2 Nervous System: Transmembrane Potentials and Action Potentials

This set of flashcards covers key vocabulary and concepts related to transmembrane potentials and action potentials, which are essential for understanding the nervous system.

Transmembrane Potential

The electrical potential difference across a cell membrane due to ion concentrations.

Resting Membrane Potential (RMP)

The voltage of a neuron when it is not transmitting a signal, typically around -70mV.

Depolarization

The process by which a neuron's membrane potential becomes more positive, often due to an influx of Na+ ions.

Hyperpolarization

A state where the membrane potential becomes more negative than the resting membrane potential, often below -70mV.

Action Potential

A rapid rise and fall in voltage across a plasma membrane as a result of ion movement.

Absolute Refractory Period

A time during which a neuron cannot fire another action potential 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 initiate an action potential.

Voltage-gated Channels

Ion channels that open or close in response to changes in the membrane potential, critical for the generation of action potentials.

Nodes of Ranvier

Gaps in the myelin sheath of axons where action potentials are regenerated, allowing for rapid signal propagation.

Sodium Equilibrium Potential

The membrane potential at which the concentration gradient for Na+ ions is balanced by the electrical gradient.

Potassium Equilibrium Potential

The membrane potential at which the concentration gradient for K+ ions is balanced by the electrical gradient.

Leakage Channels

Channels that are always open, allowing ions to diffuse across the membrane and contribute to the resting membrane potential.

Axon Hillock

The region of a neuron where action potentials are initiated, integrating incoming signals from dendrites.

Myelination

The process of forming a myelin sheath around nerve fibers which enhances the speed of signal transmission.