Excitability and Membrane Potential Vocabulary

Vocabulary flashcards covering core electrophysiology concepts, membrane potential, ion driving forces, and key physiological equations from Chapter 1 through Chapter 7.

Luigi Galvani

An 18th-century scientist known as the father of electrophysiology who demonstrated bioelectricity by connecting a lightning rod to a frog's sciatic nerve to cause muscle contraction.

Bioelectricity

The term used by Luigi Galvani to describe the inherent ability of muscle tissue to pass an electrical current.

Voltmeter

An instrument in an electrophysiology setup that calculates voltage by measuring the charge difference between an intracellular recording lead and an extracellular reference lead.

Chemical driving force

The force acting on ions caused by a concentration gradient, pushing them from an area of higher concentration to an area of lower concentration.

Electrical driving force

The force acting on charged particles due to charge-charge interactions, where opposite charges attract and like charges repel.

Equilibrium potential

The theoretical voltage created across a membrane for a single ion when its chemical driving force and electrical driving force balance each other to become equal and opposite, resulting in zero net flux.

Nernst equation

A mathematical formula used to calculate the equilibrium potential for a single ion, assuming the membrane is completely and exclusively permeable to that ion.

Goldman Hodgkin Katz (GHK) equation

An equation used to calculate overall membrane potential by factoring in both concentration gradients and relative permeabilities ($p$) of multiple ions.

Steady state

A condition in which all moving ions have equal and opposite movements across the membrane, resulting in zero net flux.

Resting membrane potential

The steady-state voltage across a plasma membrane generated by the movement of all permeable ions, typically around $-70\,mV$ in a neuron.

Leaky potassium channels

A family of ion channels open at rest that give potassium the highest relative membrane permeability in resting cells.

Sodium-potassium pump

An active transporter that consumes ATP to move three sodium ions out of the cell and two potassium ions into the cell against their concentration gradients.