B7.012 Prework 1: Essentials of Neuropathology

Question 1

neuro cell types

Answer 1

neurons
glia
-astrocytes
-oligodendrocytes
-ependymal cells
-microglia
meningothelial cells

Question 2

2 unique principles of neurons

Answer 2

1. selective vulnerability
2. post mitotic cells
   - no regeneration

Question 3

what causes the formation of red neurons

Answer 3

acute neuronal injury

-anoxia, ischemia, hypoglycemia

Question 4

how are red neurons made

Answer 4

cell atrophy
nuclear pyknosis
loss of Nissl and nucleolus

Question 5

appearance of red neurons on H&E

Answer 5

loss of H leaving E

eosinophilia = red

Question 6

reaction of neurons to injury

Answer 6

1. atrophy
   - retraction of cell body, nuclear pkynosis (smaller, darker)
2. degeneration
   - apoptosis
3. axonal reaction
   - injury to axon leads to cell body swelling
   - central chromatolysis (due to Nissl displacement)
4. Wallerian degeneration
   - degeneration of nerve fibers distal to injury
5. trans-synaptic degeneration
   - atrophy of nerve cells due to loss of afferent input

Question 7

pigments in neurons

Answer 7

lipofuscin

neuromelanin

Question 8

lipofuscin

Answer 8

pigment of old age

Question 9

neuromelanin

Answer 9

pigment produces in substantia nigra

Question 10

types of neuronal inclusions

Answer 10

granulovacuolar degeneration
neurofibrillary tangles
Lewy bodies
viral inclusions

Question 11

what is granulovacuolar change and when is it seen

Answer 11

granules present in cytoplasm

seen in normal aging and AD

Question 12

what are neurofibrillary tangles and when are they seen

Answer 12

dense protein fibrils
stain w silver and H&E
seen in AD

Question 13

what are bunina bodies nd when are they seen

Answer 13

inclusions in large neurons of the spinal cord

seen in motor neuron disease

Question 14

what are lewy bodies and when are they seen

Answer 14

eosinophilic, round intracytoplasmic inclusions with a halo
stain positive for a-synuclein
seen in substantia nigra
hallmark of Lewy body dementia

Question 15

example of a viral inclusion

Answer 15

Negri body

seen in rabies

Question 16

what are glial cells

Answer 16

supportive cells
make up most of brain parenchyma
function in inflammation, repair, and fluid balance

Question 17

neuroectoderm derivatives of glial cells

Answer 17

astrocytes
oligodendrocytes
ependymal cells

Question 18

mesoderm derivatives of glial cells

Answer 18

microglia (macrophages of CNS)

Question 19

astrocytes

Answer 19

small oval nuclei with star like processes
supportive stroma of CNS
metabolic support, detoxifiers
foot processes help as a barrier (BBB)
contain glial fibrillary acidic protein (GFAP)

Question 20

what is GFAP

Answer 20

glial fibrillary acidic protein

intermediate filament of the CNS

Question 21

pathologies of astrocytes

Answer 21

gliosis (astrocytosis)
-indicator of injury, wall off an infarct
Rosenthal fibers
-mark stagnant astrocytes

Question 22

Gemistocytic astrocytes

Answer 22

large, globular cell bodies filled with eosinophilic cytoplasm
seen in reactive or neoplastic processes

Question 23

Alzheimer type 2 astrocytes

Answer 23

pseudoinclusions
seen in metabolic encephalopathy (hepatic failure)
-likely due to increased ammonia

Question 24

Rosenthal fibers

Answer 24

astrocytic process inclusions
composed of HSPs, ab-crystallin
pink, fibrillary, dense material

Question 25

what are Rosenthal fibers seen in

Answer 25

chronic gliosis pilocytic astrocytomas Alexander's disease

Question 26

corpora amylacea

Answer 26

5-50 um structures associated with astrocytic foot processes contain HSP, ubiquitin called "brain sand", basophilic degraded proteins that form inclusions

Question 27

causes of corpora amylacea

Answer 27

degenerative change | increase with age

Question 28

function of oligodendrocytes

Answer 28

make and maintain myelin | stain blue

Question 29

tumors of oligodendrocytes

Answer 29

oligodendrogliomas

Question 30

injuries of oligodendrocytes

Answer 30

myelin loss or abnormal myelin

Question 31

when are inclusions seen in oligodendrocytes

Answer 31

``` infections -JC virus neurodegeneration -demyelination -progressive multifocal leukoencephalopathy ```

Question 32

describe oligodendrocytes nuclear inclusions

Answer 32

smudgy, viral like inclusion

Question 33

ependymal cells

Answer 33

ciliated columnar cells | line the ventricular system

Question 34

injury to ependymal cells

Answer 34

loss infectious -CMV

Question 35

tumors of ependymal cells

Answer 35

ependymomas | -trying to make a ventricle unsuccessfully

Question 36

choroid plexus

Answer 36

CSF producing cells

Question 37

tumors of choroid plexus

Answer 37

papillomas | carcinomas

Question 38

microglial cells

Answer 38

``` resident CNS macrophages actions: -proliferation -elongation -microglial nodules -neuronophagia ```

Question 39

what is neuronophagia by microglial cells

Answer 39

cluster around dying neurons

Question 40

composition of arachnoidal / meningothelial cells

Answer 40

keratin "skin" cells of CNS whorls are seen here