Normal Brain Histology Podcast Flashcards
Where are globoid shaped nuclei found?
deep grey nuclei (basal ganglia, thalamus, brainstem)
Where are neuromelanin-containing neurons found?
substantia nigra, locus ceruleus, motor nucleus of vagus
Where are granular neurons found?
hippocampus and cerebellum
Where are Betz cells found?
primary motor cortex
What types of neurons are found in the cerebral cortex?
pyramidal and granular
Where are purkinje cells found?
cerebellar cortex
When is lipofuscin found?
with age, accumulates in neuronal cytoplasm
What is eosinophilic change indicative of?
lethal ischemia/hypoxia or hypoglycemia
How long does eosinophilic chnage take to appear?
12-24 hours
What other cellular changes accompany eosinophilic changes?
shrinkage of neuronal cell body
loss of nissl with cytoplasmic eosinophilia
loss of nucleosis with nuclear pyknosis
What is central chromatolysis indicative of?
switch from manufacture of synaptic t ostructural proteins in response to axonal damage?
Is central chromatolysis reversible?
yes, if axonal repair successful
What additional changes are seen with central chromatolysis?
cellular swelling with margination of nissl substance and nucleus and accumulation of filaments and organelles
What are macroglial cells derived from?
neuroectoderm
What are microglia derive from?
bone marrow
What are the types of macroglia?
astrocytes
oligodendrocytes
ependymal cells
what are some key features of astrocytes?
primary replicating cell in the CNS
round to oval nucelus with radiating cytoplasmic processes
make GFAP
What are the functions of astrocytes?
contribute to blood brain barrier
responsible for repari and scar formation
maintain extracellular environment
structural support
What happens to astrocytes when they respond to various pathologic conditions?
activate: divide and become larger
increase in GFAP (leads to visible eosinophilic cytoplasm)
cells may appear starlike or large and round (gemistocytic)
What is the function of oligodendroglia?
responsible for CNS myelination
What are some features of oligodendroglia?
smaller nucleus and fewer processes than astrocytes
do NOT make GFAP
What occurs with lethal injury of oligodendroglia?
demyelination
What important diseases involving oligodendrocytes?
MS
progressive multifocal leukoencephalopathy
oligodendrogliomas
What are the ependymal cells?
cuboidal to columnar glial ciliated cells that line ventricular surfaces
What is the choroid plexus?
tufts of epithelium projecting into ventricles that secrete cerebrospinal fluid
have papillary architecture
cell juncions between cells ensure CSF Brain barrier
What are the microglia?
monocyte/macrophage-derived cells that reside in the CNS
What do microglia do in response to CNS injury
activate and:
migrate to site of injury, proliferate, differentaite into tissue macrophages (foamy clear cell cytoplasm)
What cellular changes occur during viral infection of the CNS?
astrocytes and microglia form microglial nodules at sites of neuronal injury
What pathomneumonic cellular change is seen in HIV infection?
multinucleated macrophages/giant cells
What are the meningothelial cells?
cover brain and spinal cord
What is neutropil?
network of dendrites and axons in the grey matter (in between the cell bodies)
What are virchow-robin spaces?
potential perivascular space between the large arteries in the subarachnoid space and the parenchyma
