgis, give riLOUzole
167
ASA occlusion spinal lesion
Spares dorsal columns and Lissauer tract
168
Lissauer tract
???????
169
Watershed in spinal cord
Upper thoracic ASA territory, artery of Adamkiewicz supplies ASA below T8
170
Tabes dorsalis path
Tertiary syphilis demyelinates dorsal columns and roots.
171
Tabes dorsalis associated with what
Charcot joints, shooting pain, Argyll Robertson pupils
172
Tabes dorsalis exam findings
Absent DTRs and positive Romberg
173
Syringomyelia path and presentation
Syrinx damages anterior white commissure of spinothalamic tract (2nd-order neurons). b/l loss of pain and temp (C8-T1); Chiari I; can expand and affect other tracts
174
Subacute combined degeneration presentation
Demyelination of dorsal columns, lateral CST, and spinocerebellar tracts; ataxic gait, paresthesia, impaired position, and vibration sense
175
Subacute combined degeneration causes
B12 or vitamin E deficiency
176
Spinocerebellar tracts
Spinal cord to cerebellum, golgi tendon organs and muscle spindles, first order neurons
177
Poliomyelitis path
Fecal-oral, replicates in oropharynx and small intestine before spreading via bloodstream to the CNS. Infection causes destruction of cells in ant. horn of spinal cord (LMN death).
178
Poliomyelitis presentation
LMN signs, general constitutional signs of infection
179
Poliomyelitis findings
CSF with inc. WBCs and slight inc. of protein (no CSF glucose change). Virus recovered from stool or throat.
180
Werdnig-Hoffman disease
Spinal Muscular Atrophy. Congenital degeneration of ant. horns of spinal cord leading to LMN lesion. Floppy baby with hypotonia and tongue fasciculations. Infant type median age of death of 7 moonths. Aut. rec.
181
