During the _____ phase of an action potential, both gates of the voltage regulated sodium channels are open and the voltage regulated potassium channels are closed.

channels are specifically attuned to the action The voltage-gated potential threshold. O cr Na* O K* O Ca2+

Match each type of membrane potential to its definition: The membrane potential at which voltage gated sodium channels open. The membrane potential that triggers the action potential. Threshold potential Change in membrane potential that may or may not reach threshold and that may be depolarizing or hyperpolarizing. Rapid, strong depolarization followed by immediate repolarization. This potential is self-renewing if the right ion channels are nearby. Answer Options: Resting Potential, Threshold Potential, Graded Potential, Action Potential

The concentration of potassium ions inside a nerve cell membrane is higher than the concentration of sodium ions outside the mem-brane, yet the inside of the membrane (where the cation concentra-tion is higher) is negative to the outside. Explain this observation in terms of permeability properties of the membrane.

An influx of positive sodium ions eventually causes closing of the inactivation gates of voltage regulated sodium channels, stopping the influx of positive sodium ions, and thus the final stages of an action potential are regulated by _____ feedback.

An increase in the magnitude of depolarization by a graded potential will increase the threshold potential increase the duration of an action potential increase the frequency of action potentials two of the above

A membrane potential (Vm) labeled axis on the graph In the graph draw the phases of the action potential Include the channels involved and when they open and close matching them to the Vm Indicate the periods in which the action potential can or cannot occur

Which of the following situations in a neuron results in action potentials that have extended depolarization phases? O None of these result in extended depolarization phase. O Compromising the inactivation mechanism in voltage-gated Na* channels. O Stimulating the voltage-gated K* channels. O Inhibiting the voltage-gated Na* channels. O Compromising the inactivation mechanism in voltage-gated K* channels.

rearrange these in the correct order of events in an action potential.

State whether the channels listed would be open or closed at the corresponding numbered phases of the action potential graph.   Phase on Graph Sodium Voltage Gated channels Potassium Voltage Gated channels 1     2     3     4