he source of some infant seizures lies in a mutation of a particular type of voltage-gated Na+ channel. This mutation is associated with a hyperpolarizing shift in the oltage-dependence of activation of the voltage-gated Na+ channel (meaning the channel is activated at more hyperpolarized membrane potentials). What effect would this yper-polarizing shift in voltage dependence have on the activation of voltage-gated Na+ channels? ) The voltage-gated Na+ channels would open at more negative membrane potentials and action potentials would be easier to produce. The voltage-gated Na+ channels would open at more negative membrane potentials and action potentials would be harder to produce. The voltage-gated Na+ channels would open at more positive membrane potentials and action potentials would be easier to produce. ) The voltage-gated Na+ channels would open at more positive membrane potentials and action potentials would be harder to produce.

he source of some infant seizures lies in a mutation of a particular type of voltage-gated Na+ channel. This mutation is associated with a hyperpolarizing shift in the oltage-dependence of activation of the voltage-gated Na+ channel (meaning the channel is activated at more hyperpolarized membrane potentials). What effect would this yper-polarizing shift in voltage dependence have on the activation of voltage-gated Na+ channels? ) The voltage-gated Na+ channels would open at more negative membrane potentials and action potentials would be easier to produce. The voltage-gated Na+ channels would open at more negative membrane potentials and action potentials would be harder to produce. The voltage-gated Na+ channels would open at more positive membrane potentials and action potentials would be easier to produce. ) The voltage-gated Na+ channels would open at more positive membrane potentials and action potentials would be harder to produce.

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter4: Principles Of Neural And Hormonal Communication

Section: Chapter Questions

Problem 3TAHL

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Similar questions

Conformational changes in channel proteins brought about by voltage changes are responsible for opening and closing Na+ and K+ gates during the generation of an action potential. (True or false?)
A common membrane-bound intermediary between the receptor and the effector protein within the plasma membrane is the __________________.
Why does neuronal function require the voltage-gated K+ channels to open moreslowly than the voltage-gated Na+ channels and how would you expect the voltage-gated K+ channels to affect the shape of an action potential curve?
Dendrotoxins, produced by the mamba snakes (Dendroaspis), are inhibitors of the voltage-gated K+ channels. What phase of the action potential would this toxin affect? How would it affect ion permeability during this phase? How would ion movement be affected?
Which of the following statements about voltage gated channels is true? Voltage-gated sodium channels open at a higher (more positive) membrane potential than do potassium-gated channels Voltage-gated sodium channels open at a lower (more negative) membrane potential than do potassium-gated channels Sodium- and postassium-gated channels open at about the same membrane potential, but they have different effects because there are different numbers of the two kinds of channels in neuron cell membranes
In an experiment, the extracellular [Na+] surrounding a nerve cell was reduced from 145 to 45 mM. Which of the following is the most likely effect of this on action potentials? No action potentials would occur because the concentration of extracellular Na+ is too low. The membrane potential would become more negative so the threshold for action potential generation could not be reached. The nerve cell would still produce an action potential but its amplitude would be reduced and the depolarisation phase would be slower. The nerve cell would still produce an action potential but its amplitude would be reduced and the depolarization phase would be more rapid.
• Why would one use the Goldman-Hodgkin-Katz equation? • What is the role of the Na+/K+ pump in establishing ionic concentration differences and membrane potentials across the nerve membrane? • Describe the process of depolarization of the nerve membrane.
Draw details of the repolarization phase of an action potential from the following descriptions of the sequences of AfterHyperPolarization (AHP) and AfterDePolarization (ADP) sequences. Make the distinct phases clear and noticeable (5 % each) A complex AHP consisting of a first component AHP, an ADP, and a second component AHP before repolarization to resting membrane potential a first fast AHP component, followed by a slower AHP, followed by a fast ADP, and a second late AHP component before repolarization to rest
What is the expected resting membrane potential (in mV) of a neuron that is typical in all ways except for possessing an intracellular potassium concentration of 94 mM and double the normal resting permeability to sodium?
In the introduction section the authors wrote “In general, the polarity-dependent mechanisms are recognized to cause membrane depolarization by anodal stimulation which increases cerebral excitability, or membrane hyperpolarization by cathodal stimulation leading to a decrease in neuronal excitability.” Based on this quote what affect, if any, does anodal stimulation have on ion channels?
Describe the contribution of each of the following to the establishment and maintenance of membrane potential: Part A Na+K+ Pump Passive movement of K+ across the membrane Passive movement of Na+ across the membrane Part B Resting membrane potential is approximately -70mV. Explain what resting membrane potential is and what -70mV refers to.
If the postsynaptic cell's plasma membrane were to become substantially more permeable to Na+, you would expect the membrane potential to [depolarize, hyperpolarize] __________________. You would expect the membrane potential to depolarize if the extracellular K+ concentration were to [increase, decrease] ______________. a.) hyperpolarize, decrease b.) depolarize, decrease c.) depolarize, decrease d.) hyperpolarize, increase