Cellular Pathology

Question 1

The principal functional unit of the central nervous system (CNS) is the ___________.

Answer 1

neuron

Question 2

Of all the cells
in the body, neurons have a unique ability to _______, _________ and __________

Answer 2

receive, store, and transmit information.

Question 3

Neurons
of different types and in different locations have __________properties, including functional roles,
distribution of their connections, neurotransmitters used, metabolic requirements, and levels of
electrical activity at a given moment.

Answer 3

** distinct **

Question 4

A set of neurons, not necessarily clustered together in a
region of the brain, may thus show ______________ vulnerability to various insults because it shares
one or more of these properties.

Answer 4

selective

Question 5

Since most mature neurons are incapable of cell division,
destruction of even a small number of neurons essential for a specific function may leave the
individual with a neurologic deficit.

Stem cell populations in the brain may represent a potential
mechanism for repair after injury. [1] The CNS is affected by a number of unique neurological
disorders, and also responds to common insults (e.g., ischemia, infection) in a manner that is
distinct from other tissues.

Question 6

Reactions of Neurons to Injury.
Neurons vary considerably in structure and size throughout the nervous system and within a
given brain region.

Structural specializations associated with neuronal function include those
related to synaptic transmission as well as axonal and dendritic differentiation.

Neurons share
pathways for response to injury, including apoptotic mechanisms, with cells in other tissues.
During development,____________ has an important role in defining neuronal number; it
comes into play in a variety of disease states as well, including certain neurodegenerative
diseases.

Answer 6

neuronal apoptosis

Question 7

The principal patterns of neuronal injury are the following

Answer 7

1. Acute neuronal injury (“red neurons”)
2. Subacute and chronic neuronal injury (“degeneration”)
3. Axonal reaction
4. Neuronal inclusions
5. neuronal intracytoplasmic
   inclusions,

Question 8

________________ refers to a spectrum of changes that accompany
acute CNS hypoxia/ischemia or other acute insults and reflect cell death, either necrosis
or apoptosis(see Fig. 28-13B ).

Answer 8

Acute neuronal injury (“red neurons”)

Question 9

“Red neurons” are evident with_____________ at about 12 to 24 hours after an irreversible hypoxic/ischemic insult.

Answer 9

hematoxylin and eosin
(H&E) preparations

Question 10

The morphologic features of acute neuronal damage consist of __________________________

Answer 10

• shrinkage of the cell body,
• pyknosis of the nucleus,
• disappearance of the nucleolus,
• and loss of Nissl substance,
• with intense eosinophilia of the cytoplasm

Question 11

______________ refers to neuronal death
occurring as a result of a progressive disease process of some duration, as is seen in
certain slowly evolving neurologic diseases such as amyotrophic lateral sclerosis (ALS).

Answer 11

Subacute and chronic neuronal injury (“degeneration”)

Question 12

What is the histologic characteristic of subacute and chornic neuronal injury?

Answer 12

The characteristic histologic feature is

• cell loss, often selectively involving functionally related groups of neurons, and reactive gliosis.

Question 13

In the early stage of neuronal damage in subacute and cic,hat i whrons the best indicator of pathologic process?

Answer 13

When the process is at an early stage, the cell loss is difficult to detect; the associated reactive glial changes are often the best
indicator of the pathologic process.

Question 14

For many of these diseases, there is evidence that
cell loss is because of ___________

Answer 14

apoptosis.

Question 15

Neuronal trans-synaptic degeneration is seen when
there is a destructive process that interrupts the majority of the _________________ input to a group
of neurons.

Answer 15

afferent input

Question 16

_______________-refers to the reaction within the cell body that attends regeneration of
the axon;

Answer 16

Axonal reaction

Question 17

Where is axonal reaction best seen?

Answer 17

it is best seen in anterior horn cells of the spinal cord when motor axons are
cut or seriously damaged.

Question 18

In the axonal reaction there is increased protein synthesis associated with axonal
sprouting. This is reflected in__________________

Answer 18

• enlargement and rounding up of the cell body,
• peripheral displacement of the nucleus,
• enlargement of the nucleolus,
• and dispersion of Nissl substance from the center to the periphery of the cell (central chromatolysis).

Question 19

Neuronal damage may be associated with a wide range of subcellular alterations in the
neuronal organelles and cytoskeleton.

