When a neuron is sufficiently stimulated, it fires an action
potential that travels down the
towards the

As the action potential moves down the axon it causes the
membrane potential in the gap to become more
which stimulates the ion channels located there to open.

Open channels allow _________________         ions to move into
the axon. These ions carry a _________________        charge.

This process of regenerating the action potential at each gap in the myelin sheath continues until the signal reaches the terminal buttons.

At this point, the signal must be transmitted across the synapse.

If the open ion channels on the postsynaptic membrane allow
positive ions to flow into the neuron, then it will become more
___________________    and  ___________________   to fire an action potential.

If the open ion channels on the postsynaptic membrane allow
negative ions to flow into the neuron, then it will become more
___________________    and  ___________________   to fire an action potential.