Nerve Tissue Flashcards
What are the supporting cells in the CNS?
oligodendrocytes, astrocytes, microglia, ependymal cells
what are the supporting cells in the PNS?
schwann cells, satellite cells
whats another name for the neurons cell body
Soma or perikaryon
what are the most common neurons in the nervous system?
interneurons (type II golgi) 99.9%
what does anterograde need?
kinesin
what does retrograde need?
dynein
what are the two types of astrocytes?
protoplasmic and fibrous
where do you find protoplasmic astrocytes?
gray matter
where do you find fibrous astrocytes?
white matter
What is myasthenia gravis do?
autoimmune attack on Ach receptors and block them = weakness
What happens in Guillan Barre syndrome
PNS disease, nerve fibers have lymphocytes, macrophages, plasma cells
loss of muscle coordination and cutaneous sensation
what is MS?
destruction of oligodendrocytes, 1) plaque 2) increase astrocytes 3) decrease cellularity
what are islands of gray matter? Where are they found?
nuclei - in deep cerebellum and cerebrum
what are acervuli? Where are they found?
calcified granules found in choroid plexus
blood supply to arachnoid mater
avascular! - but the others are vascular
What does the choroid plexus do? Where is it found?
produces CSF and is found in the lateral, 3rd and 4th ventricle
what layers of the cerebrum are pyramidal cells found?
III and V (external and internal respectively)
what are the 3 layers of gray matter in the cerebellum?
molecular layer (stellate cells and basket cells) purkinje cell layer granular layer (granule cells and type II golgi)
what is unique about the purkinje cell layer in the cerebellum?
its dendrites arborize in molecular layer and the axon extends to granule layer
what is in the endoneurium? How are those produced?
reticular cells produced by schwann cells
what is unique about the perineurium?
tight junctions, cells are contractile
where are pseudo unipolar neurons found and how do they appear in ganglia?
sensory ganglia - larger and close together
where do multipolar neurons occur and how do they appear in ganglia?
autonomic ganglia - small and far apart
what are the features of the BBB? - junctional complex, basal lamina, structure
tight junctions between endothelium, continuous basal lamina, surrounded by foot processes of astrocytes, no fenestrations in cytoplasmic membrane
where are the areas where BBB do not exist?
neurohypophysis, substantia nigra, locus ceruleus
what is wallerian degeneration
anterograde - degren of axon distal to injury
PNS - few days
CNS - few weeks
retrograde can occur - only extends a few internodal segments
what is chromatolysis?
loss of Nissl - 1 - 2 days after an injury
