The Nervous System (Part II): Action Potentials & Neuromuscular Junctions

These flashcards cover key terms and concepts related to action potentials and neuromuscular junctions from the lecture on the nervous system.

Action Potential

An electrical impulse generated by neurons to transmit signals to other cells.

Membrane Potential

The difference in electric potential between the inside and outside of a biological cell, measured in millivolts (mV).

Resting Membrane Potential (RMP)

The membrane potential of a neuron when it is not actively sending a signal, typically around -70mV.

Graded Potential

A change in membrane potential that can lead to an action potential if it reaches a threshold.

Threshold

The critical level of depolarization needed to generate an action potential, around -55mV.

Depolarization

The process by which the membrane potential becomes more positive, leading to an action potential.

Repolarization

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

Hyperpolarization

An increase in membrane potential, making the inside of the cell more negative than the resting state.

All-or-Nothing Principle

The principle that an action potential either occurs fully or does not occur at all based on whether the threshold is reached.

Sodium-Potassium Pump (Na+/K+ ATPase)

A transmembrane protein that pumps sodium out and potassium into the cell to maintain resting membrane potential.

Ligand-gated Channel

An ion channel that opens in response to the binding of a neurotransmitter or ligand.

Voltage-gated Channel

An ion channel that opens or closes in response to changes in membrane potential.

Neuromuscular Junction

The synapse between a motor neuron and a muscle fiber, where neurotransmitters are released to induce muscle contraction.

Acetylcholine (Ach)

A neurotransmitter that can stimulate muscle contraction at the neuromuscular junction.

Glycine

An inhibitory neurotransmitter that can cause hyperpolarization in the postsynaptic cell.

Synaptic Clef

The small gap between the presynaptic neuron and the postsynaptic cell where neurotransmitters are released.