Krafts - Sheet1 Flashcards
cells that transmit impulses
neurons
cells that react to injury
Astrocytes
cells that produce myelin
Oligodendrocytes
cells that phagocytose intruders
Microglia
cells that line ventricles
Ependymal cells
“red neurons”
acute injury, dying neurons
Cowdry bodies
associated with herpes
Negri bodies
associated with rabies
Gliosis
proliferation of astrocytes in reaction to injury
Neuronal Storage Diseases
Autosomal recessive enzyme deficiency (most), Result: accumulation of enzyme substrate (sphingolipids, mucopolysaccharides or mucolipids) within neuronal lysosomes Leads to a loss of cognitive function, maybe also seizures. Neuronal ceroid lipofuscinoses, Tay-Sachs disease Clinical senerio; child looks normal, then starts missing developmental milestones….
leukodystrophies
refers to a group of disorders characterized by degeneration of the white matter in the brain.[1] The leukodystrophies are caused by imperfect growth or development of the myelin sheath, the fatty covering that acts as an insulator around nerve fibers.
Tay-Sachs
Deficiency of hexosaminidase A Accumulation of ganglioside in all tissues (nervous system shows the most symptoms) Autosomal recessive; much more common in Ashkenazi Jews Usually begins in early infancy Developmental delay, then paralysis and loss of neurologic function “Cherry-red” spot in retina virtually diagnostic Death within several years
Neuronal Ceroid Lipofuscinoses
Deficiency of enzymes involved in protein modification/degradation Lipofuscin accumulates within neurons, leading to neuronal dysfunction Blindness, mental and motor deterioration, seizures Onset ranges from childhood to adulthood
Leukodystrophies
Group of disorders characterized by myelin abnormalities Most are autosomal recessive Involve lysosomal or peroxisomal enzymes Deterioration of motor skills, spasticity, hypotonia, ataxia Often appear in children who appear normal, but start missing their developmental milestones
Krabbe Disease
Deficiency of galactosylceramidase; Galactocerebroside accumulates, gets converted to galactosylsphingosine (toxic to oligodendrocytes) Loss of myelin and oligodendrocytes in CNS and peripheral nerves “Globoid cells” (fat macrophages/microglial cells) in brain Onset around 3-6 months Rapidly progressive muscle stiffness, weakness
B1 (Thiamine) Deficiency
(Needed to make ATP…?) Usually associated with chronic alcoholism; Wernicke encephalopathy Korsakoff syndrome
Wernicke encephalopathy
confusion, ophthalmoplegia, ataxia hemorrhage and necrosis in *mammillary bodies*, walls of third and fourth ventricles acute, reversible Vit B1 deficiency (thiamine)
Korsakoff syndrome
memory disturbances, confabulation cystic spaces, hemosiderin-laden macrophages in *mammillary bodies*, ventricle walls *thalamic lesions too prolonged, mostly irreversible Vit B1 deficiency (thiamine)
B12 Deficiency
Anemia reversible with B12 administration Subacute combined degeneration of spinal cord lower extremity numbness, ataxia, weakness reversible until paraplegia occurs swelling of myelin layers, vacuolization ascending and descending tracts involved
Hypoglycemia
Abnormally low Blood Sugar; Most vulnerable: large pyramidal neurons of cortex (“pseudolaminar necrosis”) Also vulnerable: hippocampus and cerebellum
Hyperglycemia
Abnormally High Blood Sugar; Most commonly seen in diabetes mellitus Can be associated with either ketoacidosis or hyperosmolar coma Dehydration, confusion, stupor, coma
Carbon Monoxide Poisoning
Injury is due to hypoxia Particularly vulnerable areas: cortex (layers III and V) hippocampus Purkinje cells May see demyelination of white matter tracts
methanol poisoning
Preferentially affects retina Degeneration of ganglion cells May cause blindness
Ethanol and CNS
Acute effects are reversible; chronic effects are not Preferentially affects cerebellum Truncal ataxia, unsteady gait, nystagmus Cerebellar atrophy, loss of granule cells, loss of Purkinje cells, Bergmann gliosis