Neuronal inclusions may occur as a** manifestation of aging,** when there are intracytoplasmic accumulations of__________, __________ and ______

Answer 19

complex lipids

(lipofuscin), proteins, or carbohydrates.

Question 20

Abnormal cytoplasmic deposition of complex
lipids and other substances also occurs in genetically determined disorders of
metabolism in which substrates or intermediates accumulate ( Chapter 5 ).

Question 21

In viral infection it
can lead to abnormal intranuclear inclusions, as seen in______________

Answer 21

herpetic infection

rabies

CMV

Question 22

What inclusion is seen in herpetic and what is it called?

Answer 22

intranuclear: *Cowdry
body*

” Yatigidig STD”

Question 23

What type of inclusion is seen in rabies and what is called?

Answer 23

cytoplasmic inclusion: Negri body

Question 24

What type of inclusion is seen in CMV?

Answer 24

both nucleus and cytoplasm as in cytomegalovirus (CMV) infection.

Question 25

What degenerative diseases of the CNS are associated with neuronal intracytoplasmic
inclusions, such as ___________, ______________ and _____________.

These aggregates are highly
resistant to degradation, contain proteins with altered conformation, and may result from
mutations that affect protein folding, ubiquitination, and intracellular trafficking (see
discussion of protein folding in Chapter 1 ).

The disorders may be referred to as
proteinopathies.

There is increasing evidence in many of these diseases that the visible
aggregates are not the basis of cellular injuries; rather, small multimers of the proteins
(oligomers) are the critical mediators of the damage.

Answer 25

• neurofibrillary tangles of Alzheimer disease
• and Lewy bodies of Parkinson disease;
• others cause abnormal vacuolization of the perikaryon and neuronal cell processes in the neuropil (Creutzfeldt-Jakob disease).

Question 26

What is the intracytoplasmic inclusion of Parkinson disease?

Answer 26

Lewy bodies

Question 27

what are the intacytoplasmic inclusion in Creutzfeldt-Jakob disease?

Answer 27

others cause abnormal vacuolization of the perikaryon and neuronal
cell processes in the neuropil

Question 28

The astrocyte derives its name from its_________________.

Answer 28

star-shaped appearance

Question 29

These cells have multipolar,
branching cytoplasmic processes that emanate from the cell body and contain the glial fibrillary
acidic protein (GFAP), a cell type–specific intermediate filament ( Fig. 28-1 ).

Answer 29

Astrocytes

Question 30

What is the function of Astrocytes?

Answer 30

• act as metabolic buffers and detoxifiers within the brain.
• Additionally, through the foot processes, which surround capillaries or extend to the subpial and subependymal zones, they contribute to​ **barrier functionscontrolling the flow of macromolecules between the blood, the cerebrospinal fluid (CSF), and the brain. **

Question 31

________________ is the most important histopathologic indicator of CNS injury, regardless of etiology, and is **characterized by both hypertrophy and
hyperplasia. **

Answer 31

Gliosis (or astrogliosis)

Question 32

What is the appearance of Gliosis?

Answer 32

In this reaction, the nuclei of astrocytes, which are typically round to oval (10 μm
wide) with evenly dispersed, pale chromatin, enlarge, _become vesicular, and develop prominent
nucleoli._The previously scant cytoplasm _expands to a bright pink, somewhat irregular swath
around an eccentric nucleus_, from which emerge numerous stout, ramifying processes; these
cells are called gemistocytic astrocytes

Question 33

What is gemistocytic astrocytes

Answer 33

The previously scant cytoplasm expands to a bright pink, somewhat irregular swath
around an eccentric nucleus, from which emerge numerous stout, ramifying processes;

Question 34

When directly injured, astrocytes can react with_____________. This is seen in acute
insultsthat cause thecell’s ATP-dependent ion channels to fail, as occurs in hypoxia,
hypoglycemia, and toxic injuries.

Answer 34

cytoplasmic swelling

Question 35

The Alzheimer type II astrocyte is a___________________

Answer 35

• gray-matter cell with a large (two to three times normal) nucleus,
• pale-staining central chromatin,
• an intranuclear glycogen droplet,
• and a prominent nuclear membrane and nucleolus.

Question 36

The Alzheimer type II astrocyte is its name is a misnomer,
as it is mainly seen not in Alzheimer disease but in what?

