Electrical Signals Study Guide

T or F: At rest, negative charges tend to gather at the inner -intracellular- surface of the membrane, while positive charges gather on the outer -extracellular- surface of the membrane.

True

T of F:Changes in membrane potential that DO NOT lead to the opening of ion channels are passive responses of the membrane. Such changes are called electrotonic potentials.

True

T or F: Ion concentrations in the giant squid axon are the same concentrations as that found in vertebrate axons.

False

T or F: A neuron at rest has a typical resting membrane potential around -65 mV. The reason the RMP is negative is due to the presence of large negatively charged molecules inside the cell and the fact that the membrane at rest is more permeable to potassium ions.

True

T or F: The Nernst equation can be used to determine equilibrium potential for a given ion when the membrane is permeable to more than one ion.

False

Injecting negative current into the cell will result in which of the following?

Hyperpolarization

T or F: Small depolarizing currents (below threshold) and hyperpolarizing currents are by definition electrotonic potentials.

True

The separation of charge that exist when the neuron is at rest is maintained by which of the following?

the Na-K pump; the lipid bilayer

T or F: At rest, sodium ions are concentrated inside, while potassium ions are concentrated outside the cell.

False

T or F: Chloride ions (Cl^-) are concentrated inside the neuron at rest.

False