Neuronal Membrane Potential and Action Potentials-2

Flashcards covering key terms and concepts related to neuronal membrane potential, action potentials, and ion channel mechanisms.

Resting Membrane Potential

The potential difference across the plasma membrane of a resting neuron, typically around -70 mV.

Voltage

The measure of the difference in electrical charges between two points.

Current

The flow of electrical charges between two points; dependent on voltage and resistance.

Resistance

The hindrance to current flow; can be caused by insulators or conductors.

Ohm's Law

An expression relating voltage (V), current (I), and resistance (R) given by the formula I = V/R.

Gated Ion Channels

Membrane proteins that open or close in response to specific stimuli, allowing selective ion passage.

Depolarization

A decrease in membrane potential, making the inside of the cell less negative, which occurs when sodium ions enter the cell.

Hyperpolarization

An increase in membrane potential, making the inside of the cell more negative than the resting potential.

Graded Potentials

Local changes in membrane potential that vary in size and are used for short-distance signaling.

Action Potentials

Rapid, large changes in membrane potential that propagate along axons without decay.

Absolute Refractory Period

The period during which a neuron cannot fire another action potential, regardless of stimulus intensity.

Relative Refractory Period

The period following an action potential when a neuron can fire again, but requires a stronger stimulus.

Sodium-Potassium Pump

A membrane protein that pumps three sodium ions out of the cell and two potassium ions into the cell, helping to maintain resting membrane potential.

Saltatory Conduction

Rapid action potential propagation in myelinated axons, where action potentials jump between nodes of Ranvier.

Continuous Conduction

Slow action potential propagation in unmyelinated axons, requiring sequential opening of gated channels.

Electrochemical Gradient

The combined effect of electrical and chemical gradients that influence ion movement across membranes.