#Self
<li>	Why are action potentials usually conducted in only one direction along an axon?
	The nodes of Ranvier conduct only in one direction.
	The brief refractory period prevents reopening of voltage-gated N channels.	X
	The axon hillock has a higher membrane potential than the terminals of the axon.
	Ions can flow along the axon in only one direction.
	Voltage-gated channels for both Na<sup>+</sup> and K<sup>+</sup> open in only one direction.
		ch48/action_potential.html