Week 5 Flashcards
(174 cards)
Dura mater
Most superficial covering; double layer of collagenous tissue; forms venous sinuses; adhered to skull
Epidural space
potential space that can fill with blood after skull fracture
arachnoid mater
fibroblasts and meningothelial cells; adhered to dura; villi (granulations) penetrate dural venous sinuses to conduct CSF into circulation
subdural space
potential space between dura and arachnoid maters; veins pass through, can be torn in minor trauma
pia mater
layer of cells tightly adhered to brain surface; anchors strands of arachnoid trabecular
subarachnoid space
arachnoid trabecular passes through; with aging, collagen is deposited; also subject to infection, neoplasm infiltration, and hemmorages
Virchow-Robinson space
perivenular space between arterial tunica and pia; continuous with subarachnoid space

Neuron. Large perikaryon; lots of nissl substance (RER), but abscent at axon hillock; large nucleus with prominant nucleolus and dispersed chromatin
Reactive Astrocytes
Response to brain injury. hyperplasia and hypertrophy

Astrocyte. Glial cell; major function is to wrap foot processes around the basement membrane of blood vessels and non-synaptic parts of neurons–nutrient exchange; short and highly branched in gray matter, sparse and straighter in white matter.
protoplastic astrocyte
capillary processes; heavily stained with GFAP

astrocyte stained for GFAP
(cells around neuron)

oligodendrocytes; myelinate CNS; smalelr, rounder, darker nucleus than astro; 2-3 normally found around neuron (excess is perineuronal satellitosis)

ependymal cells. glial-derived epithelium lining ventricles and spinal canal. no basement membrane. absorptive/secretory/propulsive functions

choroid plexus. gilal-derived secretory epithelium; long microvilli with few cells. many mitochondria, golgi, and basal nuclei
layers of neocortex and motor/sensory attributes
molecular (mostly pi), ext granular, ext pyramidal, int granular, int pyramidal, plexiform. motor areas are thicker, pyramidals more prominant in motor areas vs sensory.

red neurons. response to ischemic injury (12-24 hrs). shrunken soma, eosinophilia, loss of Nissl. nuclei often darker w/o nucleolus.

lipofuscin. normal age-related process of oxidized fatty acid accumulation. don’t confuse with SN, DMX, or locus ceruleus of rostral pons (pigmented areas)

flame-shaped cytoplasmic inclusions = neurofibrillary tangle in AD

Lewy Body inclusions
gliosis
common response to diverse injury. Astrocyte hypertrophy and hyperplasia. increased GFAP, larger cytoplasm
Routes of pathogen entry to CNS
Hematogenous, local extension (paranasal sinus, middle ear), retrograde transport form PNS, direct implantation (trauma, surgery)
most common predisposing factor to CNS infection
immunosuppression!
pachymeningitis
infection of dura


























