Nervous System - Membrane Potential

A collection of vocabulary flashcards on key terms and concepts related to the nervous system and membrane potentials.

Resting Membrane Potential (RMP)

The electrical potential across the plasma membrane of a neuron when it is not transmitting signals, typically around -70 mV.

Graded Potential

A transient change in membrane potential that varies in size and can spread over short distances.

Action Potential

A rapid, all-or-none change in membrane potential that propagates down the axon, characterized by a stereotypical shape.

Hyperpolarization

An increase in membrane potential, making the inside of the cell more negative relative to the outside.

Depolarization

A decrease in membrane potential, making the inside of the cell less negative relative to the outside.

Repolarization

The return of the membrane potential to its resting state after depolarization.

Ligand-gated Ion Channels

Ion channels that open or close in response to binding of a specific ligand, allowing ions to flow across the membrane.

Voltage-gated Ion Channels

Ion channels that open or close in response to changes in membrane potential.

Mechanically-gated Ion Channels

Ion channels that open or close in response to mechanical forces or stretch applied to the membrane.

Equilibrium Potential (Eion)

The membrane potential at which there is no net movement of a given ion across the membrane.

Electrochemical Gradient

The combined influence of the concentration gradient and the electrical gradient on the movement of ions across a membrane.

Absolute Refractory Period

A period during which a second action potential cannot be initiated, regardless of the strength of the stimulus.

Relative Refractory Period

A period following the absolute refractory period during which a stronger-than-normal stimulus can elicit another action potential.

Threshold Voltage (VTh)

The membrane potential that must be reached for an action potential to occur.

Ion Pumps

Membrane proteins that actively transport ions across the membrane to maintain concentration gradients.

Leak Channels

Ion channels that are always open and allow ions to move across the membrane according to their concentration gradients.