Neuroscience Chapter 2 Key Terms

Front 1

action potential

Back 1

The electrical signal conducted along axons (or muscle fibers) by which information is conveyed from one place to another in the nervous system.

Front 2

depolarization

Back 2

Displacement of a cell’s membrane potential toward a less negative value.

Front 3

electrochemical equilibrium

Back 3

The condition in which no net ionic flux occurs across a membrane because ion concentration gradients and opposing transmembrane potentials are in exact balance.

Front 4

equilibrium potential

Back 4

The membrane potential at which a given ion is in electrochemical equilibrium.

Front 5

hyperpolarization

Back 5

The displacement of a cell’s membrane potential toward a more negative value.

Front 6

ion channels

Back 6

Integral membrane proteins possessing pores that allow certain ions to diffuse across cell membranes, thereby conferring selective ionic permeability.

Front 7

Nernst equation

Back 7

A mathematical relationship that predicts the equilibrium potential across a membrane that is permeable to only one ion.

Front 8

overshoot

Back 8

The peak, positive-going phase of an action potential, caused by high membrane permeability to a cation such as Na+ or Ca2+.

Front 9

receptor potential

Back 9

The membrane potential change elicited in receptor neurons during sensory transduction.

Front 10

resting potential

Back 10

The inside-negative electrical potential that is normally recorded across all cell membranes.

Front 11

rising phase

Back 11

The initial, depolarizing phase of an action potential, caused by the regenerative, voltage-dependent influx of a cation such as Na+ or Ca2+.

Front 12

threshold

Back 12

The level of membrane potential at which an action potential is generated.

Front 13

undershoot

Back 13

The final, hyperpolarizing phase of an action potential, typically caused by the voltage-dependent efflux of a cation such as K+.