(from the Latin saltare, to hop or leap) is the propagation of action potentials along myelinated axons from one node of Ranvier to the next.increased velocityo
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What is excitability?
The ability to undergo an action potential in response to a stimulus
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What are association neurons?
A neuron that conducts neural signals from one neuron to another neuron within the CNS
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What are spinal nerves?
PNS nerves that originate from the spinal chord (Cranial nerves are nerves that start in the brain)
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What are Ganglia?
collection of nerve bodies that are outside the CNS
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Where are the oligodendrocytes located?
they are neuroglia in the CNS that create the myelin sheath around the neurons in the CNS. One connects many neurons together
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Are there more neurons or neuroglia (glial cells)?
Neuroglia 9:1 according to the book, 10:1 according to the video.
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: If neurons can’t perform mitosis, where do brain tumors come from?
The glial cells (neuroglia) a tumor is an overgrowth of cells (p203)
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What neuroglia make cerebrospinal fluid?
Ependymal cells (non ciliated) ependymal cells line the passages in the brain where CSF flows (p203) ciliated move the fluid around
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Why is it important that we have an intact blood brain barrier? What cells do this for us?
Many normal substances in the blood are toxic to neurons, astrocytes.
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Name a toxin that can cross the blood brain barrier?
alcohol and street drugs (p204)
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Does a neuron at rest have a potential difference between the inside and the outside of the cell?
Yes according to the book a typical potential difference is -85mV, according to the video an average potential difference is -70mV
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Why can’t an action potential flow both ways down an axon?
Immediately after the action potential, that part of the axon is in its absolute refractory period (a time when no action potential can be stimulated)
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Does the sodium potassium pump require energy? If so why?
Yes because it is pumping ions from areas of low concentration to areas of high concentration.
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What do neurotransmitters do?
They pass an action potential across a synapse. Neuron to neuron or neuron to muscle (p211)
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What does the author relate the resting potential of a neuron to?
A set mouse trap at rest but ready to spring (p210)
