EXAM 5 content

what does hyperpolarization of a membrane mean?

• membrane becomes more negative

• membrane becomes more positive

• negative ions to ICF, positive ions ECF

• negative ions to ECF, positive ions to ICF

what is excitatory postsynaptic potentials (EPSP)

• pushes postsynaptic neuron further away from action potential threshold

• brings postsynaptic neuron closer to action potential threshold

• depolarization occurs

• hyperpolarization occurs

what does action potential threshold mean

• Maximum level of depolarization needed for an action potential

• Minimum level of depolarization needed for an action potential

• The minimum level of hyper polarization needed for an action potential

• The point at which an action potential stops

what occurs once a signal reaches threshold

• voltage gated Na+ channels close and action potential starts

• voltage gated Na+ channels open and action potential starts

• voltage gated K+ channels open and action potential starts

• voltage gated K+ channels closed and action potential starts

continuous conduction characteristics

• unmyelinated nerve fibers

• myelinated nerve fibers

• faster

• slower

which of the following correctly characterizes a continuous conduction

• series of AP's like a domino effect, no single AP travels the length of the whole fiber

• conduction happens in multiple directions due to refractory period

• protects and insulates nerve fibers

• minimizes loss of signal by minimizing contact with ECF

what is a refractory period

• The time period during which a neuron fires continuously

• The time period during which a neuron fires at a faster

• The time period during which a neuron is unable to fire again

• The time period during which a neuron fires randomly

what is the difference between an absolute refractory period and a relative refractory period

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which of the following is true about absolute refractory periods

• There is no possible way to open Na+ channels

• membrane is hyperpolarized

• K+ are closed

• No AP can be generated during this time

• membrane is hyperpolarized which means it needs a stronger than normal stimulus to get a new AP

what happens when the diameter of an axon is small

• there is a greater conduction velocity of fluid

• there is less resistance due to less fluid hitting walls

• there is more resistance due to walls of axons

• there is less conduction velocity of fluid