Intro to Neuropathology Flashcards
percentage of genes coding for nervous system-related proteins
50%
selective vulnerability of the hippocampus
hypoxic/ischemic changes
selective vulnerability of the caudate nucleus
Huntington’s disease
selective vulnerability of the motor neurons
amyotrophic lateral sclerosis (ALS)
selective vulnerability of substantia nigra
Parkinson’s disease
type of neurons most resistant to injury
astrocytes
selective vulnerability of oligodendria
myelin disorders
3 types of glial cells
astrocytes, oligodendocytes, ependymal cells (NOT microglia)
if needed, microglia can transform into ..
histiocytes
Nissl substances are representative of
rough endoplasmic reticulum
what part of the neuron stains with H&E?
nucleic acids
major mechanisms of cellular injury
free radical injury, excitotoxic injury
examples of excitotoxic injury
glutamate, aspartate; depolarization; NMDA amino acid receptor
*what is the mechanism of excitotoxic injury?
injured neurons release their excitatory NTs (glutamate), which results in depolarization of the surrounding neurons through the inappropriate activation of NMDA receptors
how can you protect against excitotoxic injury?
antioxidants
excitotoxic injury via NMDA receptors results in..
calcium influx that interferes with mitochondrial function which eventually leads to cell death
characteristics of acute neuronal injury
eosinophilic necrosis (red), hypoxic injury, shrunken cytoplasm, dark smudgy chromatin, irreversible cell death
how long does it take for acute neuronal injury to show up on light microscopy?
12 hrs
hippocampus CA1 region (Sommer’s sector) is most sensitive to what type of injury?
hypoxic-ischemic
subacute and/or chronic type of neuronal injury
degeneration
the changes that occur in the neuron body in response to axonal injury is termed..
axonal reaction (formerly known as central chromatolysis); regenerative attempt
examples of axonal reaction
damage to axon, margination of Nissl substance, central clearing of the cytoplasm, peripheral displacement of the nucleus, rounding of the cell body
term for when an axon is transected, and the proximal portion starts to regenerate and myelinate
Wallerian degeneration
if the BM is not intact during Wallerian regeneration, what is the outcome?
chaotic proliferation of axons, resulting in a painful nodule called traumatic or amputation neuroma