Flashcards in 6. Neuropathology Deck (82)
what is the neuronal capacity to regenerate?
limited for neural components, no regen ability for neurons themselves
what is the infrastructure of the nervous system as opposed to that of the rest of the body?
NS = glial rather than fibroblastic.
does the NS have typical lymphoid drainage?
define Primary Neurological Disease
disorders which begin in or are restricted to the NS. ex: Alzheimers, MS, astrocytomas, AMS, Huntingtons, Parkinson's
define Secondary Neurological Disease
conditions that affect the NS as a consequence of non-CNS disease. Ex: metastatic carcinoma, syphilis, HTN, emboli, trauma
define System Disorders
maladies of the whole body which in the NS play a critical role. ex: enzyme def, atherosclerosis, poisonings, hypoxia
what will happen to severely damaged neurons?
eventually they will disappear
a contracted neuron with hypereosinophilia of the cytoplasm and pyknosis of the nucleus has undergone what?
gradual shrinkage of the cell body and withering of the dentritic tree indicates that what has happened?
how much neuronal loss has to occur to be seen microscopically?
if in a Nissl preparation, the Nissl granules have disappeared, what is the problem?
retrograde degeneration following injury or transection of axons will appear as what?
Mineral deposits in damaged neurons is a sign of what?
phagocytosis of a degenerated neuron by macrophages is called what?
what is lipofuscin?
a wear and tear pigment, mixture of lipids and proteins that accumulates during the course of aging
what cells exhibit lipofuscin earlier than others? what are relatively resistant?
inferior olivary nuclei show earlier, purkinje are resistant.
if lipofuscin like material is seen in neurons in early life, what is it a sign of?
what can cause neurons to distend, enlarge, or assume a globular shape?
accumulation of sphingolipids or gangliosides. due to catabolic enzymatic block
what are neurofibrillary tangles?
bundles of abnl filaments seen in disorders such as Alzheimer's
what are inclusions? in what diseases might we see them?
may be nuclear and/or cytoplasmic. seen in Parkinson's (Lewy bodies) or herpes (Cowdry type A inclusions)
what is wallerian degeneration?
degeneration of an axon distal to an injury.
what is dying-back'?
degeneration of the most distal segments of an axon due to inability of the cell body to maintain adequate plasmic flow, or produce needed nutrients.
when is dying back seen?
in some toxic neuropathies, and certain neurodegen diseases
what are axonal spheroids?
focal bulbous swelling of axons. usually the result of injury
what is demyelination: primary vs secondary?
primary: insult to myelin sheath or myelin forming cell
secondary: due to degen of axons as in wallerian, or dying-back.
what is the myelin-forming cell in CNS?
what is the myelin-forming cell in PNS?
when is loss of dendritic branches seen?
dev disorders (both congen and acquired)
what composes neuroglia?
astrocytes, oligodentrocytes, ependymal cells, epithelium of choroid plexus.