8.2 (part 2) - Electrical Nature of Nerves

Action Potential

A rapid rise and fall in membrane potential that occurs when a neuron sends an electrical signal.

Resting Membrane Potential

The voltage difference across a nerve cell membrane during the resting state, typically around -70mV.

Depolarization

The process during an action potential where the membrane potential becomes less negative, typically achieved by opening voltage-gated Na+ channels.

Repolarization

The phase of an action potential where the membrane potential returns to a negative value, mainly through the opening of K+ channels.

Hyperpolarization

A state where the membrane potential becomes more negative than the resting potential, often due to prolonged open K+ channels.

Threshold Potential

The critical level to which a membrane potential must be depolarized to initiate an action potential, typically around -55mV.

Sodium-Potassium Pump

A membrane protein that actively transports sodium ions out of and potassium ions into the neuron to maintain resting potential.

Saltatory Conduction

The process by which action potentials jump from one node of Ranvier to another in myelinated nerve fibers, allowing for faster signal transmission.

Neurotransmitters

Chemical messengers that transmit signals across a synapse from one neuron to another, or to an effector.

Synapse

The junction between two neurons or between a neuron and an effector, where neurotransmitters are released to facilitate signal transmission.