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14 Cards in this Set
- Front
- Back
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what are the 2 main types of CNS cells? which is more common?
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neurons
glia glia 50x more common |
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what percentage of human genes are estimated to be involved in neural fn?
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40%
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what are the 2 main types of glial cells?
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micro (scavenger)
macro (connective) |
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which kind of glia are physiologically & embryologically unrelated to other cell types?
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microglia - derived from macrophages
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in what diseases do microglia scavenge disease debris?
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alzheimers
MS parkinsons AIDS related dementia |
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what are the 3 types of macroglia?
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oligodendrocytes
schwann cells astrocytes |
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what is the function of oligodendrocytes?
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myelin formation around axons in the CNS
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what is the function of schwann cells?
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myelin formation around axons in the PNS
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what is the function of astrocytes?
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send processes to capillaries which induces formation of blood brain barrier
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what additional function do protoplasmic astrocytes have?
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homeostatic - have membrane potential that varies w external K+ concentration; take up K and precursors of GABA for ionic/neurotransmitter homeostasis
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what consequences does myelin loss have? (3)
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Loss of myelin leads to leakage of K+ through voltage-gated channels, hyperpolarization, and failure to conduct action potentials
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how do neurons differ from other secretory cells?
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secretory zone is at end of axon, far away from cell body
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what is wallerian degeneration?
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if the axon is cut, the part distal to the cut degenerates ie cell body maintains function & regeneration
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what kinds of stimuli can nerves have for excitation (3)
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electrical
physical mechanical |
