These events enter their "all-or-nothing" phase when enough sodium flows into the cell to depolarize the membrane to the threshold potential.
These events are regulated by cyclic nucleotide-gated HCN channels, which generate the "funny" current. The GHK equation determines the state during these events by considering each permanent ion affecting its result. The state of cells prior to this event are maintained by the activity of passive leak channels. The tail end of these events contains a relative refractory period because of slower (*) voltage-dependent potassium channels. Squids increase the propagation speed of these events by raising cross-sectional area, while humans do so by placing spaced myelin sheaths on axons. These events enter their "all-or-nothing" phase when enough sodium flows into the cell to depolarize the membrane to the threshold potential. For 10 points, name these rapid electric membrane potential changes, used in neuron-to-neuron signaling.
These events are regulated by cyclic nucleotide-gated HCN channels, which generate the "funny" current.
action potentials [prompt on stimulatory phase or refractory phase; prompt on depolarization or hyperpolarization; prompt on saltatory conduction] 