Action Potentials & Ion Movement Review Guide

These flashcards cover key concepts and terms related to action potentials and ion movement for effective studying.

What are the three types of fluids mentioned in relation to total body weight (TBW)?

Extracellular fluid, intracellular fluid, and intravascular fluid.

What is the predominant cation in the intracellular fluid (ICF)?

Potassium (K+).

What is the predominant cation in the extracellular fluid (ECF)?

Sodium (Na+).

What are the major structures found in a neuron?

The major structures include the cell body, axon, and dendrites.

What is the primary function of myelin?

To insulate the axon and increase the speed of action potential propagation.

What does the term 'polarity' refer to in the context of a neuron's cell membrane?

Polarity refers to the difference in charge across the cell membrane, with the inside being negative relative to the outside at resting potential.

What does 'propagation' mean in relation to an axon?

Propagation refers to the process of an action potential traveling down the axon.

What is the difference between 'passive' and 'active' channels?

Passive channels allow ions to flow according to concentration gradients without energy, while active channels require energy (ATP) to move ions against their gradients.

What are the three classes of gated channels?

Voltage-gated, ligand-gated, and mechanically-gated channels.

Which class of gated channel are sodium and potassium channels found in an action potential?

They are voltage-gated channels because they open in response to changes in membrane potential.

What happens during depolarization in an action potential?

Na+ ions flow into the neuron, causing the inside to become more positive.

What occurs during repolarization in an action potential?

K+ ions flow out of the neuron, returning the cell to a more negative internal charge.

What is an all-or-none phenomenon in relation to an action potential?

An action potential either occurs fully or not at all; there's no partial action potential.

What is the sodium-potassium pump, and why is it important?

It is a transport enzyme that moves 3 Na+ out and 2 K+ in, maintaining the necessary ion concentrations for action potentials.

What is the directional movement of Na+ and K+ ions by the Na+/K+ pump?

It moves 3 Na+ ions out of the cell and 2 K+ ions into the cell.

What might happen if there is an electrolyte imbalance of Na+ and K+ in relation to action potentials?

It could disrupt the generation and propagation of action potentials, potentially leading to neurological issues.