Neuro - Normal Anatomy/Function & Response to Injury Flashcards
what cells send, store and receive electrical and chemical signals
neurons
what cells are the local immune cells of CNS (macrophages)
microglia
what cells do regulation, repair, support of the CNS
astrocytes
what cells produce myelin in the CNS and PNS
Oligodendrocytes in CNS
Schwann cells in PNS
what is chromatolysis
neuronal response to injury:
degenerative change with axonal injury, swelling of the nerve cell body
what is seen with shrunken and angular cell bodies with hypereosinophilic cytoplasm and pyknotic nuclei
neuronal response to injury:
ischemic cell change (acute neuronal necrosis) due to excitatory toxicity
when do you see small and large cytoplasmic vacuolation
neuronal response to injury:
lysosomal storage disease (small)
prion diseases (large)
when is ‘wear and tear’ pigment (lipofuscin) (not harmful) seen
neuronal response to injury:
with aging
rabies inclusion bodies
negri bodies intracytoplasmic inclusions
herpes virus inclusion bodies
intranuclear inclusions
canine distemper virus inclusion bodies
intranuclear & intracytoplasmic inclusions
what are the 2 responses of axons to injury
- swelling (spheroid)
- wallerian degeneration (degeneration distal to site of injury)
how are spheroid cells removed
fragmentation then removal by microglial cells (gitter cells)
ascending tracts have degeneration ____ to site of focal axon injury
cranial
descending tracts have degeneration _____ to site of axon injury
caudal
what astrocyte response to injury do you see most often with renal or hepatic encephalopathy
swelling (degeneration) “alzheimer type II astrocytes”
what is primary demyelination? what is a common cause?
oligodendrocyte response to injury:
direct damage to myelin sheath or damage to myelin producing cells sparing the axon
toxin (bromethalin)
what is secondary demyelination?
oligodendrocyte response to injury:
secondary to primary axonal injury (wallerian degeneration)
what is a developmental disorder of myelin? what causes these?
- hypomyelinogenesis
- dysmyelination
pestivirus infection
what are the resident macrophages of the CNS? what are their functions?
microglial cells
- phagocytosis of lipid/myelin debris “gitter cells”
- phagocytosis of dead neurons “neuronophagia”
how does the CNS heal following a small and large lesion
small lesions = proliferation of astrocytes/processes
large lesions = cavitation or cystic spaces
possible causes of spongiosis or status spongiosis
Postmortem artifact
Intramyelinic edema
Loss of axons and/or myelin
Vacuolation of neurons, glial cells or their processes
