Action Potentials

Flashcards to study important vocabulary related to action potentials in the nervous system.

Action Potential

A rapid change in membrane potential that follows an all-or-nothing principle.

Resting Membrane Potential

The baseline electrical charge of a neuron, approximately -70 mV.

Depolarization

A decrease in the negative charge inside the cell, making it more positive.

Hyperpolarization

An increase in the negative charge inside the cell, making it more negative.

Threshold Potential

The level of membrane depolarization needed to trigger an action potential.

Voltage-Gated Ion Channels

Ion channels in the membrane that open or close in response to changes in membrane potential.

Refractory Period

The time after an action potential during which a neuron cannot fire another action potential.

Sodium (Na+) Channels

Channels that open in response to depolarization, allowing Na+ ions to enter the neuron.

Potassium (K+) Channels

Channels that open to restore the membrane potential by allowing K+ ions to exit the neuron.

Conduction Velocity

The speed at which an action potential propagates along an axon, influenced by axon diameter and myelination.

Myelination

The process of insulating axons with myelin sheaths to increase conduction speed.

Saltatory Conduction

The process by which action potentials jump from one node of Ranvier to another along a myelinated axon.

Local Response

A temporary change in membrane potential that does not propagate action potentials.

Electrotonic Conduction

Passive conduction of a change in membrane potential over short distances.

Ca+ Channels

Ion channels that open in response to neurotransmitter release at synapses.

Excitatory Postsynaptic Potential (EPSP)

A depolarizing potential change in the postsynaptic membrane.

Inhibitory Postsynaptic Potential (IPSP)

A hyperpolarizing potential change in the postsynaptic membrane.

Frequency Coding

The representation of stimulus intensity by the frequency of action potentials.

Spatial Summation

The accumulation of postsynaptic potentials from multiple synapses to trigger an action potential.

Temporal Summation

The accumulation of postsynaptic potentials over time to trigger an action potential.