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When the ions are moving across the membrane during the depolarization and repolarization phases of an action potential they are moving by?
Wiki User
∙ 10y ago
Depends on what stage you are talking about. Stimulus of sodium ions from dendrites of other neurons must reach a threshold. Once that threshold is reached, sodium ions quickly diffuse into the neuron via facilitative diffusion, depolarizing the neuron. Upon this occurring, sodium channels close and potassium ions are pumped out of the neuron via active transport, leading to repolarization of the neuron.
Wiki User
∙ 10y ago
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Almost as soon as the depolarization wave begins a repolarization wave follows it across the membrane this occurs as?
This occurs as K+ diffuses out of the cell.
What is a shift in the electrical potential across a plasma membrane toward 0mv?
Depolarization
What is a difference in electric charge called?
The chemical gradient refers to the imbalance of substances across the membrane. The Electrical Gradient refers to the difference of charges between substances on different sides of the Membrane. The Electrochemical Gradient refers to the combination of the previous two gradients. The short answer is MEMBRANE POTENTIAL.
What effect does the opening of the potassium channels have on the charge difference across the neuron's membrane?
repolarization
During depolarization does the neurons membrane become negative?
Yes. Positive ions (sodium) move across the membrane.
Describe the action of depolarization and repolarization?
Depolarization is due to the influx of Na+ which causes the cell's internal membrane to become more positive, leading to an action potential. Repolarization occurs when K+ leaves the cell causing the interior of the cell to become negative again.
Almost as soon as the depolarization wave begins a repolarization wave follows it across the membrane this occurs as?
This occurs as K+ diffuses out of the cell.
What is a shift in the electrical potential across a plasma membrane toward 0mv?
Depolarization
What is a difference in electric charge called?
The chemical gradient refers to the imbalance of substances across the membrane. The Electrical Gradient refers to the difference of charges between substances on different sides of the Membrane. The Electrochemical Gradient refers to the combination of the previous two gradients. The short answer is MEMBRANE POTENTIAL.
What are pacemaker potentials and the action potential they trigger?
Pacemaker potentials are automatic potentials generated and are exclusively seen in the heart. They arise from the natural "leakiness" of the membrane that pacemaker cells have, resulting in passive movement of both Na+ and Ca2+ across the membrane, rising the membrane potential to about -40mV. This results in a spontaneous depolarization of the muscle that has a rise in the curve that is nowhere near as steep as the action potential of other cells. Upon depolarization, the cell will return back to its resting membrane voltage, and continue the potential again.
What effect does the opening of the potassium channels have on the charge difference across the neuron's membrane?
repolarization
During depolarization does the neurons membrane become negative?
Yes. Positive ions (sodium) move across the membrane.
Opening sodium channels in the in the axon membrane causes?
Depolarization of the cell membrane. When the sodium channels open there is a rush of sodium ions down their concentration gradient into the cell. As they carry positive charge they reduce the potential difference (inside negative) across the membrane of the neuron.
What is a membrane potential?
a voltage or electrical charge across the plasma membrane
Why is there a resting membrane potential across the cell membrane?
sodium/potassium pump
What is the difference between diffusion potential and nernst potential?
The Diffusion Potential is the potential difference across the boundary b/w two electrolytic solutions of different compositions The Nernst Potential is the diffusion potential across a membrane that exactly opposes the net diffusion of a particular ion through the membrane
The difference in the concentrations of a substance across a cells membrane?
action potential
