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33 Cards in this Set
- Front
- Back
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Tract
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axon group in CNS
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Nerve
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axon group in PNS
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Nucleus
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cell bodies in CNS
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Ganglion
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cell bodies in PNS; covered by specialized endothelial cells
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Soma/cyton/cell body/perikaryon
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cell nucleus and surround cytoplasm in both CNS and PNS
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Gray matter
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CNS with high concentration of somas
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White matter
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area of myelinated axons
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Golgi I neurons
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large cell bodies, typically projection neurons
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Golgi II neurons
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small cell bodies, typically interneurons (localized)
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oligodendrocytes
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glial cells that myelinate several axons in the CNS
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Schwann Cells
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myelinate one segment of one axon in PNS
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Interneuron
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small, process neural info locally within nucleus (in CNS)
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RMP
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-75 to -35 mV inside relative to outside
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Action Potential characteristics
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produced by voltage gated channels
cannot be stopped once initiated -self-propagating -doesn't decrease with distance/time -non-additive |
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Graded Potential characteristics
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not produced by voltage-gated channels (found on dendrites)
-decrease with distance from synapse/time -additive |
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Secretory potential
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type of graded potential associated with release of neurotransmitters from synaptic vesicles
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Type C Nerve fibers
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size 0.1-1.3 um
velocity 0.6-2.0 m/s function: nociception (in inflammatory or visceral pain, thermal sense) unmyelinated |
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Type A(alpha) Nerve fibers
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size 12-22 um
velocity 70-120 m/s function: proprioception, stretch, motor efferent to muscles |
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Anterograde Nerve Transport
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Away from soma/nuclear region, kinesin associated (fast or slow)
Move proteins and membrane components |
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Retrograde Nerve Transport
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From axon terminals to soma, dynein associated (fast)
Recycling of transmitters/membrane structural components |
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Astrocytes
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Glia cells in CNA
metabolic/structural support |
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Astrocytes - protoplasmic
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gray matter
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Astrocytes - fibrous
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white matter
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Astrocytes - radial glia
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form critical bridges in brain development
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Oligodendrocytes
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myelin of CNS
metabolic and ionic support for neurons do not maintain guidance for regrowth |
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Microglia
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rare in normal brain tissue
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Ependyma
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line brain ventricles, serve as barrier between CSF and brain
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Endoneurium
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Reinforcing CT sheath surround individual nerve fibers
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Perineurium
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Dense collagenous rings which bundle axons
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Epineurium
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Dense external CT layer, surrounding peripheral nerves (capillaries embedded within)
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Wallerian degeneration
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degeneration of distal segment of axons
myelin is left behind |
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Growth cone
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Axon extends itself/seals itself off while attempting to re-establish connections after damage to proximal axonal segment
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Soma/Nucleus changes in response to injury
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soma and nucleus enlarge
nucleus move to side of soma opposite axon nuleus becomes pale (increased RNA/DNA transcription) |
