Basic Neuro Flashcards
(39 cards)
What is the tumor commonly found in the cerebellum of children?
It stains positive for what marker?
astrocytoma
GFAP
The JC virus infects what neurological cell types?
Usually CD4+ below?
astrocytes & oligodendrocytes (severe demyelinating disease)
CD4+ below 200
What is the name of the macrophages of the CNS?
microglia
HIV can hide out in what CNS cell type and cause chronic HIV encephalitis?
microglia
Oligodendrocytes vs. Schwann cells:
location
how many axons they myelinate
- Oligodendrocytes
- CNS
- myelinate multiple axons
- Schwann Cells
- PNS
- myelinate ONE axon
What cell type is destroyed in MS?
This causes a decrease in what variables?
oligodendrocytes
conduction velocity and length constant
What cell type is affected in Guillan-Barre?
What structure is inflamed?
Schwann cells
endoneurium is inflamed
What is the other name for schwannomas? Why?
acoustic neuroma
classically affects CNVIII
What are the two major factors of saltatory conduction?
- conduction velocity
- length constant
- how far you can go along the neuron until the strength of the AP has decreased to 1/3 its original strength
Classify the different nerve fibers by diameter, myelination & type of signal taht they transmit
- A-alpha
- large, myelinated
- efferent motor fibers
- touch, vibration, position
- A-delta
- small, myelinated
- cold, pain
- C
- small, unmyelinated
- warm, pain
What neuron cell types are most sensitive to ischemia?
How many minutes of ischemia can cause irreversible damage?
hippocampus
purkinje cells
neocortex
straitum (basal ganglia)
4-5 minutes
What are the differences in symptoms between a patient with bulbar palsy and pseudobulbar palsy?
- bulbar palsy (LMN)
- absent jaw / gag reflex
- tongue flaccid / wasted
- pseudobulbar palsy (UMN)
- exaggerated gag reflex
- tongue spastic (no wasting)
- spastic dysarthria
What area is particulary important when considering patients with nausea in response to chemotherapy?
area of postrema: caudal end of 4th ventricle in medulla
outside of blood brain barrier & send signal to central vomit center in the medulla
Where does the brain sense the osmolarity of the blood?
OVLT (organum vasculosum of the lamina terminis)
anterior wall of the third ventricle
What aspect of the pituitary is outside of the blood brian barrier? It releases waht hormones?
posterior pituitary- oxytocin & ADH
Where is NE produced in the brain?
locus cerulus - in the posterior pons near the 4th ventricle
What area of the brain is very active in opiate withdrawl?
locus ceruleus - producing NE
Where is dopamine produced in the central nervous system?
ventral tegmentum (midbrain)
substantia nigra (midbrain)
Where is GABA produced in the brain?
It is produced & broken down by what enzymes? They require what cofactor?
nuceus acumbens
(produced) glutamate decarboxylase
(broken down) GABA transaminase
both require B6
What are the type of GABA receptors and where are they located?
GABA- A & GABA-B (brain)
GABA-C (retina)
Where is serotonin produced in the CNS?
raphe nucleus (pons)
What is the classic triad of serotinin syndrome?
mental status changes
autonomic hyperactivity
neuromuscular abnormalities
How can you differentiate between serotonin syndrome & neuroleptic malignant syndrome?
Both: muscle rigidity, fever, change in mental status, autonomic instability
Serotinin Syndome: clonus
Neuroleptic malignant syndrome: “lead pipe” rigidity, increase CK
Where is Acetylcholine produced in the central nervous system?
basal nucleus of Meynert (subcortex)
