Bio lecture 13

Action Potential

Action Potential

A brief reversal of membrane potential with a change of ~100 mV, principal way neurons send signals.

Graded Potential

Short-lived, localized changes in membrane potential that vary in strength.

Depolarization

A decrease in membrane potential, making the inside of the cell less negative.

Repolarization

The process of returning the membrane potential to its resting state after depolarization.

Resting Membrane Potential

The state of a neuron when it is not actively sending a signal, typically around -65 mV.

Voltage-Gated Ion Channels

Channels that open or close in response to changes in membrane potential.

Ligand-Gated Ion Channels

Channels that open or close in response to the binding of specific molecules.

Polarized Membrane

A state of a cell where there is a charge difference across the membrane, with the inside negatively charged.

Na+/K+ Pump

An active transport mechanism that moves 3 Na+ out and 2 K+ in, maintaining the Na+/K+ gradient.

Saltatory Conduction

Faster conduction of action potentials along myelinated axons due to the jumping of impulses between nodes of Ranvier.

Continuous Conduction

Slower conduction of action potentials along unmyelinated axons.

Threshold

The critical level of depolarization that must be reached for an action potential to occur.

Resting Membrane Potential Value

Typically about -65 mV in neurons.

Ion Gated Channels

Channels that change their state in response to specific stimuli, affecting membrane potential.

Axon Diameter Impact

Larger-diameter axons conduct impulses faster due to lower resistance.

Frequency of Impulses

How the nervous system differentiates between weak and strong stimuli based on action potential frequency.