Hodgkin and Huxley Research Quiz

The change in membrane potential from a negative resting state to a more positive value, typically caused by an influx of sodium ions.

The inward current during depolarization is initially driven by sodium ions, followed by an outward current. This pattern contributes to the rising phase of the action potential.

A technique used to measure ionic currents through the cell membrane by controlling the membrane potential at a desired value.

The initial inward current during depolarization is reversed when sodium ions are replaced with choline, an inert cation. This demonstrates the role of sodium in generating the inward current.

Depolarization increases the membrane permeability for sodium ions, allowing them to flow both into and out of the cell.

The relationship between ionic current and membrane potential during depolarization is crucial for understanding the rising phase of the action potential.

The maximum inward and outward ionic currents are influenced by temperature. Increasing temperature by 10 degrees Celsius can triple the rate of change in these currents.

A feedback mechanism that reduces errors caused by the resistance of membrane capacitance during voltage clamp experiments.

The membrane potential gradually returns to its resting state after repolarization.

A state where the membrane is resistant to further depolarization.

The membrane potential is maintained at a more positive value than the resting potential.

Sodium, potassium, and leakage channels are responsible for the movement of ions across the cell membrane.

The likelihood of an ion channel being open is affected by the voltage difference across the membrane.

The electrical signals in nerve cells are primarily due to reversible changes in the permeability of the membrane to sodium and potassium ions.

The Hodgkin-Huxley model explains the behavior of nerve cells by considering the movement of ions through different types of channels.

The total ionic current flowing across the membrane is the sum of the sodium and potassium currents.

The time course of permeability refers to how the permeability of the membrane to specific ions changes over time during an action potential.

Sodium conductance increases rapidly at the start of an action potential, reaching a peak and then declining exponentially.

Potassium conductance increases gradually, forming an S-shaped curve, and remains elevated for a longer duration.

When the membrane is depolarized by 100 mV, the sodium and potassium conductances reach a combined value of approximately 30 millimho/cm².

The movement of sodium and potassium ions across the membrane is independent of each other. Each ion flows according to its own concentration gradient and permeability.

The experiment aimed to investigate the effect of sudden changes in membrane potential on the time course of ionic conductances, particularly sodium conductance.

The experiment focused on the inactivation process, investigating how membrane potential affects the reduction of sodium permeability during the falling phase of the action potential.

Conducting research without understanding its bigger picture or implications leads to wasted effort. Scientific discoveries need context and further exploration to become truly valuable.

A series of five interconnected experiments that revolutionized our understanding of nerve impulses.

The current flowing through a neuron's membrane due to the movement of sodium ions.

The current flowing through a neuron's membrane due to the movement of potassium ions.

The difference in electrical potential between the inside and outside of a nerve cell membrane.

A sudden, short-lasting change in the electrical potential of a nerve cell membrane, caused by the rapid movement of ions across the membrane.

The minimum amount of depolarization needed to trigger an action potential.

The movement of ions across the nerve cell membrane, creating an electrical current.

The ability of a membrane to allow ions to pass through it.

The measure of how easily ions can flow across a membrane.