First Aid Flashcards
CNS/PNS origins
Neuroectoderm: CNS neurons, ependymal cells, oligodendroglia, astrocytes
Neural crest: PNS neurons, Schwann cells
Mesoderm: microglia
3 findings in Neural tube defects
Ass w/ low folic acid intake before + during pregnancy
High AFP in amniotic fluid + maternal serum (except spina bifida occulta)
High AChE in amniotic fluid
4 findings of Anencephaly
High AFP
Polyhydramnios
Ass w/ maternal type I db
Folate supplementation lowers risk
5 findings in Holoprosencephaly
Failure in separation of L + R hemispheres \+/- mutations in sonic hedghog Moderate: cleft lip/palate Severe: cyclopia In Patau sd + fetal alcohol sd
3 findings in Chiari II malformation
Herniation of cerebellar vermis (foramen magnum)
Aqueductal stenosis / hydrocephalus
Ass w/ lumbosacral meningomyelocele
3 findings in Dandy-Walker syndrome
Agenesis of cerebellar vermis
Cystic enlargement of 4th ventricle
Ass w/ noncommunicating hydrocephalus / spina bifida
4 characteristics of Chiari I malformation
Cerebellar tonsillar ectopia
Congenital
Asymptomatic in childhood
Headaches + cerebellar symptoms
3 findings in Syringomyelia
Cystic cavity in central canal of spinal cord
Spinothalamic tract damaged (pain+temperature bilat. loss)
Ass w/ Chiari malfo, trauma, tumors
CN for sensation + taste of tongue
Anterior 2/3: sensation V3 + taste VII
Posterior 1/3: sensation IX + taste IX
Extreme posterior: sensation X + taste X
Motor innervation of tongue
CN XII: hyoglossus, genioglossus, styloglossus
CN X: palatoglossus
Wallerian degeneration
Injury to axon
Degeneration distal to injury
Axonal retraction proximal to injury
Potential regeneration (if PNS)
3 characteristics of astrocytes
From neuroectoderm
Marker: GFAP
Reactive gliosis (glial scar) secondary to neural injury
4 characteristics of microglia
From mesoderm
Phagocytic scavenger cells of CNS
Activated when tissue damage
HIV-infected: giant cells in CNS
4 characteristics of myelin
CNS: oligodendrocytes - PNS: Schwann cells
Reduces time constant
Raises space constant
Raises conduction velocity
2 diseases that affect Schwann cells
Guillain-Barré syndrome Vestibular schwannoma (CN VIII)
4 findings of oligodendroglia
From neuroectoderm
Predominant glial cell in white matter
Each myelinates ~30 axons in CNS
Injured in MS, PML, Leukodystrophies
3 layers of peripheral nerve
Endoneurium (inflammatory infiltrate in Guillain-Barré)
Perineurium (rejoined in microsurgery)
Epineurium (surrounds fascicles + blood Vx)
Neurotransmitter changes in Anxiety
Low GABA
Low Serotonin
High NE
Neurotransmitter changes in Depression
Low Dopamine
Low NE
Low Serotonin
Neurotransmitter changes in Schizophrenia
High Dopamine
Neurotransmitter changes in Alzheimer disease
Low Acetylcholine
Neurotransmitter changes in Huntington disease
Low ACh
Low GABA
High Dopamine
Neurotransmitter changes in Parkinson disease
Low Dopamine
High Ach
High Serotonin
3 structures of blood-brain barrier
Tight junctions (nonfenestrated capillary endothelial cells)
Basement membrane
Astrocyte foot processes
3 brain regions with fenestrated capillaries
Area postrema (vomiting post-CT)
OVLT (osmotic sensing)
Neurohypophysis (ADH release)
7 functions of Serotoninergic neurons
Sleep-wake cycle Anxiety Mood Psychosis Sexuality Eating behavior Impulsivity
7 functions of Hypothalamus
Thirst + water balance Adenohypophysis control Makes ADH + oxytocin released to Neurohypophysis Hunger Autonomic regulation Temperature regulation Sexual urges
Lateral + Ventromedial areas of hypothalamus
Lateral: Hunger - stimulated by ghrelin - inhibited by leptin
Ventromedial: Satiety - stimulated by leptin
Anterior + Posterior areas of hypothalamus
Anterior: cooling, parasympathetic
Posterior: heating, sympathetic
Suprachiasmatic + supraoptic + paraventricular nuclei of hypothalamus
Suprachiasmatic: circadian rhythm
Supraoptic: ADH
Paraventricular: Oxytocin
2 characteristics of circadian rhythm
Regulated by environment
Controls nocturnal release of ACTH, prolactin, melatonin, NE
4 characteristics of REM sleep
Extraocular mvts due to PPRF
High ACh
Every 90min and longer through the night
Shorter when alcohol, NE, benzodiazephines, barbiturates
Inputs of ventral postero-lateral + ventral postero-medial nuclei of Thalamus
Ventral postero-lateral: spinothalamic + dorsal columns/medial lemniscus
Ventral postero-medial: trigeminal + gustatory pathway
Inputs of lateral geniculate + medial geniculate nuclei of thalamus
Lateral geniculate: CN II
Medial geniculate: superior olive + inferior colliculus of tectum
Inputs of ventral lateral nucleus of thalamus
Ventral lateral: basal ganglia, cerebellum
5 structures + 5 functions of Limbic system
Hippocampus Amygdala Fornix Mammillary bodies Cingulate gyrus
Emotion Long-term memory Olfaction Behavior modulation ANS function
4 dopaminergic pathways + functions + 2 factors altering them
Mesocortical: regulates cognition + behavior
Mesolimbic: regulates cognition + behavior
Nigrostriatal: regulates coordination of voluntary mvts
Tuberoinfundibular: inhibits prolactin secretion
Drugs (antipsychotics) Movement disorders (Parkinson)
