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8 Cards in this Set
- Front
- Back
What animal is lacking a nervous system?
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Sponges
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What is the organizational system for earthworms and squids?
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Ventral nerve cord, ganglia & a “brain”
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What is the organizational system for cnidarians?
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Nerve nets
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What is the organizational system for vertebrates?
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Brain & dorsal, hollow spinal cord (CNS) and nerves (PNS).
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What are neurons?
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functional units of nervous system
transmit electrical impulses consist of 4 regions (cell body, dendrites, an axon & axon terminals) |
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What are Glial cells?
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do not transmit electrical signals
are 10-50 times more numerous than neurons |
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What are Astrocytes?
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star-shaped cells in CNS that form the blood-brain barrier
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What are Oligodendrocytes?
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form myelin sheaths around axons in the CNS
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