Neuro - Normal Anatomy/Function & Response to Injury

Question 1

what cells send, store and receive electrical and chemical signals

Answer 1

neurons

Question 2

what cells are the local immune cells of CNS (macrophages)

Answer 2

microglia

Question 3

what cells do regulation, repair, support of the CNS

Answer 3

astrocytes

Question 4

what cells produce myelin in the CNS and PNS

Answer 4

Oligodendrocytes in CNS
Schwann cells in PNS

Question 5

what is chromatolysis

Answer 5

neuronal response to injury:
degenerative change with axonal injury, swelling of the nerve cell body

Question 6

what is seen with shrunken and angular cell bodies with hypereosinophilic cytoplasm and pyknotic nuclei

Answer 6

neuronal response to injury:
ischemic cell change (acute neuronal necrosis) due to excitatory toxicity

Question 7

when do you see small and large cytoplasmic vacuolation

Answer 7

neuronal response to injury:
lysosomal storage disease (small)
prion diseases (large)

Question 8

when is ‘wear and tear’ pigment (lipofuscin) (not harmful) seen

Answer 8

neuronal response to injury:
with aging

Question 9

rabies inclusion bodies

Answer 9

negri bodies intracytoplasmic inclusions

Question 10

herpes virus inclusion bodies

Answer 10

intranuclear inclusions

Question 11

canine distemper virus inclusion bodies

Answer 11

intranuclear & intracytoplasmic inclusions

Question 12

what are the 2 responses of axons to injury

Answer 12

1. swelling (spheroid)
2. wallerian degeneration (degeneration distal to site of injury)

Question 13

how are spheroid cells removed

Answer 13

fragmentation then removal by microglial cells (gitter cells)

Question 14

ascending tracts have degeneration ____ to site of focal axon injury

Answer 14

cranial

Question 15

descending tracts have degeneration _____ to site of axon injury

Answer 15

caudal

Question 16

what astrocyte response to injury do you see most often with renal or hepatic encephalopathy

Answer 16

swelling (degeneration) “alzheimer type II astrocytes”

Question 17

what is primary demyelination? what is a common cause?

Answer 17

oligodendrocyte response to injury:
direct damage to myelin sheath or damage to myelin producing cells sparing the axon

toxin (bromethalin)

Question 18

what is secondary demyelination?

Answer 18

oligodendrocyte response to injury:
secondary to primary axonal injury (wallerian degeneration)

Question 19

what is a developmental disorder of myelin? what causes these?

Answer 19

1. hypomyelinogenesis
2. dysmyelination

pestivirus infection

Question 20

what are the resident macrophages of the CNS? what are their functions?

Answer 20

microglial cells

1. phagocytosis of lipid/myelin debris “gitter cells”
2. phagocytosis of dead neurons “neuronophagia”

Question 21

how does the CNS heal following a small and large lesion

Answer 21

small lesions = proliferation of astrocytes/processes

large lesions = cavitation or cystic spaces

Question 22

possible causes of spongiosis or status spongiosis

Answer 22

Postmortem artifact
Intramyelinic edema
Loss of axons and/or myelin
Vacuolation of neurons, glial cells or their processes