Neurone Membrane and Ion Movement

These flashcards cover key concepts regarding the neurone membrane and ion movement during resting and action potential.

Resting Potential

The 'polarised' state of the neurone membrane when the neurone is not transmitting an impulse, with an inside potential of around -70 mV.

Na+/K+ Pump

A carrier that actively pumps 3 Na+ ions out and 2 K+ ions into the neurone using energy from the hydrolysis of ATP.

Permeability

The ability of the neurone membrane to allow ions to pass through; much more permeable to K+ ions than Na+ ions.

Facilitated Diffusion

A process by which ions like K+ pass through the neurone membrane via non-gated channels.

Depolarisation

The phase during the action potential where Na+ ions diffuse into the neurone.

Repolarization

The phase during the action potential when K+ ions diffuse out of the neurone.

Non-Gated Channels

Channels that are permanently open, allowing passive diffusion of K+ ions.

Active Transport

The process of moving ions against their concentration gradient, requiring energy (e.g. via the Na+/K+ pump).

Electrical and Chemical Gradient

Forces that affect the movement of ions; electrical gradient pulls K+ ions back inside, while the concentration gradient pushes them out.

Negatively Charged Proteins

Large proteins trapped inside the neurone that help attract K+ ions back into the neurone.