Nervous System: Resting Membrane Potential and Action Potential

These flashcards cover key vocabulary related to the structure and function of neurons, electrical signaling, and neurotransmitter release.

Neuron

The basic functional unit of the nervous system responsible for generating and transmitting electrical signals.

Resting Membrane Potential

The charge difference across the plasma membrane of a neuron when it is not transmitting an impulse, typically more negative inside.

Action Potential

A rapid electrical impulse that travels along the axon of a neuron due to the movement of ions across the membrane.

Cations

Positively charged ions that play a key role in the generation of electrical signals in neurons.

Sodium-Potassium Pump

A membrane protein that actively transports sodium ions out of and potassium ions into the cell to maintain the concentration gradients essential for action potentials.

Diffusion

The movement of ions or molecules from an area of high concentration to an area of low concentration, contributing to the generation of electrical signals.

Voltage-Gated Channels

Membrane proteins that open or close in response to changes in membrane potential, allowing ions to move across the membrane and generate action potentials.

Depolarization

The phase during an action potential when sodium ions (Na+) enter the cell, making the inside of the cell more positive.

Repolarization

The phase following depolarization during which potassium ions (K+) exit the cell, restoring the negative charge inside the cell.

Hyperpolarization

The phase where the membrane potential becomes more negative than the resting potential due to excessive K+ outflow.

Synapse

The junction between two neurons or between a neuron and a target cell where neurotransmitters are released.

Neurotransmitter

Chemicals released from the axon terminal of a neuron that transmit signals across the synapse to the target cell.

Acetylcholine

A common neurotransmitter involved in muscle contraction and the transmission of signals in the nervous system.

Saltatory Conduction

The rapid transmission of action potentials along myelinated axons, where the impulse jumps between nodes of Ranvier.

Refractory Period

The time following an action potential during which a neuron cannot fire another action potential; includes absolute and relative refractory periods.