How does an action potential 'travel' along an excitable membrane
A. It travels in saltatory fashion along unmyelinated axons.
B. It travels by the diffusion of Na+ ions through the cytoplasm.
C. It does not go anywhere; it generates passively spreading depolarizing currents that trigger another action potential farther along the membrane.
D. It travels by depolarizing glial cell
كريمى ~~ of all the things iv lost i miss my mind the most~~ says:
E. It serves as the source of currents that increase the resting charge on adjacent membrane
كريمى ~~ of all the things iv lost i miss my mind the most~~ says:
Opening a Cl- ion channel in the post-synaptic membrane normally holds the membrane at resting levels, around -70 mV. What could be changed to make a Cl- current depolarize the membrane
A. Increase the normal concentration gradient for Cl- across the membrane.
B. Increase the intracellular [Cl-] such that ECl is about -40 mV.
C. Reduce the resting polarization of the membrane to abou
كريمى ~~ of all the things iv lost i miss my mind the most~~ says:
E. Use a different neurotransmitter than GABA to bind to the Cl- ion channel
كريمى ~~ of all the things iv lost i miss my mind the most~~ says:
D. Block the Cl- channels with a toxin or poison.
كريمى ~~ of all the things iv lost i miss my mind the most~~ says:
C. Reduce the resting polarization of the membrane to about -60 mV
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An 'afterhyperpolarization' [complete the sentence]
A. refers to inhibitory postsynaptic potentials.
B. follows all action potentials.
C. is necessary to generate a train of action potentials at the initial segment of an axon.
D. refers to hyperpolarization of an axon terminal (presynaptic inhibition).
E. is an increase in membrane polarity due to the opening of voltage-gated
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Why is excitable membrane refractory immediately after an action potential
A. The afterhyperpolarization prevents excitation of the membrane.
B. It takes many milliseconds to repolarize the membrane, especially if there are no voltage-gated K+ channels present.
C. Because of depolarization block.
D. The 'Na+ pump' requires several milliseconds to restore the Na+ concentration gra
كريمى ~~ of all the things iv lost i miss my mind the most~~ says:
D. The 'Na+ pump' requires several milliseconds to restore the Na+ concentration gradient across the membrane.
E. Na+ channels require time to restore their 'resting' configuration after the membrane potential repolarizes below threshold level.
كريمى ~~ of all the things iv lost i miss my mind the most~~ says:
Opening a Cl- ion channel in the post-synaptic membrane normally holds the membrane at resting levels, around -70 mV. What could be changed to make a Cl- current depolarize the membrane
