Why are action potentials usually conducted in one direction?(A) Ions can flow along the axon in only one direction.(B) The brief refractory period prevents reopening of voltagegated Na+channels.(C) The axon hillock has a higher membrane potential thanthe terminals of the axon.(D) Voltage-gated channels for both Na+and K+open in onlyone direction.

Why are action potentials usually conducted in one direction?(A) Ions can flow along the axon in only one direction.(B) The brief refractory period prevents reopening of voltagegated Na+channels.(C) The axon hillock has a higher membrane potential thanthe terminals of the axon.(D) Voltage-gated channels for both Na+and K+open in onlyone direction.

Human Biology (MindTap Course List)

11th Edition

ISBN:9781305112100

Author:Cecie Starr, Beverly McMillan

Publisher:Cecie Starr, Beverly McMillan

Chapter13: The Nervous System

Section: Chapter Questions

Problem 3RQ: Define an action potential.

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Similar questions

Define an action potential.
What happens when a resting neuron’s membranedepolarizes?(A) There is a net diffusion of Na+out of the cell.(B) The equilibrium potential for K+(EK) becomesmore positive.(C) The neuron’s membrane voltage becomesmore positive.(D) The cell’s inside is more negative than the outside
(b) Use Figure Q1(b) of an action potential to answer questions (i) until (iv) below. Choose the correct letter to represent each condition. (i) The neuron cannot fire an action potential because it is in a refractory period. (ii) The membrane potential is about -70 mV. (iii) The voltage-gated Na+ channels activation gates are closed, but the inactivation gates are open. (iv) Both gates of the voltage-gated Na+ channels are open. C Threshold B A E Figure Q1 (b)
A common feature of action potentials is that they(A) cause the membrane to hyperpolarize and then depolarize.(B) can undergo temporal and spatial summation.(C) are triggered by a depolarization that reaches threshold.(D) move at the same speed along all axons.
Which of the following is the most direct result of depolarizingthe presynaptic membrane of an axon terminal?(A) Voltage-gated calcium channels in the membrane open.(B) Synaptic vesicles fuse with the membrane.(C) Ligand-gated channels open, allowing neurotransmittersto enter the synaptic cleft.(D) An EPSP or IPSP is generated in the postsynaptic cell.
Depolarization of a neuron plasma membrane will shift the membrane potential toward (a) 0 mV. (b) -70 mV. (c) -90 mV. (d) a, b, and c are correct.
D Threshold B A . E
Which of the following factors are important in the establishment of the membrane potential at -70 mV? (i) Coulomb force; (ii) Ion concentration; (iii) Length of the axon; (iv) Number of dendrites; (v) Permeability of the cell membrane. Select one: a. (i), (iv), (v). b. (ii), (iii). c. (i), (ii), (v). d. (iii), (iv).
Which factors in the establishment of the membrane potential are considered in the Nernst equation? (i) Coulomb force; (ii) Ion concentration; (iii) Length of the axon; (iv) Number of dendrites; (v) Permeability of the cell membrane. Select one: a. (i), (iii), (iv) b. (ii), (iii) c. (ii), (iv), (v) d. (i), (ii)
What would occur if voltage - regulated Na+ and k+ gates opened at the same time rather than at different times, during the production of an action potential?
Following a current injection in a neuron, the membrane potential changes were recorded. a) Is the produced voltage change a hyperpolarization or a depolarization, and why? b) Is the produced voltage change excitatory or inhibitory, and why? c) What is the reason the voltage change switches from passive to active?
At which point in the graph do voltage-gated potassium channels open? (Base your answer to this question on the graph below depicting an action potential.) A B C D E