Effects of the 4 dopaminergic pathways
Mesocortical: low activity will give negative symptoms
Mesolimbic: high activity will give positive symptoms
Nigrostriatal: low activity will give extrapyramidal symptoms
Tuberoinfundibular: low activity will raise prolactin
2 functions + 2 inputs + 1 output of Cerebellum
Modulates movement
Aids in coordination + balance
From contralateral cortex (middle cerebellar peduncle)
From ipsilateral proprioception (inferior cerebellar peduncle)
To contralateral cortex (superior cerebellar peduncle)
Lateral + Medial lesions of cerebellum
Lateral: voluntary mvt of extremities; fall toward injured side
Medial: midline structures + flocculonodular lobe; truncal ataxia (wide-based) + nystagmus + head tilting; bilateral motor deficits of axial + proximal limbs
2 functions + input + output of Basal ganglia
For voluntary mvts + postural adjustments
From cortex
Negative feedback to cortex
Excitatory + inhibitory pathways of basal ganglia
Excitatory: cortex +) striatum +) GABA -) GPi +) thalamus +) motion
Inhibitory: cortex +) striatum +) GABA -) GPe +) STN +) GPi -) thalamus -) motion
Athetosis, dystonia, myoclonus
Athetosis: basal gg, slow writhing mvt, fingers
Dystonia: sustained, involuntary muscle contraction
Myoclonus: sudden, brief, uncontrolled muscle contraction
Chorea, hemiballismus
Chorea: basal gg, sudden jerky purposeless mvt
Hemiballismus: contralateral subthalamic nucleus, sudden wild flailing arm + ipsilateral leg
Essential tremor, intention tremor, resting tremor
Essential: high-fqcy w/ sustained posture, worse w/ mvt-anxiety, ttt non selective beta-blocker/primidone.
Intention: cerebellar dysfunction, slow zigzag when pointing
Resting: Parkinson, uncontrolled mvt at rest, distal limbs, better w/ intentional mvt
4 causes + 2 ttt of Restless leg syndrome
Idiopathic
Iron deficiency
Uremia
Diabetes
Avoid aggravating factors (alcohol, sleep depriv.)
Dopa-agonists (Pramipexole)
3 findings + 5 symptoms of Parkinson disease
Degeneration of CNS
Lewy bodies
Loss of dopaminergic neurons of substantia nigra pars compacta
Tremor Rigidity Akinesia/bradykinesia Postural instability Shuffling gait
Advanced treatment of Essential tremor + Parkinson disease
Essential tremor: high fqcy stimulation of ventral intermediate nucleus of thalamus
Parkinson: high fqcy stimulation of globus pallidus internus or subthalamic nucleus
Excitatory + inhibitory pathways of basal ganglia
Excitatory: cortex +) striatum +) GABA -) GPi +) thalamus +) motion
Inhibitory: cortex +) striatum +) GABA -) GPe +) STN +) GPi -) thalamus -) motion
4 symptoms + 5 findings in Huntington disease
Choreiform movements
Aggression
Depression
Dementia
Low Ach, Low GABA, High dopamine Neuronal death (NMDA-R binding + glutamate excitotoxicity) Atrophy of caudate + putamen w/ hydrocephalus ex vacuo
2 findings in bilateral Amygdala lesion
Klüver-Bucy syndrome (disinhibited behavior)
Ass w/ HSV-1 encephalitis
3 findings in Frontal lobe lesion
Right side: disinhibition
Left side: impaired performance (concentration, orientation, judgment), depressed affect, apathy
+/- primitive reflexes
2 findings in Nondominant parietal cortex lesion
Hemispatial neglect syndrome
Constructional apraxia
1 finding in Dominant parietal cortex lesion
Gerstmann syndrome (Agraphia, Acalculia, Finger agnosia, Left-right disorientation)
1 finding in Reticular activating system (midbrain) lesion
Reduced levels of arousal + wakefulness
1 finding in bilateral Mamillary bodies lesion
Wernicke-Korsakoff syndrome (confusion, ophthalmoplegia, ataxia, memory loss, confabulations, personality changes)
3 findings + 2 diseases of Basal ganglia lesion
Resting tremor
Chorea
Athetosis
Parkinson disease
Huntington disease
4 findings in Cerebellar hemisphere
Intention tremor
Limb ataxia
Loss of balance
Ipsilateral deficits (falls toward side of lesion)
2 findings in Cerebellar vermis lesion
Truncal ataxia
Dysarthria
1 finding in Subthalamic nucleus lesion
Contralateral hemiballismus
1 finding in bilateral Hippocampus lesion
Anterograde amnesia
1 finding in Paramedian pontine reticular formation lesion
Eyes look away from side of lesion
1 finding in Frontal eye fields lesion
Eyes look toward lesion
1 finding in Corpus callosum lesion
Split-brain syndrome
2 findings in Nondominant temporal lobe lesion
Impaired nonverbal memory
Impaired musical ability
1 finding in Dominant temporal lobe lesion
Impaired verbal memory / word recognition
3 findings in Caudate nucleus lesion
Behavioral abnormalities (agitation, abulia, psychosis) Speech/language disturbances Movement disorders (choreoathetosis)
4 manifestations of increased ICP
Headache
Impaired consciousness
Focal neurologic deficits / seizures
Cushing triad (hypertension, bradypnea, bradycardia)
2 watershed zones + 2 symptoms when lesion
Anterior/middle cerebral arteries
Posterior/middle cerebral arteries
Upper leg/upper arm weakness
Defects in higher-order visual processing
Anatomy + symptoms in Anterior cerebral artery stroke
Motor + sensory cortices - lower limb
Contralateral paralysis + sensory loss - lower limb