Why do action potentials travel in one direction, from the axon hillock to the axon terminal? The brief refractory period of voltage-gated Na+ channels prevents them from reopening behind the action potential The Na+/K+ pump uses ATP to depolarize the membrane only ahead of itself The higher resting membrane potential at the axon hillock than at the axon terminal forces the action potential to go down its gradient Ligand-gated channels in the membranes of axons only open in the direction of the axon terminal The inactivation loop associated with voltage-gated K+ channels only allows ions to move in the direction of the axon terminal
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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 than the terminals of the axon. (D) Voltage-gated channels for both $\mathrm{Na}^{+}$ and $\mathrm{K}^{+}$ open in only one direction.
Maitreya E.
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 voltage-gated $\mathrm{Na}^{+}$ channels. (C) The axon hillock has a higher membrane potential than the terminals of the axon. (D) Voltage-gated channels for both Na^ + and $\mathrm{K}^{+}$ open in only one direction.
Ordinarily, the beginning of a neuron's axon (near the cell body) is activated before any other part of the axon, so a wave of action potentials occurs as sodium channels open in the direction of the synaptic terminal. What would happen if you artificially stimulated an axon to reach threshold potential midway along its length, rather than at the connection with the cell body?
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