The Neuronal Membrane at Rest

These flashcards cover key concepts related to the neuronal membrane at rest, including resting membrane potential, ion channels, and the role of ion pumps in neuronal function.

What is the resting membrane potential of a typical neuron?

About -65 mV.

What are the two main types of nerves involved in a simple reflex?

Sensory neurons (afferent) and motor neurons (efferent).

How is the resting membrane potential established?

Through charge separation, selective permeability of ion channel proteins, and concentration gradients maintained by ion pumps.

What role do potassium channels play in the resting membrane potential?

They are selectively permeable to K+ and are essential in establishing the resting membrane potential.

What is the Nernst Equation used for?

To calculate the equilibrium potential (Eion) for each ion.

What is the main function of ion pumps like the sodium-potassium pump?

To establish and maintain cellular concentration gradients.

What is the driving force on an ion?

The sum of the diffusion and electrostatic forces acting on the ion.

What happens to the membrane potential if extracellular potassium concentration increases?

The membrane depolarizes.

What is a characteristic of ligand-gated ion channels?

They contribute to alterations in postsynaptic potentials (PSP).

Who won the Nobel Prize in 2003 for their work on potassium channels?

MacKinnon.

Describe the structure of the Shaker potassium channel.

It has four subunits arranged to form a selectively permeable pore for K+ ions.

What is the effect of increasing the temperature on the equilibrium potential, Eion?

It will increase the absolute value of Eion.

How do astrocytes help regulate extracellular potassium levels?

They take up K+ when concentrations increase, especially during periods of neural activity.

What is the Goldman equation used for?

To calculate the resting membrane potential considering the relative permeabilities of different ions.

What does the term 'diffusion force' refer to in relation to ions?

It refers to the force on an ion due to its concentration gradient.