Action Potentials

These flashcards cover essential vocabulary related to action potentials, ranging from definitions of action potentials themselves to various related concepts such as EPSP, IPSP, ion channels, and their functions in neuronal communication.

Action Potential (AP)

A large change of membrane potential that travels down an axon and conveys information from the cell body to the synaptic terminal.

EPSP (Excitatory Postsynaptic Potential)

Increases the likelihood of firing an action potential; typically caused by depolarization.

IPSP (Inhibitory Postsynaptic Potential)

Decreases the likelihood of firing an action potential; typically caused by hyperpolarization.

AP Threshold

The membrane potential that must be reached for an action potential to fire, typically around -55 mV.

Refractory Period

The time period during which a neuron is unable or less likely to fire another action potential, consisting of absolute and relative phases.

Saltatory Conduction

The process by which action potentials jump from one node of Ranvier to the next, allowing for faster propagation along myelinated axons.

Voltage-Gated Na+ Channels

Ion channels that open in response to membrane depolarization, allowing Na+ ions to flow into the cell and contribute to the rising phase of the action potential.

Voltage-Gated K+ Channels

Ion channels that open more slowly than Na+ channels, allowing K+ ions to flow out of the cell, contributing to the falling phase of the action potential.

Resting Membrane Potential (Em)

The baseline membrane potential of a neuron, typically around -70 mV.

Firing Rate

The number of action potentials fired by a neuron per second, used to encode information.