Answer 36

individuals with long-standing hyperammonemia due to chronic liver disease, Wilson disease, or hereditary metabolic disorders of the urea cycle

Question 37

Astrocytes are not spared from processes that cause the formation of cytoplasmic inclusion
bodies

Question 38

. Rosenthal fibers are thick, elongated, brightly eosinophilic, somewhat irregular
structures that occur within astrocytic processes, and contain two heat-shock proteins__________, __________ and ________.

Answer 38

1. αBcrystallin and hsp27)
2. as well as ubiquitin

Question 39

Rosenthal fibers are typically found in regions of______________

Answer 39

• longstanding gliosis;
• they are also characteristic of one type of glial tumor, pilocytic astrocytoma.

Question 40

In Alexander disease, a leukodystrophy associated with a mutations in the gene encoding__________,
abundant Rosenthal fibers are found in periventricular, perivascular, and subpial locations.

Answer 40

GFAP

Question 41

What are Rosenthal fibers?

Answer 41

thick, elongated, brightly eosinophilic, somewhat irregular
structures that occur within astrocytic processes, and contain two heat-shock proteins (αBcrystallin
and hsp27) as well as ubiquitin

Question 42

What are commonly seen in astrocyte cytoplasmic inclusion?

Answer 42

More commonly seen are corpora amylacea, or polyglucosan bodies

Question 43

What are corpora amylacea, or polyglucosan bodies

Answer 43

These are round, faintly
basophilic, periodic acid–Schiff (PAS)–positive, concentricallylamellated structures of 5 to 50
μm in diameter that are located wherever there are astrocytic end processes, especially in the
subpial and perivascular zones.

Question 44

What are the contents of copora amylacea?

Answer 44

• primarily of glycosaminoglycan polymers,
• they also contain **heat-shock proteins and ubiquitin. **

Question 45

Corpora amylacea occur in______________

Answer 45

increasing numbers with advancing age and are thought to represent a degenerative change in the astrocyte.

Question 46

The _____________ that are seen in the cytoplasm of neurons (as well as hepatocytes, myocytes,
and other cells)inmyoclonic epilepsy(Lafora body myoclonus with epilepsy) have a similar
structure and biochemical composition.

Answer 46

Lafora bodies

Question 47

Reactions of Other Glial Cells to Injury.

In contrast to astrocytes, oligodendrocytes and ependyma_________________

Answer 47

do not participate in the active
response to CNS injury and show a more limited repertoire of reactions.

Question 48

Oligodendroglial
cytoplasmic processes _____________

Answer 48

** wrap around exons and form myelin. **

Question 49

​Each oligodendrocyte function to ______________________

Answer 49

myelinates
numerous internodes on multiple axons.

Question 50

Injury or apoptosis of oligodendroglial cells is a feature
of_______________ and _____________.

Answer 50

** acquired demyelinating disorders** and** leukodystrophies. **

Question 51

Oligodendroglial nuclei may harbor
viral inclusions in progressive multifocal leukoencephalopathy. Glial cytoplasmic inclusions,
primarily composed of______________are found in oligodendrocytes in multiple system atrophy
(MSA).

Answer 51

** α-synuclein, **

Question 52

_____________ the ciliated columnar epithelial cells lining the ventricles, do not have specific
patterns of reaction.

Answer 52

Ependymal cells,

Question 53

When there is inflammation or marked dilation of the ventricular system,
disruption of the ependymal lining is paired with__________________

Answer 53

proliferation of subependymal astrocytes to
produce small irregularities on the ventricular surfaces (ependymal granulations).

Question 54

Certain
infectious agents, particularly ____________, may produce extensive ependymal injury, with viral
inclusions in ependymal cells.

Answer 54

CMV

Question 55

Microglia are derived from what germ layer?

Answer 55

mesoderm-derived

Question 56

What is the primary function of microglia?

Answer 56

cells whose primary function is to serve as a fixed macrophage
system in the CNS.

Question 57

Microglia share many surface markers with peripheral monocytes/macrophages
(such as _______ and ____.

Answer 57

CR3 and CD68)

Question 58

Microglia response to injury by?

Answer 58

(1) proliferating;

(2) developing elongated
nuclei (rod cells), as in neurosyphilis;

(3) forming aggregates about small foci of tissue necrosis
(microglial nodules); or

(4) congregating around cell bodies of dying neurons (neuronophagia).

Question 59

In addition to resident microglia,_____________ are the principal phagocytic cells
present in inflammatory foci.

Answer 59

blood-derived macrophages